USVI Public Records

Document text (beginning — full text at the TXT link above)

NATIONAL WATER SUMMARY ON WETLAND RESOURCES United States Geological Survey Water-Supply Paper 2425 National Water Summary Series 1983 Hydrologic Events and Issues (U.S. Geological Survey Water-Supply Paper 2250) 1984 Hydrologic Events, Selected Water-Quality Trends, and Ground Water Resources (U.S. Geological Survey Water-Supply Paper 2275) 1985 Hydrologic Events and Surface-Water Resources (U.S. Geological Survey Water-Supply Paper 2300) 1986 Hydrologic Events and Ground-Water Quality (U.S. Geological Survey Water-Supply Paper 2325) 1987 Hydrologic Events and Water Supply and Use (U.S. Geological Survey Water-Supply Paper 2350) 1988 89 Hydrologic Events and Floods and Droughts (U.S. Geological Survey Water-Supply Paper 2375) 1990-91 Hydrologic Events and Stream Water Quality (U.S. Geological Survey Water-Supply Paper 2400) Suggestions and comments on this or any other U.S. Geological Survey publication are most welcome. Remarks should be addressed to: Chief Hydrologist, U.S. Geologocal Survey, 409 National Center, Reston VA 22092 Front Cover: Wetlands along the Homosassa River, at Homosassa, Florida. (Photograph by Judy D. Fretwell, U.S. Geological Survey.) NATIONAL WATER SUMMARY ON WETLAND RESOURCES By U.S. Geological Survey Judy D. Fretweil, John S. Williams, and Phillip J. Redman, Compilers United States Geological Survey Water-Supply Paper 2425 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Gordon P. Eaton, Director- UNITED STATES GOVERNMENT PRINTING OFFICE: 1996 For sale by the U.S. Government Printing Office Superintendent of Documents, M.S. SSOR Washington, D.C. 20402-9328 United States Geological Survey National Water Summary ISBN 0-607-85696-3 Foreword National Water Summary on Wetland Resources is the eighth in a series of reports that describes the condi- tions, trends, availability, quality, and use of the water resources of the United States. This volume describes an often-overlooked water resource wetlands. It gives a broad overview of wetland resources and includes discus- sions of the scientific basis for understanding wetland functions and values; legislation that regulates the uses of wetlands; wetland research, inventory, and evaluation; and issues related to the restoration, creation, and recovery of wetlands. In addition, it presents more-specific information types and distribution, hydrologic setting, trends, and conservation on the wetland resources of each State, the District of Columbia, Puerto Rico, the U.S. Virgin Islands, and several Pacific islands over which the United States has jurisdiction. Wetlands serve as a transitional environment between water bodies and dry land and represent a significant part of the Nation's natural resources. They contain economically important timber, fuel, and food sources; provide esthetic and recreational opportunities; and influence the quantity, quality, and ecological status of water bodies, which include rivers, aquifers, lakes, reservoirs, and estuaries. Wetlands owe their existence, in part, to precipitation, streams, lakes, ground water, and oceans and, in return, perform important functions that affect the quantity and quality of these water resources. Although wetlands are best known for their function as habitat for birds, fish, and other wildlife, their less well known hydrologic and water-quality functions provide such benefits as reducing the severity of flooding and erosion by modifying the flow of water or improving water quality by filtering out contaminants. Public and scientific views of wetlands have changed greatly over time. Only a few decades ago, wetlands were generally considered to be of little or no value. Those who eliminated wetlands through draining or filling were thought of as performing a public service. The role of the wetlands as a breeding ground for disease (prima- rily malaria) and their inability to be exploited for agricultural production caused them to be viewed as an eco- nomic "bad" rather than as a public "good," as they are viewed today. Because of new scientific knowledge, as well as a change in values (as manifested in our Nation's environmental laws), efforts to eliminate wetlands are viewed in a negative light by many. In fact, government and private citizens are making investments in the preservation, remediation, or creation of wetlands. Although we now understand some of the benefits of wetlands and government agencies have established programs to protect them, wetland-protection policies remain a controversial public issue. In keeping with its mis- sion, the U.S. Geological Survey (USGS) has prepared this report with the intent of informing public officials, scientists, and the general public about wetlands. Our purpose is to increase and help improve the understanding of this valuable resource and to provide the scientific information base upon which wise decisions regarding the clas- sification, use, modification, or restoration of wetlands can be made. The hydrologic, biological, and economic consequences of these decisions are substantial and often politically contentious. The USGS takes no position on these issues but hopes to make a positive contribution to the process whereby these decisions are made. The USGS is an earth science information agency. It collects, manages, and disseminates data; conducts inter- pretive scientific studies and research; and publishes the results of these efforts in many forms. The work of the USGS is organized into four thematic areas resources, hazards, environment, and information management. Wetlands are addressed in each of these areas. For example, some wetlands play an integral role in water-resource availability because they are major discharge areas for some aquifers. Some wetlands relate to the hazards theme through their role in the mitigation of floods. Wetlands are affected by environmental changes, such as changes in the source or distribution of water, and, in turn, cause changes in the environment, such as shifts in vegetation or in habitat for birds, fish, and other animals; studies of these changes tie into the environmental theme. And, finally, with respect to the information management theme, the process of classifying, monitoring, and understanding wetlands is dependent upon the hydrologic, geologic, and topographic data collected by the USGS. The USGS has taken this opportunity to draw on the expertise of the many agencies and organizations that have missions directly or indirectly related to wetlands to provide a broad background for government officials, water-resource managers, and the general public. You will note that many of the chapters of this volume have authors from other agencies with key roles in research, classification, or management of wetlands. Production of this volume was a team effort, just as management of wetlands is a team effort. We thank our colleagues in the many other agencies that helped make this report possible. I would like to pay special tribute to the late Dr. Edward T. LaRoe of the National Biological Service, coauthor of the chapter on research. He was a leading wetland re- searcher and played a pivotal role in the evolution of all biological research in the U.S. Department of the Interior. Though this volume merely touches on the many and varied aspects of wetlands, it provides a starting place for further study and a base upon which to begin to understand the values of wetlands to the Nation. We hope it is useful, and we welcome your comments on this volume, as well as on our other products. DIRECTOR ill Hidden River near Homosassa Springs, Florida. (Photograph by Judy D. Fretwell, U.S. Geological Survey.) There has been a lot said about the sacredness of our land which is our body, and the values of our culture which is our soul. But water is the blood of our tribes, and if its life-giving flow is stopped, or it is polluted, all else will die and the many thousands of years of our communal existence will come to an end. Frank Tenorio, Governor, San Felipe Pueblo, 1978 IV National Water Summary Wetland Resources: CONTENTS V Contents Foreword .................................................................................................... Ill Executive Summary, State Summary Highlights, and Introduction ............... 1 Executive summary ............................................................................................. 3 State summary highlights..................................................................................... 7 Introduction ........................................................................................................ 15 Overview of Wetland Resources ................................................................. 17 Technical aspects of wetlands History of wetlands in the conterminous United States Thomas E. Dahl and Gregory]. Allord............ ............................. 19 Wetland definitions and classifications in the United States Ralph W. Tiner.. .......................................................................... 27 Wetland hydrology, water quality, and associated functions Virginia Carter............................................................................. 35 Wetlands as bird habitat Robert E. Stewart, Jr. .................................................................... 49 Wetland management and research Wetland protection legislation Todd H. Votteler and Thomas A. Muir ........................................ 57 Wetland research by Federal agencies Richard E. Coleman, Edward T. LaRoe, and Russell F. Theriot..... 65 Wetland mapping and inventory Bill O. Wilen, Virginia Carter, and J. Ronald Jones ...................... 73 Wetland functions, values, and assessment Richard P. Novitzki, R. Daniel Smith, and Judy D. Fretwell ......... 79 Restoration, creation, and recovery of wetlands Wetland restoration and creation MaryE. Kentula ........................................................................... 87 Effects of Hurricane Andrew (1992) on wetlands in southern Florida and Louisiana John K. Lovelace and Benjamin J. McPherson ............................. 93 Effects of the Great Midwest Flood of 1993 on wetlands James R. Kolva ............................................................................ 97 State Summaries of Wetland Resources ....................................................... 99 Alabama ......................... 101 Maine ............................. 213 Oklahoma....................... 315 Alaska............................. 107 Maryland and District Oregon ........................... 321 Arizona........................... 115 of Columbia................. 219 Pennsylvania................... 327 Arkansas ......................... 121 Massachusetts ................. 225 Puerto Rico ..................... 333 California........................ 127 Michigan ........................ 231 Rhode Island ................... 339 Colorado......................... 135 Minnesota ....................... 237 South Carolina ................ 345 Connecticut.................... 141 Mississippi ...................... 243 South Dakota .................. 351 Delaware ........................ 147 Missouri.......................... 249 Tennessee ....................... 357 Florida ............................ 153 Montana ......................... 255 Texas .............................. 363 Georgia........................... 161 Nebraska ........................ 261 U.S. Virgin Islands .......... 369 Hawaii............................ 167 Nevada ........................... 267 Utah ............................... 375 Idaho .............................. 173 New Hampshire.............. 273 Vermont.......................... 381 Illinois............................. 179 New Jersey...................... 279 Virginia ........................... 387 Indiana ........................... 185 New Mexico ................... 285 Washington .................... 393 Iowa ............................... 191 New York ....................... 291 West Virginia .................. 399 Kansas ............................ 195 North Carolina ................ 297 Western Pacific Islands ... 405 Kentucky......................... 201 North Dakota .................. 303 Wisconsin ....................... 411 Louisiana ........................ 207 Ohio ............................... 309 Wyoming........................ 417 VI National Water Summary Wetland Resources: CONTENTS Supplemental Information ........................................................................... 423 Conversion factors............................................................................................... 424 Glossary.............................................................................................................. 425 Figures 1-13. Maps showing 1. Distribution of wetlands and deepwater habitats in the United States ......................................................................... 5 2. States with notable wetland loss, 1 780's to mid-1980's............. 19 3. Extent of wetlands in Washington County, N. C., circa 1780 and 1900 .............................................................. 20 4. States with notable wetland loss, early 1600'sto 1800.............. 20 5. Major United States land acquisitions between 1800 and 1860 21 6. States with notable wetland loss, 1800 to 1860 ........................ 21 7. Confederate States of America with wetlands depicted for strategic rather than natural resources value ........................... 22 8. Location, estimated original acreage, and drainage of Ohio's historic wetlands .................................................................... 22 9. Wetlands of the Central Valley of California, circa 1850 and 1990....................................................................................... 23 10. States with notable wetland loss, 1860 to 1900 ........................ 23 11. States with notable wetland loss, 1900 to 1950 ........................ 24 12. States with notable wetland loss, 1950 to 1990 ........................ 24 13. Evolution of Horicon Marsh, Wis., from original marsh, to lake, to swamp, to wildlife refuge ....................................... 25 14. Cross sections of selected wetland landscapes showing typical positions of wetlands relative to topographic features .......................................... 27-28 15. Diagram showing classification hierarchy of wetlands and deepwater habitats showing systems, subsystems, and classes ............................... 30 16. Photographs of some wetlands in the United States and chart showing examples of their classification ............................................................. 33 17. Map showing major wetland areas in the United States........................... 35 18. Diagram showing components of the wetland water budget.................... 36 19. Diagram of water budgets for selected wetlands in the United States and Canada..................................................................... 37 20. Cross section showing percentage of transpiration and evaporation from various wetland components........................................................ 38 21. Graph showing monthly streamflow from two wetlands in northern Minnesota............................................................................................. 39 22. Cross section showing ground-water flow systems................................... 39 23. Diagrams showing seasonal changes in storage capacity and evapotranspiration (ET) in wetlands ...................................................... 40 24. Cross sections showing principal hydrogeologic settings for wetlands ..... 42 25. Map showing continuous, discontinuous, and sporadic permafrost areas of Alaska............................................................................................... 43 26. Simplified diagram of the nitrogen cycle in a wetland ............................. 45 27. Diagram showing movement of the freshwater-saltwater interface in an estuary during periods of high flow and low flow............................. 46 28-33. Photographs showing 28. A wetland that is habitat for migrating snow geese.................... 49 National Water Summary Wetland Resources: CONTENTS VII Figures Continued 29. A petroglyph and a clay pot...................................................... 49 30. A baby heron in a wetland environment................................... 50 31. Raccoons.................................................................................. 50 32. An American alligator............................................................... 50 33. An American bittern hidden in vegetation ................................. 50 34. Map showing major flyway corridors for migrating birds in the Western Hemisphere ............................................................................ 51 35. Photograph showing a prothonotary warbler feeding on insects .............. 54 36. Graph showing the relation of pond density increase to number of ducks ................................................................................................ 54 37. Photograph showing duck stamps ........................................................... 55 38. Map showing the location of National Fish and Wildlife Refuge System reserves and Ramsar sites in the United States........................... 56 39. Schematic diagram showing a typical U.S. Army Corps of Engineers review process for Section 404 dredge-and-fill permit request.............. 60 40-41. Graphs showing 40. Status of 40 wetland mitigation projects in south Florida........... 63 41. Cost of Federal agency wetland research, per State, during fiscal year 1992 ...................................................................... 65 42-43. Graphs and charts showing 42. Summary of Federal agency wetland research expenditures by research category during 1992 ............................................... 66 43. Summary of Federal agency wetland research expenditures by wetland type during 1992 ...................................................... 67 44-46. Maps showing 44. Areas of the United States that have been mapped by the National Wetlands Inventory program, and status of those maps, 1996 ............................................................................ 73 45. Areas of the conterminous United States and Hawaii where wetland data have been digitized by the National Wetlands Inventory program, 1996 ........................................................ 74 46. Wetlands depicted by unbounded symbols............................... 75 47. Aerial photograph and map showing wetland features ............................ 76 48. Photographs and chart detailing the sequence of steps in producing National Wetlands Inventory maps ....................................................... 77 49. Photograph showing flooding in the Upper Mississippi River Basin, summer 1993........................................................................................ 79 50-51. Diagrams showing 50. Wetland functions relative to the location of the wetland within a watershed ................................................................. 80 51. Wetland functions and internal and external values .................. 81 52. Photograph showing a view of a restored salt marsh in the Salmon River Estuary on the Oregon coast ................................................................. 87 53. Diagram showing the relative position of a basin substrate, the water table, and differences in vegetation resulting from the degree of basin slope..................................................................................................... 88 54. Photograph of a scientist checking to see if a soiJ sample has the unique coloration typical of wetland (hydric) soils ................................ 89 55. Graph showing a typical performance curve illustrating the comparison of groups of natural wetlands and restored wetlands of the same type and similar size in the same land-use setting ................................. 90 VIII National Water Summary Wetland Resources: CONTENTS Figures Continued 56. Photograph of a restored wetland in Portland, Oreg. ............................... 91 57-58. Maps showing 57. Storm path and areal extent of tropical-storm- and hurricane- force winds produced by Hurricane Andrew, August 1992..... 93 58. Storm-surge elevations at selected points along the coast of Florida................................................................................ . 94 59. Map and graphs showing storm-surge elevations at selected points along the coast of Louisiana ........................................................................... 94 60-61. Photographs showing 60. Hammock and pine forests in Everglades National Park, Fla., after Hurricane Andrew, September 1992............................... 95 61. Dead fish in the Atchafalaya River Basin, La., September 2, 1992...................................................................................... 96 62. Map showing areal extent of flooding in the Upper Mississippi River Basin during the Great Midwest Flood of 1993 ..................................... 97 In "State Summaries of Wetland Resources" Each State summary has photographs and maps showing 1. A well-known wetland in the State. 2. Wetland distribution and physiography. Some State summaries have other maps, diagrams, or photographs showing related wetland resources information. Tables 1. Acreage granted to the States under the authority of the Swamp Land Acts of 1849, 1850, and 1860 .............................................................. 21 2. Examples of wetland definitions used by Federal and State agencies in the United States................................................................................... 29 3. Classes and subclasses of wetlands and deepwater habitats as defined by Cowardin and others (1979) ................................................................. 31 4. Water regime modifiers as defined by Cowardin and others (1979)......... 32 5. Wetland-dependent breeding birds of the conterminous United States including federally endangered or threatened species and subspecies... 52-53 6. Federal programs that have significant effects on wetlands in the United States......................................................................................... 58-59 7. Methods of altering wetlands................................................................... 61 In "State Summaries of Wetland Resources" Each State summary has a table that lists the wetland-related activities of Federal, State, and local government agencies and private organizations in the State. Executive Summary, State Highlights and Introduction Wetland in Bridgeport Valley, California; Sierra Nevada Mountains in the background. (Photograph by Steve Van Denburgh, U.S. Geological Survey.) This wetland is part of a local park near Madison, Wisconsin. (Photograph by Patricia S. Creene.) National Water Summary Wetland Resources: EXECUTIVE SUMMARY 3 Executive Summary This National Water Summary on Wetland Resources documents wetland resources in the United States. It presents an overview of the status of our knowledge of wetlands at the present time what they are, where they are found, why they are important, and the controversies surrounding them, with an emphasis on their hydrology. The "State Summaries of Wetland Resources" part of this National Water Summary describes wetland resources in each State, the District of Columbia (combined with Maryland), Puerto Rico, the U.S. Virgin Islands, and the Western Pacific Islands. The following discussion is a summary of the two parts of this book "Overview of Wetland Resources" and "State Summaries of Wetland Resources." OVERVIEW OF WETLAND RESOURCES The Overview of Wetland Resources part of this National Water Summary consists of three sections "Technical Aspects of Wetlands," "Wetland Management and Research," and "Restoration, Creation, and Recovery of Wetlands" that contain 11 articles providing information on many technical and societal as- pects of wetland resources. The following text summarizes the many facts about wetland resources that these articles report. Technical Aspects Of Wetland Resources Wetlands began disappearing soon after permanent European colonization of the United States. More than one-half of the 221 million acres of wetlands that existed at that time have disappeared; only 103 mil- lion acres remain today. Early in this Nation's history, it was believed that wetlands presented obstacles to development and that wetlands should be eliminated. Federal laws provided incentives for "reclaiming" wet- lands. Only recently people have begun to recognize wetland values and attempted to find ways to preserve them, including changing Federal laws. These attempts have slowed the rate of wetland loss, but losses con- tinue today. The history of wetland losses in the conterminous United States from the time of the first perma- nent European settlement and changes in societal attitudes toward wetlands are documented in "History of Wetlands in the Conterminous United States." Although there is controversy over the precise, legal definition of a wetland, wetlands are scientifically defined by their hydrology, vegetation, and soils. The many different types of wetlands, found in many dif- ferent geographic settings, have different functions. Wetlands can be grouped according to these differences using a nationally consistent terminology (Cowardin and others, 1979) to identify mapping units for Federal and State wetland inventories and to determine wetland status and trends that can aid in planning and man- agement of the resource. The different types of wetlands and the classification systems describing them are presented in "Wetland Definitions and Classifications in the United States." An understanding of the basic hydrologic processes that control the formation, persistence, size, and functions of wetlands is necessary for determining appropriate protective measures for particular wetlands and for determining the success of those measures. The source and distribution of water is a major factor in the differences in wetland types and distribution across the country. Both a favorable geologic setting and an adequate and persistent supply of water are necessary for the existence of a wetland. Different wetlands re- ceive water from different sources; ground water, streams, lakes, tides, snow, and rain. The source of water largely determines its quality, which in turn is largely responsible for wetland vegetation. The wetland veg- etation affects the value of the wetland to animals and people. Wetlands provide many beneficial water-re- lated functions. Some wetlands provide flood control, some provide water for aquifers, others feed streams, some modify climate, others improve water quality, some help maintain the salt balance necessary for estua- rine life, and still others control erosion. "Wetland Hydrology, Water Quality, and Associated Functions" describes the different water-related factors that determine what types of wetlands will be established and what functions each will perform. One of the best known functions of wetlands is as habitat for birds. About one-third of the North Ameri- can bird species use wetlands for water, food, shelter, or breeding. About 138 of the 1,900 bird species in the conterminous United States are wetland dependent. For wetland-dependent birds, habitat loss or degrada- tion usually translates to population loss. Some international treaties The Migratory Bird Treaty and the Ramsar Convention are partly responsible for much of the formal wetland protection in this country. "Wet- lands as Bird Habitat" discusses the relation of birds and wetlands and the effects of wetland losses on birds, and describes some efforts to reduce wetland loss. Wetland Management And Research Many of the benefits that wetlands provide accrue primarily to the general public instead of the private landowners. Landowners usually have few incentives to conserve wetlands that fulfill the needs of the gen- eral public. The Government, therefore, provides incentives and regulates and manages some wetland re- sources to protect the resources from degradation and destruction. Despite current recognition of wetland benefits, potentially conflicting interests still exist, and disagreement on how to protect wetlands has led to differences in local, State, and Federal guidelines. Current wetland-protection regulation commonly requires that wetland loss to development be offset by replacing wetlands by means of mitigation. Section 404 of the Clean Water Act and the "Swampbuster" program are two major Federal vehicles of wetland protection. Coastal National Water Summary Wetland Resources: EXECUTIVE SUMMARY wetlands are provided some protection by the Coastal Zone Management Act and the Coastal Barriers Re- sources Act. Major Federal legislation and initiatives that affect wetlands are discussed in "Wetland Protec- tion Legislation." The recent understanding of wetland values and the benefits that they provide has been broadened by the research efforts. In 1992, wetland research was being done by 18 Federal agencies 12 of which had expen- ditures of $ 1 million or more as part of their mission or responsibilities defined by Congress. In 1992, Fed- eral wetland research expenditures totaled about $63 million. Ecological processes and functions differ with wetland type; therefore, research needs and techniques also differ. Types of Federal wetland research fall into one of the following broad categories: wetland processes, wetland functions, human-induced stresses, delineation and identification, and management. Research needs also differ among agencies; nevertheless, efforts are coordinated to share information and to avoid duplication. Disappearing coastal and bottom-land hardwood wetlands are among the major areas of research. These and other areas of research are discussed in "Wetland Research by Federal Agencies." Wetland mapping is a prerequisite for wetland inventory, regulation, management, protection, and res- toration. Maps are used to analyze wetland trends and the effects of projects, policies, and activities on wet- lands. The U.S. Fish and Wildlife Service has a major responsibility for the mapping and inventory of the Nation's wetlands as mandated by legislation enacted in the past 40 years. This responsibility is satisfied through the agency's National Wetlands Inventory program by producing maps, establishing a wetland data base, publishing and distributing reports on the status and trends of wetlands in this country, and by provid- ing other products related to the identification, mapping, and inventory of wetlands. To date, the National Wetlands Inventory has produced more than 43,300 maps, covering more than 83 percent of the contermi- nous United States, 28 percent of Alaska, and all of Hawaii and the U.S. Territories. Other Federal agencies with wetland mapping and inventory activities, specific to their missions, are the Natural Resources Conser- vation Service (formerly known as the Soil Conservation Service) freshwater wetlands with the potential for agricultural conversion; the National Oceanic and Atmospheric Administration coastal wetlands asso- ciated with marine resources; and the U.S. Geological Survey geographically significant wetlands. More information can be found in "Wetland Mapping and Inventory." Placing a value on wetlands facilitates decisions on which sites should be developed to ensure that the most valuable wetlands are preserved. The value of a wetland lies in the benefits that its habitat, water-qual- ity, and hydrologic functions provide to the environment or to people. Economic value can be placed on some wetland products, but true value goes beyond money. Some wetland values extend beyond the perimeter of the wetland and provide benefits on a local, regional, or global scale. Several systems of wetland evaluation have been or are being developed to assign numerical values to wetland functions in order to allow for the comparison of the worth of one wetland to another. The article "Wetland Functions, Values, and Assessment" discusses three different wetland evaluation methods the Federal Highway Administration's "Wetland Evaluation Technique," the U.S. Environmental Protection Agency's "Environmental Monitoring Assessment Program Wetlands," and the U.S. Army Corps of Engineers' "Hydrogeomorphic Approach." Restoration, Creation, And Recovery For the past few centuries wetlands have been drained or altered to accommodate human needs. This continues to happen, although at a slower rate than in the past. As people have begun to recognize what is lost when wetlands are destroyed, efforts have been made to restore lost wetlands or to create new ones. Restoration and creation of wetlands can help maintain the quality of wetlands and their surrounding eco- systems, and at the same time accommodate the human need for development. Although indications are that some replacement can be successful, full functional replacement has not yet been demonstrated. This is, in part, because of the youth of most restoration and creation projects and, in part, because of the lack of followup on most projects. Scientific knowledge about wetland restoration and creation differs by wetland type, func- tion, and location. We know most about intertidal salt marshes and know much less about replacing forested wetlands because of the time needed for woody vegetation to mature. The more complex the hydrology and ecology of a system, the more difficult it is to restore the system; complete restoration might be impossible in some systems. The ecosystems least likely to be replaced are bogs and fens that have developed over thou- sands of years. "Wetland Restoration and Creation" discusses what is involved in restoring and creating wetlands and chances of being successful. In August 1992, Hurricane Andrew caused massive destruction in southern Florida and in Louisiana two States with some of the largest wetland acreages in the country. The storm passed directly over the Florida Everglades the largest wetland complex in the United States and the Atchafalaya River Basin, La., which contains the largest hardwood swamp in the United States. Although there were some immediate detrimen- tal effects on plants and animals, the long-term effects seem to have been minimal in Florida. In Louisiana, the hurricane may have hastened the coastal erosion and wetland deterioration processes that were already at work. "Effects of Hurricane Andrew (1992) on Wetlands in Southern Florida And Louisiana" describes the effects of this major hurricane on these wetlands. The Great Midwest Flood of 1993, in the Mississippi and Missouri River Basins, was the most devastat- ing flood in United States' history. The areal extent, intensity, and long duration makes this flood unique in the 20th century. Effects of the flood were both detrimental and beneficial to wetlands. Trees were uprooted, islands were eroded, many wetland plants were destroyed, and several bird species fledged few young. Massive sedimentation buried mussels; mammals displaced from the flood plain suffered higher than normal mor- National Water Summary Wetland Resources: EXECUTIVE SUMMARY talities on highways and railroads; the floodwaters transported large amounts of contaminants and nutrients into and down streams; nuisance plants replaced native vegetation; and turbidity made it difficult for some fish to feed. Nevertheless, some fish spawn and feed on inundated flood plains when temperature rise accompanies flooding which was the case in this flooding. Also, some fish habitat was improved by the creation of deep scour holes and massive underwater debris piles that provide cover. Effects of the flooding are discussed in "Effects of the Great Midwest Flood of 1993 on Wetlands." STATE SUMMARIES OF WETLAND RESOURCES State Summaries of Wetland Resources in this National Water Summary provides an overview of the wetland resources of the 50 States, the District of Columbia (combined with Maryland), Puerto Rico, the U.S. Virgin Islands, and several Pacific islands over whose wetlands the United States has some form of jurisdiction. (The term "State" is used in the following discussion for all these geographic areas.) The State summaries contain the following sections: Types and Distribution Wetlands in the United States are of many types. Some of the more familiar names for different kinds of wetlands are swamp, marsh, bog, playa, tideflat, prairie pothole, and pond. Examples of lesser known, local names for different wetland types are cienega, pocosin, muskeg, wet pine flatwoods, and willow carrs. The "Types and Distribution" section of each State summary contains a brief discussion of the wetland types in the State and relates the common, locally known wetland names to the classification system used by Federal agencies to identify and delineate wetlands (see the article "Wetland Definitions and Classifications in the United States" in mis volume for an extensive discussion of wetland types and classification). frv-'x * -'>T -Sx.'f ^r-^-_ K/- -:>-»-\-#»V *X V" ^ l rJ- ; 'V \ >. ' ^ ^;..^ r^/ &*. X-V x-^-'7"-1*- tei ^ >/ * z /" rtfc*4- 0____100 MILES 0 100 KILOMETERS WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the Nation. Because of limitations of scale and source material, some wetlands are not shown ^^^1 Predominantly wetland Predominantly deepwater habitat y/A Area typified by a high density of small wetlands 6 National Water Summary Wetland Resources: EXECUTIVE SUMMARY The "Types and Distribution" section of each State summary also contains a brief discussion of wetland distribution in the State and a map that shows the general distribution of major wetlands. The State maps were derived from a national map that was compiled by the U.S. Fish and Wildlife Service (fig. 1). Because the data used to compile the map differ in reliability from State to State, the distribution of wetlands shown should be considered approximate. Also, because small areas physically cannot be represented at the scale at which the map was compiled, only relatively large wetlands are shown. Hydrologic Setting Example of table 1 used in each State sumrnary (in this case Wetlands can form almost anywhere that water remains on Maryland and the District of Columbia) showing selected wetland- L i j *> r * j j j c *i ,4 related activities of government agencies and private organiza- or near the land surface for an extende? Pe?°d - Some wetlands tions within the State are ephemeral, containing water tor only a few weeks in spring, whereas others are permanently inundated. In arid regions, [Source: Classification of activities is generalized from information provided by , j i- i_ r n u agencies and organizations. .. agency or organization participates in wet some wetlands are wet only in years when rainfall is much land-related activity; ... , agency or organization does not participate in wet- above normal. land-related activity. MAN, management; REG, regulation; R&C, restoration and The factors that determine where and when wetlands form ; °&'' ^ include precipitation amount and timing, evaporation and tran- spiration rates, topography, and geologic characteristics (see Agency or organization "Wetland Hydrology, Water Quality, and Associated Functions" in this volume for a discussion of wetland hydrology). The "Hy- drologic Setting" section of the State summaries provides an .. overview of , he factors that determine wetland hydrology in Natural Resources Conservation Service ................. « each State. Department of Commerce National Oceanic and Trends Atmospheric Administration ....................................... Department of Defense The area of wetlands in the conterminous United States has Army Corps of Engineers .............................................. decreased by about one-half since the founding of the Nation Der?sah^nTwildt|i eeSterii°r in the late 17°°'S (Dah1' 1"°-)' and the dedine is continuing. Geological Survey - -- - rj^£ '"pren(js" seciion of each State summary contains a brief National Biological Service ....................................... ... .. ... ... accounting of wetland losses and gains and lists the major National Park Service .................................................... ... * causes of wetland loss. (For a national perspective of wetland Environmental Protection Agency .................................. trends, see "History and Trends of Wetlands in the Contermi- STATE nous United States" in this volume.) Department of the Environment Water Management Administration ........................... Department of Natural Resources Conservation Chesapeake Bay and Watershed Programs ............ * , -^ -,,^.i Natural Heritage Program .. . ..__. ......_......... . ..... Wetland- conservation efforts are earned out by Federal, Program Open Space .................................................... State, and local government agencies; many private organiza- Office of State Planning .................................................. tions also work to conserve wetlands. The "Conservation" sec- State Highway Administration......................................... tion Of each State summary provides an account of the wetland-conservation activities on each of those levels. In- i,, T- j i o *. JT i i «- cc *. Department of Consumer and duded are P"mary Federal, State, and local regulations affect- Regulatory Affairs .............................................................. ... ... ing wetlands, as well as a discussion of other aspects of wetland Department of Public Works ............................................ ... conservation, such as management, land acquisition, planning, Metropolitan Council of Governments........................... mitigation, research, restoration and creation, delineation, in- Soil and Water Conservation District ............................ . . . ventory, education, and many more. (For a discussion of regu- ^legislation pertaining to wetlands, see "Wetland Chesapeake Bay Foundation ........................................... . ... ... Protection Legislation" in this volume.) Environmental Concern, Inc............................................. ... ... ... Each State summary contains a table (such as the accom- Maryland Land Trust Alliance.......................................... panying table for Maryland and the District of Columbia) that The Nature Conservancy .................................................. ... ... . ... lists seiected wetland-related activities of Federal, State, and local government agencies and private organizations in the State. The information contained in the table and in the "Con- servation" section was compiled in L993; because of the often dynamic nature of government bureaucracies and agency responsibilities, the names of agencies and the activities listed for them can be considered reli- able as of that date and no later. References Cited Cowardin, L.M., Carter, Virginia, Golet, EC-, and LaRoe, E.T., 1979, Classification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Dahl, T.E., 1990, Wetlands Losses in the United States, 1780's to 1980's: Washington, D.C., U.S. Fish and Wildlife Service, 13 p. U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources: HIGHLIGHTS State Summary Highlights Following are a few notable facts about the wetlands of the 50 States, the District of Columbia, Puerto Rico, the Virgin Islands, and several islands of the Pacific Ocean, as reported in the State summaries: Alabama _____________________________________ Wetlands cover about 10 percent of Alabama and range in size from small areas of less than an acre to the 100,000-acre forested tract in the Mobile-Tensaw River Delta. Most of the State's forested wetlands are bottom-land forests in alluvial flood plains. Coastal waters support extensive salt marshes. Wetland acreage in the area that is now Alabama has been reduced by about one-half in the last two centuries. Major causes of wetland loss or alteration have been agricultural and silvicultural conversions in the interior; dredging on the coast; industrial, commercial, and residential development; erosion; subsidence; and natural succession of vegetation. Alaska ______________________________________ Alaska has more area covered by wetlands about 170 million acres than the other 49 States combined. More than 70,000 swans, 1 million geese, 12 million ducks, and 100 million shorebirds depend on Alaskan wetlands for resting, feeding, or nesting. Freshwater Alaskan wetlands include bogs, fens, tundra, marshes, and meadows; brackish and saltwater wetlands include flats, beaches, rocky shores, and salt marshes. Most of the State's freshwater wetlands are peatlands (wetlands that have organic soils), and cover as many as 110 million acres. Alaska's coastal wetlands are cooperatively protected and managed by local governments, rural regions, and the State. Arizona_______________________________________ Less than 1 percent of Arizona's landscape has wetlands. Since the late 1800's, streams and wetlands through- out Arizona have been modified or drained, resulting in the loss of more than one-third of the State's original wetlands. The most extensive Arizona wetlands are in riparian zones and include oxbow lakes, marshes, cienegas, and bosques. Nonriparian wetlands include tinajas, playas, and caldera lakes. Extreme aridity and seasonally varying precipitation are the climatic characteristics that most significantly influence wetland formation and distribution in Arizona. Recreational use of wetlands provides economic benefits to the State. Arkansas _____________________________________ About 8 percent of Arkansas is wetland. The most extensive areas are forested wetlands (swamps and bottom-land forests) along major rivers. Arkansas wetlands, especially those in the Mississippi River Valley, are a critical component of the series of wetlands along the Mississippi Fly way. Wetlands in the Cache-Lower White River system have been designated as one of nine "Wetlands of International Importance" in the United States. Arkansas has lost more wetland acres than any other inland State; most of the loss has been due to conversion to farmland. Arkansas has adopted a program that applies an antidegradation policy to substan- tial alteration of water bodies, including adjacent wetlands. California____________________________________ California's wetlands have significant economic and environmental value, providing benefits such as water- quality maintenance, flood and erosion attenuation, prevention of saltwater intrusion, and wildlife habitat. The Sacramento-San Joaquin Delta regularly harbors as much as 15 percent of the waterfowl on the Pacific Fly way. California has lost as much as 91 percent of its original wetlands, primarily because of conversion to agriculture. Flooded rice fields, which are converted wetlands, covered about 658,600 acres in the mid- 1980's. Rice farmers, State and university researchers, and private organizations are cooperatively studying the feasibility of managing rice fields for migratory waterfowl habitat. Wetland protection is identified as a goal of The California Environmental Quality Act of 1970. Colorado _____________________________________ Wetlands cover about 1 million acres of Colorado 1.5 percent of the State's area. Wetlands occur in all life and climatic zones, from the high mountains to the arid plains and plateaus. Wetland types in Colorado include forested wetlands, willow carrs, fens, marshes, alpine snow glades, and wet and salt meadows. Wet- lands are vital to wildlife in the State, particularly in the arid regions. Colorado's wetland area has decreased by about one-half in the last two centuries, and losses are continuing due to a variety of land-development pressures; however, irrigation and changes in land-use practices have resulted in new wetlands, principally in the San Luis Valley and near Boulder. 8 National Water Summary Wetland Resources: HIGHLIGHTS Connecticut Wetlands cover about 173,000 acres of Connecticut 5 percent of the State's land surface. Connecticut has lost an estimated one-third to three-fourths of its original wetlands over the 200-year period between the 1780's and 1980's. Forested wetlands, primarily red maple swamps, are the predominant wetland type, con- stituting 54 percent of the State's wetlands. Salt marshes, tidal flats, and beaches are the primary coastal wetlands. Wetland protection in Connecticut is carried out at the Federal, State, and (or) local government level, depending on the type and location of the wetland resource. Delaware____________________________________ Wetlands cover about 17 percent of Delaware. Wetlands in Delaware are diverse. Extensive estuarine wet- lands line Delaware Bay and the Atlantic Ocean. Delmarva bays, which are seasonally flooded depressions in the Coastal Plain, contain marsh, shrub, and forest vegetation. More than one-half of Delaware's wetlands have been converted to nonwetland uses or otherwise altered since the 1780's. The State Wetlands Act con- trols development in tidal wetlands, and a proposed statute would establish a State-run nontidal-wetlands regulatory program. Delaware has established its own wetland classification, which has five categories that are based on a wetland's functions and values. District of Columbia______________________________ The District of Columbia has about 250 acres of wetlands; all are palustrine or riverine. Most occur along the tidal reaches of the Potomac and Anacostia Rivers. About 87 percent of the District's wetlands have been drained or filled since the District was established in the 1790's. The National Park Service owns and main- tains most wetlands in the District of Columbia. To alter wetlands, permits must be obtained from the U.S. Army Corps of Engineers and the Department of Consumer and Regulatory Affairs. Wetland conservation is accomplished on Federal and local levels and through the activities of private organizations. Florida______________________________________ Florida has about 11 million acres of wetlands, more than any of the other 47 conterminous States. The abun- dance of wetlands in Florida is due primarily to the low, flat terrain and plentiful rainfall. Most of Florida's wetlands are forested freshwater habitats on stream flood plains, in small depressions and ponds, and cover- ing wet flatwoods. The Everglades, in southern Florida, is a large freshwater marsh that once received surface- and ground-water flows from the Kissimmee River-Lake Okeechobee Basin but which now depends on water releases from canals and water-retention areas. Florida has lost nearly one-half of its wetlands, primarily to agricultural drainage. The State protects wetlands by regulating development in wetland areas, acquiring wetlands and land adjacent to wetlands, and requiring local governments to produce long-range plans for wetland protection. Georgia_____________________________________ Georgia has more than 7.7 million acres of wetlands. Georgia's wetlands are diverse, ranging from mountain seepage areas to estuarine tidal flats. This diversity is primarily due to the wide variety of landforms present, each of which can have different geologic and hydrologic characteristics. The greatest acreages of wetlands are in the coastal plain, where flood-plain wetlands are most extensive and tidal freshwater swamps and estuarine marshes meet. Most of Georgia's wetlands are forested freshwater habitats associated with streams. The Okefenokee Swamp in Georgia, one of the largest freshwater wetlands in the United States, is a mosaic of emergent marshes, aquatic beds, forested and scrub-shrub wetlands, and forested uplands. Hawaii______________________________________ Wetlands constitute less than 3 percent of the State, but they have had a major economic effect on Hawaiian society both before and after European contact. Wetlands are habitats for several species of birds and plants endemic to the Hawaiian Islands. Wetland formation in Hawaii is influenced by climate, topography, and geology; wetlands form where local hydrologic conditions favor water retention near the land surface. Although rainfall is high in many areas of the islands, steep topography and the high permeability of the volcanic rock that forms the islands result in rapid discharge of storm runoff to the ocean as surface-water and ground-water flow. Coastal wetland losses have been greatest on Oahu, where wetlands have been drained and filled for resort, industrial, and residential development. Idaho Most of Idaho's 386,000 acres of wetlands are in flood plains and riparian areas along streams and other water bodies. Since about 1860, when mining and farming began in the State, wetland acreage has decreased by 56 percent. The Idaho State Water Plan states that, insofar as is possible, the State should assume respon- sibility for wetland management and protection. Policy plans made by the Idaho Department of Fish and Game for 1991 to 2005 focus land-acquisition efforts on wetland areas where habitat protection is critical. Many private organizations and groups have participated in projects involving wetland acquisition and restoration. National Water Summary Wetland Resources: HIGHLIGHTS Illinois______________________________________ Wetlands cover about 3.5 percent of Illinois. The largest acreage of wetlands is in the bottom-land forests and swamps along the State's major rivers. Northeastern Illinois also has a large concentration of wetlands. Illinois has lost as much as 90 percent of its original wetlands over the last 200 years; most of the losses have been due to drainage for conversion to agricultural and other uses. The primary State law governing wetlands is the Interagency Wetland Policy Act of 1989, which sets a goal of no net loss of wetlands due to projects funded by the State. Wetlands can be owned and protected by the public as County Forest Preserve Districts. Indiana_____________________________________ About 85 percent of Indiana's wetlands have been lost since the 1780's, primarily because of conversion to agricultural land. The current rate of wetland loss is about 1 to 3 percent of the remaining wetlands per year. Most of the wetlands remaining in Indiana, about 813,000 acres, are in the northeastern part of the State, including extensive wetlands in and near the Indiana Dunes National Lakeshore. The Department of Natural Resources is developing a State wetland conservation plan under a grant from the U.S. Environmental Pro- tection Agency. Several River Basin Commissions are encouraging or pursuing wetland restoration as a flood- control measure with an added benefit of recreation potential. Iowa _______________________________________ Iowa has diverse wetlands that include prairie-pothole marshes, swamps, sloughs, bogs, fens, and ponds. Wetlands cover about 1.2 percent of Iowa, but about 200 years ago more than 11 percent of the State's area was wetland. Conversion of wetlands to agricultural lands, largely in the prairie-pothole region, has been the primary cause of wetland loss. Wetland acreage has been slowly increasing since 1987 as a result of the Prai- rie Pothole Joint Venture, a cooperative Federal, State, county, and private-organization program. The Wet- land Reserve Program of the 1990 Food, Agriculture, Conservation, and Trade Act has the potential to add a substantial number of additional acres. Kansas ______________________________________ Kansas has about 435,000 acres of wetlands, which include sandhill pools along the Arkansas River, playa lakes in western Kansas, freshwater marshes such as those in Cheyenne Bottoms, and salt marshes such as those in Quivira National Wildlife Refuge. Kansas wetlands are important to migrating waterfowl and shore- birds, which depend on the few remaining wetlands in the Central Fly way. Kansas has lost about one-half its wetlands during the last 200 years, mostly due to conversion to cropland and depletion of surface and ground water due to irrigation withdrawals. Wetland preservation and restoration are being accomplished through cooperation among Federal and State agencies and private organizations. Kentucky______________________________________ Wetlands compose less than 2.5 percent of Kentucky's land area, but they have considerable environmental, socioeconomic, and esthetic value. Most Kentucky wetlands lie shoreward of rivers, lakes, and reservoirs and include cypress swamps, bottom-land hardwood forests, marshes, and ponds. More than one-half of Kentucky's original wetlands have been lost, primarily as a conversion to cropland and pastureland; most conversions have been in western Kentucky. The State fosters protection of wetlands through a system of registry and dedication agreements with private entities. Most of Kentucky's wetlands are privately owned. Louisiana ____________________________________ Wetlands are a major source of income for the people of Louisiana, providing revenues from harvesting of fish and shellfish, trapping, and recreation. Most of the State's wetlands are freshwater swamps, but the area of coastal marsh is substantial: Louisiana's coastal marshes represent as much as 40 percent of the coastal marshes in the United States. Wetlands once covered more than one-half of the area that is now Louisiana, but wetland acreage has declined to less than one-third of the State's land surface over the last 200 years. The Louisiana Coastal Wetlands Conservation and Restoration Program implements specific projects to conserve, enhance, restore, and create coastal wetlands. Maine ______________________________________ Maine's wetlands are diverse, ranging from inland swamps and peatlands to coastal salt marshes and mud flats. One-fourth of the State is wetland, and most wetlands are owned by individuals, timber companies, or other private landowners. Land-use changes have led to wetland losses. Early in Maine's history, expansion of fishing and farming communities along the coast resulted in the filling of many coastal wetlands. Wet- lands along inland waterways were converted to agricultural use. Recent losses have been due to urbaniza- tion and other development. Wetland conservation in Maine is a combined effort by Federal, State, and local governments and private organizations and landowners. 10 National Water Summary Wetland Resources: HIGHLIGHTS Maryland ______________________________________ Maryland has about 591,000 acres of wetlands, one-half of which are tidal and one-half nontidal. Extensive estuarine wetlands exist on both sides of the Chesapeake Bay. The Delmarva Peninsula has many wetlands in Delmarva bays, topographic depressions whose wetness is controlled by the water table. About 64 percent of Maryland's wetlands have been converted to nonwetland uses since the 1780's. To obtain permits for altering wetlands in Maryland, a single State-Federal application is submitted to the Maryland Department of the Environment. Wetland conservation in Maryland is accomplished on the Federal, State, and local level and through the activities of private organizations. Massachusetts __________________________________ Wetlands cover about 590,000 acres of Massachusetts, about 12 percent of the State's area. Massachusetts has lost about 28 percent of its original wetlands since the 1780's. Agricultural and urban expansion have caused most of the losses. Forested wetlands, primarily red maple swamps, comprise more than one-half of the State's wetlands; estuarine and marine wetlands account for about one-fifth. Regulatory functions of wetland conservation in Massachusetts are performed at the Federal, State, and local government level, and private organizations are active in land acquisition and management, research, education, and policy review and planning. Michigan_____________________________________ Wetlands cover about 15 percent of Michigan. They provide many benefits, including flood and erosion attenuation, water-quality maintenance, recreation, and wildlife habitat. Michigan's wetlands are largely associated with surface features that are the result of glaciation. Most Michigan wetlands are vegetated by forest or shrubs, but fresh marsh is abundant in coastal and inland areas. About one-half of the State's wet- lands have been converted to other uses, primarily agriculture. The Goemaere-Anderson Wetland Protection Act of 1980 (Public Law 203) and other State statutes are the basis for Michigan's wetland-conservation program. The U.S. Environmental Protection Agency has oversight of the State program. M i n nesota ____________________________________ Minnesota has about 9.5 million acres of wetlands, about one-half the wetland acreage present in predevelopment times. Most wetland losses have been due to drainage for agriculture. Minnesota's wetlands are diverse, ranging from extensive northern peatlands to small prairie potholes. Minnesota has about 150,000 to 200,000 acres of wild rice beds. The centerpiece of Minnesota's efforts to protect wetlands is the Wetland Conservation Act of 1991, which sets a goal of no net wetland loss. The law fills the gap in wetland protec- tion between larger, deepwater habitats that are already protected by Minnesota statute and agricultural wet- lands that are addressed by the Federal "Swampbuster" provisions. Mississippi___________________________________ Wetlands occupy more than 13 percent of Mississippi. Bottom-land forests, swamps and freshwater marshes account for most of Mississippi's wetland acreage; coastal marshes also are extensive. Wetlands in Missis- sippi are a key part of the Lower Mississippi Valley Joint Venture program for the restoration of Mississippi Flyway waterfowl populations. Nearly three-fifths of the State's wetlands have been converted to nonwetland uses, primarily agriculture. Mississippi wetlands have been and continue to be a source of timber, and the cleared, fertile lands have become productive farmland. The Natural Heritage Program identifies and inven- tories priority wetlands. Missouri_____________________________________ Missouri's wetlands occupy 643,000 acres, about 1.4 percent of the State's area. Swamps and other forested wetlands, marshes and fens, and shrub swamps constitute most of the wetland acreage. Missouri's location on the Mississippi Flyway makes the State a favored wintering area for hundreds of thousands of waterfowl and other birds, including bald eagles. Missouri has lost as much as 4.2 million acres (87 percent) of its original wetlands. Most wetland loss has been due to agricultural conversions, urban development, and flood-control measures. The State has developed a wetland-management plan to guide its efforts in the restoration and management of wetlands until the year 2000. Montana _____________________________________ Wetlands cover only a small part of Montana, but their ecological and economic importance far outweighs their relative size. About 27 percent of the wetlands present before 1800 have been converted to other land uses, primarily cropland. Losses to cropland have been particularly great in north-central and eastern Mon- tana, an area that is part of the Nation's most valuable waterfowl production area, the prairie pothole region of the northern Great Plains. Montana has no comprehensive wetland-protection program; however, the Water Quality Bureau of the Montana Department of Health and Environmental Sciences is developing enforce- able water-quality and biological standards specific to Montana wetlands. National Water Summary Wetland Resources: HIGHLIGHTS 11 Nebraska _____________________________________ Nebraska has three wetland complexes recognized as being of international importance as migrational and breeding habitat for waterfowl and nongame birds: the Rainwater Basin wetlands in south-central and south- eastern Nebraska, the Big Bend reach of the Platte River (directly north of the Rainwater Basin), and the Sandhills wetlands in north-central and northwestern Nebraska. Nebraska has lost about 1 million acres of wetlands in the last 200 years about 35 percent of the State's original wetland acreage. Conversion to agricultural use was the primary cause for most of the losses, but urbanization, reservoir construction, high- way construction, and other activities also contributed. Nevada _____________________________________ Wetlands cover less than 1 percent of Nevada but are some of the most economically and ecologically valu- able lands in the State. Benefits of wetlands include flood attenuation, bank stabilization, water-quality improvement, and fish and wildlife habitat. Desert wetlands include marshes in playa lakes, nonvegetated playas, and riparian wetlands; mountain wetlands include fens and other wetlands that form in small glacial lakes. More than one-half of Nevada's original wetlands have been lost, primarily due to conversion of wet- lands to cropland and diversion of water for agricultural and urban use; many others have been seriously degraded by human activities. Some wetlands have been created by mine dewatering and sewage treatment. New Hampshire_________________________________ Wetlands occupy as much as 10 percent of New Hampshire and are an integral part of its natural resources. Swamps and peatlands comprise most of the State's wetlands. Many wetlands have been converted to nonwetland uses such as crop or pastureland. Others have been altered or degraded by urbanization, peat mining, timber harvesting, road building, all-terrain vehicle use, and other causes. New Hampshire regulates wetlands primarily through State law and the rules of the Wetlands Board; local conservation commissions have an advisory role in local wetland protection. During 1987 to 1993, the State acquired diverse wetlands by purchase and donation or protected wetlands through conservation easements. New Jersey____________________________________ New Jersey has about 916,000 acres of wetlands, most of which are in the coastal plain. Forested wetlands are the most common and widely distributed wetlands in the State. Salt marshes are the most common wet- lands in coastal areas. Wetlands are ecologically and economically valuable to the State. Cranberry growing is a significant industry in New Jersey; more than 3,000 acres of cranberry bog wetlands were under private management in 1992. Between the 1780's and 1980's, New Jersey lost about 39 percent of its wetlands. Wet- lands have been drained primarily for crop production and pasturage and filled for housing, transportation, industrialization, and landfills. New Mexico___________________________________ Wetlands cover about 482,000 acres (0.6 percent) of New Mexico; most are in the eastern and northern areas of the State. New Mexico's wetlands include forested wetlands, bottom-land shrublands, marshes, fens, alpine snow glades, wet and salt meadows, shallow ponds, and playa lakes. Riparian wetlands and playa lakes are especially valuable to migratory waterfowl and wading birds. New Mexico has lost about one-third of its wetlands, mostly due to agricultural conversion, diversion of water to irrigation, overgrazing, and urbanization. Other causes of loss or degradation have been mining, clear cutting, road construction, streamflow regulation, and invasion by normative plants. New York____________________________________ New York has about 2.4 million acres of wetlands. One-half of the 160 species identified as endangered or threatened by the Department of Environmental Conservation are wetland dependent. Counties in the Adirondack Mountains and those south and east of Lake Ontario have the largest percentages of wetland area; counties that make up New "fork City and Long Island, along the border with Pennsylvania, and in the Catskills have the smallest percentages. From the 1780's to 1980's, about 60 percent of New York's wetland area was lost, primarily because of conversion to agriculture and other land uses. Counties may facilitate wetland acquisition through the funding of bond acts. North Carolina_________________________________ About 5.7 million acres of North Carolina 17 percent of the State is wetland. The Coastal Plain contains 95 percent of the State's wetlands. Before colonization by Europeans, North Carolina had about 11 million acres of wetlands. Nearly one-third of the wetland alterations in the Coastal Plain have occurred since the 1950's; most have resulted from conversion to managed forests and agriculture. The Roanoke River flood plain has one of the largest intact and least disturbed bottom-land hardwood forests in the mid-Atlantic region. About 70 percent of the rare and endangered plants and animals in the State are wetland dependent. 12 National Water Summary Wetland Resources: HIGHLIGHTS North Dakota. Wetlands once covered about 4.9 million acres of North Dakota 11 percent of the State. By the 1980's, the acreage had decreased to about 2.7 million acres, a loss of about 45 percent. Most of the losses have been caused by drainage for agricultural development. The rate of agricultural conversions in the future will likely depend on crop prices and other economic factors. Most of North Dakota's wetlands are prairie potholes, which provide nesting and feeding habitat for migratory waterfowl and wading birds. About one-half the Nation's duck population originates in the Prairie Pothole Region of North Dakota and other prairie States. Ohio_______________________________________ Ohio's wetlands cover about 1.8 percent of the State. Swamps, wet prairies, coastal and embayment marshes, peatlands, and wetlands along stream margins and backwaters are the most common Ohio wetlands. Wet- land area in Ohio has declined by 90 percent during the last 200 years, from about 5,000,000 acres to about 483,000 acres. Drainage of wetlands for agriculture has been the primary cause of wetland loss, but recre- ational use, fluctuating water levels, urban development, mining, logging, and fire also have contributed. Ohio designates all wetlands as State Resource Waters. As such, wetland water quality is protected from degradation that may interfere with designated uses. Oklahoma___________________________________ Wetlands cover about 950,000 acres (2 percent) of Oklahoma. Wetlands in Oklahoma include bottom-land hardwood forests and swamps; marshes and wet meadows; aquatic-bed wetlands characterized by submersed or floating plants in ponds, lakes, rivers, and sloughs; and sparsely vegetated wetlands such as intermittently flooded playa lakes. Most forested wetlands are in eastern Oklahoma, where precipitation is highest and evaporation lowest. Riparian wetlands and playa lakes in drier western Oklahoma are especially valuable to wildlife. Nearly two-thirds of Oklahoma's original wetlands have been lost as a result of agricultural conver- sions, channelization, impoundment, streamflow regulation, and other causes. O rego n ______________________________________ Wetlands are economically and ecologically valuable to Oregon and can be found statewide. Oregon had nearly 1.4 million acres of wetlands as of the mid-1980's, a decline of more than one-third over the previous 200 years. Most of the losses were due to conversion to agricultural uses, primarily in the Willamette River Valley and Upper Klamath Basin. To improve the effectiveness and efficiency of Oregon's efforts to con- serve, restore, and protect wetlands, the State has developed the Wetland Conservation Strategy. The strat- egy is based on the recommendations of advisory committees representing Federal, State, and local agencies and interest groups. Pennsylvania About 1.4 percent (404,000 acres) of Pennsylvania is covered by wetlands. Deciduous and forested wetlands are the most common types, followed by open water, marshes, shrub wetlands, and others. Wetlands are most densely distributed in the glaciated northwestern and northeastern parts of the State. Wetland area in Penn- sylvania has decreased by more than one-half in the last 200 years. The primary causes of wetland loss or degradation have been conversion to cropland, channelization, forestry, mining, urban development, and the construction of ponds and impoundments. About 50 private conservancy organizations in the State work to protect and preserve natural lands, including wetlands, on a local level. Puerto Rico Wetlands in Puerto Rico are diverse, ranging from interior montane wetlands of the rain forest to intertidal mangrove swamps along the coast. Puerto Rico's wetlands are valuable natural resources that provide habitat for wildlife and a water supply for several large cities. Nearly all of Puerto Rico's wetlands have been modified by man historically for sugar cane agriculture and more recently for housing development, transportation, tourist facilities, and other types of development. Wetland restoration efforts are underway at several locations throughout Puerto Rico; an example is the freshwater wetlands of Laguna Cartagena, once one of the most important waterfowl habitats on the island. Rhode Island __________________________________ Wetlands cover about 65,000 acres of Rhode Island, about 10 percent of the State's area. Forested wetlands, primarily red maple swamps, are the most abundant wetland type and account for nearly three-quarters of the State's wetlands. Once more common in Rhode Island, Atlantic white cedar wetlands are now found mostly in the southwestern part of the State. Wetlands are regulated primarily at the State-government level in Rhode Island; different agencies regulate coastal and freshwater wetlands. Local land-use controls are an additional wetland-protection measure. Many of Rhode Island's natural resources have been acquired and protected through cooperative efforts of private and public entities. National Water Summary Wetland Resources: HIGHLIGHTS 13 South Carolina__________________________________ Nearly one-quarter of South Carolina is wetland about 4.6 million acres. South Carolina's wetlands provide flood attenuation, erosion control, water-quality maintenance, recreational opportunities, and fish and wildlife habitat. South Carolina wetlands are important wintering areas for migratory waterfowl on the Atlantic Fly way. Wetlands in the State include wet pine flatwoods, pocosins, Carolina bays, beaver ponds, bottom-land forests, swamps, fresh and salt marshes, and tidal flats. About 80 percent of the wetlands are freshwater and forested. Wetland acreage in South Carolina has declined by more than one-quarter since the late 1700's, primarily as a result of human activities. South Dakota __________________________________ Wetlands occupy about 1.8 million acres (3.6 percent) of South Dakota. These wetlands are of great economic and esthetic value because they provide important habitat for wildlife (especially migratory waterfowl), hydrologic benefits that include water retention and flood attenuation, and numerous recreational opportunities. By far the most common wetland type in South Dakota is the prairie pothole, which occurs in glaciated eastern South Dakota. Wetland area in South Dakota has decreased by about 35 percent during the last 200 years from about 2.7 million to about 1.8 million acres. Agricultural conversions, notably in the prairie pothole region, have accounted for most wetland losses. Tennessee____________________________________ Estimates of Tennessee's wetland area range from 640,000 to 1,400,000 acres. Although wetlands constitute a small percentage of Tennessee, they are ecologically and economically valuable to the State. Bottom-land forests are the most common Tennessee wetlands; they are most abundant in the flood plains of rivers in the western part of the State. Nearly three-fifths of Tennessee's original wetlands have been lost; major causes of loss or degradation in Tennessee have included agricultural conversions, logging, reservoir construction, channelization, sedimentation, and urbanization. The Tennessee Wetlands Acquisition Act of 1986 autho- rizes the acquisition of wetlands by use of real estate transfer taxes. Texas_______________________________________ Wetlands cover about 7.6 million acres of Texas, 4.4 percent of the State's area. The most extensive wetlands are the bottom-land hardwood forests and swamps of East Texas; the marshes, swamps, and tidal flats of the coast; and the playa lakes of the High Plains. Wetlands provide flood attenuation, bank stabilization, water- quality maintenance, fish and wildlife habitat, and opportunities for hunting, fishing, and other recreational activities. Commercial fisheries benefit directly from coastal wetlands. Texas has lost about one-half of its original wetlands as a result of agricultural conversions, overgrazing, urbanization, channelization, water- table declines, construction of navigation canals, and other causes. Utah_______________________________________ Wetlands cover only a small part of Utah but provide critical aquatic habitat in an arid environment as well as economic and other benefits. Utah wetlands include the shallows of small lakes, reservoirs, ponds, and streams; riparian wetlands; marshes and wet meadows; mud and salt flats; and playas. The largest wetlands in the State surround Great Salt Lake. Because of the importance of Great Salt Lake and its associated wet- lands to migratory waterfowl and shorebirds, in 1991 the lake was designated a Hemispheric Reserve in the Western Hemisphere Shorebird Reserve Network. Streamflow regulation and agricultural, residential, industrial, and ski-area development have resulted in widespread wetland losses. Vermont_____________________________________ Estimates of the area covered by wetlands in Vermont range from 4 to 6 percent of the State's total area. The largest wetlands are in the valleys of the northeast and in river flood plains and deltas in the Lake Champlain Valley. Vermont's wetlands provide flood and erosion control, water-quality maintenance, timber, and recreational opportunities. As much as 35 percent of Vermont's wetlands have been lost; major causes have been conversion to agriculture and residential and recreational development. The State is undertaking the Vermont Wetlands Conservation Strategy, a comprehensive review of current wetland conservation programs that will recommend actions to improve wetland conservation in Vermont. U.S. Virgin Islands_________________________________ Wetlands in the U.S. Virgin Islands comprise about 3 percent of the land surface. Wetlands are habitat for fish, shellfish, and birds, including endangered species such as the peregrine falcon and brown pelican. Fresh- water is scarce in the islands, and wetlands there are mainly estuarine and marine types such as salt ponds, mangrove forests, sea grass beds, and coral reefs. Shoreline wetlands are vulnerable to destruction from construction of tourist facilities and water-dependent developments like marinas and to degradation by sedi- mentation and septic tank leachate. The Territorial Legislature adopted the Indigenous and Endangered Spe- cies Act of 1990, which establishes a policy of "no net loss of wetlands" to the maximum extent possible. 14 National Water Summary Wetland Resources: HIGHLIGHTS Virginia. Virginia has about 1 million acres of wetlands; one-quarter are tidal and three-quarters are nontidal. Forested wetlands (swamps) are the most common wetlands in the State. Both shores of the Chesapeake Bay have extensive estuarine wetlands. Conversion to nonwetland uses (agricultural, urban, industrial, and recreational), channelization and ditching, and other causes have resulted in the loss of about 42 percent of Virginia's wetlands since the 1780's. Development in wetlands is regulated in part by means of the Virginia Water Protection Permit. Local governments may adopt prescribed zoning ordinances and form citizen wetland boards to regulate their own tidal wetlands; the State retains an oversight and appellate role. Washington___________________________________ Wetlands cover only about 2 percent (939,000 acres) of Washington, but they benefit the State both ecologi- cally and economically. Wetlands are nursery and feeding areas for anadromous fish such as salmon and steelhead trout. About 75 percent of the State's wetlands contain freshwater and include forested and shrub swamps, bogs, fens, marshes, wet prairies and meadows, vernal pools, and playas. About 25 percent are estuarine or marine and include marshes, tidal flats, beaches, and rocky shores. Estimates of wetland loss in Washington range from 20 to 50 percent; causes of loss or degradation include agricultural conversion, urban expansion, siting of ports and industries, logging, and invasion of nonnative plants and animals. West Virginia__________________________________ Wetlands constitute less than 1 percent of West Virginia's surface area but contribute significantly to the State's economic development and ecological diversity. Common West Virginia wetlands include swamps, peat bogs, marl wetlands, marshes, wet meadows, and ponds. The Canaan Valley and Meadow River wetlands together contain about 14 percent of the State's wetlands. The Canaan Valley wetland complex is the largest in the central Appalachian Mountains. West Virginia has lost about one-fourth of its original wetlands; primary causes have been agricultural conversions, channelization, pond and reservoir construction, and urbaniza- tion. Some wetlands have been created as a result of beaver activity. Western Pacific Islands_____________________________ Most of the wetlands in the Mariana, Samoan, Caroline, and Marshall Islands (referred to as the Western Pacific Islands in this report) are in coastal areas. Wetlands on the islands include mangrove swamps, marshes, and coral reefs. Wetlands are of economic importance on many islands because the staple food, taro, is grown in converted or constructed wetlands. On the larger islands, wetlands are important wildlife habitat. Avail- able trend information indicates that on many islands there has been wetland loss or degradation due to agricultural conversion, urban expansion, or firewood cutting. Wetland activities on islands under United States jurisdiction are subject to Federal regulation. Wisconsin______________________________________ Wetlands cover more than 5 million acres (15 percent) of Wisconsin. Common wetlands include swamps and marshes in southern Wisconsin and peatlands in northern Wisconsin. Wetlands are most numerous in glaciated parts of the State; the unglaciated "driftless" section of southwestern Wisconsin has few wetlands, except in stream valleys filled with unconsolidated outwash and alluvium. Wetland acreage has decreased by nearly one-half over the last 200 years, primarily owing to agricultural development. In 1991 the State became the first to adopt water-quality standards for wetlands; the standards allow the State to control wet- land development under section 401 of the Clean Water Act. Wyoming______________________________________ Wetlands cover about 1.25 million acres (2 percent) of Wyoming and are the most diverse ecosystems in the State's semiarid environment. The Laramie Plain Lakes wetland complex is home to the Wyoming toad, an endangered species. Trend information indicates that wetland acreage in Wyoming has decreased over time, primarily due to agricultural and urban development. However, agricultural diversions, whose original pur- pose was to flush salts and increase hay-meadow production, have enhanced wetlands along the Bear River; the Bear River wetland is one of the most productive and diverse bird habitats in Wyoming. The Wyoming Wetlands Act is the basis for wetland program development by the State. U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources: INTRODUCTION 15 Introduction This volume, National Water Summary on Wetland Resources, is organized into two parts, a somewhat different format than the seven previous volumes (see inside front cover for previous volumes) in the National Water Summary series. (The "Hydrologic Conditions and Water-Related Events" included in the previous volumes are published separately, as U.S. Geological Survey Open- File Reports Numbers 96-107 and 96-145.) This volume is the result of a coordinated effort to compile the most up-to-date information available on wetland resources. Although much has been written about the biological aspects of wetlands, much less has been written about the hydrology and the non-habitat functions of wetlands. This volume presents an overview of wetland resources from many different perspectives. The first part of this volume, "Overview of Wetland Resources," discusses wetland resources from a national perspective and provides background information for the State summaries section. This section contains articles on the technical, management and research, and restoration, creation, and recovery aspects of wetland resources. These articles relate the history of wetlands in the United States; the definition of wetlands and a description of the U.S. Fish and Wildlife Service Classification System (Cowardin and others, 1979); hydrologic and water-quality factors that affect the distribution of wetlands and related functions commonly attributed to wetlands; the role of wetlands as habitat for birds; the roles of Federal agencies in wetland protection legislation and research; progress in inventory and mapping of wetlands; techniques for evaluating wetlands; human attempts to restore damaged wetlands and create new ones; and the recovery of wetlands following natural disasters. The second part, "State Summaries of Wetland Resources," describes wetlands of each State, the District of Columbia (combined with Maryland), Puerto Rico, the U.S. Virgin Islands, and the Western Pacific Islands. Each State summary discusses wetlands in terms of value, types and distribution, hydrologic setting, and trends in acreage from predevelopment to modern times. Each State summary also provides an overview of public- and private-sector wetland-conservation efforts in that State and a table showing the wetland-related responsibilities of principal government agencies and private organizations within the State. Illustrations include a map depicting the areal distribution of principal wetlands and selected related features such as ecoregions, physiography, precipitation, runoff, evaporation, or other physical or climatic features that influence the presence or distribution of wetlands in that State. Some of the State summaries include a map or cross section depicting the hydrologic setting of wetlands and (or) a map showing predevelopment wetland distribution. To supplement the information provided in this volume, bibliographic references are listed at the end of each article and State summary. An extensive list of suggested references for more information about topics discussed in the "Overview of Wetland Resources" is available in U.S. Geological Survey Open-File Report 96-169. This report also is available online at http:// h2o.usgs.gov/public/nwsum/bib/bihhtml. Most technical terms are defined in the glossary at the end of this Horicon Marsh, Wisconsin, provides volume, and a conversion table of water measurements recreational opportunities. (Photograph by precedes the glossary. Philtip}. Redman, U.S. Geological Survey.) 16 National Water Summary Wetland Resources: INTRODUCTION Acknowledgments Preparation of the National Water Summary requires compiling information from many individuals within the U.S. Geological Survey and various Federal and State agencies. The National Water Summary on Wetland Resources is the eighth in this series of U.S. Geological Survey Water-Supply Papers and it was prepared under the direction of Robert M. Hirsch, Chief Hydrologist. The report compilers gratefully acknowledge the assistance of water-resources agencies in each State in preparing and reviewing the State summaries of wetland resources. In addition, the following Federal agencies and other organizations contributed articles for this report: ManTech Environmental Technology, Incorporated U.S. Department Of Defense Army Corps Of Engineers U.S. Department Of the Interior Fish And Wildlife Service National Biological Service U.S. Environmental Protection Agency University Of Texas In addition, the following Federal agencies and other organizations provided materials for this report: American Indian Resources Institute National Aeronautics and Space Administration U.S. Department of Commerce National Oceanic and Atmospheric Administration U.S. Department of the Interior National Park Service Although individual acknowledgment of all reviewers, managers, illustrators, and typists who partici- pated in the preparation of this report is not feasible, their cooperation and many contributions made this report possible. The following persons, however, deserve special mention: The authors of the individual articles and the State summaries, who adhered to strict guidelines and whose names appear on the articles; David W. Moody and Richard W. Paulson, who had the vision for this report, made the contacts, and got it started; Virginia Carter, who provided technical guidance and reviewed every article; Katherine Walton-Day, Martha A. Hayes, Helen M. Light, Melanie R. Darst, and Benjamin F. McPherson, who prepared prototype State summaries, and D. Briane Adams, and Marcus C. Waldron, who helped coordinate the effort; Kenneth J. Lanfear, who provided managerial assistance; Jo Ann Macy, who provided managerial assistance and editorial review; Jack H. Green and Chester Zenone, who provided tech- nical editorial review; Edith B. Chase, Elizabeth A. Ciganovich, and Mary A. Kidd, who provided editorial review and editorial assistance; Hyla Strickland, who provided editorial review and editorial assistance in the preparation of the State summaries; John M. Watson, who provided editorial review of the State summa- ries; and Susan Tufts-Moore, who provided editorial review for several Overview articles; Patricia S. Greene, Robert J. Olmstead, and Gregory J. Allord, who assisted with the design, coordination, and layout of the report and its illustrations; James O. Whitmer, Gina P. Barker, Timothy D. Covington, John M. Watermolen, Joel J. Skalet, and Alan M. Duran, who assisted with the graphics; Jamaica Pettit, who did typesetting and layout for the State summaries; Kimberley L. Fry, who provided general assistance with review and prepa- ration of articles in the front part (Introduction and Overview sections) of the book; Helen F. Ipsaro and vol- unteer Judy G. Fry, who proofread the front-part articles; volunteers Katie Green, Joyce Ipsaro, and Uma Rao, who helped keep us organized. References Cited Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Classification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FGWS/OBS-79/31, 131 p. Fry, K.L., comp., 1996, Supplemental reference list for the National Water Summary on Wetland Resources: U.S. Geological Survey Open-File Report, No. 96-169, 39 p. McCabe, G.J., Crowe, Michael, Brown, W.O., and Fretwell, J.D., 1996, Hydrologic conditions and water-related events Water Year 1992: U.S. Geological Survey Open-File Report No. 96-107, 1 sheet. McCabe, G.J., Crowe, Michael, Brown, W.O., Fretwell, J.D., and Fry, K.L., 1996, Hydrologic conditions and water-related events Water Year 1993: U.S. Geological Survey Open-File Report, No. 96-145, 1 sheet. U.S. Geological Survey Water-Supply Paper 2425 Overview of Wetland Resources A restored wetland near Blackfoot River, Montana. (Photograph by Kenneth I. Lanfear, U.S. Geological Survey.) 17 Overview of Wetland Resources Technical aspects of wetlands History of wetlands in the conterminous United States Thomas E. Dahl and Gregory]. Allord......................................... 19 Wetland definitions and classifications in the United States Ralph W. Tiner............................................................................ 27 Wetland hydrology, water quality, and associated functions Virginia Carter............................................................................. 35 Wetlands as bird habitat Robert E. Stewart, jr. .................................................................... 49 Wetland management and research Wetland protection legislation Todd H. Votteler and Thomas A. Muir ........................................ 57 Wetland research by Federal agencies Richard E. Coleman, Edward T. LaRoe, and Russell F. Theriot..... 65 Wetland mapping and inventory Bill O. Wilen, Virginia Carter, and}. Ronald Jones...................... 73 Wetland functions, values, and assessment Richard P. Novitzki, R. Daniel Smith, and Judy D. Fretwell......... 79 Restoration, creation, and recovery of wetlands Wetland restoration and creation Mary E. Kentula........................................................................... 87 Effects of Hurricane Andrew (1992) on wetlands in southern Florida and Louisiana John K. Lovelace and Benjamin J. McPherson ............................. 93 Effects of the Great Midwest Flood of 1993 on wetlands James R. Kolva ............................................................................ 97 18 National Water Summary Wetland Resources: TECHNICAL ASPECTS 19 Technical Aspects of Wetlands History of Wetlands in the Conterminous United States By Thomas E. Dahl 1 and Gregory J. Allord2 At the time of European settlement in the early 1600's, the area that was to become the conterminous United States had approximately 221 million acres of wetlands. About 103 million acres remained as of the mid-1980's (Dahl and Johnson, 1991). Six States lost 85 percent or more of their original wetland acreage twenty-two lost 50 percent or more (Dahl, 1990) (fig. 2). Even today, all of the effects of these losses might not be fully realized. Historical events, technological innovations, and values of society sometimes had destructive effects on wetlands. By examining the historical backdrop of why things happened, when they happened, and the consequences of what happened, society can better appreciate the importance of wetlands in water-re- source issues. Society's views about wetlands have changed considerably especially in the last half century. Interest in the preservation of wetlands has increased as the value of wetlands to society has be- come more fully understood. From a cultural stand- point, it is interesting to understand how changes in opinions and values came about, and what effects these changes had on wetland resources. From an eco- logical perspective, it is important to understand how the loss of wetlands affects fish, wildlife, and the environment as a whole. EARLY 1600'S TO 1800 COLONIAL SETTLEMENT Wetland drainage began with permanent settle- ment of Colonial America. Throughout the 1600's and ]700's, colonization was encouraged by European monarchs to establish footholds in North America. The effects of this colonization on the landscape be- came obvious in the early to mid-1700's. Much of our knowledge of early wetlands comes from maps and other documents that survived over time. The origins of settlers influenced both where people settled and how they mapped and used natu- ral resources. Few records exist because the original English, French, and Spanish settlements were estab- lished before the land was surveyed. Settlements in the North tended to be clustered, whereas communi- ties in the South were more widely scattered because of the predominance of agriculture. Many different land surveying systems resulted in an incomplete patchwork of ownership that ultimately caused many legal problems due to boundary errors and overlap- ping claims (Garrett, 1988). It was not until 1785 that the Land Ordinance Act established the United States Public Land Survey, which required surveying and partitioning of land prior to settlement. Although not Interest in the preservation of wetlands has increased as the value of wetlands has become more fully understood. EXPLANATION Percent of wetlands lost, 1780'sto mid-1980's | | Less than 50 | | 50-85 (16 States) | | More than 85 (6 States) 500 KILOMETERS THE EVERGLADES Figure 2. States with notable wetland loss, 1780's to mid-1980's. (Source: Modified from Dahl, 1990.) 1 U.S. Fish and Wildlife Service. 2 U.S. Geological Survey. 20 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Great Dismal Swamp 100 MILES __I 100 KILOMETERS The original extent of wetland acreage and the effect of widespread drainage is evident in Washington County, N.C. Originally, wetlands covered over 186,000 acres or about 85 percent of the land area of Washington County. Large-scale drainage began as early as 1788 with the construction of a canal 6 miles long and 20 feet wide to drain the wetlands north and east of Phelps Lake (Washington County Historical Society, 1979). A system of cross ditches leading into the main canal was designed to drain up to 100,000 acres of wetlands so that rice and corn could be grown (Tant, 1981). Today, about 34 percent of Washington County's original wetland acreage remains in scattered tracts. Figure 3. Extent of wetlands in Washington County, N. C, circa 1780 (left) and 1990 (right). (Source: U.S. Fish and Wildlife Service, Status and Trends, unpub. data, 1994.) Technical advances facilitated wetland conversion. Oil-powered dredge digging a 30-foot-wide ditch to drain wetlands nearCarroll, Iowa. (Photograph courtesy of National Archives, 8-D-2214-2570.) established to provide information on natural re- sources, surveys do provide some information about the distribution and location of wetlands. During the 1700's, wetlands were regarded as swampy lands that bred diseases, restricted overland travel, impeded the production of food and fiber, and generally were not useful for frontier survival. Set- tlers, commercial interests, and governments agreed that wetlands presented obstacles to development, and that wetlands should be eliminated and the land re- claimed for other purposes. Most pioneers viewed natural resources from wetlands as things to be used without limit (Tebeau, 1980). The most productive tracts of land in fertile river valleys in parts of Vir- ginia had been claimed and occupied before 1700. The resulting shortage of choice land stimulated colo- nists to move south to the rich bottom lands along the Chowan River and Albemarle Sound of North Carolina on the flat Atlan- tic coastal plain. Initially, settlements con- sisted primarily of shelters and subsistence farms on small tracts of land. To extend the productive value of available land, wetlands on these small tracts were drained by small hand-dug ditches. During the mid- to late 1700's, as the population grew, land clear- ing and farming for profit began to affect larger tracts of land; many coastal plain wet- lands were converted to farmland (fig. 3). Once drained, these areas provided produc- tive agricultural lands for growing cash crops. Widespread wetland drainage was most prevalent in the southern colonies. In 1754, South Carolina authorized the drainage of Cacaw Swamp for agricultural use (Beau- champ, 1987). Similarly, areas of the Great Dismal Swamp in Virginia and North Caro- lina were surveyed in 1763 so that land could be re- claimed for water transportation routes. Farming on large plantations was common practice in the South and necessitated some drainage or manipulation of wetlands. By the 1780's, immigrants had settled along the fertile river valleys of the Northeast and as far south as present-day Georgia. Wetlands in these river val- leys suffered losses with this settlement (fig. 4). Small towns and farms were established in the valleys along the rivers of Massachusetts, Connecticut, New York, and Pennsylvania. Settlement extended to the valleys beyond the Appalachian Mountains in Virginia and followed the major rivers inland through the Caroli- nasby 1800. Figure 4. States with notable wetland loss, early 1600's to 1800. 1800 TO 1860 WESTWARD EXPANSION The period between 1800 and 1860 was a time of growth in the United States. During these decades, numerous land acquisitions the Louisiana Purchase (1803); Florida and eastern Louisiana ceded by Spain (1819); annexation of Texas (1845); the Oregon Com- National Water Summary Wetland Resources: TECHNICAL ASPECTS 21 Red River Basin (1818) Claimed area- became part of State of Maine (1842) Gadsden Purchase (1853) Florida Cession (1819) Claimed area- became part of State of Louisiana (1812) Figure 5. Major United States land acquisitions between 1800 and 1860. (Source: U.S. Geological Survey, 1970.) promise (1846); and lands ceded from Mexico (1848) greatly expanded the land area of the United States (Garrett, 1988) (fig. 5). With this land expan- sion, the population grew from 7.2 million in 1810 to 12.8 million in 1830 (U.S. Bureau of the Census, 1832). Land speculation increased with this rapid growth and marked a period when land and resources seemed to be available for the taking. It was a time of rapid inland movement of settlers westward into the wetland-rich areas of the Ohio and Mississippi River Valleys (fig. 2). Large-scale conversion of wetlands to farmlands started to have a real effect on the dis- tribution and abundance of wetlands in the United States. Areas where notable wetland loss occurred be- tween 1800 and 1860 are shown in figure 6. Figure 6. States with notable wetland loss, 1800 to 1860. Technical advances throughout the 1800's greatly facilitated wetland conversions. The opening of the Erie Canal in 1825 provided settlers with an alterna- tive mode and route of travel from New York to the Great Lakes States, increasing migration of farmers to the Midwest. The canal also provided low-cost transportation of timber and agricultural products from the Nation's interior to eastern markets and sea- ports (McNall, 1952). Another innovation, the steam- powered dredge, allowed the channelizing or clear- ing of small waterways at the expense of adjacent wet- lands. Between 1810 and 1840, new agricultural implements plows, rakes, and cultivators enabled settlers to break ground previously not considered for farming (McManis, 1964). Mechanical reapers intro- duced in the 1830's stimulated competition in, and furthered refinements of, farm equipment marketed in the Midwest (Ross, 1956). These inno- vations ultimately took a toll on wetlands as more land was drained, cleared, and plowed for farming. Wetland drainage continued. In the Midwest, the drainage of the Lake Erie marshes of Michigan and Ohio probably started about 1836. Cotton and tobacco farming continued to flourish in the South- ern States and precipitated the additional drainage of thousands of acres of wetlands for conversion to cropland. Wetlands also were being modified in other ways. The Horicon Marsh in Wiscon- sin was dammed and flooded in 1846 for a transportation route and to provide com- mercial fishing. Toward the middle of the century, lumbering was an important in- dustry in the Midwest, supplying wood for construction and fuel for stoves and fire- places. Much of the Nation's timber came from the swamp forests of Ohio, Indiana, and Illinois, which typically contained a mix of birch, ash, elm, oak, cot- tonwood, poplar, maple, basswood, and hickory. In 1849, Congress passed the first of the Swamp Land Acts, which granted all swamp and overflow lands in Louisiana to the State for reclamation. In 1850, the Act was made applicable to 12 other States, and in 1860, it was extended to include lands in two additional States (Shaw and Fredine, 1956) (table 1). Although most States did not begin immediate large- scale reclamation projects, this legislation clearly set the tone that the Federal Government promoted wet- land drainage and reclamation for settlement and de- velopment. This tone pervaded policy and land-use trends for the next century. 1860 TO 1900 AGRICULTURE MOVES WEST The American Civil War (1861-65) affected wet- lands because traversing swamps and marshes with heavy equipment presented major logistical problems for both armies. The design, engineering, and con- struction of transportation and communication net- works were stimulated. Attention became focused on the development of routes around, through, or over water bodies and wetlands, and on production of ac- curate maps (fig. 7). These maps provided an early glimpse of some of the Nation's wetlands. After the war, the Nation's attention focused on westward expansion and settlement. Railroads were important in the initial development of transportation routes. The railroads not only opened new lands, in- cluding wetlands, to development, but the railroad in- dustry also was a direct consumer of wetland forest products. In the 1860's, more than 30,000 miles of railroad track existed in the United States (Stover, 1961). The railroads of Ohio consumed 1 million cords of wood annually just for fuel (Gordon, 1969). The additional quantity of wood used for ties is not known. From 1859 to 1885, intense timber cutting and land clearing eliminated many of Ohio's wetlands, including the Black Swamp (fig. 8). The Black Swamp was in the northwestern cor- ner of Ohio and was a barrier to travel and settlement. Table 1 . Acreage granted to the States under the authority of the Swamp Land Acts of 1849, 1850, and 1860 YEAR 1849 1850 1860 STATE Louisiana Alabama Arkansas California Florida Illinois Indiana Iowa Michigan Mississippi Missouri Ohio Wisconsin Minnesota Oregon ACRES 9,493,456 441,289 7,686,575 2,192,875 20,325,013 1,460,164 1,259,231 1,196,392 5,680,310 3,347,860 3,432,481 26,372 3,360,786 4,706,503 286,108 TOTAL 64,895/415 22 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Figure 7. Confederate States of America map of Southeastern United States with wetlands depicted for strategic rather than natural resources value. (Source: National Archives, Record Croup 94, Civil War Atlas, Plate CXLIV.) This forested wetland was estimated to have been 120 miles long and 40 miles wide, covering an area nearly equal in size to Connecticut (Gordon, 1969; Ohio De- partment of Natural Resources, 1988). The swamp, which was an elm-ash forested wetland typical of the region, contained a variety of commercially valuable trees (Eyre, 1980). Nothing was left of the Black Swamp by the end of the nineteenth century. During the mid- to late 1880's, agriculture ex- panded rapidly westward along the major river sys- tems. Several regions of abundant wetlands lay di- rectly in the path of this expansion (Woolen and Jones, 1955), including: The prairie pothole wetlands of western Minne- sota, northern Iowa, and North and South Dakota The bottom lands of Missouri and Arkansas in the lower Mississippi River alluvial plain The delta wetlands of Mississippi and Louisiana The gulf plains of Texas By the 1860's, settlers started to farm and drain the prairie pothole region. At first, only a modest number of potholes were drained. By the late 1800's, however, the numbers had increased significantly. As new kinds of machinery increased the ability to till more land, the conversion of wetlands to farm- lands increased rapidly. Huge wheat farms, or "Bo- nanza Farms," were operating in the Dakota Territory (present-day North and South Dakota) by 1875. New mechanical seeders, harrowers, binders, and thresh- ers, designed specifically for wheat production, were used to cultivate large tracts of land for these farms (Knue, 1988). Many wetlands were lost as a result of these operations. Improvements in drainage technology greatly affected wetland losses in the East and the Midwest. As the use of steam power expanded, replacing hand labor for digging ditches and manufacturing drainage tiles, the production and installation of drainage tiles increased rapidly. By 1880, 1,140 factories located mainly in Illinois, Indiana, and Ohio manufactured drainage tiles that were used to drain wetlands for farming (Pavelis, 1987). By 1882, more than 30,000 miles of tile drains were operating in Indiana alone. By 1884, Ohio had 20,000 miles of public ditches de- signed to drain 11 million acres of land (Wooten and Jones, 1955). Wetland conversion in the Central Valley of Cali- fornia began in the mid-1800's, when farmers began diking and draining the flood-plain areas of the val- ley for cultivation (fig. 9). Other States had notable losses of wetlands between 1860 and 1900 (fig. 10). 1900 TO 1950 CHANGING TECHNOLOGY The first half of the twentieth century was a time of ambitious engineering and drainage operations. Two World Wars, a rapidly growing population, and industrial growth fueled the demand for land as in- dustry and agriculture propelled the United States to the status of a world leader. Technology was increas- ingly important in manipulation of the Nation's water resources. Two of the most notable projects that affected wetlands were California's Central Valley Project and the lock and dam system on the Missis- sippi River. Although draining had begun one-half century earlier, wetland modification in the Central Valley accelerated early in the 20th century. By the 1920's, about 70 percent of the original wetland acreage had been modified by levees, drainage, and water-diver- sion projects (Frayer and others, 1989). In the 1930's, 0 200 MILES 0 200 KILOMETERS Black Swar *O=r--Cf*fe"V | -yh--Jtardiji Coujitr -i -;U-r 0 50 MILES 0 50 KILOMETERS ', .rH «amp ! I - +, A..J d ta*_,-lrH^ HISTORIC WETLANDS Black Swamp Pickaway Plains 1 1 _ I > Scioto Marsh 1_ r _ L/ Other marshes, Hardin County f / 0 ' / Hog Creek Mareh L> r 1 j Cranberry Marsh A Ji / Lake Erie Marshes -T TV Dougan's Prairie AREA IN ACRES 3,072,000 4,800 16,000 9,000 8,000 1,000 300,000 Unknown TOTAL 3,410,800 DATE DRAINED 1859-1885 1821 1859,1883 1860's 1868-1874 Unknown 1936-1974 1827 SOURCE Ohio Dept. Nat. Res., 1988 Gordon, 1969 Gordon, 1969 Howe, 1900 Gordon, 1969 Gordon, 1969 Bednarik, 1984 Middleton, 1917 Figure 8. Location, estimated original acreage, and drainage date of Ohio's historic wetlands. National Water Summary Wetland Resources: TECHNICAL ASPECTS 23 AREA OF INTEREST Originally the Central Valley of California was very different than it is now. Tulare Lake held water in a basin with a surface area approximately four times the surface area of Lake Tahoe. Buena Vista and Kern Lakes also held water as runoff accumulated from the Sierra Nevada. The rivers and streams that flowed into the Central Valley were lined with bottom-land forests com- posed of willow, sycamore, oak, elder, poplar, and alder; lush stands of wet- land grasses and tules dominated the valley floors and prairies (Hundley, 1992). Prior to the mid-1800's, about 4 million 7 of the 13 million acres that made up California's Central \_ Valley were estimated to be _-J wetland. 200 KILOMETERS Figure 9. Wetlands of the Central Valley of California, circa 1820 (left) and 1990 (right). (Source: U.S. Fish and Wildlife Service, Status and Trends, unpub. data, 1994.) large-scale flood-control projects, diversion dams, and water-control structures were being built on the tributary rivers entering the valley. Wetland modification also continued farther east. Before the installation of the lock and dam system in 1924, the bottom lands of the Mississippi River cor- ridor were primarily wooded islands separated by deep sloughs (Green, 1984). Hundreds of small lakes and ponds were scattered throughout extensive wooded areas. The river channel was subject to shift- ing sands and shallows, and changed constantly. Lake and dam structures were built to create a permanent navigable waterway. The water depth increased be- hind each dam to create a pool that extended upstream to the next dam. The first pool was filled in 1935 and the system was completed when the last pool was filled in 1959. The resulting changes to the river sys- tem eliminated large water-level fluctuations and helped stabilize water depth and flooding. Bottom lands no longer dried out in summer, and former hay meadows and wooded areas were converted to marsh- lands surrounding the pools. One type of wetland was PRAIRIE POTHOLE WETLANDS Figure 10. States with notable wetland loss, 1860 to 1900. exchanged for another. Although some pools of the Upper Mississippi River have problems with silt depo- sition and restricted water circulation, these "created" wetland areas provide habitat for fur-bearing animals, waterfowl, and fish. In other parts of the country, this era was marked by urban and agricultural expansion projects that drained both large and small wetlands. Some of the most ambitious projects were attempts to drain and cultivate Horicon Marsh in Wisconsin in 1904; com- mercial timber harvesting in southern Georgia, which began in 1908 as a precursor to attempts to drain the Okefenokee Swamp (Trowell, 1988); and in 1914, the draining of North Carolina's largest natural lake, Lake Mattamuskeet, to create farmland (U.S. Fish and Wildlife Service, undated). Early in the century, land developers dug drainage ditches in an attempt to drain a huge area for development in the vast peatlands north of Red Lake, Minn. (Glaser, 1987). On July 29, 1917, the Minneapolis Sunday Tribune ran a full page advertisement to attract homesteaders to the Red Lake area "perhaps the last of the unsettled, uncut tim- berland in the middle of the country" (Wright, 1984). By 1930, nearly all of the prairie wetlands in Iowa, the southern counties of Minnesota, and the Red River Valley in North Dakota and Minnesota were drained (Schrader, 1955). Attempts were underway to drain and farm large parts of The Everglades (a huge expanse of wetlands in southern Florida). By the I9301s, more than 400 miles of drainage canals were already in place (Lord, 1993). (See article "Wetland Resources of Florida" in the State Summaries section of this volume.) With the passage of the Sugar Act of 1934, additional wet- lands in southern Florida were drained and put into sugarcane production. Sugarcane yields more than doubled from410,000 to 873,000 tons between 1931 and 1941 (Clarke, 1977), largely at the expense of Drainage tile operation, circa 1940's. Tiles provide a conduit for moving water from a wetland. (Photo- graph courtesy of U.S. Department of Agriculture.) 24 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES The Migratory Bird Hunting Stamp Act was one of the first pieces of legislation to initiate the process of acquiring and restoring America's wetlands. wetland acreage. Severe flooding in southern Florida in the 1920's and again in the 1940*s prompted the U.S. Army Corps of Engineers to build the Central and Southern Florida Project for flood control. This massive undertaking, which required levees, water- storage areas, channel improvements, and large pumps, caused additional large modification to The Everglades' environment (Light and Dineen, 1994). Mechanized farm tractors had replaced horses and mules for farm labor during this half century. The tractors could be used more effectively than animals for drainage operations, and the old pasture land then became available for improvement and production of additional crops. In the Midwest and the North-cen- tral States, the use of tractors probably contributed to the loss of millions of acres of small wetlands and prairie potholes. In the 1930's, the U.S. Government, in essence, provided free engineering services to farmers to drain wetlands; and by the 1940's, the Government shared the cost of drainage projects (Burwell and Sugden, 1964). Organized drainage districts throughout the country coordinated efforts to remove surface water from wetlands (Wooten and Jones, 1955). Figure 11 shows areas of notable wetland losses between 1900 and 1950. Figure 11. States with notable wetland loss, 1900 to 1950. In 1934, in stark contrast to these drainage ac- tivities, Congress passed the Migratory Bird Hunt- ing Stamp Act. This Act was one of the first pieces of legislation to initiate the process of acquiring and re- storing America's wetlands. 1950 TO PRESENT CHANCING PRIORITIES AND VALUES By the 1960's, most political, financial, and in- stitutional incentives to drain or destroy wetlands were in place. The Federal Government encouraged land drainage and wetland destruction through a variety of legislative and policy instruments. For example, the Watershed Protection and Flood Pre- vention Act (1954) directly and indirectly increased the drainage of wetlands near flood-control projects (Erickson and others, 1979). The Federal Government directly subsidized or facilitated wetland losses through its many public-works projects, technical practices, and cost-shared drainage programs admin- istered by the U.S. Department of Agriculture (Erickson, 1979). Tile and open-ditch drainage were considered conservation practices under the Agricul- ture Conservation Program whose policies caused wetland losses averaging 550,000 acres each year from the mid-1950's to the mid-1970's (Office of Tech- nology Assessment, 1984). Agriculture was respon- sible for more than 80 percent of these losses (Frayer and others, 1983). Figure 12 shows States with no- table wetland losses between 1950 and 1990. Figure 12. States with notable wetland loss, 1950 to 1990. Since the 1970's, there has been increasing awareness that wetlands are valuable areas that pro- vide important environmental functions. Public awareness of, and education about, wetlands has in- creased dramatically since the early 1950's. Federal policies, such as the "Swampbuster," have eliminated incentives and other mechanisms that have made the destruction of wetlands technically and economically feasible. New laws, such as the Emergency Wetland Resources Act of 1986, also curtail wetland losses. (See article "Wetland Protection Legislation" in this volume for information on legislation affecting wet- lands.) Some of the more ambitious drainage projects of earlier years have been abandoned. Now, places like Lake Mattamuskeet, Horicon Marsh, and the Okefenokee Swamp, which once were targeted for drainage, have become National Wildlife Refuges that provide wetland habitat for a variety of plants and ani- mals. The effects of the Federal policy reversal on the rate of wetland loss are not clear. Estimates indicate that wetland losses in the conterminous United States from the mid-1970's to the mid-1980's were about 290,000 acres per year (Dahl and Johnson, 1991). This is about one-half of the losses that occurred each year in the 1950's and '60's. The preceding numbers do not include degraded or modified wetlands. Al- though the estimate above reflects a declining rate of loss, land development continues to destroy wetlands. From about 1987 to the present, Federal efforts to restore wetlands have increased. Although there is no precise number for all of the wetland acres re- stored, the U.S. Fish and Wildlife Service (1991) es- timated that between 1987 and 1990 about 90,000 acres were added to the Nation's wetland inventory. Attempts are underway now to restore some of The Everglades. The remaining Everglades comprise about 2,300 square miles, three-fifths of which is impounded in managed water-conservation areas (Lord, 1993). This wetland system currently is expe- riencing mercury contamination and other water- quality problems, water-supply and diversion contro- versies, declining wildlife populations, increasing pressure from tourism, urban and agricultural expan- sion, and influx of nuisance plants. National Water Summary Wetland Resources: TECHNICAL ASPECTS 25 The magnitude of environmental alter- ations in Florida, with numerous conflict- ing interests, exemplifies the dilemma of managing water resources and wetlands. What initially seemed to be a matter of water removal turned into an extremely complex and costly issue involving water- use objectives at all levels of government (Tebeau, 1980). Today there are more than 100 dams within the California Central Valley drain- age basins and thousands of miles of water-delivery canals. Water is diverted for irrigation, hydroelectric power, and munici- pal and industrial water supplies. Only 14 percent of the original wetland acreage re- mains. The Tulare Lake Basin has been virtually drained, leaving only remnant wetland areas and a dry lakebed, and Buena Vista and Kern Lakes rarely contain water (fig- 9). Currently (1994), manipulation of water levels in wetlands rather than the complete removal of water as in the past, is a trend that affects wetlands. Partial drainage or lowering of the water levels to allow for certain uses is becoming preva- lent in some parts of the country. Effects of this type of management are uncertain. EXAMPLE OF CHANGING ATTITUDES HORICON MARSH The history of the Horicon Marsh in Wisconsin is an example of how people's at- titudes toward wetlands have changed through time (fig. 13). Horicon Marsh was dammed, flooded, and renamed Lake Horicon in 1846. At that time, it was the largest manmade lake in the world (about 4 miles wide by 14 miles long) (Wisconsin Department of Natural Resources, 1990). Lake Horicon was used for commercial transportation and for commercial fishing. In 1869, the dam was removed and the land returned to marsh. In 1883, two sportsmen's clubs, which leased the marsh area, reported that 500,000 ducks hatched an- nually in the marsh. They also reported that 30,000 muskrats and mink were trapped in the southern half of the marsh. Huge flocks of geese also were reported (Freeman, 1948). In 1904, attempts were made to drain the marsh and sell the reclaimed land for truck farms. Lawsuits resulting from inadequate drainage halted the reclamation effort. In 1921, local conservationists began efforts to protect Horicon Marsh as a game refuge, and the State of Wisconsin created the Horicon Marsh Wildlife Ref- uge in July 1927. Later, to avoid legal confrontations with the local farmers, the State bought property and (or) water rights to the southern half of the refuge and the Federal Government purchased rights to the northern half. In 1990, Horicon Marsh was added to the sites recognized by the Convention on Wetlands of International Importance especially as Waterfowl Habitat. Horicon Marsh 1846 Horicon Lake 1853 Horicon Swamp 1881 Horicon Wildlife Refuge 1984 Figure 13. Horicon Marsh, Wis., evolved from original marsh (1846), to lake (1853), to swamp (1881), to wildlife refuge (1984). (Source: Sequence is left to right, top to bottom, Historical Society of Wisconsin negative number WHi (X3) 50111, WHi (X3) 50212, WHi (X3) 50113; U.S. Geological Survey, 1984.) Estimates indicate that today slightly more than 100 million acres of wetlands remain in the conter- minous United States. Although the rate of wetland conversion has slowed in recent years, wetland losses continue to outdistance wetland gains. References Cited Beauchamp, K.H., 1987, A history of drainage and drain- age methods, in Pavelis, G.A., ed., Farm drainage in the United States History, status, and prospects: Washington, D.C., Economic Research Service, U.S. Department of Agriculture, Miscellaneous Publication no. 1455, p. 13-29. Bednarik, K.E., 1984, Saga of the Lake Erie marshes, in Hawkins, A.S., Hanson, R.C., Nelson, H.K., and Reeves, H.M., eds., Flyways Pioneering waterfowl management in North America: Washington, D.C., U.S. Fish and Wildlife Service, p. 423^430. Burwell, R.W., and Sugden, L.G., 1964, Potholes Going, going..., in Linduska, J.P., ed., Waterfowl tomorrow: Washington, D.C., U.S. Fish and Wildlife Service, p. 369-380. 26 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Clarke, M.J., 1977, An economic and environmental assess- ment of the Florida Everglades sugarcane industry: Bal- timore, Md., Johns Hopkins University, 140 p. Dahl, T.E., 1990, Wetlands Losses in the United States, 1780's to 1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 13 p. Dahl, T.E., and Johnson, C.E., 1991, Wetlands Status and trends in the conterminous United States, mid-1970's to mid-1980's: Washington, D.C., U.S. Fish and Wild- life Service, 22 p. Erickson, R.E., 1979, Federal programs influencing wet- lands, Seventh Annual Michigan Landuse Policy Con- ference: East Lansing, Midi., Michigan State Univer- sity, 246 p. Erickson, R.E., Under, R.L., and Harmon, K.W., 1979, Stream channelization (p.l. 83-566) increased wetland losses in the Dakotas: Wildlife Society Bulletin, v. 7, no. 2, p. 71-78. Eyre, F.H., 1980, Forest cover types of the United States and Canada: Washington, D.C., Society of American For- esters, 148 p. Prayer, WE., Monahan, T.J., Bowden, D.C., and Graybill, F.A., 1983, Status and trends of wetlands and deepwater habitats in the conterminous United States, 1950's to 1970's: Fort Collins, Colo., Colorado State University, 31 p. Prayer, WE., Peters, D.D., and Pywell, H.R., 1989, Wetlands of the California Central Valley Status and Trends 1939 to mid 1980's: Portland, Oreg., U.S. Fish and Wildlife Service, 28 p. Freeman, A.E., and Bussewitz, W.R., 1948, History of Horicon: Horicon, Wis., undated, 126 p. Garrett, WE., ed., 1988, Historical atlas of the United States: Washington, D.C., National Geographic Society, 289 p. Glaser, P.H., 1987, The ecology of patterned boreal peatlands of northern Minnesota A community pro- file: U.S. Fish and Wildlife Service, Report 85 (7.14), 98 p. Gordon, R.B., 1969, The natural vegetation of Ohio in pio- neer days: Columbus, Ohio, Bulletin of the Ohio Biologi- cal Survey, v. Ill, no. 2, Ohio State University, 113 p. Green, W.E., 1984, The great river refuge, in Hawkins, A.S., Hanson, R.C., Nelson, H.K., and Reeves, H.M., eds., Fly ways Pioneering waterfowl management in North America: Washington, D.C., U.S. Fish and Wildlife Service, p. 431^439. Howe, Henry, 1900, Historical collections of Ohio: Cincin- nati, Ohio, Ohio centennial edition, Published by the State of Ohio, v. 1, p. 881. Hundley, Norris, Jr., 1992, The great thirst Californians and water, 1700's-1990's: Berkeley, Calif., University of California Press, 551 p. Knue, Joseph, 1988, Of time and prairie 100 years of people and wildlife in North Dakota Observations in change: Bismarck, N. Dak., North Dakota State Game and Fish Department, 106 p. Light, S.S., and Dineen, J.W., 1994, Water control in The Everglades A historical perspective, in Davis, S.M., and Ogden, J.C., eds., Everglades The ecosystem and its restoration: Delray Beach, Fla., St. Lucie Press, p. 47-84. Lord, L.A., 1993, Guide to Florida environmental issues and information: Winter Park, Fla., Florida Conservation Foundation, 364 p. McManis, D.R., 1964, The initial evaluation and utilization of the Illinois prairies, 1815-1840: Chicago, 111., Uni- versity of Chicago, Department of Geography Research Paper no. 94, 109 p. McNall, N.A., 1952, An agricultural history of the Genesee Valley, 1790-1860: Philadelphia, Pa., University of Pennsylvania Press, 276 p. Middleton, E.P., 1917, History of Champaign County, Ohio, its people, industries and institutions: Indianapolis, Ind., B.E. Bowen and Co., Inc., 116 p. Office of Technology Assessment, 1984, Wetlands Their use and regulation: Washington, D.C., U.S. Congress, OTA-0-206, 208 p. Ohio Department of Natural Resources, 1988, Ohio wet- lands priority conservation plan An addendum to the 1986 Ohio statewide comprehensive outdoor recreation plan: Office of Outdoor Recreation Services, 67 p. Pavelis, G.A., ed., 1987, Farm drainage in the United States History, status, and prospects: Economic Research Service, U.S. Department of Agriculture, Miscellaneous Pub. No. 1455, 170 p. Ross, E.D., 1956, Retardation in farm technology before the power age: Agricultural History 30, p. 11-18. Schrader, T.A., 1955, Waterfowl and the potholes of the north central states, in The yearbook of agriculture 1955: Washington, D.C., U.S. Department of Agricul- ture, 84th Congress, 1st Session, House Document no. 32, p. 596-604. Shaw, S.P., and Fredine, C.G., 1956, Wetlands of the United States Their extent and their value to waterfowl and other wildlife: Washington, D.C., U.S. Fish and Wild- life Service Circular 39, 67 p. Stover, J.F., 1961, American railroads: Chicago, 111., Uni- versity of Chicago Press, 310 p. Tant, PL., 1981, Soil survey of Washington County, North Carolina: Washington, D.C., U.S. Soil Conservation Service, 99 p. Tebeau, C.W., 1980, Ahistory of Florida: Coral Gables, Fla., University of Miami Press, 527 p. Trowell, C.T., 1988, Exploring the Okefenokee Roland M. Harper in the Okefenokee Swamp, 1902 and 1919: Douglas, Ga., North Georgia College, Research Paper no. 2, 89 p. U.S. Bureau of the Census, 1832, Return of the whole num- ber of persons within the several districts of the U.S., 1830: Washington, D.C. U.S. Fish and Wildlife Service, 1991, United States Depart- ment of the Interior budget justification Fiscal year 1992: Washington, D.C., 121 p. ____Undated, Mattamuskeet National Wildlife Refuge: Swan Quarter, N.C., (Brochure). U.S. Geological Survey, 1984, Wisconsin State base map: U.S. Geological Survey, scale 1:500,000. Washington County Historical Society, 1979, Historic Wash- ington County: Plymouth, N.C., 31 p. Wisconsin Department of Natural Resources, 1990, Wet- lands/wonderlands Wisconsin natural resources: Madison, Wis., Wisconsin Department of Natural Resources, 16 p. Wooten, H.H., and Jones, L.A., 1955, The history of our drainage enterprises, in The yearbook of agriculture, 1955: Washington, D.C., U.S. Department of Agricul- ture, 84th Congress, 1st Session, House Document no. 32, p. 478^198. Wright, H.E., Jr., 1984, Red Lake peatland Its past and patterns: Minneapolis, Minn., University of Minnesota, James Ford Bell Museum of Natural History, v. 1, 7 p. FOR ADDITIONAL INFORMATION: Thomas E. Dahl, National Wetlands Inventory, 9720 Executive Center Drive, Suite 101 - Monroe Building, St. Petersburg, FL 33702; Gregory J. Allord, U.S. Geological Survey, 505 Science Drive, Madison, WI 53711 U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources: TECHNICAL ASPECTS 27 Technical Aspects of Wetlands Wetland Definitions and Classifications in the United States By Ralph W. Tiner 1 "Wetland" is a generic term for all the different kinds of wet habitats implying that it is land that is wet for some period of time, but not necessarily permanently wet. Wetlands have numerous definitions and classifications in the United States as a result of their diversity, the need for their inventory, and the regulation of their uses. This article provides an overview of wetland defi- nitions and classification systems of major wetland types in the United States. It also introduces the U.S. Fish and Wildlife Service (FWS) classification sys- tem (Cowardin and others, 1979) that is used throughout this volume. Wetlands typically occur in topographic settings where surface water collects and (or) ground water discharges, making the area wet for extended periods of time. Examples of some of these topographic settings, and some common names for wetland types associated with them are: Depressions (swales, sloughs, prairie potholes, Carolina bays, playas, ver- nal pools, oxbows, and glacial kettles) Relatively flat depositional areas that are subject to flooding (intertidal flats and marshes, coastal lowlands, sheltered embayments, shorelines, deltas, and flood plains) Broad, flat areas that lack drainage outlets (interstream divides and per- mafrost muskegs) Sloping terrain associated with springs, seeps, and drainageways; and rela- tively flat or sloping areas adjacent to bogs and subject to expansion by accumulation of peat Open water bodies (floating mats and submersed beds) Cross sections of some typical wetland landscapes and the position of the wet- land relative to specific topographic features are shown in figure 14. All areas considered to be wetlands must have enough water at some time during the year to stress plants and animals that are not adapted to life in wa- ter or saturated soils. A variety of wetland plant communities and soil types have developed in the United States because of regional differences in hydro- logic regimes, climate, soil-forming processes, and geologic settings. Conse- quently, many terms, such as "marsh," "bog," "fen," "swamp," "pocosin," "pothole," "playa," "salina," "vernal pool," "bottom-land hardwood swamp," "river bottom," "lowland," and others are applied to different types of wet- lands across the country. WETLAND DEFINITIONS Wetlands have been defined for specific purposes, such as research stud- ies, general habitat classification, natural resource inventories, and environ- mental regulations. Before the beginning of wetland-protection laws in the 1960's, wetlands were broadly defined by scientists working in specialized fields (Lefor and Kennard, 1977). A botanist's definition would emphasize plants; a soil scientist would focus on soil properties; and a hydrologist's defi- nition would emphasize fluctuations of the water table. Nonregulatory Definition The FWS developed a nonregulatory, technical definition that could have several uses, ranging from wetland protection to scientific investigations. This definition emphasizes three important attributes of wetlands: (1) hydrology the degree of flooding or soil saturation; (2) vegetation plants adapted to grow in water or in a soil or substrate that is occasionally oxygen deficient due to saturation (hydrophytes); and (3) soils those saturated long enough during the growing season to produce oxygen-deficient conditions in the upper part of the soil, which commonly includes the major part of the root zone of plants (hydric soils) (Cowardin and others, 1979; Tiner, 1991). To supplement this Isolated depressions Sheltered embayments flood plains Relatively flat interstream divides (including pocosins) Figure 14. Cross sections of selected wetland landscapes showing typical positions of wetlands relative to topographic features. U.S. Fish and Wildlife Service. 28 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Seepage areas and springs Basins with streams Blanket bogs in boreal and arctic regions Open water bodies with floating mats and submersed beds Figure 14. Cross sections of selected wetland landscapes showing typical positions of wetlands relative to topographic features. Continued. definition and to help identify wetlands in the United States, the FWS pre- pared a list of wetland plants (Reed, 1988). In addition, the Soil Conserva- tion Service 1 (SCS) developed a list of hydric soils (U.S. Soil Conservation Service, 1991). On the basis of plant and soil conditions, wetlands typically fall into one of three categories: (1) areas with hydrophytes and hydric soils (marshes, swamps, and bogs); (2) areas without soils but with hydrophytes (aquatic beds and seaweed-covered rocky shores); and (3) areas without soil and without hydrophytes (gravel beaches and tidal flats) that are periodically flooded. The FWS definition generally does not include permanent deep- water areas as wetlands. However, permanent shallow waters that commonly support aquatic beds and emergent plants (erect, rooted, nonwoody plants that are mostly above water) are classified as wetlands. Regulatory Definitions as Compared to Nonregulatory Definitions In the 1960's and 1970's, State and Federal environmental laws gave some protection to wetlands. On the basis of different interests to be protected, however, each governing body developed a different definition of wetlands. Examples of some of these definitions are given in table 2. Only wet soils vegetated with hydrophytes are considered as wetlands by the three Federal agencies involved with regulation the SCS, the U.S. Environmental Pro- tection Agency (EPA), and the U.S. Army Corps of Engineers (Corps). The FWS uses a nonregulatory definition that is broader and includes aquatic beds in shallow freshwater and naturally nonvegetated areas. In the context of veg- etated wetlands, all four agency definitions are conceptually the same in that they include hydrology, vegetation, and soils. Most States have developed regulatory definitions to protect certain wet- lands from exploitation. Therefore, State definitions are much broader than any of the Federal definitions. The State definitions tend to emphasize the presence of certain plants for identification purposes (table 2). However, the States did not produce a comprehensive list of "wetland plant species," making it difficult to use vegetation consistently to identify the limits of wet- lands (Tiner, 1989 and 1993a). WETLAND CLASSIFICATION "Wetland classification," as used in this article, refers to the designa- tion of different wetland types on the basis of hydrology, vegetation, and soils. The Federal Government's early attempts to classify wetlands were motivated largely by agricultural interests that sought to convert wetlands to cropland. The first classification systems put wetlands into a few general categories on the basis of location river swamps, lake swamps, and upland swamps (Wright, 1907). Other classification systems were related to the degree of inundation permanent swamps, wet grazing land, periodically overflowed land, and periodically swampy land (Dachnowski, 1920). Later wetland classifications developed from a need to differentiate wet- lands from other land-cover types for regional and national planning purposes, or because of ecological interest. Martin and others (1953) developed a "Clas- sification of Wetlands in the United States " to serve as a framework for the 1954 national inventory to assess the amount and types of wetland water- fowl habitat. Although this system is still in use, the inadequate definition of wetland types has led to inconsistencies in application across the country (Cowardin and others, 1979). When the FWS began a review of existing wetland inventories in 1974, they found more than 50 classification schemes (U.S. Fish and Wildlife Ser- vice, 1976). The only one of these that was nationally based was that of Martin and others (1953). Subsequently, the FWS worked with several prominent wetland scientists and mapping experts to identify necessary elements for a new classification system based on the concept of ecosystems (Sather, 1976). Four key objectives were established: Identify ecologically similar habitat units Classify these units systematically to facilitate resource-management decisions Identify units for inventory and mapping purposes Provide uniformity in concept and terminology throughout the country The SCS became the Natural Resources Conservation Service in 1994, National Water Summary Wetland Resources: TECHNICAL ASPECTS 29 Table 2. Examples of wetland definitions used by Federal and State agencies in the United States Organization (reference) Wetland definition FEDERAL U.S. Fish and Wildlife Service (Cowardin and others, 1979} U.S. Army Corps of Engineers {33 CFR 328.3) U.S. Environmental Protection Agency {40 CFR 230.3) U.S. Soil Conservation Service (National Food Security Act Manual 1988) (The Act is commonly known as the "Swampbuster") STATE Connecticut (CT General Statutes, Sections 22a-36 to 45, inclusive, 1972,1987} Connecticut (CT General Statutes, Sections 22a-28 to 35, inclusive 1969) Rhode Island Coastal Resources Management Council (Rl Coastal Resources Management Program as amended June 28,1983) Rhode Island Department of Environmental Management {Rl General Law, Sections 2-1-18 etseq.) New Jersey (Pinelands Protection Act, NJ. STAT. ANN. Section 13:18-1 to 13:29.) New Jersey (Coastal Wetland Protection Act - NJ. STAT. ANN. Section 13:18-1 to 13:9A-10) Massachusetts (MA General Law Chapter 131, Section 40) "Wetlands are lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water. For the purposes of this classification wetlands must have one or more of the following three attributes: (1} at least periodically, the land supports predominantly hydrophytes; (2) the substrate is predominantly undrained hydric soil; and (3) the substrate is nonsoil and is saturated with water or covered by shallow water at some time during the growing season of each year." "Wetlands are those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas." "Wetlands are defined as areas that have a predominance of hydric soils and that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and under normal circumstances do support, a prevalence of hydrophytic vegetation typically adapted for life in saturated soil conditions, except lands in Alaska identified as having high potential for agricultural development and a predominance of permafrost soils." "Wetlands mean land, including submerged land which consists of any of the soil types designated as poorly drained, very poorly drained, alluvial, and floodplain by the National Cooperative Soils Survey, as may be amended from time to time, by the Soil Conservation Service of the United States Department of Agriculture. Watercourses are defined as rivers, streams, brooks, waterways, lakes, ponds, marshes, swamps, bogs, and all other bodies of water, natural or artificial, public or private." "Wetlands are those areas which border on or lie beneath tidal waters, such as, but not limited to banks, bogs, salt marshes, swamps, meadows, flats or other low lands subject to tidal action, including those areas now or formerly connected to tidal waters, and whose surface is at or below an elevation of one foot above local extreme high water." (Also includes a list of plants capable of growing in tidal wetlands.) "Coastal wetlands include salt marshes and freshwater or brackish wetlands contiguous to salt marshes. Areas of open water within coastal wetlands are considered a part of the wetland. Salt marshes are areas regularly inundated by salt water through either natural or artificial water courses and where one or more of the following species predominate:" (8 indicator plants listed}. "Contiguous and associated freshwater or brackish marshes are those where one or more of the following species predominate:" (9 indicator plants listed). Fresh water wetlands are defined to include, "but not be limited to marshes; swamps; bogs; ponds; river and stream flood plains and banks; areas subject to flooding or storm flowage; emergent and submergent plant communities in any body of fresh water including rivers and streams and that area of land within fifty feet (50') of the edge of any bog, marsh, swamp, or pond." Various wetland types are further defined on the basis of hydrology and indicator plants, including bog (15 types of indicator plants), marsh (21 types of indicator plants), and swamp (24 types of indicator plants plus marsh plants). "Wetlands are those lands which are inundated or saturated by water at a magnitude, duration and frequency sufficient to support the growth of hydrophytes. Wetlands include lands with poorly drained or very poorly drained soils as designated by the National Cooperative Soils Survey of the Soil Conservation Service of the United States Department of Agriculture. Wetlands include coastal wetlands and inland wetlands, including submerged lands." "Coastal wetlands are banks, low-lying marshes, meadows, flats, and other lowlands subject to tidal inundation which support or are capable of supporting one or more of the following plants:" (29 plants are listed). "Inland wetlands" are defined as including, but not limited to, Atlantic white cedar swamps (15 plants listed), hardwood swamps (19 plants specified), pitch pine lowlands (10 plants listed), bogs (12 plants identified), inland marshes (6 groups of plants listed), lakes and ponds, and rivers and streams. "Coastal wetlands" are "any bank, marsh, swamp, meadow, flat or other low land subject to tidal action in the Delaware Bay and Delaware River, Raritan Bay, Sandy Hook Bay, Shrewsbury River including Navesink River, Shark River, and the coastal inland waterways extending southerly from Manasquan Inlet to Cape May Harbor, or at any inlet, estuary, or those areas now or formerly connected to tidal areas whose surface is at or below an elevation of 1 foot above local extreme high water, and upon which may grow or is capable of growing some, but not necessarily all, of the following:" (19 plants are listed.) Coastal wetlands exclude "any land or real property subject to the jurisdiction of the Hackensack Meadowlands Development Commission...." "The term 'freshwater wetlands' shall mean wet meadows, marshes, swamps, bogs, areas where groundwater, flowing or standing surface water or ice provides a significant part of the supporting substrate for a plant community for at least five months of the year; emergent and submergent plant communities in inland waters; that portion of any bank which touches any inland waters." Various wetland types are further defined on the basis of hydrology and indicator plants and include bogs {19 types of indicator plants), swamps (22 types of plants), wet meadows (12 types of plants), and marshes (22 types of indicator plants). 30 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES System Marine Subsystem -Subtidal Intertidal -Estuarine- -Subtidal Intertidal -Riverine -Tidal Lower Perennial -Upper Perennial -Intermittent -Lacustrine -Limnetic (deepwater habitat only] -Littoral -Palustrine (wetlands only) Class Rock bottom Unconsolidated bottom Aquatic bed Reef Aquatic bed Reef Rocky shore Unconsolidated shore Rock bottom Unconsolidated bottom Aquatic bed Reef Aquatic bed Reef Streambed Rocky shore Unconsolidated shore Emergent wetland Scrub-shrub wetland Forested wetland Rock bottom Unconsolidated bottom Aquatic bed Streambed Rocky shore Unconsolidated shore Emergent wetland Rock bottom Unconsolidated bottom Aquatic bed Rocky shore Unconsolidated shore Emergent wetland Rock bottom Unconsolidated bottom Aquatic bed Rocky shore Unconsolidated shore Streambed Rock bottom Unconsolidated bottom Aquatic bed Rock bottom Unconsolidated bottom Aquatic bed Rocky shore Unconsolidated shore Emergent wetland Rock bottom Unconsolidated bottom Aquatic bed Unconsolidated shore Moss-lichen wetland Emergent wetland Scrub-shrub wetland Forested wetland Figure 15. Classification hierarchy of wetlands and deepwater habitats showing systems, subsystems, and classes. (Source: Coward!n and others, 1979). On the basis of these objectives, the FWS devel- oped a new wetland classification system. The sys- tem was extensively field tested and reviewed by pub- lic and private sectors before being published as "Classification of Wetlands and Deepwater Habitats of the United States" (Cowardin and others, 1979). Since its publication, the system has become the na- tional and international standard for identifying and classifying wetlands (Mader, 1991; Gopal and others, 1982). THE U.S. FISH AND WILDLIFE SERVICE WETLAND CLASSIFICATION SYSTEM A synopsis of the FWS wetland classification system is presented here. Each of the State summa- ries in this volume gives a general summary of the system, and a more comprehensive discussion can be found in Cowardin and others (1979). The system de- scribed here proceeds from general to specific, as shown in figure 15. System. Each system represents "a complex of wetlands and deepwater habitats, that share the influ- ence of similar hydrologic, geomorphologic, chemi- cal, or biological factors" (Cowardin and others, 1979, p. 4). Five systems are defined: Marine open ocean and its associated coastline Estuarine tidal waters of coastal rivers and empayments, salty tidal marshes, mangrove swamps, and tidal flats Riverine rivers and streams Lacustrine lakes, reservoirs, and large ponds Palustrine marshes, wet meadows, fens, playas, potholes, pocosins, bogs, swamps, and small shallow ponds The overwhelming majority of the Nation's wet- lands fall within the Palustrine System; most of the remaining wetlands are in the Estuarine System. Subsystem. Each system, except the Palustrine, is divided into subsystems (fig. 15). The Marine and Estuarine Systems have two subsystems that are de- fined by tidal water levels: subtidal continuously submersed areas; and intertidal alternately flooded and exposed to air. The Lacustrine System has two subsystems that are defined by water depth: littoral the shallow-water zone where wetlands extend from the lakeshore to a depth of 6.6 feet below low water or to the extent of nonpersistent emergent plants such as arrowheads, pickerelweed, wild rice, or bulrush, if they grow beyond that depth; and limnetic the deepwater zone where low water is deeper than 6,6 feet (deepwater habitat). The Riverine System has four subsystems that represent different reaches of a flowing freshwater system: tidal water levels sub- ject to tidal fluctuations; lower perennial perma- nent, slow-flowing waters having a well-developed flood plain; upper perennial permanent, fast-flow- ing waters having very little or no flood plain; and in- termittent streambeds with flowing water for only part of the year. Classes. Each subsystem is divided into classes, which describe the general appearance of the wetland or deepwater habitat in terms of the domi- nant vegetative form, or composition of the substrate (table 3). For areas where vegetation covers 30 per- cent or more of the surface, five vegetative classes are National Water Summary Wetland Resources: TECHNICAL ASPECTS 31 Table 3. Classes and subclasses of wetlands and deepwater habitats as defined by Cowardin and others (1979) Class Brief description Subclasses Rock bottom Generally permanently flooded areas with bottom sub- Bedrock; rubble strates consisting of at least 75 percent stones and boulders and less than 30 percent vegetative cover. Unconsolidated bottom Generally permanently flooded areas with bottom sub- Cobble-gravel; sand; strates consisting of at least 25 percent particles smaller mud; organic than stones and less than 30 percent vegetative cover. Aquatic bed Generally permanently flooded areas that are veg- etated by plants growing principally on or below the water surface. Algal; aquatic; rooted vascular; floating vascular Reef Characterized by elevations above the surrounding substrate and interference with normal wave flow; they are primarily subtidal. Coral; mollusk; worm Stream bed Channel whose bottom is completely dewatered at low water periods. Bedrock; rubble; cobble-gravel; sand; mud; organic; vegetated Rocky shore Wetlands characterized by bedrock stones or boulder with areal coverage of 75 percent or more and with less than 30 percent coverage by vegetation. Bedrock; rubble Unconsolidated shore Wetlands having Unconsolidated substrates with less than 75 percent coverage by stones, boulders, and bed- rock and less than 30 percent native vegetative cover. Cobble-gravel; sand; mud; organic; vegetated Moss-lichen wetland Wetlands dominated by mosses or lichens where other plants have less than 30 percent coverage. Moss; lichen Emergent wetland Wetlands dominated by erect rooted, herbaceous hy- drophytes. Persistent; nonpersistent Scrub-shrub wetland Wetlands dominated by woody vegetation less than 20 feet {6 meters) tall. Deciduous; evergreen; dead woody plants Forested wetland Wetlands dominated by woody vegetation 20 feet (6 meters) or taller. Deciduous; evergreen; dead woody plants used aquatic bed, moss-lichen wetland, emergent wetland, scrub-shrub wetland, and forested wetland. Aquatic beds may be either wetlands or deepwater habitats, depending on water depth. Six other classes are used where vegetation gen- erally is absent and where substrate and degree of flooding are distinguishing features rock bottom, Unconsolidated bottom, reef, streambed, rocky shore, and Unconsolidated shore. Areas that are nonvegetated and permanently flooded are classed as either rock bottom or Unconsolidated bottom. Areas that are pe- riodically flooded are classed as streambed, rocky shore, or Unconsolidated shore. Reefs are found in both permanently flooded (deepwater habitats) and periodically flooded tidal areas (wetlands). Subclass. Each class is divided further into subclasses (table 3) to define the substrate in non-veg- etated areas or the dominant vegetation in vegetated areas. In vegetated areas, the subclasses are persis- tent or nonpersistent emergents, mosses and lichens, or broad-leaved deciduous, needle-leaved deciduous, broad-leaved evergreen, needle-leaved evergreen, and dead woody plants. In nonvegetated areas the sub- classes are bedrock, rubble, cobble-gravel, mud, sand, and organic. Dominance Type. Below the subclass, domi- nance type can be applied to specify the dominant plant or animal in the wetland. This level allows one to distinguish between distinct plant communities (red maple forested wetland and pin oak forested wet- land, or a tussock-sedge-dominated emergent wetland and cattail-dominated emergent wetland). In this way, individual wetlands can be grouped in ecologically similar units. Modifiers. The classification system also uses modifiers to describe hydrologic, chemical, and soil characteristics, and the effects of humans on the wet- lands. The four specific modifiers used are water re- gime, water chemistry, soil, and special. These modi- fiers can be applied to classes, subclasses, and domi- nance types. The water-regime modifiers describe flooding or soil saturation and are divided into two main groups tidal and nontidal. Tidal modifiers can be subdivided into two general categories salt- and brackish-water and freshwater. The nontidal modi- fier inland freshwater and saline defines condi- tions where runoff, ground-water discharge or re- charge, evapotranspiration, wind, and lake seiches (oscillation of the water) cause water-level changes. Both tidal and nontidal modifiers are briefly defined in table 4. Water-chemistry modifiers are divided into two categories: salinity and pH. The salinity modifiers have been further divided into two groups: haline for estuarine and marine tidal areas dominated by sodium chloride and saline for nontidal areas dominated by salts other than sodium chloride. The salinity and The FWS classification system has become the national and international standard for identifying and classifying wetlands. 32 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Table 4. Water regime modifiers as defined by Cowardin and others (1979) Group Tidal Water type _ Salt-and brackish- water areas Freshwater Nontidal Inland fresh- water and saline areas Water regime and definition Subtidal Permanently flooded tidal waters Irregularly exposed Exposed less often than daily by tides Regularly flooded Daily tidal flooding and exposure to air Irregularly flooded Flooded less often than daily and typically exposed to air Permanently flooded Permanently flooded by tides and river overflow but with tidal fluctuation in water levels Semipermanently flooded Flooded most of the growing season by river overflow but with tidal fluctuation in water levels Regularly flooded Daily tidal flooding and exposure to air Seasonally flooded Flooded irregularly by tides and river overflow Temporarily flooded Flooded irregularly by tides and for brief periods during growing season by river overflow Permanently flooded Flooded throughout the year in all years Intermittently exposed Flooded year-round except during extreme droughts Semipermanently flooded Flooded throughout the growing season in most years Seasonally flooded Flooded for extended periods in the growing season, but surface water is usually absent by the end of the growing season Saturated Surface water is seldom present, but the substrate is saturated to the surface for most of the growing season Temporarily flooded Flooded for only brief periods during the growing season, with the water table usually well below the soil surface for most of the season Intermittently flooded The substrate is usually exposed and only flooded for variable periods without detectable seasonal periodicity (may be upland in some situations) Artificially flooded Duration and amount of flooding is controlled by pumps or siphons in combination with dikes or dams The FWS wetland classification system has provided a uniformity of wetland terminology. fluctuations in salinity of water in a wetland and the type of salt causing the salinity determines what plant and animal species the wetland can support. The pH modifiers identify waters that are acid (pH less than 5.5), circumneutral (pH 5.5-7.4), and alkaline (pH greater than 7.4). Soil modifiers are divided into two categories organic and mineral. In general, if a soil has 20 per- cent or more organic matter by weight in the upper 16 inches, it is considered an organic soil. If it has less than this amount, it is a mineral soil. Special modifiers are used to describe human or beaver activities. These modifiers are: excavated, im- pounded (obstruct outflow of water), diked (obstruct inflow of water), partly drained, farmed, and artifi- cial (materials deposited by humans to create or modify a wetland). Although an extensive treatment of wetlands is beyond the scope of this article, it would be incom- plete without examples of the classification of some of the different wetland types. In figure 16, some of the major wetland types are listed by their common names and then classified by the FWS system. The variety of wetlands and their locations also are illus- trated. For further information on wetland types, see Mitsch and Gosselink (1986), Niering (1984), Tiner (1984, 1987, 1993b), and Wilen and Tiner (1993). CONCLUSIONS The FWS wetland classification system places ecologically similar habitats into a hierarchal system that permits wetland classification down to domi- nance types, which are based on dominant plants or substrates. The system can be used to identify units for inventory and mapping for Federal and State wet- land inventories. It also has provided a uniformity of wetland terminology. The FWS uses this classifica- tion to determine wetland status and trends infor- mation useful to resource managers and planners at all levels of government. Since the 1954 inventory by the FWS, wetlands have changed because of natural and human-related activities. Wetland characteristics and values have become better defined, more widely known, and more appreciated. As a result, Federal and State leg- islation has been passed to protect wetlands, and some States have completed wetland surveys (Cowardin and others, 1979) to aid in protecting and managing this resource. National Water Summary Wetland Resources: TECHNICAL ASPECTS 33 EXPLANATION Number General wetland type 1 2 3 4 5 6 7 8 9 10 11 12 13 Willow swamp Cattail marsh Inland lakeshore marsh Floating bog Salt marsh Maple-ash swamp Brackish marsh Cypress-gum swamp Pocosin Cottonwood riparian forest Wet meadow Black spruce bog Prairie pothole Location Alaska Range east of Paxon, Alaska Near Brainerd, Minn. Lake Durant, N.Y. Adirondacks, N.Y. Nantucket, Mass. Sussex County, NJ. Cedar Key, Fla. Francis Marion National Forest, S.C. Francis Marion National Forest, S.C. Near Reno, IMev. Nisqually, Wash. Juneau, Alaska Devil's Lake area, N. Dak. System Palustrine Palustrine Lacustrine Palustrine Estuarine Palustrine Estuarine Palustrine Palustrine Palustrine Palustrine Palustrine Palustrine Subsystem Class Scrub-shrub Emergent Littoral Emergent Scrub-shrub Intertidal Emergent Forested Intertidal Emergent Forested Scrub-shrub Forested Emergent Forested Emergent Subclass Broad-leaved deciduous Persistent Nonpersistent Broad-leaved evergreen Persistent Broad-leaved deciduous Persistent Needle/broad-leaved deciduous Broad-leaved evergreen Broad-leaved deciduous Persistent Needle-leaved evergreen Nonpersistent Water regime Seasonally flooded Seasonally flooded Permanently flooded Saturated Tidal, Irregularly flooded Seasonally flooded Tidal, Irregularly flooded Semipermanently flooded Saturated Temporarily flooded Season ally flooded Saturated Semipermanently flooded Figure 16. Examples of the classification for major wetland types in the United States, following Cowardin and others (1979). (Note that there are no subsystems for the Palustrine System. Photograph 1 by David Dahl; 4 by Bill Zinni; 12 by Jon Hail; all others by Ralph W. Tiner. AH photographers are with the U.S. Fish and Wildlife Service.) 34 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES References Cited Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Classification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Dachnowski, A.P., 1920, Peat deposits in the United States and their classification: Soil Science, v. 10, no. 6, p. 453^56. Gopal, Brij, Turner, R.E., Wetzel, R.G., and Whigham, D.F., 1982, Wetlands Ecology and management, in Pro- ceedings of the First International Wetlands Confer- ence, September 10-17,1980, New Delhi, India: Jaipur, India, National Institute of Ecology and International Scientific Publications, 514 p. Lefor, M.W., and Kennard, W.C., 1977, Inland wetland defi- nitions: Storrs, Conn., University of Connecticut., In- stitute of Resources, Report 28, 63 p. Mader, S.F., 1991, Forested wetlands classification and mapping A literature review: New York, N.Y., Na- tional Council of the Paper Industry for Air and Stream Improvement, Inc., Technical Bulletin no. 606, 99 p. Martin, A.C., Hotchkiss, Neil, Uhler, P.M., and Bourn, W.S., 1953, Classification of wetlands of the United States: Washington D.C., U.S. Fish and Wildlife Service Spe- cial Scientific Report, Wildlife, no. 20, 14 p. Mitsch, W.J., and Gosselink, J.G., 1986, Wetlands: New York, N.Y., Van Nostrand Reinhold Co., Inc., 539 p. Niering, W.A., 1984, Wetlands: New York, N.Y., Alfred A. Knopf, Inc., 638 p. Reed, P.B., Jr., 1988, National list of plant species that oc- cur in wetlands National summary: Washington, D.C., U.S. Fish and Wildlife Service Biological Report, v. 88, no. 24, 244 p. Sather, J.H., ed., 1976, National wetland classification and inventory workshop, July 20-23, 1975, College Park, Md., University of Maryland, Proceedings: Washington, D.C., U.S. Fish and Wildlife Service Report, 358 p. Tiner, R.W., 1984, Wetlands of the United States Current status and recent trends: Washington, D.C., U.S. Fish and Wildlife Service Report, 59 p. 1987. A field guide to coastal wetland plants of the northeastern United States: Amherst, Mass., University of Massachusetts Press, 285 p. 1989. Wetland boundary delineation, in Majumdar, S.K., Brooks, R.P., Brenner, F.J., and Tiner, R.W., Jr., eds., Wetlands ecology and conservation Emphasis in Pennsylvania: Easton, Pa., Pennsylvania Academy of Sciences, p. 231-248. 1991. The concept of a hydrophyte for wetland iden- tification: BioScience, v. 41, no. 4, p. 236-247. 1993a. Using plants as indicators of wetland: Phila- delphia, Pa., Academy of Natural Sciences of Philadel- phia, Proceedings, v. 144, p. 240-253. _1993b, Field guide to coastal wetland plants of the southeastern United States: Amherst, Mass., University of Massachusetts Press, 328 p. U.S. Fish and Wildlife Service, 1976, Existing state and local wetland surveys (1965-1975), v. II, Narrative: Washington, D.C., U.S. Fish and Wildlife Service, Office of Biological Services Report, 453 p. U.S. Soil Conservation Service, 1991, Hydric soils of the United States: Washington, D.C., in cooperation with the National Technical Committee for Hydric Soils, U.S. Department of Agriculture, Miscellaneous publi- cation 1491. Wilen, B.O., and Tiner, R.W, 1993, Wetlands of the United States, in Whigham, D.F., Dykyjova, Dagmar, and Hejny, Slavomil, eds., Wetlands of the world I: Dordrecht, Netherlands, Kluwer Academic Publishers, p. 515-636. Wright, J.O., 1907, Swamp and overflowed lands in the United States: Washington, D.C., U.S. Department of Agriculture, Office of Experiment Stations, Circular 76, 23 p. FOR ADDITIONAL INFORMATION: Ralph W Tiner, U.S. Fish and Wildlife Service, 300 Westgate Center Drive, Hadley, MA 01035 U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources: TECHNICAL ASPECTS 35 Technical Aspects of Wetlands Wetland Hydrology, Water Quality, and Associated Functions By Virginia Carter1 The formation, persistence, size, and function of wet- lands are controlled by hydrologic processes. Distribution and differences in wetland type, vegetative composition, and soil type are caused primarily by geology, topogra- phy, and climate. Differences also are the product of the movement of water through or within the wetland, water quality, and the degree of natural or human-induced dis- turbance. In turn, the wetland soils and vegetation alter water velocities, flow paths, and chemistry. The hydrologic and water-quality functions of wetlands, that is, the roles wetlands play in changing the quantity or quality of wa- ter moving through them, are related to the wetland's physi- cal setting. Wetlands are distributed unevenly throughout the United States because of differences in geology, climate, and source of water (fig. 17). They occur in widely diverse settings ranging from coastal margins, where tides and river discharge are the primary sources of water, to high mountain valleys where rain and snowmelt are the primary sources of water. Marine wetlands (those beaches and rocky shores that fringe the open ocean) are found in all coastal States. Estuarine wetlands (where tidal saltwater and inland freshwater meet and mix) are most plentiful in Alaska and along the southeastern Atlantic coast and the gulf coast. Alaska has the largest acreage of estuarine wetlands in the United States, followed by Florida and Louisiana. Inland (nontidal) wetlands are found in all States. Some States, such as West Virginia, have few large wet- lands, but contain many small wetlands associated with streams. Other States, such as Nebraska, the Dakotas, and Texas, contain many small isolated wetlands the lakes of the Nebraska Sandhills, the prairie potholes, and the playa lakes, respectively. Northern States such as Minnesota and Maine contain numerous wetlands with organic soils (peatlands), similar in origin and hydrologic and veg- <^vW $$itv <*?%&& ^"CK" V^SiL '?^' ::>,f ^ "'^s^-""^"'.'.':,. EXPLANATION Approximate distribution of large wetlands and deepwater habitats Predominantly wetland n Predominantly deepwater habitat High density of small wetlands Selected locations Great Dismal Swamp ® Albemarle-Pamlico Sound The Everglades Barataria Basin New Madrid ReelfootLake ® Glacial Lake Agassiz Peatland Nebraska Sandhills Great Salt Lake Copper River Delta Sleetmute Figure 17. Major wetland areas in the United States and location of sites mentioned in the text. (Source: Data from T.E. Dahl, U.S. F/sfc and Wildlife Service, unpub. data, 1991.) 1 U.S. Geological Survey. 36 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Typical prairie pothole wetland in North Dakota. (Photo- graph by Virginia Carter, U.S. Geological Survey.) Glacial Lake Agassiz peatland, Minnesota. (Photograph by Virginia Carter, U.S. Geological Survey.) etative characteristics to the classic bog and fen peat- lands of northern Europe. However, peatlands are by no means limited to Northern States they occur in the Southeastern and Midwestern United States wher- ever the hydrology and chemical environment are conducive to the accumulation of organic material. Wetlands occur on flood plains for example, the broad bottom-land hardwood forests and river swamps (forested wetlands) of southern rivers and many of the narrow riparian zones along streams in the Western United States. Wetlands are commonly associated with lakes or can occur as isolated features of the land- scape. They can form large complexes of open water and vegetation such as The Everglades of Florida, the Okefenokee Swamp of Georgia and Florida, the Copper River Delta of Alaska, and the Glacial Lake Agassiz peatland of Minnesota. HYDROLOCIC PROCESSES IN WETLANDS Hydrologic processes occurring in wetlands are the same processes that occur outside of wetlands and collectively are referred to as the hydrologic cycle. Major components of the hydrologic cycle are pre- cipitation, surface-water flow, ground-water flow, and evapotranspiration (ET). Wetlands and uplands con- tinually receive or lose water through exchange with the atmosphere, streams, and ground water. Both a fa- vorable geologic setting and an adequate and persis- tent supply of water are necessary for the existence of wetlands. The wetland water budget is the total of inflows and outflows of water from a wetland. The compo- nents of a budget are shown in the equation in figures 18 and 19. The relative importance of each compo- nent in maintaining wetlands varies both spatially and High water table sr Figure 18. Components of the wetland water budget. (P + SWI + GWI = ET + SWO + GWO + AS, where P is precipitation, SWI is surface-water inflow, SWO is surface-water outflow, CWI is ground- water inflow, GWO is ground-water outflow, ET is evapotranspiration, and AS is change in storage.) National Water Summary Wetland Resources: TECHNICAL ASPECTS 23 22/\ ETf 37 !cwo;>6 I/ Nevin Wetland, Wisconsin (Photograph by Richard P. Novitzki, ManTech Environmental Technology, Inc.) 100 Heron Pond, Alluvial Cypress Swamp, Illinois (Photograph by William ). Mitsch, Ohio State University) Okefenokee Swamp, Georgia Upland (Photograph by |ohn M. Hefner U.S. Fish and Wildlife Service) Swamp (Photograph by Virginia Carter U.S. Geological Survey) 26[GWI \ Arctic Fen, west of Baker Lake, Northwest Territories, Canada (Photograph by Nigel T. Roulet, McGill University, Montreal) >5C Hidden Valley Marsh, Ontario, Canada (Photograph by )tm Gehrels, Ontario Ministry of Environmental Energy) Figure 19. Water budgets for selected wetlands in the United Stales and Canada. (P + SWI + GWI = ET + SWO + CWO + AS, where P is precipitation, SWI is surface-water inflow, SWO is surface-water outflow, CWI is ground-water inflow, CWO is ground-water outflow, ET is evapotran spiral ion, and AS is change in storage. Components are expressed in percentages. Abbreviations used: < - less than; > = greater than.) (Sources from left to right and top to bottom: Novitzki, 1978; Roulet and Woo, 1986; Rykiel, 1984; Rykiel, 1984; Mitsch and Gosselink, 1993; and Gehrels and Muiamoottii, 1990.) 38 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Water budgets provide a basis for understanding hydrologic processes of a wetland. temporally, but all these components interact to cre- ate the hydrology of an individual wetland. The relative importance of each of the compo- nents of the hydrologic cycle differs from wetland to wetland (fig. 19). Isolated basin wetlands, typified by prairie potholes and playa lakes, receive direct pre- cipitation and some runoff from surrounding uplands, and sometimes receive ground-water inflow. They lose water to ET; some lose water that seeps to ground water, and some overflow during periods of excessive precipitation and runoff. These wetlands range from very wet to dry depending on seasonal and long-term climatic cycles. Wetlands on lake or river flood plains also receive direct precipitation and runoff and com- monly receive ground-water inflow. In addition, they can be flooded when lakes or rivers are high. Water drains back to the lake or river as floodwaters recede. Wet and dry cycles in these wetlands commonly are closely related to lake and river water-level fluctua- tions. Coastal wetlands, while also receiving direct precipitation, runoff, and ground-water inflow, are strongly influenced by tidal cycles. Peatlands with raised centers may receive only direct precipitation or may be affected by ground-water inflow also. Surface-water inflows affect only the edges of these wetlands. Determining water budgets for wetlands is impre- cise because as the climate varies from year to year so does the water balance. The accuracy of individual components depends on how well they can be mea- sured and the magnitude of the associated errors (Winter, 1981; Carter, 1986). However, water budgets, in conjunction with information on the local geology, provide a basis for understanding the hydrologic pro- cesses and water chemistry of a wetland, understand- ing its functions, and predicting the effects of natu- ral or human-induced hydrologic alterations. Each of the components is discussed below. Precipitation Precipitation is any form of water, such as rain, snow, sleet, hail, or mist, that falls from the atmo- sphere and reaches the ground. Precipitation provides water for wetlands directly and indirectly. Water is provided for a wetland directly when precipitation falls on the wetland or indirectly when precipitation falls outside the wetland and is transported to the wet- land by surface- or ground-water flow. For example, snow that falls on wetland basins provides surface- Figure 20. Percentage of transpiration and evaporation from various wetland components. (E, evaporation; T, transpiration.) water flow to wetlands during spring snowmelt. Snowmelt may also recharge ground water, sustain- ing ground-water discharge to wetlands during sum- mer, fall, and winter. The distribution of precipitation across the United States is affected by major climatic patterns. In North America, maximum rainfall is found on the western slopes of mountain ranges in the West, along the east coast, and in Hawaii. Tropical areas such as Florida and Puerto Rico also receive large quantities of precipitation. By contrast, precipitation is minimal in the continental interior where the atmosphere is dry; the driest part of North America is the southwest- ern desert. Wetlands are most abundant in areas with ample precipitation. Evapotranspiration The loss of water to the atmosphere is an impor- tant component of the wetland water budget. Water is removed by evaporation from soil or surfaces of water bodies and by transpiration by plants (fig. 20). The combined loss of water by evaporation and tran- spiration is termed evapotranspiration (ET). Solar radiation, windspeed and turbulence, relative humid- ity, available soil moisture, and vegetation type and density affect the rate of ET. Evaporation can be mea- sured fairly easily, but ET measurements, which require measuring how much water is being tran- spired by plants on a daily, weekly, seasonal, or yearly basis, are much more difficult to make. For this rea- son scientists use a variety of formulas to estimate ET and there is some controversy regarding the best for- mula and the accuracy of these estimates (Gehrels and Mulamoottil, 1990; Carter, 1986; Dolan and others, 1984; Idso, 1981). Evapotranspiration is highly variable both sea- sonally and daily (Dolan and others, 1984). ET losses from wetlands vary with plant species, plant density, and plant status (whether the plants are actively grow- ing or are dormant). Seasonal changes in ET also relate to the water-table position (Ingram, 1983) (more water evaporates from the soil or is transpired by plants when the water table is closer to land sur- face) and also to temperature changes (more water evaporates or is transpired in hot weather than in cold). Daily ET rates are controlled chiefly by the energy available to evaporate water there is gener- ally less at night and on cool, cloudy days. Surface Water Surface water may be permanently, seasonally, or temporarily present in a wetland. Surface water is supplied to wetlands through normal streamflow, flooding from lakes and rivers, overland flow, ground- water discharge, and tides. Ground water discharged into wetlands also becomes surface water. Surface- water outflow from wetlands is greatest during the wet season and especially during flooding. Surface water may flow in channels or across the surface of a wet- land. Flow paths and velocity of water over the sur- face of a wetland are affected by the topography and vegetation within the wetland. Streamflow from wetlands that have a large com- ponent of ground-water discharge tends to be more evenly distributed throughout the year than stream- National Water Summary Wetland Resources: TECHNICAL ASPECTS 39 flow from wetlands fed primarily by precipitation (fig. 21).This is because ground-water discharge tends to be relatively constant in quantity compared with precipitation and snowmelt. In coastal areas, tides provide a regular and pre- dictable source of surface water for wetlands, affect- ing erosion, deposition, and water chemistry. The magnitude of daily high and low tides is affected by the relative position of the sun and the moon high- est and lowest tides usually occur during full or new moons. Where tidal circulation is impeded by bar- rier islands (for example, in the Albemarle-Pamlico Sound in North Carolina, where tides are primarily wind-driven) or dikes and levees, tidal circulation may be small or highly modified. Strong winds and storms can cause extreme changes in sea level, flood- ing both wetlands and uplands. Ground Water Ground water originates as precipitation or as seepage from surface-water bodies. Precipitation moves slowly downward through unsaturated soils and rocks until it reaches the saturated zone. Water also seeps from lakes, rivers, and wetlands into the saturated zone. This process is known as ground- water recharge and the top of the saturated zone is known as the water table. Ground water in the satu- rated zone flows through aquifers or aquifer systems composed of permeable rocks or other earth materi- als in response to hydraulic heads (pressure). Ground water can flow in shallow local aquifer systems where water is near the land surface or in deeper interme- diate and regional aquifer systems (fig. 22). Differ- ences in hydraulic head cause ground water to move back to the land surface or into surface-water bod- ies; this process is called ground-water discharge. In wetlands that are common discharge areas for differ- ent flow systems, waters from different sources can mix. Ground-water discharge occurs through wells, seepage or springs, and directly through ET where the water table is near the land surface or plant roots reach the water table. Ground-water discharge will influ- ence the water chemistry of the receiving wetland whereas ground-water recharge will influence the chemistry of water in the adjacent aquifer. Wetlands most commonly are ground-water dis- charge areas; however, ground-water recharge also occurs. Ground-water recharge or discharge in wet- lands is affected by topographic position, hydro- geology, sediment and soil characteristics, season, ET, and climate and might not occur uniformly through- out a wetland. Recharge rates in wetlands can be much slower than those in adjacent uplands if the upland soils are more permeable than the slightly permeable clays or peat that usually underlie wetlands. The accumulation and composition of peat in wetlands are important factors influencing hydrology and vegetation. It was long assumed that the dis- charge of ground water through thick layers of well- decomposed peat was negligible because of its low permeability, but recent studies have shown that these layers can transmit ground water more rapidly than previously thought (Chason and Siegel, 1986). Peatland type (fen or bog) and plant communities are affected by the chemistry of water in the surface lay- 30 ^ 20 LL. O 10 A. Perched bog J FMAMJ JASOND B. Ground-water fen m-Th-m n J FMAMJ JASOND Figure 21. Monthly streamflow from two wetlands in northern Minnesota; A, a perched bog whose inflow component is primarily precipitation, and B, a fen whose inflow component is primarily ground water. (Source: Modified from Boelter and Verry, 1977.) ers of the wetland; the source of water (precipitation, surface water, or ground water) controls the water chemistry and determines what nutrients are avail- able for plant growth. Ground-water flow in exten- sive peatlands such as the Glacial Lake Agassiz peatland in Minnesota may be controlled by the de- velopment of ground-water mounds (elevated water tables fed by precipitation) in raised bogs where ground water moves downward through mineral soils before discharging into adjacent fens (Siegel, 1983; Siegel and Glaser, 1987). Movement of the ground water through mineral soils increases the nutrient content of the water. Coastal wetlands and shallow embayments repre- sent the lowest point in regional and local ground- water flow systems; ground water discharges into these areas, sometimes in quantities large enough to affect the chemistry of estuaries (Valiela and Costa, 1988; The hydrology of a wetland is largely responsible for the vegetation of the wetland. Figure 22. Ground-water flow systems. Local ground-water flow systems are recharged at topographic highs and discharged at immediately adjacent lows. Regional ground-water flow systems are recharged at the major regional topographic highs and discharged at the major regional topographic lows. Intermediate flow systems lie between the other two systems. (Source: Modified from Winter, 1976.) 40 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Winter water table Low evapotranspiration Storage capacity limited to surface water Plants, except evergreens, have no leaves Spring water table Summer water table High evapotranspiration Storage capacity increases (surface and subsurface) Plants are actively growing The vegetation affects the value of the wet- land to animals and people. Fall water table Low evapotranspiration Storage capacity decreases Plants lose leaves and become dormant Figure 23. Seasonal changes in storage capacity and evapotranspiration (ET) in wetlands. Valiela and others, 1990). The quantity of ground water discharged varies throughout the tidal cycle, affecting the water chemistry of the wetland soils (Harvey and Odum, 1990; Valiela and others, 1990). Storage Storage in a wetland consists of surface water, soil moisture, and ground water. Storage capacity refers to the space available for water storage the higher the water table, the less the storage capacity of a wetland. Some wetlands have continuously high water tables, but generally, the water table fluctuates seasonally in response to rainfall and ET. Storage capacity of wetlands is lowest when the water table is near or at the surface during the dormant season when plants are not transpiring, following snowmelt, and (or) during the wet season (fig. 23). Storage capacity increases during the growing season as water tables decline and ET increases. When storage capacity is high, infiltration may occur and the wet- land may be effective in retarding runoff. When water tables are high and storage capacity is low, any addi- tional water that enters the wetland runs off the wet- land rapidly. SOME EFFECTS OF HYDROLOGY ON WETLAND VEGETATION The hydrology of a wetland is largely responsible for the vegetation of the wetland, which in turn affects the value of the wetland to animals and people. The duration and seasonality of flooding and (or) soil saturation, ground-water level, soil type, and drainage characteristics exert a strong influence on the number, type, and distribution of plants and plant communities in wetlands. Although much is known about flooding tolerance in plants, the effect of soil saturation in the root zone is less well understood. Golet and Lowry (1987) showed that surface flooding and duration of saturation within the root zone, while not the only factors influencing plant growth, accounted for as much as 50 percent of the variation in growth of some plants. Plant distribution is also closely related to wetland water chemistry; the water may be fresh or saline, acidic or basic, depending on the source(s). HYDROGEOLOGIC SETTSNGS The source and movement of water are very im- portant for assessing wetland function and predicting how changes in wetlands will affect the associated basin. Linkages between wetlands, uplands, and deepwater habitats provide a framework for protec- tion and management of wetland resources. Water moving into wetlands has chemical and physical char- acteristics that reflect its source. Older ground water generally contains chemicals associated with the rocks through which it has moved; younger ground water has fewer minerals because it has had less time in contact with the rocks. Which processes can and will occur within the wetland are determined by the characteristics of the water entering and the charac- teristics of the wetland itself its size, shape, soils, plants, and position in the basin. Because wetlands occur in a variety of geologic and physiographic settings, attempts have been made to group or classify them in such a way as to identify similarities in hydrology. For example, Novitzki (1979,1982) developed a hydrologic classification for Wisconsin wetlands based on topographic position and surface water-ground water interaction; Gosse- link and Turner (1978) grouped freshwater wetlands according to hydrodynamic energy gradients; and Brinson (1993) developed a hydrogeomorphic clas- sification for use in evaluating wetland function. (See the articles "Wetland Definitions and Classifications in the United States" and "Wetland Functions, Values, and Assessment" in this volume.) Wetlands, like lakes, are associated with features where water tends to col- lect. They are commonly found in topographic depres- sions, at slope breaks, in areas of stratigraphic change, and in permafrost areas (fig. 24) (Winter and Woo, 1990). Topographic Depressions Most wetlands occur in or originate in topo- graphic depressions these include lakes, wetland basins, and river valleys (fig. 24A). Depressions may be formed by movement of glaciers and water; action of wind, waves, and tides; and (or) by processes as- sociated with tectonics, subsidence, or collapse. National Water Summary Wetland Resources: TECHNICAL ASPECTS 41 Glacial movement. Glaciers shaped the land- scape of many of the Northern States and caused wetlands to form in mountainous areas such as the Rocky Mountains and the northern Appalachians. As the glaciers advanced over the Northern United States they gouged and scoured the land surface, making numerous depressions, depositing unsorted glacial materials, and burying large ice masses. As the cli- mate warmed, the glaciers retreated, leaving behind the depressions and the large masses of buried ice. As the temperatures continued to warm, the ice masses melted to form kettle holes. In many cases, water filled the depressions and kettle holes, forming lakes. As the lakes filled with sediments, they were replaced by wetlands. Water movement. Wetlands also are formed by the movement of water as it flows from upland areas toward the coast. The flow characteristics of water are partly determined by the slope of the streambed. On steeply sloping land, water generally flows rapidly through relatively deep, well-defined channels. As the slope decreases, the water spreads out over a wider area and channels usually become shallower and less defined. Shallow channels tend to meander or move back and forth across the flood plain. The changes in flow path sometimes result in oxbow lakes and flood- plain wetlands. When the river floods, the isolated oxbow lakes begin to fill with sediment, providing an excellent place for more wetlands to form. Obstruc- tion to the normal flow of water also can cause the water to change course and leave gouges in front of or channels around the obstruction, or can cause water to be impounded behind the obstruction. Many lakes and wetlands are formed behind dams made by humans or beavers. Wind, wave, and tidal action. Wetlands are com- mon in areas of sand dunes caused by wind, waves, or tides. Wetlands formed in the depressions between sand dunes are found in the Nebraska Sandhills, along the shoreline of the Great Lakes, and on barrier islands and the seaward margins of coastal States. In coastal States, tides, waves, and wind cause the move- ment of sand barriers and the closing of inlets, which often result in the formation of shallow lagoons with abundant associated emergent wetlands. Tectonic activities. Tectonic activity is respon- sible for depression wetlands such as Reelfoot Lake on the Mississippi River flood plain in Tennessee caused by the 1812 New Madrid earthquake. Earth- quakes result when two parts of the Earth's crust move relative to each other, causing displacement of land. When this occurs, depressions may result along the lines of displacement or the flow paths of rivers may be changed, leaving isolated bodies of water. When a source of water coincides with these depressions, wetlands can form. Subsidence and collapse features. Land subsi- dence and collapse also can form depressions in which wetlands and lakes occur. In some areas, es- pecially in the Southwest, pumping of ground water has caused the land above an aquifer to sink, form- ing depressions where water collects and wetlands develop. In karst topography (landscapes resulting from the solution of carbonate rocks such as lime- stone), such as is found in Florida, wetlands form in sinkholes. Collapse of volcanic craters produces ifeir - " Infrared color photograph of oxbow lakes in the drainage area of Hoholitna River near Sleetmute, Alaska. (Photograph courtesy of National Aeronautics and Space Administration.) Lotus in Reelfoot Lake, Tennessee. (Photograph by Virginia Carter, U.S. Geological Survey.) Coastal marsh along San Francisco Bay, California. (Photograph by Virginia Carter, U.S. Geological Survey.) This recently collapsed sinkhole, in central Florida, provides an ideal spot for a wetland to form. (Photograph by Terry H. Thompson, U.S. Geological Survey.) 42 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES A. Depressions and slope breaks Slope break B. Areas of stratigraphic change EXPLANATION ^E General direction of ground-water flow Average water table Forest vegetation Scrub-shrub vegetation Mil//)/ Emergent vegetation Hi Peat [ j Glacial till (low permeability) [" ] Sand and gravel (high permeability) Figure 24. Cross sections showing principal hydrogeologic settings for wetlands; A, slope break and depression, B, area of stratigraphic change, and C, permafrost area. calderas that fill with water and sediment and con- tain lakes or wetlands. Slope Breaks The water table sometimes intersects the land surface in areas where the land is sloping. Where there is an upward break or change in slope, ground water moves toward the water table in the flatter landscape (fig. 24A) (Roulet, 1990; Winter and Woo, 1990). Where ground water discharges to the land surface, wetlands form on the lower parts of the slope. Con- stant ground-water seepage maintains soil saturation and wetland plant communities. The Great Dismal Swamp of Virginia and North Carolina is maintained by seepage of ground water at the slope break at the bottom of an ancient beach ridge that runs along the western edge (Carter and others, 1994). Areas of Stratigraphic Change Where stratigraphic changes occur near land sur- face, the layering of permeable and less-permeable rocks or soils affects the movement of ground water. When water flowing through the more permeable rock encounters the less permeable rock, it is diverted along the surface of the less permeable rock to the land sur- face. The continual seepage that occurs at the surface provides the necessary moisture for a wetland (fig. 246). Fens in Iowa form on valley-wall slopes where a thin permeable horizontal layer of rock is sand- wiched between two less permeable layers and con- tinual seepage from the permeable layer causes the formation of peat (Thompson and others, 1992). Permafrost Areas Permafrost is defined as soil material with a temperature continuously below 32°F (Fahrenheit) for more than 1 year (Brown, 1974); both arctic and subarctic wetlands in Alaska are affected by perma- frost (figs. 24C and 25). Permafrost has low perme- ability and infiltration rates. As a result, recharge through permafrost is extremely slow (Ford and Bedford, 1987). In areas covered by peat, organic silt, or dense vegetation, permafrost is commonly close to the surface. In areas covered by lakes, streams, and ponds, permafrost can be absent or at great depth below the surface-water body. The surface or active layer of permafrost thaws during the growing season. In areas where permafrost is continuous, there is vir- tually no hydraulic connection between ground water in the surface layer and ground water below the per- mafrost zone. The imperviousness of the frozen soil slows drainage and causes water to stand in surface depressions, forming wetlands and shallow lakes. In discontinuous permafrost areas (fig. 25), un- frozen zones on south-facing slopes (in the northern hemisphere) and under lakes, wetlands, and large riv- ers provide hydraulic connections between the surface and the ground water below the permafrost zone. Ground-water discharge to wetlands from deeper aquifers can occur through the unfrozen zone (Will- iams and Waller, 1966; Kane and Slaughter, 1973). In discontinuous permafrost regions, whether a slope faces away from or toward the sun can determine the presence or absence of permafrost and thus influence the location and distribution of wetlands (Dingman and Koutz, 1974). Permafrost is sensitive to factors that upset the thermal equilibrium. Thermokarst fea- tures (depressions in the land surface caused by thaw- ing and subsequent settling of the land) may be caused by regional climatic change or human activities. These depressions formed by local thawing of permafrost are usually filled with wetlands. WATER QUALITY IN WETLANDS The water chemistry of wetlands is primarily a result of geologic setting, water balance (relative pro- portions of inflow, outflow, and storage), quality of inflowing water, type of soils and vegetation, and human activity within or near the wetland. Wetlands National Water Summary Wetland Resources: TECHNICAL ASPECTS 43 EXPLANATION | _| Generajly underlain by continuous permafrost | | Underlain by discon- tinuous permafrost | | Underlain by isolated masses of permafrost | | Generally free from permafrost I | Undefined Figure 25. Continuous, discontinuous, and sporadic permafrost areas of Alaska. (Source: Modified from Ford and Bedford, 1987.) dominated by surface-water inflow and outflow re- flect the chemistry of the associated rivers or lakes. Those wetlands that receive surface-water or ground- water inflow, have limited outflow, and lose water primarily to ET have a high concentration of chemi- cals and contain brackish or saline (salty) water. Ex- amples of such wetlands are the saline playas, wet- lands associated with the Great Salt Lake in Utah, and the permanent and semipermanent prairie potholes. In contrast, wetlands that receive water primarily from precipitation and lose water by way of surface- water outflows and (or) seepage to ground water tend to have lower concentrations of chemicals. Wetlands influenced strongly by ground-water discharge have water chemistries similar to ground water. In most cases, wetlands receive water from more than one source, so the resultant water chemistry is a composite chemistry of the various sources. Plants can serve as indicators of wetland chem- istry. In tidal wetlands, the distribution of salty water influences plant communities and species diversity. In freshwater wetlands, pH (a measure of acidity or alkalinity) and mineral and nutrient con- tent influence plant abundance and species diversity. HYDROLOCIC AND WATER-QUALITY FUNCTIONS OF WETLANDS Wetland hydrologic and water-quality functions are the roles that wetlands play in modifying or con- trolling the quantity or quality of water moving through a wetland. An understanding of wetland func- tions and the underlying chemical, physical, and bio- logical processes supporting these functions facili- tates the management and protection of wetlands and their associated basins. The hydrologic and water-quality functions of wetlands are controlled by the following: Landscape position (elevation in the drainage ba- sin relative to other wetlands, lakes, and streams) Topographic location (depressions, flood plains, slopes) Presence or absence of vegetation Type of vegetation type of soil The relative amounts of water flowing in and water flowing out of the wetland Local climate The hydrogeologic framework The geochemistry of surface and ground water Although broad generalizations regarding wetland functions can be made, effectiveness and magnitude of functions differ from wetland to wetland. Natural functions of wetlands can be altered or impaired by human activity. Although slow incremen- tal changes in the natural landscape can lead to small changes in wetlands, the accumulation of these small changes can permanently alter the wetland function (Brinson, 1988). Some of the major hydrologic and water-quality functions of wetlands (1) flood stor- age and stormflow modification, (2) ground-water recharge and discharge, (3) alterations of precipita- tion and evaporation, (4) maintenance of water qual- ity, (5) maintenance of estuarine water balance, and (6) erosion reduction are discussed below. Flood Storage and Stormflow Modification Wetlands associated with lakes and streams store floodwaters by spreading water out over a large flat area. This temporary storage of water decreases run- off velocity, reduces flood peaks, and distributes stormflows over longer time periods, causing tribu- tary and main channels to peak at different times. Wetlands with available storage capacity or those located in depressions with narrow outlets may store and release water over an extended period of time. In drainage basins with flat terrain that contains many depressions (for example, the prairie potholes and playa lake regions), lakes and wetlands store large volumes of snowmelt and (or) runoff. These wetlands have no natural outlets, and therefore this water is retained and does not contribute to local or regional flooding. A strong correlation exists between the size of flood peaks and basin storage (percentage of basin area occupied by lakes and wetlands) in many drain- age basins throughout the United States (Tice, 1968; The effectiveness and magnitude of a function varies from wetland to wetland. 44 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Wetlands can influence weather and climate. Hains, 1973; Novitzki, 1979, 1989; Leibowitz and others, 1992). Novitzki (1979, 1989) found that ba- sins with 30 percent or more areal coverage by lakes and wetlands have flood peaks that are 60 to 80 per- cent lower than the peaks in basins with no lake or wetland area. Wetlands can provide cost-effective flood control, and in some instances their protection has been recognized as less costly than flood-control measures such as reservoirs or dikes (Carter and oth- ers, 1979). Loss of wetlands can result in severe and costly flood damage in low-lying areas of a basin. Not all wetlands are able to store floodwaters or modify stormflow; some, in fact, add to runoff. Down- stream wetlands, such as those along the middle and lower reaches of the Mississippi River and its tribu- taries, are more effective at reducing downstream flooding than are headwater wetlands, largely as a result of larger storage capacities (Ogawa and Male, 1986). Runoff from wetlands is strongly influenced by season, available storage capacity, and soil perme- ability. Wetlands in basin headwaters are commonly sources of runoff because they are ground-water dis- charge areas. Wetlands in Alaska that are underlain by permafrost have little or no available storage capac- ity; runoff is rapid and flood peaks are often very high. Ground-Water Recharge and Discharge Ground-water recharge and discharge are hydro- logic processes that occur throughout the landscape and are not unique functions of wetlands. Recharge and discharge in wetlands are strongly influenced by local hydrogeology, topographic position, ET, wetland soils, season, and climate. Ground-water discharge provides water necessary to the survival of the wet- land and also can provide water that leaves the wet- land as streamflow. Most wetlands are primarily dis- charge areas; in these wetlands, however, small amounts of recharge can occur seasonally. Recharge to aquifers can be especially important in areas where ground water is withdrawn for agri- cultural, industrial, and municipal purposes. Wetlands can provide either substantial or limited recharge to aquifers. Much of the recharge to the Ogallala aqui- fer in West Texas and New Mexico is from the 20,000 to 30,000 playa lakes rather than from areas between lakes, ephemeral streams, and areas of sand dunes (Wood and Osterkamp, 1984; Wood and Sanford, 1994). Recharge takes place through the bottoms of some streams, especially in karst topography and in the arid West. Some recharge also takes place when floodwater moves across the flood plain and seeps down into the water-table aquifer. Cypress domes in Florida and prairie potholes in the Dakotas also are thought to contribute to ground-water recharge (Carter and others, 1979). Ground-water recharge from a wetland can be induced when aquifer water levels have been drawn down by nearby pumping. Most estuarine wetlands are discharge areas rather than recharge areas, primarily because they are on the low topographic end of local and regional ground-water flow systems. As the tide rises, water is temporarily stored on the surface of the wetland and in the wetland soils, where it mixes with the discharg- ing freshwater. The water moves back into the estu- ary or tidal river as the tide ebbs. Precipitation fall- ing on nontidal freshwater wetlands on barrier islands may recharge the shallow freshwater aquifer overly- ing the deeper salty water. Alterations of Precipitation and Evaporation Wetlands can influence local or regional weather and climate in several ways. Wetlands tend to moder- ate seasonal temperature fluctuations. During the sum- mer, wetlands maintain lower temperatures because ET from the wetland converts latent heat and releases water vapor to the atmosphere. In the winter, the warmer water of the wetland prevents rapid cooling at night; warm breezes from the wetland surface may prevent freezing in nearby uplands. Wetlands also modify local atmospheric circulation and thus affect moisture convection, cloud formation, thunderstorms, and precipitation patterns. Therefore, when wetlands are drained or replaced by impermeable materials, sig- nificant changes in weather systems can occur. Maintenance of Water Quality Ground water and surface water transport sedi- ments, nutrients, trace metals, and organic materials. Wetlands can trap, precipitate, transform, recycle, and export many of these waterborne constituents, and water leaving the wetland can differ markedly from that entering (Mitsch and Gosselink, 1993; Elder, 1987). Wetlands can maintain good quality water and improve degraded water. Water-quality modification can affect an entire drainage basin or it may affect only an individual wetland. Water chemistry in basins that contain a large proportion of wetlands is usually different from that in basins with fewer wetlands. Basins with more wetlands tend to have water with lower specific con- ductance and lower concentrations of chloride, lead, inorganic nitrogen, suspended solids, and total and dissolved phosphorus than basins with fewer wet- lands. Generally, wetlands are more effective at re- moving suspended solids, total phosphorus, and ammonia during high-flow periods and more effec- tive at removing nitrates at low-flow periods (John- ston and others, 1990). Novitzki (1979) reported that streams in a Wisconsin basin, which contained 40 per- cent wetland and lake area, had sediment loads that were 90 percent lower than in a comparable basin with no wetlands. Wetlands may change water chemistry sequentially; that is, upstream wetlands may serve as the source of materials that are transformed in down- stream wetlands. Estuaries and tidal rivers depend on the flow of freshwater, sediments, nutrients, and other constituents from upstream. Wetlands filter out or transform natural and an- thropogenic constituents through a variety of biologi- cal and chemical processes. Wetlands act as sinks (where material is trapped and held) for some mate- rials and sources (from which material is removed) of others. For example, wetlands are a major sink for heavy metals and for sulfur, which combines with metals to form relatively insoluble compounds. Some wetland mineral deposits (bog iron, manganese) are or have been important metal reserves in the past. Or- ganic carbon in the form of plant tissues and peat National Water Summary Wetland Resources: TECHNICAL ASPECTS 45 Gaseous Nitrogen Surface- water inflow (NH3 J Ground- Living plant Decaying plant material Detritus / __, Surface- M '> water outflow (NH3> Ground- water outflow EXPLANATION Bacteria change gaseous nitrogen (N 2 ) to ammonia (NH 3 ). Bacteria change ammonia (NH3) to nitrate (NOJ} (another form of nitrogen that the plant can use). Plant roots absorb ammonia and (or) nitrate formed in processes Q and Q and incorporate nitrogen into the plant proteins and nucleic acids that nourish the plant. Nitrogen compounds of decaying plants are broken down by bacteria and release ammonia that can be recycled through steps 0 and 0. Bacteria change nitrate to gaseous nitrogen. Figure 26. Simplified diagram of the nitrogen cycle in a wetland. accumulates in wetlands creating a source of water- borne dissolved and particulate organic materials. Some materials, for example nutrients, are changed from one form to another as they pass through the wetland (fig. 26). Most stored materials in wetlands are immobilized as a result of prevailing water chem- istry and hydrology, but any disturbance can result in release of those materials. The water purification functions of wetlands are dependent upon four principal components of the wet- land substrate, water, vegetation, and microbial popu- lations (Hammer, 1992; Hemond and others, 1987). Substrates. Wetland substrates provide a reac- tive surface for biogeochemical reactions and habi- tat for microbes. Wetland soils are the medium in which many of the wetland chemical transformations occur and the primary storage area of available chemicals for most plants (Mitsch and Gosselink, 1993). Organic or peat soils differ from mineral soils in their biogeochemical properties, including their ability to hold water and bind or immobilize mineral constituents. Water. Ground and surface waters transport solid materials and gases to the microbial and plant communities, remove the by-products of chemical and biological reactions from the wetlands, and maintain the environment in which the essential biochemical processes of wetlands occur. Flooding or soil satura- tion causes oxygen-deficient conditions that markedly influence many biological transformations. Vegetation. Wetland vegetation reduces the flow and decreases velocities of water, causing the depo- sition of mineral and organic particles and constitu- ents attached to them, such as phosphorus or trace metals. Plants introduce oxygen to the generally oxy- gen-deficient soil environment through their roots, creating an oxidized root zone where bacterial trans- formations of nitrogenous and other compounds can occur (Good and Patrick, 1987). Plants also provide a surface for microbial colonization. Wetland plants remove small quantities of nutrients, trace metals, and other compounds from the soil water and incorporate them into plant tissue, which may later be recycled in the wetland through decomposition, stored as peat, or transported from the wetland as particulate mat- ter (Boyt and others, 1977; Tilton and Kadlec, 1979; Hammer, 1992). Microbes. The microbial community, which includes bacteria, algae, fungi, and protozoa, is re- sponsible for most of the chemical transformations that occur in wetlands. In order to meet their meta- bolic needs, microbes use up oxygen; transform nu- trients, manganese, and iron; and generate methane, hydrogen sulfide gas, and carbon dioxide. Wetlands serve as short-term or long-term sedi- ment sinks. Floodwater spreading out across a wet- land decreases in velocity, and sediments settle out and are trapped within the wetland. Some of this sedi- ment may be transported out of the wetland during future flooding. Sediment deposition in estuarine wetlands provides a constant input that is of special importance for maintenance of wetlands acreage dur- ing periods of sea-level rise (Bricker-Urso and oth- ers, 1989). The ability of wetlands to filter and transform nutrients and other constituents has resulted in the construction and use of artificial wetlands in the United States and other countries to treat wastewater and acid mine drainage (Hammer, 1989, 1992; Wieder, 1989). However, individual wetlands have a limited capacity to absorb nutrients and differ in their ability to do so (Tiner, 1985). A wetland's effective- ness in improving water quality depends on hydro- logic patterns, amount and type of vegetation, time of year, and the constituent of concern (Zedler and others, 1985). Estuarine Water Balance Estuaries receive freshwater from precipitation, ground-water discharge, streamflow, and overland flow. Ground water discharges through shallow- water sediments of the estuary or through marsh soils and can affect the nutrient balance and salinity of the 46 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Low flow EXPLANATION General direction of surface-water flow [ | Freshwater | | Brackish water Freshwater/brackish-water interface [ | Saltwater Brackish-water/saltwater interface Figure 27. Movement of the freshwater-saltwater interface in an estuary during periods of high flow and during periods of low flow. receiving waters (Valiela and others, 1978; Harvey and Odum, 1990). Estuarine salinity decreases dur- ing periods of high streamflow as the freshwater-salt- water interface moves down the estuary from the stream toward the sea (fig. 27). Estuarine salinity in- creases as streamflow decreases and the interface moves up the estuary. Estuarine plants and animals are well adjusted to these normal seasonal fluctua- tions in salinity. Water temporarily stored in flood- plain wetlands upstream from the estuary deposits sediment and nutrients, and water leaving these wet- lands exports decomposition products and organic de- tritus to the estuary. This temporary storage of water and the concurrent decrease in flow velocity aid in controlling the timing and size of the freshwater in- flux to the estuary. For example, the freshwater wet- lands of the Barataria Basin in Louisiana serve as a major freshwater reservoir for maintenance of favor- able salinities in the brackish zone, and the major pulse of materials to the estuary coincides with the arrival of migrant fish for growth and spawning. Leaves that fall in flood-plain wetlands are broken down and enriched by microbial action and produce high-quality food for detrital based food chains in the estuary. Alterations in the timing and quality of streamflow and associated suspended particulate and dissolved material, caused by dams or artificial drain- age, can alter the chemistry of coastal waters and affect the organisms that inhabit them. Wetlands reduce the erosive forces of wind and waves. Erosion Reduction Wetlands reduce shoreline erosion by stabilizing sediments and absorbing and dissipating wave energy (Hammer, 1992). The ability of wetlands to stabilize and protect shorelines depends on their capacity to reduce the erosive forces of wind and waves. Beaches and shallow vegetated wetlands protect shorelines in moderate and small storms if the water does not carry excessive amounts of abrasive floating debris. Wet- land vegetation decreases water velocities through friction and causes sedimentation in shallow water areas and flood-plain wetlands, thus decreasing the erosive power of the water and building up natural levees. Trees are excellent riverbank stabilizers and have been planted to reduce erosion along United States shorelines. Other wetland plants such as bul- rushes, reeds, cattails, cordgrass, and mangroves can also successfully withstand wave and current action. When vegetation is removed, streambanks col- lapse and channels widen and (or) deepen; removal of wetland vegetation can turn a sediment sink into a sediment source. The dissipation of erosive forces by vegetation differs from wetland to wetland and de- pends upon vegetative composition and root structure, sediment type, and the frequency and intensity of water contact with the bank. SUMMARY Wetlands are complex ecosystems in which ground water and surface water interact, but because ground water cannot be directly observed, its role in the hydrology of wetlands is sometimes more diffi- cult to understand than that of surface water. Many wetlands owe their existence not only to poor drain- age at the site but also to the discharge of ground water at the site. The hydrology of a wetland determines what functions it will perform. Each wetland is unique, but those with similar hydrologic settings generally perform similar functions. References Cited Boelter, D.H., and Verry, E.S., 1977, Peatland and water in the northern Lake States: U.S. Department of Agricul- ture Forest Service General Technical Report NC-31, 22 p. Boyt, F.L., Bayley, S.E., and Zoltek, John, Jr., 1977, Removal of nutrients from treated municipal wastewater by wet- land vegetation: Journal of Water Pollution Control Federation, v. 49, no. 5, p. 789-799. Bricker-Urso, Suzanne, Nixon, S.W., Cochran, J.K., Hirschberg, D.J., and Hunt, C.D., 1989, Accretion rates and sediment accumulation in Rhode Island salt marshes: Estuaries, v. 12, no. 4, p. 300-317. Brinson, M.M., 1988, Strategies for assessing the cumula- tive effects of wetland alteration on water quality: En- vironmental Management, v. 12, no. 5, p. 655-662. ____1993, A hydrogeomorphic classification for wet- lands: U.S. Army Corps of Engineers, Technical Report WRP-DE-4, 79 p. Brown, R. J. E., 1974, Distribution and environmental re- lationships of permafrost: Canada National Commit- tee for the Hydrologic Decade, p. 1-5. Carter, Virginia, 1986, An overview of the hydrologic con- cerns related to wetlands in the United States: Cana- dian Journal of Botany, v. 64, no. 2, p. 364-374. Carter, Virginia, Bedinger, M.S., Novitzki. R.P., and Wilen, W.O., 1979, Water resources and wetlands, in Greeson, P.E., Clark, J.R. and Clark, J.E., eds., Wetland func- tions and values The state of our understanding: Min- neapolis, Minnesota, Water Resources Association, p. 344-376. Carter, Virginia, Gammon, P.T., and Garrett, M.K.,1994, National Water Summary Wetland Resources: TECHNICAL ASPECTS 47 Ecotone dynamics and boundary determination in the Great Dismal Swamp, Virginia and North Carolina: Ecological Applications, v. 4, no. 1, p. 189-203. Chason, D.B., and Siegel, D.I., 1986, Hydraulic conductiv- ity and related physical properties of peat, Lost River Peatland, Northern Minnesota: Soil Science, v. 142, no. 2, p. 91-99. Dingman, S.L., and Koutz, F.R., 1974, Relations among veg- etation, permafrost, and potential insolation in Central Alaska: Arctic and Alpine Research, v. 6, no. 1, p. 37-42. Dolan, T.J., Hermann, A.J., Bayley, Suzanne, and Zoltek, John, 1984, Evapotranspiration of a Florida, U.S.A., freshwater wetland: Journal of Hydrology, v. 74, p. 355-371. Elder, J.F., 1987, Factors affecting wetland retention of nutrients, metals, and organic materials, in Kusler, J.A., and Brooks, Gail, eds., Wetland hydrology: National Wetland Symposium, 1987, Proceedings, p. 178-184. Ford, Jesse, and Bedford, B.L., 1987, The hydrology of Alaskan wetlands, USA A review: Arctic and Alpine Research, v. 19, no. 3, p. 209-229. Gehrels, Jim, and Mulamoottil, George, 1990, Hydrologic processes in a southern Ontario wetland: Hydro- biologia, v. 208, p. 221-234. Golet, F.C. and Lowry, D.J., 1987, Water regimes and tree growth in Rhode Island Atlantic white cedar swamps, in Laderman, A.D, ed., Atlantic white cedar wetlands: Boulder, Colo., Westview Press, p. 91-110. Good, B.J., and Patrick, W.H., Jr., 1987, Root-water-sedi- ment interface processes, in Reddy, K.R., and Smith, W.H., eds., Aquatic plants for water treatment and re- source recovery: Orlando, Fla., Magnolia Publishing Company, p. 359-371. Gosselink, J.G., and Turner, R.E., 1978, The role of hydrol- ogy in freshwater wetland ecosystems, in Good, R.E., Whigham, D.F., and Simpson, R.L., eds., Freshwater wetlands Ecological processes and management po- tential: New \brk. Academic Press, p. 63-78. Hains, C.F., 1973, Floods in Alabama Magnitude and fre- quency, based on data through September 30, 1971: U.S. Geological Survey and Alabama Highway Dept., 38 p. Hammer, D.A., 1989, Constructed wetlands for waste water treatment: Chelsea, Mich., Lewis Publishers, Inc., 831 P- ____1992, Creating freshwater wetlands: Chelsea, Mich., Lewis Publishers, 298 p. Harvey, J.W., and Odum, W.E., 1990, The influence of tidal marshes on upland groundwater discharge to estuaries: Biogeochemistry, v. 10, p. 217-236. Hemond, H.F., Army, T.P., Nuttle, W.K., and Chen, D.G., 1987, Element cycling in wetlands Interactions with physical mass transport, in Kites, R.A., and Eisenreich, S.J., eds., Sources and fates of aquatic pollutants: Wash- ington, D.C., American Chemical Society, Advances in Chemistry Series 216, p. 519-537. Idso, S.B., 1981, Relative rates of evaporative water losses from open and vegetation covered water bodies: Ameri- can Water Resources Bulletin, v. 17, no. 1, p. 46 48. Ingram, H.A.P., 1983, Hydrology, in Gore, A.J.P., ed., Eco- systems of the world, 4A, Mores Swamp, bog, fen and moor: New "York, Elsevier Scientific Publishing Com- pany, p. 67-158. Johnston, C.A., Detenbeck, N.E., and Niemi, G.J., 1990, The cumulative effect of wetlands on stream water quality and quantity A landscape approach: Bio- geochemistry, v. 10, p. 105-141. Kane, D.L., and Slaughter, C.W., 1973, Recharge of a cen- tral Alaska lake by subpermafrost groundwater: Sec- ond International Conference on Permafrost, Siberia, 1973, Proceedings, p. 458^68. Leibowitz, S.G., Abbruzzese, Brooks, Adamus, P.R., Hughes, L.E., Iris, J.T., 1992, A synoptic approach to cumulative impact assessment A proposed method- ology, in McCannell, S.G., and Hairston, A.R., eds.: U.S. Environmental Protection Agency, EPA/600/R- 92-167, 127 p. Mitsch, W.J., and Gosselink, J.G., 1993, Wetlands: New York, Van Nostrand Reinhold, 722 p. Novitzki, R.P., 1978, Hydrology of the Nevin Wetland near Madison, Wisconsin: U.S. Geological Survey Water- Resources Investigations 78^8, 25 p. ____1979, Hydrologic characteristics of Wisconsin's wet- lands and their influence on floods, stream flow, and sediment, in Greeson, P.E., and Clark, J.R., eds., Wet- land functions and values The state of our under- standing: Minneapolis, Minn., American Water Re- sources Association, 674 p. ____1982, Hydrology of Wisconsin wetlands: Wisconsin Geological Natural History Survey, Information Circu- lar 40, 22 p. .1989, Wetland hydrology, in Majumdar, S.K., Brooks, R.P., Brenner, F.J., and Tiner, R.W., Jr., eds., Chapter Five, Wetlands ecology and conservation Emphasis in Pennsylvania: The Pennsylvania Academy of Science, p. 47-64. Ogawa, Hisashi, and Male, J.W, 1986, Simulating of flood mitigation role of wetlands: Journal of Water Resources Planning and Management, v. 112, no. 1, p. 114-127. Roulet, N.T., 1990, Hydrology of a headwater basin wet- land Groundwater discharge and wetland mainte- nance: Hydrological Processes, v. 4, p. 387-400. Roulet, N.T., and Woo, Ming-ko, 1986, Hydrology of a wetland in the continuous permafrost region: Journal of Hydrology, v. 89, p. 73-91. Rykiel, E. J., 1984, General hydrology and mineral budgets for Okefenokee Swamp Ecological significance, in Cohen, A.D., Casagrande, D.J., Andrejko, M.J., and Best, G.R., eds., The Okefenokee Swamp Its natural history, geology, and geochemistry: Los Alamos, N. Mex., Wetland Surveys, p. 212-228. Siegel, D.I., 1983, Ground water and the evolution of pat- terned mires, glacial lake Agassiz peatlands, northern Minnesota: Journal of Ecology, v. 71, p. 913-921. ____1992, Groundwater hydrology, in Wright, H.E., Jr., Coffin, B.A., and Asseng, N.E., eds., The patterned peatlands of Minnesota: Minnesota, University of Min- nesota Press, p. 163-172. Siegel, D.I., and Glaser, P.H., 1987, Groundwater flow in a bog-fen complex, Lost River peatland, Northern Min- nesota: Journal of Ecology, v. 75, p. 743-754. Thompson, C.A., Bettis, E.A., III, and Baker, R.G., 1992, Geology of Iowa Fens: Journal of Iowa Academy of Science, v. 99, no. 2-3, p. 53-59. Tice. R. H., 1968, Magnitude and frequency of floods in the United States: U.S. Geological Survey Water-Supply Paper 1672, 13 p. Tilton, D. L., and Kadlec, R. H., 1979, The utilization of a fresh-water wetland for nutrient removal from second- arily treated waste water effluent: Journal of Environ- mental Quality, v. 8, no. 3, p. 328-334. Tiner, R.W., Jr., 1985, Wetlands of New Jersey: Newton Corner, Mass., U.S. Fish and Wildlife Service, National Wetlands Inventory, 117 p. Valiela, Ivan, and Costa, J.E., 1988, Eutrophication of But- termilk Bay, a Cape Cod coastal embayment Concen- trations of nutrients and watershed nutrients and wa- tershed nutrient budgets: Environmental Management, v. 12, no. 4, p. 539-553. Valiela, Ivan, Costa, J.E., Foreman, Kenneth, Teal, J.M., Howes, Brian, and Aubrey, David, 1990, Transport of groundwater-borne nutrients from watersheds and their effects on coastal waters: Biogeochemistry, v. 10, p.177-197. Valiela, Ivan, Teal, J.M., Volkmann, Susanne, Shafer, 48 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Deborah, and Carpenter, E.J., 1978, Nutrient and par- ticulate fluxes in a salt marsh ecosystem Tidal ex- changes and inputs by precipitation and groundwater: Limnology and Oceanography, v. 23, no. 4, p. 708-812. Wieder, R.K., 1989, A survey of constructed wetlands for acid coal mine drainage treatment in the eastern United States: Wetlands, v. 9, no. 2, p. 299-315. Williams, J.R., and Waller, R.M., 1966, Ground water oc- currence in permafrost regions of Alaska: National Research Council, p. 159-164. Winter, T.C., 1976, Numerical simulation analysis of the interaction of lakes and ground water: U.S. Geologi- cal Survey Professional Paper 1001, 45 p. ____ 1981, Uncertainties in estimating the water balance of lakes; Water Resources Bulletin, v. 17, no. 1, p. 82-115. Winter, T.C., and Woo, Ming-Ko, 1990, Hydrology of lakes and wetlands: Surface Water Hydrology: The Geologi- cal Society of America, v. O-l, p. 159-187. Wood, W.W., and Osterkamp, W.R., 1984, Recharge to the Ogallala aquifer from Playa Lake Basins on the Llano Estacado: Wetstone, G.A., ed., Ogallala Aquifer Symposium II, Lubbock, Texas, 1984, Proceedings, p. 337-349. Wood, W.W., and Sanford, W.E., 1994, Recharge to the Ogallala: 60 years after C. V. Theis' analysis, in Urban, L.V., and Wyatt, A.W., eds., Playa Basin Symposium: Texas Tech University, Lubbock, Texas, 1994, 324 p. Zedler, J.B., Huffman, Terry, Josselyn, Michael, eds., 1985, Pacific Regional Wetland Functions: Proceedings of a workshop held at Mill Valley, Calif., April 14-16,1985, Amherst, Mass., The Environmental Institute, Univer- sity of Massachusetts, Publication no. 90-3, 162 p. FOR ADDITIONAL INFORMATION: Virginia Carter, U.S. Geological Survey, 430 National Center, Reston, VA 22092 U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources: TECHNICAL ASPECTS 49 Technical Aspects of Wetlands Wetlands as Bird Habitat By Robert E. Stewart, Jr. 1 Figure 28. This wetland in California is habitat for migrating snow geese. (Photograph by fames R. Nelson, California Department of Fish and Game.) The value of a wet- land to a specific bird species is affected by the presence of surface water and the duration and timing of flooding. One of the best known functions of wetlands is to provide a habitat for birds (fig. 28). Humans have known of the link between birds and wetlands for thousands of years. Prehistoric people drew pictures of birds and wetlands on cave walls, scratched them onto rocks, and used them in the design of artifacts (fig. 29); and Native American lore provides accounts of bird hunts in wetlands. Wetlands are important bird habitats, and birds use them for breeding, nesting, and rearing young (fig. 30). Birds also use wetlands as a source of drinking water and for feeding, resting, shelter, and social interactions. Some waterfowl, such as grebes, have adapted to wetlands to such an extent that their survival as individual species depends on the availability of certain types of wetlands within their geographic range. Other species, such as the northern pintail or the American widgeon, use wetlands only during some parts of their lives. Wetlands occupy only a small part of the land- scape that is now the conterminous United States 11 percent in 1780 and just 5 percent in 1980 (Dahl and others, 1991). Nonetheless, they are important to birds. During the past 20 years, policies and programs that encourage altering, draining, or filling of wet- lands have decreased, and policies that encourage wetland conservation and restoration have increased. (See article "Wetland Protection Legislation" in this volume.) Among the wetland attributes society seeks to protect and conserve are those that benefit wildlife, particularly migratory birds. This article discusses the benefits that wetlands provide for birds and the effects of wetland losses on birds. Figure 29. The importance of wetland birds to ancient people is portrayed in these two artifacts. The petroglyph at the left, created between A.D. 1300 and 1650, is located at Petroglyph National Monument near Albuquerque, N. Mex. The clay "duck pot" at the right, fired between 200 B.C. and A.D. 500, was unearthed at Hopewell Culture National Historical Park, Chillicothe, Ohio. (Photographs courtesy of the National Park Service.) National Biological Service. 50 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES The geographic location of a wet- land may determine how and when birds will use it. Figure 30. This baby heron will be raised in a wetland environment. (Photograph courtesy of National Biological Service.) Figure 31. The raccoon is a wetland predator that eats eggs and preys on birds. (Photo- graph courtesy of National Biological Service.) Figure 32. The American alligator is an effective and voracious predator of wetland birds in the South. (Photo- graph courtesy of National Biological Service.) Figure 33. This American bittern, with its protective coloration, is well hidden in the vegetation. (Photograph by James Leopold, National Biological Service.) WETLAND FACTORS THAT AFFECT BIRDS The relation between wetlands and birds is shaped by many factors. These include the availabil- ity, depth, and quality of water; the availability of food and shelter; and the presence or absence of predators. Birds that use wetlands for breeding de- pend on the physical and biological attributes of the wetland. Birds have daily and seasonal dependencies on wetlands for food and other life-support systems. The value of a wetland to a specific bird species is affected by the presence of surface water or moist soils and the duration and timing of flooding. Water might be present during the entire year, during only one or more seasons, during tidal inundation, or only temporarily during and after rainfall or snowmelt. At times water might not be present at the land surface, but might be close enough to the land surface to main- tain the vegetation and foods that are needed by birds. Birds may use wetlands located in depressions in an otherwise dry landscape, along streams, or in tidally influenced areas near shorelines. The availability or influence of water is a very important wetland feature to birds. It is not, however, the only feature that determines if birds will be present, how birds use the wetland, or how many kinds or numbers of birds may use the wetland. Other determining physical or biological factors include water depth and temperature, presence or absence of vegetation, patchiness or openness of vegetation, type of vegetation, foods, water chemistry, type of soils, and geographic or topographic location. Any varia- tions in any of these wetland features will cause subtle, but distinct, differences in bird use. Wetlands provide food for birds in the form of plants, vertebrates, and invertebrates. Some feeders forage for food in the wetland soils, some find food in the water column, and some feed on the vertebrates and invertebrates that live on submersed and emer- gent plants. Vegetarian birds eat the fruits, tubers, and leaves of wetland plants. Water temperatures influ- ence food production. Invertebrate production in the water column may ultimately depend on water tem- perature and the ability of a wetland to produce al- gae. Cold water might not be a hospitable environ- ment for small animals and plants that some wetland birds eat. However, water that is too warm also might not produce foods that some birds prefer. Wetland vegetation provides shelter from preda- tors and from the weather. The presence or absence of shelter may influence whether birds will inhabit a wetland or a nearby upland area. Predators are likely to abound where birds concentrate, breed, or raise their young. Wetlands form an important buffer or barrier to land-based predators and reduce the risk of predation to nesting or young birds. However, some predators, such as the raccoon (fig. 31), are well adapted to both wetland and upland environments, and take large numbers of both young and nesting birds. Mink forage for nesting or sleeping birds along the edges and interiors of wetlands. Other animals, such as the snapping turtle, the alligator (fig. 32), or the large-mouthed bass, are effective water-based predators of young birds, particularly young water- fowl. Snakes take their toll as well. Many bird spe- cies that are highly adapted to feeding in a wetland National Water Summary Wetland Resources: TECHNICAL ASPECTS 51 Figure 34. Major flyway corridors for migrating birds in the Western Hemisphere, (Source: From U.S. Fish and Wildlife Service files.) environment also have genetic adaptations that lower their risk of becoming prey. One such example is the bittern (fig. 33), which has excellent protective col- oration. The same vegetation that hides birds from predators also provides some shelter from severe weather. In spring, during cold and stormy weather, waterfowl such as canvasback ducks protect their young in the shelter of a marsh that is almost impen- etrable to wind. The geographic location of a wetland may deter- mine how and when birds will use it or use adjacent habitat. In the northern latitudes or at high altitudes, some wetlands are covered with ice in the winter and are temporarily "out of service" for birds adapted to a water environment, but emergent vegetation might still offer shelter and food for some species. Birds that eat fish, aquatic invertebrates, or submersed vegeta- tion cannot forage for food because of the ice cover. Some wetlands are on the migration path of water- fowl and other migratory birds and provide stopover locations for traveling birds (fig. 34). These birds might feed in agricultural fields during the day and return to the shelter of wetlands during the night. The "prairie potholes" are a special type of wet- land, found in the north-central part of the United States. These potholes are an example of a wetland type that is important to migrating waterfowl. Here the timing and duration of inundation and the salin- ity of the water are important factors in the produc- tion of plants and invertebrates used by birds. These, and many other wetland characteristics, are influ- enced by a number of things: Water-level fluctuations throughout the year, in re- sponse to rainfall and snowmelt, that maintain wetland zones such as wet meadows and marshes Short-term (years) and long-term (decades) cli- matic trends that cycle wetlands between a wet and dry state Interaction of surface and ground water Interaction of ground water with rocks and soils that influence salinity and other wetland water chemistry THE IMPORTANCE OF WETLANDS TO BIRDS Because of the great variety of wetlands, bird adaptation to and use of wetland environments dif- fers greatly from species to species. Birds' use of wetlands during breeding cycles ranges widely. Some birds depend on wetlands almost totally for breeding, nesting, feeding, or shelter during their breeding cycles. Birds that need functional access to a wetland or wetland products during their life cycle, especially during the breeding season, can be called "wetland dependent" (table 5). Other birds use wetlands only for some of their needs, or they might use both wet- land and upland habitats. Of the more than 1,900 bird species that breed in North America, about 138 spe- cies in the conterminous United States are wetland dependent (American Ornithologists'Union, 1983). Many bird species use forested wetlands as well as forested uplands, feeding on the abundant insects associated with trees (fig. 35). These birds are not de- 52 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Table 5. Wetland-dependent breeding birds of the conterminous United States, including federally endangered or threatened species and subspecies1 - 2 [Source: Data from American Ornithologists' Union, 1983; Niering, 1988; Ehrlich and others, 1992] Roseate spoonbill at a nesting rookery, (Photo- graph by Ronald F. Faille. U.S. Fish and Wildlife Service.) Snowy egret on the nest. (Photograph by David Hall, " U.S. Fish and Wildlife 1 Service.) * Green-backed heron. (Photograph by Thomas A. Muir, National Biological Service.) Cranes and their allies Yellow rail Black rail 3 California black rail Clapper rail 4 Light-footed clapper rail 4 California clapper rail 4 Yuma clapper rail King rail Virginia rail Sora rail Purple gallinule Common moorhen American coot Limpkin Sandhill crane (facultative) 4 Mississippi sandhill crane 4 Whooping crane Cuckoos Mangrove cuckoo Grebes Least grebe Pied-billed grebe Horned grebe Red-necked grebe Eared grebe Western grebe Herons and their allies American bittern Least bittern Great blue heron 4 Florida great white heron Great egret Snowy egret Little blue heron Tricolored heron Reddish egret Cattle egret Green-backed heron Black-crowned night heron Yellow-crowned night heron White ibis Glossy ibis White-faced ibis Roseate spoonbill 4 Wood stork Kingfishers Belted kingfisher This brown pelican is an endangered species. (Photograph by Thomas A. Muir, National Biological Service.) Loons Common loon Owls Short-eared owl Perching birds Flycatchers Alder flycatcher Willow flycatcher Gray flycatcher Swallows Tree swallow Northern rough-winged swallow Bank swallow Wrens Sedge wren Marsh wren Dippers American dipper Vireos Black-whiskered vireo Warblers 4 Bachman's warbler Prothonotary warbler Swainson's warbler Northern waterthrush Louisiana waterthrush Connecticut warbler Common yellowthroat Sparrows Savannah sparrow 3 Belding's savannah sparrow LeConte's sparrow Sharp-tailed sparrow Seaside sparrow 5 Dusky seaside sparrow 4 Cape sable sparrow Lincoln's sparrow Swamp sparrow Blackbirds Red-winged blackbird Tricolored blackbird Yellow-headed blackbird Great-tailed grackle Boat-tailed grackle Pelicans and their allies American white pelican Brown pelican 4 California brown pelican National Water Summary Wetland Resources: TECHNICAL ASPECTS 53 The American avocet. (Photograph courtesy of National Biological Service.) Double-crested cormorant Olivaceous cormorant Anhinga Shorebirds, Gulls, and Alcids Plovers, surfbirds, and turnstones Snowy plover Wilson's plover 4 Piping plover Killdeer {facultative) Oystercatchers American oystercatcher American black oystercatcher Avocets and stilts Black-necked stilt American avocet Sandpipers and allies Willet Spotted sandpiper Marbled godwit Common snipe American woodcock "Eskimo curlew Phalarope Wilson's phalarope Gulls and terns Laughing gull Franklin's gull Little gull Heerman's gull (facultative) Ring-billed gull California gull Herring gull Western gull Great black-backed gull Gull-billed tern Caspian tern Royal tern Elegant tern Sandwich tern 4 Roseate tern Common tern Forster's tern Least tern 4 California least tern Sooty tern Black tern Skimmers Black skimmer Colony of sandwich terns on the Chandeleur Islands, La. (Photograph courtesy of National Biological Service.) Vultures, Hawks, and Falcons Osprey American swallow-tailed kite 4 Everglade snail kite 4 Bald eagle Northern harrier Peregrine falcon 4 American peregrine falcon Waterfowl Swans Trumpeter swan Geese Canada goose Tree ducks Fulvous whistling duck Black-bellied whistling duck Surface feeding ducks Wood duck Green-winged teal American black duck Mottled duck Mallard Northern pintail Blue-winged teal Cinnamon teal Northern shoveler Gadwall American wigeon Bay ducks Canvasback Redhead Ring-necked duck Greater scaup Lesser scaup Sea ducks Harlequin duck White-winged scoter Common goldeneye Barrow's goldeneye Bufflehead Mergansers Hooded merganser Common merganser Red-breasted merganser Stiff-tailed ducks Ruddy duck These American wigeons will spend part of their lives in a wetland habitat and part in an upland environment. (Photograph courtesy of National Biological Service.) Male wood ducks. (Photo- graph by Thomas A. Muir, National Biological Service.) 1 Table arranged by group, species, and subspecies. To facilitate the use of this table, order of presentation differs from that normally used. 2 Does not include oceanic or pelagic birds. 3 Candidate for placement on endan- gered species list. 4 Federally endangered or threatened wetland-dependent bird species or subspecies. 5 Became extinct in 1987. 54 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Figure 35. Prothonotary warblers feed on insects of forested wetlands and uplands alike. (Photo- graph courtesy of National Biological Service.) Widespread draining and altering of wet- lands has affected bird populations. 10 15 20 PONDS PER SQUARE MILE Figure 36. The relation of pond density increase to number of ducks. (Source: After Belirose, 1977.) pendent on wetlands because they use both habitats equally well. Some birds, such as wood ducks, are found primarily in forested wetlands and are depen- dent on this wetland type. Many migratory birds are wetland dependent, using wetlands during their migration and breeding seasons. Migratory birds may spend the winter in wet- lands in the Southern United States, or farther south (fig. 34). Throughout winter, these birds use south- ern wetlands for food and nutrients to sustain them for their return trip north and the breeding season. Not all wetlands are of equal value to waterfowl and other birds. An inventory in the conterminous United States during the early 1950's showed that of 74.4 million acres of wetlands, 8.8 million acres had a high value for waterfowl, 13.6 million acres were of moderate value, 24.1 million acres were of low value, and 27.9 million acres were of negligible value (Shaw and Fredine, 1956, p. 17). These categories were identified on a State-by-state basis and were ranked according to use by waterfowl, with "high" being most used. The primary focus of this inventory was waterfowl; thus these rankings might not reflect wetland values for other birds. Also, the inventory was for only natural wetlands that had been little al- tered by human activities. The three areas of highest value are the Mississippi River corridor southward from Cairo, 111., and westward along the Texas gulf coast; the entire east coast from Maine southward through most of Florida; and the northern Midwest. THE INFLUENCE OF WETLANDS ON WATERFOWL POPULATIONS Considerable research has increased the under- standing of wetlands' influence on the numbers of waterfowl that breed and their breeding success. However, the relation between wetlands and the population and propagation of various waterfowl species is not well understood. This relation depends on: (1) the number of wetlands in the area; (2) the wetlands' size and water depth; (3) whether the wet- lands hold open water in the early spring or through late August; (4) the climate; and (5) the species of bird and the bird's adaptations to wetlands. In the prairie pothole region in the late 1970's, for example, as the number of wetlands in an area in- creased, populations of dabbling ducks increased, but at a ratio of less than 1:1 (fig. 36). In the past 20 years, the duck-pothole ratio has decreased, possibly due to decreases in upland cover and increases in predation. Belirose (1977) also found waterfowl densities and propagation to be related to the number of wet- lands per square mile; gener- ally, waterfowl densities and propagation increased as the number of wetlands increased. However, he found that mallard production decreased when the number of wetlands exceeded 12 per square mile. Different waterfowl spe- cies adapt to different wetland types, inhabit different geo- Prairie pothole region Parklands Mixed prairie Shortgrass prairie 25 30 40 graphic areas, and nest at different times. The rela- tion of many other species of birds to wetlands are undoubtedly just as complex. EFFECTS OF WETLAND LOSS AND DEGRADATION ON BIRDS About one-third of North American bird species use wetlands for food, shelter, and (or) breeding (Kroodsma, 1979). Thus, widespread draining and al- tering of wetlands has affected bird populations. Be- cause most of the wetland drainage and alteration oc- curred between the 1930'sand 1950, before scientific estimates of bird populations began, most estimates of population declines are inferred. Before the pas- sage of the Migratory Bird Treaty Act in 1918, the reduction in waterfowl populations was blamed largely on excessive hunting and wetland drainage (Day, 1959). However, since 1930 most of the reduc- tion has been attributed to the loss or degradation of wetlands (Belirose and Trudeau, 1988) and the loss of suitable upland habitats that surround wetlands. For most wetland-dependent birds, habitat loss in breeding areas translates directly into population losses. As wetlands are destroyed, some birds may move to other less suitable habitats, but reproduction tends to be lower and mortality tends to be higher. Hence, the birds that breed in these poorer quality habitats will not contribute to a sustainable popula- tion through the years (Pulliam and Danielson, 1991). About one-half of the 188 animals that are fed- erally designated as endangered or threatened are wetland dependent (Niering, 1988). Of these, 17 are bird species or subspecies (table 5). These birds are categorized as endangered or threatened because their populations are so low that the risk of their extinc- tion is real and immediate. The circumstances that cause each species or subspecies to be endangered differ greatly. Wetland loss due to draining, filling, or altering of surface-water and ground-water flow is a concern to many people. Wetland degradation also has a sub- stantial effect on birds. Although wetland degradation is a serious problem, it is one that is more subtle and less understood than wetland losses. Degradation can take many forms: Amounts and periodicity of water supplies can be altered The quality of water flowing into and through a wetland can be modified The flows of sediments or freshwater to coastal marshes can be reduced Water levels can be stabilized in wetlands that oth- erwise would undergo beneficial drawdowns or water-table fluctuations Wetland vegetation may be altered by harvesting or by introducing exotic species, making it of little or no value to well and-dependent birds An example of wetland degradation is found in the Chesapeake Bay region. Nutrients and sediments entering the bay from agricultural, urban, and indus- trial areas have caused increased algal blooms, de- creased invertebrate production, and lowered oxygen levels. This degradation has reduced the acreage of seagrasses that form an important link in the food National Water Summary Wetland Resources: TECHNICAL ASPECTS 55 chain for invertebrates, fish, and wetland-dependent birds. The decline in the canvasback duck population in this area is thought to be directly related to the de- cline in seagrasses. Chemicals and sediments that move from agri- cultural areas into wetlands are two of the most per- vasive sources of degradation. The shift in human populations from inland areas to coastal areas of the United States has caused problems in coastal wet- lands through overloaded sewage treatment systems. The large and growing volume of industrial wastes that enter ground- and surface-water supplies also threatens to degrade wetlands. These threats, com- bined with habitat destruction, have a net negative ef- fect on the population of wetland birds. Thus, if the amount and quality of wetland habitat is substantially reduced, populations of wetland-dependent birds in the area also can be expected to decrease. SOME EFFORTS TO PRESERVE WETLAND BIRD HABITATS Many people believe that ownership or manage- ment of wetlands by public conservation agencies, such as the U.S. Fish and Wildlife Service, and by private organizations, such as the Nature Conser- vancy or the National Audubon Society, offers the best assurance that the highest value wetlands will be maintained for future generations. (A discussion of the agencies and organizations that participate in management and conservation of wetlands in each State can be found in the State Summaries section of this report.) A few early concerns for wetlands important to waterfowl are reflected in the creation of the first national wildlife refuge and in the establishment of the Federal Duck Stamp program. The first national wildlife refuge was created in 1903, by President Theodore Roosevelt, to protect a wetland Pelican Island, Florida (U.S. Fish and Wildlife Service, [19951). Concern for the loss of waterfowl led to the Federal Duck Stamp program that began in 1934 (Mitsch and Gosselink, 1993) and continues today. Duck stamps are sold to waterfowl hunters to pro- vide money for the purchase or preservation of wet- lands (fig. 37). Several international treaties are partly respon- sible for much of the formal wetland protection in this country the Migratory Bird Treaty and the Conven- tion on Wetlands of International Importance espe- cially as Waterfowl Habitat. "In 1918, the U[nited] S [tales] passed into law the Migratory Bird Treaty Act, ratifying a treaty with Great Britain, on behalf of Canada, that recognized the conservation respon- sibilities for more than 800 species of migratory birds shared by the two countries" (U.S. Fish and Wildlife Service, [1995]). Subsequent to that act, the United States developed the National Wildlife Refuge Sys- tem consisting of 500 reserves many of which are wetlands important to birds comprising more than 90 million acres (fig. 38). The system has the high- est ratio of wetlands to dry land in public ownership. The National Park Service manages the Everglades National Park and several preserves that also have high ratios of wetlands to dry lands. The Convention on Wetlands of International U.S. DEPARTMENT OF THE INTERIOR BIRD HUNTING AND U VOID AFTER JUNE 30.1995 $15 Figure 37. The purchase of duck stamps provides funds for the acquisition or protection of wetlands important to waterfowl. (Source: U.S. Fish and Wildlife Service.) Importance especially as Waterfowl Habitat, more commonly known as the "Ramsar Convention" is an intergovernmental treaty for international cooperation for the conservation of wetland habitats. The U.S. Fish and Wildlife Service is responsible for implementa- tion of the convention in the United States. A "List of Wetlands of International Importance" has been de- veloped by the convention. Sites on this list are known as "Ramsar Sites" and are wetlands that convention members have a special obligation to preserve. There are 15 Ramsar sites in this country (fig. 38). SUMMARY AND CONCLUSIONS Human activities have caused shifts in wetland- dependent bird populations since European settle- ment of the United States, especially since the be- ginning of the 20th century. Many acres of wetlands were drained between the 1930's and 1950, well be- fore any of the national bird surveys were begun. As a result, it is not possible to accurately determine the effects of habitat destruction on long-term wetland bird populations. It is apparent that there have been many changes in the distribution and numbers of wetland birds. Wetlands on breeding, migratory, or wintering areas are all important to sustain bird populations. As the wetland habitats in these areas are drained or altered, the ability of these areas to sustain bird populations decreases. Each species of wetland-dependent bird has a unique and complex set of needs for wetland About one-half of the 188 animals that are federally designated as endangered or threatened are wetland dependent. 56 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Izembek Lagoon National Wildlife Refuge and State Game Area, Alaska Forsvthe National Wildlife Refuge, New Jersey Okefenokee National Wildlife Refuge, Georgia and Florida Ash Meadows National Wildlife Refuge, Nevada Everglades National Park, Florida Chesapeake Bay Estuarine Complex, Maryland and Virginia Cheyenne Bottoms State Game Area, Kansas Cache-Lower White Rivers Joint Venture Area, Arkansas Horicon Marsh, Wisconsin Catahoula Lake, Louisiana Delaware Bay Estuary, Delaware, New Jersey, and Pennsylvania Pelican Island, Florida Caddo Lake, Texas Cache River and Cypress Creek, Illinois Connecticut River Complex, Connecticut Figure 38. Location of National Fish and Wildlife Refuge System reserves and Ramsar sites in the United States. (Source: U.S. Fish and Wildlife Service, 1993, [1995].) habitats that makes it difficult to generalize about how loss or degradation of wetlands affects bird popula- tions. It seems reasonable to expect, however, that as the numbers of wetlands in a region decline, so too will the numbers of wetland-dependent birds. In some parts of the United States, extensive wetland losses have displaced birds from large areas. Continued wetland losses probably will cause con- tinued losses of wetland birds. However, recent rec- ognition of the wetland values, and the effects of their losses, have provided incentives to maintain and re- store wetlands. References Cited American Ornithologists' Union, 1983, Check-list of North American Birds: Lawrence, Kans., Alien Press, Inc., 6th edition, 877 p. Bellrose, F.C., 1977, Species distribution, habitats, and characteristics of breeding dabbling ducks in North America, in Bookhout, T. A., 1977, Waterfowl and wel- lands An integrated review: Proceedings of a sym- posium held al the 39th Midwest Fish and Wildlife Conference, Madison, Wis., La Crosse Printing Co., Inc, 152 p. Bellrose, F. C., and Trudeau, N.M., 1988, Wetlands and their relationship to migrating and winter populations of wa- terfowl, v. I: Portland, Oreg., Timber Press, p. 183-194. Dahl, T.E., and Johnson, C.E., 1991, Wetlands Status and trends in the conterminous United States, mid-1970's to mid-1980's: Washington, D.C., U.S. Fish and Wild- life Service, 22 p. Day, A.M., 1959, North American waterfowl; Harrisburg, Pa., Stackpole Co., 363 p. Ehrlich, PR., Dobkin, D.S., and Wheye, Darryl, 1992, Birds in jeopardy: Stanford, California, Stanford University Press, 260 p. Kroodsma, D. E., 1979, Habitat values for nongame wet- land birds, in Greeson, P.E., Clark, J.R., and Clark, I.E. eds., 1979, Wetland functions and values The state of our understanding: Minneapolis, Minn., American Water Resources Association, p. 320-343. Mitsch, W.J., and Gosselink, J.G., 1993, Wetlands: New \brk, Van Nostrand Reinhold, 722 p. Niering, W.A., 1988, Endangered, threatened and rare wet- land plants and animals of the continental United States, in Hook, D.D., McKee, W.H., Jr., Smith, H.K., and oth- ers, 1988, The ecology and management of wetlands Volume I The ecology of wetlands: Portland, Oreg., Timber Press, 592 p. Pulliam, H.R., and Danielson, B.J., 1991, Sources, sinks and habitat selection A landscape perspective on popu- lation dynamics: The American Naturalist, v. 137, p. 850-866. Shaw, S.P., and Fredine, C.G., 1956, Wetlands of the United States Their extent and their value to waterfowl and other wildlife: U.S. Fish and Wildlife Service, Circu- lar 39, 67 p. U.S. Fish and Wildlife Service, 1993, Annual report of lands under control of the U.S. Fish and Wildlife Service as of September 30, 1993: Division of Realty, 43 p. U.S. Fish and Wildlife Service, [1995J, Wetlands of Inter- national Importance United States Participation in the "Ramsar" Convention, Ramsar. Iran, 1971, 11 p. FOR ADDITIONAL INFORMATION: Robert E. Stewart, Jr., National Biological Service, Southern Science Center, 700 Cajundome Boulevard, Lafayette, LA 70506 U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources: MANAGEMENT AND RESEARCH 57 Wetland Management and Research Wetland Protection Legislation By Todd H. Votteler1 and Thomas A. Muir2 The people of the United States have begun to recognize that wetlands have numerous and widespread benefits. However, many of the goods and services wetlands provide have little or no market value. Be- cause of this, the benefits produced by wetlands accrue primarily to the general public. Therefore, the Govern- ment provides incentives and regulates and manages wetland resources to protect the resources from deg- radation and destruction. Other mechanisms for wet- land protection include acquisition, planning, mitiga- tion, disincentives for conversion of wetlands to other land uses, technical assistance, education, and research. Although many States have their own wetland regulations, the Federal Government bears a major re- sponsibility for regulating wetlands. The five Federal agencies that share the primary responsibility for pro- tecting wetlands include the Department of Defense, U.S. Army Corps of Engineers (Corps); the U.S. En- vironmental Protection Agency (EPA); the Depart- ment of the Interior, U.S. Fish and Wildlife Service (FWS); the Department of Commerce, National Oce- anic and Atmospheric Administration (NOAA); and the Department of Agriculture, Natural Resources Conservation Service (NRCS) (formerly the Soil Con- servation Service). Each of these agencies has a dif- ferent mission that is reflected in the implementation of the agency's authority for wetland protection. The Corps' duties are related to navigation and water sup- ply. The EPA's authorities are related to protecting wetlands primarily for their contributions to the chemical, physical, and biological integrity of the Nation's waters. The FWS's authorities are related to managing fish and wildlife game species and threat- ened and endangered species. Wetland authority of NOAA lies in its charge to manage the Nation's coastal resources. The NRCS focuses on wetlands affected by agricultural activities. States are becoming more active in wetland pro- tection. As of 1993, 29 States had some type of wet- land law (Want, 1993). Many of these States have adopted programs to protect wetlands beyond those programs enacted by the Federal Government. As more responsibility is delegated from the Federal Government to the States, State wetland programs are gaining in importance. Thus far, States have devoted more attention to regulating coastal wetlands than in- land wetlands. The most comprehensive State pro- grams include those of Connecticut, Rhode Island, New York, Massachusetts, Florida, New Jersey, and Minnesota (Mitsch and Gosselink, 1993). Many of these States regulate those activities affecting wetlands that are exempt from the Clean Water Act, Section 404 program. (For more information on specific State wet- land protection programs, see the State Summary sec- tion of this volume.) Despite the current recognition of wetland ben- efits, many potentially conflicting interests still exist, such as that between the interests of landowners and the general public and between developers and con- servationists. Belated recognition of wetland benefits and disagreement on how to protect them has led to discrepancies in local, State, and Federal guidelines. Discrepancies in Federal programs are apparent in table 6, which shows programs that encourage con- version of wetlands and those that discourage conver- sion of wetlands. Conflicting interests are the source of much tension and controversy in current wetland protection policy. Although attempts are being made to reconcile some of these differences, many policies will have to be modified to achieve consistency. Despite all the government legislation, policies, and programs, wetlands will not be protected if the regulations are not enforced. Perhaps the best way to protect wetlands is to educate the public of their ben- efits. If the public does not recognize the benefits of wetland preservation, wetlands will not be preserved. Protection can be accomplished only through the co- operative efforts of citizens. FEDERAL WETLAND PROTECTION PROGRAMS AND POLICIES The Federal Government protects wetlands di- rectly and indirectly through regulation, by acquisi- tion, or through incentives and disincentives as de- scribed in table 6. Section 404 of the Clean Water Act is the primary vehicle for Federal regulation of some of the activities that occur in wetlands. Other pro- grams, such as the "Swampbuster" program and the Coastal Management and Coastal Barriers Resources Acts, provide additional protection. Coastal wetlands generally benefit most from the current network of statutes and regulations. Inland wetlands are more vulnerable than coastal wetlands to degradation or loss because current statutes and policies provide them less comprehensive protection. Several of the major Fed- eral policies and programs affecting wetlands are dis- cussed in the following few pages. Also discussed are some of the States' roles in Federal wetland policies. The Clean Water Act The Federal Government regulates, through Sec- tion 404 of the Clean Water Act, some of the activi- ties that occur in wetlands. The Section 404 program originated in 1972, when Congress substantially amended the Federal Water Pollution Control Act and created a Federal regulatory plan to control the dis- charge of dredged or fill materials into wetlands and other waters of the United States. Discharges are com- monly associated with projects such as channel con- struction and maintenance, port development, fills to create dry land for development sites near the water, and water-control projects such as dams and levees. Other kinds of activities, such as the straightening of river channels to speed the flow of water downstream If the public does not recog- nize the benefits of wetland preservation, wetlands will not be preserved. 1 University of Texas. 2 National Biological Service. 58 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Table 6. Federal programs that have significant effects on wetlands in the United States. A, Regulations encouraging wetland conversion. B, Regulations discouraging or preventing wetland conversion. C, Acquisitions discouraging or preventing wetland conversion. D, Other policies and programs preventing or discouraging wetland conversion. [Abbrevations: AFA, All Federal Agencies; ASCS, Agricultural Stabilization and Conservation Service; BLM, Bureau of Land Management; Corps, U.S. Army Corps of Engineers; CWS,Canadian wild I ife Service; DOD, Department of Defense; DOE, Department of Energy; DOI, Department of the Interior; DOT, Department of Transportation; A, ENCOURAGING WETLAND CONVERSION Program or Act Executive Order 12630, Constitutional Takings AFA Federal-Aid Highway Act of 1968 DOT Effect of program Provides a review process for agencies to protect against unintentional "takings" of private property.____________________________________ Highway construction can affect wetlands at every stage. Wetlands are often prime sites for highways. Federal Crop Insurance USDA Indirectly encourages farmers to place frequently inundated areas, including wetlands, into production. Federal Livestock Grazing USFS, BLM Overgrazing promotes the loss of riparian habitat. Flood Control Act of 1944 f P.L 78-534) Corps Authorized various flood-control projects resulting in wetland destruction. National Flood Insurance Program FEMA Encourages development in flood plains, which contain wetlands, by providing low-cost Federal insurance. Payment-in-Kind (PIK) Program USDA Indirectly encourages farmers to place previously unfarmed areas, including wetlands, into production. ________________________________ Small Reclamation Projects Acts of 1956 (70 Stat. 1044) DOI Encourages State and local participation in small western reclamation projects, which can destroy riparian habitat.________________________________ Surface Mining Control and Reclamation Act (P.L 95-87), (1977) DOI Establishes a program for regulating surface mining and reclaiming coal-mined lands, including wetlands, under the Office of Surface Mining, Reclamation, and Enforcement. Surface Transportation Revenue Act of 1991 (P.L 102-240) DOT Transportation projects directly and indirectly destroy wetlands. U.S. Tax Code IRS Encourages farmers to drain and clear wetlands through tax deductions and credits for development activities. Water Resources Development Act of 1976,1986,1988, 1990 (P.L.'s 94-587, 99-662,100-676,101-640) Corps Water development projects directly and indirectly destroy wetlands. B, DISCOURAGING OR PREVENTING WETLAND CONVERSION-ffepu/arVons Program or Act Effect of program Comprehensive Environmental Response Compensation and Liability Act (Superfund) (P.L. 96-510) (1980) * Coastal Barriers Resources Act (P.L. 96-348) (1982) * Coastal Zone Management Act (P.L. 92-583) (1972) Estuary Protection Act (P.L 90-454) (1968) * Federal Water Pollution Control (P.L. 92-500) (Clean Water Act) Section 404 (1972) Federal Water Project Recreation Act (P.L 89-72) (1965) Fish and Wildlife Coordination Act of 1956 Migratory Bird Conservation Act {45 Stat. 1222) (1929) National Wildlife Refuge Acts (numerous Acts) National Environmental Policy Act of 1969 (P.L. 91-190) Ramsar Convention (Treaty), adopted 1973, enforced from 1975 Rivers and Harbors Act of 1938 (52 Stat. 802) Rivers and Harbors Appropriation Act of 1899, Section 10 of the (30 Stat. 1151) Watershed Protection and Flood Prevention Act (68 Stat. 666) (1954) Wild and Scenic Rivers Act, (P.L. 90-542) (1968) Wilderness Act of 1964 (78 Stat. 890) AFA NOAA NOAA DOI Corps, EPA FWS, NMFS DOI, Corps DOI FWS FWS AFA FWS Corps Corps FWS, NRCS DOI, USDA DOI, USDA Establishes liability of the U.S. Government for damages to natural resources over which the U.S. has sovereign rights. Requires the President to designate Federal officials to act as trustees for natural resources, and to conduct natural resource damage assessments. Designates various undeveloped coastal barrier islands for inclusion in the Coastal Barrier Resources System. Designated areas are ineligible for Federal financial assistance that may aid development. Provides Federal funding for wetlands programs in most coastal States, including the preparation of coastal zone management plans. Authorized the study and inventory of estuaries, and the Great Lakes, and provided for management of designated estuaries between DOI and the States. Regulates many activities that involve the disposal of dredged and fill materials in waters of the United States, including many wetlands. Recreation and fish and wildlife enhancement must be considered by Federal water projects. Authorizes Federal funds for acquiring land for waterfowl refuges. Authorizes the development and distribution of fish and wildlife information and the development of policies and procedures relating to fish and wildlife. Established a commission to approve the acquisition of migratory bird habitat Numerous statutes establish refuges, many of which contain significant wetland acreage. Requires the preparation of an environmental impact statement of all major Federal actions significantly affecting the environment. Convention maintains a list of wetlands of international importance and encourages the wise use of wetlands. Provides that "due regard" be given to wildlife conservation in planning Federal water projects. Prohibits the unauthorized obstruction or alteration of navigable waters. Authorizes the FWS to investigate wildlife conservation on NRCS small watershed projects. Protects designated river segments from damming and other alterations without a permit. Requires review of Federal lands for inclusion in the National Wilderness Preservation System. Discussed in text. National Water Summary Wetland Resources: MANAGEMENT AND RESEARCH 59 Table 6 Continued. [Abbrevatiorts Continued. EPA, U.S. Environmental Protection Agency; FEMA, Federal Emergency Management Agency; FERC, Federal Energy Regulatory Commission; FmHA, Farmer's Home Administration; FWS, U.S. Fish and Wildlife Service; GSA, General Services Administration; IRS, Internal Revenue Service; NMFS, National Marine Fisheries Service; NOAA. National Oceanic and Atmospheric Administration; NFS, National Park Service; NRCS, Natural Resources Conservation Service; USCG, U.S. Coast Guard; USDA, U.S. Department of Agriculture; USFS, U.S. Forest Service] C, DISCOURAGING OR PREVENTING WETLAND CONVERSION Acquisitions Program or Act Imp^^tinfl Effect of program Coastal Wetland Planning, Protection and Restoration Act (P.L 101-646) (1990) Corps, FWS EPA, NMFS Provides for interagency wetlands restoration and conservation planning and acquisition in Louisiana, other coastal States, and the Trust Territories. Emergency Wetlands Resources Act of 1986 (P.L. 99-645} FWS Pays debts incurred by FWS for wetlands acquisition, and provides additional revenue sources. Federal Aid in Wildlife Restoration Act (1937) FWS (Ch.899,50Stat.917) Fish and Wildlife Conservation Act FWS (P.L 96-366) (1980) Provides grants to States for acquiring, restoring, and maintaining wildlife areas. Identifies land and water in the Western Hemisphere critical for migratory nongame birds. Land and Water Conservation Fund Act (1964) (P.L 88-578) FWS, NPS Acquires wildlife areas. LeaAct<62Stat.238)(1948) FWS Authorizes the acquiring and developing of various waterfowl management areas in California. Migratory Bird Hunting and Conservation Stamps (1934} ___________________(Ch.71.48Stat.452) FWS Acquires wetland easements using revenues from fees paid by hunters for duck stamps._______________________________ North American Waterfowl Management Plan (1986) FWS, CWS Establishes a plan for managing waterfowl resources by various methods, such as acquiring wetlands.___________________________________ North American Wetlands Conservation Act (1989) (P.L 101-233) FWS Encourages public/private partnerships by providing matching grants to organizations for protecting, restoring, or enhancing wetlands._____________________ Surface Transportation Revenue Act of 1991 __________ ___ (P.L 102-240) DOT Authorizes funding for wetland mitigation banks for State departments of transportation._________________________________ Transfer of Certain Real Property for Wildlife Conservation Purposes Act (62 Stat. 240) (1948) GSA, DOI Allows the GSA to transfer property to DOI, or States, for wildlife conservation. U.S. Tax Code Tax Reform Act of 1986 (P.L 99-514) IRS Provides deductions for donors of wetlands and to some nonprofit organizations. Water Bank Act (1970) (P.L 91-559} ASCS Leases wetlands and adjacent uplands from farmers for waterfowl habitat for 10-year periods. Wetlands Loan Act {1961} {P.L 87-383) FWS Provides interest-free loans for wetland acquisition and easements. D, DISCOURAGING OR PREVENTING WETLAND CONVERSION Other Policies and Programs Program or Act ''"9 Effect of program Endangered Species Act of 1973 (P.L 93-205) FWS Provides for the designation and protection of wildlife, fish, and plant species that are in danger of extinction. ____ * Executive Order 11990, Protection of Wetlands (1977) AFA Requires Federal agencies to minimize impacts of Federal activities on wetlands. * Executive Order 11988, Protection of Floodplains (1977) AFA Requires Federal agencies to minimize impacts of Federal activities on flood plains. Executive Order 12580, Superfund Implementation (1987) DOI Directs DOI to develop rules for assessing damages under CERCLA (Comprehensive Environmental Response Compensation and Liabilities Act} as a natural resource trustee. Federal Noxious Weed Act (P.L 93-629) (1975) DOI, USDA DOE, DOD Authorizes controlling the spread of noxious weeds on Federal lands. Federal Power Act (41 Stat. 1063) (1920) FERC FERC will cooperate with other Federal agencies in assessing proposed power projects, such as dams. FERC must consider protection of fish and wildlife resources. ____ Fish and Wildlife Coordination Act (1965) (P.L. 89-72) FWS Requires Federal agencies to consult with FWS before issuing permits for most water-resource projects. Food, Agriculture, Conservation, and Trade Act of 1990 (P.L. 101-624) NRCS Wetland Reserve Program purchases perpetual nondevelopment easements on farmed wetlands. Subsidizes restoration of croplands to wetlands. Food Security Act of 1985 (Swampbuster] (P.L. 99-198) ASCS, FWS, "Swampbuster" program suspends agricultural subsidies for farmers who convert wet- lands to agriculture. FmHA Conservation Easements program allows FmHA to eliminate some farm debts in exchange for long-term easements that protect wetlands and other areas._______ National Wildlife Refuge System Administration Act of 1966 (P.L 89-669) DOI Provides the guidelines for managing National Wildlife Refuges. Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 (P.L 101-646) FWS, USCG, EPA, Corps, NOAA Created a Federal program to prevent and control the spread of species that are aquatic nuisances. Oil Pollution Act of 1990 (P.L. 101-380) DOE, DOI, NOAA Enhanced the response to oil spills and required natural resource damage assessments. Tax Deductions for Conservation Easements (Section 6 of P.L 96-541) IRS Allows taxpayers to take a deduction for a qualified real property interest contributed to a conservation organization for conservation purposes. ______ U.S. Tax Code Reform Act of 1986 {P.L. 99-514} IRS Eliminates incentives for clearing land. Deductible conservation expenditures must be con- sistent with wetlands protection. Capital gains on converted wetlands treated as income. Water Resources Development Act of 1976, 1986, 1988,1990, (P.L's 94-587, 99-662,100-676,101-640) Corps States that future mitigation plans for Federal water projects should include "in kind" mitigation for bottom-land hardwood forests. 60 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES and clearing land, are regulated as Section 404 dis- charges if they involve discharges of more than inci- dental amounts of soil or other materials into wetlands or other waters. The Corps and the EPA share the responsibility for implementing the permitting program under Sec- tion 404 of the Clean Water Act However, Section 404(c) of the Clean Water Act gives the EPA authority to veto the permit if discharge materials at the selected sites would adversely affect such things as municipal water supplies, shellfish beds and fishery areas, wild- life, or recreational resources. By 1991, the EPA had vetoed 11 of several hundred thousand permits since the Act was passed (Schley and Winter, 1992). The review process for a Section 404 permit is shown in figure 39. After notice and opportunity for a public hearing, the Corps' District Engineer may is- sue or deny the permit. The District Engineer must comply with the EPA's Section 404(b)(l) Guidelines and must consider the public interest when evaluat- ing a proposed permit. Four questions related to the guidelines are considered during a review of an ap- plication: 1. Is the proposed discharge the least damaging prac- tical alternative? 2. Does the proposed discharge comply with other en- vironmental standards or regulations? 3. Will the proposed discharge significantly degrade wetlands? 4. Have all the appropriate and practical steps been taken to minimize potential harm to the wetlands? Wetland mitigation is often required, and if required, the permit applicant will need to develop a specific, detailed plan. Through a public interest review, the Corps tries to balance the benefits an activity may provide against the costs it may incur. The criteria applied in this pro- cess are the relative extent of the public and private need for the proposed structure or work and the ex- tent and permanence of the beneficial or detrimental effects on the public and private uses to which the area is suited. Some of the factors considered in the public interest review are listed in figure 39. Cumulative ef- fects of numerous piecemeal changes are considered in addition to the individual effects of the projects. The FWS, NOAA, and State fish and wildlife agencies, as the organizations in possession of most of the country's biological data, have important advi- sory roles in the Section 404 program. The FWS and NOAA (if a coastal area is involved) provide the Corps and the EPA with comments about the potential envi- ronmental effects of pending Section 404 permits. Other government agencies, industry, and the public are invited to participate through public notices of permit applications, hearings, or other information- collecting activities. However, the public interest re- view usually does not involve public comment unless the permit is likely to generate significant public in- terest or if the potential consequences of the permit are expected to be significant. All recommendations must be given full consideration by the Corps, but there is no requirement that they must be acted upon. APPLICANT SUBMITS ENGINEER FORM 4345 TO DISTRICT OFFICE r PERMIT ISSUED APPLICATION RECEIVED, ACKNOWL- EDGED, AND PROCESSED APPLICANT SIGNS AND RETURNS WITH FEE Figure 39. Overiew of a typical U.S. Army Corps of Engineers review process for Section 404 dredge-and-fill permit request. (Source: Modified from I.A. Kusler, Our National Wetland Heritage: A Protection Guide- book. Copyright (c) 1983 by the Environmental Law Institute. Reprinted with permission.) PUBLIC NOTICE ISSUED APPLICATION APPROVED NORMAL 30-DAY COMMENT PERIOD APPLICATION REVIEWED BY U.S. ARMY CORPS OF ENGINEERS APPLICATION EVALUATED REVIEW AND COMMENT BY APPROPRIATE FEDERAL AND STATE AGENCIES (EPA, FWS, AND OTHERS) APPLICATION DENIED Esthetics Recreation Fish values Land use Wildlife value Economics- Food production * Flood-damage prevention* Safety Conservation 1 Environmental concerns Historic value- PUBLIC HEARING MAY BE HELD National Water Summary Wetland Resources: MANAGEMENT AND RESEARCH 61 If the FWS or NOAA disagree with a permit approved by a District Engineer, they can request that the per- mit be reviewed at a higher level within the Corps. However, the Assistant Secretary of the Army has the unilateral right to refuse all requests for higher level reviews. The Assistant Secretary accepted the addi- tional review of 16 of the 18 requested out of the total 105,000 individual permits issued between 1985 and 1992 (Schley and Winter, 1992). Because many activities may cause the discharge of dredged and fill materials, and the potential effects of these activities differ, the Corps has issued general regulations to deal with a wide range of activities that could require a Section 404 permit. The Corps can forgo individual permit review by issuing general per- mits on a State, regional, or nationwide basis. Gen- eral permits cover specific categories of activities that the Corps determines will have minimal effects on the aquatic environment, including wetlands. General permits are designed to allow activities with minimal effects to begin with little, if any, delay or paperwork. General permits authorize approximately 75,000 ac- tivities annually that might otherwise require a per- mit (U.S. Environmental Protection Agency, 1991); however, most activities in wetlands are not covered by general permits (Morris, 1991). Not all dredge and fill activities require a Section 404 permit. Many activities that cause the discharge of dredged and fill materials are exempt from Section 404. The areas specifically exempted from Section 404 include: normal farming, forestry, and ranching activi- ties; dike, dam, levee, and other navigation and trans- portation structure maintenance; construction of tem- porary sedimentation basins on construction sites; and construction or maintenance of farm roads, forest roads, or temporary roads for moving mining equip- ment (Morris, 1991). In addition, the Corps' flood- control and drainage projects and other Federal projects authorized by Congress and planned, fi- nanced, and constructed by a Federal agency also are exempt from the Section 404 permitting requirements if an adequate environmental impact statement is pre- pared. Not all methods of altering wetlands are regulated by Section 404. Common methods of altering wetlands are listed in table 7. Unregulated methods include: wetland drainage, the lowering of ground-water lev- els in areas adjacent to wetlands, permanent flooding of existing wetlands, deposition of material that is not specifically defined as dredged and fill material by the Clean Water Act, and wetland vegetation removal (Of- fice of Technology Assessment, 1984). State authority over the Federal Section 404 pro- gram is a goal of the Clean Water Act. Assumption of authority from the EPA has been completed only by Michigan and New Jersey. Under this arrangement, the EPA is responsible for approving State assumptions and retains oversight of the State Section 404 program, and the Corps retains the navigable waters permit pro- gram (Mitsch and Gosselink, 1993). States cannot is- sue permits over EPA's objection, but EPA has the au- thority to waive its review for selected categories of permit applications. Few States have chosen to assume the program, in part because few Federal resources are available to assist States and assumption does not in- clude navigable waters (World Wildlife Fund, 1992). The Clean Water Act regulates dredge and fill activities that would adversely affect wetlands. Table 7. Methods of altering wetlands [Source: The Conservation Foundation, 1988, p. 15] PHYSICAL Filling adding any material to raise the bottom level of a wetland or to replace the wetland with dry land Draining removing the water from a wetland by ditching, tiling, pumping, and so forth Excavating dredging and removing soil and vegetation from a wetland Diverting water away preventing the flow of water into a wetland by removing water upstream, lowering lake levels, or lowering ground-water tables ^^^ Clearing removing vegetation by burning, digging, application of herbicide, scraping, mowing, or otherwise cutting Flooding raising water levels, either behind dams, by pumping, or otherwise channeling water into a wetland Diverting or withholding sediment trapping sediment by constructing dams, channels, or other types of projects, thereby inhibiting wetland regeneration in natural deposition areas such as deltas Shading placing pile-supported platforms or bridges over wetlands, causing vegetation to die because of a lack of adequate sunlight Conducting activities in adjacent areas disrupting the interactions between wetlands and adjacent land areas, or incidentally affecting wetlands through activities at adjoining sites CHEMICAL Changing nutrient levels increasing or decreasing nutrient levels within the local water and or soil system, ______________forcing wetland plant community changes___________________________ Introducing toxics adding toxic compounds to a wetland either intentionally (for example, herbicide treatment to reduce vegetation) or unintentionally, adversely affecting wetland plants and animals ' '"- " BIOLOGICAL Grazing consumption and compaction of vegetation by domestic or wild animals Disrupting natural populations reducing populations of existing species, introducing exotic species, or otherwise disturbing resident organisms 62 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES "Swampbuster" removes Federal incentives for the agricultural conversion of wetlands. The Coastal Zone Manage- ment Program provides States with some control over wetland resources. "Swampbuster" The program that seeks to remove Federal incen- tives for the agricultural conversion of wetlands is part of the Food Security Act of 1985 and 1990, and is known as "Swampbuster." Swampbuster renders farm- ers who drained or otherwise converted wetlands for the purpose of planting crops after December 23,1985, ineligible for most Federal farm subsidies. Through Swampbuster, Congress directed the U.S. Department of Agriculture (USDA) to slow wetland conversion by agricultural activities (U.S. Fish and Wildlife Service, 1992). The government programs that Swampbuster specifically affects are listed in Section 1221 of the Food Security Act. If a farmer loses eligibility for USDA programs under Swampbuster, he or she may regain eligibility during the next year simply by not using wetlands for growing crops. Swampbuster is ad- ministered by USDA's Consolidated Farm Service Agency. The NRCS and the FWS serve as technical consultants (World Wildlife Fund, 1992). The Swampbuster was amended by the Food, Agriculture, Conservation, and Trade Act of 1990 to create the Wetland Reserve Program. The Wetland Re- serve Program provides financial incentives to farm- ers to restore and protect wetlands through the use of long-term easements (usually 30-year or permanent). The program provides farmers the opportunity to of- fer a property easement for purchase by the USDA and to recieve cost-share assistance (from 50 to 75 percent) to restore converted wetlands. Landowners make bids to participate in the program. The bids represent the payment they are willing to accept for granting an easement to the Federal Government. The Consoli- dated Farm Service Agency ranks the bids according to the environmental benefit per dollar. Easements require that farmers implement conservation plans approved by the NRCS and the FWS. Enrollment in the pilot program was authorized for nine States. The program's goal is to enroll 1 million acres by 1995 (U.S. Fish and Wildlife Service, 1992). Funding for this program is appropriated annually by Congress (U.S. Army Corps of Engineers, 1994). Because 74 percent of United States' wetlands are on private land, programs that provide incentives for private landown- ers to preserve their wetlands, such as the Wetland Reserve Program, are critical for protecting wetlands (Council of Environmental Quality, 1989). Coastal Wetlands Protection Programs The 1972 Coastal Zone Management Act and the 1982 Coastal Barriers Resources Act protect coastal wetlands. The Coastal Zone Management Act encour- ages States (35 States and territories are eligible, in- cluding the Great Lakes States) to establish voluntary coastal zone management plans under NOAA's Coastal Zone Management Program and provides funds for developing and implementing the plans. The NOAA also provides technical assistance to States for developing and implementing these programs. For Federal approval, the plans must demonstrate enforce- able standards that provide for the conservation and environmentally sound development of coastal re- sources. The program provides States with some con- trol over wetland resources by requiring that Federal activities be consistent with State coastal zone man- agement plans, which can be more stringent than Fed- eral standards (World Wildlife Fund, 1992, p. 87). A State also can require that design changes or mitiga- tion requirements be added to Section 404 permits to be consistent with the State coastal zone management plan. The Coastal Zone Management Act has provided as much as 80 percent of the matching-funds grants to States to develop plans for coastal management that emphasize wetland protection (Mitsch and Gosselink, 1993). Some States pass part of the grants on to local governments. The Act's authorities are limited to wet- lands within a State's coastal zone boundary, the defi- nition of which differs among States. As of 1990, 23 States had federally approved plans. The 1982 Coastal Barriers Resources Act denies Federal subsidies for development within undevel- oped, unprotected coastal barrier areas, including wetlands, designated as part of the Coastal Barrier Resources System. Congress designates areas for in- clusion in the Coastal Barriers Resource System on the basis of some of the following criteria (Watzin, 1990): Size Development status Composition Wind, wave, and tidal energies Associated aquatic habitat, including adjacent wetlands In addition, States, local governments, and con- servation organizations owning lands that were "oth- erwise protected" could have their lands added to this system until May 1992. ("Otherwise protected" lands are areas within undeveloped coastal barriers that were already under some form of protection.) Once in the Coastal Barriers Resources System, these areas are rendered ineligible for almost all Federal financial subsidies for programs that might encourage develop- ment. In particular, these lands no longer qualify for Federal flood insurance, which discourages develop- ment because coastal lands are frequently subject to flooding and damage from hurricanes and other storms. The FWS is responsible for mapping these areas and approves lands to be included in the system. The purposes of the Coastal Barrier Resources Act are to minimize the loss of human life, to reduce damage to fish and wildlife habitats and other valuable re- sources, and to reduce wasteful expenditure of Fed- eral revenues (Watzin, 1990). In the future, eligible surplus government land will be included if approved by the FWS. About 95 percent of the 788,000 acres added to the system in 1990 along the Atlantic and Gulf coasts consists of coastal wetlands and near-shore waters (World Wildlife Fund, 1992). Flood-Plain and Wetland Protection Orders Executive Orders 11988, Floodplain Manage- ment, and 11990, Protection of Wetlands, were signed by President Carter in 1977. The purpose of these Executive Orders was to ensure protection and proper management of flood plains and wetlands by Federal agencies. The Executive Orders require Federal agen- cies to consider the direct and indirect adverse effects of their activities on flood plains and wetlands. This requirement extends to any Federal action within a flood plain or a wetland except for routine mainte- National Water Summary Wetland Resources: MANAGEMENT AND RESEARCH 63 nance of existing Federal facilities and structures. The Clinton administration has proposed revising Execu- tive Order 11990 to direct Federal agencies to consider wetland protection and restoration planning in the larger scale watershed/ecosystem context. WETLAND DELINEATION STANDARDS The Corps published, in 1987, the Corps of En- gineers Wetland Delineation Manual, a technical manual that provides guidance to Federal agencies about how to use wetland field indicators to identify and delineate wetland boundaries (U.S. Army Corps of Engineers, 1987). In January of 1989, the EPA, Corps, SCS, and FWS adopted a single manual for de- lineating wetlands under the Section 404 and Swampbuster programs The Federal Manual for Identifying and Delineating Jurixdictional Wetlands (commonly referred to as the "1989 Manual"). The "1989 Manual" establishes a national standard for identifying and delineating wetlands by specifying the technical criteria used to determine the presence of the three wetland characteristics: wetland hydrology, wa- ter-dependent vegetation, and soils that have devel- oped under anaerobic conditions (U.S. Environmen- tal Protection Agency, 1991). In 1991, the President's Council on Competitive- ness proposed revisions to the 1989 Manual because of some concern that nonwetland areas were regularly being classified as wetlands (Environmental Law Re- porter, 1992a). The proposed 1991 Manual was char- acterized by many wetland scientists as politically based rather than scientifically based. In September of 1992, Congress authorized the National Academy of Science to conduct a $400,000 study of the meth- ods used to identify and delineate wetlands (Environ- mental Law Reporter, 1992b). On August 25, 1993, the Clinton administration's wetland policy, pro- claimed that, "Federal wetlands policy should be based upon the best science available" (White House Office of Environmental Policy, 1993) and the 1987 Corps Manual is the sole delineation manual for the Federal Government until the National Academy of Sciences completes its study (White House Office of Environmental Policy, 1993). MITIGATION Mitigation is the attempt to alleviate some or all of the detrimental effects arising from a given action. Wetland mitigation replaces an existing wetland or its functions by creating a new wetland, restoring a former wetland, or enhancing or preserving an exist- ing wetland. This is done to compensate for the au- thorized destruction of the existing wetland. Mitiga- tion commonly is required as a condition for receiv- ing a permit to develop a wetland. Wetland mitigation can be conducted directly on a case-by-case onsite basis, or through a banking sys- tem, Onsite mitigation requires that a developer cre- ate a wetland as close as possible to the site where a wetland is to be destroyed. This usually involves a one- to-one replacement. A mitigation bank is a designated wetland that is created, restored, or enhanced to compensate for fu- ture wetland loss through development. It may be and usually is located somewhere other than near the site to be destroyed and built by someone other than the developer. The currency of a mitigation bank is the mitigation credit. "Mitigation banks require systems for valuing the compensation credits produced and for determining the type and number of credits needed as compensation for any particular project. ***Mitiga- tion bank credit definitions are an attempt to identify those features [of wetland] which allow reasonable ap- proximations of replacement" (U.S. Army Corps of Engineers, 1994, p. 63). Wetland evaluation methods have been developed or are being developed to address the problem of evaluating two different wetlands so that the degradation of one can be offset by the resto- ration, enhancement, or creation of the other and to assign either a qualitative or quantitative value to each wetland. When buying the credits, developers pay a proportionate cost toward acquiring, restoring, main- taining, enhancing, and monitoring the mitigation bank wetland. Banks cover their costs by selling cred- its to those who develop wetlands, or by receiving a taxpayer subsidy. Several problems are associated with wetland mitigation. The concept of wetland compensation may actually encourage destruction of natural wetlands if people believe that wetlands can be easily replaced. A 1990 Florida Department of Environmental Regula- tion study examined the success of wetland creation projects and found that the success rate of created tidal wetlands was 45 percent, whereas the success rate for created freshwater wetlands was only 12 percent. (Redmond, 1992). Figure 40 shows the relative success of wetland mitigation projects overall in south Florida. The apparent factor controlling the lower success rate for freshwater wetlands was the difficulty in duplicat- ing wetland hydrology, that is, water-table fluctua- tions, frequency and seasonality of flooding, and ground-water/surface-water interactions. A study of wetland mitigation practices in eight States revealed that in most of the States, more wet- land acreage was destroyed than was required to be created or restored, resulting in a net loss of acreage when mitigation was included in a wetlands permit (Kentula and others, 1992). Less than 55 percent of the permits included monitoring of the project by site visit. A limited amount of information exists about the number of acres of wetlands affected by mitigation or the effectiveness of particular mitigation techniques because of the lack of followup. Several studies in Rorida reported that as many as 60 percent of the re- quired mitigation projects were never even started (Lewis, 1992). In addition, the mitigation wetland commonly was not the same type of wetland that was destroyed, which resulted in a net loss of some wet- land types. (See article "Wetland Restoration and Cre- ation" in this volume.) RECENT PRESIDENTIAL WETLAND PROTECTION INITIATIVES In his 1988 Presidential address and in his 1990 budget address to Congress, President Bush echoed the recommendations of the National Wetland Policy Forum. The Forum was convened in 1987 by the Con- servation Foundation at the request of EPA. The short- H Federal wetlands policy should be based upon the best science available." 15 p a3 10 cc Q. li. O CC EXPLANATION EH] All goals met EPl Some goals met r~l Few goals met B Incomplete Figure 40. Status of 40 wetland mitigation projects in south Florida. The average age of the projects was less than 3 years. (Source: Modified from Mitsch and Gosselink, 1993.) 64 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES "No nef loss" of wetlands is a national goal. term recommendation of the forum was to decrease wetland losses and increase wetland restoration and creation the concept of "no net loss" as a national goal. This implied that when wetland loss was un- avoidable, creation and restoration should replace de- stroyed wetlands (Mitsch and Gosselink, 1993). On August 25, 1993, President Clinton unveiled his new policy for managing America's wetland re- sources. The program was developed by the Inter- agency Working Group on Federal Wetlands Policy, a group chaired by the White House Office on Environ- mental Policy with participants from the EPA, the Corps, the Office of Management and Budget, and the Departments of Agriculture, Commerce, Energy, In- terior, Justice, and Transportation. The Admin- istration's proposals mix measures that tighten restric- tions on activities affecting wetlands in some cases and relax restrictions in other areas. The Clinton policy en- dorses the goal of "no net loss" of wetlands; however, it clearly refers to "no net loss" of wetland acreage rather than "no net loss" of wetland functions. The President's wetland proposal would expand Federal authority under the Section 404 program to regulate the draining of wetlands in addition to regu- lating dredging and filling of wetlands. Other proposed changes to the Federal permitting program include the requirement that most Section 404 permit applications be approved or disapproved within 90 days, and the addition of an appeal process for applicants whose permits are denied. The EPA and the Corps are di- rected to relax regulatory restrictions that cause only minor adverse effects to wetlands such as activities affecting very small areas. The Clinton policy calls for avoiding future wet- land losses by incorporating wetland protection into State and local government watershed-management planning. This new policy also significantly expands the use of mitigation banks to compensate for feder- ally approved wetland development or loss. Clinton's proposals relaxed some of the current restrictions on agricultural effects on wetlands and in- creased funding for incentives to preserve and restore wetlands on agricultural lands. The administration policy excluded 53 million acres of "prior converted croplands" from regulation as wetlands. Also, author- ity over wetland programs affecting agriculture was shifted from the FWS to the NRCS and proposed in- creased funding for the Wetlands Reserve Program, which pays farmers to preserve and restore wetlands on their property. References Cited Conservation Foundation, 1988, Protecting America's wet- lands An action agenda: Washington, D.C., The Con- servation Foundation, p. 15. Council of Environmental Quality, 1989, Environmental trends: Washington, D.C., Office of the President, Coun- cil of Environmental Quality, p. 152. Environmental Law Reporter, 1992a, Agencies working to resolve controversy, official says: Washington, D.C., Bureau of National Affairs, v. 23, no. 13, p. 924. ____1992b, Reilly favors return to 1987 manual, cites emerging consensus on delineation: Washington, D.C., Bureau of National Affairs, v. 23, no. 17, p. 1,260. Kentula, Mary, Sifneos, Jean, Brooks, Robert, Gwin, Stephanie, Holland, Cindy, and Sherman, Arthur, 1992, An approach to decisionmaking in wetland restoration and creation: U.S. Environmental Protection Agency, EPA/600/R-92/150,151 p. Kusler, J.A., 1983, Our national wetland heritage A pro- tection guidebook: Washington, D.C., Environmental Law Institute, p. 62. Lewis, Roy, 1992, Why Florida needs mitigation banking: National Wetlands Newsletter, v. 14, no. 1, p. 7. Mitsch, W.J., and Gosselink, J.G., 1993, Wetlands: New York, Van Nostrand Reinhold Company, 722 p. Morris, Marya, 1991, Wetland protection A local govern- ment handbook: Chicago, 111., American Planning As- sociation, 31 p. Office of Technology Assessment, 1984, Wetlands Their use and regulation: Washington, D.C., OTA-0 206, p. 168-169. Redmond, Ann, 1992, How successful is mitigation?: Wash- ington, D.C., National Wetlands Newsletter, v. 14, no. 1, p. 5-6. Schley, Terry, and Winter, Linda, 1992, New 404(q) MOA diluting EPA's role: Washington, D.C., National Wetlands Newsletter, Environmental Law Institute, v. 14, no. 6, p. 8. U.S. Army Corps of Engineers, 1987, Corps of Engineers wet- lands delineation manual: Vicksburg, Miss., U.S. Army Corps of Engineers Technical Report Y-87-1, p. 1. ____1994, National wetland mitigation banking study Wetland mitigation banking: Washington, D.C., Environ- mental Law Institute, IWR Report 94-WMB-6, 178 p. U.S. Environmental Protection Agency, 1991, Proposed re- visions to the Federal manual for delineating wetlands: Washington, D.C., Office of Wetlands, Oceans, and Wa- tersheds, p. 1-4. U.S. Fish and Wildlife Service, 1992, Digest of Federal re- source laws of interest to the U.S. Fish and Wildlife Ser- vice: Washington, D.C., U.S. Fish and Wildlife Service, Office of Legislative Services, p. 26. Want, William, 1993, Law of wetlands regulation: Deerfield, 111., Clark Boardman Callaghan, p. 13-2. Watzin, M.C., 1990, Coastal Barrier Resources System map- ping process, in Federal coastal wetland mapping pro- gram: Washington, D.C., U.S. Fish and Wildlife Service Biological Report 90 (18), p. 21-26. White House Office of Environmental Policy, 1993, Protect- ing America's wetlands A fair, flexible, and effective approach: the White House, Office of Environmental Policy, p. 15. World Wildlife Fund, 1992, Statewide wetlands strategies A guide to protecting and managing the resource: Wash- ington, D.C., Island Press, 268 p. FOR ADDITIONAL INFORMATION: Todd H. Votteler, 4312 Larchmont Avenue, Dallas, TX 75205; Thomas A. Muir, U.S. Geological Survey, 413 National Center, Reston, VA 22092 U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources: MANAGEMENT AND RESEARCH 65 Wetland Management and Research Wetland Research by Federal Agencies By Richard E. Coleman 1 , Edward T. LaRoe2, and Russell F. Theriot' Because wetlands were drained and filled for farming and building purposes during the last several hundred years, more than half of the original wetlands in the United States have been lost (Prayer and oth- ers, 1983). Only during the last quarter century has society begun to understand the value of wetlands and the particular benefits that they provide. (See the ar- ticle "History of Wetlands in the Conterminous Uni- ted States" in this volume.) This understanding has been broadened by the concerted efforts of many public and private researchers. This article addresses the research contributions of Federal agencies: which agencies are involved in wetland research, why they are involved, and the nature of their research. In an effort to develop a strategy for preventing the further loss of wetlands, the Committee on Earth and Environmental Sciences established a Wetlands Research Subcommittee to determine the status of wetland research being conducted by Federal agen- cies. These efforts resulted in an unpublished report that presented a national inventory and data base of ongoing research and addressed future research needs (Wetlands Research Subcommittee, unpub. data, 1992). Data presented in the following few pages are drawn largely from these findings. During 1992, Federal wetland research expendi- tures were about $63 million. A total Federal invest- ment of more than $250 million is distributed over the lifetime of the existing projects. The amount of Fed- eral research spending per State is depicted in figure 41. THE REASONS FOR FEDERAL INVOLVEMENT IN WETLAND RESEARCH Scientists from many organizations, including those in the private sector, those from colleges and universities, and those from public institutions, are engaged in wetland research. Typically, each organi- zation has its own reasons for being involved in wet- land research. Federal wetland research may be done because it is part of an agency's mission, is part of an agency's responsibilities as outlined by the Congress, or is otherwise in the national interest. When research is mission oriented, it is part of the basic work of an agency. Mission-oriented Fed- eral agency wetland research generally is done for one of five reasons: 1. Ownership The agency owns and is responsible for managing wetlands. The agency is the stew- ard of its land. 2. Public trust responsibilities An agency may be responsible for ensuring the long-term survival of certain fish and other wildlife resources, which are EXPLANATION il , Contributing research Not directly related to wetlands O S Focused research "2 |_ Directly related to wetlands Figure 41 . Cost of Federal agency wetland research, per State, during fiscal year 1992. (Source: Federal Wetlands Research Inventory and Database, unpub. data, 1992; compiled by the Wetlands Research and Technology Center, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Miss.) 1 U.S. Army Corps of Engineers. 2 National Biological Service. 66 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES The understanding of wetlands as a valued resource has been broadened by the concerted efforts of many public and private researchers. held in trust for the public. Wetlands form critical habitat and are part of the ecological system on which many of these species depend. 3. Regulatory responsibilities Because wetlands provide so many benefits to society, activities that adversely affect them may be subject to regula- tion. Some agencies, therefore, have regulatory authority over wetlands. 4. Development activities Federal agencies have an obligation to avoid projects or actions that may adversely affect wetlands, to minimize the nega- tive effects of their activities on wetlands, and to mitigate unavoidable wetland losses. These re- quirements apply to all Federal agencies, but those regularly involved in large-scale develop- ment projects support specific wetland research activities. 5. Science Agencies that have missions directly re- lated to science may conduct or support research on wetlands. Although many different levels of government may have mission-oriented research, Federal agency wetland research activities relate to congressionally mandated responsibilities. Most significant among these are provisions that relate to: Interstate commerce Wetlands are part of the en- tire physical landscape, from river headwaters to the sea. They form parts of water bodies that pro- vide shipping, transportation, and navigation. Some wetlands are used as routes for trade in in- terstate commerce, and wetland products are used in interstate trade. What happens to wet- lands in one State can affect wetland activities, benefits, and uses in another State. International treaties The benefits and uses of wetlands are the subject of international treaties, such as the Ramsar Convention of 1971 and the Migratory Bird Treaty, which are the exclusive domain of the Federal Government. International efforts that result from those treaties, such as ef- forts between Canada, Mexico, and the United States to restore declining wetland-dependent waterfowl populations, have an essential Federal element. (See article "Wetlands as Bird Habitat" in this volume.) There is also an intrinsic national interest in wet- land research. Where wetland questions or issues are widespread or shared by jurisdictions, or affect the national health, safety, or welfare. Congress may de- termine that there is a national interest that justifies Federal agency research. TYPES OF FEDERAL WETLAND RESEARCH The Federal Wetlands Research Inventory and Database reported in 1992 that 18 Federal agencies were conducting some wetland research (Wetlands Research Subcommittee, unpub. data, 1992). Two types of research were included in the inventory focused and contributing. Focused research is spe- cifically designed to investigate wetlands or some component thereof; contributing research provides some information about wetlands but is not directly related to wetlands. Research categories also were identified by the Inventory and Database. These categories were de- fined by the subject of the wetland research being conducted, and were listed in five topical areas: 1. Wetland processes Research to address factors that affect the type, location, size, and functions of wetlands. 2. Wetland functions Research to determine the role wetlands play and the benefits they provide. 3. Human-induced stresses Research to improve ways of detecting or quantifying the effects of Delineation and Identification 5 percent AGENCY Army Corps of Engineers Corps Agricultural Research Service ARS Bureau of Mines BOM Bureau of Reclamation BOR Department of Energy DOE Federal Highway Administration FHA Minerals Management Service MMS National Oceanic and NOAA Atmospheric Administration National Park Service NPS National Science Foundation NSF Office of Surface Mining OSM Smithsonian Institute SMI Soil Conservation Service* SCS Tennessee Valley Authority TVA U.S. Environmental Protection Agency EPA U.S. Fish and Wildlife Service FWS U.S. Forest Service USFS U.S. Geological Survey USGS RESEARCH CATEGORY PROCESSES $ 1,072,000 814,000 316,000 25,000 2,698,000 77,000 500,000 287,000 1,046,000 269,000 0 847,000 32,000 55,000 150,000 2,366,000 213,000 6,534,000 FUNCTIONS $ 438,000 0 49,000 25,000 2,126,000 39,000 0 2,144,000 0 0 0 100,000 0 167,000 586,000 1,027,000 409,000 844,000 HUMAN- INDUCED STRESSES $ 154,000 65,000 0 0 2,195,000 29,000 0 523,000 194,000 0 0 32,000 0 70,000 0 7,039,000 13,000 3,456,000 DELINEATION AND IDENTIFICATION $ 364,000 0 0 0 1,279,000 347,000 0 100,000 0 0 0 88,000 0 0 0 771,000 0 118,000 MANAGEMENT $ 4,818,000 909,000 0 150,000 2,110,000 100,000 0 165,000 531,000 0 147,000 1,000 2,014,000 2,674,000 2,320,000 4,916,000 412,000 1,567,000 * Became the Natural Resources Conservation Service in 1994. Figure 42. Summary of Federal agency wetland research expenditures by research category during 1992. (Source: Federal Wetlands Research Inventory and Database, unpub. data, 1992; compiled by the Wetlands Research and Technology Center, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Miss.) National Water Summary Wetland Resources: MANAGEMENT AND RESEARCH 67 stress on wetlands, or of determining stress thresh- olds of wetlands. 4. Wetland delineation and identification Research on methods and techniques to identify wetlands and delineate wetland boundaries. 5. Management Research to develop tools and tech- nologies to maintain, restore, and construct wet- lands. Figure 42 depicts the expenditures on Federal re- search in each of these categories in 1992. Individual research studies may span several of these categories; however, these categories represent a convenient way to describe existing research activities. In addition to distinguishing the type of research, it also is useful to distinguish the type of wetland being studied. Because ecological processes and functions differ with the type of wetland, research needs and techniques also differ. Disappearing coastal and bottom-land hardwood wetlands are among the major areas of research. Figure 43 shows Federal ex- penditures forresearch on different types of wetlands. (See article "Wetland Definitions and Classification in the Conterminous United States" for an explana- tion of wetland types.) AGENCY ROLES AND RESPONSIBILITIES Federal wetland research is conducted through- out the Nation. Twelve agencies listed in the Wetland Research Subcommittee's report and discussed below have wetland research expenditures of $1 million or more. Although not discussed below, other agencies with less funding that also contribute to wetland re- search are the Department of the Interior's Bureau of Mines, Bureau of Reclamation, Minerals Manage- ment Service, and Office of Surface Mining; the Fed- eral Highway Administration's Department of Trans- portation: and the National Science Foundation. Department of the Interior Wetland research activities in the Department of the Interior relate to its responsibilities as the primary steward of America's natural resources. The Depart- ment of the Interior performs basic scientific research on wetland processes and functions and applied fo- cused research on human-induced stresses, delinea- tion and identification, and management of wetlands. The Department assumes ownership and management responsibilities for wetlands through the U.S. Fish and Wildlife Service (FWS) and the National Park Ser- vice, and scientific research responsibilities through the activities of the U.S. Geological Survey (USGS) and the National Biological Service (NBS). Research funding for the Department was greater than $30.5 million in 1992 (figs. 42-43). U.S. Fish and Wildlife Service: The FWS has stewardship responsibilities for fish and other wild- life (such as migratory birds, anadromous fish, and endangered species), their habitats, and for wildlife refuges. As a major Federal landowner, the FWS pro- tects and manages wetlands and associated habitats on more than 90 million acres of national wildlife refuges and provides advice about and technical sup- port for regulatory activities and trust species to other Federal, State, and private landowners. The FWS, through the National Wetlands Inventory program, provides detailed wetland maps for the Nation, and also reports to Congress every 10 years the status and trends of the Nation's wetlands. (See article "Wetland Mapping and Inventory" in this volume.) Research fo- cuses on improved methods and tools for identifying and delineating different wetland types. U.S. Geological Survey: The USGS provides geo- logic, hydrologic, and topographic information to assist Federal, State, and local governments, the pri- vate sector, and individual citizens in making man- agement decisions about the use of land and water What happen* to wetlands in one State can affect wetland activities, benefits, and uses in another State. AGENCY Army Corps of Engineers Corps Agricultural Research Service ARS Bureau of Mines BOM Bureau of Reclamation BOR Department of Energy DOE Federal Highway Administration FHA Minerals Management Service MMS National Oceanic and MOAA Atmospheric Administration NUAA National Park Service NFS National Science Foundation NSF Office of Surface Mining OSM Smithsonian Institute SMI Soil Conservation Service SCS Tennessee Valley Authority TVA U.S. Environmental Protection Agency ERA U.S. Fish and Wildlife Service FWS U.S. Forest Service USFS U.S. Geological Survey USGS MARINE S 0 0 0 0 153,000 5,000 250,000 193,000 7,000 0 0 420,000 184,000 0 150,000 428,000 0 1,482,000 W ESTUARINE $ 1,750,000 20,000 0 0 418,000 5,000 250,000 2,925,000 818,000 170,000 0 355,000 806,000 0 225,000 2,949,000 0 3,587,000 ETLAND TYPES RIVERINE $ 1,529,000 1,053,000 0 50,000 1,855,000 2,000 0 66,000 428,000 13,000 0 267,000 323,000 84,000 736,000 5,202,000 102,000 2,606,000 * PALUSTRINE $ 2,036,000 650,000 0 50,000 2,640,000 193,000 0 35,000 480,000 86,000 64,000 26,000 352,000 531,000 1,421,000 4,033,000 945,000 2,880,000 LACUSTRINE $ 824,000 65,000 0 100,000 406,000 0 0 0 58,000 0 0 0 268,000 2,084,000 270,000 3,564,000 0 1,963,000 * Descrepancies in total expenditures occur because some agencies did not include constructed wetlands when reporting these figures. Figure 43. Summary of Federal agency wetland research expenditures by wetland type during 1992. (Sources: Federal Wetlands Research Inventory and Database, unpub. data, 1992; compiled by the Wetlands Research and Technology Center, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Miss.) 68 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Core sample being collected by the U.S. Geological Survey at a fen in Minn., tells the sediment history of this particular wetland. (Photograph by Nancy Rybicki, U.S. Geological Survey.) The National Biological Service collects turtlegrass near Chan- deleur Islands, La., to study the effects of water quality on the plant. (Photograph courtesy of The National Biological Service.) The National Biological Service collects bulltongue in a marsh near Lake Salvador, La., for use in greenhouse experiments in salinity and flooding tolerance. (Photograph courtesy of The National Biological Service.) resources. The USGS's wetland research activities are an important part of the agency's activities. Research focuses on the geology, chemistry, hydrology, and bi- ology of wetlands and their interactions. Studies are conducted in selected wetlands to determine the pro- cesses responsible for the formation and evolution of wetlands and to increase understanding of wetland functions. Some specific topics that hydrologic stud- ies address are ground-water/surface-water interac- tions; the role of wetlands in water-quality improve- ment; the relation between flood-plain wetlands, riv- erine and estuarine hydrology, and water quality; and the relation of light and water chemistry to aquatic plant distribution in tidal waters. National Park Service: Wetland research by the National Park Service is primarily issue driven; it is management-oriented and focuses on protecting re- sources, mitigating the effects of human actions on wetlands, and restoring natural wetland functions where they have been disturbed by past or ongoing human activities. National Biological Service: The NBS was estab- lished in October 1993 and, therefore, was not in- cluded in the report by the Wetland Research Sub- committee and not included in the graphs in figures 42-43. However, it is a large player in research being done on wetlands and, therefore, is included in this discussion. The NBS inventories and monitors wet- lands and conducts biological research on many aspects of wetlands; in fact, most activities of the NBS are wetland related. It provides biological information and research support to management agencies within the Federal Government. Department of Energy The Department of Energy's role in and respon- sibilities toward wetland research are related to its compliance with environmental regulations. The Department does this by assessing the environmen- tal effects of its activities on lands, including wet- lands, under its jurisdiction, and by operating and developing facilities in ways that maintain and en- hance environmental quality while providing efficient energy production, transmission, and use. Research focuses on supporting these activities. Research fund- ing was about $10.3 million in 1992 (figs. 42^3). Department of Defense Wetland research activities of the Department of Defense result primarily from legislation pertaining to the mission of the U.S. Army Corps of Engineers (Corps). The Army, through the Corps, is assigned responsibility for much of the Nation's water-re- source development activities, including efforts to protect, conserve, restore, and establish new wet- lands. In performing its development mission, such as keeping waterways open by dredging or building levees to protect cities from flooding, the Corps di- rectly affects wetlands and must consider the effects of its activities. The Corps has established a formal Wetlands Research Program to support its wetland- related responsibilities. This program is designed to include both basic and applied research that empha- size the Corps strengths in engineering design and National Water Summary Wetland Resources: MANAGEMENT AND RESEARCH construction, stewardship, and management. Re- search funding for the Corps in 1992 was about $6.5 million (figs. 42-43). Department of Agriculture The Department of Agriculture performs wetland research through several of its agencies; the Natural Resources Conservation Service (formerly known as the Soil Conservation Service), the Agricultural Re- search Service, and the U.S. Forest Service. Research funding for the Department of Agriculture was about $4.5 million in 1992 (figs. 42^3). Natural Resources Conservation Service: The Natural Resources Conservation Service assists other Federal, State, and local governments in resource conservation activities that include wetland protec- tion. Their authority covers mainly lands with high potential for conversion to agricultural uses. The Natural Resources Conservation Service's plant materials centers develop new varieties of plants and the technology for using plants to solve soil and water-conservation problems. They also provide for the commercial production of these plants. Some of the centers conduct investigations on how to reestab- lish marsh vegetation along eroding tidal shores in the mid-Atlantic States and the Gulf Coast States from Alabama to Mexico. Projects are underway at other centers to develop new varieties of plants and encour- age plant reproduction, to develop techniques for es- tablishing and maintaining restored and created fresh- water wetlands, and to design and construct wetlands that act as biological filters of agricultural runoff. Economic Research Service: Although the Eco- nomic Research Service is not one of the agencies listed in the Wetland Research Subcommittee report, its research is integral to oversight of the Wetland Reserve Program by the Natural Resources Conser- vation Service (see the article "Wetland Protection Legislation" in this volume), and is, therefore, men- tioned in this discussion. The Economic Research Service conducts cost and benefit comparison stud- ies to determine effective economic incentives asso- ciated with wetland conservation or destruction. Because the Wetland Reserve Program is voluntary, research focuses on identifying costs that limit farm- ers' participation. Agricultural Research Service: The Agricultural Research Service's mission includes development of technology needed to ensure maintenance of environ- mental quality and natural resources. Their research supports implementation of Federal agricultural leg- islation and development of new agricultural practices that produce less off-site contamination. Many pro- grams indirectly contribute to national wetland goals by improving management of basins that drain into wetlands. U.S. Forest Service: The U.S. Forest Service con- ducts research to support improved management of Federal, State, and private forests; the research com- prises efforts to describe ecosystem dynamics and to develop improved technology for restoring and reha- bilitating forested wetlands. Research is conducted on the role of flowing water in sustaining chemical, physical, and biological processes integral to the func- tioning of wetland and riparian ecosystems. The For- The U.S. Army Corps of Engineers collects water-level data at a bottom-land hardwood wetland located along the Cache River, Ark. (Photograph courtesy of the U.S. Army Corps of Engineers.) The U.S. Army Corps of Engineers dewatered this freshwater wetland at a restoration site at Kenilworth Marsh in Maryland to facilitate planting. Dewatering was achieved by building temporary dikes made from water-filled tubes designed by the Corps for this purpose. (Photograph courtesy of the U.S. Army Corps of Engineers.) est Service also conducts studies of technological improvements used for reforesting wetland and ripar- ian sites, which involves understanding how tree spe- cies adapt to flooding. Other areas of study include establishing understory vegetation, restoring wetland hydrology, and rehabilitating fish and other wildlife habitat. Department of Commerce The Department of Commerce conducts its re- search through the National Oceanic and Atmospheric Administration. In 1992, funding for research by the Department was about $3 million (figs. 42-43). National Oceanic and Atmospheric Administra- tion: The National Oceanic and Atmospheric 70 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES National Marine Fisheries Service scientists study the effects of oyster- shell reefs on sedimentation and use by marine organisms in this created wetland at Swansboro Marsh, N.C. (Photograph by David L. Meyer, National Marine Fisheries Service.) The information derived from broad-scope, individual agency research may complement that of other agencies. Administration's (NOAA) mission is to manage our ocean and coastal resources, describe and predict changes in the Earth's oceans and atmosphere, and promote its global stewardship through scientific re- search and service. Three of NOAA's five organiza- tions are directly involved in wetland research: the National Marine Fisheries Service, the National Ocean Service, and the Office of Oceanic and Atmo- spheric Research. NOAA also has a relevant agency- wide program, the Coastal Ocean Program, which supports management of the coastal ocean environ- ment. The Coastal Ocean Program is intended to pro- vide scientific products that support coastal ocean management through improved understanding and prediction of environmental quality, fishery re- sources, and coastal hazards. One of the Coastal Ocean Program's component programs seeks to un- derstand and quantify the relation between estuarine habitat and coastal ocean productivity. Initial re- National Marine Fisheries Service scientists, using a drop sampler, collect aquatic organisms in a salt marsh on Calveston Island, Tex. This is often done to assess damages following an oil spill. (Photograph by Lawrence P. Rozas, National Marine Fisheries Service.) search has been focused on locating and determin- ing rates of loss of seagrasses, emergent marshes, and adjacent uplands using satellite and aerial photogra- phy. Research is being conducted on the functional attributes of these habitats and their capability of be- ing restored. National Marine Fisheries Service: This or- ganization is the Federal steward of the Nation's living marine resources, from 200 miles offshore (the sea- ward extent of the Nation's assessment of mineral and energy sources) to the freshwater tributaries used by anadromous species for spawning. National Marine Fisheries Service's scientists conduct basic and ap- plied research to advance understanding of wetland habitat functioning in response to natural and human- induced environmental changes, to develop improved techniques for habitat restoration and assessment, and to support the habitat permit review process. The Na- tional Marine Fisheries Service's Restoration Center develops and implements habitat restoration plans that seek to restore, replace, or acquire the equiva- lent of the resources determined to have been injured by releases of oil or hazardous substances to the en- vironment. National Ocean Service: This organization ad- ministers programs that provide support for manag- ing marine environments. It manages a national net- work of marine sanctuaries and estuarine research reserves. The estuarine research reserves, throughout the National Estuarine Research Reserves System, are established, managed, and maintained with the help of State authorities to assure their long-term protec- tion. Research activities are used to facilitate manage- ment of wetlands. Priorities change biennially and have included nonpoint-source pollution (1993-94) and habitat restoration (1994-95). Office of Oceanic and Atmospheric Research: This organization is responsible for conducting research that improves understanding and prediction of oceanic and atmospheric conditions. This includes investigating processes that regulate wetland ecosys- tem structure and production, the responses of these systems to natural and human-induced conditions, and the effects of global climate and other atmospheric conditions on marine resources and ecosystems. U.S. Environmental Protection Agency Research needs within the U.S. Environmental Protection Agency (EPA) are extensive. The Wetlands Research Program of the EPA is an applied research program that primarily provides technical support to improve the Agency's ability to carry out its regula- tory responsibilities. Three components of the Wet- lands Research Program are the Wetland Function Project, the Characterization and Restoration Project, and the Landscape Function Project. Detailed stud- ies of individual wetlands conducted to understand better the processes within wetlands that contribute to wetland functions and wetland responses to envi- ronmental stressors are carried out through the Wet- land Function Project. Studies of the characteristics of groups of wetlands that compare the functions of natural, restored, and created wetlands within similar geographic settings are carried out through the Char- acterization and Restoration Project. Research is con- National Water Summary Wetland Resources: MANAGEMENT AND RESEARCH 71 ducted on the interactions of wetlands with other eco- systems and on the cumulative effects of human ac- tivities on wetland functions through the Landscape Function Project. In 1992, EPA's funding for wetland research was about $3 million (figs. 42^13). Tennessee Valley Authority The Tennessee Valley Authority (TVA) is a re- source management agency created by the Tennessee Valley Authority Act of 1933. Its research focuses on both natural and constructed wetlands. Natural-wet- lands research is directed toward protecting and en- hancing aquatic bed, emergent, and riparian forested wetlands and the wildlife populations dependent on them. Constructed-wetlands research is directed to- ward designing and operating constructed wetlands to solve specific waste-management or environmental problems and examining the basic mechanics and physiology of these systems. Wetland research is con- ducted in the field, in laboratories, and at a unique 32- celled physical model at a constructed-wetland re- search facility in Muscle Shoals, Ala. In 1992, fund- ing for research was about $3 million (figs. 42^3). Smithsonian Institution Smithsonian research on wetlands is focused on the biota, hydrology, and functions of wetlands. Aerial photographs, remote sensing, and Geographic Infor- mation Systems are used to extend research results from specific sites to larger regions and to relate wetlands to their drainage basins. Research support comes directly from Congress, from Smithsonian trust funds, and from extramural grants and contracts. Funding for research in 1992 was about $1 million (figs. 42^3). COORDINATION OF RESEARCH AMONG FEDERAL AGENCIES Federal agencies conduct wetland research to execute their congressionally mandated missions. Generally these research efforts fall within well-de- fined limits. By necessity, some agencies conduct research with a broad range of activities. The infor- mation derived from broad-scope, individual agency research may complement that of other agencies. Federal agencies have special obligations, as stew- ards of public monies, to get the most out of research dollars. Effective coordination is essential to assure that agencies efficiently budget and use research funds, to ensure that research is not duplicated by two or more agencies (and money wasted), and to ensure that the "best science" is achieved. Federal agencies involved in wetland research use formal and informal coordi- nation mechanisms to achieve these goals. Informal coordination takes many forms. It in- cludes scientists from each agency communicating di- rectly with scientists in other agencies about matters of common interest. It also includes many adhoc com- mittees and working groups organized to accomplish general coordination as well as specific research ob- jectives. Among the adhoc committees is the Federal Interagency Coordination Committee on Wetlands Local teachers work in cooperation with U.S. Environmental Protection Agency scientists to measure elevations and create site maps on this restored wetland in Portland, Oreg. (Photograph courtesy of the U.S. Environmental Protection Agency.) Research and Development, a voluntary group that meets annually in Washington, D.C., to present the status of agency research programs and discuss areas of potential interaction. This Committee developed the first National Summary of Ongoing Wetlands Re- search by Federal Agencies (U.S. Army Engineer Waterways Experiment Station, 1992). All Federal agencies that perform wetland research are invited to these meetings. Another voluntary adhoc committee, the Forested Wetlands Research and Development In- teragency Coordination Committee, formed working groups and developed a multiyear interagency re- search proposal for work in forested wetlands in Southern States. The Corps, the NBS, and the FWS provide funds for this research; and the EPA, Agricul- tural Research Service, and Natural Resources Con- servation Service actually do the research. Federal agencies also use informal scientific re- views of individual projects and entire programs for coordination. The purpose of these reviews is to ex- pose a project or program to external review and com- ment, as well as to provide a forum for exchanging views and ideas about each participating agency's project or program. The wetland research programs operated by the Corps, FWS, and EPA, and projects of the NBS's National Wetland Research Center and Cooperative Research Units Center regularly receive external peer review. Several Federal agencies regu- larly hold interagency planning meetings to discuss new wetland research goals and projects, solicit com- ments, and explore areas for potential partnerships and cooperation. Agencies with responsibilities for regulating and managing Federal lands, which include wetlands, conduct workshops, seminars, and other informal meetings to facilitate effective interaction and coor- dination of their research. Professional societies, sci- entific literature, agency publications, newsletters, bulletins, and topical conferences also offer mecha- nisms for coordination and information exchange. More formal coordination is achieved through exchange agreements, in which scientists may be ex- changed from one agency to another for specific pe- Federal agencies have special obligations, as stewards of public monies, to get the most out of research dollars. 72 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES riods to provide needed expertise. As an example, the Wetlands Classification System developed by the FWS was prepared with full-time assistance of sci- entists from the Corps and the Soil Conservation Service, and the authors of the report defining the system (Cowardin and others, 1979) included repre- sentatives from the FWS, the USGS, and NOAA. Written agreements such as Memorandums of Agree- ment or Memorandums of Understanding also are used to facilitate cooperation between agencies that share mutual objectives. Reimbursable and shared funding may be used to leverage available research dollars and take advantage of specific expertise avail- able in some agencies and lacking in others. Formal coordination may be required by specific legislative or administrative decisions, such as the Clinton administration's decisions relating to imple- mentation of the Breaux Bill, which requires agen- cies to coordinate in assessing damages and imple- menting corrective mechanisms in south Louisiana's coastal wetlands. Mon S. Yee, Natural Resources Conservation Service; Doug Ryan, U.S. Forest Service; David Correll, Smithsonian Institute; Mary E. Kentula, EPA; David A. Seyler, USGS; Clive Jorgensen, Department of Energy; and Joel Wagner, National Park Service. References Cited Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Classification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service, Report FWS/OBS-79/31, 131 p. Prayer, WE., Monahan, T.J., Bowden, D.C., and Graybill, F.A., 1983, Status and trends of wetlands and deepwater habitats in the conterminous United States, 1950's to 1970's: Fort Collins, Colorado State University, p. 32. U.S. Army Engineer Waterways Experiment Station, 1992, National summary of ongoing wetlands research by Federal agencies: Vicksburg, Miss., Prepared by the Wetlands Research Program, 69 p. ACKNOWLEDGMENTS Representatives of Federal agencies listed herein contributed to this report. The authors are particularly grateful to the following: Robert E. Stewart, Jr., NBS; FOR ADDITIONAL INFORMATION: Wetlands Research Program (CEWES-EP-W), U.S. Army Engineer Water- ways Experiment Station, 3909 Hall Ferry Rd., Vicksburg, MS 39180 U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources: MANAGEMENT AMD RESEARCH 73 Wetland Management and Research Wetland Mapping and Inventory By Bill 0. Wilen 1, Virginia Carter2 , and J. Ronald Jones; Wetland maps are a prerequisite for wetland in- ventory and for wetland development planning, man- agement, protection, and restoration. Maps provide information on wetland type, location, and size. De- tailed wetland maps are necessary for analysis of the effect of projects at specific sites and for providing baseline spatial data for the assessment of the effects of national policies and activities. Wetland maps are used by local, State, and Federal agencies, as well as by private industry and organizations. They are used for many purposes, including the development of comprehensive resource management plans, environ- mental impact assessments, natural resource inven- tories, habitat surveys, and the analysis of trends in wetland status. Several Federal agencies map wetlands in sup- port of their Congressional mandate. These include the U.S. Department of the Interior, U.S. Fish and Wildlife Service (FWS); the U.S. Department of Ag- riculture, Natural Resources Conservation Service (NRCS); and the U.S. Department of Commerce, National Oceanic and Atmospheric Administration (NOAA). The FWS has the primary responsibility for mapping and inventory of all the wetlands of the United States. The wetland maps produced by other agencies serve different purposes and generally in- volve cooperation with the FWS. THE U.S. FISH AND WILDLIFE SERVICE'S MAPPING AND INVENTORY ACTIVITIES The FWS National Wetlands Inventory is respon- sible for the mapping and inventory of wetlands throughout the United States. The Emergency Wet- lands Resources Act of 1986 and amendments to it in 1988 and 1992 define the responsibilities of the National Wetlands Inventory. (See the article "Wetland Protection Legislation" in this volume for more infor- mation on this and other wetland legislation.) History and Status of the National Wetlands Inventory In 1906, and again in 1922, the U.S. Department of Agriculture inventoried the wetlands of the United States to identify those that could be drained and con- verted to other uses (Wilen and Tiner, 1993). In 1954, the first nationwide wetland survey by the FWS cov- ered about 40 percent of the conterminous United States and focused on important waterfowl wetlands. This survey was not comprehensive by today's stan- dards, but it stimulated public interest in the conser- vation of waterfowl wetlands (Shaw and Fredine, 1956). (See the article "Wetlands as Bird Habitat" in this volume.) After the earlier inventories, and in response to passage of the Emergency Wetlands Resources Act and its amendments, the FWS established the Na- tional Wetlands Inventory. The program is designed to (1) produce detailed maps on the characteristics and extent of the Nation's wetlands, (2) construct a national wetlands data base, (3) disseminate wetland maps and digital data, (4) report results of State wet- land inventories, (5) report to Congress every 10 years on the status and trends of the Nation's wetlands, and (6) assemble and distribute related maps, digital data, and reports. The National Wetlands Inventory has produced more than 50,800 maps covering 88 percent of the conterminous United States, 30 percent of Alaska, and all of Hawaii and the U.S. Territories (fig. 44) Priorities for mapping have been based on the needs of the FWS. other Federal agencies, and State agen- Wetland maps are a prerequisite for wetland inventory, planning, management, protection, and restoration. EXPLANATION National Wetland Inventory map availability Final maps ^B Draft maps I I Unavailable Figure 44. Areas of the United States that have been mapped by the National Wetlands Inventory program and status of those maps, 1996. (Source: Data from U.S. Fish and Wildlife Service, National Wetlands Inventory files.) U.S. Fish and Wildlife Service. U.S. Geological Survey. 74 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES To date, almost 18,800 maps, representing 29 percent of the United States, have been digitized. cies. To date, mapping has been concentrated on the coastal zone (including the Great Lakes), prairie wetlands, playa lakes, flood plains of major rivers, and areas that reflect goals of the North American Waterfowl Management Plan (U.S. Fish and Wildlife Service, 1976). As a practical matter, priorities have been based on the availability of funding and the availability of high-quality aerial photographs. The National Wetlands Inventory produced maps at a rate of about 5 percent of the conterminous United States and about 2 percent of Alaska annually through 1995 about 3,200 1:24,000-scale maps in the con- terminous United States and about 60 1:63,360-scale maps in Alaska. The National Wetlands Inventory has published a series of documents on the trends in wetland losses and gains. The first of these reports was "Status and Trends of Wetlands and Deepwater Habitats in the Conterminous United States, 1950's to 1970's" (Prayer and others, 1983). In the Emergency Wetlands Resources Act of 1986 and subsequent amendments, Congress directed the National Wetlands Inventory to (1) update and improve the information contained in this report by 1990 and at 10-year intervals there- after and (2) estimate the number of acres of wetland habitat in each State in the 1780's and the 1980's and calculate the percentage of loss in each State. In re- sponse to this directive, the National Wetlands Inven- tory published a 1990 report to Congress titled "Wet- lands Losses in the United States, 1780's to 1980's" (Dahl, 1990). The National Wetlands Inventory also is prepar- ing a geographically referenced digital data base for wetlands so that wetland information can be placed in geographic information systems (CIS) for use with computers. These digital maps and information are easily transmitted over the Internet. To date, almost 18,800 maps, representing 29 percent of the United States, have been digitized (fig. 45). Statewide data bases have been digitized for Delaware, Hawaii, In- diana, Maryland, Illinois, New Jersey, Washington, Iowa, Minnesota, and West Virginia. Digitization is in progress for Florida, North Carolina, South Caro- lina, South Dakota, and Virginia. Wetland digital data are available for parts of 35 other States. In addition to wetland maps and status and trend reports, the National Wetlands Inventory produces special items related to the identification, mapping, and inventory of wetlands. The "National List of Plant Species that Occur in Wetlands" (Reed, 1988) is an important tool for identifying wetlands on the basis of their vegetation. A computerized data base for wet- land plants, developed by the National Wetlands In- ventory, also lists plants found in wetlands and ranks their affinity to the wetland environment. This infor- mation is important for determining whether an area is really a wetland. Additionally, the National Wet- lands Inventory has contributed to a list of hydric soils (soils found in wetlands) (U.S. Soil Conservation Service, 1991). Many published State wetland reports, including "Wetlands of Maryland" (Tiner and Burke, 1995), "Wetlands of Connecticut" (Metzler and Tiner, 1992), and "Status of Alaska Wetlands" (Hall, Prayer, and Wilen, 1994), contain wetland inventory results and other important information. Finally, in coopera- tion with the U.S. Geological Survey (USGS), the Na- tional Wetlands Inventory has published a map (scale of 1 inch equals 50 miles) showing the locations of major wetland complexes in the conterminous United States, Hawaii, and Puerto Rico (Dahl, 1991) and a map (scale of 1 inch equals 40 miles) of Alaska's wetland resources (Hall, 1991). OTHER FEDERAL AGENCIES' MAPPING AND INVENTORY ACTIVITIES Natural Resources Conservation Service. The NRCS (formerly the Soil Conservation Service) con- ducts its wetland inventory under the auspices of the wetland conservation provision (nicknamed "Swampbuster") of the Food Security Act of 1985. This Act provides for the reduction of a farmer's pro- gram benefits if wetlands are converted to agricultural production. In order to implement this act, the map- ping of the NRCS is focused on freshwater wetlands that have a high potential for agricultural conversion, such as those adjacent to or lying within the bound- aries of existing agricultural fields. The NRCS does not produce a standard map product. Many delineations are made on l:660-scale Figure 45. Areas of the conterminous United States and Hawaii where wetland data have been digitized by the National Wetlands Inventory program, 1996. (Source: Data from U.S. Fish and Wildlife Service, National Wetlands Inventory files.) t EXPLANATION National Wetland Inventory map 1 digitization Hi Completed ( U Not completed National Water Summary Wetland Resources: MANAGEMENT AND RESEARCH 75 The "Swampbuster" discourages the conversion of wetlands to cropland. This wetland, which was converted to cropland at one time, has been restored. (Photograph courtesy of the U.S. Fish and Wildlife Service.) The National Oceanic and Atmospheric Administration delineates coastal wetland and upland habitats, such as this coastal wetland at Chincoteague National Wildlife Refuge on Assateague Island, Va. (Photograph by Judy D. Fretwell, U.S. Geological Survey.) black-and-white aerial photographs; others are made on soil-survey base maps at scales that range from 1:10,000to 1:64,000 (Teels, 1990). Information sources for this program include recent and histori- cal aerial photographs, such as those regularly acquired by the U.S. Department of Agriculture, National Wetlands Inventory maps from the FWS, U.S. Department of Agriculture crop history records, and field verifications. National Oceanic and Atmospheric Administra- tion. 1\\t NOAA has developed the Coastal Wet- land Habitat Change Program in order to delineate coastal wetland habitats and adjacent uplands and plains to monitor changes in these habitats on a cycle of 1 to 5 years. The basis for monitoring will be a data base describing the areal extent and distribution of coastal wetlands in the conterminous United States. The program will help to determine the link- ages between estuarine and marine wetlands, as well as the distribution, abundance, and health of living marine resources. U.S. Geological Survey. The USGS compiles, produces, and disseminates topographic, hydrologic, and geologic maps and digital data related to wet- lands. The standard USGS l:24,000-scale topo- graphic map commonly is used as a base for wetland mapping by other Federal, State, and local agencies. However, because USGS maps depict wetlands as un- bounded symbols (fig. 46), the maps cannot be used to establish exact boundaries for wetlands. Interme- diate-scale (1:100,000) and large-scale maps (scales of 1:24,000 or greater) are used for project planning. Large-scale maps known as orthophoto quadrangles, which are made by manipulation of aerial photo- graphs to achieve a positionally accurate photo- graphic base map, are used as a base for State wet- land mapping. COORDINATION OF FEDERAL WETLAND MAPPING EFFORTS Differing needs of various Federal agencies can require different types of maps or different map scales. However, many needs can be satisfied by com- mon products, and efforts are being made to standard- ize maps and map products whenever possible or practical. Federal digital wetland mapping is coordi- nated by the Wetlands Subcommittee of the Federal Geographic Data Coordination group in an effort to meet requirements established by the Office of Man- agement and Budget. The Office of Management and Budget requires agencies to develop a national digi- tal spatial information resource in collaboration with State and local governments and the private sector. This requirement is for the purposes of (1) promot- ing the development, maintenance, and management of a national digital wetland data base; (2) encour- aging the development and implementation of stan- dards, exchange formats, specifications, procedures, and guidelines; (3) promoting interaction among other Federal, State, and local government agencies that have interests in the generation, collection, use, and transfer of wetland spatial data; (4) maintaining and disseminating information on the type and avail- ability of wetland spatial data; and (5) promoting the concept of effective wetland management. Efforts are made to standardize maps and map products when- ever possible or practical. 34 Figure 46. Unbounded symbols on a U.S. Geological Survey topographic map show the general location of wetlands. EXPLANATION Orchard Woods £L; Intermittent pond -^ Marsh or swamp J^ Wooded marsh or swamp 76 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES The National Wetlands Inventory uses the best and most appropriate aerial photographs available for mapping wetlands. PRODUCING NATIONAL WETLANDS INVENTORY MAPS Most natural-resource inventories make use of aerial photographs or satellite images combined with field verification. The National Wetlands Inventory uses the best and most appropriate aerial photographs available for mapping wetlands. The principal data source in the early 1980's was the l:80,000-scale, high-altitude, black-and-white aerial photography ac- quired by the USGS for topographic mapping and production of orthophoto quadrangles. After the USGS began its National High-Altitude Photography Program, 1:58,000-scale color-infrared photographs for the entire country became available; the National Wetlands Inventory uses these photographs exten- sively. In 1987, the USGS replaced the National High- Altitude Photography Program with the National Aerial Photography Program, which produces 1:40,000-scale color-infrared photographs; the Na- tional Wetlands Inventory uses these photographs as well. In some cases, the National Wetlands Inventory uses supplementary photography, such as some 1:60,000-scale color-infrared photographs of the prai- rie pothole region of the northern Great Plains, which were acquired from the National Aeronautics and Space Administration. Stereoscopic color-infrared photographs are best for identifying and delineating wetlands. Color, tex- ture, and pattern are important features of wetland vegetation and background soils. A combination of vegetation factors produce a specific response or sig- nature on the photograph (Wilen and Pywell, 1992). These vegetation factors include leaf size, shape, Figure 47. Wetland features such as water, vegetation, and soil are identified on an aerial photograph by their signatures (left), and these signatures are used to produce wetland maps (right). ('Source: U.S. Geological Survey, 1995 (left); T.E. Dahi, U.S. Fish and Wildlfie Service, unpub. data, 1992 (right).) structure, and arrangement; branching pattern; height; growth habit; and color. Determining the boundary of a wetland is the most difficult part of mapping. Normally, transitions are found at the boundary from upland vegetation to wetland vegetation, from nonhydric to hydric (wetland) soils, and from land that is not flooded to areas that are subject to flood- ing or saturation. On color-infrared photographs, water generally shows as a distinctive black and blue- black color because of its lack of reflectance. Wet- lands that have canopy openings and contain stand- ing water exhibit this signature along with assorted well and-vegetation signatures. Saturated soils show darker tones because of the nonreflectance of the soil- water component. Even when wetland basins are dry, the silt, clay, and other fine-grained materials hold more water than the upland soils hold, which results in a distinctive dark color because of the lack of in- frared reflectance. Vegetation characteristics help to identify wet- lands. Wetland vegetation generally is more dense, more crowded, and more concentrated than upland vegetation. Wetland vegetation normally exhibits a higher degree of lushness, vigor, and intensity than does upland vegetation. Even wheat grown in a dry wetland basin has a distinctive signature; it is more vigorous because of extra moisture in the basin. Dead and dying vegetation in flooded wetland basins also has distinctive signatures. When physiographic po- sitions are associated with the vegetative character- istics described above, wetland locations become more obvious on an aerial photograph (fig. 47). Patterns, or the repetition of the spatial arrange- ment, of vegetative types also provide important clues in the identification of wetlands. Basins that have a semipermanently flooded center may have a season- ally flooded band around the center and a temporarily flooded outer band. Patterns are not restricted to veg- etation they can include drainage patterns and land- use patterns. Unplanted basins in farm fields might indicate wetlands; land-cover patterns such as ridges and swales help separate uplands and wetlands. When wetlands are being mapped, the photointerpreter closely checks areas indicated by swamp symbols as wetlands on USGS topographic maps and NRCS soil survey maps to ensure their possible inclusion as wet- lands; such areas are considered wetlands unless strong evidence indicates otherwise. A typical National Wetlands Inventory map con- sists of wetland boundaries added to a black-and- white version of a 1:24,000-scale USGS topographic base map. Wetlands are classified according to guide- lines developed by Cowardin and others (1979). (See article "Wetland Definitions and Classifications in the United States" in this volume.) These wetland clas- sifications are shown on the map as alpha-numeric codes that are identified in a map explanation at the bottom of the map. Many steps are involved in the production of a wetland map from selecting the sites for field verification to delineation, quality control, and production of the final map product (fig. 48). All National Wetlands Inventory photointerpreters are trained extensively in wetland identification, the FWS wetland classification system, and the field identifi- cation of wetland plants and soils in order to ensure the best quality, most accurate maps. National Water Summary Wetland Resources: MANAGEMENT AND RESEARCH 77 STEPS IN PRODUCING NATIONAL WETLANDS INVENTORY MAPS 1. Determine project area. 2. Obtain source materials. 3. Prepare source materials {photo A}. 4. Review photo interpretation and plan field trip (photo B). 5. Conduct a field reconnaissance of study area. 6. Make photo interpretation (photo O. 7. Check photointerpretation (quality control) (photo D). 8. Transfer photointerpreted data to base map (photo E). 9. Check transferred information (quality control). 10. Prepare copy of draft map for review. 11. Conduct review of draft maps. 12. Make changes to draft map manuscript (photo f). 13. Conduct final quality- control checks. 14. Produce final map for distribution (photo G). 15. Digitize the final map (photo H). Figure 48. The sequence of steps in producing National Wetlands Inventory maps. (Photographs A and E by Judy D. Fretwell, U.S. Ceological Survey; all other photographs by Donald W. Woodard, U.S. Fish and Wildlife Service.) 78 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES HOW AND WHERE TO GET NATIONAL WETLANDS INVENTORY MAPS Maps of the National Wetlands Inventory can be acquired from 33 State-run distribution centers, 6 USGS Earth Science Information Center regional offices, or by calling the USGS national toll-free number: 1-800-USA-MAPS. Maps can also be viewed at the Library of Congress and the Federal Depository Library System and downloaded cost-free through the National Wetlands Inventory Home Page on the Internet at http://www.nwi.fws.gov. The six re- gional USGS Earth Science Information Centers pro- vide online computer links to the National Wetlands Inventory map data base, which contains current in- formation about the availability and production his- tory of National Wetlands Inventory maps and digi- tal data. Digital data are available in Digital Line Graph 3 (DLG3) optional or Geographic Resources Analysis Support System (GRASS) formats; latitude and longitude, State Plane Coordinates, or Universal Transverse Mercator (UTM) coordinate systems; and 9-track, 8-mm, or 1/4-inch cassettes in UNIX-TAR or ASCII tape formats. Other products available at cost include acreage statistics by quadrangle, county, or study area and color-coded wetland maps. References Cited Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Classification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service, Biological Services Program Report FWS/ OBS-79/31, 131 p. Dahl, T.E., 1990, Wetlands-Losses in the United States, 1780's to 1980's: Washington, D.C., U.S. Fish and Wildlife Service, Report to Congress, 21 p. ____1991, Wetland resources of the United States: U.S. Fish and Wildlife Service National Wetlands Inventory map, scale 1:3,168,000. Prayer, WE., Monahan, T.J., Bowden, D.C., and Graybill, F.A., 1983, Status and trends of wetlands and deepwater habitats in the conterminous United States, 1950's to 1970's: Fort Collins, Colo., Colorado State University, 32 p. Hall, J.V., 1991, Wetland resources of Alaska: U.S. Fish and Wildlife Service National Wetlands Inventory map, scale 1:2,500,000. Hall, J.V., Prayer, WE., and Wilen, B.O., 1994, Status of Alaska wetlands: Anchorage, Alaska, U.S. Fish and Wildlife Service, 33 p. Metzler, K.J., andTiner, R.W, 1992, Wetlands of Connecti- cut: State Geological and Natural History Survey of Connecticut in cooperation with the U.S. Fish and Wildlife Service National Wetlands Inventory, Report of Investigations no. 13, 115 p. Reed, P.B., Jr., 1988, National list of plant species that oc- cur in wetlands 1988 national summary: U.S. Fish and Wildlife Service Biological Report 88 (24), 244 p. Shaw, S.P., andFredine, C.G., 1956, Wetlands of the United States Their extent and their value to waterfowl and other wildlife: U.S. Fish and Wildlife Service Circu- lar 39, 67 p. Teels, B.M., 1990, Soil Conservation Service's wetland inventory, in Kiraly, S.J., Cross, FA., and Buffington, J.D., eds., Federal coastal wetland mapping programs; a report by the National Ocean Pollution Policy Board: Washington, D.C., U.S. Fish and Wildlife Service Bio- logical Report 90 (18), p. 93-103. Tiner, R.W, and Burke, D.G., 1995, Wetlands of Maryland: Annapolis, Md., Maryland Department of Natural Re- sources, Water Resource Administration, in coopera- tion with U.S. Fish and Wildlife Service, National Wetlands Inventory, 193 p. U.S. Fish and Wildlife Service, 1976, Existing state and local wetland surveys (1965-1975), v. II, Narrative: Washington, D.C., U.S. Fish and Wildlife Service, Office of Biological Services Report, 453 p. U.S. Geological Survey, 1995, South Florida Satellite Im- age Map, 1993: Reston, Va., U.S. Geological Survey, 1 sheet, scale 1:500,000. U.S. Soil Conservation Service, 1991, Hydric soils of the United States: U.S. Soil Conservation Service in co- operation with the National Technical Committee for Hydric Soils, Miscellaneous Publication No. 1491, 3d ed., unnumbered pages. Wilen, B.O., and Pywell, H.R., 1992, Remote sensing of the Nation's wetlands, National Wetlands Inventory, in Proceedings: Forest Service Remote Sensing Applica- tions Conference, 4th biennial, Orlando, Fla., unnum- bered pages. Wilen, B.O., and Tiner, R.W, 1993, Wetlands of the United States, in Whignam, D.F., Dykyjova, Dagmar, and Hejny, Slavomil, eds., Wetlands of the world I Inven- tory, ecology, and management: Dordrecht, The Neth- erlands, Kluwer Academic Publishers, p. 515-636. FOR ADDITIONAL INFORMATION: Bill O. Wilen, U.S. Fish and Wildlife Service, National Wetlands Inventory, 4401 N. Fairfax Drive, Room 400 Arlington, VA 22203; Virginia Carter, U.S. Geological Survey, 430 National Cen- ter, Reston, VA 22092 U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources: MANAGEMENT AND RESEARCH 79 Wetland Management and Research Wetland Functions, Values, and Assessment By Richard P. Novitzki 1 , R. Daniel Smith,2 and Judy D. Fretwell3 Wetlands, or the lack thereof, were a significant factor in the severe flooding in the Upper Mississippi and Missouri River Basins in the summer of 1993 (Parrett and others, 1993) (fig. 49). Damages asso- ciated with the flooding were undoubtedly worse than they would have been if flood-plain wetlands had still been in place. Human modification of the original wetlands (a common practice in the early part of this century) had destroyed the ability of the wetlands to modify flooding. (See the article "Effects of the Great Midwest Flood of 1993 on Wetlands" in this volume.) Flood control, however, is only one of the values that wetlands have for society. In order to protect wet- lands, the public first must recognize the values of wetlands. People need to understand what is lost when a wetland is changed into an agricultural field, a parking lot, a dump, or a housing development. Un- derstanding the functions of wetlands will make it easier to evaluate wetlands when other uses are con- sidered. RECOGNITION OF WETLAND FUNCTIONS AND THEIR VALUES In the 1970's, scientists, ecologists, and conser- vationists began to articulate the values of wetlands. At a wetland conference in 1973, wetlands were ac- knowledged to be an important part of the hydrologic cycle (Helfgott and others, 1973). In 1977, participa- tion at the first National Wetland Protection Sympo- sium attended by more than 700 people demon- strated a growing interest in the value of wetlands and the need to protect them (Kusler and Montanari, 1978). At a Wetland Values and Management Confer- ence in 1981, scientists defined the unique qualities of wetlands and developed a list of wetland functions (Richardson, 1981). In addition to the more com- monly recognized habitat functions of wetlands, the scientists described hydrologic and water-quality functions. During the 1980's, participants at many more conferences and symposia expanded the under- standing and appreciation of the values of wetlands (Kusler and Riexinger, 1986). WETLAND FUNCTIONS DEFINED Wetland functions are defined as a process or series of processes that take place within a wetland. These include the storage of water, transformation of nutrients, growth of living matter, and diversity of wetland plants, and they have value for the wetland itself, for surrounding ecosystems, and for people. Functions can be grouped broadly as habitat, hydro- logic, or water quality, although these distinctions are somewhat arbitrary and simplistic. For example, the value of a wetland for recreation (hunting, fishing, bird watching) is a product of all the processes that work together to create and maintain the wetland. Not all wetlands perform all functions nor do they perform all functions equally well. The location and size of a wetland may determine what functions it will perform. For example, the geographic location may determine its habitat functions, and the location of a wetland within a watershed may determine its hydro- logic or water-quality functions (fig. 50). Many fac- tors determine how well a wetland will perform these functions: climatic conditions, quantity and quality of water entering the wetland, and disturbances or al- Not all wetlands perform all functions nor do they perform all functions equally well. Wetlands are among the most productive habitats in the world. Figure 49. Flooding in the Upper Mississippi River Basin, summer 1993. (Photograph ©Cameron Davidson, 1993.) 1 ManTech Environmental Technology, Inc. 2 U.S. Army Corps of Engineers. 3 U.S. Geological Survey. 80 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES ISOLATED WETLANDS ' I . !, '! LAKE MARGIN WETLANDS RIVERINE WETLANDS STUARINE AND COASTAL WETLA BARRIER ISLAND WETLANDS CHARACTERISTICS AND FUNCTIONS OF WETLANDS Isolated Wetlands 1. Waterfowl feeding and nesting habitat 2. Habitat for both upland and wetland species of wildlife 3. Floodwater retention area 4. Sediment and nutrient retention area 5. Area of special scenic beauty Lake Margin Wetlands 1. See "isolated wetlands" above 2. Removal of sediment and nutrients from inflowing waters 3. Fish spawning area Riverine Wetlands 1. See "isolated wetlands" above 2. Sediment control, stabilization of river banks 3. Flood conveyance area Estuarine and Coastal Wetlands 1. See "isolated wetlands" above 2. Fish and shellfish habitat and spawning areas 3. Nutrient source for marine fisheries 4. Protection from erosion and storm surges Barrier Island Wetlands 1. Habitat for dune-associated plant and animal species 2. Protection of backlyjng lands from high-energy waves 3. Scenic beauty Figure 50. Wetland functions depend upon the location of the wetland within a watershed. (Source: Modified fromJ.A. Kusler, Our National Heritage: A Protection Guidebook. Copyright (c) 1983 by the Environmental Law Institute. Reprinted by permission.) Timber harvest in a bottom-land forested wetland. (Photograph by R. Daniel Smith, U.S. Army Engineer Waterways Experiment Station.) Hay harvest in a prairie wetland. (Photograph by Richard P. Novitzki, ManTech Environmental Technology, Inc.) National Water Summary Wetland Resources: MANAGEMENT AND RESEARCH 81 teration within the wetland or the surrounding eco- system. Wetland disturbances may be the result of natural conditions, such as an extended drought, or human activities, such as land clearing, dredging, or the introduction of nonnative species. Perhaps wetlands are best known for their habi- tat functions, which are the functions that benefit wildlife. Habitat is defined as the part of the physical environment in which plants and animals live (Lapedes, 1976), and wetlands are among the most productive habitats in the world (Tiner, 1989). They provide food, water, and shelter for fish, shellfish, birds, and mammals, and they serve as a breeding ground and nursery for numerous species. Many en- dangered plant and animal species are dependent on wetland habitats for their survival. (See the article "Wetlands as Bird Habitat" in this volume.) Hydro- logic functions are those related to the quantity of water that enters, is stored in, or leaves a wetland. These functions include such factors as the reduction of flow velocity, the role of wetlands as ground-wa- ter recharge or discharge areas, and the influence of wetlands on atmospheric processes. Water-quality functions include the trapping of sediment, pollution control, and the biochemical processes that take place as water enters, is stored in, or leaves a wetland. (See article "Wetland Hydrology, Water Quality, and As- sociated Functions" in this volume for more informa- tion on hydrologic and water-quality functions.) WETLAND VALUES DEFINED If something has "value," then it is worthwhile, beneficial, or desirable. The value of a wetland lies in the benefits that it provides to the environment or to people, something that is not easily measured. Wetlands can have ecological, social, or economic values. Wetland products that have an economic value, such as commercial fish or timber, can be assigned a monetary value. True wetland value, however, goes beyond money. How much value does one place on the beauty of a wetland or its archeological signifi- cance? Wetland values are not absolute. What is valu- able and important to one person may not be valu- able to another person. As an example, the value of a wetland as duck habitat may be important to the hunter or birdwatcher but not to the farmer who owns the land. "While wetland functions are natural processes of wetlands that continue regardless of their perceived value to humans, the value people place on those func- tions in many cases is the primary factor determin- ing whether a wetland remains intact or is converted for some other use" (National Audubon Society, 1993). In addition, values assigned to wetland func- tions may change over time as society's perceptions and priorities change. The values that benefit society as a whole tend to change slowly; however, the val- ues assigned by individuals or small groups are arbi- trary, and most are subject to rapid and frequent change and may even conflict. For example, timber production may be improved by draining a wetland site, whereas waterfowl production may be improved by impounding more water. Society may have to re- solve conflicts regarding the management or preser- vation of wetlands and their functions. Furthermore, Velocity Reduction Atmospheric Processes ^ Ground-water/Surff ace-water & Interaction ^ /- society may have to choose among wetland functions that benefit individuals or small groups, that are of value to most of society, or that are important to the maintenance of the wetland itself. Wetland functions have value on several levels internal, local, regional, and global. All wetland func- tions are internal, but the values or benefits of wet- land functions can be internal or external to the wet- land (fig. 51). Functions that provide internal values are the functions that maintain or sustain the wetland and are essential to the continued existence of the wet- land. Conversely, many functions have external val- ues that extend beyond the wetland itself. On a local scale, wetlands affect adjacent or nearby ecosystems, for example, by reducing flooding in downstream communities or by removing nutrients from waste- water. However, the broadest influence of wetland functions is global. Wetlands are now thought to have a significant effect on air quality, which is influenced by the nitrogen, sulfur, methane, and carbon cycles. In addition, migrating birds are dependent upon wet- lands as they travel. PURPOSE OF WETLAND ASSESSMENT Many times when decisions are made about de- velopment of an area, such as the selection of a site for a large commercial or industrial facility, the choice of sites is not between a wetland or an upland, but be- tween wetlands. In areas that have many wetlands, all alternative sites or routes for roads for a major facil- ity may involve the destruction or alteration of wet- lands. In such cases, legal requirements commonly exist that require the replacement of destroyed wet- lands. Even when a choice must be made between a wetland site and an upland site, the upland site may have great value to the community. Managers, plan- ners, regulators, and even the general public have long J Figure 51. Wetland functions and internal and external values. A system of wetland assessment is necessary to ensure that the most valuable wetlands are protected. 82 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES The WET evaluates functions and values in terms of effectiveness, opportunity, social significance, and habitat suitability. felt the need to have in place a system of assess- ment or evaluation that would make the choices clearer and ensure that the most valuable wetlands are pre- served. Such an evaluation system could be based entirely or partly on wetland function if values could be assigned to individual functions. Wetland assessment methods have been or are be- ing developed that assign numerical values to wetland functions. Some methods assign values on the basis of the benefits to the wetland itself by considering the question: How important is this function in terms of maintaining this particular wetland? Other methods assign values on the basis of the benefits to surround- ing ecosystems or to humans. The types of questions considered in this approach are as follows: How important is this function to environmental quality downstream? How does this function benefit soci- ety? This latter assessment method allows for the comparison of the worth of one wetland to that of another wetland. The development of a single method for assess- ing the functions of wetlands or for assigning values to the functions of wetlands is not a simple task. In- deed, probably no one method will satisfy all needs. However, assessing each function of a wetland and then assigning a value to each function is a step to- ward the protection of sensitive wetlands. Further- more, an evaluation system that provides the basis for comparing wetlands would facilitate mitigation for unavoidable wetland losses, would provide a tool for determining the success (or failure) of programs and policies intended to protect or manage wetland re- sources, and would assist in identifying long-term trends in the condition of wetland resources. WETLAND ASSESSMENT METHODS The three wetland assessment methods described herein are representative of the methods that are avail- able or are being used by wetland managers and plan- ners. The Wetland Evaluation Technique was devel- oped for the Federal Highway Administration and has been used widely. It assigns values to specific func- tions of individual wetlands. The Environmental Monitoring Assessment Program Wetlands was developed by the Environmental Protection Agency. It is presented here as an example of a program that focuses on determining the ecological condition of a population of wetlands in a region. It does this by comparing the function of a statistical sample of wet- lands to reference wetlands in the region. The Hydrogeomorphic approach is being developed by the U.S. Army Corps of Engineers for assessing wetland functions. It combines features of the other two meth- ods by measuring the functions of individual wetlands and also by comparing them to functions performed by other wetlands. Wetland Evaluation Technique (WET) The WET is a comprehensive approach for evalu- ating individual wetlands that was developed in 1983 (Adamus, 1983; Adamus and Stockwell, 1983) and revised in 1987 under the auspices of the U.S. Army Corps of Engineers (Adamus and others, 1987). The WET considers wetland functions to be the physical, chemical, and biological characteristics of a wetland. It assigns wetland values to the characteristics that are valuable to society. The following functions are as- signed values by WET: Ground-water recharge Ground-water discharge Floodflow alteration Sediment stabilization Sediment/toxicant retention Nutrient removal/transformation Production export Wildlife diversity/abundance Aquatic diversity/abundance Recreation Uniqueness/heritage The recreational pleasures of a wetland are captured in this photo at Horicon Marsh, Wis. (Photograph byPhillip I, Redman, U.S. Geological Survey.) National Water Summary Wetland Resources: MANAGEMENT AND RESEARCH 83 The WET evaluates functions and values in terms of effectiveness, opportunity, social significance, and habitat suitability. Effectiveness assesses the capabil- ity of a wetland to perform a particular function. For example, a wetland that has no outlet is assigned a high value for sediment retention, whereas a wetland just downstream from a dam is assigned a low value. Opportunity assesses the potential for a wetland to perform a specific function; for example, a wetland in a forested area that has no potential sediment sources would be assigned a low opportunity value for sediment retention. Social significance assesses the value of a wetland in terms of special designations (does it have endangered species?), potential eco- nomic value (is it used regularly for recreational ac- tivities?), and strategic location (is it in a State where very few wetlands of its type remain?). The WET uses "predictors" that relate to the physical, chemical, and biological characteristics of the function being evalu- ated. As an example, the presence or absence of a con- stricted outlet from a wetland could be used to pre- dict whether the wetland might be effective in stor- ing floodwaters. In addition, WET can be used to assess the habitat suitability for waterfowl and wet- land-dependent birds, fish, and invertebrates. The WET approach was designed to provide a balance between costly, site-specific studies and the "best professional judgment" approach, which is less costly but lacks reproducibility. The WET method is intended to be used by any environmental profes- sional, so that an engineer can evaluate biological functions or a biologist can evaluate hydrologic func- tions. First, information resources are obtained for the wetland, the area surrounding the wetland, and the area downstream from the wetland. Then a series of questions is answered about the wetland's watershed, topography, vegetation, and other features. By pro- gressing next through a series of flow charts (or an available computer software package), an evaluation can assign a probability rating of "high," "moderate," or "low" to each of the functions listed above (except for recreation) and a habitat suitability rating for waterfowl, fish, and other wildlife (Adamus, 1988). The probability rating is an estimate of the "likeli- hood" that a wetland will perform a function on the basis of its characteristics. It does not estimate the de- gree or magnitude to which a function is performed. Recreation is not evaluated because no scientific ba- sis exists for making an objective assessment with- out extensive data collection at the site. The WET approach probably has been applied to nearly every type of wetland in every State; however, it has proved to be unwieldy to use. For most users, the need to be able to apply this method to every wetland in every part of the United States makes the system unnecessarily cumbersome. For example, most users are interested in a local area and prefer not to enter data repeatedly for local characteristics that are unlikely to change, as is required in the WET approach. In order to refine the method for specific regions and to refine the thresholds among the low, medium, and high values, Adamus (1988) intended that regional versions and five different levels of WET be developed, neither of which has happened. Despite its shortcomings, however, WET continues to be used by those who are familiar with it. Furthermore, much of the data generated by its application could be used to create data bases that would simplify its use and would improve its regional application. Environmental Monitoring Assessment Program Wetlands (EMAP Wetlands) In 1988, the Environmental Protection Agency initiated the Environmental Monitoring Assessment Program (EMAP) in order to provide improved in- formation on the status and trends in the condition of the Nation's ecological resources. The wetlands part of EMAP was intended to develop an approach for assessing the condition (how well a wetland is per- forming its functions) of different types of wetlands in a region and in the Nation as a whole (Novitzki, EMAP Wetlands identifies "indicators" of condition, standardizes methods of measurement, and establishes a national network. Sheep foraging at a wetland near Bridgeport, Calif. (Photograph by A.S. Van Denburgh, U.S. Geological Survey.) 84 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES The HCM approach represents a combination of the WET and EMAP Wetlands approaches 1994; Novitzki and others, 1994). The near-term ob- jectives of the program were to conduct research in order to identify "indicators" of wetland condition, to standardize methods of measurement, and to es- tablish a national network for monitoring wetlands at regional scales and over long periods (decades). In some places, it is impossible or impractical to mea- sure wetland functions directly; therefore, character- istics or "indicators" are measured, and these indi- cate how well certain functions are being performed by the wetland. For example, the number of water- fowl per acre can be calculated from actual field mea- surements and then can be used as an indicator of how well a wetland is performing its waterfowl habitat function. The EMAP Wetlands program was intended to have three phases. First, pilot studies were to be con- ducted to evaluate the ability of selected indicators to make a distinction between healthy and degraded wetlands. Next, regional demonstrations were to be conducted by using some of the best indicators from the pilot studies. These demonstrations would confirm the ability of the program to assess the condition of a specific type of wetland in a specific region. Finally, the program would be implemented to monitor the condition of a specific wetland type in a region. Only Phase I has been conducted. Data from pilot and demonstration studies in Phase I are being analyzed to develop preliminary indices of signs of the health of a wetland. One index will be for biological integrity, which combines in- dicators of healthy plant and animal communities. Biological characteristics of the sampled wetlands will be compared with those of the most unaltered wetlands of the same type in the region, known as ref- erence wetlands. This comparison is based on the as- sumption that the least altered wetlands have sustain- able biological integrity. Other likely indices will be related to the follow- ing: habitat integrity (how does the population of wa- terfowl, finfish, or shellfish in sampled wetlands com- pare with that in reference wetlands?), hydrologic integrity (how similar is the hydrologic regime in the sampled wetlands to that in reference wetlands?), and water-quality improvement (how do sediment trap- ping and other water-quality processes in sampled wetlands compare with those in reference wetlands?). Wetland health may be evaluated either by similarity (how similar are sampled wetlands to reference wet- lands?) or by biological criteria (are the sampled wetlands above or below a level determined from measurements obtained in the reference wetlands?). The comparison of the condition of sampled wetlands with the condition of reference wetlands provides a means for telling the difference between changes that result from long-term changes in climate (both sampled wetlands and reference wetlands will be af- fected) and changes that happen because of manage- ment actions, regulatory policy, or other human fac- tors that affect wetlands (only the sampled wetlands will be affected). Pilot studies of salt marshes in the Gulf of Mexico and prairie pothole wetlands of the Midwest have been completed. Results of these studies have been evalu- ated to identify the indicators that most effectively reveal the difference between healthy and degraded wetlands. In the salt marshes, the indicators that seem to hold the greatest promise (Turner and Swenson, 1994) are as follows: Ratio of vegetated areas to open water Number of plant species (or the diversity of plant species) Biomass (production of plant material per unit area) Amount of organic matter in soil Salinity Serene beauty is provided by this restored wetland in Montana. (Photograph by Edith B. Chase, U.S. Geological Survey.) National Water Summary-Wetland Resources: MANAGEMENT AND RESEARCH 85 In prairie pothole wetlands, indicators of the health of a wetland that seem to hold the greatest promise at the local level (L.M. Cowardin, U.S. Fish and Wildlife Service, oral commun., 1994) are: Amount of developed land in the surrounding up- land Rates of increase and decrease in the number of water-filled basins or in the area of water surface between April (spring thaw) and August (end of summer) Ratio of temporary to seasonal to semipermanent wetlands At the level of the individual wetland ecosystem, other promising indicators (L.M. Cowardin, oral commun., 1994) are: Diversity of plant species Number and types of species of large invertebrates Range of water-level fluctuation Sedimentation rate Hydrogeomorphic Approach (HGM) In 1990, the U.S. Army Corps of Engineers be- gan developing the Hydrogeomorphic Approach (HGM) as a way to provide a foundation for assess- ing the physical, chemical, and biological functions of wetlands (Brinson, 1993; Smith and others, 1995). The program, still being developed, is intended to revise and simplify the WET approach described above (Adamus and others, 1987), as well as make it more applicable to specific regions. The WET pro- cedure develops a profile of specific characteristics (predictors) for an individual wetland, and these are used to assess the degree of effectiveness of the dif- ferent functions of the wetland. The HGM approach compares the characteristics of a specific wetland with the characteristics of a group of wetlands (ref- erence wetlands) in the region, and this information is used to assess the degree to which the individual wetland is performing selected functions. Thus, the HGM approach represents a combination of the WET and EMAP Wetlands approaches. Wetland charac- teristics to be evaluated by HGM are limited to those that are important in the specific region and hydro- geomorphic setting. Hence, different characteristics will be identified and evaluated for different hydrogeomorphic settings, such as closed basins in the Midwest (for example, prairie pothole wetlands), river-edge wetlands in the Southeast (for example, bottom-land hardwood wetlands), and coastal wet- lands (for example, salt marshes). In the HGM approach, local wetland scientists or managers identify the functions that are performed by wetlands in a specific hydrogeomorphic setting in that region. Also, they identify wetland characteris- tics (indicators), such as plant communities, plant species, and density of stems, that suggest whether or not a wetland is performing a specific function, such as slowing the flow velocity of floodwater. Next, the value of each function is determined by measur- ing the degree to which that function is likely to be performed. This is based on the characteristics of the indicators. For example, if lines of debris are selected as an indicator that a wetland has been flooded, their altitude may be used to determine how deep the water may have been during flooding and thus how much water may be stored in the wetland. The nature of the debris lines also may suggest the velocity of the water as it moved through the wetland. For ex- ample, small leaves and twigs suggest slow-moving water, small branches suggest somewhat swifter water, and large branches and tree trunks suggest very high velocities. Sediment deposits observed at the site may suggest the depositional characteristics. For ex- ample, no sediment deposits suggest little deposition, thin silt deposits suggest that slow-moving water was sustained for long periods, and gravel and cobble de- posits might suggest that water was flowing rapidly when it entered the site but then slowed significantly at the site. A wetland assessment provided by the HGM ap- proach will likely be a "site profile" that lists the site characteristics that are related to identified wetland functions. This profile then will be compared with characteristics of the reference wetlands (all wetlands in the region in the same geomorphic class) in order to rank the site. A data base that contains profiles of wetland characteristics (indicators of wetland func- tions) for each wetland type (hydrogeomorphic class) will be established for each region. These data will define the range of characteristics found in these wet- lands. At present (1995), the HGM approach is in de- velopment and has not been released to the public. Field tests of this assessment method have been con- ducted in river-edge wetlands in the Pacific North- west, the Northeast, the Rocky Mountains, the South- west, and the Southeast; in coastal wetlands in the Pacific Northwest, the North and South Atlantic States, and the gulf coast States; and in closed-basin wetlands in the Midwest. Data and insights derived from these tests are being compiled and will be evalu- ated in regional workshops. Following those evalua- tions, manuals of draft HGM methods will be pre- pared and presented for comment and review in re- gional workshops. CONCLUSIONS If any hope remains for preserving the Nation's wetland resources, it depends upon obtaining public support. Public support can be won if scientists can explain clearly how wetlands function, how they in- teract with their surroundings, and how their func- tions can benefit society. Wetlands have come under intensive scientific study only during the last two decades. Techniques of wetland evaluation will im- prove as scientists gather more information about the processes that take place in wetlands and about the similarities and differences among the functions of different types of wetlands. In order to develop pub- lic support and to encourage enlightened policy de- cisions and regulations, it is critical to create and maintain a data base of wetland characteristics in which the data are reliable, comparable, and repeat- able at periodic intervals in order to monitor long- term trends. More than one approach to wetland evaluation is possible, as illustrated by the examples discussed above. Wetland functions and their values to humans and other living matter may be assessed for an indi- vidual wetland by using approaches such as WET or It is critical to create and maintain a data base of wetland characteristics in which the data are reliable, comparable, and repeatable. 86 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES HGM. After this, they can be compared with other natural wetlands in a region by using the HGM approach. Both WET and HGM can be used to determine the amount of mitigation required to off- set unavoidable wetland loss, as well as to evaluate the degree of success of individual mitigation projects. (See article "Wetland Protection Legisla- tion" in this volume for further discussion of mitiga- tion.) The EMAP Wetlands approach suggests that it might be possible to examine the condition (pris- tine or degraded) of a population of wetlands in a specified area. Periodic reevaluation of this popula- tion of wetlands might be used to determine trends in their condition and to identify the effects of broad policy decisions (such as "no net loss"), programs (such as mitigation banking where wetlands are cre- ated or restored to offset losses of other wetlands), or natural phenomena (such as climate change). References Cited Adamus, P.R, 1983, FHWA Assessment method, v. 2 of Method for wetland functional assessment: Washing- ton, D.C., U.S. Department of Transportation, Federal Highway Administration Report no. FHWA-IP-82-24, 134 p. ___1988, The FHWA/Adamus (WET) method for wet- land functional assessment., in Hook, D.D., McKee, W.H., Jr., Smith, H.K., Gregory, James, Burrell, V.G., Jr., DeVoe, M.R., Sojka, R.E., Gilbert, Stephen, Banks, Roger, Stolzy, L.H., Brooks, Chris, Mathews, T.D., and Shear, T.H., Management, use, and value of wetlands, v. 2 of The ecology and management of wetlands: Port- land, Oreg., Timber Press, p. 128-133. Adamus, P.R., Clairain, E.J., Jr., Smith, R.D., and Young, R.E., 1987, Wetland Evaluation Technique (WET), v. 2 o/Methodology: Vicksburg, Miss., U.S. Army Corps of Engineers, Waterways Experiment Station, Opera- tional Draft Technical Report, 206 p. + appendixes. Adamus, PR., and Stockwell, L.T., 1983, Critical review and evaluation concepts, v. 1 of Method for wetland functional assessment: Washington, D.C., U.S. Depart- ment of Transportation, Federal Highway Administra- tion Report no. FHWA-IP-82-23, 176 p. Brinson, M.M., 1993, Hydrogeomorphic classification for wetlands: Washington, D.C., U.S. Army Corps of En- gineers, Wetlands Research Program Technical Report WRP-DE-4, 79 p. Helfgott, T.B., Lefor, M.W., and Kennard, W.C., 1973, First Wetland Conference: Storrs, Conn., University of Con- necticut, Institute of Water Resources, Report 21, Pro- ceedings, 199 p. Kusler, J.A., 1983, Our national wetland heritage A pro- tection guidebook: Washington, D. C., Environmental Law Institute, p. 4. Kusler, J.A., and Montanari, J.H., 1978, National Wetland Protection Symposium: U.S. Fish and Wildlife Service, Office of Biological Services. FWS/OBS-78-97, Pro- ceedings, 255 p. Kusler, J.A., and Riexinger, Patricia, eds., 1986, National Wetland Assessment Symposium: Albany, N.Y., Asso- ciation of State Wetland Managers, Proceedings, 331 p. Lapedes, D.N., ed., 1976, McGraw-Hill dictionary of sci- entific and technical terms: New York, McGraw-Hill Book Company, 1634 p. National Audubon Society, 1993, Saving wetlands A citizen's guide for action in the Mid-Atlantic region: Camp Hill, Pa., National Audubon Society, 130 p. Novitzki, R.P., 1994, EMAP Wetlands A program for assessing wetland condition, in Mitsch, W.J., ed., Glo- bal wetlands Old World and New: New York, Elsevier Science Publishers, p. 691-709. Novitzki, R.P., Rosen, B.H., McAllister, L.S., Ernst, T.L., Huntley, B.E., and Dwire, K., 1994, EMAP Wet- lands Research strategy for the assessment of wetland condition: Corvallis, Oreg., U.S. Environmental Pro- tection Agency, Environmental Research Laboratory, 149 p. Parrett, Charles, Melcher, N.B., and James, R.W., Jr., 1993, Flood discharges in the upper Mississippi River basin, 1993: U.S. Geological Survey Circular 1120-A, 14 p. Richardson, Brandt, ed., 1981, Selected proceedings of the Midwest Conference on Wetland Values and Manage- ment: Navarre, Minn., Freshwater Society, 660 p. Smith, R.D., Ammann, Alan, Bartoldus, C., and Brinson, M.M., 1995, An approach for assessing wetland func- tions using hydrogeomorphic classification, reference wetlands, and functional indices: Vicksburg, Miss., U.S. Army Engineers Waterways Experiment Station, Technical Report TRWRP-DE 10, [100 p.] Tiner, R.W, 1989, Wetlands of Rhode Island: Newton Cor- ner, Mass., U.S. Fish and Wildlife Service, National Wetlands Inventory, 71 p., appendix. Turner, R.E., and Swenson, E.M., 1994, Indicator develop- ment for evaluating estuarine emergent conditions salt marsh pilot technical narrative (draft final re- port): Baton Rouge, La., Louisiana State University, v. 1,65 p. FOR ADDITIONAL INFORMATION: Richard P. Novitzki, ManTech Environmental Technology, Inc., 1600 S.W. West- ern Blvd., Corvallis, OR 97333; R. Daniel Smith, U.S. Army Engineer Waterways Experiment Station, 3909 Halls Ferry Road, Vicksburg, MS 39180; Judy D. Fretwell, U.S. Geo- logical Survey, 407 National Center, Reston, VA 22092 U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources: RESTORATION, CREATION, AND RECOVERY 87 Restoration, Creation, and Recovery of Wetlands Wetland Restoration and Creation Mary E. Kentula1 The benefits of restoration of degraded or de- stroyed wetlands and creation of new wetlands has only recently been recognized. As the population has ex- panded across the Nation during the past few centu- ries, wetlands have been drained and altered to accom- modate human needs. These changes to wetlands have directly, or indirectly, brought about changes in the migratory patterns of birds, local climate, and the makeup of plant and animal populations. In the past, people used wetland plants and animals for shelter and food. More recently, people have become more aware of other benefits that wetlands provide water-qual- ity improvement, flood attenuation, esthetics, and rec- reational opportunities. Now, it is recognized that nu- merous losses are incurred when a wetland is damaged or destroyed. Restoration and creation can help main- tain the benefits of wetlands and their surrounding eco- systems, and at the same time accommodate the hu- man need for development. Wetland restoration rehabilitates a degraded wet- land or reestablishes a wetland that has been destroyed. Restoration takes place on land that has been, or still is, a wetland. A term commonly associated with res- toration is "enhanced." An enhanced wetland is an existing wetland that has been altered to improve a particular function, usually at the expense of other functions. For example, enhancing a site to increase its use by a particular species of bird commonly lim- its its use as habitat for other species. (For informa- tion on functions of wetlands see the articles "Wetland Hydrology, Water Quality, and Associated Functions" and "Wetland Functions, Values, and Assessment" in this volume.) Wetland creation is the construction of a wetland on a site that never was a wetland. This can be done only on a site where conditions exist that can produce and sustain a wetland. Consequently, creation is more difficult than restoration. A term commonly associated with wetland creation is "constructed." A constructed wetland is a wetland created specifically for the pur- pose of treating wastewater, stormwater, acid mine drainage, or agricultural runoff (Hammer, 1989). As used in this article, "project wetland" refers to restored or created wetlands. (For a more complete discussion of the meaning of these terms and others associated with restoration and creation, see Lewis, 1990.) CHALLENGES OF RESTORATION AND CREATION Ecological issues and physical limitations are important factors to consider when planning for wet- land restoration or creation. The relative merits of de- stroying the function of an existing wetland, or other ecosystem, in exchange for another wetland function involves the consideration of numerous questions such as: (1) Which is more important, the existing or the 1 U.S. Environmental Protection Agency (EPA). replacement function? (2) Will the proposed wetland increase wildlife diversity? (3) Is the increased diver- sity worth the loss of habitat of any endangered spe- cies? Questions of this type always arise during plan- ning for wetland restoration and creation. A well-documented example of a physical limi- tation associated with restoring a wetland can be seen along the shoreline of the Salmon River Estuary, Oreg. (Frenkel and Morlan, 1990, 1991). In the past, many high marsh wetlands along the Pacific coast were diked to remove them from tidal action. After the area was diked, the wetlands dried up and the land was used for pasture. In 1978, in an effort to restore the Salmon River Estuary to its original condition, two dikes were removed to allow the original wetlands to reestablish themselves. However, after 10 years, the resulting wet- lands (fig. 52) were not typical of other high marshes along the estuary. The land behind the dikes had sub- sided over time, and the restored wetlands were more typical of wetlands at lower elevations nearer the es- tuary (low marsh). Although the wetlands continue to evolve as sediments are trapped and deposited by the vegetation (thus raising the elevation), it might tabs another 50 years for the restored wetlands to become similar again to the original high marsh (Frenkel and Morlan, 1991). The time required and the ability to develop a fully functional soil system in project wet- lands may be major determinants of the eventual ac- ceptance or rejection of restoration and creation as management options. It is difficult to make a definitive statement about the ability to replace wetland functions. Goals for res- toration and creation projects seldom are stated and information on the existing functions of the wetlands seldom are documented. This is due, in part, to the difficulty and expense of quantifying wetland func- tions. Also, responsible monitoring during construc- tion and after completion of the project wetland is uncommon. Most information available on project wetlands is in the form of qualitative case studies. Wetland alter- ations have brought about changes in the migratory patterns of birds, local climate, and make up of plant and animal populations. Restoration and creation can help maintain the benefits of wetlands and accommodate the human need for development. Figure 52. View of a restored salt marsh in the Salmon River Estuary on the Oregon coast. (Photograph courtesy of the EPA Wetlands Research Program.) 88 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Benefits can extend beyond the wetland if care is taken in site selection. Hydrologic conditions probably are the most important determinants of wetland types and processes. DESIGNING FOR SUCCESS Much of the written material on wetland resto- ration and creation deals with "project design." Project design considers a large number of site-specific, in- terdependent factors that determine the structure and function of a wetland. Although there is no "cook- book" for restoring or creating wetlands, documents describing general approaches to restoration and cre- ation and the conditions conducive to project success are available (Garbisch, 1986; Marble, 1990; Pacific Estuarine Research Laboratory, 1990; Hammer, 1992; Maynord and others, 1992). Elements common to wetland project design are site-selection criteria, hy- drologic analysis, water source and quality, substrate augmentation and handling, plant material selection and handling, buffer zones placement, and long-term management. A brief overview of each element is pre- sented here in a sequence similar to that followed in project planning. Site selection. Sites for project wetlands often are selected on the basis of available land, or on poli- cies that require wetlands to be restored or created to compensate for nearby wetland losses (mitigation). A wetland's structure, function, and ability to persist over time are greatly influenced by its location. Wetlands in settings with limited human influence can differ greatly in structure and function from wetlands in set- tings dominated by human activities. Therefore, the present and projected land uses of the surrounding area are a consideration when selecting the site. The char- acteristics of existing wetlands, in the same general area, or in an area with similar land uses, can be used as models for what might be expected of the project wetland. Benefits that extend beyond the wetland itself can be derived from the placement of a wetland if care is taken in site selection. For example, restoration of riverbank wetlands between agricultural land and a stream can improve downstream water quality (Olson, 1992). Hydrologic analysis. Hydrologic conditions probably are the most important determinants of the type of wetland that can be established and what wet- land processes can be maintained (Mitsch and Gosselink, 1993). Elements of site hydrology that are important to maintaining a wetland are inflows and outflows of ground water and surface water, the result- ing water levels, and the timing and duration of soil saturation or flooding. One factor influencing hydrology is the configu- ration of the basin (depression) containing the wetland. High water table Low water table The position of the basin surface relative to the water table influences the degree of soil saturation and flood- ing. To ensure that standing water is present year round, many project wetlands are excavated so that the deepest part of the basin is below the lowest antici- pated water level. The slope of the basin banks deter- mines how much of the site will be vegetated and by what kinds of plants (fig. 53). This is because the slope determines how far the substrate (soil or rock mate- rial that forms the surface of the basin) will be from water and how much of the substrate has the neces- sary conditions of wetness for specific plant species (Hollands, 1990). The ability to maintain the desired plant community, therefore, is ultimately dependent on the hydrology of the site. In a properly constructed freshwater marsh, the lowest point of the wetland will be inundated to a depth and for a period long enough that emergent vegetation can persist, but not so long as to destroy the plants. Water source and quality. Although it is com- monly acknowledged that site hydrology is a major determinant of the success or failure of wetland res- toration or creation, the influence of water quality of- ten is ignored. Inputs of chemicals from the surround- ing landscape can overwhelm a wetland's ability to improve water quality and can change the character- istics of the site. For example, deicing salts are used extensively along highways and, if they enter a wet- land, can alter the productivity and composition of its plant community, possibly favoring nuisance species such as purple loosestrife (Niering, 1989). Substrate augmentation and handling. Wet- lands are characterized by hydric soils, which develop as a result of an area being saturated, flooded, or ponded long enough during the growing season to develop anaerobic (oxygen-deficient) conditions (U.S. Soil Conservation Service, 1991) (fig. 54). Most of the chemical reactions in wetlands take place in the soils, where most chemicals are stored (Mitsch and Gosselink, 1993). The soils of project wetlands are re- ceiving increased attention as studies link substrate characteristics to ecological function. Although a cre- ated wetland may be structurally similar to a natural wetland, its hydrology may differ greatly from that of the natural wetland if the permeability of the substrates differ (O'Brien, 1986). In addition to differences in permeability, soils in project wetlands commonly have a smaller amount of organic matter than soils in simi- lar natural wetlands. Because organic matter in soils stores nutrients that are critical to plant growth (Pa- High water table Low water table Figure 53. The relative position of a basin substrate, the water table, and differences in vegetation resulting from the degree of basin slope. National Water Summary Wetland Resources: RESTORATION, CREATION, AND RECOVERY 89 cific Estuarine Research Laboratory, 1990), the smaller amounts of organic matter in soils of project wetlands may limit plant growth (Langis and others, 1991). Augmenting, or mulching, the substrate of project wetlands with materials from a "donor" wet- land can increase soil organic matter and provide a source of needed plant species, microbes, and inver- tebrates. Mulching makes the substrate more condu- cive to rapid revegetation by reducing the evaporation of pore water, runoff, soil loss and erosion, and sur- face compaction and crusting (Thornburg, 1977). Mulching also can cause problems such as the intro- duction of unwanted plant species. Plant material selection and handling. Vegeta- tion is the most striking visual feature of a wetland. Be- cause of the unique and stressful conditions that de- velop in wetlands, varying from long periods of flood- ing to periodic drying, plants and animals found there have developed distinctive mechanisms to deal with these stresses and conditions. It is important to recog- nize the constraints of this unique environment when planning a project wetland. Plant communities estab- lished in project wetlands will fare better if they closely resemble communities in similar, local wetlands. To increase the likelihood of successful colonization, Garbisch (1986) suggests that project managers: Select herbaceous species that rapidly stabilize the substrate and that have potential value for fish and wildlife Select species that are adaptable to a broad range of water depths. A survey of vegetation at wet- lands of the type being created or restored can identify the conditions of "wetness" needed by species Avoid choosing only those species that are foraged by wildlife expected to use the site muskrats and geese have been known to denude sites Avoid committing significant areas of the site to species that have questionable potential for suc- cessful establishment In addition, Stark (1972) suggests the selection of "low maintenance" vegetation. Buffer zone placement. Protective measures are needed for many restored and created wetlands, par- ticularly in urbanized areas. This protection can take the form of an undeveloped, vegetated band around the wetland; a fence or barrier; or a lake or sediment ba- sin. This buffer between the wetland and surrounding land is desirable; however, the characteristics of an appropriate vegetated buffer are not well defined. Al- though composition is important, width is the most frequently cited characteristic of an adequate buffer zone. Requirements for both composition and width are dependent upon the adjacent land uses, their po- tential effect on the functions of the wetland, and the requirements of the animals that will use the wetland and buffer area. Buffers are used to: Deter predators from entering wetlands Trap and prevent undesirable materials from enter- ing the wetland through runoff from the sur- rounding landscape Provide habitat for wildlife that depend on uplands in addition to wetlands for part of their life cycle Long-term management. Careful monitoring of newly established wetlands and the ability to make mid-course corrections are critical to long-term suc- Figure 54. Scientist checking to see if a soil sample has the unique coloration typical of wetland (hydric) soils. (Photograph courtesy of the EPA Wetlands Research Program). cess. However, few project sponsors have been will- ing to assume long-term responsibility for managing these new systems (Kusler and Kentula, 1990b). Be- cause of this, project wetlands that are designed to be self-sustaining or self-managing will have the best chance of survival. The installation of control struc- tures, such as tide gates or pumps, that will require maintenance and are subject to vandalism could be dis- advantageous to the life of the project wetland. EVALUATION OF SUCCESS One of the most vexing aspects of wetland resto- ration and creation projects is defining success, pri- marily because there is no generally accepted defini- tion. This is true for many reasons lack of clearly stated objectives, lack of long-term monitoring (Kusler and Kentula, 1990b), and the subjective point of view of the definer (Roberts, 1993). The vast ma- jority of project wetlands are ecologically young 10 years of age or less. The lack of information on eco- logically mature projects limits the ability to predict whether or not the functions of project wetlands can replace the functions of natural wetlands. Neverthe- less, the results of ongoing research and good profes- sional judgment can be used to provide insight into the selection of projects that have a high probability of success. Various attempts have been made to define suc- cess criteria for wetland projects. The earliest criteria assumed that if conditions were correct for the estab- lishment of wetland vegetation, then other ecological functions would either be present or develop over time. Now, it is known that a site "green" with vegetation does not necessarily mean success, and the standards by which projects are judged are more likely to be tied to wetland functions. The Wetlands Research Program of the U.S. En- vironmental Protection Agency (EPA) is developing an approach to establish quantitative performance crite- Chemicals from the surrounding landscape can overwhelm a wetland's ability to improve water quality. Plants in project wetlands fare better if they closely resemble those in similar, local wetlands. 90 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES It is still uncertain if a full suite of wetland functions can be replaced. ria for project wetlands. In this approach, groups of natural wetlands serve as reference sites against which project wetlands are judged. For example, Zedler (1993) uses reference data from natural marshes be- ing used by clapper rails (an indigenous bird species) to define criteria that can be used to judge the suitabil- ity of restored and created habitat for the birds. Older project wetlands also are used as reference sites against which to judge newer project wetlands, both to verify that development is as expected and to identify devel- opmental patterns that may have resulted from changes in project design (Kentula and others, 1992). This approach is designed to produce results that are region- ally applicable to wetland protection and management. One tool for comparing the characteristics of project wetlands with similar, naturally occurring wet- lands is a performance curve (fig. 55). Functions in a group of restored wetlands can be expected to increase gradual ly with time to a point of maturity at which time the level of function has stabilized. The mean level of function in mature project wetlands is generally less than that for natural wetlands. Rate and time of matu- ration and functional level at maturity will differ from project to project, depending on the type of wetland being restored. The curve provides information on when to monitor, how restored wetlands typically de- velop, and when project goals have been met. Changes in the characteristics of project wetlands can be ex- pected in response to the maturation process, but also in response to changes in the environment. Informa- tion on the development of project wetlands and simi- lar natural wetlands helps managers determine whether an observed change is typical for a particular year or stage of development. Over time, successful project wetlands can be ex- pected to become similar to comparable natural wet- lands. A comparison of plant diversity on project wet- lands and similar natural wetlands in Oregon (Kentula and others, 1992), Connecticut (Confer and Niering, 1o 13 £ ww z *3» pu LL. LL. LU z5 1 9 ------k-r^---*-^---^^--*-- . x"' \ * "*" * x x Maturity - x ^ * x $ s t x f / _^< «. EXPLANATION Mean level of function For natural wetlands at a point in time For restored wetlands at a point in time For natural wetlands over time For immature restored wetlands over time For mature restored wetlands over time 1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 INCREASING MONITORING TIME Figure 55. Typical performance curve illustrating the comparison of groups of natural wetlands and restored wetlands of the same type and similar size in the same land-use setting. (Source: Modified from Kentula and others, 1992.) 1992), and Florida (Brown, 1991) showed that, al- though the level of diversity differs with each project, diversity tends to be higher on each project wetland than on its natural counterpart. The type of wetland studied was a pond with a fringe of freshwater marsh (fig. 56). If a project wetland develops as hoped and expected, after 2 to 5 years it probably will have a plant diversity greater than or equal to that of similar natu- ral wetlands. As competition for space and resources increases and the plants more completely cover the site, the diversity usually decreases and the plant com- munity tends to become more like that of a mature site. STATUS OF THE SCIENTIFIC KNOWLEDGE OF RESTORATION AND CREATION Current scientific knowledge about successful wetland restoration and creation has been documented in "Wetland Creation and Restoration: The Status of the Science" (Kusler and Kentula, 1990a). Although the literature on wetland restoration and creation has increased since the publication of that book, the gen- eral assessment presented still applies. Key points from the Executive Summary (Kusler and Kentula, 1990b) are discussed below. (Additional information on res- toration of aquatic systems, including wetlands, can be found in a recent publication by the National Research Council Committee on Restoration of Aquatic Ecosys- tems, 1992.) The status of scientific knowledge about wetland restoration and creation differs by wetland function, type, and location. It is still uncertain if the full suite of functions provided by a particular wetland type can be replaced. Full functional replacement has not yet been demonstrated. In the case of specific functions, the most is known about replacement of flood storage and waterfowl habitat, and the least is known about wa- ter-quality-improvement and ground-water-associated functions. The more complex the hydrology and ecol- ogy of a system, the more difficult it is to restore the system. Complete restoration might be impossible in some systems. With respect to types and locations of wetlands, the most is known about restoration and creation of intertidal salt marshes along the coasts of the United States, in particular, the tall cordgrass marshes of the Atlantic coast. However, these salt marshes comprise only about 5 percent of the total wetland area of the Nation and are only a small part of the marine and estuarine wetlands. Much less is known about restoration and cre- ation of inland freshwater wetlands, such as ponds, forested wetlands, or bogs and fens. Among these wetlands, most is known about restoration and cre- ation of those dominated by open water, such as ponds, and the associated herbaceous vegetation. Much less is known about replacing forested wetlands because of the time needed for woody vegetation to mature. Experts agree, however, that the ecosystems that are least likely to be successfully replaced are bogs and fens. These are the wetlands with deep or- ganic soils that have developed over thousands of years and that have hydrologic conditions that are difficult, if not impossible, to duplicate. National Water Summary Wetland Resources: RESTORATION, CREATION, AND RECOVERY 91 FEDERAL AGENCY RESEARCH ON WETLAND RESTORATION AND CREATION Several Federal agencies have missions, and therefore conduct research activities, that involve wet- lands. This section presents a brief overview of Fed- eral research on wetland restoration and creation. [For more information on wetland research by Federal agencies, see the publications of the Wetlands Research Program of the U.S. Army Corps of Engineers (Corps) and the article "Wetland Research by Federal Agen- cies" in this volume.] The Corps has been leading an effort to provide a reference source on current wetland research being conducted by Federal agencies. The first edition (U.S. Army Corps of Engineers, Wetlands Research Program, 1992) presents information pro- vided by the Corps, the EPA, the Soil Conservation Service (renamed Natural Resources Conservation Service in October 1994), the Forest Service, the Na- tional Marine Fisheries Service, the U.S. Fish and Wildlife Service, the Bureau of Reclamation, and the U.S. Geological Survey. The Corps surveyed over 25 agencies in 1993.1b complement the Corps' reference source, the U.S. Fish and Wildlife Service is maintain- ing the Wetland Creation/Restoration data base to pro- vide a current compilation of the published literature. A hard copy of the bibliographic material contained in the digital data base also has been produced (Schneller-McDonald and others, 1989). Federal agencies' research into wetland restora- tion and creation generally falls into two categories design implementation and performance evaluation. Major contributions on project design have been made by agencies involved in large-scale development, like the Corps (Maynord and others, 1992) and the Fed- eral Highway Administration (Marble, 1990). The EPA has focused its research on evaluation to support the agency responsibilities under Section 404 of the Clean Water Act (Zedler and Kentula, 1986; Leibowitz and others, 1992). Agencies responsible for stewardship of living resources, such as the National Marine Fisher- ies Service, have produced information that will in- crease their effectiveness in management (Thayer, 1992). The Natural Resources Conservation Service and the U.S. Fish and Wildlife Service probably will con- tribute the most information on practical, low-cost approaches to wetland restoration under the 1990 Farm Bill (Food, Agriculture Conservation and Trade Act of 1990 (P.L. 101-624) and the Wetland Reserve Program. Under these programs, thousands of wetland acres previously converted to agriculture have been restored to wetlands. To support these efforts, both agencies have produced guidelines for their field per- sonnel who are working with the farmers to restore wetlands (U.S. Soil Conservation Service, 1992; Wenzel, 1992). (For more information on legislation affecting wetlands, see the article "Wetland Protection Legislation" in this volume.) CONCLUSIONS Wetland restoration and creation is more an art than a science, and functional replacement of wetlands has not been conclusively demonstrated. At the same time, the growing body of literature and experience is Figure 56. This pond with a fringe of marsh in Portland, Oreg., is a restored wetland and is an example of the type of freshwater project wetland most common in this country. (Photograph courtesy of the EPA Wetlands Research Program.) increasing the ability to discern which projects have a high probability of restoring or replacing damaged or lost ecosystems. Two factors that most limit the effec- tive use of restoration and creation are: (1) lack of information on ecologically mature restored and cre- ated wetlands, and on the maturation process; and (2) the limited number of well designed and well con- structed project wetlands that can be used as models. In general, restoration is likely to be more suc- cessful than creation. Restoration of a damaged or destroyed wetland will have a greater chance of estab- lishing the range of prior wetland functions, includ- ing critical habitat. Also, chances are greater for the long-term persistence of a restored wetland than for one created where none existed before. Ecosystems that are least likely to be successfully replaced are bogs and fens. References Cited Brown, M.T., 1991, Evaluating constructed wetlands through comparisons with natural wetlands: Corvallis, Oreg., U.S. Environmental Protection Agency, Environmental Research Laboratory, EPA/600/3-91/058, 37 p. Confer, S.R., and Niering, W.A., 1992, Comparison of cre- ated and natural freshwater emergent wetlands in Con- necticut: Wetlands Ecology and Management, v. 2, no. 3, p. 143-156. Frenkel, R.E., and Morlan, J.C., 1990, Restoration of the Salmon River salt marshes Retrospect and perspec- tive: U.S. Environmental Protection Agency, Region 10, 142 p. ____1991, Can we restore our salt marshes? Lessons from the Salmon River, Oregon: Northwest Environmental Journal, v. 7, p. 119-135. Garbisch, E.W., Jr., 1986, Highways and wetlands Com- pensating wetland losses: McLean, Va., Federal High- way Administration, Office of Implementation, Contract Report DOT-FH-11-9442, 60 p. Hammer, D.A., ed., 1989, Constructed wetlands for waste- water treatment Municipal, industrial, and agricul- tural: Chelsea, Mich., Lewis Publishers, Inc., 831 p. Hammer, D.A., 1992, Creating freshwater wetlands: Chelsea, Mich., Lewis Publishers, Inc., 298 p. Restoration is likely to be more successful than creation. 92 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Hollands, G.G., 1990, Regional analysis of creation and res- toration of kettle and pothole wetlands, in Kusler, J.A., and Kentula, M.E., eds., Wetland creation and restora- tion The status of the science: Washington, D.C., Is- land Press, p. 281-298. Kentula, M.E., Brooks, R.P., Gwin, S.E., Holland, C.C., Sherman, A.D., and Sifneos, J.C., 1992, An approach to improving decision making in wetland restoration and creation: Washington, D.C., Island Press, 151 p. Kusler, J.A., and Kentula, M.E., eds., 1990a, Wetland cre- ation and restoration The status of the science: Wash- ington, D.C., Island Press, 591 p. Kusler, J.A., and Kentula, M.E., 1990b, Executive summary, in Kusler, J.A., and Kentula, M.E., eds.. Wetland cre- ation and restoration The status of the science: Wash- ington, D.C., Island Press, p. xvii-xxv. Langis, Rene, Zalejko, M.K., and Zedler, J.B., 1991, Nitro- gen assessments in a constructed and natural salt marsh of San Diego Bay: Ecological Applications v. 1, p. 40- 51. Leibowitz, S.G., Preston, E.M., Arnaut, L.Y., Detenbeck, N.E., Hagley, C.A., Kentula, M.E., Olson, R.K., Sanville, W.D., and Sumner, R.R., 1992, Wetland re- search plan An integrated risk-based approach: Corvallis, Oreg., U.S. Environmental Protection Agen- cy, Environmental Research Laboratory, EPA/600/R-92/ 060, 123 p. Lewis, R.R., Jr., 1990, Wetland restoration/creation/enhance- ment terminology Suggestions for standardization, in Kusler, J.A., and Kentula, M.E., eds., Wetland creation and restoration The status of the science: Washington, D.C., Island Press, p. 417^23. Marble, A.D., 1990, A guide to wetland functional design: McLean, Va., Federal Highway Administration Report Number FHWA-IP-90-010, 222 p. Maynord, S.T., Landin, M.C., McCormick, J.W., Davis, J.E., Evans, R.A., and Hayes, D.F., 1992, Design of habitat restoration using dredged material at Bodkin Island, Chesapeake Bay, Maryland: Vicksburg, Miss., U.S. Army Corps of Engineers, Waterways Experiment Sta- tion, Wetlands Research Program Technical Report WRP-RE-3, 33 p. + tables and figures. Mitsch, W.J., and Gosselink, J.G., 1993, Wetlands (second edition): New York,Van Nostrand Reinhold Company, Inc., 722 p. National Research Council Committee on Restoration of Aquatic Ecosystems Science, Technology, and Public Policy, 1992, Restoration of aquatic ecosystems Sci- ence, technology, and public policy: Washington. D.C., National Academy Press, 552 p. Niering, W.A., 1989, Effects of stormwater runoff on wet- land vegetation: Proceedings of the Stormwater Confer- ence, Southborough, Mass., New England Institute for Environmental Studies, p. 1-38. O'Brien, A.L., 1986, Hydrology and the construction of a mitigating wetland, in Larson, J.S., and Neill, Christo- pher, eds.. Mitigating freshwater wetland alterations in the glaciated northeastern United States An assess- ment of the science base: Amherst, Mass., Environmen- tal Institute, University of Massachusetts, Publication 87-1. p. 83-200. Olson, R.K., ed., 1992, Special Issue The role of created and natural wetlands in controlling nonpoint source pol- lution: Ecological Engineering, v. 1, no. 1/2, p. 1-170. Pacific Estuarine Research Laboratory, 1990, A manual for assessing restored and natural coastal wetlands with examples from southern California: LaJolla, Calif., Cali- fornia Sea Grant Report Number T-CSGCP-021, 105 P- Roberts, L., 1993, Wetlands trading is a losing game, say ecologists: Science, v. 260, no. 5116, p. 1,890-1,892. Schneller-McDonald, Karen, Ischinger, L.S., and Auble, G.T., 1989, Wetland creation and restoration Description and summary of the literature: Washington, D.C., U.S. Fish and Wildlife Service Biological Report 89,66 p. + database records. Stark, Nellie, 1972, Low maintenance vegetation Wildland shrubs, their biology and utilization: Washington, D.C., U.S. Department of Agriculture, Forest Service, Gen- eral Technical Report INT-1. Thayer, G.W, ed., 1992, Restoring the Nation's marine en- vironment: College Park, Md., Maryland Sea Grant College, 716 p. Thornburg, A., 1977, Use of vegetation for stabilization of shorelines of the Great Lakes, in the Proceedings of the Workshop on the Role of Vegetation in Stabilization of the Great Lakes Shoreline: Ann Arbor, Mich., Great Lakes Basin Commission, p. 39-53. U.S. Army Corps of Engineers, Wetlands Research Program, 1992, National summary of ongoing wetlands research by Federal agencies (1992): Vicksburg, Miss., U.S. Army Corps of Engineers, Waterways Experiment Sta- tion, 69 p. U.S. Soil Conservation Service, 1991, Soils Hydric soils of the United States: Washington, D.C., U.S. Depart- ment of Agriculture, Soil Conservation Service Miscel- laneous Publication Number 1491. ____1992, Field handbook, Chapter 13 Wetland resto- ration, enhancement, and creation: Washington, D.C., U.S. Department of Agriculture, Soil Conservation Service, 79 p. Wenzel, T.A., 1992, Minnesota wetland restoration guide: Minneapolis, Minn., Minnesota Board of Water and Soil Resources. Zedler, J.B., 1993, Canopy architecture of natural and planted cordgrass marshes Selecting habitat evaluation crite- ria: Ecological Applications, v. 3, no. 1, p. 123-138. Zedler, J.B., and Kentula, M.E., 1986, Wetlands research plan: Corvallis, Oreg., U.S. Environmental Protection Agency, Environmental Research Laboratory, EPA/600/ 3-86/009, 118 p. FOR ADDITIONAL INFORMATION: Mary E. Kentula, Wetlands Research Program, U.S. Environmental Protection Agency, Environmental Research Laboratory, Corvallis, OR 97333 U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources: RESTORATION, CREATION, AND RECOVERY 93 Restoration, Creation and Recovery of Wetlands Effects of Hurricane Andrew (1992) on Wetlands in Southern Florida and Louisiana By John K. Lovelace 1 and Benjamin R McPherson 1 Hurricane Andrew was a small but powerful storm that caused massive destruction along a path through southern Florida and south-central Louisi- ana in late August 1992 (fig. 57). Rainfall associated with Andrew was light for a hurricane because of the small size and rapid forward movement of the storm. However, rainfall totals of more than 7 inches were recorded for the storm period in southeastern Florida and Louisiana: a high of 11.9 inches was recorded in Hammond, La. (Rappaport, 1992). Maximum sus- tained windspeeds of 141 mph (miles per hour), with gusts of 169 mph, were recorded on August 24, just before landfall in Florida (Rappaport, 1992). A storm surge of about 17 feet above sea level was recorded at Biscayne Bay, Fla. (fig. 58) and about 9 feet near Terrebonne Bay in south-central Louisiana (fig. 59). Hurricane Andrew originated in the North Atlan- tic Ocean, moved westward over the Bahamas, and made landfall near the southern tip of Florida on the morning of August 24. After passing over the Florida Everglades, the storm proceeded in a northwesterly direction across the Gulf of Mexico and made land- fall in south-central Louisiana at Point Chevreuil on the morning of August 26. Andrew deteriorated rap- idly after landfall in Louisiana and was downgraded to a tropical depression on August 27. The remnants of Andrew proceeded on a northeasterly path, produc- ing severe weather throughout the Southeastern States (Rappaport, 1992). Hurricane Andrew moved across southern Florida at an average forward speed of 18 mph (Na- tional Oceanic and Atmospheric Administration, 1992). As it crossed southern Florida, Andrew left a path of destruction 25 miles wide and 60 miles long (Gore, 1993). Andrew left a path of destruc- tion 25 miles wide and 60 miles long TEXAS EXPLANATION ^H Tropical-storm-force winds L__j Hurricane-force winds Hurricane passage Storm passage 25 6am Date and time X %/ * <* & V *yy % $ 300 MILES 300 KILOMETERS *- % i;^/^* *' x y <ry^* Figure 57. Storm path and areal extent of tropical-storm- and hurricane-force winds produced by Hurricane Andrew, August 1992. (Source: Data from National Oceanic and Atmospheric Administra- tion, National Weather Service. Landsat images (photographs) from U.S. Geological Survey, EROS Data Center.) August 23,1992 4:53 pm August 24,1992 4:41 pm August 25,1992 4:29 pm August26,1992 4:17pm U.S. Geological Survey. 94 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Hollywood * SOUTHERN FLORIDA . MAP AREA Figure 58. Storm-surge elevations, in feet above sea level, at selected points along the coast of Florida; < indicates less than. (Source; Data from U.S. Geological Survey files.) Hurricane Andrew passed through the heart of the largest wetlands in the United States, the Florida Ev- erglades. (See article "Florida Wetland Resources" in the State Summaries part of this volume.) Perhaps the most dramatic effect of the storm's passage through these wetlands was the major structural damage to trees caused by the strong winds. The storm passed directly over Biscayne National Park and Everglades National Park, knocking down or severely damaging mangrove trees on about 70,000 acres of wetlands in the two parks. Within the storm's path, virtually all large trees located in hammock areas (islands of dense, tropical undergrowth), typically hardwoods, were defoliated and about 25 percent of the trees were windthrown or badly broken. About one-fourth of the royal palms and one-third of the pine trees in Ever- glades National Park were broken or damaged by the winds (fig. 60). Damage to woody vegetation was most severe near the eye of the storm where winds were the strongest (Davis and others, 1994). However, within 20 days surviving trees and shrubs had sprouted new growth (Alper, 1992). The storm appeared to have only minor effects on the interior freshwater wetlands of The Ever- glades, which are composed mainly of sawgrass. Nearly all post-storm (August 28 to September 17, 1992) water-quality properties sampled by the South Florida Water Management District were within the range of pre-storm values. These properties included Positive surge Negative _ surge -SEA LEVEL - 22 23 24 25 26 27 28 29 30 B 22 23 24 25 26 27 28 29 30 NA/V 22 23 24 25 26 27 28 29 30 DAYS, IN AUGUST 1992 MISSISSIPPI ALABAMA . SOUTHERN LOUIS/ANA ""* Figure 59. Storm-surge elevations, in feet above or below sea level, at selected points along the coast of Louisiana. Graphs indicate water levels at sites A, Vermilion Bay, near Cypremont Point; B, Wax Lake outlet, at Coleman; C, Houma Navigation Canal, at Dulac. (Source: Data from U.S. Geological Survey files.) National Water Summary Wetland Resources: RESTORATION, CREATION, AND RECOVERY 95 turbidity, color, ammonia, and dissolved phosphate. Wind-heaped, vegetative marsh debris was evident along the edges of some forested islands, and the characteristic periphyton mat (group of stalkless mi- cro-organisms that live attached to surfaces project- ing from the bottom of freshwater bodies) was absent or altered in structure. However, much of The Ever- glades' marsh appeared undamaged by the storm. A significant effect of the wind in the freshwater wet- lands was the destruction of, or damage to, about 80 percent of the hydrologic and meteorologic monitor- ing stations located along the storm's path (Davis and others, 1994). The hurricane had little effect on wildlife in The Everglades. Thirty-two deer wearing radio collars for a National Park Service study survived the hurricane, and the releafing of vegetation provided them with food and cover. Adult alligators appeared unaffected, but nests and young may have been adversely affected. Most wading birds survived; estimates of pre- and post-storm populations were similar, and about nor- mal for the late-summer wet season (Davis and oth- ers, 1994). In the marine environment, the major effects of the hurricane were changes in nearshore water qual- ity, patches of intense bottom scouring, and beach overwash. Dramatically increased turbidity persisted in some areas for at least 30 days, particularly in western Biscayne Bay where mangrove peat soils continued to break down and enter the water. In north- eastern Florida Bay, at the southern edge of the af- fected area, concentrations of ammonia, dissolved phosphate, and dissolved organic carbon increased dramatically. Phytoplankton (microscopic drifting aquatic plants) blooms added to the increased turbid- ity and, combined with low dissolved-oxygen concen- trations, could have had severe effects on fish and in- vertebrate populations- In addition, fuel from hun- dreds of damaged boats and marina fuel tanks in Biscayne Bay continued to discharge into the water for at least 27 days after the hurricane had passed (Davis and others, 1994). In Louisiana, the storm surge produced signifi- cant flooding in a few populated areas in the south- ern part of the State. However, there was no major flooding of inland rivers. The greatest surge was east of the point of landfall, where the counterclockwise rotation of winds, combined with forward motion of the hurricane, pushed water northward (fig. 59). An- drew also produced a negative surge of as much as 3 feet below sea level along the coast from about 10 miles west of landfall to the Texas State line, as the counterclockwise winds west of the hurricane's eye pushed water away from the shore. Because the hur- ricane was moving in a northwesterly direction at the time of landfall, areas near landfall experienced a negative surge as the hurricane was to the southeast, then a positive surge as the hurricane moved past and was to the west. After making landfall in Louisiana, Hurricane Andrew curved back towards the northeast, passing over the Atchafalaya River Basin, which contains the largest hardwood swamp (1.5 million acres) in the United States, and Louisiana's largest palustrine wet- land. (See article "Louisiana Wetland Resources " in this volume.) In parts of the basin, the storm severely Figure 60. Hammock (top) and pine forest (bottom) in Everglades National Park, Fla., after Hurricane Andrew, September 1992. (Photo- graphs by Benjamin F. McPherson, U.S. Geological Survey.) damaged trees, primarily willows and some cypress. Near the coast, about 80 percent of the trees were knocked down; about 20 miles inland, the estimates were about 30 percent. With the loss of trees, an esti- mated 50 to 75 percent of the young squirrels in the area, those produced during the second litter of the year, died. The storm had little effect on deer (David Morrison, Louisiana Department of Wildlife and Fisheries, oral commun., 1993). In the Atchafalaya River Basin, an estimated 182 million freshwater fish perished because of the resuspension of anaerobic bottom materials in the water column (fig. 61). Most of the fish probably died during the first 24 hours after the storm as toxic hy- drogen sulfide was released from bottom sediments, and decaying organic matter consumed dissolved oxy- gen, causing fish to asphyxiate (Gary Tilyou, Loui- siana Department of Wildlife and Fisheries, oral commun., 1993). After the storm, U.S. Geological Survey personnel measured dissolved-oxygen con- centrations of less than 1 mg/L throughout most of the basin, in an area extending northward more than 60 miles from the coast (Charles Demas, U.S. Geo- logical Survey, oral commun., 1993). Dissolved-oxy- gen concentrations in the upper water column of larger water bodies in the Atchafalaya River Basin generally range from 3 to 6 mg/L during summer months (Dennis K. Demecheck, U.S. Geological Sur- vey, oral commun., 1994). During the 2 weeks follow- Hurricane Andrew passed through the heart of the largest wetlands in the United States. 96 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES Figure 61 . Dead fish in the Atchafalaya River Basin, La., September 2, 1992. (Photograph by Charles R. Demas, U.S. Geological Survey.) An estimated 9.4 million saltwater fish valued at $7.8 million were killed by the storm. ing the hurricane, fishkills were caused primarily by the movement of water containing low concentrations of dis- solved oxygen into previously unaf- fected water (Gary Tilyou, Louisiana Department of Wildlife and Fisheries, oral commun., 1993). The value of freshwater fish killed was about $160 million, most of which was attributed to the estimated 29,000 paddlefish that died. (The paddlefish is an endangered species and its valuation is based on the $2,500 per-fish fine for killing paddle- fish.) Estimates of the number of other species killed (in millions) include shad, 100; bream, 23; crappie, 7; large- mouth bass, 5; fresh-water drum, 11; buffalo, 12; catfish, 11; and carp, 1 (Harry Blanchet, Louisiana Depart- ment of Wildlife and Fisheries, oral commun., 1993). In the coastal waters, an estimated 9.4 million saltwater fish valued at $7.8 million were killed by the storm. The exact causes of death are uncertain, but popular theories include suffocation, caused by clogging of gills by sediment, and gas-bubble disease, caused by the formation of nitrogen bubbles in the fish's bloodstream due to increased pressure. Most of the fish were found along a band of coastline about 5 miles long, just southeast of the point of landfall. Species killed (in millions) include menhaden, 5.7; mullet, 0.9; croaker, 0.9; spotted sea trout, 0.2; sea catfish, 0.4; black drum, 0.03; and red drum, 0.02 (Harry Blanchet, Louisiana Department of Wildlife and Fisheries, oral commun., 1993). Large segments of Louisiana's coastal marsh, primarily in Terrebonne and St. Mary Parishes, were damaged. About 40 percent of the Nation's tidal wet- lands are located on Louisiana's gulf coast (S.J. Wil- liams, 1993). A substantial part of these wetlands is composed of fresh and intermediate marsh (Chabreck and Linscombe, 1978). Much of this marsh is "floatant" (a floating type of marsh). The marsh is said to float because partially decomposed organic matter and intertwining plant roots form a dense mat that rises and falls with the water level. The roots of the plants that make up the mat are unattached, or only partly attached, to the bottom (Lee Foot, U.S. Fish and Wildlife Service, oral commun., 1993). The marsh suffered substantial damage caused by wind, tide, and wave action. Three specific kinds of damage were identified: Compressed marsh, where a net decrease in sur- face area results from the marsh being pushed together, somewhat like an accordion closing Marsh balls, which are created by the marsh be- ing piled, rolled, or otherwise deformed to cre- ate large mounds (resulting in decreased surface area) Sediment deposition in thicknesses of as much as 10 inches, but averaging less than 1 inch, which killed vegetation and sank part of the floating marsh Other damage was attributed to vegetative scour, which resulted from large areas of attached plants having their roots torn from the bottom, and salt burn, which occurred when saline (salty) water from the Gulf of Mexico was pushed into freshwater areas, kill- ing and damaging salt-sensitive plants (Lee Foot, U.S. Fish and Wildlife Service, oral commun., 1993). About 25 square miles of coastal wetlands in Louisiana are being lost every year due to coastal erosion and wetland deterioration. Hurricane Andrew probably caused substantial immediate loss of coastal wetlands and possibly has hastened the erosion and deterioration processes already at work (Dunbar and others, 1992). References Cited Alper, Joe, 1992, Everglades rebound from Andrew: Sci- ence, v. 257, p. 1,852-1,854. Chabreck, R.H., and Linscombe, Greg, 1978, Vegetative type map of the Louisiana coastal marshes: Louisiana Department of Wildlife and Fisheries, New Orleans, La., 1 sheet. Davis, G.E., Loope, L.L., Roman, C.T., Smith, G., and Tilmont, J.T., compilers, 1994, Assessment of Hurri- cane Andrew impacts on natural and archeological re- sources of Big Cypress National Preserve, Biscayne National Park, and Everglades National Park, 15-24 September 1992: National Park Service, 158 p. Dunbar, J.B., Britsch, L.D., and Kemp, E.B., in, 1992, Land loss rates, report 3, Louisianna coastal plain: U.S. Army Corps of Engineers Technical Report GL-90-2, p. 27. Gore, Rick, 1993, Andrew aftermath: National Geographic, v. 183, no. 4, p. 2-37. National Oceanic and Atmospheric Administration, 1992, Special climate summary, Hurricane Andrew: National Oceanic and Atmospheric Administration, Southeast Regional Climate Center, Columbia, S.C., 7 p. Rappaport, Edward, 1992, Preliminary report, Hurricane Andrew, 16-28 August 1992: National Oceanic and At- mospheric Administration, National Weather Service, National Hurricane Center, Coral Gables, Fla., 28 p. Williams, S.J., Penland, Shea, and Roberts, H.H., 1993, Processes affecting coastal wetland loss in the Louisi- ana deltaic plain, in Magoon, O.T., Wilson, W.S., Con- verse, Hugh, and Tobin, L.T., eds., Coastal Zone '93- Proceedings of the Eighth Symposium on Coastal and Ocean Management, July 19-23, 1993, New Orleans, La.: New \fork, American Society of Civil Engineers, v. 1, p. 211-219. FOR ADDITIONAL INFORMATION: John K. Lovelace, U.S. Geological Survey, Louisiana District, 3535 S. Sherwood ForestBlvd., Suite 120, Baton Rouge, LA70816; Benjamin F. McPherson, U.S. Geological Survey, Tampa Subdistrict, 4710 Eisenhower Blvd., Suite B-5, Tampa, FL 33634 U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources: RESTORATION, CREATION, AND RECOVERY 97 Restoration, Creation, and Recovery of Wetlands Effects of the Great Midwest Flood of 1993 on Wetlands By James R. Kolva 1 The Great Midwest Flood of 1993 was the "most devastating flood in modern United States history" with economic damages near $20 billion. More than 50,000 homes were damaged or destroyed. The areal extent, inten- sity, and long duration of the flooding makes this event unique in the 20th century (National Oceanic and Atmospheric Administration, 1994). At least 38 people lost their lives as a result of this extreme flood (Interagency Rood- plain Management Task Force, 1994). Significant flooding in the Upper Missis- sippi River Basin began in mid-June and per- sisted into early August 1993. The areal extent of this flooding included southern Minnesota, southwestern Wisconsin, Iowa, western Illi- nois, northern Missouri, southern North Da- kota, and eastern parts of South Dakota, Ne- braska, and Kansas (fig. 62). Record flood-peak discharge was recorded at 39 streamflow-gaging stations in the Upper Mis- sissippi River Basin. Fifteen other gaging stations re- corded peak discharges exceeding previous maxi- mum known regulated discharges (Parrett and others, 1993). The recurrence interval of the peak discharge at 40 stations exceeded the 100-year flood (one-per- cent chance of occurring in any given year). Near-record and record precipitation in June and July, falling on soil already saturated by as much as twice normal early spring rains, caused these record floods. Precipitation for the period January-July 1993 totaled more than 20 inches in most of the flooded area and more than 40 inches in parts of northeast- ern Kansas and east-central Iowa (Wahl, Vining, and Wiche, 1993). Many areas received more precipita- tion in those 7 months than is normally received dur- ing the entire year. The Great Midwest Flood of 1993 was unique not only because of the record high water levels and flows and the wide areal extent, but also because of the long duration of flooding. Many rivers were above flood stage for several months. The long period of inunda- tion had significant effects on agricultural land and wetlands. The flood effects on wetlands varied in both the short term and long term. In the Upper Mississippi National Wildlife Refuge, the flooding lasted 14 weeks from April through mid-August. "This pro- longed inundation of bottom-land hardwood forest and backwater wetlands caused many tree tip-overs, scoured out ground cover and tree regeneration sites, eroded islands, destroyed emergent/submergent veg- etation beds, impacted project dikes, and thus de- stroyed most of the moist soil plants at three sites," according to James Lennartson of the U.S. Fish and Wildlife Service. The effects on wildlife populations also were severe. Many birds, including green-backed herons and red-shouldered hawks, fledged few young EXPLANATION | | Area of flooding streams Boundary of Mississippi River Basin 40° 100 200 KILOMETERS Figure 62. Areal extent of flooding in the Upper Mississippi River Basin during the Great Midwest Flood of 1993. (Source: Modified from Parrett and others, 1993). due to flooded foraging areas. Substrate disturbance and massive sedimentation affected freshwater mus- sel populations. Mussels were found buried by 1 to 2 feet of sand. Mammals were displaced from the flood plain and suffered higher than normal mortality rates on adjacent roads and railroad tracks (James Lennartson, U.S. Fish and Wildlife Service, written commun., 1994). Fishes that rely on sight to find their food were handicapped because of the increased tur- bidity. The flooding, however, had some short-term ben- efits. Many fish feed and spawn on inundated flood plains. "Ideal conditions for spring spawning fishes occur during years in which flood and temperature rise are coupled" (Scientific Assessment and Strategy Team, 1994). The evidence, particularly in the lower Missouri River flood plain, "***indicates that the magnitude and timing of the 1993 flood provided ap- propriate temperature and discharge cues for spawn- ing river-floodplain fishes" (Scientific Assessment and Strategy Team, 1994). The long-term effects of the floods are still be- ing evaluated. Fish habitat may have been improved by creation of deep scour holes and massive under- water debris piles which provide more cover (James Lennartson, oral commun., 1994). Greater-than-nor- mal sedimentation on flood plains and in wetland ponds may have introduced contaminants and excess nutrients into those areas. Exotic plants such as purple loosestrife have colonized disturbed areas and dis- placed native vegetation (Susan Hassletine, U.S. Fish and Wildlife Service, oral commun., 1994). Purple loosestrife colonies also have been observed at higher elevations than normal, probably because seeds were carried by the extremely high floodwaters to these ...the "most devastating flood in modem United States history"... ...a historically unprecedented hydrometeoro- logical event... 1 U.S. Geological Survey. 98 National Water Summary Wetland Resources: OVERVIEW OF WETLAND RESOURCES This perimeter levee surrounding the Clarence Cannon National Wildlife Refuge, Mo., damaged during the 1993 flooding, allowed excessive water to enter the refuge. (Photograph courtesy of U.S. Fish and Wildlife Service.) locations (James Lennartson, oral commun., 1994). Flood debris on flood plains has caused access prob- lems for people at some places, but provides good wildlife cover. Open wetland aquatic vegetation ap- peared to be back to normal condition during the sum- mer of 1994 (Susan Hassletine, oral commun., 1994). Wetlands commonly mitigate the effects of floods. Wetland areas can be filled with and tempo- rarily store floodwaters so that flood effects on agri- cultural and residential areas are lessened. However, wetlands have been steadily dissappearing or con- verted to other uses throughout the flood-affected area for the last two cen- turies (see "History of Wetlands in the Conterminous United States" in thi& volume). These wetlands include the river flood plains and the upland prai- rie potholes. Many upland prairie pothole wet- lands are closed flow systems, which fill with rain and melting snow and then slowly evaporate or drain through the ground-water system. Thus, they are ideal retention basins during and after intense rains because they "do not nor- mally contribute to stream flow by run- off, except during storms large enough to make the depressions fill and spill" (Scientific Assessment and Strategy Team, 1994). This seems to have been the case in the flood of 1993. All avail- able storage capacity of the wetlands was exceeded, and usually noncontrib- uting areas did contribute to runoff (In- teragency Floodplain Management Task Force, 1994). In modeling done by the Scientific Assessment and Strategy Team (1994), upland wetlands simu- lated decreased flooding in a 1-year These prairie grasses (foreground) and trees (background) were killed by the excessive water resulting from the long- term flooding of the Mississippi River in the summer of 1993 (Photograph courtesy of U.S. Fish and Wildlife Service.) event by 9-23 percent, but only by 5-10 percent in a 100-year event. Flood-plain wetlands decreased flooding 5-6 percent for 1-year floods and only 2-3 percent for the 100-year storms. The Executive Summary of the Report of the In- teragency Floodplain Management Review Commit- tee to the Administrative Floodplain Management Task Force (1994) states the effect that wetlands had on the Great Midwest Flood of 1993: The loss of wetlands and upland cover and the modification of the landscape throughout the basin over the last century and a half signifi- cantly increased runoff. *** Although upland watershed treatment and restoration of upland and bottom-land wetlands can reduce flood stages in more frequent floods (25 years and less), it is questionable whether they would have significantly altered the 1993 conditions (Interagency Floodplain Management Task Force, 1994). In conclusion, the Great Midwest Flood of 1993 was a historically unprecedented hydrometeorologi- cal event in area affected, severity of the effects, and duration of the effects. Wetlands were affected ben- eficially and detrimentally in the short and long term. The historical loss of wetlands from the basin in- creased the severity of the flood, but even if all presettlement wetlands had still existed, the flood would probably still have set records and caused bil- lions of dollars in damages. References Cited Interagency Floodplain Management Task Force, 1994, Report to the Administration Floodplain Management Task Force Sharing the Challenge: Floodplain Man- agement into the 21st Century, 191 p. National Oceanic and Atmospheric Administration, 1994, Natural disaster survey report, The Great Flood of 1993, [281 p.]. Parrett, Charles, Melcher, N.B., and James, R.W., Jr., 1993, Rood disharges in the Upper Mississippi River Basin, in Floods in the Upper Mississippi River Basin, 1993: U.S. Geological Survey Circular 1120-A, 14 p. Scientific Assessment and Strategy Team, 1994, Preliminary report to the Interagency Floodplain Management Re- view Committee of the Administration Floodplain Management T&sk Force Science for floodplain man- agement into the 21st century. Wahl, K.L., Vining, K.C., and Wiche, G.J., 1993, Precipi- tation in the Upper Mississipi River Basin January 1 through July 31, 1993, in Floods in the Upper Missis- sippi River Basin, 1993: U.S. Geological Circular 1120-B, 13 p. FOR ADDITIONAL INFORMATION: James R. Kolva, U.S. Geological Suevey, Utah District, 1745 West 1700 South, Salt Lake City, UT 84104 U.S. Geological Survey Water-Supply Paper 2425 State Summaries of Wetland Resources Horicon Marsh, Wisconsin, provides recreational opportunities for outdoor enthusiasts. (Photograph by PhilHpJ. Redman, U.S. Geological Survey.) 99 State Summaries of Wetland Resources Alabama ......................... 101 Alaska............................. 107 Arizona........................... 115 Arkansas ......................... 121 California........................ 127 Colorado......................... 135 Connecticut.................... 141 Delaware ........................ 147 Florida............................ 153 Georgia........................... 161 Hawaii............................ 167 Idaho .............................. 173 Illinois............................. 179 Indiana ........................... 185 Iowa ............................... 191 Kansas ............................ 195 Kentucky......................... 201 Louisiana ........................ 207 Maine ............................. 213 Maryland and District of Columbia ................. 219 Massachusetts ................. 225 Michigan ........................ 231 Minnesota....................... 237 Mississippi ...................... 243 Missouri.......................... 249 Montana ......................... 255 Nebraska ........................ 261 Nevada ........................... 267 New Hampshire.............. 273 New Jersey...................... 279 New Mexico ................... 285 New York ....................... 291 North Carolina................ 297 North Dakota.................. 303 Ohio............................... 309 Oklahoma....................... 315 Oregon ........................... 321 Pennsylvania................... 327 Puerto Rico ..................... 333 Rhode Island................... 339 South Carolina................ 345 South Dakota .................. 351 Tennessee ....................... 357 Texas .............................. 363 U.S. Virgin Islands .......... 369 Utah ............................... 375 Vermont.......................... 381 Virginia........................... 387 Washington .................... 393 West Virginia.................. 399 Western Pacific Islands ... 405 Wisconsin....................... 411 Wyoming........................ 417 100 National Water Summary Wetland Resources 101 Alabama Wetland Resources Wefetlands cover about 10 percent of Alabama and range in size from small areas of less than an acre scattered throughout the State to a large forested tract of more than 100,000 acres in the Mobile- Tensaw River Delta (fig. 1). Wetlands are a valuable resource be- cause they can reduce flood stages, stabilize banks, and improve water quality. Alabama's wetlands also are important nesting, breed- ing, nursing, and feeding grounds for many species offish, birds, and other wildlife and are a vital habitat for rare and endangered plants and animals and for migrating waterfowl (Shaw and Fredine, 1956). Some of the spring-fed wetlands in the State are home to threatened or endangered species such as the watercress darter, coldwater darter, and pygmy sculpin. Commercial and recreational fisheries are sustained in large part by species that spend at least part of their life cycle in wetlands. The State's wetlands and adja- cent waters also are used for recreational activities such as hunt- ing, boating, bird watching, and photography and for research and education. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deepwater habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and others, 1979). The distribution of wetlands and deepwater habitats in Alabama is shown in figure 2A\ only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (KWS) to map and inventory the Nation's wetlands. Figure 1. Cypress trees and marsh in the Mobile- Tensaw River Delta. A large tract of delta wetlands has been designated a National Natural Landmark by the National Park Service. (Photograph by Benjamin F. McPherson, U.S. Geological Survey.) At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Alabama are described below. System Palustrine. Lacustrine Riverine Estuarine.. Marine, Wetland description Nontidal and tidal-freshwater wetlands in which vegetation is predominantly trees {forested wet- lands); shrubs {scrub-shrub wetlands); persis- tent or nonpersistent emergent, erect, rooted herbaceous plants {persistent- and nonpersis- tent-emergent wetlands); or submersed and (or) floating plants {aquatic beds). Also, intermit- tently to permanently flooded open-water bod- ies of less than 20 acres in which water is less than 6.6 feet deep. Nontidal and tidal-freshwater wetlands within an intermittently to permanently flooded lake or reservoir larger than 20 acres and (or) deeper than 6.6 feet. Vegetation, when present, is pre- dominantly nonpersistent emergent plants (nonpersistent-emergent wetlands), or sub- mersed and (or) floating plants (aquatic beds), or both. Nontidal and tidal-freshwater wetlands within a channel. Vegetation, when present, is same as in the Lacustrine System. Tidal wetlands in low-wave-energy environments where the salinity of the water is greater than 0.5 part per thousand tppt) and is variable ow- ing to evaporation and the mixing of seawater and freshwater. , Tidal wetlands that are exposed to waves and cur- rents of the open ocean and to water having a salinity greater than 30 ppt. The FWS estimates that wetlands cover from 2.3 million to 3.1 million acres in Alabama (J.M. Hefner, U.S. Fish and Wildlife Ser- vice, written commun., 1992). Palustrine forested wetlands such as cypress and gum swamps, mixed hardwood forests, and wet pine flatwoods account for most of that acreage. Most of the State's forested wetlands are bottom-land forests in alluvial flood plains. Cypress and tupelo gum commonly pre- dominate in the permanently or seasonally flooded areas (swamps), whereas other trees such as swamp oak, water hickory, red maple, magnolia, sweetgum, and sycamore are more common in less fre- quently inundated areas. The loss of bottom-land forest has been extensive throughout the Southeastern United States; in some re- gions, only a small percentage of the original hardwood forests remains (Mitsch and Gosselink, 1986). Alabama has conserved a large tract of its bottom-land forest along approximately 50 miles of the Mobile-Tensaw River Delta. Other palustrine wetlands, such as shrub swamps (scrub-shrub wetlands) and seepage bogs (emergent wetlands), exist as small, isolated wetlands in the Coastal Plain of Alabama (fig. 2B), These wetlands typically are associated with ground-water seepage in swales or near the bottom of slopes. Seepage bogs support a unique and diverse flora, including at least 20 species of carnivorous plants such as pitcher plants, sundews, butterworts, and bladderworts. The bogs also are home to several species of orchids and a variety of sedges (Mohlenbrock, 1992). Fresh marshes, emergent wetlands 102 National Water Summary Wetland Resources: STATE SUMMARIES vegetated primarily by sedges, rushes, and grasses, commonly fringe ponds, reservoirs, and fresh tidal reaches of coastal rivers. Although not as abundant as palustrine wetlands, lacustrine and riverine wetlands constitute a significant proportion of Alabama's freshwater wetlands. There are few natural lakes in the Slate, but impoundments on most of the larger rivers have created many acres of lacustrine wetlands in the shallows of the reservoirs. These wetlands can be nonvegetated (unconsolidated-bottom wet- lands), vegetated by emergent plants such as American lotus and golden club that are not visible above the water surface during part of the year (nonpersistent-emergent wetlands), or vegetated by plants such as water lily or pondweed that grow on or below the water surface (aquatic-bed wetlands). Like lacustrine wetlands, riverine wetlands are nonvegetated or vegetated by nonpersistent emergent or submersed plants. Veg- etated riverine wetlands are most common in slow-flowing reaches of Coastal Plain rivers. Whereas many riverine wetlands have been converted to deepwater habitat by impoundment, riverine wetlands are still present in the shallows of the remaining streams and rivers that have not been impounded. Rocky shoals are riverine rock-bot- tom wetlands that were once more common upstream from the Fall Line in most of the State's rivers before they were impounded. These wetlands are now present only in the Cahaba River system (which remains largely unimpounded) and in a few tributaries of other, now- impounded rivers. Rocky shoals, primarily in the Cahaba River and the Little Cahaba River (a tributary), support stands of the Cahaba Hly, a spider lily that grows only in the rocky-shoal habitat (Cahaba River Society, 1992). Estuarine marshes (emergent wetlands) are extensive in Alabama's coastal waters. Salt marshes form along tidally influenced river reaches, on deltas, and on the shores of estuaries and bays. Salt marshes that are greatly influenced by seawater, such as those on A r PHYSIOGRAPHIC DIVISIONS WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown Predominantly wetland Predominantly deepwater habitat 25 50 KILOMETERS il Morga Figure 2. Wetland distribution in Alabama and physiography of the State. A, Distribution of wetlands and deepwater habitats. B, Physiog- raphy, (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 7997. B, Physiographic divisions from Fenneman, 1946; landforms data from EROS Data Center.) National Water Summary Wetland Resources: ALABAMA 103 A. Interior Low Plateaus PALUSTRINE WETLAND PALUSTRINE WETLAND B. Appalachian Plateaus PALUSTRINE WETLAND RIVERINE WETLAND E PALUSTRINE WETLANDS « PALUSTRINE WETLANDS RIVERINE WETLAND w C. Coastal Plain PALUSTRINE WETLANDS PALUSTRINE WETLANDS EXPLANATION ~- Direction of ground-water flow Average water table Forest vegetation Scrub-shrub vegetation Emergent vegetation Submersed aquatic vegetation Sand and organic deposits Figure 3. Generalized geohydrologic setting of wetlands in three physiograph- ic provinces of Alabama. A, Appalachian Plateaus. B, Interior Low Plateaus. C, Coastal Plain. Little Dauphin Island and the Fort Morgan peninsula, are vegetated predominantly by dense stands of black needlerush in areas that are flooded during extreme high tides and by smooth cordgrass in areas that are flooded more regularly (Stout, 1979). In contrast, coastal marshes in less saline habitats have a greater diversity of emergent plants (Stout, 1990). Field and others (1991) estimated that coastal salt marshes cover 25,500 acres in southern Alabama. Beds of submersed aquatic vegetation grow in the shallow waters of Mobile Bay and adjacent estu- aries; they are usually inundated except during low tide (Stout, 1990). Only the zone of these aquatic beds exposed during mean low tide is considered to be wet- land by the FWS National Wetland Inventory; most estuarine aquatic beds are in deepwater habitats. HYDROLOGIC SETTING Wetlands form where there is a persistent water supply at or near the land surface. The location and persistence of the supply is controlled by factors such as precipitation, evapotranspiration, topography, soil type, geology, runoff, and, near the coast, tides. Plen- tiful rainfall, about 55 inches per year statewide (Jeffcoat and Mooty, 1986), is an important factor contributing to wetland formation and maintenance in Alabama. Wetlands commonly form in topographi- cally low areas, in areas of impeded drainage, and at locations where the water table intersects the land surface. The movement of ground water into wetlands is controlled by hydraulic gradients (which are pri- marily determined by topography), recharge from precipitation, regional geologic structure, joints and fractures in the bedrock, and aquifer porosity, perme- ability, and thickness. For the purpose of discussing wetland hydrology, Alabama can be divided into two geohydrologic re- gions that are separated by the Fall Line (fig. 2B). The Fall Line is a regional topographic feature that marks the boundary between the ancient, resistant crystal- line rocks of the northern part of the State and the younger, softer sediments to the south. The region north of the Fall Line in Alabama lies in four physiographic provinces the Interior Low Plateaus, the Appalachian Plateaus, the Valley and Ridge, and the Piedmont (fig. 2B). This region has diverse topography; altitudes range from 200 to 2,400 feet above sea level. Wetlands in this region are com- monly associated with rivers, reservoirs, and im- poundments (as in Wheeler National Wildlife Refuge) or with springs, seeps, and solution features such as caves and sinkholes (fig. 3A and 3#). Most of the once-common rocky-shoal habitat has been destroyed by channelization and damming of rivers, except in the Cahaba River Basin and a few tributaries of other rivers (Cahaba River Society, 1992). Most of the major springs in the State are in the Interior Low Plateaus and Valley and Ridge Province, where carbonate rocks predominate. These rocks characteristically are frac- tured and cavernous and readily transmit ground water to the land surface (Chandler and Moore, 1987). Isolated wetlands have formed near springs and seeps and in sinkholes throughout the northern part of the State. Byrd Spring Swamp (also known as Byrd Spring Lake), a 650-acre wetland containing tupelo 104 National Water Summary Wetland Resources: STATE SUMMARIES gum and other bottom-land hardwoods, is a notable example of a wetland that is spring fed from a karst cave system (U.S. Fish and Wildlife Service, 1992). The region south of the Fall Line in Alabama the Coastal Plain has a gentle slope on which rivers and streams have devel- oped broad flood plains shaped by wide seasonal fluctuations in river levels. Wetlands have formed over extensive areas on these flood plains in response to an abundant supply of water from river flooding and ground-water sources. The hydrology of flood-plain wetlands is typically dominated by river water levels that respond to basinwide climatic conditions (Winter and Woo, 1990). In late winter and early spring, annual flooding by rivers and streams can inundate the entire flood plain to depths of several feet or more. Natural levees along rivers and streams trap water in the flood plain and reduce surface runoff (Hofstetter, 1983). Water trapped in flood- plain wetlands is lost primarily by evapotranspiration and as ground- water recharge (Winter and Woo, 1990). During much of the year, water levels in the flood plains are at or below the land surface, except in ponds, depressions, and sloughs, which can retain surface water year round. Wetlands on flood plains also are sustained by ground water (fig. 3C). A rise in river stage causes water to go into bank storage, which results in a rise in ground-water levels in the flood plain. Ground-water inflow from adjacent uplands also can be an impor- tant source of water to flood-plain wetlands because flood plains are topographically low and are a natural place for discharge from ground-water flow systems (Winter and Woo, 1990). On flood plains near the coast, river discharge combined with tidal action causes flooding and temporary storage of freshwater in large areas of wetlands, such as those in the Mobile-Tensaw River Delta (fig. 3C). The temporary storage affects the timing and size of freshwater influx into Mobile Bay, which is critical in maintain- ing optimal salinities in the bay. Temporary storage of freshwater in the delta wetlands also improves the quality of the water that flows into the bay by reducing nutrient and sediment loads and by increas- ing organic detrital loads that serve as a food source for many es- tuarine organisms (Dardeau and others, 1990; Stout, 1990). Estuarine wetlands form where freshwater and saltwater mix and can be subject to widely varying salinity caused by tidal fluc- tuations and by seasonal and annual differences in freshwater in- put that result from climate variation. Plants and animals of estua- rine wetlands must be adapted to constantly changing hydrologic, salinity, and nutrient-availability regimes. Owing to the differing physiological tolerances of wetland plants and animals, wetland communities develop in identifiable zones in response to those fac- tors. TRENDS Alabama has lost as much as 50 percent of its wetlands in the last 200 years (Dahl, 1990). In predevelopment times, wetlands covered about 7.6 million acres of the area that is now Alabama. Recent estimates of the remaining wetland acreage in Alabama range from 2.3 million to 3.1 million acres (J.M. Hefner, U.S. Fish and Wildlife Service, written commun., 1992) to about 3.8 million acres (U.S. Department of Agriculture, 1985). Differences in the estimates possibly reflect differences in inventory terminology or techniques. Alabama lost about 10 percent of its interior wetlands from 1956 through 1979 (U.S. Fish and Wildlife Service, 1992). Primary causes for the loss of the interior wetlands were agricultural con- version of wetlands to croplands, conversion of bottom-land hard- wood forests to pine culture, and inundation caused by reservoir construction. Alabama lost about 69 percent of its coastal freshwater marsh and 29 percent of its estuarine marsh from 1955 through 1979. Pri- mary reasons for the loss of these coastal wetlands were industrial and commercial development, residential development, erosion and subsidence, and natural succession from wetlands to uplands (Roach and others, 1987). Much of the loss of coastal wetlands occurred in the Mobile Bay area, where the loss was due to direct and indirect effects of dredging (Duke and Kruczynski. 1992). Stout (1979) es- timated that about 6,000 acres of marshland in the bay have been destroyed and about 2,200 acres of marshland created by deposi- tion of dredged material. Cumulative effects of alterations of all kinds on the Mobile Bay ecosystem resulted in a loss of more than 10,000 acres of emergent estuarine marsh and probably more than 50 percent of the submerged aquatic vegetation in the bay between 1955 and 1979 (Watzin and others, in press). The FWS recently evaluated wetland changes in upper Mobile Bay (Watzin and others, in press). The evaluation revealed no addi- tional loss of estuarine-marsh acreage since 1979 and reported a substantial (75 percent) increase in freshwater marsh from 1979 to 1988. The increase in freshwater marsh was attributed to growth of emergent vegetation in disposal areas and ditches and to mapping errors in earlier inventories. About 1,200 acres (2.7 percent) of for- ested wetlands in the upper Mobile Bay area were lost or converted to scrub-shrub wetlands between 1979 and 1988. A major cause of the conversions was clearcutting associated with timber harvest. Losses were due largely to creation of impoundments and commer- cial development. Wetland regulations currently (1993) in effect generally allow wetland destruction only when mitigated by wetland enhancement or creation. The effectiveness of these measures in slowing wetland loss will depend upon enforcement of and compliance with the mitigation requirements. The effectiveness of wetland mitigation in sustaining the ecological functions of wetlands remains in question (Stout, 1979; Alabama Department of Environmental Management, 1992). CONSERVATION Many government agencies and private organizations partici- pate in wetland conservation in Alabama. The most active agencies and organizations and some of their activities are listed in table 1. Federal wetland activities. Development activities in Ala- bama wetlands are regulated by several Federal statutory prohibi- tions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Harbors Act; the 1972 Clean Water Act and amendments; the 1985 Food Security Act; the 1990 Food, Agriculture, Conservation, and Trade Act; the 1986 Emergency Wetlands Resources Act; and the 1972 Coastal Zone Management Act. Section 10 of the Rivers and Harbors Act gives the U.S. Army Corps of Engineers (Corps) authority to regulate certain activities in navigable waters. Regulated activities include diking, deepening, filling, excavating,and placing of structures. The related section 404 of the Clean Water Act is the most often-used Federal legislation protecting wetlands. Under section 404 provisions, the Corps issues permits regulating the discharge of dredged or fill material into wetlands. Permits are subject to review and possible veto by the U.S. Environmental Protection Agency (EPA), and the FWS has review and advisory roles. Section 401 of the Clean Water Act grants to States and eligible Indian Tribes the authority to approve, apply conditions to. or deny section 404 permit applications on the basis of a pro- posed activity's probable effects on the water quality of a wetland. Most farming, ranching, and silviculture activities are not sub- ject to section 404 regulation. However, the "Swampbuster" provi- sion of the 1985 Food Security Act and amendments in the 1990 Food, Agriculture, Conservation, and Trade Act discourage (through financial disincentives) the draining, filling, or other alteration of wetlands for agricultural use. The law allows exemptions from pen- alties in some cases, especially if the farmer agrees to restore the National Water Summary Wetland Resources: ALABAMA 105 Table 1 . Selected wetland-related activities of government agencies and private organizations in Alabama, 1993 [Source: Classification of activities is generalized from information provided by agencies and organizations. , agency or organization participates in wetland-related activity;..., agency or organization does not participate in wetland-related activity. MAN, management; REG. regulation; R&C, restora- tion and creation; LAN, land acquisition; R&D, research and data collection; D&l, delineation and inventory) Agency or organization FEDERAL Department of Agriculture Consolidated Farm Service Agency............................ Forest Service................................................................. Natural Resources Conservation Service ................. Department of Commerce National Oceanic and Atmospheric Administration Department of Defense Army Corps of Engineers .............................................. Military reservations ..................................................... Department of the Interior Fish and Wildlife Service .............................................. Geological Survey.......................................................... National Biological Service.......................................... National Park Service ................................................... Environmental Protection Agency .................................. Tennessee Valley Authority .............................................. STATE Department of Conservation and Natural Resources . Department of Economic and Community Affairs ........ Department of Environmental Management................. Geological Survey of Alabama ........................................ Marine Environmental Sciences Consortium ............... SOME COUNTY AND LOCAL GOVERNMENTS .............. PRIVATE ORGANIZATIONS The Nature Conservancy.................................................. Coastal Land Trust.............................................................. altered wetland or other wetlands that have been converted to agri- cultural use. The Wetlands Reserve Program of the 1990 Food, Agriculture, Conservation, and Trade Act authorizes the Federal Government to purchase conservation easements from landowners who agree to protect or restore wetlands. The Consolidated Farm Service Agency (formerly the Agricultural Stabilization and Con- servation Service) administers the Swampbuster provisions and Wet- lands Reserve Program. The Natural Resources Conservation Service (formerly the Soil Conservation Se-vice) determines com- pliance with Swampbuster provisions and assists farmers in the iden- tification of wetlands and in the development of wetland protection, restoration, or creation plans. The 1986 Emergency Wetlands Resources Act and the 1972 Coastal Zone Management Act and amendments encourage wetland protection through funding incentives. The Emergency Wetland Resources Act requires States to address wetland protection in their Statewide Comprehensive Outdoor Recreation Plans to qualify for Federal funding for State recreational land: the National Park Ser- vice provides guidance to States in developing the wetland compo- nent of their plans. Coastal States that adopt coastal-zone manage- ment programs and plans approved by the National Oceanic and Atmospheric Administration (NOAA) are eligible for Federal fund- ing and technical assistance through the Coastal Zone Management Act. Federal agencies are responsible for the proper management of wetlands on public land under their jurisdiction. In Alabama, the U.S. Forest Service manages wetlands in five National Forests, which contain 636,476 acres of land and more than 400 miles of rivers (Alabama Department of Economic and Community Affairs, 1991). The FWS manages 55,000 acres on five National Wildlife Refuges in the State, of which about 29,000 acres are wetlands (Frank Dukes, U.S. Fish and Wildlife Service, oral commun., 1992). The Corps manages 14 impoundments in the State and more than 100 public-use areas (U.S. Army Corps of Engineers, 1981). Mili- tary bases in Alabama cover an area of about 400,000 acres, some of which contain wetlands. The Sanctuaries and Reserves Division of NOAA, in cooperation with the State of Alabama, manages the Weeks Bay National Estuarine Research Reserve. The Tennessee Valley Authority (TVA) maintains 3,750 acres of managed wetlands in northern Alabama (Wes James, Tennessee Valley Authority, oral commun., 1993). The Wildlife and Natural Heritage Resources Section of TVA develops and implements conservation and manage- ment strategies to ensure protection of wildlife and natural heritage resources on TVA lands and promotes protection and enhancement of such resources elsewhere in the region. The Natural Heritage Resources Section, in cooperation with State wildlife-management agencies and the FWS, operates projects that provide critical wet- land habitats that support migratory waterfowl and other important wetland species. Although it does not manage wetlands, EPA'S wetland-research programs facilitate wetland management and conservation in Ala- bama. The EPA, in cooperation with State and other Federal agen- cies, is assessing coastal wetlands in the State as part of its Gulf of Mexico Program. The ERA and FWS are conducting a demonstration project that will map changes in wetlands in Mobile Bay and the lower Mobile-Tensaw River Delta. State wetland activities. Although Alabama currently (1993) has no comprehensive wetland-protection program, the State is as- sessing the need for a wetlands policy. Several State agencies ac- tively participate in aspects of Federal programs, and some wetlands are protected under State programs. The Alabama Department of Economic and Community Af- fairs is responsible for planning policies that protect the State's water resources, including wetlands. The Department's newly formed Office of Water Resources has initiated a 3-year study to be com- pleted in 1995 that will address protection of wetlands and other water resources in the State. The Department also addresses wet- land issues in its Statewide Comprehensive Outdoor Recreation Plan in response to section 303 of the Federal Emergency Wetlands Re- sources Act of 1986. The Alabama Department of Environmental Management manages wetlands in Alabama's coastal zone through its regulatory authority under the Alabama Coastal Zone Management Act and through its authority to issue section 401 water-quality certification. The Department identifies wetlands and submersed grassbeds as coastal resources for which effects from any regulated uses must be considered. This activity includes review of all State and Fed- eral permitting activities for the coastal zone of the State and pri- marily, in the case of wetlands, section 404 dredge-and-fill permits and Rivers and Harbors Act navigable-water permits issued by the Corps (Alabama Department of Environmental Management, 1992). Alabama's Coastal Zone Management program defines the coastal zone as that part of the State where the land surface is less than 10 feet above sea level. However, Rathburn and others (1987) reported that approximately 28 percent of Alabama's coastal wetlands are in areas that are higher than 10 feet and, thus, are excluded from pro- tection under the Coastal Zone Management program. Mitigation for wetland losses caused by approved projects is required in the coastal zone. A review of some of these coastal miti- gation projects indicated that, of 14 projects, 6 could not be evalu- ated, 3 were successful, 2 were partially successful, and 3 were fail- ures (Alabama Department of Environmental Management, 1992). The Department of Environmental Management regulates dredge-and-fill activities in wetlands that are not in Alabama's coastal zone solely through the State's authority to issue section 401 water-quality certification under the Clean Water Act and through the Nonpoint Source Discharge Management Program. Other ac- 106 National Water Summary Wetland Resources: STATE SUMMARIES tivities that might affect wetlands, such as draining or logging op- erations that do not result in significant wetland fill, are not regu- lated. Wetland waters are considered to be waters of the State in the Alabama Water Pollution Control Act but are not defined or protected by the act for their inherent value (Alabama Department of Environmental Management, 1992). The Alabama Department of Conservation and Natural Re- sources comments on section 404 permit applications and on local land-use issues to call attention to potential effects on wildlife. The Department manages, regulates, and acquires land (including wet- lands) for wildlife-management areas. State parks, and for other State recreational lands. The Department also will administer a new pro- gram, "Forever Wild," that has the objective of acquiring land for protection, recreation, education, and scientific research. Private wetland activities. Private organizations in Alabama are important advocates for wetlands. These organizations inform the public on wetland issues, organize citizen networks, and lobby for wetland protection. The Alabama Conservancy, the Coastal Land Trust, the Sierra Club, the National Audubon Society, the Alabama Wildlife Federation, and the Cahaba River Society are involved in State wetland issues. The Nature Conservancy is active in the acquisition and pro- tection of wetlands in Alabama. The Nature Conservancy, along with the Coastal Land Trust, acquired 18,000 acres of wetlands in the Mobile-Tensaw River Delta. Most of this acreage has been sold to the Corps as part of its Tennessee-Tombigbee Waterway mitigation project and will be managed by the State. The Nature Conservancy has been instrumental in the purchase and preservation of several other wetland areas in the State, including the Bon Secour National Wildlife Refuge, the Weeks Bay National Estuarine Research Re- serve, several small (2- to 35-acre) pitcher plant bogs in northern Alabama, and a 156-acre tract in southern Alabama that is primar- ily pine savannah containing some wetlands. The Nature Con- servancy also has been requested by the FWS to assist in the estab- lishment of the Grand Bay Savannah National Wildlife Refuge in southwestern Alabama and southern Mississippi. This proposed 13,000-acre refuge will have substantial wetland acreage (Stratton Bull, The Nature Conservancy of Alabama, written commun., 1993). References Cited Alabama Department of Economic and Community Affairs, 1991, Alabama Statewide Comprehensive Outdoor Recreation Plan: Montgomery, Alabama Department of Economic and Community Affairs, 146 p. and appendix. Alabama Department of Environmental Management, 1992, Water-quality report to Congress: Montgomery, Alabama Department of Environ- mental Management, 105 p. and appendix. Cahaba River Society, 1992, It's almost lily time!: Cahaba River Society newsletter, May/June 1992, 16 p. Chandler, R.V.. and Moore, J.D., 1987, Springs in Alabama: Alabama Geo- logical Survey Circular 134, 95 p. Cowardin, L.M., Carter, Virginia, Golet, EC., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Dahl, T.E., 1990, Wetlands Losses in the United States, 1780's to 1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 13 p. Dahl, T.E., Johnson, C.E., and Frayer, W.E., 1991, Status and trends of wetlands in the conterminous United States, mid-1970's to mid-1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 28 p. Dardeau, M.R., Shipp, R.L. and Wallace, R.K., 1990, Faunal components, in Mobile Bay Issues, resources, status, and management Proceed- ings of a seminar held November 17, 1988: Washington, D.C., National Oceanic and Atmospheric Administration, Estuary-of-the-Month Seminar Series no. 15, p. 89-114. Duke, Thomas, and Kruczynski, W.L., eds., 1992, Status and trends of emergent and submerged vegetated habitats. Gulf of Mexico, USA: The Environmental Protection Agency, Gulf of Mexico Program, 161 p. Fenneman, N.M., 1946, Physical divisions of the United States: Washing- ton, D.C., U.S. Geological Survey special map, scale 1:7,000,000. Field, D.W., Reyer, A.J., Genovese, P.V., and Shearer, B.D., 1991, Coastal wetlands of the United States An accounting of a valuable national resource: Washington, D.C., National Oceanic and Atmospheric Ad- ministration and U.S. Fish and Wildlife Service cooperative report, 59 p. Hofstetter, R.H., 1983, Wetlands of the United States, in Gore, A.J.P., ed., Ecosystems of the world; 4B, Mires-Swamp, bog, fen and moor: Re- gional studies, Amsterdam, Elsevier Scientific Publishing Co., p. 201- 244. Jeffcoat, H.H., and Mooty. W.S., 1986, Alabama surface-water resources. in U.S. Geological Survey, National water summary 1985 Hydro- logic events and surface-water resources: U.S. Geological Survey Water-Supply Paper 2300, p. 131-136. Mitsch, W.J., and Gosselink, J.G., 1986, Wetlands: New York, Van Nostrand Reinhold Company, 537 p. Mohlenbrock, R.H., 1992, Conecuh bogs, Alabama: Natural History, v. 101, no. 3. p. 60-62. Rathburn, C.E., Watzin, M.C., Johnston, J.B., and O'Neil, P.E., 1987, Areal extent of wetlands above and below the 10-foot contour line in Ala- bama: U.S. Fish and Wildlife Service, National Wetland Research Center Open-File Report 86-3, 9 p. Roach, E.R., Watzin, M.C., Scurry, J.D., and Johnston, J.B., 1987, Wetland changes in coastal Alabama, in Lowery, T.A., ed., Proceedings of Symposium on the Natural Resources of the Mobile Bay Estuary, Mobile, Ala., February 10-12, 1987: Mobile, Ala., Auburn Univer- sity, Alabama Sea Grant Extension Service and Alabama Cooperative Extension Service, p. 92-101. Shaw, S.P., and Fredine, C.G., 1956, Wetlands of the United States Their extent and their value to waterfowl and other wildlife: U.S. Fish and Wildlife Service Circular 39. 67 p. Stout, J.P., 1979, Marshes of the Mobile Estuary Status and evaluation, in Loyacano, H.A., Jr., and Smith, J.P., eds., Proceedings of the Sym- posium on the Natural Resources of the Mobile Bay Estuary, Mobile, Ala., 1979: Mobile, Ala., U.S. Army Corps of Engineers, Mobile Dis- trict, p. 113-122. ____1990, Estuarine habitats, in Mobile Ba> Issues, resources, status, and management Proceedings of a seminar held in Washington, D.C., November 17, 1988: National Oceanic and Atmospheric Administra- tion, Estuary-of-the-Month Seminar Series no. 15, p. 63-88. U.S. Army Corps of Engineers, 1981, Environmental data inventory, State of Alabama: Mobile, Ala., U.S. Army Corps of Engineers, 325 p. U.S. Department of Agriculture, 1985, Status and conditions of land and water resources in Alabama, 1982: Auburn, Ala., U.S. Department of Agriculture, 140 p. U.S. Fish and Wildlife Service, 1992, Regional wetlands concept plan, Emergency Wetlands Resources Act, Southeast Region: Atlanta, U.S. Fish and Wildlife Service, 259 p. Watzin, M.C., Tucker, Sandy, and South, Celeste, in press, Environmental problems in the Mobile Bay ecosystem The cumulative effects of human activities: Mobile, Ala., Mississippi-Alabama Sea Grant Con- sortium Publication. Winter, T.C., and Woo, Ming-Ko, 1990, Hydrology of lakes and wetlands, in Wolman, M.G., and Riggs, H.C., eds., Surface water hydrology: Boulder, Colo., Geological Society of America, The Geology of North America, v. O-l, p. 159-187. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Survey, 520 19th Avenue, Tuscaloosa, AL 35401; Regional Wetland Coor- dinator, U.S. Fish and Wildlife Service, 1875 Century Building, Atlanta, GA 30345 Prepared by Benjamin F. McPherson, U.S. Geological Survey U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources 107 Alaska Wetland Resources laska has more area covered by wetlands approximately 170 million of its 367 million acres than the total area of wetlands in the other 49 States combined (Dahl, 1990). Alaska has a wide vari- ety of topographic, geologic, climatic, and hydrologic conditions that contribute to the variety of wetland complexes in the State. Alaska's wetland complexes differ in size, function, and type, and they in- clude types that are rare in other States, such as vast expanses of treeless tundra (fig. I) in northern Alaska and extensive black spruce peatlands, or muskegs, elsewhere in the State. Wetlands are sociologically, ecologically, and economically important to Alaska. Wetlands provide the resources for people in rural Alaskan villages to survive (Ellanna and Wheeler, 1990) almost all subsistence hunting, fishing, trapping, and food gather- ing occurs on or adjacent to wetlands. Many mammals, fish, and birds within the State depend on some type of wetland for breed- ing, nesting, rearing young, or feeding. Alaska's wetlands provide recreational opportunities and support related businesses for people who hunt, observe, and photograph wildlife. Alaska has seven wetland complexes that are important for their water-habitat value (Tiner, 1984): Yukon-Kuskokwim Delta, Izembek Lagoon, Yukon Flats, Teshekpuk Lake, upper Alaska Pen- insula, Copper River Delta, and upper Cook Inlet. In general, wet- lands in Alaska that have the highest value for waterfowl are coastal salt marshes and wetlands in and adjacent to lakes that have exten- sive periods of drawdown or that fluctuate with river flow (Lensink andDerksen, 1990). During spring and fall migrations, huge flocks of waterfowl (ducks, geese, and swans) and shorebirds (dowitchers, godwits, plovers, turnstones, sandpipers, curlews, snipe, phalaropes, and yellowlegs) stop at wetland areas in Alaska. More than 70,000 swans, 1 million geese, 12 million ducks, and 100 million shorebirds de- pend on Alaskan wetlands for resting, feeding, or nesting (King and Lensink, 1971). During years of drought in prairie States and Prov- inces of Canada, birds displaced from their traditional breeding areas fly northward to wetlands in Alaska. Alaska wetlands provide forage for large mammals such as caribou, moose, and musk oxen. They also provide food and habi- tat for beaver, muskrat, mink, and land otter. Rocky coastal beaches serve as rookeries (areas where breeding and pupping occur) and resting areas for marine mammals such as seal, sea lion, and wal- rus. Alaska wetlands sustain some of the world's richest commer- cial, sport, and subsistence fisheries. Almost 90 percent of wild salmon caught in the United States are caught in Alaskan waters. These fish rely on palustrine and riverine wetlands to provide food, cover, and spawning areas during their life in inland waters, and they pass through riverine, estuarine, and marine wetlands on their mi- gration to and from the ocean. Resident freshwater and estuarine fish also depend on wetland habitat. Wetlands in Alaska have important hydrologic and water-qual- ity functions, including flow regulation, erosion control, sediment retention, nutrient uptake, and contaminant removal. Many wetlands have limited flood-control or water-storage functions during snow- melt because their soils are seasonally or perennially frozen, limit- ing absorption of runoff. However, several characteristics of wet- lands help reduce peak flows, even when soils are frozen (Post, 1990). Water is detained behind hummocks and within depressions, ponds, and lakes, and the velocity of the water is slowed by vegeta- tion. The mosses, peats, and mineral soils of wetlands can become dryer during winter, and during snowmelt these materials are able to absorb some meltwater. Following snowmelt, wetlands have a greater capacity for streamflow regulation because the capacity of the soils to store water increases: higher temperatures increase the thickness of unfrozen soils and increase evaporation and plant tran- spiration, which help lower the water table. Wetland plants help control the erosion of mineral soils by decreasing wind and water velocities near the ground and by hold- ing soil particles together with their roots. In permafrost areas, veg- etation also reduces erosion by preventing the warming and thaw- ing of ice-rich soils. In flood plains, wetland vegetation removes some suspended sediment from floodwaters by slowing water ve- locities. Wetlands in Alaska transform and retain nutrients and toxic compounds. Nutrients and contaminants attach to the organic and fine mineral soils. Plants, phytoplankton, fungi, and bacteria use the nutrients and degrade some of the contaminants. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deepwater habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and others, 1979). The distribution of wetlands and deepwater habitats in Alaska is shown in figure 2A\ only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this sum- mary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Esluarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Alaska are described on page 3. Figure 1. Tundra on the Arctic coastal plain southwest of the Kavik River. Willow thickets are present along the meandering stream. (Photograph by F.C. Golet, U.S. Fish and Wildlife Service.) 108 National Water Summary Wetland Resources: STATE SUMMARIES !60' BFAUFORT SEA WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown Uttffum Suckling Sound Cape Fairweattier Predominantly wetland Predominantly deepwater habitat Glacier , ^35" vK I QJpredc ^* f ^^i j~:t,^.i,*r i<ic> 6°r\ is- 1 1 1 ^* «* i I 1 >*« . *j ^'eutt'an j island 5 \ ^^-" ~~~"^'^--J?° 175-- 170'- 1( 5" t ^ - * . Figure 2. Wetland distribution in Alaska and physical and climatological features that control wetland distribution in the State. A, Distribu- tion of wetlands and deepwater habitats, B, Geographic divisions. C, Climatic zones. (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 1991. B, Geographic divisions modified from Lamke, 1986; landforms data from EROS Data Center. C, Hartman and Johnson, 1978.) National Water Summary Wetland Resources: ALASKA 109 System Palustrine, Lacustrine Riverine. Estuarine. Wetland description Nontidal and tidal-freshwater wetlands in which vegetation is predominantly trees {forested wet- lands); shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted herba- ceous plants (persistent- and nonpersistent- emergent wetlands); mosses and lichens (moss- lichen wetland); or submersed and (or) floating plants (aquatic beds). Also, intermittently to per- manently flooded open-water bodies of less than 20 acres in which water is less than 6.6 feet deep. Nontidal and tidal-freshwater wetlands within an intermittently to permanently flooded lake or reservoir larger than 20 acres and (or) deeper than 6.6 feet. Vegetation, when present, is pre- dominantly nonpersistent emergent plants (non- persistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds), or both. Nontidal and tidal-freshwater wetlands within a channel. Vegetation, when present, is same as in the Lacustrine System. Tidal wetlands in low-wave-energy environments where the salinity of the water is greater than 0.5 part per thousand {ppt} and is variable owing to evaporation and the mixing of seawater and freshwater. Tidal wetlands that are exposed to waves and cur- rents of the open ocean and to water having a salinity greater than 30 ppt. Wetlands and deepwater habitats in Alaska are being invento- ried by the FWS. As of December 1992, about 25 percent of the State had been mapped to determine acreage of the wetland types within the classification system of Cowardin and others (1979). Wetlands also have been inventoried in some of Alaska's urban areas by the U.S. Army Corps of Engineers (Corps). Maps showing wetland areas for parts of Anchorage, Fairbanks, Juneau, and the Kenai Peninsula are available. The Natural Resource Conservation Service and Alaska Department of Natural Resources Soil and Water Conser- vation Districts also have mapped wetlands in some parts of south- central and interior Alaska having agricultural and potentially agri- cultural lands. The FWS 170-million-acre estimate for wetland area in Alaska (Dahl, 1990) is based on soil surveys, land-cover maps, National Wetland Inventory maps, and preliminary results of sta- tistical surveys conducted by the National Wetland Inventory. Marine. The Joint Federal-State Land Use Planning Commission for Alaska (1973), Batten and Murray (1982), Lee and Hinckley (1982), Batten (1990), and Viereck and others (1992) describe Alaska's wetland vegetation. Many plants in Alaska grow well in a wide range of climate, soil, and water conditions. Some species dominate plant communities on both wet and dry soils, sometimes making it diffi- cult to differentiate Alaska wetlands from uplands solely on the basis of vascular-plant communities. Palustrine System. Most of Alaska's wetlands are palustrine. Palustrine wetlands in Alaska include both peatlands (wetlands that have organic soils) and nonpeatlands. Peatlands, also known as mires, occur throughout Alaska and cover an estimated 27 to 110 million acres (Northern Technical Services and EKONO, Inc., 1980; Dachnowski-Stokes, 1941), depending on the peatland definition and inventory techniques used. In general, a peatland is a moss-li- chen, emergent, scrub-shrub, or forested wetland containing more than 12 inches of a wet organic soil (peat) consisting of partly to well-decomposed plants. However, definitions of peatland differ in the thickness of peat required. Peat forms when the rate of plant production exceeds the rate of decomposition, usually under wa- ter-saturated conditions. Poor air circulation, low levels of oxygen, and cool ground water within the saturated soil inhibit the activity of soil bacteria and fungi, so dead plant material decomposes slowly. Some peatlands in Alaska are underlain by poorly permeable silt, clay, well-decomposed peat, or bedrock, which contribute to the water-holding capacity of those sites. Throughout Alaska, peat is commonly several feet thick in topographic depressions and in poorly drained lowlands. Bogs and fens are peatlands that generally have a water table near the surface and ground-cover vegetation that is predominantly mosses. Sedges, heath shrubs, and trees commonly grow above the moss layer. In Alaska, sphagnum and feather mosses commonly dominate the ground cover in flat peatlands having rain and snow as the predominant sources of water (bogs), whereas brown mosses, grasses, and sedges are more prevalent on low-gradient slopes hav- ing some internal drainage or ground-water inflow (fens). A moss- floored peatland containing black spruce trees found primarily on cold, wet, poorly drained soils is commonly referred to as muskeg. A muskeg can be either a bog or a fen, depending on the source of water. Bogs and fens underlain by permafrost are extensive in wet, low-relief areas near the Yukon and Kuskokwim Rivers in interior Alaska, where they cover about 9 million acres (Joint Federal- State D PRECIPITATION Line of equal annual precipitation- Interval, In inches, is variable PERMAFROST I 'I Generally underlain by continuous permafrost B Underlain by discontinuous permafrost I ] Underlain by isolated masses of permafrost ^B Generally free from permafrost Figure 2. Continued. D, Average annual precipitation. E, Permafrost distribution. (Sources: D, Lamke, 1986. E, Ferrians, 1965.) 110 National Water Summary Wetland Resources: STATE SUMMARIES Land Use Planning Commission for Alaska, 1973). In southeastern Alaska, where the terrain is mountainous, fens are more abundant than bogs. Bogs and fens in southeastern Alaska form at the edges of mountain slopes and on adjacent lowlands. There, the wetlands are not underlain by permafrost but are commonly underlain by bedrock at a shallow depth. Tundra, marshes, and meadows form in wet areas over min- eral or organic soils. Tundra is characterized by treeless terrain covered by mosses, lichens, grasses, sedges, and low shrubs (mostly emergent, moss-lichen, or scrub-shrub wetland). Permafrost com- monly is present at a shallow depth. Tundra occurs where summers are not warm enough for tree growth and is most extensive in north- ern Alaska and above treeline in mountains throughout the State. Three general types of tundra communities exist wet, moist, and alpine. The Joint Federal-State Land Use Planning Commission for Alaska (1973) estimated that wet tundra covers about 33 mil- lion acres, moist tundra about 66 million acres, and alpine tundra about 85 million acres. Most lowland tundra remains wet or moist throughout the short thawing season because it is underlain by per- mafrost. However, only a small part of alpine tundra in higher moun- tain regions is considered wetland. Freshwater marshes (emergent wetlands) are periodically in- undated by standing or slowly moving water. Marshes in Alaska contain sedges, rushes, marestail. and other aquatic plants. The vegetation shows a distinct zonation according to water depth and frequency of exposure. Marshes are distinguished from bogs and fens by the general absence of moss, heath-type shrubs, and peat. Marshes are common around the margins of lakes, ponds, and riv- ers, in wet depressions and oxbows, on flood plains, in deltas, and on gently sloping benches receiving water from steeper slopes above. Wet meadows (emergent wetlands) occupy seasonally flooded sites that dry out late in the growing season, although soils typically re- main saturated. Wet meadows are covered predominantly by her- baceous emergent plants, usually sedges, and are present on flood plains, lakeshores, and poorly drained lowlands throughout the State. Palustrine wetlands within braided stream channels are com- monly dominated by woody plants and perennial herbs. Willow and alder are the predominant plants in riparian scrub-shrub wetlands adjacent to Alaska's many rivers. Cottonwood predominates in ri- parian forested wetlands. Ponds commonly contain aquatic beds with water lilies, pondweeds, and submersed aquatic plants. Lacustrine System. Alaska has hundreds of thousands of lakes which together cover more than 5 million acres (Joint Fed- eral-State Land Use Planning Commission for Alaska, 1973), but estimates of the area covered by wetlands within these lakes are not available. Lakes are abundant in lowlands underlain by permafrost, in oxbows along braided and meandering rivers, in depressions in glacial-drift deposits, and in mountain valleys dammed by glacial moraines. Many lakes in Alaska contain aquatic beds in deeper water and emergent aquatic plants in shallower water, commonly grading into surrounding palustrine and riverine wetlands. Lacustrine wetlands used extensively by waterfowl are char- acteristically in lakes having gradually sloping shorelines and ex- tensive shallow areas; profuse growth of submersed aquatic plants; a border of palustrine wetlands vegetated by emergent plants such as sedges, cattails, and bulrush; an extensive band of grassland around the lake; an abundance of aquatic insects; and a lake bot- tom composed of mineral soil (Lensink and Derksen, 1990). Those characteristics are common in lakes that have long periods of gradu- ally receding water levels or that are connected to a river. In the Yukon Flats, such lakes have the highest density of nesting water- fowl in interior Alaska, and they support a breeding population of more than 1 million ducks. Riverine System. Wetlands within river channels include bars and flats of mud, sand, or gravel. Alaska has tens of thousands of rivers, streams, and creeks, but estimates of riverine wetland acre- age are not available. Riverine wetlands provide critical spawning and rearing habitat for resident fish and for fish that migrate from the ocean to spawn. Many riverine wetlands are subject to annual or periodic inundations caused by snowmelt, glacier melt, and sum- mer rainfall. Vegetated wetlands in low-gradient channels include submersed and floating aquatic plants and nonpersistent emergent plants such as buckbean, pendent grass, and cinquefoil. Vegetated wetlands in high-gradient mountain streams are dominated by sub- mersed aquatic mosses. Estuarine System. Estuarine wetlands cover about 2 million acres in Alaska (Hall, 1988). Nonvegetated estuarine wetlands in- clude flats, beaches, and rocky shores, which cover about 1.7 mil- lion acres and are most abundant (about 874,000 acres) in north- western and southwestern Alaska. Tidal flats are mud and sand shores that appear to lack vegetation; however, a rich layer of mi- croscopic plants such as diatoms, blue-green algae, and dinoflagel- lates typically covers the sediments. Intertidal sand and mud flats bordering the Yukon-Kuskokwim Delta cover about 130,000 acres and in places are more than 6 miles wide. A series of barrier islands protects large areas of nonvegetated tidal flats in the Copper River Delta. More than 20,000 acres of tidal flats occur on the seaward edge of the Colville River Delta on the Beaufort Sea Coast. Exten- sive tidal flats not associated with major river deltas include Gustavus Flats near the mouth of Glacier Bay, intertidal lagoons of Tugidak and Sitkinak Islands south of Kodiak Island, and vast mudflats in upper Cook Inlet. Vegetated estuarine wetlands cover about 345,000 acres in Alaska (Hall. 1988). The most common type of estuarine vegetated wetland is the salt marsh (emergent wetland). Salt marshes contain- ing sedges and grasses occur in tidally flooded, low-energy areas, such as gently sloping shores close to the mouths of rivers or be- hind barrier islands and beaches. Large salt-marsh complexes oc- cur along the 500-mile shoreline of the Yukon-Kuskokwim Delta (about 162.000 acres), on the outer edge of the Copper River Delta, and in the upper Cook Inlet area. Several million migrating shore- birds and waterfowl use these coastal salt marshes for feeding and resting. Vegetated estuarine wetlands also include aquatic beds of al- gae and eelgrass. Rocky materials in tidal flats along the Aleutian Islands, in the western Gulf of Alaska, and in southeastern Alaska provide habitat for algae. During fall, nearly the entire world's popu- lation of Steller's eiders and emperor geese gather in aquatic-bed wetlands in lagoons along the upper Alaska Peninsula. Izembek Lagoon near the tip of the Alaska Peninsula contains one of the largest eelgrass beds in the world, more than 84,000 acres. This lagoon serves as an international crossroad for migratory waterfowl and shorebirds from Asia, the mid-Pacific, and North America. Safety Lagoon on Seward Peninsula and Tugidak Lagoon on Tugidak Island are other large eelgrass beds important to migrating water- fowl. Marine System. Marine wetlands, which border the open ocean and are exposed to high-energy waves, cover about 46,000 acres in Alaska (Hall. 1988). Nonvegetated marine wetlands are generally sand and cobble-gravel shores or rocky shores. Most of the 250-mile coastline between Cape Suckling and Cape Fair- weather in the northern part of the Gulf of Alaska is sand beach, whereas most of the coast along the Aleutian Island chain is bed- rock and boulder rocky shores. Vegetated marine wetlands occur primarily as algal aquatic beds colonizing rocky shores of the Alaska Peninsula and shores adjacent to the Gulf of Alaska. HYDROLOGIC SETTING Wetlands are present wherever topographic, climatic, and hy- drologic conditions favor the retention of water. Low relief, perma- frost, a general abundance of precipitation relative to evaporation National Water Summary Wetland Resources: ALASKA 111 and plant transpiration, short cool summers, poorly permeable rocks near the land surface, and large tidal fluctuations help form and maintain extensive wetlands in Alaska. Wetland characteristics con- tinuously change with changes in climate, water supply, soil mois- ture, salinity, maturation of vegetation communities, tectonic activ- ity, fire, ice scour, glacier advance and retreat, and human activi- ties such as draining and filling. Alaska has seven broad, generally recognized geographic re- gions (fig. 26), These regions are Southeast, Aleutian Islands, South- central, Southwest, Northwest, Arctic, and Interior Alaska. Alaska has four climatic zones Maritime, Transition, Continental, and Arctic (fig. 2C). The State's high mountain ranges, extensive coast- line, vast size one-sixth the total area of the United States and long north-to-south distance are the principal causes for the great differences in climate. From the northern part of the Arctic Zone to the southern part of the Maritime Zone, average annual precipita- tion ranges from about 5 to 320 inches (fig. 2D), and average an- nual temperature ranges from 10 to 45 degrees Fahrenheit. Two- thirds of the annual precipitation occurs from September through March in the Maritime Zone and from June through November in the Continental and Arctic Zones. In the Transition Zone, seasonal precipitation patterns are not sharply defined, fluctuate from year to year, and can resemble those of either the Maritime or Continen- tal Zones. Spring snowmelt supplies the most input to the annual water budget in most Alaskan wetlands. Snowmelt is generally confined to a short time period during spring but produces considerable run- off because it can represent the precipitation accumulated for most of the year. During summer, local rain or the melting of snow and glacier ice in upland areas replenishes the water supply of many wetlands. In much of the Southeast and South-central regions of Alaska, precipitation greatly exceeds evaporation. Many wetlands throughout Alaska are underlain by poorly permeable materials, such as decomposed peat, bedrock, silt, clay, seasonally frozen soils, or permafrost, that do not readily allow water from snowmelt or rain to pass through. Permafrost, soil having a temperature below freezing for 2 years or more, helps form and maintain wetlands in the Northwest, Arctic, and Interior regions. The extent and thickness of the permafrost decrease southward from a continuous layer as much as several hundred feet thick in the Arctic region to areas generally free of permafrost in the South-central and Southeast regions (fig. 2E). In the Arctic coastal plain, thawed soils in the summer commonly are no more than about 3-feet thick, lim- iting the rooting depth of plants and the infiltration of water. Long winters, cool summers, and the presence of permafrost maintain vast wet expanses under the same precipitation conditions that would produce only deserts in regions having temperate climates. Alaska has about 34,000 miles of shoreline. Extremely large tidal fluctuations occur daily in southeastern Alaska, Prince Will- iam Sound, Cook Inlet, and Bristol Bay, forming expansive tidal flats and salt marshes. The diurnal fluctuation during spring tides is about 40 feet vertically in upper Cook Inlet near Anchorage. In coastal areas having little topographic relief, such as those in the Southwest, Northwest, and Arctic regions, storm surges push seawater inland several miles and affect the types and growth of plants. Alaska's large rivers form extensive deltas. The Yukon-Kusko- kwim Delta is one of the world's largest and supports more than 10 million acres of wetland. The deltas of the Colville, Copper, and Stikine Rivers also support vast wetlands. Expansive wetlands, such as the Yukon, Minto, Kanuti, and Koyukuk Flats, also occur adja- cent to rivers flowing through large areas of low relief. Tectonic activities affect the hydrology of Alaska's wetlands. During the 1964 earthquake, the Copper River Delta was uplifted 6 to 13 feet, and the Portage area, which is 40 miles southeast of Anchorage, subsided as much as 8 feet. In the Copper River Delta, some wetlands that were salt marshes before the earthquake have become freshwater systems. Also, in some areas, salt marshes have migrated seaward almost a mile. Kodiak Island and parts of south- eastern Alaska are rising because glaciers whose weight had for- merly caused land subsidence are melting. The relative fall in sea level is presumably modifying wetlands above the tidal zone and creating wetlands within the new tidal zone. The productivity of many Alaska wetlands is affected by fires. Fires occur only infrequently in coastal areas, allowing as much as several tens of feet of peat to accumulate in some bogs and fens in southeastern Alaska. Fires, common in interior Alaska, rid marshes of dead grass, sedges, and shrubs and make new shoots available for waterfowl and mammals. Burning of vegetation and peat releases minerals and nutrients from organic litter, usually potassium, cal- cium, phosphorus, magnesium, chloride, and nitrogen. However, where permafrost is present, a severe fire may cause the relative abundance of plant species to change, especially if the fire removes the insulating organic layer, which in turn causes the top of the permafrost to lower. If the burned area remains undisturbed, wet- land conditions will eventually return, but it can take 50 to 100 years to complete the cycle. Sea ice and glaciers also affect Alaska wetlands. Sea ice scours the coast and limits the establishment of vegetation in intertidal and subtidal areas of the Bering, Chukchi, and Beaufort Seas. Advanc- ing glaciers can cover wetlands, whereas retreating glaciers provide new areas where wetlands can form. TRENDS Information on historical wetland gains and losses in Alaska is limited. Estimates of wetland losses for the entire State range from about 80,000 to 200,000 acres, or about 0.05 to 0.15 percent of the historic wetland area (Senner, 1989; Dahl, 1990). Senner (1989), using existing quantitative data and aerial photographic interpreta- tion techniques, estimated the following wetland losses through 1986 by activity: petroleum-related development, about 30,000 acres; mining, about 13,000 acres; infrastructure (roads, harbors, airports, and railroads), about 13,000 acres; development (residential, rec- reational, and commercial), about 13,000 acres; agriculture, about 8,500 acres; construction of military facilities (mostly roads and airfields), about 2,400 acres; and timber, less than 2,000 acres. Wetland losses have generally occurred in urban areas (Anchorage, Juneau, Fairbanks), around villages and communities, and in large industrial developments such as oil fields, transportation corridors, and industrial sites. As much as 50 percent of the wetlands in low- lying areas of Anchorage have been filled since 1945 (Alaska De- partment of Natural Resources, 1992). Any additional industrial, commercial, and residential development within areas that are pre- dominantly wetland, such as in the Southwest, Northwest, and Arc- tic regions, might result in further draining or filling of wetlands. CONSERVATION Many government agencies and private organizations partici- pate in wetland conservation in Alaska. The most active agencies and organizations and some of their activities are listed in table 1. Federal wetland activities. Development activities in Alaska wetlands are regulated by several Federal statutory prohibitions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Harbors Act; the 1972 Clean Water Act and amendments; the 1985 Food Security Act; the 1990 Food, Agriculture, Conservation, and Trade Act; the 1986 Emergency Wetlands Resources Act; and the 1972 Coastal Zone Management Act. Section 10 of the Rivers and Harbors Act gives the Corps au- thority to regulate certain activities in navigable waters. Regulated activities include diking, deepening, filling, excavating, and plac- 112 National Water Summary Wetland Resources: STATE SUMMARIES Table 1 . Selected wetland-related activities of government pliance with Swampbuster provisions and assists farmers in the iden- agencies and private organizations in Alaska, 1993 tification of wetlands and in the development of wetland protection, [Source: Classification of activities is generalized from information provided restoration, or creation plans. by agencies and organizations. , agency or organization participates in The 1986 Emergency Wetlands Resources Act and the 1972 wetland-related activity; .., agency or organization does not participate in Coastal Zone Management Act and amendments encourage wetland wetland-related activity. MAN, management; REG, regulation; R&C, resto- ,, , ~ ,. .. m, r vw «.i j ration and creation; LAN, land acquisition; R&D, research and data collec- protection through funding incentives. The Emergency Wetland tion; D&l, delineation and inventory] Resources Act requires States to address wetland protection in their _____________________________________ Statewide Comprehensive Outdoor Recreation Plans to qualify for v Federal funding for State recreational land; the National Park Ser- Agency or organization_____________^ <^ <ff" y^ <ff" <^ vice (NPS) provides guidance to States in developing the wetland FEDERAL component of their plans. Coastal States that adopt coastal-zone Department of Agriculture management programs and plans approved by the National Oceanic Consolidated Farm Service Agency........................... ... ... ... ... ... and Atmospheric Administration are eligible for Federal funding and Forest Service................................................................. ... technical assistance through the Coastal Zone Management Act. Natural Resources Conservation Service ................ ... ... Many large tracts of lan(} in Alaska are managed by Federal Department of Commerce agencies including the Bureau of Land Management (about 90 to National Oceanic and ° ° , ° . , __ Atmospheric Administration ........................................ . . ... ... . ... 100 million acres), the FWS (16 wildlife refuges covering about 77 Department of Defense million acres), the NPS (parks and preserves covering about 50 mil- Army Corps of Engineers .............................................. Hon acres), the U.S. Forest Service (2 National Forests covering Military reservations ..................................................... ... ... ... about 24 million acres), and the U.S. Department of Defense (about Department of the Interior 2 im } Because wetlands in Alaska are widespread, al- Bureauof Land Management...................................... ... _ , ' . , . _, tl_ r . Bureau of Mines most a^ °^ tnese tracts contain some wetland. Thus, these agencies Fish and Wildlife Service .............................................. ... directly or indirectly manage, inventory, or collect data on wetlands. Geological Survey.......................................................... ... ... ... ... ... Many agencies are restoring and enhancing fish and wildlife habi- Minerals Management Service................................... ... ... ... ... ... tats in wetlands that they manage. Reclamation of old mining sites, National Biological Service ......................................... ... ... ... ... . ... riverbanks trampled by fishermen, or other disturbed areas can in- National Park Service ................................................... ... , . . ,| Al , . ... o "I Environmental Protection Agency..................................... . ... ... . . elude revegetation and wetland restoration. Some agencies also are NATIVE ALASKAN REGIONAL AND acquiring new lands containing wetlands. Governmental and non- VILLAGE CORPORATIONS................................................. ... ... ... governmental groups and individuals have input into the manage- STATE ment plans for these Federal tracts. Department of Environmental Conservation................ ... . ... ... ... ... Afar/ye Alaskan regional and village corporation wetland ac- !5^!!!S±lV±£r I : : : : : : Imnes.-^^^Cl^^^^im^- Department of Transportation and cated about 44 million acres to Native Alaskan regional and village Public Facilities................................................................... ... ... ... ... ... corporations. Much of this land contains wetlands. University of Alaska........................................................... ... ... ... ... State wetland activities. Development activities in Alaska SOME BOROUGH AND LOCAL GOVERNMENTS.......... ...... wetlands are regulated by several State agencies. If the wetland is D^Snlim^d IZAT 'ONS . . . in a coastal area' a section 404 permit application is submitted to The Nature Conservancy'III^IIIIII^I"..".".!"' "' ".'.. . the Corps and also to the Alaska Division of Governmental Coor- dination, which coordinates the review of permit applications by the Alaska Department of Environmental Conservation, Alaska Depart- ing of structures. The related section 404 of the Clean Water Act is ment of Fish and Game, and Alaska Department of Natural Re- the most often-used Federal legislation protecting wetlands. Under sources. The Division of Governmental Coordination also deter- section 404 provisions, the Corps issues permits regulating the dis- mines whether a proposed coastal activity is consistent with the charge of dredged or fill material into wetlands. Permits are sub- standards of the Alaska Coastal Management Program and with local ject to review and possible veto by the U.S. Environmental Protec- management policies and plans. State-agency reviews of permit tion Agency (EPA), and the FWS has review and advisory roles. Sec- applications for activities outside of coastal areas are not coordi- tion 401 of the Clean Water Act grants to States and eligible Indian nated by the Division. Tribes the authority to approve, apply conditions to, or deny sec- The Department of Environmental Conservation certifies per- tion 404 permit applications on the basis of a proposed activity's mit applications for compliance with State water-quality standards probable effects on the water quality of a wetland. under section 401 of the Clean Water Act and compliance with other Most farming, ranching, and silviculture activities are not sub- State laws and regulations. Pursuant to section 305(b) of the Clean ject to section 404 regulation. However, the "Swampbuster" provi- Water Act, the Department submits to the EPA and the U.S. Congress sion of the 1985 Food Security Act and amendments in the 1990 a biennial assessment of the State's water quality, including that in Food, Agriculture, Conservation, and Trade Act discourage (through wetlands (Alaska Department of Environmental Conservation, financial disincentives) the draining, filling, or other alteration of 1992). wetlands for agricultural use. The law allows exemptions from pen- Under Title 16 of the Alaska statutes, the Department of Fish allies in some cases, especially if the farmer agrees to restore the and Game has discretion to approve, deny, or issue conditional per- altered wetland or other wetlands that have been converted to agri- mits for activities affecting fish and wildlife and their habitats within cultural use. The Wetlands Reserve Program of the 1990 Food, State critical-habitat areas (about 1.4 million acres), game refuges Agriculture, Conservation, and Trade Act authorizes the Federal (about 1.3 million acres), and game sanctuaries (about 94,000 Government to purchase conservation easements from landowners acres), many of which contain wetlands. Outside of such areas, The who agree to protect or restore wetlands. The Consolidated Farm Department's role is limited to activities affecting anadromous-fish Service Agency (formerly the Agricultural Stabilization and Con- habitat. servation Service) administers the Swampbuster provisions and Wet- The Department of Natural Resources Division of Parks and lands Reserve Program. The Natural Resources Conservation Outdoor Recreation is the lead agency developing State Compre- Service (formerly the Soil Conservation Service) determines com- hensive Outdoor Recreation Plans for Alaska. Pursuant to the re- National Water Summary Wetland Resources: ALASKA 113 quirements of the Emergency Wetlands Resources Act of 1986, the plan (Alaska Department of Natural Resources, 1992) prioritizes wetland protection by wetland type and function and outlines cri- teria used for the selection of high-recreational-value wetlands for possible acquisition. The Department of Natural Resources Soil and Water Conservation Districts help private landowners determine whether the landowner's rural properties contain wetlands and whether a proposed activity requires permits from Federal and State agencies. As a result of the 1959 Alaska Statehood Act, Alaska gained selection rights to about 105 million acres from the Federal Gov- ernment. So far, the State has received title to about 85 million acres. The State also owns about 65 million acres of submersed lands that include the land between mean high tide and 3 miles offshore and the land under many large lakes and rivers. Most State lands are managed by the Department of Natural Resources, including about 3 million acres in State parks and about 2 million acres in State forests. The University of Alaska owns some wetlands and has sev- eral academic departments researching wetlands and fish and wild- life that use wetlands. Regional, borough, and local wetland activities. The Alaska Coastal Management Act established the Alaska Coastal Manage- ment Program, which is described by the Alaska Division of Gov- ernmental Coordination (1990, 1991) and Kyle (1982). The act al- lows local governments, rural regions, and the State to cooperatively protect and manage Alaska's coastal resources, including wetlands. The coastal zone includes all marine waters and submersed lands extending offshore to the 3-mile limit of State jurisdiction and in- land areas affecting coastal waters and resources. Many communi- ties are along the coast or along a major river within the coastal zone. Thirty-three coastal communities or regions have formed districts to work with the Alaska Coastal Policy Council and to prepare Coastal Management Plans that guide development in their local areas. These district plans influence local, State, and Federal deci- sions on development within the district, including the issuance of section 404 permits. Anchorage, Juneau, Homer, Kodiak, and Sitka have wetland- management plans designating critical wetlands where little or no development is allowed, as well as less valuable wetlands that may be available for development. These plans aid project planning, decrease the number of permit applications, and expedite review of approvable projects. General permits can be issued by the Corps to authorize speci- fied activities within an area, such as a coastal district. They can be administered by a local government and eliminate the need for in- dividual evaluation. Private wetland activities. Alaska has many private-interest groups that keep the public informed on wetland issues, organize citizen networks, and lobby either for or against wetland-protection measures. The Nature Conservancy helps government agencies and private landowners identify rare and important ecological commu- nities, protects valuable habitats and natural systems through ac- quisition or purchase, and assists governmental agencies and other conservation organizations in their land-preservation efforts. Ducks Unlimited has helped government agencies acquire, enhance, and protect wetlands used by waterfowl in the Anchorage, Fairbanks, and the Copper River Delta areas. The Alaska Center for the Envi- ronment, Anchorage Waterways Council, National Audubon Soci- ety, National Wildlife Federation, Sierra Club, Southeast Alaska Conservation Association, and Trustees for Alaska are a few of the organizations engaged in activities to protect Alaska's wetlands, in- cluding programs to educate the public about wetland issues. The Alaska Wetlands Coalition opposes potential developmental con- straints and is lobbying for the State to be exempt from portions of section 404 regulations because of the abundance of wetlands in the State. References Cited Alaska Department of Environmental Conservation, 1992, Alaska water quality assessment, 1992: Juneau, Alaska Department of Environmen- tal Conservation, Division of Environmental Quality, Water Quality Management Section, 57 p. Alaska Department of Natural Resources, 1992, Alaska's outdoor legacy Statewide Comprehensive Outdoor Recreation Plan, 1992-1996, Public review draft: Anchorage, Alaska Department of Natural Re- sources, Division of Parks and Outdoor Recreation, 100 p. Alaska Division of Governmental Coordination, 1990, Alaska coastal man- agement program Annual report, Fiscal year 1989: Juneau, Division of Governmental Coordination, 29 p. ____1991, Alaska coastal management program Statutes and regula- tions, September 1991: Juneau, Division of Governmental Coordina- tion, 105 p. Batten, A.R., 1990, A synopsis of Alaska wetland vegetation, in Alaska Regional wetland functions, Proceedings of a workshop, Anchorage, Alaska, May 28-29, 1986: University of Massachusetts at Amherst, The Environmental Institute Publication 90-1, p. 23-44. Batten, A.R., and Murray, D.F., 1982, A literature survey on the wetland vegetation of Alaska: U.S. Army Engineer Waterways Experiment Station Technical Report Y-82-2, 222 p. Cowardin, L.M., Carter, Virginia, Golet, EC., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Dachnowski-Stokes, A.P., 1941, Peat resources in Alaska: U.S. Department of Agriculture Technical Bulletin 769, 82 p. Dahl,T.E., 1990, Wetlands Losses in the United States, 1780'sto 1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 13 p. Ellanna, L.J., and Wheeler, P.C., 1990, Subsistence use of wetlands in Alaska, in Alaska Regional wetland functions, Proceedings of a workshop, Anchorage, Alaska, May 28 -29,1986: University of Mas- sachusetts at Amherst, The Environmental Institute Publication 90- 1, p. 85-103. Ferrians, O.J., Jr., 1965, Permafrost map of Alaska: U.S. Geological Sur- vey Miscellaneous Geologic Investigations Series Map 1-445, scale 1:2,500,000. Hall, J.V., 1988, Alaska coastal wetlands survey: Anchorage, U.S. Fish and Wildlife Service, 34 p. Hartman, C.W., and Johnson, P.R., 1978, Environmental atlas of Alaska: Fairbanks, University of Alaska, Institute of Water Resources, 101 p. Joint Federal - State Land Use Planning Commission for Alaska, 1973, Ma- jor ecosystems of Alaska: Washington, D.C., U.S. Geological Survey map, scale 1:2,500,000. King, J.G., and Lensink, C.J., 1971, An evaluation of Alaskan habitat for migratory birds: U.S. Department of the Interior, Bureau of Sport Fisheries and Wildlife Administrative Report, 74 p. Kyle, A.D., 1982, Local planning for wetlands management A manual for districts in the Alaska Coastal Management Program: Juneau, Alaska Office of Coastal Management, 89 p. Lamke, R.D., 1986, Alaska surface-water resources, in U.S. Geological Survey, National water summary 1985 Hydrologic events and sur- face-water resources: U.S. Geological Survey Water-Supply Paper 2300,p. 137-144. Lee, L.C., and Hinckley, T.M., 1982, Impact of water level changes on woody riparian and wetland communities The Alaska region: U.S. Fish and Wildlife Service Report FWS/OBS-82/22, v. IX, 212 p. Lensink, C.J., and Derksen, D.V., 1990, Evaluation of Alaska wetlands for waterfowl, in Alaska Regional wetland functions, Proceedings of a workshop, Anchorage, Alaska, May 28 -29,1986: University of Mas- sachusetts at Amherst, The Environmental Institute Publication 90- 1, p. 45-84. Northern Technical Services and EKONO, Inc., 1980, Peat resource esti- mation in Alaska: Anchorage, Northern Technical Services, v. 1,107 p. (contract report prepared for the U.S. Department of Energy). Post, R.A., 1990, Effects of petroleum operations in Alaskan wetlands A critique: Alaska Department of Fish and Game Technical Report 90- 3, 112 p. Senner, R.G.B., 1989, Effects of petroleum operations in Alaskan wetlands: Anchorage, Robert Senner and Company, 138 p. 114 National Water Summary Wetland Resources: STATE SUMMARIES Tiner, R.W., Jr., 1984, Wetlands of the United States Current status and recent trends: Washington, D.C., U.S. Fish and Wildlife Service, 59 p. Viereck, L.A., Dyrness, C.T., Batten, A.R., and Wenzlick, K.J., 1992, The Alaska vegetation classification: U.S. Forest Service, General Tech- nical Report PNW-GTR-286, 278 p. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Survey, 4230 University Drive, Suite 201, Anchorage, AK 99508; Regional Wetland Coordinator, U.S. Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, AK 99503 Prepared by Roy L. Glass, U.S. Geological Survey U.S. Geological Survey Water-Supply Paper 2425 Mational Water Summary Wetland Resources 115 Arizona Wetland Resources Less than 1 percent of Arizona's landscape has wetlands (Arizona State Parks, 1989). Since the late 1800's, streams and wetlands throughout Arizona have been drained or modified, resulting in the loss of more than one-third of the State's original wetlands (Dahl, 1990). Despite their limited extent, wetlands are a valuable resource for the State's people and wildlife. Benefits derived from the State's wetlands include flood con- trol, streambank stabilization, water-quality improvement, water supply, wildlife habitat, recreation, and education. Riparian wetlands can lessen the severity of floods by retaining stormwater and re- leasing it slowly. Riparian vegetation can stabilize streambanks and reduce erosion. Wetlands can improve water quality by decreasing the sediment and pollutant load in the water that filters through the wetland (Carter, 1986). Rivers, lakes, and artificial stock ponds are sources of water for public supply, irrigation, and livestock use. Wetlands are among the most valuable wildlife habitats in Ari- zona (Arizona State Parks, 1989). The variety and concentration of wildlife in wetlands are the result of abundant water, diverse veg- etation (which provides adequate cover), and the dynamic and tran- sitional nature of constantly changing water levels. Wetlands provide essential habitat for many waterfowl and other birds (including shorebirds and tropical migrants), amphibians, fish, and mammals. Some of the threatened or endangered species that depend directly or indirectly on Arizona wetlands include the bald eagle, humpback chub, Apache trout, Gila topminnow, Yuma clapper rail, Hualapai Mexican vole, and ocelot (Arizona State Parks, 1989). Recreational use of wetlands benefits the State economically. Arizona's streams and wetlands offer diverse recreational experi- ences, including boating, hunting and fishing, camping, hiking, and wildlife watching. During 1978, in more than 46,000 visits to just three wetlands in southern Arizona, nonresident wildlife watchers generated more than $5 million in tourist revenue, or approximately S 12,370 per acre (Arizona State Parks, 1989). Some wetlands, such as Montezuma Well (fig. I), also are of historical, archeological, and cultural interest and provide opportunities for education and re- search. Many Arizona tourist attractions are prehistoric and historic settlements that developed around streams and wetland areas that provided fish, game, and water. Figure 1. Montezuma Well, a lacustrine spring-fed wetland/deepwater habitat that has formed in a sink- hole. Located in a semiarid basin, this wetland was one of the few sources of water for prehistoric inhabitants of the area. (Photograph by Eleanor Robbins, U.S. Geological Survey.) TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deep- water habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and oth- ers, 1979). The distribution of wetlands and deepwater habitats in Arizona is shown in figure 2A; only wetlands are discussed here- in. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification systm, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other sytems comprise wetlands and deep- water habitats. Wetlands of the systems that occur in Arizona are described below. System Palustrine Lacustrine Riverine Wetland description Wetlands in which vegetation is predominantly trees (forested wetlands); shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted, herbaceous plants (persistent- and nonpersistent-emergent wetlands}; or sub- mersed and (or) floating plants (aquatic beds). Also, intermittently to permanently flooded open-water bodies of less than 20 acres in which water is less than 6.6 feet deep. Wetlands within an intermittently to permanently flooded lake or reservoir. Vegetation, when pres- ent, is predominantly nonpersistent emergent plants (nonpersistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds), or both. Wetlands within a channel. Vegetation, when pres- ent, is same as in the Lacustrine System. Palustrine wetlands are represented in Arizona by riparian wetlands that include oxbow lakes, marshes, cienegas, and bosques and nonriparian wetlands such as tinajas. Palustrine wetlands also include artificially created wetlands such as farm ponds and cattle stock ponds. Riparian wetlands are in a transitional zone between the stream or lake and the dry desert upland. These habitats, the most extensive Arizona wetland habitat type, form as a result of consis- tently wet surface or subsurface conditions. Oxbow lakes are former river channels that are sustained by floodwater from the nearby main stem of a river. Cienegas are riparian spring-fed marshes that are surrounded by upland and characterized by permanently saturated, organic soils (Arizona State Parks, 1989). Cottonwood and willow bosques (forests) are largely restricted to the flood plains of peren- nial and intermittent streams. The forests are sustained by winter and spring flooding. Some streams are sustained by ground-water pumpage and have provided a scattering of aquatic communities in arid parts of Arizona that were once devoid of surface water. Tinajas, also known as rock pools, are small depressions scoured in bedrock by boulders moved by flash floods (Arizona State Parks, 1988). Lacustrine wetlands in Arizona include playas and caldera lakes. Playas, also referred to as sinks or sinkholes, are dry, unvegetated lakebeds in closed basins. The surface water of playa 116 National Water Summary Wetland Resources: STATE SUMMARIES lakes comes from direct precipitation and runoff; over time, the surface water evaporates and leaves tightly compacted fine sedi- ments that compose the lake bottom. During wetter years, these areas can be flooded. Caldera lakes are formed by the collapse of basalt crust over a volcanic vent. Riverine wetlands in Arizona occur in perennial, ephemeral, and intermittent streams. Perennial streams contain flowing water throughout the entire year. Intermittent streams are streams that flow seasonally. Ephemeral streams, called washes, flow occasionally and only as a result of surface runoff from precipitation. HYDROLOGIC SETTING Extreme aridity and seasonally varying precipitation are the climatic characteristics that most significantly affect wetland for- mation and distribution in Arizona. The State's few perennial streams arise mainly at higher altitudes, where there is more moisture and lower evaporation rates. As these streams descend to the desert plains, evaporative losses and seepage to the ground-water system greatly reduce or eliminate surface flows. PHYSIOGRAPHIC DIVISIONS 25 50 MILES 0I r H ' 0 25 50 KILOMETERS WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown ^^^1 Predominantly wetland Predominantly deepwater habitat Figure 2. Wetland distribution in Arizona and physiography of the State. A, Distribution of wetlands and deepwater habitats. B, Physiogra- phy. (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 1991. B, Physiographic divisions from Brown, 1985; landforms data from EROS Data Center.) National Water Summary Wetland Resources: ARIZONA 117 Most wetlands in Arizona require more moisture than that pro- vided by local precipitation. Such moisture is available in drainages and their flood plains (riparian zones) (fig. 3), on poorly drained lands, and in and near other wet areas such as ponds, margins of lakes, and springs and their outflows. Arizona can be divided into six physiographically distinct re- gions for purposes of discussing wetland hydrology (fig. 26). These six regions are the (1) White Mountains, (2) the San Francisco Pla- teau, (3) Northern Arizona, (4) South-Central Arizona, (5) South- eastern Arizona, and (6) the Lower Colorado River. While Mountains. The White Mountains region is the wet- test part of the State; precipitation averages more than 23 inches per year, of which more than 50 percent falls as snow (Brown, 1985). Snow is the main source for most of Arizona's perennial streams. Most of the vegetated wetlands in the region are above 8,000 feet in the cold boreal or subalpine climatic zone (Arizona State Parks, 1989). Many of the wetlands have been flooded by reservoirs. The water in these reservoirs typically is clear and promotes abundant aquatic vegetation (Brown, 1985). Reservoir wetlands in the White Mountains region are the nesting habitat of more than 70 percent of the waterfowl present in Arizona (Brown, 1985). Playas are present east of Show Low, below 5,500 feel in altitude (Arizona State Parks, 1989). Riparian wetlands in the region are on flood plains of high-altitude creeks and other drainages. San Francisco Plateau. Annual precipitation in the San Francisco Plateau region averages about 19 inches, and about 75 percent falls as snow (Arizona State Parks, 1989). Because of a per- meable substrate of basalt and cinder, the San Francisco Plateau has few perennial streams. Most wetlands are in intermountain grass- lands or open woodlands and have a seasonal water regime that depends on winter precipitation and snowmelt. Palustrine emergent, scrub-shrub, and forested wetlands form around caldera lakes. Caldera lakes typically are found at altitudes between 6,900 and 7,200 feet (Arizona State Parks, 1989). An example is Mormon Lake, which is southeast of Flagstaff and is the State's largest natu- ral water body. Northern Arizona. The Northern Arizona region has a cold- temperate to boreal climate (Arizona State Parks, 1988). At least four types of palustrine wetlands exist in this region. These wetlands include small seasonal lakes in the southern part of the Northern Arizona region, tule-fringed sinkholes (emergent wetland), marshes of the Little Colorado River and a few of its tributaries, and ripar- ian forested wetlands (Brown, 1985; Platts and Jensen, 1986). PALUSTPINE WETLAND PALUSTRINE WETLAND m EXPLANATION Scrub-shrub vegetation Cotton wood-willow forest Emergent vegetation Mesqurte forest figure 3. Hydrologic setting of wetlands in riparian areas of the Sonoran Desert (Source; Arizona State Parks, 1988.) South-Central Arizona. The South-Central Arizona region has a warm-temperate to tropical-subtropical climate (Arizona State Parks, 1988). Most of the wetlands in this region have disappeared during the 20th century because of large-scale surface-water diver- sions and extensive ground-water pumping required to support municipal and agricultural development. Oxbow lakes and associ- ated marshes were once fairly common in the flood plains of the major rivers in this area, particularly along the lower Verde, Salt, and Gila Rivers. Most of the wetlands in this part of the State are directly associated with the free-flowing, unmodified stream seg- ments in the more mountainous regions and with ephemeral and intermittent streams at lower altitudes. Forested wetlands are com- mon in this region. Southeastern Arizona. Summer precipitation in Southeast- ern Arizona is more predictable than in other parts of the State and generally exceeds winter precipitation. Historical accounts of this area describe many extensive ponds and shallow grassy marshes (Arizona State Parks, 1989). Channelization and ground-water with- drawals have drained most of the marshes, and those that remain have been stripped of vegetation and reduced in size. Seasonal playa lakes are common in this region. A few cienegas and other marshes exist in the northern part of the region, but similar wetlands have disappeared or have been eliminated in the eastern part of the re- gion (Arizona State Parks, 1989). Many of the cienegas and marshes are directly connected to linear riparian corridors associated with streams. Wetlands in the region occur at altitudes between 3,200 and 4,600 feet (Arizona State Parks, 1989). Lower Colorado River. The Lower Colorado River region has a tropical-subtropical climate (Arizona State Parks, 1988). In the extreme northwestern part of the region, wetlands are directly as- sociated with the Colorado River and the Virgin River. Historically, oxbow lakes and associated marshes were common in this area. Construction of Hoover Dam in 1935, however, eliminated the natu- ral fluctuations of the Colorado River, which deprived many oxbow lakes of their major source of water. The result has been a decrease in wetlands associated with oxbow lakes. TRENDS Arizona's landscape was not always as dry as it is today. Little more than a century ago, Arizona had a natural river-drainage sys- tem that flowed year-round and spanned nearly every part of the State (Arizona State Parks, 1989). Perennial streams sustained the Native American and Hispanic cultures that occupied the State and provided water for a fledgling Anglo- American pioneer community. Arizona has lost many of its natural wetlands as the increasing requirements of agriculture, mining and other industry, and cities have resulted in the modification of the State's aquatic landscape. All the major rivers and many of the lesser streams have been impounded, regulated, and diverted (Arizona State Parks, 1989). Many other perennial streams and wetlands have disappeared because ground-water pumping has drained the aquifers, and other land-use practices have altered the hydrology of the drainage basins. Some of these changes were implemented for flood control, water storage, and hy- droelectric power. Others changes resulted from land- use practices and water-management actions (Arizona State Parks, 1989). Regardless of the causes, the re- structuring of Arizona's stream and wetland systems has affected the natural extent and distribution of these resources. The result has been greatly diminished op- portunities for stream- and wetland-based recreation and degraded open-space quality in and around urban communities. Further, diminished natural-runoff re- 118 National Water Summary Wetland Resources: STATE SUMMARIES Table 1 . Selected wetland-related activities of government agencies and private organizations in Arizona, 1993 [Source: Classification of activities is generalized from information provided by agencies and organizations. , agency or organization participates in wetland-related activity;..., agency or organization does not participate in wetland-related activity. MAN, management; REG, regulation; R&C, res- toration and creation; LAN, land acquisition; R&D, research and data col- lection; D&l, delineation and inventory] Agency or organization tention caused by wetland alteration or destruction has led to faster rising streams and higher flood peaks; these conditions have elimi- nated native fish and wildlife species in some areas. Dahl (1990) estimates that, from predevelopment times until the 1980's, wetland acreage in Arizona decreased by more than one- third. Harvesting of trees for fuel and building supplies, overgraz- ing, conversion to croplands, inundation by impoundments, desic- cation caused by diversions, invasion of nonnative plant species, plant eradication for increased water yield and flood control, flood- plain development for urban needs, sand and gravel mining, and channelization and flood control have directly affected riparian FEDERAL wetlands. Losses of nonflowing surface water and aquatic habitat Department of Agriculture in cienegas also have been extensive. Consolidated Farm Service Agency........................... ... . Trends that will affect the future of wetlands in Arizona are the Forest Service ................................................................. ........ increasing population and urbanization; the changing attitudes about Natural Res rces Conservation Service ................ . . . . ,, f j - - ^ j- -f Department of Defense land-, water-, and riparian-resource uses; the diversifying economy; Army Corps of Engineers .............................................. ... and the shifting and increasingly complex patterns of water use. The Military reservations population and urbanization trends can be expected to affect stream Department of the Interior and wetland resources because the demand for wetland recreation Bureau of Land Management...................................... . .... will continue to increase, and municipal development will increase Bureau of Reclamation ................................................. . . pressure to encroach on riparian areas for residential, commercial, 's . a B-'J ^ ^rvice.............................................. . and industrial activities. GeV^gical'sur^ey.......J..!.IIIIIIIII" .. .. ... I .. National Park Service ................................................... ........ y-x-vik icrr>« /A-i-n-\fc. i Environmental Protection Agency.................................. . . CONatKVAl I(JN TRIBAL Many government agencies and private organizations partici- j^TeElndian tnbes ------------- pate in wetland conservation in Arizona. The most active agencies Department of Environmental Quality ........................... ... and organizations and some of their activities are listed in table 1. Department of Water Resources.................................... ... . ... .. . Federal wetland activities. Development activities in Ari- Game and Fish Department.............................................. ...... zona wetlands are regulated by several Federal statutory prohibi- Outdoor Coordinating Commission............................. tions and incentives that are intended to slow wetland losses. Some State parks.............................................................. . . . . ft, . c , . j i. ,o r>- j COUNTY AND LOCAL of the more important of these are contained in the 1899 Rivers and Counties ... Harbors Act; the 1972 Clean Water Act and amendments; the 1985 Municipalities ..................................................................... . . Food Security Act; the 1990 Food, Agriculture, Conservation, and Salt River Project................................................................ . Trade Act; and the 1986 Emergency Wetlands Resources Act. PRIVATE ORGANIZATIONS Section 10 of the Rivers and Harbors Act gives the U.S. Army Desert Fishes Council - - - ^ fi- /-/-> \ ..i -^ *. i *. .. * ,.- Ducks Unlimited....................................................... Corps of Engineers (Corps) authority to regulate certain activities Johnson Historjca| Museum of the Southwest in navigable waters. Regulated activities include diking, deepening. National Audubon Society filling, excavating, and placing of structures. The related section 404 Arizona Riparian Council.................................................. . . of the Clean Water Act is the most often-used Federal legislation Arizona Wildlife Federation ........... protecting wetlands. Under section 404 provisions, the Corps issues The Arizona Nature Conservancy .................................. ... permits regulating the discharge of dredged or fill material into itte rust....................................................................... . . _ wetlands. Permits are subject to review and possible veto by the U.S. Environmental Protection Agency, and the FWS has review and ad- visory roles. Section 401 of the Clean Water Act grants to States tification of wetlands and in the development of wetland protection, and eligible Indian Tribes the authority to approve, apply conditions restoration, or creation plans. to, or deny section 404 permit applications on the basis of a pro- The 1986 Emergency Wetlands Resources Act encourages posed activity's probable effects on the water quality of a wetland. wetland protection through funding incentives. The act requires Most farming, ranching, and silviculture activities are not sub- States to address wetland protection in their Statewide Comprehen- ject to section 404 regulation. However, the "Swampbuster" provi- sive Outdoor Recreation Plans to qualify for Federal funding for sion of the 1985 Food Security Act and amendments in the 1990 State recreational land; the National Park Service provides guidance Food, Agriculture, Conservation, and Trade Act discourage (through to States in developing the wetland component of their plans, financial disincentives) the draining, filling, or other alteration of State wetland activities. The Arizona Game and Fish Depart- wetlands for agricultural use. The law allows exemptions from pen- ment is responsible for the management of fish and wildlife through- allies in some cases, especially if the farmer agrees to restore the out the State except within Indian reservations (Arizona State Parks, altered wetland or other wetlands that have been converted to agri- 1989). The Department of Environmental Quality is responsible for cultural use. The Wetlands Reserve Program of the 1990 Food, setting, monitoring, and enforcing water-quality standards for all Agriculture, Conservation, and Trade Act authorizes the Federal navigable waters, their major tributaries, and all ground water of the Government to purchase conservation easements from landowners State. The Department of Water Resources has authority for gen- who agree to protect or restore wetlands. The Consolidated Farm eral control and supervision of the waters in Arizona and the ap- Service Agency (formerly the Agricultural Stabilization and Con- propriation and distribution of such waters, servation Service) administers the Swampbuster provisions and Through the actions of the Game and Fish Department, De- Wetlands Reserve Program. The Natural Resources Conservation partment of Environmental Quality, Department of Water Resources. Service (formerly the Soil Conservation Service) determines com- and State Parks, the State has taken steps to conserve streams and pliance with Swampbuster provisions and assists farmers in the iden- wetlands and promote their recreational use but has not established National Water Summary Wetland Resources: ARIZONA 119 a comprehensive policy pertaining to these resources. The Ripar- ian Area Advisory Committee, made up of agencies, associations, citizen groups, and academia, currently (1993) is working on a full report to the Governor that will address a statewide policy and rec- ommendations. County and local wetland activities. The framework exists within county and city governments to incorporate wetland areas as assets to the local community. Local governments can establish policies to protect wetlands by restricting nearby development and land uses. Arizona municipalities that have programs or policies to facilitate the protection of wetlands and riparian areas include Scottsdale, Prescott, Tucson. Sierra Vista, Show Low. and Pinetop. The quasi-public Salt River Project's activities have major im- plications for streams and wetlands in Arizona (Arizona State Parks, 1989). The reservoirs and irrigation projects that the Project ad- ministers have inundated or otherwise drastically altered tens of thousands of acres of native riparian areas and hundreds of miles of free-flowing streams (Arizona State Parks, 1989). In recent years, however, the Project has been active in the Arizona Riparian Coun- cil and in work to establish methods of measuring and permitting critical instream flows. Additionally, the Project's environmental policy includes protection of aquatic ecology and cooperation with Federal, State, and local agencies responsible for environmental pro- tection. Private wetland activities. Programs from private groups focus mainly on the acquisition and management of stream and ri- parian areas, education and information exchange, wetland resto- ration, and advocacy for wetland recreation and conservation. The Nature Conservancy, an international nonprofit organization, seeks to protect rare plants and animals by preserving the habitats they need to survive critical lands in the United States and beyond our borders. The Arizona Riparian Council provides an important com- munication channel for professionals working in the area of ripar- ian-habitat management. Through the work of its subcommittees, the Council has begun to address coordination and consistency problems within the existing decentralized statewide riparian-man- agement system. References Cited Arizona State Parks, 1988, Chapter 3 Wetlands resources in Arizona An addendum to 1983 statewide comprehensive outdoor recreation plan: Phoenix, Arizona State Parks, p. 29-60. ____1989, Arizona rivers, streams, and wetlands study, in 1989 State- wide comprehensive outdoor recreation plan: Phoenix, Arizona State Parks, 244 p. Brown, D.E., 1985, Arizona wetlands and waterfowl: Tucson, University of Arizona Press, 169 p. Carter, Virginia, 1986, An overview of the hydrologic concerns related to wetlands in the United States: Canadian Journal of Botany, v. 64, p. 364-374. Cowardin, L.M., Carter, Virginia, Golet, EC., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Dahl, T.E., 1990, Wetlands Losses in the United States, 1780's to 1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 13 p. Platts, W.S., and Jensen, Sherman, 1986, Wetland/riparian ecosystems of the Great Basin/desert and montane region An overview, in Great Basin/Desert and Montane Regional Wetland Functions Proceed- ings of a workshop held at Logan, Utah, February 27-28, 1986: The Environmental Institute, University of Massachusetts at Amherst Pub- lication 90-4, p. 1-22. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Survey, 375 South Euclid Avenue, Tucson, AZ 85719; Regional Wetland Coordinator, U.S. Fish and Wildlife Service, 500 Gold Avenue, SW, Room 4012, Albuquerque, NM 87103 Prepared by L.K. Ham, U.S. Geological Survey, and S.K. Bulmer and Tanna Thornburg, Arizona State Parks 120 National Water Summary Wetland Resources: STATE SUMMARIES U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources 121 Arkansas Wetland Resources We'etlands occupy about 8 percent of the land surface in Arkan- sas (Dahl, 1990) and are an important but threatened resource. Historically, wetlands occupied a much larger area of the State and greatly influenced early economic development. At the time the first Europeans settled in the area, wetlands occupied about 28 percent of what is now Arkansas. These wetlands consisted largely of vast bottom-land forests and swamps bordering the Mississippi River and other rivers and streams. The forested wetlands contained abundant bottom-land trees such as cypress, tupelo gum, sycamore, birch, cottonwood, and several species of oak that provided a source of timber for domestic and economic development. As the forests were cleared and the wetlands were drained, the fertile bottom land was opened up to agriculture, which eventually became the mainstay of the local economy. The loss of wetlands to agriculture and urban- ization and the associated loss of wildlife habitat have slowed but continue to be a major concern (Arkansas Department of Pollution Control and Ecology, 1992). Wetlands provide critical habitat for many important plants and animals in Arkansas. Seven endangered species and three threatened species of plants and animals inhabit wetlands in the State (Curtis James, U.S. Fish and Wildlife Service, written commun., 1993). Some of the endangered or threatened species of animals and plants in Arkansas that rely on wetlands sometime during their lives in- clude the bald eagle, the red-cockaded woodpecker, the grey bat, the pink mucket pearly mussel, the fat pocketbook pearly mussel, and the pondberry. Arkansas bottom-land forested wetlands provide important habitats for many species of fish. Seasonal flooding of river flood plains provides access to new or expanded food supplies during periods of increased energy needs of fish at critical stages in their reproductive and growth cycles (Jack Kilgore, John Baker, and R.D. Smith, U.S. Army Corps of Engineers, unpub. data, 1993). Wetlands in Arkansas, especially those in the Mississippi River Valley, are a critical component of the series of wetland habitats along the Mississippi Flyway, which is used by millions of migra- tory birds each year. The management board of the Lower Missis- sippi Valley Joint Venture for the restoration of Mississippi Flyway waterfowl populations considers the protection and preservation of wetlands in Arkansas to be a key to the success of their program (Lower Mississippi Valley Joint Venture Management Board, 1990), Wetlands in the Cache-Lower White River system (fig. 1) in the Mississippi Flyway have been designated as one of nine "Wetlands of International Importance" in the United States under provisions of the Convention on Wetlands of International Importance Espe- cially as Wildlife Habitat (Arkansas Department of Pollution Con- trol and Ecology, 1992), which is known informally as the Ramsar Convention after Ramsar, Iran, where the convention was held in 1971. Wetlands modify the water quality and hydrology of conter- minous water bodies by serving as nutrient, sediment, and sediment- related toxic-materials traps. For example, Kleiss (1993), in a study on the Cache River in eastern Arkansas, found that there was a sub- stantial decrease in suspended sediment and nitrate loads in the river after it passed through a wetland. Wetlands also mitigate the sever- ity of floods and droughts by serving as floodways and reservoirs for surface waters and recharge-discharge areas for ground water (Mitsch and Gosselink. 1993). Wetlands in Arkansas also provide recreational opportunities for hunting, fishing, bird watching, and boating to thousands of people each year. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deep- water habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and oth- ers, 1979). The distribution of wetlands and deepwater habitats in Arkansas is shown in figure 2/4; only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Arkansas are described below. System Palustrine. Wetland description Wetlands in which vegetation is predominantly trees (forested wetlands); shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted, herbaceous plants (persistent- and nonpersistent-emergent wetlands); or sub- mersed and (or} floating plants (aquatic beds). Also, intermittently to permanently flooded open-water bodies of less than 20 acres in which water is less than 6.6 feet deep. Wetlands within an intermittently to permanently flooded lake or reservoir. Vegetation, when pres- ent, is predominantly nonpersistent emergent plants {nonpersistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds), or both. Wetlands within a channel. Vegetation, when pres- ent, is same as in the Lacustrine System. Most of the wetlands in Arkansas are palustrine forested, scrub- shrub, and nonvegetated wetlands (Arkansas Department of Pollu- tion Control and Ecology, 1992; U.S. Fish and Wildlife Service, 1992). The most extensive areas of wetlands in the State lie along the major rivers, such as the lower Mississippi, Arkansas, Red, White, and Little Rivers and their principal tributaries in the Mis- Lacustrine Riverine.. Figure 1. Black Swamp, a wetland along the Cache River. The Cache-Lower White River wetlands have been designated "Wet- lands of International Importance" under the provisions of the 1971 Ramsar Convention. (Photograph by Ed Morris, U.S. Geological Survey.) 122 National Water Summary Wetland Resources: STATE SUMMARIES sissippi Alluvial Plain, South Central Plains, and Arkansas Valley Ecoregions (fig. 2A and 26). Other wetlands are scattered through- out the State and are associated with springs and seeps in the Ouachita Mountains and Ozark Highlands. Arkansas has 7 National Wildlife Refuges, 1 National Scenic River System, 1 National For- est, 17 State wildlife management areas, and 6 State parks that con- tain significant wetland areas. The larger wetlands in Arkansas generally are forested wetlands associated with the flood plains of rivers such as the Saline, Ouachita, and Little Rivers and Bayou Dorcheat. Mixed forested and scrub-shrub wetlands border the Cache, Black, and St. Francis Riv- ers and Taylor Bay. Little Bayou Meto is lined by an example of a mixed forested and emergent wetland, which is uncommon in Ar- kansas. Smaller wetlands with unique features include Centerville Pondberry and Coffee Prairie. These two wetlands contain plant species of special concern to the State. Coffee Prairie has been iden- tified by The Nature Conservancy and the Natural Heritage Com- mission as deserving of priority protection (U.S. Fish and Wildlife Service, 1992). HYDROLOGIC SETTING The existence of wetlands depends on geologic and hydrologic conditions that favor the retention of water and on hydrologic proc- esses that allow the water to accumulate (Winter and Woo, 1990). Wetland hydrology involves complex water-flow patterns that are affected by regional and local geology, topography, soil character- istics, and climate. Water in small wetlands can be supplied by local shallow ground-water flow systems, surface waters, or precipitation. In the mountainous areas of northern and western Arkansas, wet- lands typically are small and associated with springs. Larger wet- lands in southern and eastern Arkansas commonly receive water from local and regional ground-water flow systems and surface water. Surface water collects in topographic lows, and ground water commonly discharges in these areas. The rate at which water per- colates downward from these wetlands to ground-water systems or upward from ground-water systems to the wetlands is a function of local hydraulic conditions and geologic characteristics. WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown ^^H Predominantly wetland Predominantly deepwater habitat B ECOREGIONS A. South Central Plains B. Ouachita Mountains C. Arkansas Valley D. Boston Mountains E. Ozark Highlands F. Mississippi Alluvial Plain Figure 2. Wetland distribution in Arkansas and ecoregions of the State. A, Distribution of wetlands and deepwater habitats. B, Ecoregions. (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 1991. B, Ecoregions from Omernik, 1987; landforms data from EROS Data Center.) National Water Summary Wetland Resources: ARKANSAS 123 In some parts of the State, seasonal fluctuations in precipita- tion result in seasonal differences in the flooded area of wetlands. However, precipitation in the State is abundant and averages from 40 to 56 inches per year. No season is without at least moderate amounts of precipitation (Freiwald, 1985); therefore, seasonal varia- tions in the water content of most wetlands in the State are small. Major wetlands in Arkansas are closely associated with the State's large river flood plains, and most are influenced by the Mis- sissippi River. In the northeastern and eastern parts of the State, many streams flow through channels cut into alluvium sands, silts, and clays deposited by the Mississippi River. These streams in- clude the Black, White, St. Francis, and Cache Rivers and Bayou Deview (Arkansas Department of Pollution Control and Ecology, 1992). The flood plain of the Mississippi River is an area of little to- pographic relief that has been subjected to frequent flooding. This frequent flooding has resulted in the establishment of large stands of water-tolerant bottom-land trees and the development of back- water swamps associated with such hydrologic conditions (fig. 3A, 3,6, and 3C). The continued survival of these forested and scrub- shrub wetlands depends on continued seasonal flooding and dewa- tering cycles. Disruption of the flooding and dewatering cycle can adversely affect plant and animal communities in wetlands and al- ter the size and type of the wetlands. When the flooding cycle is prevented, such as when wetland areas are leveed or ditched and drained, the water-tolerant plant species commonly are replaced by less water-tolerant trees and shrubs. Once the threat of flooding is reduced, these areas often are cleared for agriculture. When wet- lands are drained or cleared, they can no longer trap sediments and sediment-bound contaminants, remove nutrients from flood waters, or provide off-channel storage to lessen the severity of floods. Also, nursery habitat for certain species offish and invertebrates is greatly restricted when wetlands are drained. This can result in lower fish and invertebrate populations. Conversely, in forested wetlands sub- jected to permanent flooding, such as occurs when a river is dammed, the establishment of new trees will cease and the existing trees will die. Eventually, the forested wetland will be replaced by open water. TRENDS The area that is now Arkansas began losing wetlands shortly after the arrival of European settlers and has lost more wetland acres than any inland State in the Nation (Scott Yaich, U.S. Fish and Wildlife Service, written commun., 1993). Wetland loss in Arkan- sas from the 1780'stothe 1980's was about 72 percent (Dahl, 1990), and many remaining wetlands have been altered from their natural state. Arkansas originally contained about 9,848,600 acres of wet- lands before the arrival of European settlers. By 1937, wetland area in the State had decreased to about 4,900,000 acres (U.S. Fish and Wildlife Service, 1992). The rate of wetland loss increased after World War II owing to the increased availability of mechanized equipment. Wetland loss was about 36 percent of the remaining wetland area from 1957 to 1967 but decreased to about 14 percent from 1977 to 1985 (Arkansas Department of Pollution Control and Ecology, 1992). Holder (1969) estimated that 90 percent of the wetland loss in the last 40 years was due to the expansion of soy- bean production. By 1993, more than 90 percent of Arkansas' origi- nal bottom-land forested wetlands had been converted to upland or other types of wetlands (Scott Yaich, U.S. Fish and Wildlife Ser- vice, written commun., 1993). The 72-percent wetland loss reported by Dahl (1990) represents total wetland loss in the State but does not account for conversion of natural wetlands to some other type of wetland or the creation of artificial wetlands. For example, some of the State's remaining wetland acreage includes small farm ponds, which are not high-quality wetland habitat (Scott Yaich, U.S. Fish A. During flooding PALUSTRINE WETLAND B. During flood recession PALUSTRINE WETLAND PALUSTRINE WETLAND AHuva Alluvium C. During low flow PALUSTRINE WETLAND Figure 3. Surface hydrologic interaction between a river and forested wetlands in the flood plain. A, During flooding. B, During flood recession. C, During low flow; note establishment of new trees. and Wildlife Service, written commun., 1993). Almost all of the cleared lands in the major wetland areas of the State were being farmed in the 1990's, although many of these areas are considered marginal for crop production because of the flooding hazard (U.S. Fish and Wildlife Service, 1992). Some of these marginal farmlands reverted to scrub-shrub wetlands when farming operations were discontinued. Even though the rate of wetland loss has declined in recent years, Arkansas continues to lo.se wetlands. Continuing threats to the remaining, primarily forested wetlands of the State a.s identi- fied by FWS (1992) include (1) drainage and flood protection, (2) dredging and stream channelization, (3) conversion of forested wetland to scrub-shrub, emergent, or open-water wetlands, (4) al- teration of drainage patterns, (5) construction of dikes and levees, and (6) discharge of pollutants. 124 National Water Summary Wetland Resources: STATE SUMMARIES Much of the historical wetland loss within Arkansas has been a result of Federal legislation. In 1850, the U.S. Congress passed the Swamp Land Act, which granted to Arkansas 7,686,575 acres of swamp and overflow lands considered unfit for cultivation. The objective of the act was to help control floods in the Mississippi River Valley and encourage the drainage and clearing of these "sub marginal" lands for agriculture by allowing sale of these lands to private individuals for development (Shaw and Fredine, 1971). Congress passed the Flood Control Act of 1928 in response to the disastrous 1927 floods in the Mississippi Valley. This act removed the requirement for local interests to pay one-half of the cost of levee construction on the Mississippi River. The passage of this bill re- sulted in the accelerated construction of a vast network of levees along the Mississippi River and its tributaries. The net effect of this and other flood-control acts was the conversion of thousands of acres of wetlands to agriculture due to the removal of the threat of fre- quent flooding (Arkansas Department of Pollution Control and Ecology, 1992). CONSERVATION Many government agencies and private organizations partici- pate in wetland conservation in Arkansas. The most active agencies and organizations and some of their activities are listed in table 1. Federal wetland activities. Development activities in Arkan- sas wetlands are regulated by several Federal statutory prohibitions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Har- bors Act; the 1972 Clean Water Act and amendments; the 1985 Food Security Act; the 1990 Food, Agriculture, Conservation, and Trade Act; and the 1986 Emergency Wetlands Resources Act. Section 10 of the Rivers and Harbors Act gives the U.S. Army Corps of Engineers (Corps) authority to regulate certain activities in navigable waters. Regulated activities include diking, deepening, filling, excavating, and placing of structures. The related section 404 of the Clean Water Act is the most often-used Federal legislation protecting wetlands. Under section 404 provisions, the Corps issues permits regulating the discharge of dredged or fill material into wetlands. Permits are subject to review and possible veto by the U.S. Environmental Protection Agency, and the FWS has review and ad- visory roles. Section 401 of the Clean Water Act grants to States and eligible Indian Tribes the authority to approve, apply conditions to, or deny section 404 permit applications on the basis of a pro- posed activity's probable effects on the water quality of a wetland. Most farming, ranching, and silviculture activities are not sub- ject to section 404 regulation. However, the "Swampbuster" provi- sion of the 1985 Food Security Act and amendments in the 1990 Food, Agriculture, Conservation, and Trade Act discourage (through financial disincentives) the draining, filling, or other alteration of wetlands for agricultural use. The law allows exemptions from pen- alties in some cases, especially if the farmer agrees to restore the altered wetland or other wetlands that have been converted to agri- cultural use. The Wetlands Reserve Program of the 1990 Food, Agriculture, Conservation, and Trade Act authorizes the Federal Government to purchase conservation easements from landowners who agree to protect or restore wetlands. The Consolidated Farm Service Agency (formerly the Agricultural Stabilization and Con- servation Service) administers the Swampbuster provisions and Wet- lands Reserve Program. The Natural Resources Conservation Service (formerly the Soil Conservation Service) determines com- pliance with Swampbuster provisions and assists farmers in the iden- tification of wetlands and in the development of wetland protection, restoration, or creation plans. The 1986 Emergency Wetlands Resources Act encourages wetland protection through funding incentives. The act requires Table 1 . Selected wetland-related activities of government agencies and private organizations in Arkansas, 1993 [Source: Classification of activities is generalized from information provided by agencies and organizations. , agency or organization participates in wetland-related activity;..., agency or organization does not participate in wetland-related activity. MAN, management; REG, regulation; R&C, resto- ration and creation; LAN, land acquisition; R&D, research and data collec- tion; D&l, delineation and inventory] Agency or organization FEDERAL Department of Agriculture Consolidated Farm Service Agency ............ Forest Service.................................................. Natural Resources Conservation Service . Department of Defense Army Corps of Engineers............................... Department of the Interior Fish and Wildlife Service............................... Geological Survey........................................... National Biological Service.......................... National Park Service .................................... Environmental Protection Agency.................................. STATE Department of Pollution Control and Ecology ............. Forestry Commission ......................................................... Game and Fish Commission ............................................. Natural Heritage Commission.......................................... Soil and Water Conservation Commission ................... PRIVATE Ducks Unlimited.................................................................. National Audubon Society ............................................... The Nature Conservancy.................................................. States to address wetland protection in their Statewide Comprehen- sive Outdoor Recreation Plans to qualify for Federal funding for State recreational land; the National Park Service (NFS) provides guidance to States in developing the wetland component of their plans. The FWS administers seven National Wildlife Refuges, includ- ing the 154,000-acre White River National Wildlife Refuge located along the lower White River in Arkansas. The FWS also administers wetland-acquisition programs and advises Federal and State agen- cies responsible for wetland conservation. Other Federal agencies that have management or monitoring responsibilities for wetlands in Arkansas include the NFS, the U.S. Forest Service (FS), and the U.S. Geological Survey (uses). The FS is responsible for the man- agement of wetlands in the State's National Forests. Buffalo National River, a segment of the Buffalo River under the jurisdiction of the NFS, has some small wetland areas associated with the river. The USGS collects information on the quantity and quality of many of the Nation's water resources, including its wetlands. State wetland activities. Arkansas has a Natural and Scenic Rivers program and a Natural Heritage program. These two pro- grams designate extraordinary and ecologically sensitive areas, in- cluding wetlands, within the State. A technical review committee made up of representatives from State agencies makes recommen- dations to the Governor on section 404 permits. The State has adopted a program administered by the Arkansas Department of Pollution Control and Ecology that applies an antidegradation policy to substantial alterations of a water body, including associated wet- lands. In addition, the Arkansas Soil and Water Conservation Com- mission and the Arkansas Forestry Commission have extensive re- sponsibilities concerning the management of the State's wetlands. The Arkansas Game and Fish Commission, the State's lead wildlife agency, has a long-standing commitment to protect wetlands National Water Summary Wetland Resources: ARKANSAS 125 within the Mississippi River Valley because of the area's importance to wildlife, particularly to migratory birds. The Arkansas Game and Fish Commission owns or controls more than 174,000 acres in 14 wildlife management areas within the Mississippi River Valley, much of which consists of wetlands. The Arkansas Game and Fish Com- mission and the Arkansas Natural Heritage Commission are com- mitted to additional investment in the Mississippi River Valley and have begun developing comprehensive plans for these activities. The Game and Fish Commission has developed the Cache-Lower White Rivers Joint Venture under the North American Waterfowl Manage- ment Plan. The objective of this program is to protect bottom-land habitat in the Cache River and lower White River Basins, which constitute the second-largest area of contiguous bottom-land habi- tat in the Mississippi River Valley, second only to the Atchafalaya River Basin in Louisiana. In 1990, protected Federal and State lands in the Joint Venture were designated "Wetlands of International Significance" under the provisions of the 1971 Ramsar Convention, which produced an international agreement for cooperation in the conservation of wetland habitats. In 1988, the Natural Heritage Commission, in cooperation with the Arkansas Chapter of The Nature Conservancy, began to develop the White River-Lower Arkansas River Megasite plan (Lynch and others, 1992). This plan presents a landscape-level design inven- tory of an ecologically intact, biologically diverse bottom-land sys- tem that includes more than 550,000 acres. More than 280,000 acres in this habitat system are public lands. The boundaries of this habi- tat system differ somewhat from those of the high-priority water- fowl habitat defined by the Cache-Lower White Rivers Joint Ven- ture, although both are in the Mississippi River Valley. Regional and private wetland activities. The Arkansas Chap- ter of The Nature Conservancy is involved in an effort to protect and restore the forested wetlands of the Mississippi River Alluvial Plain in Arkansas as part of a coordinated effort to protect wetlands of that region in seven States. The National Audubon Society and Ducks Unlimited also are involved in the protection and restoration of wetlands and the critical wildlife habitats they contain. More than 50 percent of the remaining bottom-land forests in the Mississippi River Valley are in private ownership and much of these forests are commercial timberlands owned by the forest-prod- ucts industry. Most of these commercial timberlands are a critical part of the Lower White-Lower Arkansas River Megasite plan be- cause they occupy key locations contiguous with and connecting public lands within the system. References Cited Arkansas Department of Pollution Control and Ecology, 1992, Wetlands, Chapter 4 of water quality inventory report, 1992: Little Rock, Arkan- sas Department of Pollution Control and Ecology, p. 45-48. Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Dahl, T.E., 1990, Wetlands Losses in the United States, 1780's to L980's: U.S. Fish and Wildlife Service Report to Congress, 13 p. Freiwald, D.A., 1985, Average annual precipitation and runoff for Arkan- sas, 1951 80: U.S. Geological Survey Water-Resources Investigations Report 84-4363, scale 1:1,000,000. Holder, Trusten, 1969, Disappearing wetlands in eastern Arkansas: Little Rock, Arkansas Planning Commission, 71 p. Kleiss, B.A., 1993, An ecosystem study of bottom land hardwood wetlands associated with the Cache River, eastern Arkansas, in Landin, M.C., ed., Wetlands, Proceedings of the 13th Annual Conference Society of Wetland Scientists, New Orleans, La.: Utica, Miss., Society of Wet- land Scientists, South Central Chapter, p. 3137, Lower Mississippi Valley Joint Venture Management Board, 1990, Conserv- ing waterfowl and wetlands: Vicksburg, Miss., North American Wa- terfowl Management Plan. Lower Mississippi Valley Joint Venture, 32 p. Lynch, J.M., Baker, W.W., Foti, Tom, and Peacock, Lance, 1992, The White River-lower Arkansas River megasite A landscape conservation design project: Little Rock, Arkansas Natural Heritage Commission and the Arkansas Nature Conservancy, 81 p. Mitsch, W.J., and Gosselink, J.G., 1993, Wetlands (2d ed.): New York. Van Nostrand Reinhold Company, 722 p. Omernik, J. M., 1987, Ecoregions of the United States Map supplement: Annals of the Association of American Geographers, v. 77, no. 1, scale 1:2,500,000. Shaw, S.P., and Fredine, C.G., 1971, Wetlands of the United States Their extent and their value to waterfowl and other wildlife: U.S. Fish and Wildlife Service Circular 39, 67 p. U.S. Fish and Wildlife Service, 1992, Regional wetlands concept plan Emergency wetlands resources act, southeast region: Atlanta, Ga., U.S. Fish and Wildlife Service, 259 p. Winter, T.C., and Woo, Ming-Ko, 1990, Hydrology of lakes and wetlands: in Wolman, M.G., and Riggs, H.C., eds., Surface water hydrology: Boulder, Colo., Geological Society of America, The geology of North America, v. O-l, chap. 8, p. 159-187. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Survey, 401 Hardin Road, Little Rock, AR 72211; Regional Wetland Coor- dinator, U.S. Fish and Wildlife Service, 1875 Century Building, Suite 200, Atlanta, GA 30345 Prepared by Charles R. Demas and Dennis K. Demcheck, U.S. Geological Survey 126 National Water Summary Wetland Resources: STATE SUMMARIES U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources 127 California Wetland Resources V-.alifornia has about 454,000 acres of nonagricultural wetlands; more than 90 percent of the State's wetlands have been drained, mostly for agricultural purposes. Before significant agricultural con- version began, about 5 million acres of wetlands supported lush aquatic vegetation and provided habitat for hundreds of species of fish and wildlife as well as food, clothing, protection from preda- tors, and transportation for native Americans. California's wetlands provide stopover, wintering, and breed- ing habitat for vast numbers of waterfowl (fig. 1). The Sacramento- San Joaquin River Delta is the largest remaining wetland area in the State. The delta's wetlands regularly harbor as much as 15 percent of the waterfowl on the Pacific Fly way, the bird-migration corridor extending from the southern tip of South America to Alaska. Al- though significantly reduced in size since predevelopment times, wetlands in the delta are a source of large amounts of plant and algal materials that are the basis of complex food systems in the wetlands themselves and downstream in the estuaries of San Francisco Bay. California's wetlands have significant environmental and eco- nomic value for humans and wildlife. Wetlands provide temporary storage of floodwaters, reducing downstream damage, and serve as buffers against erosion. Marshes in the Sacramento-San Joaquin River Delta and many coastal marshes act as freshwater barriers to seawater intrusion of aquifers. Wetlands also trap sediment and ab- sorb many waterborne pollutants and excess nutrients. Wetlands provide fish and wildlife habitat; inland wetlands are excellent habi- tat for bass, catfish, bluegill, sunfish, crappie, geese, ducks, wading birds, and many species of amphibians. Wetlands offer recreational and educational activities, as well as opportunities for scientific studies. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deep- water habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and oth- ers, 1979). The distribution of wetlands and deepwater habitats in California is shown in figure 2A\ only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this Figure 1. Suisun Marsh provides habitat to many kinds of water- fowl. Agricultural and urban encroachment has reduced and con- tinues to threaten valuable wetlands. (Photograph courtesy of the Bureau of Reclamation.) summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Califor- nia are described below. System Palustrine. Lacustrine Riverine, Estuarine, Marine, Wetland description Nontidal and tidal-freshwater wetlands in which vegetation is predominantly trees (forested wet- lands}; shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted herba- ceous plants (persistent- and nonpersistent- emergent wetlands); or submersed and (or) floating plants (aquatic beds). Also, intermit- tently to permanently flooded open-water bod- ies of less than 20 acres in which water is less than 6.6 feet deep. Nontidal and tidal-freshwater wetlands within an intermittently to permanently flooded lake or reservoir larger than 20 acres and (or) deeper than 6.6 feet. Vegetation, when present, is pre- dominantly nonpersistent emergent plants (non- persistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds), or both. Nontidal and tidal-freshwater wetlands within a channel. Vegetation, when present, is same as in the Lacustrine System. Tidal wetlands in low-wave-energy environments where the salinity of the water is greater than 0.5 part per thousand (ppt) and is variable owing to evaporation and the mixing of seawater and freshwater. , Tidal wetlands that are exposed to waves and cur- rents of the open ocean and to water having a salinity greater than 30 ppt. The FWS National Wetland Inventory currently (1993) is map- ping California's wetlands and compiling statewide acreage data. However, that inventory is not scheduled to be completed until the late 1990's, and there are no other systematically compiled data concerning statewide wetland acreage. Dahl (1990), on the basis of Central Valley (fig. 25) acreage data in Frayer and others (1989) and approximations by the FWS, estimated that California had 454,000 acres of wetlands in the mid-1980's 0.4 percent of the State's area. Frayer and others (1989) reported the results of a systematic survey of Central Valley and Sacramento San Joaquin River Delta wetlands conducted in the mid-1980's. The study indicated that there were about 378,800 acres of freshwater and estuarine nonagricul- tural wetlands and 658,600 acres of flooded rice fields, most of which are converted wetlands. Field and others (1991) reported that the coastal counties of California had about 198,500 acres of palustrine, estuarine, and marine wetlands on the basis of interpre- tation of aerial photography done from the mid-1970's to the mid- 1980's. Acreage data for the alluvial basins of northern California, montane wetlands in the Sierra Nevada and Cascade Range, and desert wetlands in southern California are not yet available. The 378,800 acres of nonagricultural wetlands in the Central Valley and Sacramento-San Joaquin River Delta includes approxi- mately 318,900 acres of palustrine wetlands and 59,900 acres of 128 National Water Summary Wetland Resources: STATE SUMMARIES C AREA HAVING ANNUAL WATER DEFICIT Area of water deficit San tttti/o Myx \ ( I '* S "- tlkDorn Slough \ i \ Na{ional Estuarine v. A i n"-- ,h Reserw l ' ^ r '\k Ti| uana Estuary National Esiuanne Research Reserve Tijuana Kivci WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown ^^^H Predominantly wetland [ Predominantly deepwater habitat yyyy/\ Area typified by a high density of small wetlands B PHYSIOGRAPHIC DIVISIONS Figure 2. Wetland distribution in California and physical and climatological features that influence wetland distribution in the State. A, Distri- bution of wetlands and deepwater habitats. B, Physiography. C, Moisture balance. (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 1991. B, Physiographic divisions modified from Fenneman, 1946; landforms from EROS Data Center. C, Modified from Thomas and Phoenix, 1976.) National Water Summary Wetland Resources: CALIFORNIA 129 estuarine wetlands (Prayer and others, 1989). The palustrine wet- lands are of three types: (1) Those associated with or adjacent to rivers primarily overflowed lands, sloughs, and bypasses; (2) those associated with grasslands mainly on the alluvial fans of the eastern and western slopes of the valley, which contain numer- ous vernal pools during normal-precipitation years; and (3) marshes mainly in the central lowlands of the Sacramento and San Joaquin River drainage basins and the Tulare Basin. The Central Val- ley's estuarine wetlands are in the Suisun Marsh in the westernmost part of the Sacramento-San Joaquin River Delta. On the basis of data from Field and others (1991), most wet- lands in California's coastal counties, which are primarily in the Coast Ranges, are classified as palustrine. Of the 198,500 coastal wetland acres, 46,700 acres are fresh marsh (palustrine emergent wetlands), 77,800 acres are palustrine forested or scrub-shrub wet- lands, 21,700 acres are salt marsh (estuarine emergent wetlands), and 52,200 acres are tidal flats (estuarine unconsolidated-shore wetlands), which are mostly nonvegetated. (The acreages for indi- vidual wetland types do not total 198,500 because of rounding.) The mountains of California contain palustrine, lacustrine, and riverine wetlands. These wetlands have not been inventoried to date (1993) because of their isolated and widely different topographic and ecological settings. Construction of reservoirs on the upland reaches of creeks and major rivers in the Sierra Nevada and Cas- cade Range has created additional wetland acreage. Palustrine wet- lands of the Sierra, Cascades, and parts of the Coast Ranges are emergent wetlands commonly called bogs or meadows and forested or scrub-shrub wetlands called swamps. These wetlands are typi- cally small, sometimes only a few thousand square feet, and exist randomly among coniferous forests at altitudes generally higher than 3,000 to 3,500 feet. The desert basins of southeastern California contain lacustrine and palustrine wetlands referred to as playas, which are lakebeds that are intermittently flooded. Rogers, Soda, Searles, China, and Rosamond Lakes are large playas. The typical playa is nonvegetated except where fissures and sinklike depressions provide intermittent sources of water by pooling rainfall and overland flow. In unusu- ally wet years and for periods following them, plants whose roots reach the water table, such as saltbrush, rabbitbrush, tamarisk, and mesquite, grow in areas of shallow ground water and around dry springs (CJ. Londquist, U.S. Geological Survey, written commun., 1993). Mono Lake, a saline lake remnant of a much larger ice-age lake in the Basin and Range east of the central Sierra Nevada (fig. IB), supports an abundance of brine shrimp and brine flies that are a significant food source for eared grebes, avocets, plovers, sandpip- ers, gulls, ducks, and phalaropes (Bakker, 1984). Because of the high salinity of the lake water, only salt-tolerant plants such as stinkweed, goosefoot, and salt or alkali grass grow around the lake. In the Southern California Desert near the California-Mexico border is a type of palustrine desert wetland known popularly as an "oasis." These emergent, scrub-shrub, and forested wetlands sup- port willow, catclaw, mesquite, cottonwood, tamarisk, reeds, arrow- wood, and in some places, sedges, tules, and cattails. But the most distinctive plants of the oases are the native fan palms (Bakker, 1984). HYDROLOGIC SETTING To understand the existence of once vast natural wetlands in a State that has an average annual precipitation of about 20 inches and is commonly considered to be semiarid to arid, California's hydrog- raphy and topography must be examined. Most of the State has a natural annual water deficit (fig. 2C). However, in the areas having a natural water surplus, precipitation ranges from 40 to as much as 90 inches per year, most of that being snowfall in the Sierra Nevada, Cascade Range, and Klamath Mountains. Annual precipitation amounts can differ widely from year to year because of variability in the Pacific storm track. Mountain ranges induce precipitation at the higher altitudes and create "rain shadows" (dry areas) in the leeward valleys and plains. In California, nearly continuous ranges of coastal mountains extend from the Oregon border to Mexico, and these ranges are paralleled by the southern Cascade Range and the Sierra Nevada about 150 miles farther inland (fig. 2B). Between the two ranges, in the rain shadow of the Coast Ranges, lies the Central Valley, nearly 400 miles long and 70 miles wide. In the rain shadow of the south- ern Cascade Range, the Sierra Nevada, and the coastal mountains of southern California are the Basin and Range and Southern Cali- fornia Desert physiographic provinces. Central Valley wetlands. Streams originating in the Sierra Nevada carry 95 percent of the runoff entering the Central Valley. Before hydrologic modification associated with agriculture, much of the southern Sierra Nevada runoff flowed into the internally drained Tulare Basin, creating several large freshwater lakes that existed for more than 2,000,000 years (Page, 1986). The largest, Tulare Lake, formed a large lacustrine wetland extending over 600 square miles. Streams flowing in the trough of the Central Valley typically have low gradients and almost imperceptible natural levees. Consequently, before the rivers were contained by irrigation and flood-control projects, flood plains were wide, and in many years the entire valley was inundated by floodwater. Overbank flooding created thousands of acres of marshland and tens of thousands of vernal pools. Despite flood-control projects since the mid-1850's, overbank flooding still can occur in wet years. In the years before flood-control and irrigation projects, shal- low water tables supported large areas of wetlands on the valley floor. However, as a result of agricultural drainage, ground-water withdrawal, building of upland diversion dams, and flood-control projects, the original flow paths of water into the Central Valley and most of California's other alluvial basins have been altered, and the valley's hydrology is now generally as shown in figure 3A. Floods no longer regularly cover the valley floors but are diverted to crop- land, stored, or channeled. Ground-water levels under the valley floors have been drawn down to such an extent that recharge is pri- marily from irrigation, and discharge is mainly to large centers of ground-water pumping (Bertoldi and others, 1991). Most of the valley's wetlands are now sustained by controlled application of water (Frayer and others, 1989). Many wildlife refuges in the Central Valley use irrigation drain water either as a part or as the total source of water. Until 1986,1,200 acres of ponds in the Kesterson National Wildlife Refuge (fig. 2A) were partly sustained by agricultural drain water from the west side of the San Joaquin Valley. In 1983, the FWS discovered an unusu- ally high incidence of deformed or dead birds in the refuge. Studies of the drain water entering the ponds and of the water in the ponds showed that the deformities were caused by high concentrations of selenium in the drain water. The Bureau of Reclamation (BOR) implemented a plan to mitigate the effects of the drain water at the refuge by stemming the flow of agricultural drain water into the refuge and eliminating all aquatic habitat in the areas of the con- taminated ponds. Surface water is now imported into the refuge. Estuarine wetlands. California's estuaries have a high de- gree of variability in their physical and hydrologic environment. For most of the year, coastal estuaries, such as the Suisun Marsh below the confluence of the Sacramento and San Joaquin Rivers (and the Sacramento-San Joaquin Delta wetlands under natural conditions) are sustained by brackish to saline water. In the wet season during winter, they can become completely fresh. In addition, streamflow varies substantially, from none in many years to floods in wet years. There is little emergent wetland acreage remaining in the Sac- ramento-San Joaquin River Delta. After World War I, nearly all 130 National Water Summary Wetland Resources: STATE SUMMARIES delta marshland had been transformed to the series of improved channels and leveed islands that exist to the present (fig. 36). The delta soils are predominantly organic peat, and in agricultural use have oxidized extensively, causing land surfaces to subside to more than 15 feet below sea level within the leveed islands (California Department of Water Resources, 1993) so that emergent wetlands can exist only on the margins of the delta. Three of California's estuarine wetlands have attracted national and international attention. The largest of these wetland areas is the complex system of over 1,000 miles of waterways in the Sacra- mento-San Joaquin River Delta and three bays within a 1,200- square-mile area of central California. The bays, beginning with the most landward, are Suisun, San Pablo, and the largest, San Fran- cisco. About 70 percent of California's water supply originates in the Sierras, flows through the Central Valley into the bay-delta sys- tem, then discharges into the Pacific Ocean at San Francisco Bay. Two other, smaller estuarine wetlands, Elkhorn Slough on Monterey Bay and the Tijuana River estuary at San Diego, have been included in the National Oceanic and Atmospheric Administration's (NOAA) National Estuarine Research Reserves. Such reserves are defined as "classes of ecosystems worthy of research and educa- tion, yet different enough to warrant selection as a distinct regional type" (Zedler and others, 1992). The recent geologic factors that shape these estuaries are the forces of slowly rising sea level, which causes inland migrations of the estuaries, and tectonic uplift, which partly offsets the effects of a rising sea level. Deep submarine can- yons and unusual shoreline configurations affect the size and con- dition of both estuaries. Longshore drifting and currents have not been measured, but the effects are well known. Beach erosion has caused landward movement of the estuarine shorelines and subse- quent salinity changes. After decades of study at the Tijuana Na- tional Estuarine Research Reserve, restoration programs are under- way. Montane wetlands. The most common types of montane wetlands in California are meadows, which are palustrine wetlands with persistent emergent vegetation (fig. 3C and 3D}. Meadows in California have been best studied in the Sierras, where they are es- timated to compose about 10 percent of the total area (Ratliff, 1985). At higher altitudes, glacial cirques commonly contain small pools or lakes known as tarns. Meadows can develop when tarns fill with sediment, peat, or both. California's mountains are geomorphologically dynamic be- cause of glaciation, tectonic uplift, and volcanic eruptions in the recent geologic past. Dynamic features include glacially scoured depressions, moraines, and till and outwash deposits resulting from landslides and mudflows and from volcanic debris and lava flows that impede the movement of water from precipitation and snow- melt, leading to the formation of wetlands. Impoundments can form A. Central Valley COAST RANGE RIVERINE WETLAND | PALUSTRINE WETLAND SIERRA NEVADA RIVERINE WETLAND RIVERINE WETLAND S LACUSTRINE WETLAND ^4^^y^ 1L1!£%$ Granite EXPLANATION *- Direction of ground-water flow Average water table Scrub-shrub vegetation - _ Forest vegetation Emergent vegetation Farmed crops ^| Glacial till [ \ Basin-fill sediment and alluvium 1^1 Peat ^ I Confining bed or interbed Note: Vertical scale greatly exaggerated B. Sacramento-San Joaquin River Delta RIVERINE WETLAND PALUSTRINE WETLANDS ESTUARINE WETLANDS Figure 3. Generalized hydrologic setting of wetlands in California. A, Central Valley. B, Sacramento-San Joaquin River Delta. National Water Summary Wetland Resources: CALIFORNIA 131 C Sierra Nevada LACUSTRINE WETLANDS PALUSTRINE WETLAND Centra Valley E. Southern California Desert/Basin and Range Figure 3. Continued. Generalized hydrologic setting of wetlands in California. C, Sierra Nevada. D, Coast and Coast Ranges, f, Southern California Desert and Basin and Range. as a result of landslides or mining, road construction, and other human activities. Beavers create wetlands as a result of dam building. An example of a landslide- created wetland can be found in Mirror Lake at the base of Half Dome in Yosemite National Park. The lake is filling with sediment, and vegetation is becoming established. Meadows form in several topographic positions: depressions in valley bottoms, on glacially gouged surfaces, in glacial moraines with surface depressions where water is held, and on slight to moderate slopes where ground water discharges into fine-textured soils (commonly glacial or landslide deposits) at a rate greater than il can be released to streams and the at- mosphere. Meadows can have a range of hydrologic charac- teristics, from seasonally wet from snowmelt to satu- rated throughout the year. A single meadow can have several different hydrologic regimes, each supporting different vegetative communities (Ratliff, 1985). Meadows can be hydrologically dependent on both surface and ground water. Recent studies indicate that ground water is more important to meadow wetlands than previously thought (Akers, 1986; Winter and Woo, 1990). The present hydrologic condition of meadows in the Sierras, and likely elsewhere in California, ranges from slightly to highly altered; however, no systematic evaluation has been reported. Grazing of livestock since the mid-1850's disturbed many meadows enough to cause erosion, which in turn affected the hydrologic regime and the vegetative communities. More recently, intensive recreational use has contributed to degraded meadow conditions as well. Restoration of meadow vegetation to support grazing by livestock and wild- life requires that the hydrologic regime first be restored (Ratliff, 1985). Southern California Desert/Basin and Range Wetlands. Southeastern California from the Mexico border to the eastern flank of the Sierra Nevada lies in the rain shadow of the mountain ranges to the west. Precipitation is very low and temperatures are very high. Water for wetlands typically is supplied by moun- tain front creeks, springs, seeps, pools, and in more recent times, irrigation canals (fig. 3£). The largest wetlands in the region are playas, which typically are dry much of the year. Playas receive water from inter- mittent surface flows and from direct precipitation during infrequent storms. Water leaves playas through evaporation and transpiration because there is no sur- face drainage. Elsewhere, isolated springs and seeps support generally small marshes (cienagas) and other wetlands, such as oases. Where the water supply is relatively persistent but drainage is limited, saline wetlands can form. California's population is concentrated and in- creasing in the southern part of the State. The grow- ing demand for water and recreational activities (Bu- reau of Land Management, 1980) affects water re- sources and desert lands, especially wetland and ripar- ian areas. Ground-water pumping in the western Mojave Desert has caused fissures in playas at Edwards Air Force Base, and riparian vegetation has been adversely affected by declining ground-water levels. Increased amounts of water diverted for urban uses decreases the amount supporting wetlands. Rec- 132 National Water Summary Wetland Resources: STATE SUMMARIES reational activities and grazing have damaged riparian vegetation, contributing to a general decline in the quantity and quality of ri- parian wetlands. Owens Valley, a closed basin at the base of the Sierra Nevada's eastern escarpment, historically received runoff from the mountains that supported flow in the Owens River. This surface-water flow maintained Owens Lake and a ground-water level close to the ground surface of the valley floor. Diversions of surface water and ground water to Los Angeles since 1970 virtually eliminated wetlands de- pendent on surface water in the river and lake. However, ground- water-dependent vegetation on the valley floor has survived a low- ering of the water table by several feet by extending the root sys- tems (Sorenson and others, 1991). Its longer term survival and re- production have not been studied. TRENDS The earliest estimates of wetland acreage in California are those documented by the California State Engineers Surveys dating be- tween 1868 and 1886 (Hall, 1887). At that time, William H. Hall recorded nearly 5.2 million acres of land as swamps, lakes, bogs, and river overflow areas, most of which were located in the Central Valley. Dahl (1990) estimated that about 5 million acres of wetlands existed before large-scale agricultural conversions began. Of the original 5 million acres, nearly 4 million were palustrine, lacustrine, and riverine wetlands in the Central Valley, 700,000 were estuarine wetlands, 65,000 were palustrine and lacustrine wetlands of the Coast Ranges, 120,000 were palustrine, lacustrine, and riverine wetlands of the Cascade Range and Sierra Nevada, and 15,000 acres were riverine or palustrine wetlands of the interior basins and ranges. Significant wetland loss in California began in about 1850. In that year, the National Swamp and Overflowed Land Act conveyed all swamp and overflowed land, including delta marshes, from Fed- eral ownership to the State of California. In 1866, the California Legislature formed the Board of Swamp and Overflowed Land Commissioners to manage reclamation projects and proceeds from sales of swampland by the State. In 1869, the board relinquished its authority to individual county boards of supervisors. By about 1870, nearly all of California's wetlands were in private ownership, and subsidies were established to aid private developers in reclaim- ing swamplands (California Department of Water Resources, 1993). Between 1850 and 1920, about 70 percent of California's wet- land acreage was modified or converted to upland, largely by levee and drainage projects (Dennis and others, 1984). Nearly all of the reclaimed land was put into agriculture, helping to make California the leading agricultural State in the Nation by 1887. The diversion and redistribution of Sierran runoff water into the valley continued vigorously so that by 1939, 85 percent of the wetlands had been lost. By 1940, Tulare Lake, which had in post-European-settlement his- tory covered as much as 1,000 square miles, had been completely drained. Between 1938 and the early 1970's, construction of large- scale irrigation systems had modified more than 90 percent of the original wetlands. Although losses of wetlands have been large, some changes in land-use practices since about 1980 have caused increases or im- provements in wetland habitats. Since 1939, a switch from pastureland and row-crop farming to flooded rice paddies in the Sacramento Valley and parts of the San Joaquin Valley has increased palustrine wetlands by 41,000 acres (Prayer, 1989). Rice farmers, in conjunction with university and State researchers and private organizations, are developing methods to flood rice paddies during critical periods of occupation by migratory waterfowl. If these methods are perfected, several hundred thousand acres could be returned to seasonal wetland-habitat status while continuing to be used as agricultural lands. CONSERVATION Many government agencies and private organizations partici- pate in wetland conservation in California. The most active agen- cies and organizations and some of their activities are listed in table 1. Federal wetland activities. Development activities in Cali- fornia wetlands are regulated by several Federal statutory prohibi- tions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Harbors Act; the 1972 Clean Water Act and amendments; the 1985 Food Security Act; the 1990 Food, Agriculture, Conservation, and Trade Act; the 1986 Emergency Wetlands Resources Act; and the 1972 Coastal Zone Management Act. Table 1 . Selected wetland-related activities of government agencies and private organizations in California, 1993 [Source: Classification of activities is generalized from information provided by agencies and organizations. », agency or organization participates in wetland-related activity;.., agency or organization does not participate in wetland-related activity. MAM, management; REG, regulation; R&C, restora- tion and creation; LAM, land acquisition; R&D, research and data collection; D&l, delineation and inventory] Agency or organization ^ <^ <* v <^ ^ FEDERAL Department of Agriculture Consolidated Farm Service Agency........................... ... Forest Service................................................................. Natural Resources Conservation Service................ Department of Commerce National Oceanic and Atmospheric Administration................................................................. Department of Defense Army Corps of Engineers .............................................. Military reservations..................................................... Department of the Interior Bureau of Land Management...................................... Bureau of Reclamation ................................................. .. Fish and Wildlife Service.............................................. Geological Survey.......................................................... National Biological Service ......................................... ... National Park Service ................................................... Environmental Protection Agency.................................. STATE Environmental Protection Agency State Water Resources Control Board ...................... Regional Water-Quality Control Board ...................... Resources Agency California Coastal Commission.................................... Department of Conservation ....................................... ... Department of Fish and Game ..................................... Department of Parks and Recreation ........................ Department of Water Resources ................................ San Francisco Bay Conservation and Development Commission ............................................ State Reclamation Board ............................................. ... State Lands Commission............................................... State Coastal Conservancy.......................................... Wildlife Conservation Board........................................ SOME COUNTY AND LOCAL GOVERNMENTS Local planning authorities................................................ ... Reclamation districts ........................................................ Resource conservation districts .................................... Water districts .................................................................... PRIVATE California Waterfowl Association .................................. Ducks Unlimited.................................................................. Farmlands and Open-Space Foundation....................... National Audubon Society ............................................... ... Pacific Flyway Project....................................................... Sierra Club ........................................................................... The Nature Conservancy.................................................. Trust for Public Land .......................................................... National Water Summary Wetland Resources: CALIFORNIA 133 Section 10 of the Rivers and Harbors Act gives the U.S. Army Corps of Engineers (Corps) authority to regulate certain activities in navigable waters. Regulated activities include diking, deepening, filling, excavating, and placing of structures. The related section 404 of the Clean Water Act is the most often-used Federal legislation protecting wetlands. Under section 404 provisions, the Corps issues permits regulating the discharge of dredged or fill material into wetlands. Permits are subject to review and possible veto by the U.S. Environmental Protection Agency (EPA), and the FWS has review and advisory roles. Section 401 of the Clean Water Act grants to States and eligible Indian Tribes the authority to approve, apply conditions to, or deny section 404 permit applications on the basis of a pro- posed activity's probable effects on the water quality of a wetland. Most farming, ranching, and silviculture activities are not sub- ject to section 404 regulation. However, the "Swampbuster" provi- sion of the 1985 Food Security Act and amendments in the 1990 Food, Agriculture, Conservation, and Trade Act discourage (through financial disincentives) the draining, filling, or other alteration of wetlands for agricultural use. The law allows exemptions from pen- alties in some cases, especially if the farmer agrees to restore the altered wetland or other wetlands that have been converted to agri- cultural use. The Wetlands Reserve Program of the 1990 Food, Agriculture, Conservation, and Trade Act authorizes the Federal Government to purchase conservation easements from landowners who agree to protect or restore wetlands. The Consolidated Farm Service Agency (CFSA, formerly the Agricultural Stabilization and Conservation Service) administers the Swampbuster provisions and Wetlands Reserve Program. The Natural Resources Conservation Service (NRCS, formerly the Soil Conservation Service) determines compliance with Swampbuster provisions and assists farmers in the identification of wetlands and in the development of wetland pro- tection, restoration, or creation plans. The 1986 Emergency Wetlands Resources Act and the 1972 Coastal Zone Management Act and amendments encourage wetland protection through funding incentives. The Emergency Wetlands Resources Act requires States to address wetland protection in their Statewide Comprehensive Outdoor Recreation Plans to qualify for Federal funding for State recreational land; the National Park Service provides guidance to States in developing the wetland com- ponent of their plans. Coastal States that adopt coastal-zone man- agement programs and plans approved by NOAA are eligible for Fed- eral funding and technical assistance through the Coastal Zone Management Act. The EPA has authority, through the National Pollution Discharge System, National Pretreatment Program, Ocean Dumping/Dredging and Fill Program, and the Clean Water Act, to certify that permit- ted use of the State's waters is consistent with established water- quality objectives. Under the Clean Water Act, the EPA'S San Fran- cisco Bay-Estuary Project has a 5-year-program objective to develop a comprehensive management plan that would set operational stan- dards for nearly 700,000 acres of estuarine and marine wetlands. The U.S. Department of Agriculture, through local conserva- tion districts and the NRCS, administers the Federal Water Bank program with assistance from the CFSA and the State of California. The major objective of this program is to restore, preserve, enhance, or improve wetland habitat in important migratory waterfowl nest- ing and breeding areas. The NOAA administers the Coastal Zone Management Act, whose purpose is to increase awareness and understanding of the coastal environment and to increase the ability of States' coastal- zone-management programs to address problems. NOAA funding under the act assists California in coastal-plan development, includ- ing wetlands. Grants have been awarded to the California Coastal Plan and San Francisco Bay Plan. NOAA also administers the Na- tional Estuarine Research Reserve program, which provides site ac- quisition for preservation, research, and education. The FWS manages approximately 225,000 acres of land on 34 National Wildlife Refuges, Wildlife Management Areas, National Fish Hatcheries, or other wildlife facilities. Wetlands on these hold- ings are among the most important habitat along the entire Pacific Flyway. Through the American Waterfowl Management Plan, the FWS administers the Central Valley Joint Habitat Venture, which comprises private organizations and other public agencies that have pooled their resources to help meet a target of restoring and main- taining the diversity, distribution, and abundance of waterfowl at 1970s levels. State wetland activities. California has no single agency that implements an integrated plan for management of wetland resources, nor does the State have a wetlands-management policy. The Gover- nor's Office sets broad environmental goals for the State. The Governor's Office of Planning and Research has no regulatory au- thority but has substantial influence in guiding administration policy and is the clearinghouse for all documents promulgated under the California Environmental Quality Act of 1970. This act establishes the basic charter for protection of California's environment. A major policy under the act is the maintenance of fish and wildlife popula- tions, and the protection of wetlands is identified as a significant goal. The California Environmental Protection Agency administers four boards that set standards, control pollution, and improve the quality of the environment throughout the State. The State Water Quality Control Board administers the system of water rights and, through a series of nine Regional Water Quality Control Boards, is responsible for implementing section 108 of the Clean Water Act, which is a mandate to control nonpoint pollution. The boards also implement the provisions of the Porter-Cologne Act of 1969. These provisions provide for assessment reports identifying surface-wa- ter bodies that would not meet water-quality standards without non- point-source controls and allow for the development and implemen- tation of best-management practices for control of nonpoint sources of pollution. Several departments and commissions, operating within the overall administration of the Resources Agency of the State of Cali- fornia, have primary responsibility for the enhancement and pro- tection of wetland habitats. The Fish and Game Commission sets policy for the Department of Fish and Game. The Department has legislative authority to preserve, protect, and manage California's fish, game, and native plants, without respect to their economic value, and administers provisions of the State Endangered Species Act. The Department is responsible for wildlife management, col- lecting and managing data for waterfowl and nongame wildlife, disease research, wetland enhancement, and habitat development and management on 76 State-owned designated wildlife areas, eco- logical reserves, and other public lands. The Department of Fish and Game Stream or Lake Alteration Agreements are required for ac- tivities that result in changes in natural conditions in streams, lakes, channels, or crossings. The San Francisco Bay Conservation and Development Com- mission is authorized by the McAteer-Petris Act to analyze, plan, and regulate development activities in San Francisco Bay and along its shoreline. The Commission implements the San Francisco Bay Plan and the Suisun Marsh Protection Plan. The Commission also regulates dredging and filling in the bay, and in sloughs, marshes, certain creeks, and tributaries within 100 feet of the bay. The plan is subject to Coastal Zone Management Agency consistency review as a component of California's Coastal Plan, which is administered by the Commission. The Suisun Marsh Preservation Act was en- acted in 1977 to establish policies and programs in the Suisun Marsh Protection Plan. Local governments and districts must prepare lo- cal protection programs to bring their policies and ordinances into conformity with the provisions of the act. The Department of Water Resources is authorized by the Delta 134 National Water Summary Wetland Resources: STATE SUMMARIES Protection Act of 1988 to approve levee improvement in wetlands of the Sacramento-San Joaquin Delta. The Department is respon- sible for the State Water Project pumping facilities in the delta. The Department, as authorized by Delta Flood Protection Act of 1988, is involved in a levee-improvement program for flood protection that overlaps the North Delta Water Management Plans for widening channels, the South Delta Water Management Plans, and the Los Banos Grandes projects. The Department represents the State in Corps and BOR flood-control and water-development projects. County and local wetland activities. Resource Conservation Districts are authorized by Division 9 of the California Public Re- sources Code to assist the State in conserving soil and water re- sources, including wetlands. There are about 400 water, reclama- tion, and drainage districts in California, another 300 park and open- space districts, and 110 public-utility districts governed by Division 9 authority for conservation. In addition to special districts, county and city governments are required to have a general plan that has mandated elements in- cluding open space/conservation, safety, land use, and water circu- lation (Government Code, Section 65000 et seq.). There are no re- gional requirements for plan consistency among the counties and cities. The conservation element of the general plan must address the conservation, development, and utilization of natural resources, including water and its hydraulic force, forests, soils, rivers, and other waters, harbors, fisheries, wildlife, minerals, and other natu- ral resources. The open-space element defines provisions for open space for the preservation of natural resources, the managed pro- duction of resources, outdoor recreation, and public health and safety. Private wetland activities. Duck hunting clubs own most of the nonagricultural Central Valley and Suisun Bay wetlands and manage these areas for waterfowl. Ducks Unlimited is a major par- ticipant in the Joint Venture program of the FWS, in which public and private organizations cooperate to preserve wetlands. The Na- ture Conservancy, California Waterfowl Association, Pacific Fly- way Project, Trust for Public Land, Solano County Farmlands and Open Space Foundation, Sierra Club, and National Audubon Soci- ety have acquired sensitive lands for preservation and restoration. References Cited Akers, J.P., 1986, Ground water in the Long Meadows area and its relation with that in the General Sherman Tree area, Sequoia National Park, California: U.S. Geological Survey Water-Resources Investigations Report 85-4178, 15 p. Bakker, E.S., 1984, An island called California An ecological introduc- tion to its natural communities: Berkeley, University of California Press, 484 p. Bertoldi, G.L., Johnston, R.H., and Evenson, K.D., 1991, Ground water in the Central Valley, California A summary report: U.S. Geological Survey Professional Paper 1401-A, 44 p. Bureau of Land Management, 1980, California Desert Conservation Area Plan: Riverside, Calif., Bureau of Land Management, Desert District, 173 p. California Department of Water Resources, 1993, Sacramento- San Joaquin delta atlas: Sacramento, California Department of Water Resources, 121 p. Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report, FWS/OBS-79/31. 131 p. Dahl, T.E., 1990, Wetlands Losses in the United States, 1780's to 1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 13 p. Dennis, N.B., Marcus, M.L., and Hill, H., 1984, Status and trends of Cali- fornia wetlands Report to the California Assembly Resources Sub- committee: Sacramento, The California Assembly, 125 p. Fenneman, N.M., 1946, Physical divisions of the United States: Washing- ton, D.C., U.S. Geological Survey special map, scale 1:7,000,000. Field, D.W., Reyer, A.J., Genovese, P.V., and Shearer, B.D., 1991, Coastal wetlands of the United States: Rockville, Md., National Oceanic and Atmospheric Administration and U.S. Fish and Wildlife Service co- operative publication, 59 p. Prayer, WE., Peters, D.D., and Pywell, H.R., 1989, Wetlands of the Cali- fornia Central Valley Status and trends, 1939-1980's: Portland, Oreg., U.S. Fish and Wildlife Service Report, 29 p. Hall, W.H., 1887, Topographical and irrigation maps of the Great Central Valley of California, embracing the Sacramento, San Joaquin, Tulare and Kern Valleys and the bordering foothills for California: Sacra- mento, California Department of Engineering, scale about 1:380,160, 2 sheets. Page, R.W., 1986, Geology of the fresh ground-water basin of the Central Valley, California, with textural maps and sections: U.S. Geological Survey Professional Paper 1401 -C, 53 p. Ratliff, R.D., 1985, Meadows in the Sierra Nevada of California State of knowledge: U.S. Forest Service General Technical Report PSW-84, 52 p. Sorenson, S.K., Dileanis, P.O., and Branson, F.A., 1991, Soil water and vegetation responses to precipitation and changes in depth to ground water in Owens Valley, California: U.S. Geological Survey Water- Supply Paper 2730-G, 54 p. Thomas, H.E., and Phoenix, D.A., 1976, Summary appraisals of the Nation's ground-water resources, California region: U.S. Geological Survey Professional Paper 813-E, 51 p. Winter, T.C., and Woo, Ming-Ko, 1990, Hydrology of lakes and wetlands, in Wolman, M.G., and Riggs, H.C., eds., Surface water hydrology: Boulder, Colo., Geological Society of America, The Geology of North America, v. O-1, p. 159-187. Zedler, J.B., Nordby, C.S., and Kus, B.E., 1992, The ecology of Tijuana estuary, California A national estuarine research reserve: Washing- ton, D.C., National Oceanic and Atmospheric Administration Office of Coastal Resource Management, 151 p. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Survey, Room W-2233, Federal Building, 2800 Cottage Way, Sacramento, CA 95825; Regional Wetland Coordinator, U.S. Fish and Wildlife Service, 911 N.E. 11th Avenue, Portland, OR 97232 Prepared by G.L. Bertoldi and Walter C. Swain, U.S. Geological Survey U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources 135 Colorado Wetland Resources Weretlands cover only about 1.5 percent of Colorado but are eco- logically and economically valuable to the State. Wetlands provide important wildlife habitat during some part of their life cycle, as much as 90 percent of the State's fish and wildlife depend on ripar- ian habitats that include wetlands (Redelfs, 1980), and wetlands provide stopover and breeding grounds to migratory waterfowl. Wetlands also provide flood attenuation, bank stabilization, and water-quality improvement (fig. 1). Colorado's tourist industry ben- efits from the scenic beauty of the State's wetlands and deepwater habitats and from the opportunities they afford for recreational ac- tivities that include hunting, fishing, bird watching, nature photog- raphy, camping, hiking, and boating. Because wetland vegetation generally is more lush and productive than that in uplands, some wetlands are considered prime grazing land. Peat is mined from wetlands for use as a garden soil amendment. In the past, much of the State's mineral wealth was mined from placer gold and heavy- mineral deposits in riparian zones. These benefits are provided by diverse wetlands distributed across Colorado's plains, mountains, and deserts. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deep- water habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and oth- ers, 1979). The distribution of wetlands and deepwater habitats in Colorado is shown in figure 1A\ only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Colorado are described below. ine, 14 percent was mixed lacustrine and paiustrine, and 83 percent was paiustrine (U.S. Fish and Wildlife Service, 1955; i960). Palustrine wetlands in Colorado include forested wetlands in ripar- ian areas and near springs and seeps; scrub-shrub wetlands, such as willow carrs (thickets) and bottomland shrublands; emergent wetlands, such as marshes, fens, alpine snow glades, and wet and salt meadows; and aquatic-bed wetlands in ponds and lakes (Colo- rado Department of Natural Resources, 1992). Wetlands occupy about 1 million acres (1.5 percent) of Colo- rado (Dahl, 1990). In the Great Plains (fig. 2B), wetlands occur in the flood plains of the South Platte and Arkansas Rivers and in scat- tered locations throughout the plains. Wetlands generally are sparsely distributed in the Colorado Plateaus and Wyoming Basin. In the Southern and Middle Rocky Mountains, wetlands occur pri- marily in high mountain valleys and intermountain basins. HYDROLOGIC SETTING Wetlands form where there is a persistent water supply at or near the land surface. The location and persistence of the supply is a function of interdependent climatic, physiographic, and hydrologic factors such as precipitation and runoff patterns, evaporation, to- pography, and configuration of the water table. Precipitation (fig. 2C) and runoff rates differ annually and with season and location. The average annual precipitation in Colorado ranges from about 7 inches in the San Luis Valley to about 60 inches in some mountainous areas. Most runoff occurs in spring and early summer and is greatest in the mountains. Greater precipitation and runoff in the mountains are the principal reasons for the greater acreage of wetlands in the intermountain basins than in other re- gions of the State. In the mountains, melting snow is the primary source of runoff, whereas in the eastern plains, runoff is mostly from rainfall (Petsch, 1986). The timing and volume of runoff affect the establishment and function of riparian wetlands. High streamflow, which results from snowmelt in the mountains during spring and early summer, is essential for the maintenance of normally func- System Palustrine, Lacustrine Wetland description Wetlands in which vegetation is predominantly trees (forested wetlands); shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted, herbaceous plants (persistent- and nonpersistent-emergent wetlands); or sub- mersed and (or) floating plants (aquatic beds). Also, intermittently to permanently flooded open-water bodies of less than 20 acres in which water is less than 6.6 feet deep. Wetlands within an intermittently to permanently flooded lake or reservoir. Vegetation, when pres- ent, is predominantly nonpersistent emergent plants (nonpersistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds), or both. Wetlands with in a channel. Vegetation, when pres- ent, is same as in the Lacustrine System. There is no current (1993) estimate of statewide wetland acre- age in each of the systems. Inventories of wetland and open-water areas conducted in the 1950's estimated that 3 percent was river- Riverine Figure 1. Wetland in Tennessee Park, about 4 miles northwest of Leadville. This wetland receives acidic mine drainage and was the subject of a study to determine the capacity of wetlands to improve the chemical quality of such drainage. (Photograph by Katherine Walton-Day, U.S. Geological Survey.) 136 National Water Summary Wetland Resources: STATE SUMMARIES rfi^l 1 WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown ^^^1 Predominantly wetland Predominantly deepwater habitat 0 25 50 KILOMETERS PHYSIOGRAPHIC DIVISIONS PRECIPITATION -11 - Line of equal annual precipitation Interval, in inches, is variable. Figure 2. Wetland distribution in Colorado and physical and cfimatological features that control wetland distribution in the State. A, Dis- tribution of wetlands and deepwater habitats. B, Physiography. C, Annual precipitation. (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 1991. B, Physiographic divisions from Fenneman, 1946; landforms data from EROS Data Center. C, Petsch, 1986.) National Water Summary Wetland Resources: COLORADO 137 tioning riparian ecosystems. Water-control projects such as reser- voirs or irrigation canals, which reduce seasonal streamflow varia- tion and eliminate periodic flooding, can adversely affect many stream side-well and functions (Cooper, 1988). Evaporation generally is greatest in eastern Colorado (fig. 2D). Evaporation decreases with altitude and is least in the mountains. Local evaporation patterns can affect wetland development. For example, on the windward side of ridges above timberline, strong winds redistribute snow to the leeward side and increase evapora- tion (Windell and others, 1986). The result is a dry environment on the windward side, whereas on the leeward side, accumulated snow melts slowly and creates a moist environment conducive to devel- opment of alpine wetlands. In most of Colorado, evaporation exceeds precipitation annu- ally, and, except in mountainous areas, there is a net statewide an- nual moisture deficit that inhibits wetland formation. The moisture deficit prevents the formation of bogs, which are emergent wetlands that have organic soils and receive moisture only from precipita- tion. In mountainous areas, where there is sufficient moisture for bog formation, steep topography and shifting stream channels pre- vent their development (Cooper, 1986). Ground-water discharge from springs, shallow water tables, or both maintain wetlands in many areas of Colorado. The results of a study of wetlands in a river basin in the eastern plains indicated that most wetlands were along springfed streams that have perennial How in reaches 1-2 miles in length (Cooper and Cottrell, 1989). In the intermountain basins, ground water is an important determinant of wetland location. Wetlands in the San Luis Valley (fig. 2A ), an in- termountain basin, are hydrologically supported by springs or ground-water mounds that form during spring and summer runoff (Cooper and Severn, 1992). Climatic, topographic, and hydrologic characteristics differ among and sometimes within physiographic provinces. Colorado's diverse physiography results in diverse hydrologic settings for wet- land formation. In the Great Plains, wetlands occur in riparian zones of peren- nial streams, in oxbow lakes (abandoned stream meanders), in iso- lated depressions that have permanent or seasonal water supply, in playa lakes (primarily in the southern part of the region), and in association with reservoirs or channelized streams, rivers, and irri- gation ditches. EVAPORATION 40 Line of equal free-water-surface evaporation Interval, 5 inches In the Colorado Plateaus and Wyoming Basin, wetlands occur along perennial and intermittent streams, in oxbow lakes, around reservoirs, in springs and seeps, and where there is a shallow water table. Because of their semiarid to arid climate, these regions have a lower density and acreage of wetlands than does the rest of the State. As a result, the region's wetlands are disproportionately valu- able to wildlife. In the Rocky Mountains, wetlands form in two physio- graphically and climatically distinct settings: mountain valleys and intermountain basins. Mountain valleys generally are geologically young and, therefore, steep. The valleys have been shaped either by running water over their entire length or by glaciers at higher alti- tude and running water at lower altitude. Wetlands in mountain valleys occur in both glaciated and nonglaciated parts of the val- leys in locations from cliff faces to valley floors. Glaciation (fig. 2E ) in the alpine zone of some mountain valleys formed large cirque basins in which remnant glaciers or late-melting snow maintain spring, seep, and snowbed wetlands. Cirque lakes, or tarns, formed by glacial scouring, collect meltwater and attenuate downhill flow. Also in the alpine zone, ponds form in depressions behind slump- ing saturated soils or in depressions caused by the weight of ac- cumulated snow. Below cirque basins, glaciated, steep-sided, U- shaped valleys have broad, flat floors and relatively low-gradient streams. Wetlands form on saturated cliff faces, at the sloping floor near the sides of the valley, in oxbow lakes, in glacial kettle ponds, in depressions on the surface of glacial moraines, in lakes created by terminal or lateral moraines, in landslide-formed lakes, in or near seeps and springs, and in beaver ponds. In steep, V-shaped, non- glaciated parts of mountain valleys, wetlands occur as narrow ri- parian wetlands, in or near springs and seeps, and in beaver ponds (Windell and others, 1986). Intermountain basins, which were formed by tectonic forces, are filled by sediments derived from erosion of the surrounding mountains. The large, flat valleys are drained by low-gradient me- andering streams and rivers. Wetlands in the intermountain basins form along these streams and rivers, in natural and constructed impoundments, in oxbow lakes, and in areas having a shallow water table maintained by underlying aquifers, annual flooding, or imper- meable substrates (Windell and others, 1986). The San Luis Valley is an intermountain basin in southern Colorado. Throughout much of the valley, the water table is shal- CLACIATION Glacial extent during most recent glacial maximum Figure 2. Continued. Wetland distribution in Colorado and physical and climatological features that control wetland distribution in the State D, Annual free-water-surface evaporation. £, Extent of most recent glaciation. (Sources: D, Farnsworth and others, 1982. E, Mon- tagne, 1972.) 138 National Water Summary Wetland Resources: STATE SUMMARIES low or at land surface, creating large areas of wetlands that have diverse vegetation (Cooper and Severn, 1992). Wetlands in the val- ley provide habitat for resident and migratory waterfowl and enhance water quality. The valley hosts endangered whooping cranes dur- ing migration and has the State's largest concentration of wintering bald eagles (U.S. Fish and Wildlife Service, 1990). The State's largest National Wildlife Refuges, Alamosa and Monte Vista, are located there. Ground water is used to irrigate the valley and augment sur- face-water flow in the Rio Grande. Recently, developers have sought to export ground water from the valley to urban areas. The State Engineer's office estimated that this project could cause permanent water-table drawdown of several feet over large areas in the north- ern valley (Cooper and Severn, 1992). Such declines could decrease wetland acreage by reducing the area of saturated or inundated soil and the duration of inundation in emergent wetlands (Cooper and Severn, 1992). Redelfs (1980) reported that changes in irrigation practices since the early 1970's already have reduced wetland acre- age in the valley by 40 to 50 percent and have caused loss or drastic alteration of high-quality wetlands. The issue of new ground-water development illustrates the conflicts that occur frequently between development and wetland-conservation interests in the State. Studies of wetland function have been conducted in a few Colorado wetlands. Rovey and others (1986) concluded that veg- etation and water levels of wetlands in the Cross Creek area were dependent on stream hydrology. However, in another study of Cross Creek wetlands, Sundeen and others (1989) determined that the hydrology of those wetlands was largely independent of streams that flowed through them. Ruddy and Williams (1991) reached a simi- lar conclusion about wetlands in the Williams Fork. Cooper (1990), in a study of wetland vegetation in South Park, delineated stands of rare vegetation whose main range is in wetlands of boreal and arc- tic Canada and Alaska. A study of the water-quality function of a subalpine wetland in the upper Arkansas River basin (indicated that the wetland removed iron from a stream affected by acidic mine drainage that flowed through the wetland (Walton-Day, 1991). An upper-montane wetland has been intensively studied to determine the processes that caused elevated uranium concentrations (Owen, 1990), and reconnaissance work has been conducted in many other such wetlands (Owen and others, 1992). Although these investiga- tions of natural processes have added to what is known of Colorado's wetlands, the functions and values of the State's wetlands remain largely unstudied (Cooper and Severn, 1992). TRENDS The FWS has estimated that, from the 1780's to the 1980's, wetland area in Colorado decreased by 50 percent from about 2 million to about 1 million acres (Dahl, 1990). In agricultural areas, conversion to cropland, dewatering for irrigation purposes, and overgrazing by livestock contribute to wetland losses. In urban areas, wetland losses are due to encroachment by residential and commer- cial construction, channelization, dewatering for municipal and industrial purposes, and contamination from inadequately treated sewage and industrial waste. In other areas, losses have been caused by ski-resort development, transmountain water diversions, drain- age, river channelization, burning, clear cutting, mining and related activities that produce toxic acidic or alkaline drainage, peat mining, placer mining, water disposal, mine-tailing deposition, erosion and sedimentation, accidents such as drilling-mud spills or tailing-dam failures, sand and gravel mining, road and railroad construction, dams and reservoirs, and acidic precipitation (U.S. Fish and Wild- life Service, 1990, p. 9; Windell and others, 1986). Some land-use practices have created new wetlands or enlarged existing ones. Leaking ditches, uncapped flowing wells, and seeps and return flows associated with irrigation have increased wetland acreage or improved wetland habitat, notably in the San Luis Val- ley (Windell and others, 1986), but also in other regions of the State (Hopper, 1968; Rector and others, 1979). Gravel-pit construction also has increased wetland acreage, and gravel mining and agricul- tural activities are totally or partially responsible for two-thirds of the wetlands inventoried in the Boulder, Colo., area (Cooper, 1988). Reservoir construction has undoubtedly increased the acreage of lacustrine wetlands. CONSERVATION Many government agencies and private organizations partici- pate in wetlands conservation in Colorado. The most active agen- cies and organizations and some of their activities are listed in table 1. Federal wetland activities. Development activities in Colo- rado wetlands are regulated by several Federal statutory prohibi- tions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Harbors Act; the 1972 Clean Water Act and amendments; the 1985 Food Security Act; the 1990 Food, Agriculture, Conservation, and Trade Act; and the 1986 Emergency Wetlands Resources Act. Section 10 of the Rivers and Harbors Act gives the U.S. Army Corps of Engineers (Corps) authority to regulate certain activities in navigable waters. Regulated activities include diking, deepening, filling, excavating, and placing of structures. The related section 404 of the Clean Water Act is the most often-used Federal legislation protecting wetlands. Under section 404 provisions, the Corps issues permits regulating the discharge of dredged or fill material into wetlands. Permits are subject to review and possible veto by the U.S. Environmental Protection Agency (EPA), and the FWS has review and advisory roles. Section 401 of the Clean Water Act grants to States and eligible Indian Tribes the authority to approve, apply conditions to, or deny section 404 permit applications on the basis of a pro- posed activity's probable effects on the water quality of a wetland. Most farming, ranching, and silviculture activities are not sub- ject to section 404 regulation. However, the "Swampbuster" provi- sion of the 1985 Food Security Act and amendments in the 1990 Food, Agriculture, Conservation, and Trade Act discourage (through financial disincentives) the draining, filling, or other alteration of wetlands for agricultural use. The law allows exemptions from pen- alties in some cases, especially if the farmer agrees to restore the altered wetland or other wetlands that have been converted to agri- cultural use. The Wetlands Reserve Program of the 1990 Food, Agriculture, Conservation, and Trade Act authorizes the Federal Government to purchase conservation easements from landowners who agree to protect or restore wetlands. The Consolidated Farm Service Agency (formerly the Agricultural Stabilization and Con- servation Service) administers the Swampbuster provisions and Wet- lands Reserve Program. The National Resources Conservation Service (formerly the Soil Conservation Service) determines com- pliance with Swampbuster provisions and assists farmers in the iden- tification of wetlands and in the development of wetland protection, restoration, or creation plans. The 1986 Emergency Wetlands Resources Act encourages wetland protection through funding incentives. The act requires States to address wetland protection in their Statewide Comprehen- sive Outdoor Recreation Plans to qualify for Federal funding for State recreational land; the National Park Service provides guidance to States in developing the wetland component of their plans. State wetland activities. Although Colorado currently (1993) has no comprehensive wetlands-protection program, the State is assessing the need for a wetlands policy. Several State agencies actively participate in aspects of Federal programs, and some wet- lands are protected under State programs. The Water Quality Control Division of the Department of Health reviews section 404 permit applications to ensure compli- National Water Summary Wetland Resources: COLORADO 139 Table 1 . Selected wetland-related activities of government mil applications and some local land-use issues to assess potential agencies and private organizations in Colorado, 1993 adverse effects on wildlife. Also, the Division regulates construc- [Source: Classification of activities is generalized from information provided tion activities that affect streams and riparian areas, acquires wet- by agencies and organizations. , agency or organization participates in lands through sales of Federal duck-hunting permits, and conducts wetland-related activity;.... agency or organization does not participate in habitat-improvement projects on public and private lands. wetland-related activity. MAN, management; REG, regulation; R&C, res- . . . . / ^ Oi * , , . ,. toration and creation; LAN, land acquisition; R&D, research and data col- The activities of a few State agencies include restoration of lection; D&l. delineation and inventory] former wetlands or creation of new wetlands. The Department of _______________________________________ Highways uses best management practices to avoid or minimize ^ <b ^ -^ ^ \ disturbances to wetlands caused by highway maintenance and con- Agency or organization______________^ <& <$& -$ <^ <p struction. Unavoidable damage to wetlands is mitigated through FEDERAL wetland restoration or creation. The Department has data-collec- Department of Agriculture tion and monitoring programs to facilitate compliance with section Consolidated Farm Service Agency........................... ... .. .. .. 404 permitting requirements and to assess the effectiveness of miti- Forest Service................................................................. gation projects. The Division of Minerals and Geology creates Natural Resources Conservation Service ................ . . . . wetlands to treat water from abandoned mines. The State Forest Drm7cZ?oDf Sneers............................................. ...... Service helPs Private landowners develop or augment wetlands. Military reservations .......................................1........... County and local wetland activities. Most regulation of de- Department of the Interior velopment activities in Colorado's wetlands is accomplished through Bureau of Land Management...................................... . . Federal and State laws. However, Eagle and Pi tkin Counties (which Bureau of Reclamation ................................................. contain the towns of Vail and Aspen, respectively) and the cities of Fish and Wildlife Service.............................................. . . . . Boulder, Broomfield, Fort Collins, and Greenwood Village have Geological Survey.......................................................... , . ' . , ,. , , National Biological Service adopted their own ordinances or guidelines to protect wetlands or National Park Service ................................................... ...... to mitigate unavoidable wetland losses. Environmental Protection Agency.................................. . . Private wetland activities. Ducks Unlimited owns more than Native American Tribes 2,200 acres of wetlands statewide (Ducks Unlimited, 1992). The Southern Ute ................................................................... ... . . Nature Conservancy owns about 1.600 acres (A.T. Carpenter, The Ute Mountain................................................................... . . ^ T J . inr\^\ /^u «.- STATE Nature Conservancy, written commun., 1992). Other organizations Department of Agriculture ............................................... that participate in wetland-protection activities in the State include Department of Health the Colorado Native Plant Society, the Colorado Riparian Associa- Hazardous Materials and Waste tior, 5 the Colorado Wildlife Federation, the Grand Canyon Trust, WatTSit* Cortrol Commission""""""""""""""" * High Country Caen's Alliance, the Sierra Club, Colorado Trout Walel Quality Control Sm^II^IIIl I . Unlimited, the Colorado Cattleman's Association, and Colorado Department of Highways.................................................. . . . Earth First! (Chew, 1991). Department of Natural Resources Division of Parks and Outdoor Recreation . Colorado Natural Areas Program........................... . ..... References Cited Division of Wildlife ......................................................... . . ... Land Commissioners...................................................... . Bureau of Land Management, 1991, Riparian-wetlands initiative for the Division of Minerals and Geology............................... ... 1990's: Bureau of Land Management Report BLM/WO/GI-91/ State Forest Service.......................................................... 001+4340,50 p. SOME COUNTY AND LOCAL GOVERNMENTS ............. . Chew, M.K., 1991, Bank balance Managing Colorado's riparian areas: PRIVATE ORGANIZATIONS Fort Collins, Colorado State University Cooperative Extension Bul- Ducks Unlimited .................................................................. ..... letin 553A, 49 p. The Nature Conservancy.................................................. ........ Colorado Department of Natural Resources, 1992, Statewide comprehen- sive outdoor recreation plan, draft of section IX, SCORP wetlands amendment: Denver, Colorado Department of Natural Resources, Division of Parks and Outdoor Recreation, 8 p. ance with State water-quality laws. A permit is not issued by the Cooper, D.J., 1986, Ecological studies of wetland vegetation, Cross Creek Corps without certification of such compliance by the Division. Valley, Holy Cross Wilderness, Sawatch Range, Colorado: Boulder, Pursuant to section 305(b) of the Clean Water Act, the Division Colo., Holy Cross Wilderness Defense Fund. Technical Report 2,25 p. submits to the EPA and the U.S. Congress a biennial assessment of [Available from Holy Cross Wilderness Defense Fund. 1130 Alpine, the State's surface-water quality, including that of wetlands. Boulder, CO 80304.] The Colorado Department of Natural Resources has diverse 1988, Advance identification of wetlands in the city of Boulder Corn- wetland responsibilities. The Department's Division of Parks and prehensive Planning Area: Boulder, Colo., Boulder Planning Depart- Outdoor Recreation develops the Statewide Comprehensive Outdoor __"^ EPco,ogical studl£s in South Park Colorado-Classification, Recreation Plan. Pursuant to the requirements of the Emergency functional analysis, rare species inventory, and the effects of remov- Wetlands Resources Act of 1986, the most recent plan (Colorado ing irrigation (Contract report prepared for the U.S. Environmental Department of Natural Resources, 1992) prioritizes wetland protec- Protection Agency, Region VIII, and the Park County Commission): tion by wetland type and function. The Division's Colorado Natural Fairplay, Colo., Park County Commission, 94 p. [Available from Li- Areas Program identifies and seeks protection for unique natural brarian, U.S. Geological Survey, Colorado District, Box 25046, MS areas in the State. A "natural area" designation results in a main- 415, Denver Federal Center, Bldg. 53, Denver, CO 80225.] tenance agreement among landowners, the Colorado Natural Areas Cooper, D.J., and Cottrell, T.R., 1989, An ecological characterization and Program, and other interested parties. By 1992, about 5,000 acres funct,io0nal evaluation of wetlands in the Cherry Creek Basin-Cherry f .., , j + A * i /Tr^i /^ i j Creek Reservoir upstream to Franktown (Contract report prepared for of wetland were in designa ed natural areas (JJ. Coles, Colorado ^ y s Envinjmjental Protection Agency, Region VIII, and the city Natural Areas Program, oral commun., 1992). The Colorado Natu- of Greenwood village): Golden, Colorado School of Mines, 57 p. ral Areas Program has compiled inventories of plants and animals Cooper, D.J., and Severn, Craig, 1992, Wetlands of the San Luis Valley, and plant associations of special concern in environments that in- Colorado An ecological study and analysis of the hydrologic regime, elude wetlands. The Division of Wildlife reviews section 404 per- soil chemistry, vegetation and the potential effects of a water table 140 National Water Summary Wetland Resources: STATE SUMMARIES drawdown (Contract report prepared for the State of Colorado Divi- sion of Wildlife, U.S. Fish and Wildlife Service, and Rio Grande Water Conservation District [Colo.]): Denver, Colorado Division of Wild- life, 158 p. [Available from Librarian, U.S. Geological Survey, Colo- rado District, Box 25046, MS 415, Denver Federal Center, Bldg. 53, Denver, CO 80225.] Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Dahl, T.E., 1990, Wetlands Losses in the United States, 1780's to 1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 13 p. Ducks Unlimited, 1992, Homework Stockpiling wildlife does not work, preserving the habitat resource does!: Wild Dawn, v. 2, no. 4, p. 6-7. Farnsworth, R.K., Thompson, E.S., and Peck, E.L., 1982, Evaporation at- las for the contiguous 48 United States: National Oceanic and Atmo- spheric Administration Technical Report NWS 33, 27 p. Fenneman, N.M., 1946, Physical divisions of the United States: Washing- ton, D.C., U.S. Geological Survey special map, scale 1:7,000,000. Hopper, R.M., 1968, Wetlands of Colorado: Colorado Department of Game, Fish, and Parks Technical Publication 22, 89 p. Montagne, J.M., 1972, Glaciation during the Wisconsin stage, in Rocky Mountain Association of Geologists, 1972, Geologic Atlas of the Rocky Mountain Region: Denver, Hirschfeld Press, p. 259. Owen, D.E. (chair), 1990, Session G Multidisciplinary studies of a moun- tain fen, Society of Wetland Scientists, llth annual meeting, Final Program, Breckenridge, Colo., June 4-6, 1990: Society of Wetland Scientists, p. 54, 56-58, 61, 70. Owen, D.E, Otton, J.K., Hills, F.A., and Schumann, R.R., 1992, Uranium and other elements in Colorado Rocky Mountain wetlands A recon- naissance study: U.S. Geological Survey Bulletin 1992, 33 p. Petsch, H.E., Jr., 1986, Colorado surface-water resources, in U.S Geologi- cal Survey, National water summary 1985 Hydrologic events and surface-water resources: U.S. Geological Survey Water-Supply Paper 2300, p. 167-174. Rector, C.D., Mustard, E.W, and Windell, J.T., 1979, Lower Gunnison Basin wetland inventory and evaluation: U.S. Soil Conservation Service, Bureau of Reclamation, Colorado Division of Wildlife, and Univer- sity of Colorado cooperative publication, 90 p. Redelfs, A.E., 1980, Wetlands values and losses in the United States: Stillwater, Oklahoma State University, M.S. thesis, 144 p. Rovey, E.W., Kraeger-Rovey, Catherine, and Cooper, D.J., 1986, Hydrologi- cal and ecological processes in a Colorado Rocky Mountain wetland, in Kane, D.L., ed., Proceedings of the Symposium on Cold Regions Hydrology, Fairbanks, Alaska, 1986: Bethesda, Md., American Water Resources Association, p. 93-100. Ruddy, B.C., and Williams, R.S., Jr., 1991, Hydrologic relations between streamflow and subalpine wetlands in Grand County, Colorado: U.S. Geological Survey Water-Resources Investigations Report 90-4129, 53 p. Sundeen, K.D., Leaf, C.F., and Bostrom, G.M., 1989, Hydrologic functions of sub-alpine wetlands in Colorado, in Fisk, D.W., ed., Proceedings of the Symposium on Wetlands Concerns and Successes, Tampa, Fla., September 17-22, 1989: Bethesda, Md., American Water Re- sources Association, p. 401-413. U.S. Fish and Wildlife Service, 1955, Wetlands inventory Colorado: Al- buquerque, N. Mex., U.S. Fish and Wildlife Service, Report by the Office of River Basin Studies, 19 p., 16 pis. ____1960, Inventory of permanent water areas of importance to water- fowl in the state of Colorado: Albuquerque, N. Mex., U.S. Fish and Wildlife Service and Colorado Department of Game and Fish coop- erative publication, 9 p. .1990, Regional wetlands concept plan Emergency wetlands re- sources act: Lakewood, Colo., U.S. Fish and Wildlife Service, 90 p., 4 apps. Walton-Day, Katherine, 1991, Hydrology and geochemistry of a natural wetland affected by acid mine drainage, St. Kevin Gulch, Lake County, Colorado: Golden, Colorado School of Mines, Ph.D. dissertation #T- 4033, 299 p. Windell, J.T., Willard, B.E., Cooper, D.J., and others, 1986, An ecological characterization of Rocky Mountain montane and subalpine wetlands: U.S. Fish and Wildlife Service Biological Report 86(11), 298 p. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Survey, Building 53, Box 25046, Mail Stop 415, Denver Federal Center, Denver, CO 80225; Regional Wetland Coordinator, U.S. Fish and Wildlife Service, Fish and Wildlife Enhancement, P.O. Box 25486, Denver Federal Center, Denver, CO 80225 Prepared by Katherine Walton-Day, U.S. Geological Survey U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources 141 Connecticut Wetland Resources ^Connecticut's diverse wetlands are valued for the environmental and economic benefits they provide, such as wildlife habitat, water- quality improvement, flood and erosion control, recreation, hunt- ing, trapping, and esthetic beauty. Wetlands provide food, shelter, and breeding and nursery grounds for fish, shellfish, birds, and other wildlife, many of whose populations are threatened or endangered. The quality of water that passes through wetlands is typically en- hanced by physical and biochemical processes. Undeveloped flood- plain wetlands along the Connecticut River and other rivers in the State provide natural storage that helps regulate floodwaters. Be- cause wetlands are valuable to the people of Connecticut, the Fed- eral and State governments own and protect several wetlands, such as Robbins Swamp (fig. 1). TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deep- water habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and oth- ers, 1979). The distribution of wetlands and deepwater habitats in Connecticut is shown in figure 2A\ only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Connecti- cut are described below. System Palustrine. Lacustrine Wetland description Nontidal and tidal-freshwater wetlands in which vegetation is predominantly trees (forested wet- lands); shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted herba- ceous plants (persistent- and nonpersistent- emergent wetlands); or submersed and (or) floating plants (aquatic beds). Also, intermit- tently to permanently flooded open-water bod- ies of less than 20 acres in which water is less than 6.6 feet deep. Nontidal and tidal-freshwater wetlands within an intermittently to permanently flooded lake or reservoir larger than 20 acres and (or) deeper than 6.6 feet. Vegetation, when present, is pre- dominantly nonpersistent emergent plants {non- persistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds), or both. Nontidal and tidal-freshwater wetlands within a channel. Vegetation, when present, is same as in the Lacustrine System. Tidal wetlands in low-wave-energy environments where the salinity of the water is greater than 0.5 part per thousand (ppt) and is variable owing to evaporation and the mixing of seawater and freshwater. According to a survey conducted in the early 1980's by the Connecticut Department of Environmental Protection on contract Riverine... Estuarine, to the FWS National Wetland Inventory (Metzler and Tiner, 1992), wetlands covered about 172,500 acres, or about 5 percent, of Con- necticut at that time. Wetlands were defined on the basis of aerial- photo interpretation of visible vegetation types and hydrology. Evalu- ations of the accuracy of the National Wetland Inventory maps for Vermont and Massachusetts, which were produced using the same techniques as for the Connecticut inventory, indicated that the l:24,000-scale maps had accuracies of 91 percent and greater than 95 percent, respectively, in those States (Metzler and Tiner, 1992). Wetland area and density are greatest in the eastern part of the State (fig. 2B). Palustrine wetlands are by far the most common wetland type in the State, followed by estuarine wetlands (fig. 2C); together, they constitute about 99 percent, by area, of the State's wetlands. The combined area of lacustrine and riverine wetlands makes up the remaining 1 percent of wetland acreage. A description of Connecticut's most common wetland types follows. Palustrine wetlands. Vegetated palustrine wetlands in Con- necticut include ponds and shallow lakes in which the dominant vegetation is floating or submersed (aquatic-bed wetlands); fresh- water marshes, fens, and bogs dominated by herbaceous plants (emergent wetlands); and bogs and swamps dominated by shrubs or trees (scrub-shrub or forested wetlands). Palustrine forested wetlands constitute 54 percent of the State's wetlands (Metzler and Tiner, 1992) and consist primarily of red maple swamps with some evergreen forested wetlands. Red maple grows in most inland wetlands because it tolerates a wide range of flooding and soil-satu- ration conditions. The vegetation found with red maple, in the un- derstory and intermixed or codominating in the canopy, differs ac- cording to nutrient conditions and water regime. Evergreen forested wetlands are commonly vegetated by Atlantic white cedar in east- ern Connecticut (Metzler and Tiner, 1992) and hemlock or black spruce in western Connecticut (Messier, 1980). Lacustrine and riverine wetlands. Although present through- out the State, lacustrine and riverine wetlands comprise only a small percentage of Connecticut's wetland area. These freshwater wetlands generally are restricted to the channel or the shallow zone between the shore and deepwater habitat. If vegetated, they have only aquatic- bed or nonpersistent emergent vegetation. Riverine wetlands are most abundant in the freshwater tidal areas of the Connecticut and Housatonic River (Metzler and Tiner, 1992). Shallow wetlands ad- Figure 1. Robbins Swamp, near Canaan. This 1,000-acre forested wetland is the largest inland wetland in Connecticut. The wetland provides wild- life habitat, outdoor recreation, and other benefits. Parts are owned by the State and The Nature Conserv- ancy. (Photograph by Ellen M. Ramsey, The Nature Conservancy.) 142 National Water Summary Wetland Resources: STATE SUMMARIES jacent to rivers or lakes are classified as palustrine wetlands if there is persistent emergent vegetation present. Estuarine wetlands. Estuarine wetlands consist of salt and brackish marshes (emergent and scrub-shrub wetlands) that have developed in protected coves and embayments along the coast and estuaries adjacent to Long Island Sound. Sparsely vegetated estua- rine flats and beaches, alternately flooded by tide or exposed to air, also are present. HYDROLOGIC SETTING Wetlands occur in geologic, topographic, and hydrologic set- tings lhat enhance the accumulation and retention of ground water, surface water, or both for extended periods of time. Hydrologic proc- esses are the primary factors determining the existence of wetlands; even if the geologic and topographic settings are favorable for wet- land formation, unfavorable hydrologic conditions can inhibit wet- v ,/ . . V \"Tl>" Jf 'i V\-- /\J / 4 1* / >*'7 f '«* -» . if.' 'M^ ' / * Vd|T)0f> ~^ Sniar[ B ^^ Fish and Wildlife Area ' f j-* '% f *«ft' ' y- 0 ,*/ i , s i - NWR 5 10 1 «i MM F"5 ° 5 10 ^ KILOMETERS WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are rot shown ^^H Predominantly wetland Predominantly deepwater habitat WETLAND ACREAGE AND DENSITY, BY COUNTY 28,702 Acres of wetland in county 8.6 Percent of county covered by wetland Riverine and lacustrine wetlands 1 percent (1,929 acres) Estuarine wetlands percent (18,828 acres) Palustrine wetlands 88 percent (151,791 acres) RELATIVE AND ACTUAL ACREAGE OF WETLANDS TYPES IN CONNECTICUT PHYSIOGRAPHIC DIVISIONS New England Province A. Taconic Section B. Connecticut Valley Lowland C. New England Upland Section D. Seaboard Lowland Section Figure 2. Wetland distribution in Connecticut and physical features that control wetland distribution in the State. A, Distribution of wetlands and deepwater habitats. B, Wetland acreage and density, by county. C, Relative and actual acreage of wetland types in the early 1980's for Connecticut. D, Physiography. (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 1991. B and C, Data from Metzler and Tiner, 1992. D, Physiographic divisions from Fenneman, 1938; landforms data from EROS Data Center.) National Water Summary Wetland Resources: CONNECTICUT 143 land formation (Winter, 1988). On an annual basis, precipitation exceeds evapotranspiration losses in Connecticut, resulting in an annual moisture surplus. Hydrology, therefore, favors the formation of wetlands throughout the State, and wetland location is determined primarily by geologic and topographic controls. Connecticut's physical features created by geologic forces over millions of years, erosion and deposition from recent glacia- tion, and human activities combined with present-day hydrologic conditions, determine the distribution of wetlands in the State. Con- necticut can be divided into four physiographic divisions based upon general topographic relief: the Taconic, the Connecticut Valley Low- land, the New England Upland, and the Seaboard Lowland Sections of the New England Province (fig. 2D). Topographic relief gener- ally increases from the southeast to northwest corners of the State. Major lowland areas include the Seaboard Lowland, Connecticut Valley Lowland, and, in the New England Upland and Taconic Sec- tions, deep valleys formed of weathered, calcareous bedrock. Con- necticut was completely covered by ice during the last glaciation; the ice margin reached its maximum extent at Long Island, New York. Glaciation did little to change the preglacial, fluvially eroded bedrock topography except for locally deepening bedrock hollows and river valleys (Schafer and Hartshorn, 1965). Large quantities of sediment were produced and deposited over bedrock throughout the State. This sediment either was deposited on upland hilltops and slopes as till or was eroded and reworked by glacial meltwater and deposited as stratified drift (sorted and layered glacial sediments). Stratified drift was deposited in topographically low areas major lowlands such as the Connecticut Valley Lowland and in stream and river valleys throughout the State. Many wetlands in Connecticut occur in the depressions, deepened valleys, and lowlands in which stratified drift was deposited. Inland wetlands. During deglaciation, a series of large gla- cial lakes occupied the Connecticut Valley Lowland, and smaller lakes occurred along many river valleys throughout the State (Schafer and Hartshorn, 1965). Extensive areas of flat, slowly per- meable stratified drift were deposited on the bottom of these lakes. The generally low relief and poorly permeable substrate of these areas retain surface water or slow its drainage, leading to the for- mation and maintenance of wetlands. Owing to the low slope of these areas, small drainage obstructions can form large wetlands. Sources of water can be ground-water discharge, surface runoff, or direct precipitation. Wetlands occur in small and large valleys throughout Connecti- cut. Some wetlands occupy the depressions, or kettles, left by melt- ing ice blocks in stratified drift. Wetlands also have formed in areas modified by the recent erosion and deposition of rivers in aban- doned river channels, behind levees and overbank sediments adja- cent to rivers, and in backswamp areas. In the New England Up- land and Taconic Sections, the hilly topography of upland areas of till or bedrock generally does not retain surface runoff. Wetlands form primarily in isolated depressions where surface runoff and ground-water discharge collect. The depressions may have no out- flow or have drainage controlled by bedrock sills, stratified drift, beaver dams, or manmade structures. Seepage wetlands may form where the water table intersects the land surface, such as on con- cave slopes and at breaks in slope; however, the wetlands are pe- rennial only if ground-water discharge is perennial (Winter, 1988). The position of a wetland in the landscape determines the nutrient status and vegetative characteristics of the wetland (Damman and French, 1987). Water that has moved through soil and subsurface materials carries nutrients that encourage plant growth. Wetlands in upland till and bedrock depressions are primarily areas of discharge from nutrient-poor, local ground-water flow systems, whereas wetlands in lowland stratified-drift valleys receive dis- charge from more nutrient-enriched ground-water flow systems (Winter, 1988). Wetlands in the New England Upland and Taconic Sections, which are underlain by metamorphosed calcareous rocks, are distinct from those in the more widespread acidic bedrock ar- eas of the State. Soils and ground water derived from calcareous rocks are rich in nutrients, resulting in wetlands such as Robbins Swamp that support a lush and diverse flora (Dowhan and Craig, 1976). As vegetation became established after glacial retreat and de- veloped in response to the warming climate, open-water areas filled with sediment or organic matter to become wetlands or remained lakes with wetlands fringing open water. Studies of upland wetlands in northeastern Connecticut have shown that wetlands have devel- oped over many divergent paths in the time since deglaciation (Thorson, 1990, 1992; Thorson and Harris, 1991). Postsettlement agricultural and industrial practices, rather than natural ecological factors, determined the present-day character of all previously existing wetlands. In addition, many wetlands were formed since settlement as a result of the effects of colonial land use and the con- struction of cattle-watering sites, ice ponds, and mill ponds for water-powered industries. Tidal wetlands. Wetlands in coastal areas of Connecticut have water-level fluctuations that are driven largely by ocean tides. Tidal wetlands form a continuum from estuarine to tidal riverine to palustrine wetlands. The effects of wave energy and salinity on the wetlands diminish along this continuum, although not necessarily at the same rate. Tidal effects are present in the Connecticut River as far as Windsor Locks near the Massachusetts border, whereas wetlands have graded from salt and brackish to freshwater before reaching Hartford. Tidal wetlands receive freshwater input from upland areas through ground-water discharge, stream overflow, and hillslope runoff. Regional ground-water discharge is greatest near the break in slope between upland and coastal areas, and interme- diate and local ground-water flow systems increase in importance in low areas (Winter, 1988). Floodwater resulting from high tides or stormflows may be temporarily stored on the wetland surface. The drainage of floodwater and hillslope runoff from the wetland surface is slowed by the low slope of coastal areas. Major areas of tidal wetlands are shown along major portions of the Housatonic, Quinnipiac, and Connecticut Rivers in figure 2A. The major factors affecting the development and persistence of tidal wetlands are the postglacial rise of sea level relative to the land, the tidal regime, the supply of sediments to the wetland, and the ability of plants to survive submergence by saltwater (Redfield, 1972). Unless the submergence of tidal wetlands by rising sea level is counteracted by the vertical accretion of the wetland by sediment deposition and plant accumulation, the wetland will drown and be- come a deepwater habitat. When the glaciers melted, the sea rose and encroached upon land, inundating many stream and river val- leys to form estuaries. Tidal wetlands either have migrated inland along estuaries, river valleys, and coastal slopes or the wetlands have been completely inundated. Salt-marsh peats, as much as 12.5 feet thick, overlie freshwater peats in parts of the Pataguanset River val- ley and indicate the change in wetland type in response to chang- ing sea levels 4,000 years ago (Orson and others, 1987). Presently, tidal wetlands exist in a narrow setting between rising sea level and expanding coastal development. As sea level continues to rise, the migration of these wetlands inland is hindered by historic alteration of coastal-margin wetlands and by present development. TRENDS The FWS has estimated that Connecticut lost 74 percent of its original wetlands over the 200-year period between the 1780's and the 1980's (Dahl, 1990). The FWS estimate is based on the assump- tion that Connecticut originally had about 670,000 acres of wetlands. However, Metzler and Tiner (1992) discuss some of the limitations of the methods used in the FWS inventory to estimate predevelopment 144 National Water Summary Wetland Resources: STATE SUMMARIES and recent wetland acreage when applied to Connecticut. They be- lieve that statewide wetland losses of one-third to one-half are more realistic (Metzler and Tiner, 1992). The Connecticut Department of Environmental Protection estimates losses of 40 to 50 percent for freshwater wetlands and 65 percent for coastal wetlands. Some tidal wetlands have been created through the effects of human activities. Barske (1988) describes the development of 700 acres of salt marsh at the mouth of the Housatonic River through the accumulation of sediment, the result of upstream deforestation and other activities. Often, however, human activities lead to the degradation of tidal wetlands. The elimination or restriction of tidal flow commonly results in reduced salinity, lowered water tables, subsidence of wetlands peats, and conversion of wetland vegetation to less salt-tolerant species (Roman and others, 1984; Rozsa, 1988). Roman and others (1984) estimate that 10 percent of Connecticut's salt marshes are subject to tidal-flow restriction. Loss of upstream freshwater wetlands, separation of watercourses and remaining up- stream wetlands from downstream areas by a railroad right-of-way, and loss of downstream tidal marshes have all contributed to a re- duction of productivity in Alewife Cove, an estuary on Long Island Sound (Welsh and others, 1976). Several degraded coastal wetlands in Connecticut are the site of restoration projects. The U.S. Army Corps of Engineers (Corps), in cooperation with the Connecticut Department of Environmental Protection, is working to identify and restore salt marshes that have been degraded as a result of tidal-flow restriction. CONSERVATION Many government agencies and private organizations partici- pate in wetland conservation in Connecticut. The most active agen- cies and organizations and some of their activities are listed in table 1. Table 1 . Selected wetland-related activities of government agencies and private organizations in Connecticut, 1993 [Source: Classification of activities is generalized from information provided by agencies and organizations. , agency or organization participates in wetland-related activity;.. , agency or organization does not participate in wetland-related activity. MAN, management; REG, regulation; R&C, resto- ration and creation; LAN, land acquisition; R&D, research and data collec- tion; D&l, delineation and inventory] Agency or organization v FEDERAL Department of Agriculture Consolidated Farm Service Agency......................... Forest Service ............................................................... Natural Resources Conservation Service .............. Department of Commerce National Oceanic and Atmospheric Administration ...................................... Department of Defense Army Corps of Engineers ............................................ Military reservations................................................... Department of the Interior Fish and Wildlife Service ............................................ National Biological Service ....................................... Environmental Protection Agency................................ STATE Department of Environmental Protection .................. Department of Transportation...................................... University of Connecticut.............................................. TOWN AND CITY CONSERVATION COMMISSIONS PRIVATE ORGANIZATIONS Connecticut Audubon Society...................................... Ducks Unlimited............................................................... The Nature Conservancy............................................... Federal wetland activities. Development activities in Con- necticut wetlands are regulated by several Federal statutory prohi- bitions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Harbors Act; the 1972 Clean Water Act and amendments; the 1985 Food Security Act; the 1990 Food, Agriculture, Conservation, and Trade Act; the 1986 Emergency Wetlands Resources Act; and the 1972 Coastal Zone Management Act. Section 10 of the Rivers and Harbors Act gives the Corps au- thority to regulate certain activities in navigable waters. Regulated activities include diking, deepening, filling, excavating, and plac- ing of structures. The related section 404 of the Clean Water Act is the most often-used Federal legislation protecting wetlands. Under section 404 provisions, the Corps issues permits regulating the dis- charge of dredged or fill material into wetlands. Permits are sub- ject to review and possible veto by the U.S. Environmental Protec- tion Agency, and the FWS has review and advisory roles. Section 401 of the Clean Water Act grants to States and eligible Indian Tribes the authority to approve, apply conditions to, or deny section 404 permit applications on the basis of a proposed activity's probable effects on the water quality of a wetland. Most farming, ranching, and silviculture activities are not sub- ject to section 404 regulation. However, the "Swampbuster" provi- sion of the 1985 Food Security Act and amendments in the 1990 Food, Agriculture, Conservation, and Trade Act discourage (through financial disincentives) the draining, filling, or other alteration of wetlands for agricultural use. The law allows exemptions from pen- alties in some cases, especially if the farmer agrees to restore the altered wetland or other wetlands that have been converted to agri- cultural use. The Wetlands Reserve Program of the 1990 Food, Agriculture, Conservation, and Trade Act authorizes the Federal Government to purchase conservation easements from landowners who agree to protect or restore wetlands. The Consolidated Farm Service Agency (formerly the Agricultural Stabilization and Con- servation Service) administers the Swampbuster provisions and Wet- lands Reserve Program. The Natural Resources Conservation Service (formerly the Soil Conservation Service) determines com- pliance with Swampbuster provisions and assists farmers in the iden- tification of wetlands and in the development of wetland protection, restoration, or creation plans. The 1986 Emergency Wetlands Resources Act and the 1972 Coastal Zone Management Act and amendments encourage wetland protection through funding incentives. The Emergency Wetland Resources Act requires States to address wetland protection in their Statewide Comprehensive Outdoor Recreation Plans to qualify for Federal funding for State recreational land; the National Park Ser- vice (NFS) provides guidance to States in developing the wetland component of their plans. Coastal States that adopt coastal-zone management programs and plans approved by the National Oceanic and Atmospheric Administration are eligible for Federal funding and technical assistance through the Coastal Zone Management Act. Federal agencies are responsible for the proper management of wetlands on public lands under their jurisdiction. The FWS pro- tects and manages wetlands in two National Wildlife Refuges the Stewart B. McKinney National Wildlife Refuge and the Salt Meadow National Wildlife Refuge. The Corps manages and conserves for- ests, water, fish, wildlife, wetlands, and recreation areas for mul- tiple uses at dams, reservoirs, and parks located throughout the State. State wetland activities. Tidal wetlands are protected under the Tidal Wetlands Act of 1969 and the Coastal Management Act of 1979. Activities in tidal wetlands are regulated at the State level with exemptions for mosquito control, conservation, navigation, and emergency activities. Tidal wetlands are defined by the State as areas that border or lie beneath tidal waters and that contain certain plant species. About 15,000 acres of tidal salt marsh and 7,000 acres of National Water Summary Wetland Resources: CONNECTICUT 145 brackish and freshwater tidal wetlands are regulated under this statute (Lefor and Tiner, 1972). Nontidal freshwater wetlands are protected under the Inland Wetlands and Watercourses Act of 1972. Inland wetlands are regu- lated according to State standards by local inland wetlands and watercourses commissions. Permits are required for all activities within wetlands with exemptions for agricultural activities, construc- tion and maintenance of water-supply systems, certain conserva- tion and recreation uses, and the enjoyment and maintenance of residential property. Inland wetlands are defined by soil type poorly drained, very poorly drained, flood-plain, or alluvial soils as delineated by the National Cooperative Soil Survey. Rivers, streams, waterways, and other natural and artificial water bodies are regulated under this statute as watercourses. On the basis of the State's wetland definition, 15 to 20 percent of Connecticut's land is subject to regulation as inland wetlands (Metzler and Tiner, 1992). Under section 401 of the Federal Clean Water Act, any activ- ity that results in a discharge, including that of fill into wetlands or State waters that requires a federal permit, must also obtain a sec- tion 401 water-quality certification stating that the activity will not violate State surface-water-quality standards. Many activities ex- empted under the Inland Wetlands and Watercourses Act are in the Department of Environmental Protection's jurisdiction under the section 401 certification program; however, normal maintenance and improvement of agricultural lands remain exempt from State and Federal authority. Use of the antidegradation provisions of State surface-water-quality standards on wetlands provides enhanced wetland protection. Antidegradation provisions provide for the protection of existing wetland functions and the level of water quality necessary to maintain and protect those functions. No degradation is allowed in areas designated as "outstanding national resource waters," such as National Wildlife Refuges, National Parks, State parks, wildlife areas, and other areas of ecological significance. The Water Resources Division of the Department of Environmental Pro- tection is responsible for section 401 certifications in Connecticut. The Department of Environmental Protection is the primary environmental and conservation agency in Connecticut. The Depart- ment owns more wetland acreage in Connecticut than does the Fed- eral Government (Metzler and Tiner, 1992). Numerous wetlands are protected in State parks, State forests, and wildlife-management areas throughout the State. Chester Cedar Swamp and Pachaug Great Meadows are partly State-owned wetlands and are designated as National Natural Landmarks by the NFS. The State owns significant portions of wetlands at Robbins Swamp, Durham Meadows, Barn Island Fish and Wildlife Areas, and Hammonasset State Park (Metzler and Tiner, 1992). Wetlands are acquired through the Rec- reation and Natural Heritage Act and sale of the new Connecticut Waterfowl Hunting Stamp. Funds derived from the stamp will be used solely for wetland acquisition or improvements. Development projects that cause unavoidable wetlands degra- dation or loss are required to mitigate or compensate for wetland loss by replacing or providing a substitute wetland resource. The Connecticut State Department of Transportation has been involved in wetlands creation and mitigation projects as a way to offset the long-term effects of highway construction. Wetlands, created and restored as a part of the design, permit, and construction .process, have provided lost wetland functions with varying success (Butts, 1988). The Department of Transportation has acquired about 200 acres of wetlands in compensation for wetlands lost through devel- opment projects; most of this land has remained under the Department's management. The Department provides funds for wetland-related research primarily at the University of Connecti- cut. Local wetland activities. Inland wetland and watercourse commissions and coastal-area zoning and planning commissions are responsible for planning and regulating wetland-related activities at the town or municipal level. Inland wetland and watercourse com- missions regulate activities through permitting under the Inland Wetland and Watercourses Act. Coastal-area zoning and planning commissions balance development and the preservation of environ- mental values in coastal areas under the Coastal Management Act. The act provides commissions with planning, research, and permit- ting authority. Education, training, support, and final authority are provided to commissions by the Department of Environmental Protection's Wetland Program. Private wetland activities. Private organizations in Connecti- cut are active in land acquisition and management, research, edu- cation, and policy review and planning. The Nature Conservancy protects about 1,800 acres of wetlands within the 9,000 acres of land under its ownership. Ducks Unlimited provides technical and finan- cial assistance to Federal and State agencies in order to protect waterfowl habitat in Connecticut. References Cited Barske, Philip, 1988, Man and nature Willing or unwilling partners, in Lefor, M.W., and Kennard, W.C., eds., Proceedings of the 4th Wet- lands Conference, November 15, 1986: University of Connecticut Institute of Water Resources Report 34, p. 91-99. Butts, M.P., 1988, Status of wetland creation/mitigation projects on State highway projects in Connecticut, in Lefor, M.W, and Kennard, W.C., eds., Proceedings of the 4th Wetlands Conference, November 15,1986: University of Connecticut Institute of Water Resources Report 34, p. 13-18. Cowardin, L.M., Carter, V., Golet, EC., and LaRoe, E.T., 1979, Classifica- tion of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Dahl, T.E., 1990, Wetlands Losses in the United States, 1780's to 1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 13 p. Damman, A.W.H., and French, T.W, 1987, The ecology of peat bogs of the glaciated northeastern United States A community profile: U.S. Fish and Wildlife Service Biological Report 85(7.16), 100 p. Dowhan, J.J., and Craig, R.J., 1976, Rare and endangered species of Con- necticut and their habitats: Connecticut Geological and Natural His- tory Survey Report of Investigations no. 6, 137 p. Fenneman, N.M., 1938, Physiography of Eastern United States: New "York, McGraw-Hill, 714 p. Lefor, M.W, and Tiner, R.W, 1972, Tidal wetlands survey of the State of Connecticut Report of the consultant biologists for the period De- cember 22,1969 to June 30,1972: Storrs, Biological Sciences Group, University of Connecticut, 113 p. Messier, S.N., 1980, The plant communities of the acid wetlands of north- western Connecticut: Storrs, University of Connecticut, M.S. thesis, 98 p. Metzler, K.J., and Tiner, R.W., 1992, Wetlands of Connecticut: State Geo- logical and Natural History Survey of Connecticut Report of Investi- gations no. 13, 115 p. Orson, R.A., Warren, R.S., and Niering, W.A., 1987, Development of a tidal marsh in a New England river valley: Estuaries, v. 10, p. 20-27. Redfield, A.C., 1972, Development of a New England salt marsh: Ecologi- cal Monographs, v. 42, p. 201-237. Roman, C.T., Niering, W.A., and Warren, R.S., 1984, Salt marsh vegeta- tion change in response to tidal restriction: Environmental Manage- ment, v. 8, p. 141-150. Rozsa, Ronald, 1988, An overview of wetland restoration projects in Con- necticut, in Lefor, M.W., and Kennard, W.C., eds., Proceedings of the 4th Wetlands Conference, November 15,1986: University of Connecti- cut Institute of Water Resources Report 34, p. 1-11. Schafer, J.P., and Hartshorn, J.H., 1965, The Quaternary of New England, in Wright, H.E., Jr., and Frey, D.G., eds., The Quaternary of the United States: Princeton, N.J., Princeton University Press, p. 113-128. Thorson, R.M., 1990, Development of small upland wetlands A strati- graphic study in northeastern Connecticut: Storrs, University of Con- necticut School of Engineering, Final Report JHR 90-191, 285 p. 146 National Water Summary Wetland Resources: STATE SUMMARIES ____1992, Remaking the wetlands in Lebanon, Connecticut Cultural and natural changes in the postglacial epoch: Storrs, University of Con- necticut School of Engineering, Final Report JHR 92-215, 157 p. Thorson, R.M., and Harris, S.L., 1991, How "natural" are inland wet- lands? An example from the Trail Wood Audubon Sanctuary in Connecticut, USA: Environmental Management, v. 15, p. 675-687. Welsh, B.L., Herring, J.P., Bessette, Diane, and Read, Luana, 1976, The importance of an holistic approach to ecosystem management and planning, in Lefor, M.W., Kennard, W.C., and Helfgott, T.B., eds., Proceedings of the 3rd Wetlands Conference, June 14, 1975: Univer- sity of Connecticut Institute of Water Resources Report 2_6, p. 16-33. Winter, T.C., 1988, A conceptual framework for assessing cumulative im- pacts on the hydrology of nontidal wetlands: Environmental Manage- ment, v. 12, p. 605-620. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Survey, Ribicoff Federal Building, 450 Main Street, Room 525, Hartford, CT 06103; Regional Wetlands Coordinator, U.S. Fish and Wildlife Service, 300 Westgate Center Drive, Hadley, MA 01035 Prepared by Sandra L. Harris, U.S. Geological Survey National Water Summary Wetland Resources 147 Delaware Wetland Resources We'etlands cover about 17 percent of Delaware (Tiner and Finn, 1986). These wetlands support rich biotic communities in freshwa- ter, brackish-water, and saltwater settings across the State. Some of the most familiar wetlands in Delaware are the tidal marshes along Delaware Bay (fig. I). Wetlands have many chemical, physical, and biological func- tions. In Delaware, wetlands trap waterborne sediments, nutrients, and toxic chemicals by filtering inflowing water and storing or trans- forming the filtrate. Coastal-zone and flood-plain wetlands mitigate the effects of flooding caused by runoff and tides by reducing flow velocity, storing water temporarily, and releasing it gradually. Veg- etation in riparian wetlands maintains stream channels by stabiliz- ing the land surface, and tidal wetlands act as buffers against storm tides and waves, thus impeding erosion. One of the most important functions of wetlands is habitat for waterfowl, terrestrial and aquatic animals, and a wide variety of plant life. Wetlands provide food, shelter, resting and feeding places on migration routes, breeding areas, and nurseries for many animals including species of particu- lar economic interest in Delaware such as muskrat, fish, ducks, and geese. Many rare and endangered plant species are adapted to hy- drologic conditions present only in wetlands, especially freshwater wetlands. Delaware's wetlands have considerable recreational and eco- nomic value. They provide outdoor educational and recreational opportunities, including activities such as bird watching, hiking, and canoeing. In addition, wetlands in Delaware support the hunting, fur trapping, commercial and sport fishing, lumbering, and tourist industries. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deep- water habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and oth- ers, 1979). The distribution of wetlands and deepwater habitats in Delaware is shown in figure 2/4; only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are Figure 1. Estuarine wetlands on Cedar Creek at Slaughter Beach, Delaware. These are tidal wetlands typical of those found along Delaware Bay. (Photograph by Evelyn M. Maur- meyer, Coastal and Estuarine Research, Inc.) grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Delaware are described below. System Palustrine, Lacustrine Riverine Estuarine. Marine.. Wetland description Nontidal and tidal-freshwater wetlands in which vegetation is predominantly trees {forested wet- lands); shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted herba- ceous plants (persistent- and nonpersistent- emergent wetlands); or submersed and (or) floating plants (aquatic beds). Also, intermit- tently to permanently flooded open-water bod- ies of less than 20 acres in which water is less than 6.6 feet deep. Nontidal and tidal-freshwater wetlands within an intermittently to permanently flooded lake or reservoir larger than 20 acres and (or) deeper than 6.6 feet. Vegetation, when present, is pre- dominantly nonpersistent emergent plants (non- persistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds), or both. Nontidal and tidal-freshwater wetlands within a channel. Vegetation, when present, is same as in the Lacustrine System. Tidal wetlands in low-wave-energy environments where the salinity of the water is greater than 0.5 part per thousand (ppt) and is variable owing to evaporation and the mixing of seawater and freshwater. Tidal wetlands that are exposed to waves and cur- rents of the open ocean and to water having a salinity greater than 30 ppt. Palustrine wetlands are the most abundant wetlands in Dela- ware, comprising 132,000 acres in 1983, or about 59 percent of the wetland area in the State (Tiner, 1985). Palustrine wetlands are dis- tributed throughout the State in topographic depressions and in ri- parian zones along rivers and streams. In 1983, estuarine wetlands covered 89,800 acres in Delaware, or about 40 percent of the wet- land area in the State. Estuarine wetlands occur along the shores of Delaware Bay and the Delaware River and behind the barrier beaches of the Atlantic Coast. Other types of wetland comprise less than 1 percent of Delaware's wetland area. In 1983, the State had about 650 acres of riverine wetland, 140 acres of lacustrine wet- land, and 540 acres of marine wetland (mostly beaches and sand- bars along the Atlantic Coast). Delaware is a small State, but it contains many different types of wetlands. The plant composition of vegetated wetlands is deter- mined by factors such as climate, soil type, ground-water and sur- face-water chemistry, salinity, and the extent and duration of flood- ing. The predominant vegetation or specific location of a Delaware wetland frequently determines its common name. For example, in- land bays are natural coastal features that contain both palustrine and estuarine emergent wetlands, and such wetlands occur in Rehoboth, Indian River, and Little Assawoman Bays. Palustrine and estuarine emergent wetlands can be found in impoundments modi- fied by constructed levees and managed by water-control structures. Salt and brackish marshes are predominantly estuarine emergent wetlands characterized by vegetation tolerant of brackish to salty 148 National Water Summary Wetland Resources: STATE SUMMARIES water; small scrub-shrub wetlands commonly are associated with the landward margins of salt marshes. Interdunal swales (dune slacks) are topographic depressions among sand dunes on the At- lantic Coast that contain palustrine emergent or scrub-shrub wet- lands. Palustrine forested wetlands in Delaware include Atlantic white cedar swamps, cypress swamps, and flood-plain forests, both tidal and nontidal. Delmarva bays (small, closed topographic depres- sions) commonly contain seasonally flooded palustrine emergent, scrub-shrub, or forested wetlands. Delmarva bays and associated wetlands also are known as whale wallows; loblollies; flatwoods depressions; and intermittent, temporary, vernal, woodland, or coastal-plain ponds. The Delaware Department of Natural Resources and Environ- mental Control has established five wetland categories for the State based on relative functions and values of the State's wetlands. Cat- egory I wetlands provide exceptional value or unique biotic assem- blages and include Delmarva bays, dune slacks, Atlantic white cedar swamps, and cypress swamps. Category II wetlands are those gen- erally considered permanently to seasonally wet or those that pro- vide significant habitat or biotic values. Category III wetlands in- clude temporarily flooded wetlands and all wetlands not included in another category. Category IV wetlands consist of farmed wetlands. Category V wetlands are all wetlands created from nonwetland areas for purposes other than mitigation and include drainage ditches, farm ponds, storm water-retention basins, and borrow pits. PHYSIOGRAPHIC DIVISIONS COASTAL PLAIN HYDROCEOMORPHIC REGIONS CD Poorly Drained Upland CD Well-Drained Upland HE] Surficial Confined CD Inner Coastal Plain Coastal Wetland and Beach Region CD Piedmont Province WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown ^^^1 Predominantly wetland Predominantly deepwater habitat 78 « 30' 10 15 MILES 10 15 KILOMETERS Figure 2. Wetland distribution in Delaware and physical features that control wetland distribution in the State. A, Distribution of wetlands and deepwater habitats. B, Physiography. C, Hydrogeomorphic regions in the Coastal Plain of Delaware. (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 1991. B, Landforms data from EROS Data Center; divisions from Spoljarik and Jordan, 1966. C, Shedlock and others, 1993.) National Water Summary Wetland Resources: DELAWARE 149 HYDROLOGIC SETTING In Delaware, water in small, nontidal wetlands is supplied by direct precipitation, surface runoff from precipitation, and localized, shallow ground-water-flow systems recharged by precipitation. Larger wetlands (tidal and nontidal) also can interact with regional ground-water-flow systems. The primary source of water in tidal wetlands is tidal inundation, although runoff and ground-water dis- charge can be important secondary sources. Water from surface runoff can collect in topographic lows, where ground water com- monly discharges after periods of greater-than-normal precipitation. These hydrologic conditions are conducive to the formation and maintenance of wetlands. Abundant precipitation (an annual average of 43 inches) (Simmons, 1986) and extensive tidal zones in Delaware Bay and the Atlantic Ocean provide ample water for wetlands in Delaware. Fluc- tuations in local precipitation and evapotranspiration rates combine with local differences in geology, topography, soil characteristics, and tides to create transient or seasonal changes in the local inter- actions of ground water and surface water in wetlands (Winter, 1992; Phillips and Shedlock, 1993). In general, mid-October to early April (nongrowing season) is a period of ground-water recharge, with high rates of precipitation and low rates of evapotranspiration. Mid-April to mid-October (growing season) is characterized by high rates of evapotranspiration and declining water levels (Johnston, 1973). Delaware is in two physiographic provinces: the Coastal Plain and the Piedmont Province (fig. IE ). Geology, topography, and soils in the two provinces differ considerably; the types and distribution of wetlands in each province reflect this difference. Figure 3A-3C is a generalization of wetland hydrology in Delaware. Coastal Plain. Ninety-three percent of Delaware, including more than 94 percent of its wetland area, is in the Coastal Plain. All of the estuarine wetlands in the State are in this relatively flat province (Tiner, 1987), which rises from below sea level only to about 100 feet above sea level. The Coastal Plain is underlain by an extensive and locally complex surficial aquifer that has a wide range of depth, porosity, and permeability (Andres, 1987; Talley, 1987). Wetlands in the Coastal Plain generally intersect the surficial aqui- fer. Coastal Plain wetlands are supported by precipitation, surface runoff, flooding from streams, and ground-water discharge. Re- charge of the ground-water system in the Coastal Plain is mainly by infiltration of precipitation in interstream areas (Heath, 1984), and discharge results from evapotranspiration and by seepage to streams, estuaries, wells, ditches, and the ocean. Both local and regional ground-water flow may help sustain wetlands, especially in low-lying areas near the coast, which contain extensive, mainly emergent wetlands. Forested wetlands occur primarily in bottom lands along stream channels, especially in headwater areas. The width of these forested wetlands in streamside and upland areas commonly has been reduced by ditching and the conversion of land to agricultural use. Regional differences in the configuration and geohydrologic properties of sedimentary deposits in the Coastal Plain are reflected by differences in topography, soils, degree of stream incision, the configuration of the water table, and the paths of ground-water flow. These characteristics, which affect the distribution of wetlands in the landscape, have been used to divide the Coastal Plain on the Delmarva Peninsula into hydrogeomorphic regions (Shedlock and others, 1993). In Delaware, there are five hydrogeomorphic regions (fig. 2C): the Poorly Drained Upland, the Well-Drained Upland, the Surficial Confined, the Inner Coastal Plain, and the Coastal Wet- land and Beach. Each of these regions contains wetlands. The Poorly Drained Upland lies along the drainage divide sepa- rating the Chesapeake Bay drainage basin to the west from the drain- age basins of Delaware Bay and the Atlantic Ocean. This region is hummocky, has low relief, and has many seasonally flooded forested wetlands and small, sluggish streams in poorly defined, low-gradi- ent, shallowly incised valleys (fig. 3A) (Shedlock and others, 1993). About 43 percent of the region is forested, including the topographic depressions, which have poorly drained soils and typically contain wetlands. Forests are interspersed with agricultural fields that are in areas of higher elevation than the forests. The water table in this region is shallow and has a relatively large seasonal fluctuation. Local ground-water-flow patterns are directly affected by the depth of the water table and can differ with seasonal precipitation, even to the extent of changing direction, so that wetlands where ground water is discharged in wet periods can become areas of ground-water recharge during dry periods (Phillips and Shedlock, 1993). Typical wetlands in this region are seasonally saturated, forested wetlands. Examples include the wetlands in Redden State Forest, which have poorly defined topographic boundaries (typical of the southern part of this region), and the small wetlands in Blackbird State Forest, which are contained within Delmarva bays (typical of the northern part of this region). The Well-Drained Upland occurs in a north-south trending band in eastern Delaware and in an area in the southern part of the State around the headwaters of the Nanticoke River. This region is flat to gently rolling and has higher relief than the Poorly Drained Upland (fig. 3A). Streams are deeply incised, particularly tidal streams and their tributaries. About 28 percent of the Well-Drained Upland is forested, primarily in riparian (streamside) zones, which include most of the wetlands in the region. The rest of the region is covered by agricultural fields. Typical wetlands in the region include the palustrine forested wetlands along the Nanticoke River. The Coastal Wetland and Beach region extends southward along the coast of Delaware from the Delaware River to the Dela- ware-Maryland border. This region is very flat and has dunes along the Atlantic Coast (fig. 3A ). The surficial aquifer is composed of a variety of sediments that were deposited in several coastal settings, including beach, dune, and tidal marsh. The water table is gener- ally within a few feet of the land surface because of geohydrologic conditions and because the land-surface altitude is near sea level. Wetlands in this region have complex hydrology because of the geologic setting and because of the interactions between tides and ground-water discharge. Extensive wetlands in low-lying areas form as shallow embayments, salt marshes, and tidal and nontidal fresh- water marshes and swamps. Examples of wetlands in the Coastal Wetland and Beach region include the large marshes in Indian River Bay, the Great Marsh (an extensive tidal marsh along Delaware Bay), and the freshwater and brackish tidal marshes along Blackbird Creek. The Surficial Confined region occupies two small areas of southern Delaware. The landscape is flat, except for a number of low, sandy ridges (relict dunes) that rise above their surroundings (fig. 3fi). This region is physiographically similar to the Poorly Drained Upland. Geohydrologic conditions in the upper sand unit of the aquifer are the cause of the poor drainage conditions and widespread presence of wetlands in the Surficial Confined region (Shedlock and others, 1993). Extensively ditched agricultural lands have been converted from former wetland. About 55 percent of the area in this region is still in large tracts of woodlands that occur in uplands between streams and in wetlands in riparian zones. Ex- amples of wetlands in the Surficial Confined region include the remnant of a large cypress swamp located east of Gumboro and the forested wetlands along the Pocomoke River. The Inner Coastal Plain is in northern Delaware. There is con- siderable topographic relief in this region, and streams are well in- cised in their lower reaches (fig. 3C). Land use in this region is heterogeneous. There has been considerable development of the northeastern section, which is mostly urban. The northwestern sec- tion of the region is forested, and the southern section has mixed 150 National Water Summary Wetland Resources: STATE SUMMARIES agricultural and residential usage. Wetlands in the Inner Coastal Plain occur in riparian zones, especially in the tidal reaches of the Christina River, in forested areas, and in small, discontinuous ar- eas. Examples of wetlands in the region include Churchman's Marsh, a tidal emergent wetland; Nonesuch Creek Marsh, an emergent wetland whose tidal flow is restricted by tide gates; and the small, nontidal, palustrine wetlands around Noxontown Pond. Piedmont Province. The Piedmont Province occupies the northern 6 percent of the State and contains only 2 percent of Delaware's total wetland area (Tiner and Finn, 1986). The gently rolling hills of this province range in altitude from near sea level to about 450 feet. The Piedmont Province is underlain by folded and faulted igneous and metamorphic bedrock overlain by a regolith of variable thickness. Regolith, which underlies the land surface nearly everywhere in this province, is a layer of unconsolidated, mostly fine-grained material composed of fragmental, weathered bedrock and alluvium overlying unweathered bedrock. Wetlands in the Pied- mont Province occur along riparian valleys and other low areas of the ground surface, which commonly occur over fracture zones in the bedrock. Water is more likely to collect and be discharged in these depressions than in other areas because fracture zones are major pathways of ground-water movement (Heath, 1984). A. Poorly Drained Upland, Well-Drained Upland, and Coastal Wetland and Beach POORLY DRAINED UPLAND PALUSTRINE WETLAND PALUSTRINE WETLANDS WELL DRAINED UPLAND RIVERINE WETLANDS COASTAL WETLAND AND BEACH ESTUARINE WETLAND ESTUARINE WETLAND Confining unit Saltwater Estuarine deposits EXPLANATION ^- Generalized direction of ground-water flow Average water table Water table in Poorly Drained Upland in wet season Water table in Poorly Drained Upland in dry season i=- Direction of ground-water flow in Poorly Drained Upland in wet season t V Scrub-shrub vegetation Forest vegetation Emergent vegetation Farmed crops Submersed aquatic vegetation j Channel-fill sediments Direction of ground-water ___ flow in Poorly Drained |___l Regolith Upland in dry season ----- Contact between fresh- water and saltwater Note: Vertical scale greatly exaggerated C Piedmont Province and Inner Coastal Plain RIVERINEJWETLAND HEDMONT pROV|NCE PALUSTRINE WETLANDS PALUSTRINE WETLANDS ESTUARINE WETLAND "O c J5 INNER COASTAL PLAIN RIVERINE WETLANDS Figure 3. Geohydrologic setting of wetlands in Delaware. A, Poorly Drained Upland, Well-Drained Upland, and Coastal Wetland and Beach. B, Surficial Confined region. C, Piedmont Province and Inner Coastal Plain. National Water Summary Wetland Resources: DELAWARE 151 Recharge of the ground-water system in the Piedmont Prov- ince is by infiltration of precipitation, mostly in the uplands (Heath, 1984); however, most precipitation in this province is transported to surface depressions and streams by overland runoff. In forested areas, water seeps into the soil layer and moves through it laterally to discharge into streams and, by evapotranspiration, into the atmo- sphere. Some water moves below the soil zone to the water table in the regolith. The water seeps from the regolith into the underlying bedrock or discharges to surface-water bodies (fig. 3C). Much of the ground water available to wetlands in this region is stored in the regolith (Metzgar, 1973). Types of wetlands in the Piedmont Province include flood-plain emergent marshes, seeps, and excavated farm ponds. Notable among wetlands in this province are the forested wetlands along Brandy- wine Creek. TRENDS In the 1780's, about 480,000 acres (36 percent) of Delaware was wetland (Dahl, 1990). By the mid-1980's, 223,000 wetland acres remained a loss of about 54 percent since the 1780's. The esti- mated annual loss of all types of wetland between 1955 and 1981 was 1,600 acres (Tiner, 1987). Both human activities that adversely affect water quality and natural phenomena have contributed to widespread wetland loss and degradation. Major causes of vegetated nontidal wetland loss have been channelization and ditching (about 55 percent), direct conversion to agriculture (28 percent), urbanization (12 percent), and pond creation (5 percent) (Tiner, 1987). Major causes of vegetated tidal wetland loss have been urbanization (63 percent), inundation by submersion, dredging, or impoundment (24 percent), and pond cre- ation (6 percent). Small areas of wetland have been formed in re- cent times, especially by inadvertent flooding during road construc- tion, by pond construction and, most recently, by the establishment of compensatory wetland-mitigation sites. Properly managed shal- low ponds and impoundments do not usually result in wetland losses but rather in conversions from drier to wetter types of wetlands; they can even yield net increases in wetland value with the change in function. New wetlands also have formed on washover fans and flood tidal deltas along coastal areas as well as on former upland areas inundated by rising sea levels. Implementation of the 1973 State Wetlands Act and the 1972 Federal Clean Water Act markedly reduced the rate of human-caused tidal wetland loss. The estimated annual tidal wetland loss between 1954 and 1973 was 444 acres (Lesser, 1971); between 1973 and 1979 the estimated annual rate of tidal-wetland loss was 20 acres (Hardisky and Klemas, 1983). Recent rates of nontidal-wetland loss have not been accurately quantified. CONSERVATION Many government agencies and private organizations partici- pate in wetland conservation in Delaware. The most active agencies and organizations and some of their activities are listed in table 1. Federal wetland activities. Development activities in Dela- ware wetlands are regulated by several Federal statutory prohibi- tions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Harbors Act; the 1972 Clean Water Act and amendments; the 1985 Food Security Act; the 1990 Food, Agriculture, Conservation, and Trade Act; the 1986 Emergency Wetlands Resources Act; and the 1972 Coastal Zone Management Act. Section 10 of the Rivers and Harbors Act gives the U.S. Army Corps of Engineers (Corps) authority to regulate certain activities in navigable waters. Regulated activities include diking, deepening, filling, excavating, and placing of structures. The related section 404 of the Clean Water Act is the most often-used Federal legislation protecting wetlands. Under section 404 provisions, the Corps issues permits regulating the discharge of dredged or fill material into wetlands. Permits are subject to review and possible veto by the U.S. Environmental Protection Agency, and the FWS has review and ad- visory roles. Section 401 of the Clean Water Act grants to States and eligible Indian Tribes the authority to approve, apply conditions to, or deny section 404 permit applications on the basis of a pro- posed activity's probable effects on the water quality of a wetland. Most farming, ranching, and silviculture activities are not sub- ject to section 404 regulation. However, the "Swampbuster" provi- sion of the 1985 Food Security Act and amendments in the 1990 Food, Agriculture, Conservation, and Trade Act discourage (through financial disincentives) the draining, filling, or other alteration of wetlands for agricultural use. The law allows exemptions from pen- alties in some cases, especially if the farmer agrees to restore the altered wetland or other wetlands that have been converted to agri- cultural use. The Wetlands Reserve Program of the 1990 Food, Agriculture, Conservation, and Trade Act authorizes the Federal Government to purchase conservation easements from landowners who agree to protect or restore wetlands. The Consolidated Farm Service Agency (formerly the Agricultural Stabilization and Con- servation Service) administers the Swampbuster provisions and Wet- lands Reserve Program. The Natural Resources Conservation Ser- vice (formerly the Soil Conservation Service) determines compli- ance with Swampbuster provisions and assists farmers in the iden- tification of wetlands and in the development of wetland protection, restoration, or creation plans. The 1986 Emergency Wetlands Resources Act and the 1972 Coastal Zone Management Act and amendments encourage wetland Table 1 . Selected wetland-related activities of government agencies and private organizations in Delaware, 1993 [Source: Classification of activities is generalized from information provided by agencies and organizations. , agency or organization participates in wetland-related activity;..., agency or organization does not participate in wetland-related activity. MAN, management; REG, regulation; R&C, resto- ration and creation; LAN, land acquisition; R&D, research and data collec- tion; D&l, delineation and inventory] Agency or organization FEDERAL Department of Agriculture Consolidated Farm Service Agency.............. Natural Resources Conservation Service ... Department of Commerce National Oceanic and Atmospheric Administration ........................... Department of Defense Army Corps of Engineers ................................. Department of the Interior Fish and Wildlife Service ................................. Geological Survey............................................. National Biological Service ............................ National Park Service ...................................... Environmental Protection Agency...................... STATE Delaware Geological Survey.............................. Department of Natural Resources and Environmental Control ........................................... State Highway Administration ............................ University of Delaware College of Marine Studies ............................... SOME COUNTY AND LOCAL GOVERNMENTS PRIVATE ORGANIZATIONS The Nature Conservancy..................................... Delaware Wild Lands, Inc. .................................. Delaware Nature Society..................................... Ducks Unlimited...................................................... 152 National Water Summary Wetland Resources: STATE SUMMARIES protection through funding incentives. The Emergency Wetland Resources Act requires States to address wetland protection in their Statewide Comprehensive Outdoor Recreation Plans to qualify for Federal funding for State recreational land; the National Park Ser- vice provides guidance to States in developing the wetland compo- nent of their plans. Coastal States that adopt coastal-zone manage- ment programs and plans approved by the National Oceanic and Atmospheric Administration are eligible for Federal funding and technical assistance through the Coastal Zone Management Act. State wetland activities. Delaware's State Wetlands Act, en- acted in 1973, protects coastal tidal wetlands, including some fresh- water wetlands along tidal rivers, and requires a permit from the Department of Natural Resources and Environmental Control for many activities in these wetlands. A proposed freshwater (nontidal) wetlands statute would establish a State-run nontidal-wetlands regu- latory program based on five categories of wetlands. This would be part of a comprehensive statewide management program and is in- tended to result in the assumption of authority for the Federal sec- tion 404 program by the State. The Department of Natural Resources and Environmental Control also administers section 401 of the Federal Clean Water Act, providing regulatory control in wetland areas in terms of effects on surface-water-quality standards. The coastal-zone management program in Delaware bars the develop- ment of heavy manufacturing industry within 2 miles of the State's coastline where wetlands are abundant, while allowing the devel- opment of light industry and the expansion of preexisting industry under a permit system. Permits are also required for substantial changes to the character of beach or open-water areas. The Sub- aqueous Lands Act and the Beach Preservation Act regulate activi- ties in tidal and nontidal subaqueous navigable waters and within the coastal dune systems along the Atlantic Ocean and Delaware Bay. Private wetland activities. Private organizations with inter- ests in wetlands in Delaware are active in the development of regu- lations, policy planning, advocacy, land acquisition and manage- ment, environmental education, and research. A few of the many such organizations in the State are The Nature Conservancy, the Delaware Nature Society, Delaware Wild Lands, Inc., the Sierra Club, Ducks Unlimited, and the Brandy wine Conservancy. References Cited Andres, A.S., 1987, Geohydrology of the northern coastal area, Delaware: Delaware Geological Survey Hydrologic Map Series no. 5, scale 1:24,000. Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Dahl, I.E., 1990, Wetlands Losses in the United States, 1780's to 1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 13 p. Hardisky, M.A., and Klemas, Vytautas, 1983, Tidal wetlands natural and human-made changes from 1973 to 1979 in Delaware Mapping tech- niques and results: Environmental Management, v. 7, no. 4, p. 339- 344. Heath, R.C., 1984, Ground-water regions of the United States: U.S. Geo- logical Survey Water-Supply Paper 2242, 78 p. Johnston, R.H., 1973, Hydrology of the Columbia (Pleistocene) deposits of Delaware: Delaware Geological Survey Bulletin 14, 78 p. Lesser, C.A., 1971, Memorandum to Secretary Austin N. Heller from Charles Lesser RE 1971 wetland inventory (corrected): Dover, Del., Department of Natural Resources and Environmental Control, 3 p. Metzgar, R.G., 1973, Wetlands in Maryland: Maryland Department of State Planning Publication 157, 80 p. Phillips, P.J., and Shedlock, R.J., 1993, Hydrology and chemistry of ground- water and seasonal ponds in the Atlantic Coastal Plain in Delaware, U.S.A.: Journal of Hydrology, v. 141, p. 157-178. Shedlock, R.J., Hamilton, P.A., Denver, J.M., and Phillips, P.J., 1993, Multiscale approach to regional ground-water quality assessment of the Delmarva Peninsula, in Alley, W.M., ed., Multiscale approach to regional ground-water quality assessment: New \brk, Van Nostrand Reinhold & Co., p. 563-587. Simmons, R.H., 1986, Delaware surface-water resources, in U.S. Geologi- cal Survey, National water summary 1985 Hydrologic events and surface-water resources: U.S. Geological Survey Water-Supply Paper 2300, p. 181-186. Spoljaric, Nenad, and Jordan. R.R., 1966, Generalized geologic map of Delaware: Newark, Del., Delaware Geological Survey map, scale 1:296,075. Talley, J.H., 1987, Geohydrology of the southern coastal area: Delaware Geological Survey Hydrologic Map Series no. 7, scale 1:24,000. Tiner, R.W., 1985, Wetlands of Delaware: Newton Corner, Mass., U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control cooperative publication, 77 p. ____1987, Mid-Atlantic wetlands A disappearing natural treasure: Newton Corner, Mass., U.S. Fish and Wildlife Service and U.S. En- vironmental Protection Agency cooperative publication, 28 p. Tiner, R.W., and Finn, J.T., 1986, Status and recent trends of wetlands in five mid-Atlantic states Delaware, Maryland, Pennsylvania, Vir- ginia, and West Virginia: Newton Corner, Mass., U.S. Fish and Wild- life Service, National Wetlands Inventory Project technical report, 40 p. Winter, T.C., 1992, A physiographic and climatic framework for hydrologic studies of wetlands, in Robarts, R.D., and Bothwell, M.L., eds., Pro- ceedings of the Symposium on Aquatic Ecosystems in Semi-Arid Regions, 1990: Saskatoon, Saskatchewan, Environment Canada, The National Hydrology Research Institute Symposium Series no. 7, p. 127-147. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Survey, 208 Carroll Building, 8600 LaSalle Road, Towson, MD 21286; Regional Wetland Coordinator, U.S. Fish and Wildlife Service, 300 Westgate Center Drive, Hadley, MA 01035 Prepared by Martha A. Hayes, U.S. Geological Survey U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources 153 Florida Wetland Resources retlands covered more than one-half of Florida, approximately 20.3 million acres, in predevelopment times. Although only about one-half of the original wetlands remain, Florida still has more wetlands than any of the other 47 conterminous States (Dahl, 1990). Wetlands in Florida are diverse and include types that are rare in other States, such as mangrove swamps and hydric hammocks. As- sociations of warm-temperate and subtropical wetlands not found elsewhere are common in Florida, a prime example being the unique complex of extensive sawgrass marshes and other wetlands known as The Everglades (fig. 1). Florida's wetlands have considerable economic and environ- mental value. In river basins, flood-plain wetlands reduce down- stream flood damages by retaining overflows in backwater ponds and depressions. Organic soils in many wetlands can store large quantities of water and release it slowly to plants during drought. Wetlands can filter out and accumulate pollutants from surface water some cypress depressions in Florida have been used spe- cifically for wastewater treatment (Dierberg and Brezonik, 1984). Many rare or endangered plant and animal species, such as the in- sectivorous white-top pitcherplant and the snail kite, live in Florida wetlands. Wetlands provide breeding and feeding grounds for resi- dent and migratory birds. Coastal wetlands such as salt marshes, mangrove swamps, and seagrass beds are nursery areas for sea tur- tles and economically important species such as shrimp, blue crab, oyster, mullet, spotted seatrout, and red drum (Tiner, 1984; Palik andKunneke, 1984). In the past, wetlands were considered obstacles to the devel- opment of the State. Widespread destruction and degradation of wetlands, however, resulted in drastic losses of wildlife, water short- ages, and water-quality problems (Prayer and Hefner, 1991). Today, Florida's wetlands are considered important resources and are pro- tected by laws that preserve their esthetic and ecological value. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deep- water habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and oth- ers, 1979). The distribution of wetlands and deepwater habitats in Florida is shown in figure 2A\ only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Florida are described below. System Palustrine. Lacustrine . Figure 1. Sawgrass marsh and tree islands in the Everglades-Big Cypress region of southern Florida. (Photograph courtesy of Florida State Archives.) Wetland description . Nontidal and tidal-freshwater wetlands in which vegetation is predominantly trees (forested wet- lands); shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted herba- ceous plants (persistent- and nonpersistent- emergent wetlands); or submersed and (or) floating plants (aquatic beds). Also, intermit- tently to permanently flooded open-water bod- ies of less than 20 acres in which water is less than 6.6 feet deep. .. Nontidal and tidal-freshwater wetlands within an intermittently to permanently flooded lake or reservoir larger than 20 acres and (or) deeper than 6.6 feet. Vegetation, when present, is pre- dominantly nonpersistent emergent plants (non- persistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds), or both. .. Nontidal and tidal-freshwater wetlands within a channel. Vegetation, when present, is same as in the Lacustrine System. .. Tidal wetlands in low-wave-energy environments where the salinity of the water is greater than 0.5 part per thousand (ppt) and is variable owing to evaporation and the mixing of seawater and freshwater. .. Tidal wetlands that are exposed to waves and cur- rents of the open ocean and to water having a salinity greater than 30 ppt. Lacustrine and riverine wetlands are not addressed in this re- port. They constitute a relatively small part of Florida's wetlands and were not distinguished from deepwater habitats by the FWS National Wetlands Inventory (Prayer and Hefner, 1991). Palustrine System. Eighty-seven percent of Florida's wetlands are in the Palustrine System. Palustrine forested wetlands cover 5.5 Riverine. Estuarine. Marine. 154 National Water Summary Wetland Resources: STATE SUMMARIES million acres, nearly one-half the acreage of all Florida wetlands (Prayer and Hefner, 1991). These wetlands, which are widely dis- tributed throughout the State, fringe rivers and lakes, line small drainages and sloughs, form in small depressions and ponds, and cover wet flatwoods. The predominant trees can be pines, hard- woods, or cypress. Pine flatwoods, the most common ecological community in Florida, are distributed statewide. These communities are on flat land and have poorly drained, acidic, sandy soils that commonly are underlain by a clay or organic hardpan. Pine flatwoods can be a mixture of both wetland and upland communities that are difficult to delineate. Discrepancies between present-day estimates of 8.2 and 11.0 million acres of remaining wetlands in Florida (Prayer and Hefner, 1991; Kautz, 1991) might be due primarily to difficulties inherent in distinguishing wet from dry flatwoods. Wet flatwoods can grade into dry flatwoods with imperceptible changes in eleva- tion. In many areas, numerous seasonal ponds, small streams, and other wetlands are embedded within the larger pine-flatwoods matrix. In wet flatwoods, soils can remain saturated through much of the rainy season, and there can be standing water for 1 to2months every year. During the dry season, however, high evapotranspira- tion from sandy soils and an impermeable hardpan preventing up- ward movement of ground water result in dry conditions that can persist for months (Abrahamson and Hartnett, 1990). Palustrine forested wetlands in which mixed hardwoods pre- dominate cover about 2 million acres of Florida (Kautz, 1991) and comprise many wetland types. Bottom-land hardwood forests on river flood plains are most common in the northern part of the State, reaching their greatest extent in the alluvial flood plains of the pan- handle (Wharton and others, 1977). Tree diversity can be high in alluvial flood plains: a study of the flood-plain forest bordering the Apalachicola River (Leitman and others, 1984) recorded 47 tree WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown Predominantly wetland Predominantly deepwater habitat WAVE ENERGY Average breaker height In centimeters Low Moderate High 0-10 10-50 Above 50 Figure 2. Distribution of wetlands and deepwater habitats in Florida and physical and climatological features that control wetland distribu- tion in the State. A, Distribution of wetlands and deepwater habitats. B, Wave height along the Florida coast. (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 1991. B, Car/ton, 1977.) National Water Summary Wetland Resources: FLORIDA 155 species and 5 major tree communities. Blackwater streams, which are common in Florida, are dark colored owing to the presence of organic acids from decaying vegetation. The Suwannee River, which has characteristics of both blackwater and spring-fed streams, has an extensive flood-plain forest in its lower reaches. Bay swamps, black gum swamps, and other mixed-hardwood wetlands that form in depressions are common throughout Florida. These forested wetlands often are mixed with shrub bogs (scrub-shrub wetlands) as in the Apalachicola National Forest and in Pinhook Swamp, the southern extension of the Okefenokee Swamp in Florida (Wharton and others, 1977). Shrub bogs are depressional wetlands that have acidic, organic soils and that typically are dominated by titi, gallberry, fetterbush, and other evergreen shrubs (U.S. Soil Con- servation Service, 1989). Hydric hammocks, which form on poorly drained soils or soils saturated by near-surface water tables and in which evergreen oaks such as live oak and swamp laurel oak pre- dominate, are rare outside Florida (Vince and others, 1989). Ex- otic tree species such as melaleuca have invaded wetlands in south- ern Florida to such an extent that some authors consider wetlands in which they are the predominant vegetation to belong to a distinct forested-wetland type (Wharton and others, 1977; Ewel, 1990). Palustrine forested wetlands in which cypress predominates cover about 1.6 million acres in Florida (Kautz, 1991). Cypress domes are small, isolated, depressional wetlands that have convex silhouettes when viewed from a distance. They are acidic, stillwater swamps thai have standing water at least part of the year, and many have a permanent central pond. The Green Swamp in west-central Florida has a high density of cypress domes in a pine-flatwoods matrix (McPherson, 1979). Large swamps in which cypress pre- dominates commonly ring lakes or line watercourses. Cypress strands are linear cypress swamps along watercourses. Fakahatchee Strand State Preserve in southwestern Florida contains an outstand- ing example of a cypress strand; the wetland harbors rare orchids. palms, and the endangered Florida panther (Grow, 1989). Cypress scrub is a drier community of stunted cypress found primarily in southern Florida on nutrient-poor, calcium-carbonate-rich soils or shallow sand over limestone. Big Cypress National Preserve has large areas of cypress scrub in which mature cypress trees usually are less than 20 feet tall. Palustrine emergent wetlands such as freshwater marshes and wet prairies cover 2.9 million acres of Florida (Prayer and Hefner, 1991). Freshwater marshes are concentrated in southern Florida, where about 1.6 million acres remained in 1973, including 624,000 acres of sawgrass marshes (Odum and Brown, 1977). Other major marsh systems include those in the Kissimmee and St. Johns River flood plains (Kushlan, 1990). Freshwater marshes are inundated most of the year, have thick accumulations of organic materials, and burn infrequently. Wet prairies usually are inundated for less than one-half of the year, have less organic accumulation, and burn more frequently every 1-3 years if fuel is sufficient. Fires maintain both wetland types by limiting the invasion of woody vegetation and retarding the accumulation of organic matter (Kushlan, 1990). Estuarine and Marine Systems. Florida has about 1.4 mil- lion acres of estuarine and marine intertidal wetlands along 1,200 miles of coastline. About 12 percent of Florida's wetlands are es- tuarine, and less than 1 percent are marine. Tides cycle terrestrial sediments, nutrients, and detritus through coastal wetlands, mak- ing them highly productive ecological communities (Florida Natu- ral Areas Inventory and Division of State Lands, 1990). The most common coastal wetlands are salt marshes, mangrove swamps, and seagrass beds. Salt marshes are emergent wetlands that develop along low- wave-energy coastlines and in estuaries. Wave energy (fig. 2B), salinity, frequency of inundation, and tidal range vary along the coasts, resulting in substantial differences in the areal extent and plant-species composition of these marshes. The most extensive D DAYS BELOW FREEZING Line of equal annual number of days in which temperature is 32 F or lower Dashed where approximately located. Interval is variable TOPOGRAPHY AND BATHYMETRY Interval is in feet i 250 200 150 100 50 -- Sea level B Figure 2. Continued. Distribution of wetlands and deepwater habitats in Florida and physical and climatological features that control wetland distribution in the State. C, Topography of Florida and bathymetry of adjacent offshore waters. D, Average annual number of days in which temperature is 32°F or lower. (Sources: C, Fernald, 1981. D, Conway and Listen, 1990.) 156 National Water Summary Wetland Resources: STATE SUMMARIES development of salt marshes occurs in the Big Bend region of the gulf coast (fig. 2/4). Mangrove swamps replace salt marshes along southern coastal areas that generally are subject to low-energy waves. Mangroves are salt-tolerant trees that colonize shallow, subtropical marine and es- tuarine waters. Tropical storms commonly damage or destroy man- groves before they reach their maximum height (Odum and Mclvor, 1990), and most mangrove swamps are classified as scrub-shrub wetlands because the trees typically are less than 20 feet tall. Seagrass beds are colonies of several species of rooted vascu- lar plants that typically live totally submersed in saltwater. Most of Florida's seagrass beds are in Florida Bay at the southern tip of the State and in the Gulf of Mexico offshore from the Big Bend. In this report, only the shallowest zone of seagrass communities, in which shoal grass predominates, are considered to be wetlands; extensive seagrass beds below the intertidal zone are considered to be in deep- water habitats. HYDROLOGIC SETTING Many factors contribute to the abundance of wetlands in Florida, the most important of which are the low, flat terrain and plentiful rainfall. Most of the State's wetlands are in flat areas be- low 50 feet above sea level that extend from the coast inland for many miles (fig. 2A and 2C). Runoff and drainage in these wetlands are slow as a result of the low relief. The flat landscape and the imper- meable strata underlying wetland soils commonly result in lateral flow of water on or near the land surface. Some wetlands are drained by low-gradient stream systems, as in the upper St. Johns River basin, which has extensive freshwater marshes and where the aver- age velocity of the river is only 0.3 foot per second (Heath and Conover, 1981). Near the coast, water levels in freshwater wetlands along these streams are affected by tidal fluctuations. Close to the mouth of the streams, the transition from freshwater to saltwater causes major changes in the structure and composition of estuarine wetlands (Florida Department of Natural Resources, 1988). Except along the southeastern coast, the land slopes gradually into the Gulf of Mexico and Atlantic Ocean. The shallow water off- shore diminishes the energy of incoming waves, resulting in small, low-energy breakers onshore. Two areas on the gulf coast receive low-wave energy favorable to the development of tidal marshes, seagrass beds, and mangrove swamps (fig. 2B). The near-zero wave- energy coastline from north of Tampa to St. Marks is a result of the shallow offshore waters and a protected location in Florida's Big Bend. One of few coastal areas in the world subject to so little wave action, this part of the coast has the second-largest area of seagrass beds in the Gulf of Mexico (Zieman and Zieman, 1989), large ar- eas of coastal marsh, and extensive hydric hammocks just landward of coastal salt marshes (Vince and others, 1989). Rainfall in Florida averages 53 inches per year and is greatest during the warm season from June through September. Southern Florida has a subtropical climate characterized by two seasons dry and rainy rather than by the four seasons typical of temperate climates to the north. As a result, wetlands in southern Florida are affected by greater extremes of hydrologic conditions than those in the rest of the State. Wet prairies, wet pine flatwoods, and scrub cypress forests that are saturated or inundated in the rainy season can be severely dehydrated in the dry season in late winter and early spring when rainfall is relatively low and temperatures and evapo- transpiration rates remain relatively high (Jordan, 1984). Opposite conditions exist in northern Florida, where flooding and replenishment of water in swamps and flood plains is greatest in the late winter and early spring. Winter evapotranspiration is substantially lower than that in southern Florida because tempera- tures are near or below freezing on many days and much of the vegetation is dormant. Summer rainfall exceeds winter rainfall in northern Florida, but the difference is not as great as in southern Florida because of a secondary rainfall peak in February and March. In adjacent States to the north, this secondary winter-spring peak is more pronounced and in some areas is the primary peak. Most of the drainage basins of the larger northern Florida rivers such as the Apalachicola, Choctawhatchee, Escambia, and Suwannee are in Georgia and Alabama. Therefore, rainfall patterns in those States have a significant effect on the hydrology of these rivers and their flood-plain wetlands. The broad flood plains of these rivers have topographic features and tree communities that have been shaped by wide fluctuations in river levels. During the annual flooding in late winter and early spring, water depths on the flood plain of 15- 20 feet are not unusual. However, in the rest of the year, these flood plains are mostly dry except for ponds, depressions, and sloughs that retain water year round. Southern Florida has a nearly freeze-free climate (fig. 2D). Wetlands along the southern coasts support plant species that gen- erally do not thrive in the cooler climate of northern Florida coasts (Odum and others, 1982). For example, mangroves are killed back by freezes, which are more common in northern Florida, and some seagrass species are better adapted to the warm waters of the south- ern coasts. Wetlands in southern Florida commonly are invaded by nonnative tropical species that alter native-species associations; two such nonnative species, melaleuca and Brazilian pepper, have be- come predominant in many southern Florida wetlands. The near absence of frost in southern Florida that enables some tropical spe- cies to thrive also limits the distribution of some temperate wetland species. Pond pine, several hollies, titis, some of the tupelos, many bottom-land hardwood tree species, and several species of marsh plants grow only in the central and northern regions of the State. Early travelers to southern Florida encountered a vast fresh- water marsh that covered most of the peninsula from Lake Okeechobee south. This wetland, now known as The Everglades, covered about 2.9 million acres and was predominantly peatland covered by tall sawgrass growing in shallow water. Associated plant communities included pond apple swamps south of the lake, sloughs with aquatic vegetation, wet prairies, tree islands, and mangrove swamps bordering Florida Bay. The Everglades was part of the larger Kissimmee-Lake Okeechobee-Everglades Basin, which extended as a single drainage basin from present-day Orlando to Florida Bay, about two-thirds the length of the Florida peninsula (fig. 3A). The Kissimmee River meandered across a 2-mile-wide flood plain south to Lake Okeechobee, a shallow water body of 470,000 acres. When the lake was full, water sometimes overflowed the southern rim into The Everglades. Water in The Everglades moved slowly to the south by sheet flow in what Douglas (1947) called the River of Grass. Much of the land was inundated during the rainy season in normal years, and, during years of heavy rains, all but the highest tree is- lands were flooded. During floods, water moved with enough force to cause tree islands to develop an alignment pattern parallel to the lines of surface-water flow (Parker, 1974). During the dry season, ground-water levels generally were close to the land surface, but during some years, severe drought lowered water levels well below the land surface and fires swept over the land, burning vegetation and peat. Seasonally varying flows of freshwater from The Ever- glades into Florida Bay had an important influence on the salinity of the bay and contributed to the productivity of coastal wetlands and fisheries. Significant drainage of The Everglades began in the early 1880's and continued through the 1960's. By the late 1920's, five canals connected Lake Okeechobee to the Atlantic Ocean. During the hurricanes of 1926 and 1928, Lake Okeechobee overflowed, killing thousands of people and destroying crops. In response to these disasters, a 38-foot-high dike was constructed around the southern shore of the lake, and canals were enlarged to increase drainage (Blake, 1980). The Central and Southern Florida Flood National Water Summary Wetland Resources: FLORIDA 157 Control Project of 1948 authorized construction of a complex drain- age and water-management system comprising canals, levees, pumps, and control structures. Lake Okeechobee and three water- conservation areas (WCA'S; fig. 35) became reservoirs for flood pro- tection during the wet season and for agricultural irrigation and recharge of ground water in urban wellfields during the dry season (Klein and others, 1975). Most of the 800,000 acres of the Ever- glades Agricultural Area was drained to grow sugar cane and other crops. About 50 percent of the original Everglades was eliminated by the early 1990's. The remaining 50 percent is preserved in WCA- 1 (Loxahatchee National Wildlife Refuge), WCA-2, wcA-3, and Everglades National Park, which was established in 1947 on 1.4 million acres at the southwestern end of the drainage basin. Alterations of The Everglades by drainage and development have had severe environmental consequences. About 40 percent of the water that originally flowed southward from Lake Okeechobee into The Everglades is now diverted westward to the Gulf of Mexico by the Caloosahatchee Canal and eastward to the Atlantic Ocean by the St. Lucie Canal (fig. 3B). Seawater intrusion into the surficial aquifer has occurred as far as 6 miles inland in some areas (VanArman and others, 1984). Lowered water tables have resulted in oxidation of drained peat and damaging peat fires that have low- 82° 80° 79° 28° 27° 26° 25° Drainage Basin Boundary-. <* «, Lucie R Predevelopment Everglades and associated wetlands 83° FLORIDA BAY 28" - 25 50 MILES 25 50 KILOMETERS 27 C EXPLANATION 2 Water Conservation Area (WCA) number Jf Direction of water flow 26° Figure 3. Drainage patterns and selected geographic features in the Everglades-Lake Okeechobee-Kissimmee River drainage basin before and after development. A, Predevelopment. B, Recent. (Sources: A, Parker, 1974; Davis, 1943. B, South Florida Water Management District, 1992.) 25° ^<0*'* ~7 82° 81 C 79° Drainage Basin Boundary-> \ St Lucie Canal Everglades Agricultural Area (EAA) Loxahatchee Wildlife Refuge 158 National Water Summary Wetland Resources: STATE SUMMARIES ered the land surface more than 5 feet in some agricultural areas (Davis, 1943; Duplaix, 1990). Using the WCA'S as reservoirs has re- sulted in conditions that are often too dry or too wet to maintain natural communities (McPherson, 1973). South of Lake Okeecho- bee, populations of wood storks and other wading birds decreased by almost 95 percent from 1870 to 1973 as a direct result of hydro- logic alterations (Crowder, 1974; Kushlan and others, 1975). Drain- age and land clearing have increased opportunities for exotic plants such as melaleuca to become established in dense stands that ex- clude native species. Water pumped into canals from agricultural lands can have high levels of phosphorus and other nutrients. As a result, sawgrass, which is adapted to a low-nutrient environment (Davis, 1991), is being replaced by cattails in the northern Ever- glades, particularly in WCA-2, where nutrient loading is a problem (South Florida Water Management District, 1992). The magnitude of environmental alterations of The Everglades has produced public concern and countermeasures to protect this significant wetland. The 570,000-acre Big Cypress National Pre- serve adjacent to Everglades National Park was established in 1974. The Everglades was designated a "Wetland of International Impor- tance" by the Federal Government. State and Federal agencies work- ing cooperatively have developed plans that call for acquisition of parts of Shark River Slough and the remaining Everglades east of Everglades National Park and reestablishment of water flows along historic flow paths. Preliminary plans also have been made to re- store the once-meandering Kissimmee River, which was reduced from 90 to 52 miles in length by channelization in the 1960's. The State, as part of the settlement of a lawsuit filed by the Federal Government, has agreed to enforce a plan to greatly reduce nutri- ent loading from the Everglades Agricultural Area. Federal legisla- tion has assured minimum flows to Everglades National Park, and attempts are being made to distribute water based on historic sea- sonal-flow models. However, as water-demand patterns in southern Florida become more complex, difficulties in providing water of the proper quantity and quality at the proper time to remaining natural areas of The Everglades will increase. Because of the extensive water-control system, water-management decisions have replaced natural events as the driving force controlling the function and evo- lution of The Everglades. TRENDS Wetlands covered more than one-half of Florida before devel- opment began (Hampson, 1984; Dahl, 1990). The Swamp Land Acts of the mid-1800's transferred 20.3 million acres of "swamp and overflowed" lands from Federal to State ownership (Shaw and Fredine, 1956), and that was the acreage assumed by the FWS Na- tional Wetlands Inventory for Florida's predevelopment (1780's) wetlands (Dahl, 1990). In 1906, the U.S. Department of Agricul- ture conducted the first inventory of the Nation's wetlands. The sur- vey reported 19.8 million acres of wetlands in Florida excluding coastal lands overflowed by tidewater, indicating that wetland losses in Florida probably were minimal before the 1900's (Shaw and Fredine, 1956). Wetland losses were greater in the early 1900's than in the period between 1930 and the mid-1950's owing to the lack of funds available for drainage projects during the Great Depression and World War II. By the mid-1950's, 15.3 million acres of wetlands remained (Shaw and Fredine, 1956). Most of the losses were due to agricultural drainage in the St. Johns River valley, on the lower east coast, in the Kissimmee River and Everglades region around Lake Okeechobee, and scattered in the west-central peninsula (Gray and others, 1924; U.S. Bureau of the Census. 1952; Blake, 1980). Be- tween the mid-1950's and mid-1970's, wetland losses were extensive in The Everglades, where 1.5 million acres of primarily wet prai- ries and freshwater marshes were drained for agriculture and real estate development (Odum and Brown, 1977). Moderate drainage was conducted from the mid- to late 1950's in northern Florida to enhance pine timber production. The rate of wetland losses for all of Florida slowed to 26,000 acres annually between the mid-1970's and mid-1980s; losses due to agriculture still were greatest, and losses to urbanization were second in importance (Prayer and Hefner, 1991). Recent estimates of the wetland acreage remaining in Florida differ by almost 3 million acres; most of the difference is in the forested-wetland category. Wetlands delineated in figure 2A and reported by the FWS total 11 million acres (Prayer and Hefner, 1991). The Florida Game and Fresh Water Fish Commission, using 1985- 89 Landsat Thematic Mapper imagery, estimated that about 8.2 mil- lion acres of wetlands remain (Kautz, 1991). Hampson (1984) esti- mated that about 8.3 million acres of wetlands existed in Florida in 1973. These two estimates are lower than the FWS estimate prob- ably because they exclude most of Florida's wet pine flatwoods, one of the most common natural communities in the State. The Game and Fresh Water Fish Commission estimate also excluded some mixed-hardwood wetlands in areas where they could not be easily distinguished from upland hardwoods (J.M. Hefner, U.S. Fish and Wildlife Service, written commun., 1993). Wetlands regulations and legislation in effect today generally allow wetlands destruction only when mitigated by wetlands en- hancement, preservation, or creation. The effectiveness of these measures in slowing wetland loss is currently under evaluation (Prayer and Hefner, 1991). A recent report on the success of miti- gation indicated that the ecological success rate for completed projects was low for one-third of all permitted projects, the re- quired mitigation had never been attempted (Florida Department of Environmental Regulation, 1991). CONSERVATION Many government agencies and private organizations partici- pate in wetlands conservation in Florida. The most active agencies and organizations and some of their activities are listed in table 1. Federal wetland activities. Development activities in Florida wetlands are regulated by several Federal statutory prohibitions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Harbors Act; the 1972 Clean Water Act and amendments; the 1985 Food Security Act; the 1990 Food, Agriculture, Conservation, and Trade Act; the 1986 Emergency Wetlands Resources Act; and the 1972 Coastal Zone Management Act. Section 10 of the Rivers and Harbors Act gives the U.S. Army Corps of Engineers (Corps) authority to regulate certain activities in navigable waters. Regulated activities include diking, deepening, filling, excavating, and placing of structures. The related section 404 of the Clean Water Act is the most often-used Federal legislation protecting wetlands. Under section 404 provisions, the Corps issues permits regulating the discharge of dredged or fill material into wetlands. Permits are subject to review and possible veto by the U.S. Environmental Protection Agency (EPA), and the FWS has review and advisory roles. Section 401 of the Clean Water Act grants to States and eligible Indian Tribes the authority to approve, apply conditions to, or deny section 404 permit applications on the basis of a pro- posed activity's probable effects on the water quality of a wetland. Most farming, ranching, and silviculture activities are not sub- ject to section 404 regulation. However, the "Swampbuster" provi- sion of the 1985 Food Security Act and amendments in the 1990 Food, Agriculture, Conservation, and Trade Act discourage (through financial disincentives) the draining, filling, or other alteration of wetlands for agricultural use. The law allows exemptions from pen- alties in some cases, especially if the farmer agrees to restore the altered wetland or other wetlands that have been converted to agri- cultural use. The Wetlands Reserve Program of the 1990 Food, Agriculture, Conservation, and Trade Act authorizes the Federal Government to purchase conservation easements from landowners who agree to protect or restore wetlands. The Consolidated Farm National Water Summary Wetland Resources: FLORIDA 159 Service Agency (formerly the Agricultural Stabilization and Conser- unaffected wetlands, or wetlands creation. Pursuant to section vation Service) administers the Swampbuster provisions and Wet- 305(b) of the Clean Water Act, the Department of Environmental lands Reserve Program. The Natural Resources Conservation Protection submits to the ERA and the U.S. Congress a biennial as- Service (formerly the Soil Conservation Service) determines com- sessment of the State's surface-water quality, including that of wet- pliance with Swampbuster provisions and assists farmers in the iden- lands. The Department of Environmental Protection has general tification of wetlands and in the development of wetland protection, oversight authority for the five water-management districts, which restoration, or creation plans. have authority to levy local taxes and regulatory authority over iso- The 1986 Emergency Wetlands Resources Act and the 1972 lated wetlands within district boundaries. Authorization to use Coastal Zone Management Act and amendments encourage wetland wetlands that are part of sovereign submerged lands is required from protection through funding incentives. The Emergency Wetland the Department of Environmental Protection. These lands, which Resources Act requires States to address wetland protection in their lie under navigable waters, are held in trust for all the citizens of Statewide Comprehensive Outdoor Recreation Plans to qualify for Florida. The Department of Enviornmental Protection has desig- Federal funding for State recreational land; the National Park Ser- nated portions of these submerged lands as aquatic preserves, which vice provides guidance to States in developing the wetland compo- are carefully managed. nent of their plans. Coastal States that adopt coastal-zone manage- Since 1963, the State of Florida has administered land-acqui- ment programs and plans approved by the National Oceanic and sition programs that have preserved many wetlands and areas adja- Atmospheric Administration are eligible for Federal funding and cent to water bodies. Much of the land purchased for preservation, technical assistance through the Coastal Zone Management Act. as well as parks and other State-owned properties, is managed by State wetland activities. The Department of Environmental the Department of Environmental Protection; however, a substan- Protection is the principal State agency that issues permits for de- tial amount of publicly owned wetlands are managed by the water- velopment activities in wetlands. The Henderson Wetlands Act of management districts, the Game and Fresh Water Fish Commission, 1984 gave the Department of Environmental Regulation (now called and the Division of Forestry. Historically, land-management pro- the Department of Environmental Protection) expanded jurisdiction grams were designed for recreation, to develop specific resources over the issuance of permits for dredge-and-fill activities affecting such as timber, or to favor a few important game animals or endan- wetlands. The Department of Environmental Protection evaluates gered species. Partly as a result of citizen input and involvement, the potential effects on wetlands before granting permits and seeks ecosystem-management techniques such as prescribed burning are mitigation of unavoidable losses by enhancement, preservation of now widely used to maintain the natural character of wetlands and other ecological communities. Since the early 1970 s, ecosystem Table 1. Selected wetland-related activities of government maintenance as a land-management goal has gained favor in Florida agencies and private organizations in Florida, 1993 as the best strategy to ensure long-term protection of plant and _, . . . , _, animal species as well as sustainable resources for people. [Source: Classification of activities is generalized from information provided n . , ,, , , , ,. . . ^,, ., , ^ by agencies and organizations. ., agency or organization participates in Regional, county, and local wetland activities. Florida s Com- wetland-related activity;..., agency or organization does not participate in prehensive Planning Act of 1985, administered by the Department wetland-related activity. MAN, management; REG, regulation; R&C, restora- of Community Affairs, requires local governments to produce long- tion and creation; LAN, land acquisition; R&D, research and data collection; e lans for the development and conservation of resources. D&l, delineation and inventory _.,".,, . . . . , , ,- ., , Policies for wetlands protection are required elements of all plans. T Some city and county governments have strong regulatory or land- ^ <$l? <^ ^ <$& <^ acquisition programs that provide wetlands protection beyond that which is required by the State. Others, particularly in the largely FEDERAL rural northern part of the State, are less able to develop strong lo- Department of Agriculture ca] protection programs owing to funding limitations; thus, the State Consolidated Farm Service Agency........................... . and water.mana ement districts have the largest roles in wetland Forest Service.................................................................. ... Natural Resources Conservation Service ................ . . . . protection in those areas. Department of Commerce Private wetland activities. Private organizations in Florida National Oceanic and have important roles as advocates of wetland conservation and pro- Atmospheric Administration ........................................ tection. Florida has many private-interest groups that keep the public Department of Defense informed on wetland issues, organize citizen networks, and lobby MSrCy0resereatiSnnseerS "" -"--" --" for wetland-protection measures. The National Audubon Society, Department of the |nterj """""""""""'""""""""""""" jne Nature Conservancy, and the Trust for Public Lands have pur- Fish and Wildlife Service.............................................. chased wetlands in Florida for preservation. Some of these lands Geological Survey .......................................................... have been transferred to State or Federal ownership; others are pre- National Biological Service ......................................... served in private ownership, such as Corkscrew Swamp, an Audubon ES±^[pSSn-A-ge;cy:::::::::: ' . ' ' : : sanctuary.Othergroups,suchasrheFloridaWildlifeFederationand STATE the Sierra Club, conduct wetland-protection activities that include Department of Agriculture and Consumer programs to educate the public about wetland issues. Services Division of Forestry ........................................................ Department of Community Affairs.................................. .. .. ... .. ... References Cited Department of Environmental Protection..................... AU u «?/- JTT T-,/^ mnn r>- n * A A A Game and Fresh Water Fish Commission ..................... . . . . Abrahamson, W.G., and Hartnett, D.C., 1990, Pine flatwoods and dry prai- University of Florida Center for Wetlands .................... . ries-'" Myers - R-L" and Ewel- JJ" eds" Ecosystems of Florida: Or- OtherState university programs..................................... lando- University of Central Florida Press, p. 103-149. REGIONAL, COUNTY, AND LOCAL Blake, N.M., 1980, Land into water, water into land A history of water Water Management Districts .......................................... management in Florida: Tallahassee, University Presses of Florida, Regional Planning Councils ............................................. ... 344 p. Some County and City Governments ............................. Carlton, J.M., 1977, A survey of selected coastal vegetation communities PRIVATE ORGANIZATIONS of Florida: Florida Department of Natural Resources, Florida Marine National Audubon Society ............................................... Research Publication 30, 40 p. The Nature Conservancy.................................................. Conway, McKinley, and Listen, L.L., eds., 1990, The weather handbook: Trust for Public Lands........................................................ ... ... Norcross, Ga., Conway Data, Inc., 548 p. 160 National Water Summary Wetland Resources: STATE SUMMARIES Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS -79/31, 131 p. Crowder, J.P., 1974, Some perspectives on the status of aquatic wading birds in South Florida: U.S. Bureau of Sport Fisheries and Wildlife Report PB-231 216, 12 p. Dahl, T.E., 1990, Wetlands Losses in the United States, 1780's to 1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 13 p. Davis, J.H., 1943. The natural features of southern Florida: The Florida Geological Survey Bulletin 25, 311 p. Davis, S.M., 1991, Sawgrass and cattail nutrient flux Leaf turnover, de- composition, and nutrient flux of sawgrass and cattail in the Ever- glades: Aquatic Botany, v. 40, p. 203-224. Dierberg, F.E., and Brezonik, P.L., 1984, The effect of wastewater on the surface water and groundwater quality of cypress domes, in Ewel, K.C., and Odum, J.T., eds., Cypress Swamps: Gainesville, University Presses of Florida, p. 83-101. Douglas, M.S., 1947, The Everglades River of grass: New \brk, Rhinehart, 406 p. Duplaix, Nicole, 1990, South Florida water Paying the price: National Geographic, v. 178, no. 1, p. 89-113. Ewel, K.C., 1990, Swamps, in Myers, R.L.. and Ewel, J.J., eds., Ecosys- tems of Florida: Orlando, University of Central Florida Press, p. 281- 322. Fernald, E.A., ed., 1981, Atlas of Florida: Tallahassee, The Florida State University Foundation, Inc., 276 p. Florida Department of Environmental Regulation, 1991, Report on the ef- fectiveness of permitted mitigation: Tallahassee. Florida Department of Environmental Regulation, 59 p. Florida Department of Natural Resources, 1988, Wetlands in Florida An addendum to Florida's Comprehensive Outdoor Recreation Plan: Tal- lahassee, Florida Department of Natural Resources, 91 p. Florida Natural Areas Inventory and Division of State Lands, 1990, Guide to the natural communities of Florida: Tallahassee, Florida Depart- ment of Natural Resources, 111 p. Prayer. W.E., and Hefner, J.M., 1991, Florida wetlands Status and trends, 1970's to 1980's: Atlanta, U.S. Fish and Wildlife Service, 31 p. Gray, L.C., Baker, O.E., Marschner, F.J., and Weitz, B.O., 1924, The utili- zation of our lands for crops, pasture and forests, in U.S. Department of Agriculture, Agriculture yearbook 1923: Washington, D.C., U.S. Government Printing Office, 1,284 p. Grow, Gerald, 1989, Florida parks A guide to camping in nature (4th ed.): Tallahassee, Fla., Longleaf Publications, 260 p. Hampson, P.S., 1984, Wetlands in Florida: Tallahassee, Florida Bureau of Geology Map Series 109, scale 1:2,000,000. Heath, R.C., and Conover, C.S., 1981, Hydrologic almanac of Florida: U.S. Geological Survey Open-File Report 81-1107, 239 p. Jordan, C.L., 1984, Florida's weather and climate Implications for water, in Fernald, E.A., and Patton, D.J., eds.. Water resources atlas of Florida: Tallahassee, Florida State University, p. 18-35. Kautz, R.S., 1991, Space age habitat mapping: Florida Wildlife, v. 45, no. 73, p. 30-33. Klein, Howard, Armbruster, J.T., McPherson, B.F., and Freiberger, J.J., 1975, Water and the south Florida environment: U.S. Geological Sur- vey Water-Resources Investigations 24-75, 165 p. Kushlan, J.A., 1990, Freshwater marshes, in Myers, R.L., and Ewel, J.J., Ecosystems of Florida: Orlando. University of Central Florida Press, p. 324-363. Kushlan, J.A., Ogden, J.C., and Higer, A.L., 1975, Relation of water level and fish availability to wood stork reproduction in southern Ever- glades, Florida: U.S. Geological Survey Open-File Report 75-434, 56 p. Leitman, H.M., Sohm, J.E., and Franklin, M.A., 1984, Wetland hydrology and tree distribution of the Apalachicola River flood plain, Florida: U.S. Geological Survey Water-Supply Paper 2196, 52 p. McPherson, B.F., 1973, Vegetation in relation to water depth in Conserva- tion Area 3, Florida: U.S. Geological Survey Open-File Report 73- 0173, 60 p. ____1979, Land cover map of the Green Swamp area, Central Florida: U.S. Geological Survey Miscellaneous Investigations Series Map I- 1134, scale 1:63,360. Odum, H.T., and Brown, Mark, eds., 1977, Carrying capacity for man and nature in South Florida: Gainesville, Fla., National Park Service and University of Florida Center for Wetlands cooperative publication, 886 p. Odum, W.E., and Mclvor, C.C., 1990, Mangroves, in Myers, R.L., and Ewel, J.J., Ecosystems of Florida: Orlando, University of Central Florida Press, p. 517-548. Odum, W.E., Mclvor, C.C., and Smith, T.J., III, 1982, The ecology of the mangroves of South Florida A community profile: U.S. Fish and Wildlife Service Report FWS/OBS-81/24. 144 p. Palik, T.F., and Kunneke, J.T., 1984, Northwestern Florida ecological char- acterization An ecological atlas: U.S. Fish and Wildlife Service Report FWS/OBS-82/47.1, 302 p. Parker, G.G., 1974, Hydrology of the pre-drainage system of the Everglades in South Florida, in Gleason, P.J., ed., Environments of South Florida Present and past: Miami, Fla., Miami Geological Society, Memoir 2. p. 718-727. Shaw, S.P., and Fredine, C.G., 1956, Wetlands of the United States Their extent and their value to waterfowl and other wildlife: U.S. Fish and Wildlife Service Circular 39, 67 p., 1 map. South Florida Water Management District, 1992, Surface water improve- ment and management plan for the Everglades: West Palm Beach, South Florida Water Management District Support Information Docu- ment, 472 p. Tiner, R.W., Jr., 1984, Wetlands of the United States Current status and recent trends: Washington, D.C., U.S. Fish and Wildlife Service, 59 p. U.S. Bureau of the Census, 1952, United States census of agriculture, 1950, v. 4 Drainage of agricultural lands: Washington, D.C., U.S. Gov- ernment Printing Office, 307 p. U.S. Soil Conservation Service. 1989. Twenty-six ecological communities of Florida (revised ed.): Gainesville, Florida Chapter Soil and Water Conservation Society, 286 p. VanArman, Joel; Nealon, Dennis; Burns, Scott; Jones, Brad; Smith, Lisa; MacVicar, Thomas; Yamsura, Margaret; Federico, Anthony; Bucca, Jane; Knapp, Michael; and Gleason, Patrick, 1984, South Florida Water Management District, in Fernald, E.A., and Patton, D.J., eds., Water resources atlas of Florida: Tallahassee, Florida State University, p. 138-157. Vince, S.W., Humphrey, S.R., and Simons, R.W., 1989, The ecology of hydric hammocks A community profile: U.S. Fish and Wildlife Service Biological Report 85(7.26), 81 p. Wharton, C.H.; Odum, H.T.; Ewel, K.C.; Duever, M.J.; Lugo, Ariel; Boyt, Rene; Bartholemew, J.; DeBellevue, E.B.; Brown, S.; Brown, M.; and Duever, L.C., 1977, Forested wetlands of Florida Their management and use: Gainesville, University of Florida, 348 p. Zieman, J.C., and Zieman, R.T., 1989, The ecology of the seagrass mead- ows of the west coast of Florida A community profile: U.S. Fish and Wildlife Service Biological Report 85(7.25), 155 p. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Survey, 227 N. Bronough St., Suite 3015, Tallahassee, FL 32301; Regional Wetland Coordinator, U.S. Fish and Wildlife Service, 1875 Century Build- ing, Suite 200, Atlanta, GA 30345 Prepared by Melanie R. Darst, Helen M. Light, and Benjamin F. McPherson, U.S. Geological Survey U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources 161 Georgia Wetland Resources VJeorgia has more than 7.7 million acres of wetlands about one- fifth of the surface area of the State (Hefner and others, 1994.) Most wetlands in Georgia have been adversely affected by human activi- ties, but coastal salt marshes and a large area of preserved wilder- ness in the Okefenokee Swamp remain relatively undisturbed. One of the few remaining old-growth cypress-tupelo forests in the South- east is on the lower Altamaha River flood plain (fig. 1). Wetlands provide many economic and ecological benefits. Flood-plain wetlands dissipate the energy of floods, reduce erosion, and stabilize the streamside environment. Wetlands filter water entering rivers and coastal marsh systems, removing sediment and pollutants. Annual flooding moves leaf litter and other terrestrial organic detritus from the flood plain into the main channel, provid- ing a primary source of food for stream and estuarine organisms. Wetlands bordering many streams in Georgia are important habi- tat corridors for wildlife. Amid the pine plantations and farms cov- ering most of the uplands, wetland corridors connect areas that provide food, shelter, and water for many species of animals. During low-water periods, flood-plain ponds and backwaters contribute to biological diversity in stream ecosystems by providing still-water habitats for fish, amphibians, reptiles, and aquatic invertebrates. Biological productivity in estuarine emergent wetlands is higher than on most agricultural lands (Teal and Teal, 1969). Such coastal wetlands are essential to the life cycles of many commercially har- vested species such as clams, shrimp, blue crab, and mullet (Tiner, 1984). In addition to their ability to remove undesirable chemicals and support wildlife, wetlands are valued by tourists and Georgians for their recreational uses and natural beauty. Sidney Lanier, a native of Georgia, described a vista of coastal marshland in his poem "The Marshes of Glynn": A league and a league of marsh-grass, waist-high, broad in the blade, Green, and all of a height, and unflecked with a light or a shade, Stretch leisurely off. in a pleasant plain, To the terminal blue of the main. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deep- water habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and oth- ers, 1979). The distribution of wetlands and deepwater habitats in Georgia is shown in figure 2A; only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Georgia are described below. System Palustrine. Lacustrine . Figure 1 . Old-growth gum-cypress forest on the Altamaha River flood plain. (Photograph by C.H. Wharton, Clayton, Ca.) Wetland description . Nontidal and tidal-freshwater wetlands in which vegetation is predominantly trees (forested wet- lands); shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted herba- ceous plants (persistent- and nonpersistent- emergent wetlands); or submersed and (or) floating plants (aquatic beds). Also, intermit- tently to permanently flooded open-water bod- ies of less than 20 acres in which water is less than 6.6 feet deep. . Nontidal and tidal-freshwater wetlands within an intermittently to permanently flooded lake or reservoir larger than 20 acres and (or) deeper than 6.6 feet. Vegetation, when present, is pre- dominantly nonpersistent emergent plants (non- persistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds), or both. . Nontidal and tidal-freshwater wetlands within a channel. Vegetation, when present, is same as in the Lacustrine System. . Tidal wetlands in low-wave-energy environments where the salinity of the water is greater than 0.5 part per thousand (ppt) and is variable owing to evaporation and the mixing of seawater and freshwater. . Tidal wetlands that are exposed to waves and cur- rents of the open ocean and to water having a salinity greater than 30 ppt. About 95 percent of Georgia's wetlands are palustrine. Estua- rine and marine wetlands comprise approximately 4 percent of the State's wetland acreage. Lacustrine and riverine wetlands are not addressed in this report because they constitute a relatively small part of the State's wetlands and are generally fringe areas between palustrine wetlands and deepwater habitats. Riverine. Estuarine. Marine. 162 National Water Summary Wetland Resources: STATE SUMMARIES Palustrine System. Forested wetlands constitute about 83 percent of all palustrine wetlands in Georgia (J.M. Hefner, U.S. Fish and Wildlife Service, oral commun., 1993). Large tracts of second- growth bottom-land hardwoods and tupelo-cypress forests exist along many Georgia rivers. Most of these rivers can be character- ized as either alluvial or blackwater streams. Alluvial streams such as the Altamaha, Oconee, Ocmulgee, Savannah, Flint, and Chattahoochee Rivers carry large amounts of sediment. Their flood plains have mineral soils and diverse topo- graphic features such as flats, ridges, backswamps, and oxbow lakes. Flats and ridges support forests of mixed bottom-land hardwood species; backswamps generally have canopies of tupelo and cypress. The alluvial river with the greatest average discharge in Georgia is the Altamaha River, which has a flood plain 3- to 5-miles wide along some reaches. The Altamaha River drainage basin includes about one-fourth of the State and extends from Atlanta to the Atlantic coast. The basin has many small streams and two large rivers, the Oconee and Ocmulgee Rivers, which join to form the Altamaha River. Blackwater streams such as the Ogcechee, Satilla, and St. Marys Rivers generally contain water that is dark or tea colored because of a high content of tannins and other organic acids. Black- water streams usually have low velocities and carry little sediment. Their flood plains have less topographic relief and are usually nar- rower than flood plains of alluvial streams. Blackwater river flood- plain wetlands have canopies of tupelo, cypress, and other tree spe- cies tolerant of wet organic soils. Forested palustrine wetlands in Georgia that are not associated with stream systems include cypress domes, gum swamps, limesinks, Carolina bays, wet pine flatwoods, and hydric hammocks. Isolated cypress swamps and cypress domes occur primarily below the Fall Line (fig. 2B), the area of transition between the higher topographic relief of the piedmont to the north and the flatter to- pography of the coastal plain to the south. Cypress domes are cir- cular depressional wetlands forested by pond cypress trees that grow taller in the center of the wetland and thus create a dome-shaped canopy. Gum swamps are depressional wetlands in which swamp Southern Blue Ridge Section Southern Valley and Ridge Section 50 KILOMETERS WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown ^^H Predominantly wetland Predominantly deepwater habitat Dams (Storage capacity at least 5,000 acre/feet) Figure 2. Wetland distribution in Georgia and physiography of the State. A, Distribution of wetlands and deepwater habitats. B, Physio- graphy. (Sources: A, If. Dahl, U.S. Fish and Wildlife Service, unpub. data, 1991. B, Physiographic divisions from Clark and Zisa, 1976; landforms data from EROS Data Center.) National Water Summary Wetland Resources: GEORGIA 163 tupelo is the predominant tree. The northwestern part of the Okefenokee Swamp contains large tracts of gum swamp. Limesinks are depressional wetlands formed by the dissolution or collapse of underlying limestone. Limesinks differ widely in size, depth, and average length of time they are inundated or have saturated soils. The Swamp of Toa in southwestern Georgia is the most extensive limesink area in Georgia. Many of the limesinks are connected to ground-water aquifers and serve as recharge areas (Kalla and others, 1993). The Swamp of Toa is a mosaic of wetland and upland habi- tats that support rare plant and animal species such as chaffseed and blind cave salamander. Limesink depressions called sagponds are distinctive wetlands because they occur in mountainous north- western Georgia yet contain relict populations of lowland plants (Wharton, 1977). Sagponds differ in wetness from intermittently to permanently flooded. Carolina bays, a wetland type unique to the Southeastern United States coastal plain, are oval depressions that have acidic, commonly peaty soils (Wharton, 1977). The predomi- nant vegetation in these wetlands generally is leathery-leaved, ev- ergreen, or semideciduous shrubs like fetterbush, titi, and zenobia. More than 1,000 Carolina bays, occupying an area of about 250,000 acres, have been mapped in Georgia (Wharton, 1977). Wet pine flatwoods forested by old-growth slash or pond pine grow mostly in southeastern Georgia and have soils that are saturated during part of the growing season. Small patches of wet pine flatwoods can be interspersed among upland pine forests. Hydric hammocks are a rare wetland type that exists in some areas of coastal Georgia. Semi- evergreen bottom-land hardwood species such as swamp laurel oak are the predominant vegetation (Vince and others, 1989). Approximately 17 percent of Georgia's palustrine wetlands are nonforested (J.M. Hefner, U.S. Fish and Wildlife Service, oral commun., 1993). These nonforested wetlands are primarily fresh marshes associated with streams or isolated water bodies. In these wetlands, emergent vegetation such as giant cutgrass, wild rice, pickerelweed, and arrow arum are the predominant plants (Wharton, 1978). More than 20 percent of the Okefenokee Swamp is emergent marshes and aquatic beds. Herb bogs occur on sloping ground or in slight depressions in pine uplands (Wharton, 1978) and have abundant herbaceous plants, including orchids, insectivorous plants (such as pitcher plants), and a variety of wildflowers, but have few or no trees. The absence of a tree canopy in herb bogs might be due to the high frequency of fires and the nutrient-poor, shallow soils and underlying hardpan clays. Estuarine and Marine Systems. Most of Georgia's coastal wetlands are located in estuaries at the mouths of rivers. Salt marshes in which the predominant emergent plant species is smooth cordgrass are the most common estuarine wetlands (Wiegert and Freeman, 1990). Smooth cordgrass marshes are flooded daily by tides and are exposed to mostly low-energy waves. These marshes fringe the sounds that are between the mainland and offshore bar- rier islands. The largest area of estuarine wetlands in Georgia sur- rounds St. Andrews and St. Simons Sounds. This wetland has more than 110,000 acres of salt marshes (Field and others, 1991). Tidal flats are estuarine wetlands that are regularly exposed and flooded by tides. These flats generally are devoid of rooted vegetation but are important foraging areas for shorebirds. Georgia's marine wet- lands comprise the intertidal zone of barrier-island ocean beaches. HYDROLOGIC SETTING The abundance of wetlands in Georgia is primarily due to high rainfall statewide and relatively flat topography in the southern part of the State. Annual rainfall in the State averages about 50 inches (Carter and Hopkins, 1986). The largest streams in Georgia origi- nate in or near the mountainous northeastern part of the State, which has high precipitation and runoff. Flood-plain wetlands develop along stream borders in areas of low topographic relief, where stream velocities are slower. Width of flood plains along rivers and the occurrence of isolated depressional wetlands between rivers in- crease as the land flattens toward the coast. Coastal areas have the greatest acreage of wetlands (fig. 2A). The great diversity of Georgia wetlands is a result of the State's diverse physiography. Clark and Zisa (1976) divided Georgia into six physiographic sections (fig. 2B). Three of the sections, the Cumberland Plateau, Southern Valley and Ridge, and Southern Blue Ridge, are in northern Georgia and are the areas with the greatest topographic relief. Many of the wetlands in these sections are moun- tain seeps and bogs that are too small and scattered to be shown in figure 2A. Narrow wetlands border some streams. Depressional wetlands are rare, except for sagponds, which exist in some areas of the Coosa River Valley of the Southern Valley and Ridge Section and in the Cumberland Plateau Section. The Southern Piedmont Section of Georgia lies between the more mountainous sections and the coastal plain. This section has a broad zone of gently rolling hills that are geologically similar to the Blue Ridge Mountains but have less relief as a result of stream erosion (Wharton, 1978). Flood plains are wider and better devel- oped in the Southern Piedmont Section than in the more mountain- ous Southern Blue Ridge and Southern Valley and Ridge Sections to the north. Some depressional wetlands such as gum swamps ex- ist in the Southern Piedmont Section, but cypress domes are ab- sent. The two physiographic sections that form the coastal plain in southern Georgia are the East Gulf Coastal Plain and Sea Island Sections (fig. 2B). These sections lie southeast of the Fall Line and include more than one-half the land area of Georgia. Topographic relief is lower, runoff is slower, and depressional features are more common in these two sections than in the Southern Piedmont Sec- tion. Streams in the East Gulf Coastal Plain Section in southwest- ern Georgia trend north-south and drain into the Gulf of Mexico. Karst topography, which is created by dissolution of porous lime- stone near the land surface, prevails in parts of this section and is characterized by numerous limesinks and other depressional fea- tures. The Sea Island Section contains the greatest extent of wetlands in Georgia. Flood-plain wetlands along rivers are more extensive in this section than in any other physiographic section. A schematic cross section of an alluvial flood plain in Georgia is shown in fig- ure 3. The topographic features shown in the cross section were formed by deposition and removal of sediments by flowing water. Most areas of an active flood plain are flooded at least annually. The driest part of a flood plain is generally the natural levee adjacent to the river. Levees and flats, which drain rapidly after floods recede, are covered by canopies of bottom-land hardwoods such as live oak, water oak, sweetgum, overcup oak, water hickory, and swamp laurel oak. The wettest part of the flood plain, the backswamp, commonly is farthest from the river and adjacent to the uplands. Backswamps generally hold water after floods recede and are sometimes perma- nently saturated. Tupelo gum and cypress are the dominant trees because of their ability to tolerate long periods of flooding. Rivers in the Sea Island Section flow southeastward toward the Atlantic coast, with the exception of the Suwanee River, which flows into the Gulf of Mexico. In their lower reaches, tidal freshwater swamps are flooded by a combination of tidal fluctuations and high seasonal freshwater flows. Estuaries at the river mouths are fringed by extensive marshes. Georgia's concave coastline, situated between the jutting Florida peninsula to the south and the outward-curving South Carolina coastline to the north, provides coastal wetlands in this area some protection from tropical storms. A series of large barrier islands protects estuaries from high-energy waves and pro- vides shallowly inundated shorelines for the development of salt marshes. Tidal ranges are greater on the Georgia coast than along 164 National Water Summary Wetland Resources: STATE SUMMARIES the other Southeastern Atlantic coastal States. This large tidal range (6-9 feet) influences both the inland extent and topography of salt marshes (Wiegert and Freeman, 1990). The Sea Island Section also contains the largest acreages of isolated inland wetlands such as wet pine flatwoods, cypress swamps, gum swamps, and Carolina bays. Land-surface slopes are gentle in many areas within this section, and ground water is com- monly near the land surface. Typically, there is a hardpan layer in the subsurface soil that prevents rapid infiltration during rainy pe- riods, creating seasonally wet soils. During periods of little rain- fall, these same areas can be very dry. Plants adapted to a wide range of moisture conditions, such as gallberry and saw palmetto, are common in these seasonally wet areas. The Okefenokee Swamp, located in the southern part of the Sea Island Section (fig. 2B), covers approximately 440,000 acres in Georgia and is one of the largest freshwater wetlands in the United States. The swamp is a unique area containing a mosaic of emer- gent marshes, aquatic beds, forested and scrub-shrub wetlands, and forested uplands. The Okefenokee Swamp is located on a large ter- race that once might have been a shallow marine lagoon. When sea level declined, the terrace was isolated by a sand ridge along the eastern edge. The swamp ecosystem appears to have developed in the depression within the last 7,000 years (Laerm and Freeman, 1986). The swamp has few inflowing streams and, therefore, pri- marily depends on rainfall for water (Rykiel, 1984). Headwaters of the Suwannee and St. Marys Rivers are in the swamp. Water depths average about 2 feet over an uneven layer of peat composed of plant material that has accumulated over thousands of years. Imperme- able sediments underlying the peat keep most of the water from percolating into the ground. In severe drought, fires can burn the exposed peat, lowering the elevation of the swamp floor. Major fires probably burn large areas of the Okefenokee Swamp every 25 to 30 years (I/lar, 1984a). When normal hydrologic con- ditions return, the swamp floor is again inundated, and those areas where the peat was reduced hold deeper water in which aquatic plants such as water lilies grow. If fires are suppressed, swamp-floor levels can become high enough to support other types of wetlands such as an emergent marsh vegetated by maidencane, sedges, iris, and other plants. Accumulated plant material contributes to the buildup of peat until trees like red maple can grow or until fire again reduces the amount of peat on the floor of the swamp. The Okefenokee Swamp provides habitat for 36 species offish, 37 species of amphibians, 66 species of reptiles, and 48 species of mammals (Laerm and others. 1984). Among the inhabitants of the swamp are rare animal and plant species such as round-tailed musk- rat, sandhill crane, woodstork, and hooded pitcher plants. A reported 232 species of birds inhabit in the swamp during some part of the year; 120 of these species are permanent residents (Sanders, 1987). The Okefenokee Swamp was preserved by its own inhospitable- ness for many years. In the 1890's a canal was dug through the ridge on the eastern border to drain the swamp for logging and develop- ment. Drainage was unsuccessful, but eventually about 90 percent of the marketable cypress was removed (Izlar, 1984b). Some pio- neers managed to establish homesites in the swamp, but it was a place where only a few could make a living. The Okefenokee Na- tional Wildlife Refuge, created in 1937, includes approximately 85 percent of the swamp. After devastating fires in the 1950's, an earthern dam, or sill, was built on the Suwannee River to raise water levels in the swamp. This sill has affected water levels over approxi- mately one-fourth of the swamp area. Since the installation of the sill, scientific studies have clarified the role of natural fire in reju- venating the swamp, and wildlife managers are now considering allowing the sill to degenerate over time (Yin and Brook, 1992). TRENDS The FWS National Wetlands Inventory recently reported that Georgia had about 7.7 million acres of wetlands as of the 1980's (Hefner and others, 1994). This estimate was based on the results of a sampling procedure that used aerial photography. Another es- timate, based on satellite imagery, classified approximately 4.3 mil- lion acres in Georgia as wetland (J.R. Bozeman, Georgia Depart- ment of Natural Resources, written commun., 1992). The largest discrepancy between these surveys was in the estimates of palustrine forested wetlands (J.M. Hefner. U.S. Fish and Wildlife Service, oral commun., 1993). The discrepancies between estimates of wetland acreages could have resulted from differences in accuracy and reso- lution between aerial photography and satellite imagery and in in- terpretive techniques used for each method (Federal Geographic Data Committee, 1992). Because estimates of current wetland acreages in Georgia do not agree, estimates of losses are difficult to substantiate. Dahl (1990) reported wetland losses of approximately 23 percent for Georgia from the 1780's to I980's, the lowest percentage of loss among the Southeastern States. Wetland losses throughout the Southeast have been caused primarily by drainage for farming and forestry operations (Hefner and Brown, 1985). Palustrine forested wetlands along streams and isolated swamps of the coastal plain probably have been the most affected. Between the mid-1970's and mid-1980's, more than 100,000 acres of freshwater forested wetlands in Georgia were destroyed, mostly because of conversion to land uses such as agriculture (Dahl and others, 1991). Nearly 500,000 acres of palustrine forested wetlands were converted during the same time period to scrub-shrub or emergent freshwater wetlands (Hefner and others, 1994). Loss of estuarine marshes has slowed since 1970 when Georgia began protecting those wetlands from development. EXPLANATION High water Low water | Forest vegetation Figure 3. Schematic cross section of an alluvial river flood plain in Georgia. National Water Summary Wetland Resources: GEORGIA 165 CONSERVATION Many government agencies and private organizations partici- pate in wetland conservation in Georgia. The most active agencies and organizations and some of their activities are listed in table 1. Federal wetland activities. Development activities in Geor- gia wetlands are regulated by several Federal statutory prohibitions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Har- bors Act; the 1972 Clean Water Act and amendments; the 1985 Food Security Act; the 1990 Food, Agriculture, Conservation, and Trade Act; the 1986 Emergency Wetlands Resources Act; and the 1972 Coastal Zone Management Act. Section 10 of the Rivers and Harbors Act gives the U.S. Army Corps of Engineers (Corps) authority to regulate certain activities in navigable waters. Regulated activities include diking, deepening, filling, excavating, and placing of structures. The related section 404 of the Clean Water Act is the most often-used Federal legislation protecting wetlands. Under section 404 provisions, the Corps issues permits regulating the discharge of dredged or fill material into wetlands. Permits are subject to review and possible veto by the U.S. Environmental Protection Agency, and the FWS has review and ad- visory roles. Section 401 of the Clean Water Act grants to States and eligible Indian Tribes the authority to approve, apply conditions to, or deny section 404 permit applications on the basis of a pro- Table 1 . Selected wetland-related activities of government agencies and private organizations in Georgia, 1993 [Source: Classification of activities is generalized from information provided by agencies and organizations. , agency or organization participates in wetland-related activity;..., agency or organization does not participate in wetland-related activity. MAN, management; REG, regulation; R&C, resto- ration and creation; LAN, land acquisition; R&D, research and data collec- tion; D&l, delineation and inventory] Agency or organization FEDERAL Department of Agriculture Consolidated Farm Service Agency........... Forest Service ................................................. Natural Resources Conservation Service Department of Commerce National Oceanic and Atmospheric Administration ........................ Department of Defense Army Corps of Engineers .............................. Military reservations ..................................... Department of the Interior Fish and Wildlife Service .............................. Geological Survey.......................................... National Biological Service ......................... National Park Service ................................... Environmental Protection Agency.................. STATE Department of Community Affairs.................. Department of Natural Resources Coastal Resources Division ......................... Environmental Protection Division ............. Game and Fish Division ................................. Parks, Recreation, and Historic Sites Division ................................... Department of Transportation......................... Georgia Forestry Commission ......................... REGIONAL, COUNTY, AND LOCAL Regional Development Centers....................... Some county and city governments .............. PRIVATE ORGANIZATIONS The Nature Conservancy of Georgia ............. Georgia Wildlife Federation............................. Trust for Public Lands ........................................ posed activity's probable effects on the water quality of a wetland. Most farming, ranching, and silviculture activities are not sub- ject to section 404 regulation. However, the "Swampbuster" provi- sion of the 1985 Food Security Act and amendments in the 1990 Food, Agriculture, Conservation, and Trade Act discourage (through financial disincentives) the draining, filling, or other alteration of wetlands for agricultural use. The law allows exemptions from pen- alties in some cases, especially if the farmer agrees to restore the altered wetland or other wetlands that have been converted to agri- cultural use. The Wetlands Reserve Program of the 1990 Food, Agriculture, Conservation, and Trade Act authorizes the Federal Government to purchase conservation easements from landowners who agree to protect or restore wetlands. The Consolidated Farm Service Agency (formerly the Agricultural Stabilization and Con- servation Service) administers the Swampbuster provisions and Wet- lands Reserve Program. The Natural Resources Conservation Service (formerly the Soil Conservation Service) determines com- pliance with Swampbuster provisions and assists farmers in the iden- tification of wetlands and in the development of wetland protection, restoration, or creation plans. The 1986 Emergency Wetlands Resources Act and the 1972 Coastal Zone Management Act and amendments encourage wetland protection through funding incentives. The Emergency Wetland Resources Act requires States to address wetland protection in their Statewide Comprehensive Outdoor Recreation Plans to qualify for Federal funding for State recreational land; the National Park Ser- vice provides guidance to States in developing the wetland compo- nent of their plans. Coastal States that adopt coastal-zone manage- ment programs and plans approved by the National Oceanic and Atmospheric Administration are eligible for Federal funding and technical assistance through the Coastal Zone Management Act. State wetland activities. The Georgia Department of Natu- ral Resources is the principal State agency reviewing development activities in wetlands. Georgia has a coastal regulatory program and requires a State permit for development activities in coastal marshes. A similar program for regulating activities in freshwater wetlands does not exist. The Georgia Water Quality Control Act and section 401 of the Federal Clean Water Act provide indirect protection of freshwater wetlands in some instances. Under these two acts, the Environmental Protection Division of the Department of Natural Resources must certify, for both freshwater and estuarine areas, that wetland activities will not degrade water quality (Wagner and oth- ers, 1989). In 1970, Georgia enacted the Coastal Marshlands Protection Act to protect and conserve estuarine marshlands. Since that time, permits issued by the Department of Natural Resources' Coastal Resources Division have allowed less than 600 acres of jurisdictional marshlands to be filled by nonexempt activities. Total coastal marsh- land losses, however, have been much higher as a result of filling for public works projects, which are exempt. For example, the esti- mated loss of tidal wetlands resulting from the construction of In- terstate 95 through Georgia is approximately 4,000 acres (Georgia Department of Natural Resources, 1992). Nonregulatory programs include acquisition of wetlands as part of wildlife-management areas and public fishing areas by the De- partment of Natural Resources' Game and Fish Division. Total wet- land acreage owned by the State is estimated to exceed 57,000 acres. Wetland acquisitions are a priority of the Preservation 2000 pro- gram of 1991. Recent wetland tracts acquired with Preservation 2000 funds include approximately 7,000 acres of tidal salt marshes on two coastal barrier islands and approximately 6,000 acres of flood-plain swamp on the lower Altamaha River. Small areas of wetlands also have been enhanced, restored, or constructed by the Department of Natural Resources for mitigation, wastewater treat- ment, or waterfowl habitat management (Georgia Department of Natural Resources, 1992). 166 National Water Summary Wetland Resources: STATE SUMMARIES Regional, county, and local wetland activities. "Growth Strategies Legislation" adopted in 1989 requires county and local governments to formulate planning and land-use control pro- grams that include steps to protect wetlands (Georgia Department of Natural Resources, 1992). Guidelines for these county and local protection plans are being developed by the Department of Natural Resources, the Department of Community Affairs, and Regional De- velopment Centers. Private wetland activities. Many private organizations in Georgia such as the Georgia Conservancy, the Sierra Club, and the National Wildlife Federation lobby for wetland-protection measures, participate in litigation involving wetland issues, and comment on State and Federal permits allowing wetland alterations. The Nature Conservancy of Georgia and the Georgia Wildlife Federation are acquiring river flood plains for preservation, primarily along the Altamaha and Alcovy Rivers, respectively. References Cited Carter, R.F., and Hopkins, E.H., 1986, Georgia surface-water resources, in U.S. Geological Survey, National water summary 1985 Hydrologic events and surface-water resources: U.S. Geological Survey Water- Supply Paper 2300, p. 195-200. Clark, W.Z.. Jr., and Zisa, A.C., 1976, Physiographic map of Georgia: At- lanta, Ga., Department of Natural Resources, scale 1:2,000,000. Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Dahl, T.E., 1990, Wetlands Losses in the United States. 1780's to 1980's: Washington, D.C.. U.S. Fish and Wildlife Service Report to Congress, 13 p. Dahl, T.E., Johnson, C.E., and Frazer, WE., 1991, Wetlands Status and trends in the conterminous United States, mid-1970's to mid-1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 22 p. Federal Geographic Data Committee, 1992, Application of satellite data for mapping and monitoring wetlands: U.S. Geological Survey Federal Geographic Data Committee Technical Report 1, 44 p. Field, D.W., Reyer, A.J., Genovese, P.V., and Shearer, B.D., 1991, Coastal wetlands of the United States: Washington, D.C., National Oceanic and Atmospheric Administration and U.S. Fish and Wildlife Service co- operative report, 59 p. Georgia Department of Natural Resources, 1992, Water quality in Georgia, 1990-1991: Atlanta, Georgia Department of Natural Resources, 69 p. Hefner, J.M., and Brown, J.D., 1985, Wetland trends in the southeastern United States: Wetlands, v. 4, p. 1-12. Hefner, J.M., Wilen, B.O., Dahl, T.E., and Prayer, W.E., 1994, Southeast wetlands Status and trends, mid-1970's to mid-1980's: Atlanta, Ga., U.S. Fish and Wildlife Service, 32 p. Izlar, R.L., 1984a, Some comments on fire and climate in the Okefenokee swamp-marsh complex, in Cohen, A.D., Casagrande, D.J., Andrejko, M.J., and Best, G.R., eds., The Okefenokee Swamp Its natural his- tory, geology, and geochemistry: Los Alamos, N. Mex., Wetland Sur- veys, p. 70-85. ____1984b, A history of Okefenokee logging operations A bourbon and branch water success story, in Cohen, A.D., Casagrande, D.J., Andrejko, M.J., and Best, G.R., eds., The Okefenokee Swamp Its natural history, geology, and geochemistry: Los Alamos, N. Mex., Wetland Surveys, p. 5-17. Kalla, P.I., Fasselt, Veronica, Rigdon, T.A., and Bowling, S.M., 1993, Ad- vance identification of wetlands in Georgia, in Hatcher, K.J., ed., Pro- ceedings of the 1993 Georgia Water Resources Conference, Athens, Ga., April 20-21, 1993: Athens, The University of Georgia, Institute of Natural Resources, p. 345-348. Laerm, Joshua, and Freeman, B.J., 1986, Fishes of the Okefenokee Swamp: Athens, The University of Georgia Press, 118 p. Laerm, Joshua, Freeman, B.J., Vitt, L.J., and Logan, L.E., 1984, Checklist of vertebrates of the Okefenokee Swamp, in Cohen, A.D., Casagrande, D.J., Andrejko, M.J., and Best, G.R., eds., The Okefenokee Swamp Its natural history, geology, and geochemistry: Los Alamos, N. Mex., Wetland Surveys, p. 682-691. Rykiel, E.J., Jr., 1984, General hydrology and mineral budgets for Okefe- nokee Swamp Ecological significance, in Cohen, A.D., Casagrande, D.J., Andrejko, M.J., and Best, G.R., eds.. The Okefenokee Swamp Its natural history, geology, and geochemistry: Los Alamos, N. Mex., Wetland Surveys, p. 212-228. Sanders, Sigrid, 1987, Studying the many faces of the Okefenokee Swamp: Athens, The University of Georgia, Research Reporter, v. 15, no. 4, p. 7-11. Teal, John, and Teal, Mildred, 1969, Life and death of the salt marsh: New "York, National Audubon Society and Ballantine Books, Inc., 274 p. Tiner, R.W, Jr., 1984, Wetlands of the United States Current status and recent trends: Washington, D.C., U.S. Fish and Wildlife Service, 59 p. U.S. Fish and Wildlife Service, 1992, Regional wetlands concept plan Emergency Wetlands Resources Act, southeast region: Atlanta, Ga., U.S. Fish and Wildlife Service, 259 p. Vince, S.W., Humphrey, S.R., and Simons, R.W, 1989, The ecology of hydric hammocks A community profile: U.S. Fish and Wildlife Service Biological Report 85(7.26), 81 p. Wagner, Wendy, Carr, David, and Kellett, Katie, 1989, A citizen's guide to protecting wetlands in Georgia: Charlottesville, Va., Southern Envi- ronmental Law Center, 90 p. Wharton, C.H., 1977, The natural environments of Georgia: Georgia De- partment of Natural Resources Bulletin 114, 227 p. ____1978. Physiography and biota of Georgia: BioScience, v. 28, no. 5, p. 336-339. Wiegert, R.G., and Freeman, B.J., 1990, Tidal salt marshes of the south- east Atlantic coast A community profile: U.S. Fish and Wildlife Service Biological Report 85(7.29), 70 p. Yin, Zhi-\ong, and Brook, G.A., 1992, The impact of the Suwannee River sill on the surface hydrology of Okefenokee Swamp, U.S.A.: Journal of Hydrology, v. 136, no. 1-4, p. 193-217. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Survey, Peachtree Business Center, Suite 130, 3089 Amwiler Road, Atlanta, GA 30360; Regional Wetland Coordinator, U.S. Fish and Wildlife Service, 1875 Century Building, Suite 200, Atlanta, GA 30345 Prepared by Melanie R. Darst and Helen M. Light, U.S. Geological Survey U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources 167 Hawaii Wetland Resources We'etlands constitute less than 3 percent of the State of Hawaii but have had a major economic effect on the development of Hawaiian society both before and after European contact. Native Hawaiian communities depended on wetlands for cultivation of taro and other staple food crops and for coastal fisheries. After the arrival of Eu- ropean and Asian immigrants, wetlands were used for rice and wa- tercress cultivation. These agricultural uses of wetlands continue to the present, although their economic importance has declined be- cause of demographic shifts and increased importation of food. Wetlands provide important waterfowl and shorebird habitat. Endemic and endangered species that rely on Hawaiian wetlands include the Hawaiian stilt, Hawaiian coot, Hawaiian gallinule, and Hawaiian duck (Hawaii Department of Land and Natural Resources, 1988). Wetlands also are used by migratory shorebirds such as the Pacific golden plover and waterfowl such as the pintail duck (Ha- waii Department of Land and Natural Resources, 1988). Some en- demic Hawaiian plants are found only in wetlands (Vogl and Henrickson, 1971; Elliot, 1981). In recent years, recreational, educational, and scientific uses of wetlands have increased. The Waimanu Valley on the island of Hawaii (figs. 1 and 2A) is managed as a part of the National Estua- rine Research Reserve system for such purposes. Wetlands can improve water quality (Hemond and Benoit, 1988) and reduce flooding (Carter, 1986). Wetlands in Pearl Har- bor are being considered for use as sediment traps by the U.S. Navy (Stephanie Aschmann, U.S. Navy, oral commun., 1992). The Kawainui Marsh is an example of a wetland managed for flood pro- tection. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deepwater habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and others, 1979). The distribution of wetlands and deepwater habitats in Hawaii is shown in figure 2A; only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Hawaii are described below. System Palustrine, Lacustrine Riverine. Figure 1, Estuarine wetland in Waimanu Valley on the island of Hawaii. (Photograph by B.R. Hill, U.S. Geo- logical Survey.) Wetland description Nontidal and tidal-freshwater wetlands in which vegetation is predominantly trees {forested wet- lands); shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted herba- ceous plants (persistent- and nonpersistent- emergent wetlands); or submersed and (or) floating plants (aquatic beds). Also, intermit- tently to permanently flooded open-water bod- ies of less than 20 acres in which water is less than 6.6 feet deep. Nontidal and tidal-freshwater wetlands within an intermittently to permanently flooded lake or reservoir larger than 20 acres and (or) deeper than 6.6 feet. Vegetation, when present, is pre- dominantly nonpersistent emergent plants (non- persistent-emergent wetlands}, or submersed and (or) floating plants (aquatic beds), or both. Nontidal and tidal-freshwater wetlands within a channel. Vegetation, when present, is same as in the Lacustrine System. Tidal wetlands in low-wave-energy environments where the salinity of the water isgreaterthan 0.5 part per thousand (ppt) and is variable owing to evaporation and the mixing of seawater and freshwater. Tidal wetlands that are exposed to waves and cur- rents of the open ocean and to water having a salinity greater than 30 ppt. On the basis of mapping by the FWS National Wetland Inven- tory, wetland area in Hawaii has been estimated to be 110,810 acres (Hawaii Department of Land and Natural Resources, 1988). The estimate includes areas of mixed wetlands and upland rain forest (Dennis Peters, U.S. Fish and Wildlife Service, written commun., 1993). Almost 90 percent of the wetland area is palustrine wetlands (Hawaii Department of Land and Natural Resources, 1988). The FWS survey did not include marine wetlands, which are small and are not considered in this report. About 70 percent of Hawaiian wet- lands are 5 acres or less, 20 percent are between 5 and 25 acres, and the remaining 10 percent are larger than 25 acres (Hawaii De- partment of Land and Natural Resources, 1988). Estuarine. Marine 168 National Water Summary Wetland Resources: STATE SUMMARIES Palustrine wetlands. The largest wetlands in the State are palustrine wetlands on the windward (northeastern) mountain slopes on the islands of Kauai, Maui, and Hawaii. These are primarily emergent and scrub-shrub wetlands and are known locally as bogs. Palustrine emergent wetlands also are present upstream from some coastal, estuarine wetlands. Lacustrine wetlands. Only a few lacustrine wetlands exist in the Hawaiian Islands. Lake Waiau is a small natural lake near the summit of Mauna Kea on the island of Hawaii. A number of small lakes occupy topographic depressions on Niihau. Several reservoirs are located on Kauai, Oahu, Molokai, and Maui. W '0 B PRECIPITATION -10 - Line of equal annual precipitation- Interval, in inches, is variable. Kauai M/Wlf- Wainteale 150 WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown ^^^1 Predominantly wetland , Predominantly deepwater habitat Kahoolawe Vallev Nation^ Esiuanre Research Preserve 0 10 20 30 MILES h^ i 0 10 20 30 KILOMETERS Figure 2. Wetland distribution and average annual precipitation in Hawaii. A, Distribution of wetlands and deepwater habitats. B. Average annual precipitation. (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 7997. B, Lee and \felenciano, 1986.) National Water Summary Wetland Resources: HAWAII 169 Riverine wetlands. Riverine wetlands in the State are in all four subsystems of the FWS classification: Tidal, Lower Perennial, Upper Perennial, and Intermittent. A total of 376 perennial streams and more than 100 intermittent streams were identified in Hawaii in a recent survey by the Hawaii Cooperative Park Service Unit (1990). Estuarine wetlands. Estuarine emergent wetlands are present at the mouths of many rivers, usually along the wet, windward shores of the major islands. Forested estuarine wetlands also have formed because of the introduction of mangrove in some coastal areas on Oahu and Molokai. Anchialine pools are a unique type of estuarine wetland. These pools form in collapsed lava tubes and have a subsurface connec- tion to the ocean. Therefore, the pools are affected by tidal action, although they are rarely, if ever, inundated by seawater. These wet- lands pools average about 1 acre in area (Hawaii Department of Land and Natural Resources, 1988) and support populations of endemic shrimp. Anchialine pools were not included in the FWS National Wetlands Inventory maps; the Hawaii Department of Land and Natural Resources (1988) estimated that the pools have a total area of about 700 acres. Fishponds constructed by native Hawaiians along the shores of the islands are another type of estuarine wetland. The ponds are formed by walls built of stone. Although artificial, these ponds are economically and culturally important and support several plant and animal species (Hawaii Department of Land and Natural Resources, 1988). Heeia fishpond on Oahu is an example of one such pond that is now preserved because of its cultural importance. HYDROLOGIC SETTING Hydrologic conditions on the Hawaiian islands are largely de- termined by climate and topography. When moisture-laden air masses moving with the trade winds reach the volcanic mountains that form the islands, the air masses are forced up the slopes, where they cool in the higher altitudes and release their moisture. Because of this climatic phenomenon, known as the orographic effect, rain- fall is more plentiful on the windward sides of the islands (fig. 2B) (Blumenstock and Price, 1961). On the highest mountains (Haleakala on Maui, maximum altitude of 10,021 feet; Mauna Kea and Mauna Loa on Hawaii, maximum altitudes of 13,796 and 13,078 feet, respectively), the trade winds move around the peaks, and the maximum rainfall is at altitudes of 2,000 to4.000 feet; on the lower mountain ranges, the trade winds move over the mountains, and the rainfall maximums are at or near the crests (Blumenstock and Price, 1961). Rainfall gradients on the larger islands are high; average annual totals can range from greater than 200 inches to as little as 10 inches within 10 miles (fig. 2B). Geographically, evaporation is inversely proportional to rainfall and is less variable; the maximum annual pan-evaporation rate is about 106 inches, and the minimum is about 17 inches (Hawaii Department of Land and Natural Re- sources, 1973). Runoff averages about 40 percent of rainfall (Takasaki, 1978). Ground water on each island occurs primarily as a basal lens of freshwater floating on denser saltwater (fig. 3) (Valenciano, 1985). These floating freshwater lenses arc known in Hawaii as basal ground water. The upper extent of a lens, the basal water table, is generally less than 100 feet above sea level (Takasaki, 1978; Valenciano, 1985). Despite large amounts of rainfall in some areas, wetlands are not extensive in the Hawaiian islands because of the generally steep topography and the high permeability of bedrock (Elliot, 1981). Most water falling as rain travels rapidly to the ocean as surface- water and ground-water flow (Takasaki. 1978). Wetlands form only where local hydrologic conditions favor retention of water near the land surface (fig. 3). Water is more likely to accumulate where precipitation is high and evaporation is low. In Hawaii, extensive bogs are confined to areas where rainfall exceeds 150 inches annually (fig. 2A and 2B). These areas are at altitudes between 1,500 and 5,000 feet on wind- ward slopes. On the basis of limited pan-evaporation data, evapo- ration in these areas ranges from 50 to 95 inches annually (Hawaii Department of Land and Natural Resources, 1973). Wetlands commonly form only where the water table intersects the land surface. Topography and water-table configuration deter- mine the extent of areas where the land surface and water table in- tersect. Most of the land surface of the islands is many hundreds of feet above the basal water table. Therefore, basal ground water sup- ports only a narrow zone of estuarine and palustrine wetlands near the shore, where the water table and the land surface intersect (fig. 3). Many of Hawaii's estuarine wetlands have developed over geo- logic time as a result of gradual subsidence of the islands and the resulting rise in sea level relative to the land surface (Macdonald and others, 1970). The relative rise in sea level reduced the gradi- EXPLANATION Basal water table Dike-impounded water table lllf/Mf/ Emergent vegetation ^f Ash bed ^H Alluvium Figure 3. Generalized cross section of a Hawaiian island showing hydrologic and geologic features that affect wetland distribution. (Source: Modified from Takasaki, 1978.) 170 National Water Summary Wetland Resources: STATE SUMMARIES ent of streams entering the ocean. Sediments carried by the streams the summit of Mount Waialeale. The extensive bogs on Kauai, Maui, were deposited near the stream mouths, and the accumulated de- and Hawaii occupy gently sloping mountainsides where rainfall is posits were colonized by wetland vegetation. Wetlands in Pearl retained at the land surface (Fosberg, 1961, p. 21; van't Woudt and Harbor on Oahu and in Waimanu and Waipio Valleys on the island Nelson, 1963 p. 23; Vogl and Henrickson, 1971, p. 479). of Hawaii are examples of this process. Geologic heterogeneities, including andesitic lava flows, vol- Topography affects the retention of surface runoff during rain- canic dikes, ash beds, soils, and alluvium, can restrict infiltration storms. On the steep, highly eroded slopes of Oahu, runoff is rapid; of rainfall, resulting in surface saturation. The extensive bogs on water does not accumulate at the land surface, and wetlands are rare the islands of Kauai, Maui, and Hawaii have formed on soils, ash (fig. 2A). On the younger islands of Maui and Hawaii, stream ero- layers, or andesitic lava less permeable than the underlying basaltic sion has not progressed to the same extent as on Oahu, and much of lava (Stearns and Macdonald, 1942, 1946; Macdonald and others, the gently sloping surface of the original volcanic domes is still 1960). intact. On Kauai, caldera filling has resulted in nearly flat areas near Low-permeability clay layers underlie many bogs in Hawaii. These clays result from weathering of bedrock in high-rainfall ar- eas that have abundant plant remains on the forest floor. The organic Table 1. Selected wetland-related activities of government adds deriyed from d ing plants cause rapid chemical weather- agenc.es and pr.vate orgamzat.ons m Hawa,,, 1993 ing rf ^^ Although ^ characteristic clay layers have been [Source: Classification of activities is generalized from information provided considered a factor in bog development (Skottsberg, 1940; Fosberg, by agencies and organizations. , agency or organization participates in iri^, VVI T ,. , XT , in/n \r i A u i imi\ wetland-related activity; ... agency? organization does not participate in 1961 5 vant Woudt and Nelson' 1963 > Vo&1 and Henrickson, 1971), wetland-related activity. MAN, management; REG, regulation; R&C, restora- the clay might actually be a result rather than a cause ot impeded tion and creation; LAN, land acquisition; R&D, research and data collection; drainage (Wentworth and others, 1940). D&l, delineation and inventory] Not mucn js known concerning the hydrologic functions of Hawaiian wetlands. Coastal wetlands are generally in ground-water ^ <$> <& -^ <& <£ discharge zones, and upland bogs are generally in ground-water Agency or organization_____________^ ^ ^ ^ ^ S> recharge zones, but the importance of wetlands in controlling rates FEDERAL of ground-water movement is not known. A study of the Alakai Department of Agriculture Swamp on Kauai indicated that recharge from the swamp to the basal Consolidated Farm Service Agency............................. aquifer was not significant (van't Woudt and Nelson, 1963). Storage Forest Service.................................................................. of surface runoff in bog peat (partially decomposed plant material) Natural Resources Conservation Service.................. . . . { h j streamflow following rains (Skottsberg, 1940; van't Department of Commerce & FF ; , *<^f^ m , , ^ « ^ /^ / National Oceanic and Woudt and Nelson, 1963). The bog in the Ka au Crater on Oahu was Atmospheric Administration.......................................... formerly used as a water-supply reservoir (Elliot, 1981). When bog Department of Defense peat is completely saturated, bogs can act as sources of overland Army Corps of Engineers............................................... . flow during rainstorms and might increase runoff (van't Woudt and Marine Corps ................................................................... . Nelson, 1963). Coastal wetlands can reduce flooding because of Navy................................................................................... ... ., -r Department of the Interior their capacity to store surface runoff. Fish and Wildlife Service ............................................... Geological Survey........................................................... National Biological Survey............................................ .. National Park Service .................................................... .... The Rawaii Department of Land and Natural Resources (1988) Environmental Protection Agency................................... . . ji^iij TI i. ^ c STATE estimated that total wetland acreage in Hawaii before European Department of Health contact in 1778 was 110,000 acres. Wetland area was about 114,000 Office of Environmental Quality Control...................... acres in 1900 because of increased wetland agriculture as rice pro- Department of Land and Natural Resources duction became important. Since then, wetland agricultural acre- Commission on Water Resource Management......... . has declined by about 10,000 acres to a remnant of 420 acres Division of Forestry and Wildlife................................... ...... j r ^ j* j..- Division of Water and Land Development................... . .. . used for taro and watercress production. Division of Land Management...................................... . According to a recent FWS report (Dahl, 1990), Hawaii has lost Office of Conservation and about 7,000 acres of wetlands since the 1780's. These losses were Environmental Affairs ..................................................... in coastal estuarine and palustrine wetlands at altitudes less than Office of State Planning ^OQO feet (Andy Yuen, U.S. Fish and Wildlife Service, written Coastal Zone Management Program........................... . commun., 1992). Estimates of predevelopment wetland area (58,800 University of Hawaii ' ' * 0 ^ j i T^ ui/inr, Environmental Center . acres) and recent wetland area (51,800 acres) used by Dahl (1990) Water Resources Research Center............................. to compute losses are lower than those reported by the Department COUNTY of Land and Natural Resources (1988) because Dahl's (1990) esti- City and County of Honolulu mates do not include some areas of mixed wetland and rain forest """"" "" --- * at altitudes greater than 1,000 feet that were included in the anning Department Department's estimates (Andy Yuen, U.S. Fish and Wildlife Service, County of Kauai written commun., 1992). On the basis of the Department's estimates Planning Department...................................................... . of 110,000 original wetland acres and Dahl's (1990) estimate of County of Maui 7,000 acres lost, Hawaii has lost about 6 percent of its original Planning Department...................................................... . wetlands PRIVATE ORGANIZATIONS wcu<uiu». , , **r^uv. Ducks Unlimited Coastal wetland losses have been greatest on Oahu, where most Hawaii Audubon Society'!ZZZ!Z"Z Z""IZ! of the population of the State resides. Maps and aerial photographs National Audubon Society................................................. . of the Honolulu area before 1940 show many agricultural and coastal Native Hawaiian Plant Society......................................... wetlands that no longer exist. Much of the resort area of Waikiki Outdoor Circle...................................................................... .... was wetian(j before the dredging of the Ala Wai Canal. Many other The Nature Conservancy................................................... . ...... wetlands have been partly or completely filled for industrial and National Water Summary Wetland Resources: HAWAII 171 residential developments. The FWS has estimated that 58 percent of wetlands in the Kaneohe Bay area were lost between 1927 and 1978 (Andy Yuen, U.S. Fish and Wildlife Service, written commun., 1992). The most extensive wetlands in the State are in remote moun- tainous areas removed from agricultural and urban areas (fig. 2A). These wetlands are not presently threatened by human activities but are being degraded by trampling and rooting by feral animals, par- ticularly pigs, and by the introduction of exotic plants (Elliot, 1981). CONSERVATION Many government agencies and private organizations partici- pate in wetland conservation in Hawaii. The most active agencies and organizations and some of their activities are listed in table 1. Federal wetland activities. Development activities in Hawaii wetlands are regulated by several Federal statutory prohibitions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Harbors Act; the 1972 Clean Water Act and amendments; the 1985 Food Security Act; the 1990 Food, Agriculture, Conservation, and Trade Act; the 1986 Emergency Wetlands Resources Act; and the 1972 Coastal Zone Management Act. Section 10 of the Rivers and Harbors Act gives the U.S. Army Corps of Engineers (Corps) authority to regulate certain activities in navigable waters. Regulated activities include diking, deepening, filling, excavating, and placing of structures. The related section 404 of the Clean Water Act is the most often-used Federal legislation protecting wetlands. Under section 404 provisions, the Corps issues permits regulating the discharge of dredged or fill material into wetlands. Permits are subject to review and possible veto by the U.S. Environmental Protection Agency, and the FWS has review and ad- visory roles. Section 401 of the Clean Water Act grants to States and eligible Indian Tribes the authority to approve, apply conditions to, or deny section 404 permit applications on the basis of a pro- posed activity's probable effects on the water quality of a wetland. Most farming, ranching, and silviculture activities are not sub- ject to section 404 regulation. However, the "Swampbuster" provi- sion of the 1985 Food Security Act and amendments in the 1990 Food, Agriculture, Conservation, and Trade Act discourage (through financial disincentives) the draining, filling, or other alteration of wetlands for agricultural use. The law allows exemptions from pen- alties in some cases, especially if the farmer agrees to restore the altered wetland or other wetlands that have been converted to agri- cultural use. The Wetlands Reserve Program of the 1990 Food, Agriculture, Conservation, and Trade Act authorizes the Federal Government to purchase conservation easements from landowners who agree to protect or restore wetlands. The Consolidated Farm Service Agency (formerly the Agricultural Stabilization and Con- servation Service) administers the Swampbuster provisions and Wet- lands Reserve Program. The Natural Resources Conservation Service (formerly the Soil Conservation Service) determines com- pliance with Swampbuster provisions and assists farmers in the iden- tification of wetlands and in the development of wetland protection, restoration, or creation plans. The 1986 Emergency Wetlands Resources Act and the 1972 Coastal Zone Management Act and amendments encourage wetland protection through funding incentives. The Emergency Wetland Resources Act requires States to address wetland protection in their Statewide Comprehensive Outdoor Recreation Plans to qualify for Federal funding for State recreational land; the National Park Ser- vice (NFS) provides guidance to States in developing the wetland component of their plans. Coastal States that adopt coastal-zone management programs and plans approved by the National Oceanic and Atmospheric Administration are eligible for Federal funding and technical assistance through the Coastal Zone Management Act. Several Federal agencies manage wetlands as wildlife refuges and other conservation areas. The FWS manages about 1,400 acres of refuge lands in Hawaii. The U.S. Navy and Marine Corps also manage wetland refuges. Other wetlands are managed by the NFS. State wetland activities. Hawaii has no laws specifically re- lating to wetland protection, but chapter 205A of the Hawaii Re- vised Statutes provides for regulation of coastal areas, including wetlands, in conjunction with the Federal Coastal Zone Manage- ment Act and Clean Water Act. Under the provisions of these and other laws, several State and county agencies regulate the use of wetlands in Hawaii (table 1). The Office of State Planning's Coastal Zone Management Program provides wetlands policy guidance. Policy is enforced through regulation by the county planning de- partments, which have permitting authority for designated Special Management Areas. These areas generally are within 300 feet of the shoreline but can extend much farther inland. The Office of Con- servation and Environmental Affairs of the Department of Land and Natural Resources has permitting authority for all designated con- servation lands, which can include upland as well as coastal wet- lands. The Department of Health and the Coastal Zone Manage- ment Program make determinations of consistency with Federal laws for permits issued by the Corps. The Commission on Water Resource Management, a part of the Department of Land and Natu- ral Resources, has authority to regulate channel alterations and enforce instream-flow standards. The Office of Hawaiian Affairs acts as an advocate for native Hawaiian concerns relating to wet- lands. An effort to review State wetland policies is under way; this effort is being coordinated by the Office of Environmental Quality Control in the Department of Health. The Division of Forestry and Wildlife of the Department of Land and Natural Resources is the principal State wetland-manage- ment agency. The Division manages wildlife refuges and other wetlands. The wetlands in Waimanu Valley on the island of Hawaii are included in the Waimanu National Estuarine Research Reserve, which is administered by the Department of Land and Natural Re- sources in cooperation with the National Oceanic and Atmospheric Administration. Hydrologic data are collected in this reserve by the U.S. Geological Survey in cooperation with the Department. Private wetland activities. Several private organizations en- gage in wetland activities (table 1) in Hawaii. The Nature Conser- vancy manages wetlands within its preserve system. Other groups, including the National and Hawaii Audubon Societies and Ducks Unlimited, are involved in efforts to acquire wetlands for conser- vation purposes. In addition, many other organizations take advo- cacy roles before government agencies in matters concerning wet- lands. These include the Native Hawaiian Legal Corporation, the Sierra Club Legal Defense Fund, the Kawainui Heritage Founda- tion, and the National and Hawaii Audubon Societies. References Cited Blumenstock, D.I., and Price, Saul, 1961, Climates of the States Hawaii: U.S. Department of Commerce, Environmental Science Services Administration, climatography of the States 60-51, 27 p. Carter, Virginia, 1986, An overview of the hydrologic concerns related to wetlands in the United States: Canadian Journal of Botany, v. 64, p. 364-374. Cowardin, L.M.. Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habhats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Dahl, T.E., 1990, Wetlands Losses in the United States, 1780's to 1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 13 p. Elliot, M.E., 1981, Wetlands and wetland vegetation of the Hawaiian Islands: Honolulu, University of Hawaii, M.A. thesis, 228 p. Fosberg, F.R., 1961, Guide to excursion III: Honolulu, Tenth Pacific Sci- ence Congress and University of Hawaii, 207 p. 172 National Water Summary Wetland Resources: STATE SUMMARIES Hawaii Cooperative Park Service Unit, National Park Service, 1990, A pre- liminary appraisal of Hawaii's stream resources: National Park Ser- vice Report R84, 294 p. Hawaii Department of Land and Natural Resources, 1973, Pan evaporation in Hawaii 1894-1970: Hawaii Department of Land and Natural Re- sources Report R51, 82 p. ____1988, State recreation functional plan technical reference document and State comprehensive outdoor recreation plan, wetlands resources plan addendum: Honolulu, Hawaii, Department of Land and Natural Resources, variously paged. Hemond, H.F., and Benoit, Janina, 1988, Cumulative impacts on water quality functions of wetlands: Environmental Management, v. 12, no. 5, p. 636-653. Lee, Reuben, and Valenciano, Santos, 1986, Hawaii surface-water resources, in U.S. Geological Survey, National water summary 1985 Hydro- logic events and surface-water resources: U.S. Geological Survey Water-Supply Paper 2300, p. 201-206. Macdonald, G.A., Abbott, A.T., and Peterson, F.L., 1970, Volcanoes in the sea The geology of Hawaii: Honolulu, University of Hawaii Press, 517 p. Macdonald, G.A., Davis, D.A.. and Cox, D.C., 1960, Geology and ground- water resources of the island of Kauai, Hawaii: Hawaii Division of Hydrography Bulletin 13, 212 p. Skottsberg, Carl, 1940, Report on Hawaiian bogs Proceedings of the Sixth Pacific Science Congress, July 24-August 12, 1939, Berkeley, Stanford, and San Francisco: Berkeley, University of California Press, v. 4, p. 659-661. Stearns, H.T., and Macdonald. G.A., 1942, Geology and ground-water re- sources of the island of Maui, Hawaii: Territory of Hawaii Division of Hydrography Bulletin 7, 344 p. ____1946, Geology and ground-water resources of the island of Hawaii: Territory of Hawaii Division of Hydrography Bulletin 9, 363 p. Takasaki, K.J., 1978, Summary appraisals of the nation's ground-water re- sources Hawaii region: U.S. Geological Survey Professional Paper 813-M, 29 p. Valenciano, Santos, 1985, Hawaii ground-water resources, in U.S. Geologi- cal Survey, National water summary 1984 Hydrologic events, se- lected water-quality trends, and ground-water resources: U.S. Geo- logical Survey Water-Supply Paper 2275, p. 185-191. van't Woudt, B.D., and Nelson, R.E., 1963, Hydrology of the Alakai Swamp, Kauai, Hawaii: Hawaii Agricultural Experiment Station Bulletin 132, 30 p. Vogl, R.J., and Henrickson, James, 1971, Vegetation of an alpine bog on East Maui, Hawaii: Pacific Science, v. 25, p. 475-483. Wentworth, C.K., Wells, R.C., and Alien, V.T., 1940, Ceramic clay in Ha- waii: The American Mineralogist, v. 25, no. 1, p. 2-33. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Sur- vey, 677 Ala Moana Boulevard, Suite 415, Honolulu, HI 96813; Regional Wetland Coordinator, U.S. Fish and Wildlife Service, 911 NE 11th Avenue, Portland, OR 97232 Prepared by B.R. Hill, U.S. Geological Survey U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources 173 Idaho Wetland Resources A,,Ithough Idaho's wetlands account for less than 1 percent of the State's area, its many small and isolated wetlands are essential to the functioning of diverse ecosystems in deserts, plains, and moun- tains (fig. 1). Wetlands provide vital habitat for waterfowl, migra- tory birds, fish, and other wildlife. More than 75 percent of Idaho's wildlife depend on wetlands during some parl of their life cycle (Idaho Department of Fish and Game, 1990). Wetlands enhance the water quality of lakes and streams by removing nutrients and pol- lutants from influent water. During floods, wetlands store floodwater temporarily, slow water velocities, and reduce bank erosion. Cities, small communities, and farms commonly were settled next to or near riparian (streamside) wetlands because of the avail- ability of water and shade. Wetland vegetation generally is more lush and productive than that in uplands; livestock benefit from shade and forage provided by healthy wetlands. Idaho's development was enhanced by extracting large quantities of gold and other metals from streambeds and riparian zones along streams. Idaho's wetlands benefit an increasing population and a large tourism industry by providing unique scenery and recreational opportunities. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deep- water habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and oth- ers, 1979), The distribution of wetlands and deepwater habitats in Idaho is shown in figure 2A; only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Idaho are described below. System Palustrine. Lacustrine Riverine. Figure 1. The Tules, a wetland in an abandoned meander channel of the Owyhee River. Tules is a name commonly used for stands of bulrush or cattail. (Photograph by R.K. Moseley, Idaho Department of Fish and Came.) Wetland description Wetlands in which vegetation is predominantly trees (forested wetlands); shrubs {scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted, herbaceous plants (persistent- and nonpersistent-emergent wetlands); or sub- mersed and {or} floating plants (aquatic beds). Also, intermittently to permanently flooded open-water bodies of less than 20 acres in which water is less than 6.6 feet deep. Wetlands within an intermittently to permanently flooded lake or reservoir. Vegetation, when pres- ent, is predominantly nonpersistent emergent plants (nonpersistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds}, or both. Wetlands within a channel. Vegetation, when pres- ent, is same as in the Lacustrine System. Dahl (1990) estimated that wetlands occupy about 386,000 acres in Idaho. Most of the State's wetlands are in flood plains and riparian areas along streams and other water bodies. These are palustrine wetlands that include swamps (forested wetland); scrub- shrub wetlands that also contain smaller acreages of marsh, wet meadow, and seeps (emergent wetlands); and a few small ponds. Many of the State's wetlands are in National Wildlife Refuges managed by the FWS. The Bear Lake National Wildlife Refuge (NWR) in southeastern Idaho includes about 17,600 acres of wetland-up- land complex consisting of marsh, open water, and grasslands. Other wetlands in southeastern Idaho Oxford Slough in the Bear River Basin and Grays Lake in the Snake River Basin also have exten- sive emergent wetlands; about 13,000 acres of the original lakebed at Grays Lake NWR is being restored to marsh by the FWS. Camas NWR and State refuges at Market and Mud Lakes in eastern Idaho also have marshes. Other refuges in the Snake River Basin are Minidoka NWR, which predominantly consists of scrub-shrub wet- lands along the shores of Lake Walcott on the Snake River; Deer Flat NWR, which includes Lake Lowell Reservoir (about 11,600 acres of wetlands and deepwater habitat); and 109 islands in the Snake River. Notable emergent wetlands are at Camas Prairie Centennial Marsh and C.J. Strike Reservoir. In the northern Rocky Mountains, the Kootenai NWR contains about 2,800 acres of wetlands on the flood plain of the Kootenai River. The mud flats along the Pack River and delta marshes along the Clark Fork are among the larger wet- lands in northern Idaho. Small bogs, which are emergent wetlands that have organic soils and receive moisture only from precipita- tion, also are present in northern Idaho (Bureau of Reclamation, 1992). Wetlands in Idaho's mountains are mostly alpine meadows (emergent wetlands) in flood plains and small shallow lakes and marshes in intermontane basins. In Idaho's plains, most wetlands are associated with river systems, although locally, high water tables sustain small wetlands, and during wet years, playas can be filled by surface-water runoff. Lacustrine wetlands are present in Idaho's lakes and reservoirs; riverine wetlands are present in river channels. HYDROLOCIC SETTING Wetlands are present where there is a persistent water supply at or near the land surface. The location and persistence of the sup- ply are functions of interdependent climatic, physiographic, and 174 National Water Summary Wetland Resources: STATE SUMMARIES PRECIPITATION Line of equal annual precipitation- Interval, in inches, is variable WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown Predominantly wetland Predominantly deepwater habitat 25 50 MILES 0 25 50 KILOMETERS FREE-WATER-SURFACE EVAPORATION 40 Line of equal free-water-surface evaporation Interval 5 inches D ECORECIONS A. Columbia Basin B. Blue Mountains C. Snake River Basin/High Desert D. Northern Basin and Range E. Northern Rockies F. Middle Rockies G. Wyoming Basin H. Wasatch and Uinta Mountains Figure 2. Wetland distribution in Idaho and physical, climatological, and ecological features that control wetland distribution in the State. A, Distribution of wetlands and deepwater habitats. 8, Precipitation. C, Annual free-water-surface evaporation. D, Ecoregions. (Sources: A, T.E. Dahi, U.S. Fish and Wildlife Service, unpub, data, 1991. B, Kjelstrom, 1986. C, Farnsworth and others, 1982. D, Omernik, 1987; landforms data from EROS Data Center.) National Water Summary Wetland Resources: IDAHO 175 hydrologic factors such as precipitation and runoff patterns, evapo- ration potential, topography, and configuration of the water table. Surface water collects in topographic lows, which can be either ground-water recharge or discharge areas. Soil composition deter- mines the rate at which water is recharged or discharged. Precipitation is affected by topography and ranges statewide from less than 10 inches per year on much of the Snake River Plain in southern Idaho to more than 60 inches per year in mountainous areas that are headwaters of the Clearwater River (fig. 25). Greater precipitation in the mountains accounts in large part for the greater wetland acreage in the intermontane basins than on the plains in southern Idaho. Most of the water that supplies wetlands is from spring snowmelt, either as direct runoff or indirectly as recharge to the ground-water system. The timing and volume of runoff affect the establishment and functions of wetlands. Although mountain- ous areas have sufficient precipitation to supply wetlands, steep topography and shifting stream channels can prevent wetland de- velopment. Runoff in the Snake River Basin in southern Idaho is highly regulated by dams; runoff in most other river basins is regu- lated to some degree (Kjelstrom, 1986). Storage has decreased spring floodflows downstream from reservoirs, and wetland veg- etation on the flood plain that normally receives moisture during floods must rely mostly on precipitation and shallow ground water for moisture. Diversions and scant precipitation deplete streamflow; as a result, water quality could be degraded, possibly resulting in changes in wetland functions and wildlife value (Kjelstrom and others, 1991). Evaporation in the State generally increases from north to south (fig. 2C). Superimposed on this pattern are topographic complexi- ties that cause evaporation to decrease with altitude. Evaporation from surface water ranges from 25 to 35 inches during the growing season and from 30 to 45 inches annually (Farnsworth and others, 1982). In Idaho, except for some high mountainous areas, potential evaporation exceeds precipitation during the growing season and wetland development is inhibited. The moisture deficit generally prevents the formation of bogs. The hydrologic setting and functions of wetlands in Idaho dif- fer regionally because of differences in climate, soils, geology, veg- etation, and physiography. Omernik (1987) related these character- istics in order to develop regional patterns that were used to define ecoregions (fig. 2£>). In the Middle and Northern Rockies Ecoregions, mountain ranges are separated by valleys and, in places, broad basins (Pacific Northwest River Basins Commission, 1969; Omernik and Gallant, 1986). The alluvial and outwash deposits in the valleys are porous and permeable and can store and yield large volumes of water. Wetlands appear where less permeable rocks crop out or trap water and establish springs and seeps. The Snake River Basin/High Desert Ecoregion (fig. 2D) is a gently sloping, semiarid plain that contains small wetlands and pla- yas. Most wetlands are along the banks of the Snake River and its tributaries; many are emergent wetlands vegetated by sedges and rushes or are forested and scrub-shrub wetlands dominated by al- der, willow, and cottonwood (Omernik and Gallant, 1986). The Snake River and southern tributaries, such as the Bruneau and Owyhee Rivers, have cut deep canyons into the plain and gen- erally are at a lower altitude than the regional water table; there- fore, the river and its tributaries receive perennial inflow from ground water (Kjelstrom, 1992). Small streams are generally at a higher altitude than the regional water table and flow intermittently in response to surface runoff from precipitation and snowmelt. Shrub and grassland vegetation extends to the banks of intermittent and ephemeral streams. Water held near the surface by low-permeabil- ity rock can maintain small wetlands. Where the Snake River first crosses the Idaho-Oregon border, broad valleys have developed along the Snake, Boise, and Payette Rivers. Wetland acreage has in- creased in the broad river valleys because cropland irrigation re- charges aquifers and ground water maintains summer and fall base flows in streams and drains. In the Columbia Basin and Blue Mountains Ecoregions, wet- lands receive ground water from glacial outwash and alluvial de- posits along streams. However, these types of deposits commonly are higher in altitude than the water table and thus cannot retain sufficient moisture for wetland development. Wetlands also could develop where loess and other windblown deposits are present, but wetland growth is inhibited because the soil is easily eroded. At lower altitudes, wetlands are grazed by livestock; wet meadows on the upper mountain slopes are summer grazing grounds (Pacific Northwest River Basins Commission, 1969). The Northern Basin and Range Ecoregion in southeastern Idaho consists of broad basins between low mountain ranges. Hun- dreds of springs throughout the area provide water for many wet- lands. Large wetland areas along the Bear River and most of its tribu- taries are generally in direct hydraulic connection with ground water (Kjelstrom, 1986). Most of the desert shrubland is grazed or cleared and used for irrigated agriculture, which has decreased wetland vegetation and degraded water quality of nearby wetlands. TRENDS Starting in 1805, explorers, pioneers, and trappers followed the waterways through Idaho. The first effects on wetlands occurred between 1818 and 1827 when beaver were virtually eliminated by trapping (Idaho Department of Fish and Game, 1990). Storage of water behind beaver dams creates wetlands, provides water for veg- etation during dry periods, and decreases downstream bank erosion. Since about 1860, when mining and farming activities began, wet- lands in Idaho have decreased 56 percent from about 877,000 acres to about 386,000 acres (Dahl, 1990). In Idaho, agricultural practices account for most of the human-caused wetland losses; residential and commercial development accounts for most of the remaining losses (Idaho Department of Parks and Recreation, 1987). Of the 19.5 million acres of non-Federal land in Idaho about one- third of the State approximately 33 percent is cropland. Cropland increased by about 400,000 acres from 1967 to 1982. During that time, nearly 10,000 acres of farmland per year were converted to urban uses (Soil Conservation Service, 1984). Many small wetlands within farmlands were filled for urban use. In agricultural areas, conversion to cropland, dewatering for irrigation purposes, contami- nation from nutrients in irrigation-return flow, and overgrazing by livestock contributed to wetland loss or degradation. Livestock graz- ing in wetlands is a complex issue because most of the public land is grazed, and, although much of the riparian area on public lands has been adversely affected, riparian areas are commonly the pri- mary and sometimes the only water supply for livestock that graze on arid rangeland. Results of an inventory of about 250 miles of National Forest riparian areas indicated that no single grazing strat- egy was effective for all areas (Clary and Webster, 1989). In urban areas, wetland losses are attributable to encroachment by residen- tial and commercial construction, channelization for drainage, and dewatering for municipal and industrial purposes. Loss of wetlands also can be attributed to dam and reservoir construction, mining activities, ground-water pumping, river chan- nelization, erosion and sedimentation, and road and railroad con- struction. From 1860 to the 1930's, placer mining along many miles of streambeds damaged adjacent wetlands. Tailings from hard-rock mining and toxic acidic or alkaline drainage have degraded other wetlands. Short-term causes of wetland degradation are wildfires, plant diseases, extremes in weather, and defoliation by cyclic species such as jackrabbits, tent caterpillars, and grasshoppers (Thomas, 1986). Prolonged droughts, such as the one from 1987 to 1992, have tern- 176 National Water Summary Wetland Resources: STATE SUMMARIES porarily reduced the area or functions of some wetlands. Some land-use practices have created new wetlands or enlarged existing ones. Leaking irrigation ditches, uncapped flowing wells, seeps, irrigation tailwater, and irrigation-return flows have increased wetland acreage and improved wetland habitat, notably in southern Idaho. Excavation of gravel pits and construction of reservoirs also have increased wetland acreage. However, such increases are small compared to losses. Ratti and Kadlec (1992) estimated that about 91,000 acres of wetlands are protected in the National Wildlife Refuge system or by the State. Federal laws and State and local planning and regula- tory programs are being used to identify and protect the remaining wetlands. CONSERVATION Many government agencies and private organizations partici- pate in wetland conservation in Idaho. The most active agencies and organizations and some of their activities are listed in table 1. Federal wetland activities. Development activities in Idaho wetlands are regulated by several Federal statutory prohibitions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Harbors Act; the 1972 Clean Water Act and amendments; the 1985 Food Security Act; the 1990 Food, Agriculture, Conservation, and Trade Act; and the 1986 Emergency Wetlands Resources Act. Section 10 of the Rivers and Harbors Act gives the U.S. Army Corps of Engineers (Corps) authority to regulate certain activities in navigable waters. Regulated activities include diking, deepening, Table 1 . Selected wetland-related activities of government agencies and private organizations in Idaho, 1993 [Source: Classification of activities is generalized from information provided by agencies and organizations. , agency or organization participates in wetland-related activity; ., agency or organization does not participate in wetland-related activity. MAN, management; REG, regulation; R&C, resto- ration and creation; LAN, land acquisition; R&D, research and data collec- tion; D&l, delineation and inventory] Agency or organization FEDERAL Department of Agriculture Consolidated Farm Service Agency.............. Forest Service .................................................... Natural Resources Conservation Service ... Department of Defense Army Corps of Engineers ................................. Military reservations........................................ Department of the Interior Bureau of Land Management......................... Bureau of Reclamation .................................... Fish and Wildlife Service ................................. Geological Survey............................................. National Biological Service ............................ National Park Service ...................................... Environmental Protection Agency..................... STATE Department of Agriculture .................................. Department of Fish and Game ............................ Department of Health and Welfare Division of Environmental Quality.................. Department of Parks and Recreation ............... Department of Transportation ............................ Department of Water Resources ....................... SOME COUNTY AND LOCAL GOVERNMENTS PRIVATE ORGANIZATIONS Ducks Unlimited................................................. The Nature Conservancy................................. filling, excavating, and placing of structures. The related section 404 of the Clean Water Act is the most often-used Federal legislation protecting wetlands. Under section 404 provisions, the Corps issues permits regulating the discharge of dredged or fill material into wetlands. Permits are subject to review and possible veto by the U.S. Environmental Protection Agency (EPA), and the FWS has review and advisory roles. Section 401 of the Clean Water Act grants to States and eligible Indian Tribes the authority to approve, apply conditions to, or deny section 404 permit applications on the basis of a pro- posed activity's probable effects on the water quality of a wetland. Most farming, ranching, and silviculture activities are not sub- ject to section 404 regulation. However, the "Swampbuster" provi- sion of the 1985 Food Security Act and amendments in the 1990 Food, Agriculture, Conservation, and Trade Act discourage (through financial disincentives) the draining, filling, or other alteration of wetlands for agricultural use. The law allows exemptions from pen- alties in some cases, especially if the farmer agrees to restore the altered wetland or other wetlands that have been converted to agri- cultural use. The Wetlands Reserve Program of the 1990 Food, Agriculture, Conservation, and Trade Act authorizes the Federal Government to purchase conservation easements from landowners who agree to protect or restore wetlands. The Consolidated Farm Service Agency (formerly the Agricultural Stabilization and Con- servation Service) administers the Swampbuster provisions and Wet- lands Reserve Program. The Natural Resources Conservation Service (formerly the Soil Conservation Service) (NRCS) determines compliance with Swampbuster provisions and assists farmers in the identification of wetlands and in the development of wetland pro- tection, restoration, or creation plans. The 1986 Emergency Wetlands Resources Act encourages wetland protection through funding incentives. The act requires States to address wetland protection in their Statewide Comprehen- sive Outdoor Recreation Plans to qualify for Federal funding for State recreational land; the National Park Service (NFS) provides guidance to States in developing the wetland component of their plans. The U.S. Forest Service manages about 20 million acres of National Forest in Idaho and is assessing a process to evaluate the value and function of each wetland (Bureau of Reclamation, 1992). From 1964 to 1980, forested wetlands were further protected by the designation of about 4 million acres as wilderness areas. The Bureau of Land Management (BLM) manages about 12 million acres, of which about 69,000 acres are riparian wetlands (Bureau of Reclamation, 1992). Waterfowl-habitat management areas have been designated on 68 sites within BLM lands, and habi- tat-improvement projects have been completed on 2,000 acres. In the 1970's, the BLM began protecting riparian areas by fencing stream segments, planting willows and other woody species, build- ing check dams, and introducing beavers (Thomas, 1988). Intensive inventories of conditions, objectives, plans, and restoration will be made on 10,400 acres from 1991 to 1995 (Bureau of Land Manage- ment, 1991). The FWS manages six National Wildlife Refuges and one wa- terfowl-production area. The agency is conducting numerous re- search and education projects involving wetland enhancement and conservation. The NFS manages about 85,000 acres in Idaho. To date (1993), no estimates of wetland acreage on those lands have been made. The Bureau of Reclamation (BOR) is carrying out cooperative research projects that demonstrate how wetlands and riparian habitat can be preserved and enhanced as part of an overall water-resources management plan. Most BOR wetland-restoration and development projects are multipurpose, but all projects enhance, waterfowl habi- tat in accordance with the North American Waterfowl Management Plan of 1986. Research projects near American Falls Reservoir are designed to determine the effectiveness of small wetland-area im- National Water Summary Wetland Resources: IDAHO 177 poundments on wetland plant communities, to improve quality of irrigation-return flow, and to enhance waterfowl habitat by devel- oping a large wetland area on the north side of the reservoir (Bureau of Reclamation, 1992). The NRCS will provide technical assistance to the BOR in the design and operation of a nutrient and sediment-control system adjacent to Cascade Reservoir (P.H. Calverley, Soil Conservation Service, written commun., 1992). Three shallow, vegetated wetland cells and one deepwater pond will be used to improve the water quality of irrigation-return flow. The NRCS Aberdeen Plant Materi- als Center, in cooperation with several Federal and State agencies, will conduct a long-term project to assemble, evaluate, select, and release for commercial production several improved varieties of ri- parian wetland plant species (P.H. Calverley, Soil Conservation Service, written commun., 1992). The National Water Quality Assessment study of the upper Snake River Basin by the U.S. Geological Survey will address the effects of long-term water use on ground- and surface-water qual- ity. Several wetland areas are within the basin. State wetland activities. The Idaho State Water Plan states that, insofar as is possible, the State should assume responsibility for wetland management and protection (Idaho Water Resource Board, 1992). Policy plans made by the Idaho Department of Fish and Game for 1991-2005 focus land-acquisition efforts on wetland areas where habitat protection is critical. Some activities adminis- tered by the department in the last 5 years include (1) the develop- ment or protection of about 500 blocks of wetland habitat and nearly 1,500 waterfowl nesting structures (Habitat Improvement Program); (2) mitigation for about 11,000 acres of wetland area lost to con- struction of several reservoirs (Wildlife Mitigation Program); (3) acquisition of about 4,300 acres of wetland habitat by use of water- fowl-stamp funds (State Duck Stamp Program); (4) identification of more than 200 valuable wetlands for protection (Idaho National Heritage Program); (5) encouragement of local participation and volunteer efforts to address nonpoint sources of pollution (Antidegradation Program); and (6) the publication and dissemina- tion of several leaflets and guides dealing with waterways, riparian areas, wetlands, and aquatic biota (Aquatic Education Program) (Groen, 1991). The Division of Environmental Quality of the Department of Health and Welfare reviews section 404 permit applications to en- sure compliance with State water-quality laws. A permit is not issued by the Corps without certification of compliance by the division. Pursuant to section 305(b) of the Clean Water Act, the division sub- mits to the EPA and the U.S. Congress a biennial assessment of the State's surface-water quality, including that in wetlands. Idaho's Statewide Comprehensive Outdoor Recreation Plan was completed by the Department of Parks and Recreation and adopted by the Governor in January 1988. The Department is responsible for maintaining lists of wetlands and endangered plant species un- der the plan. The Idaho Wetlands Conservation Priority Plan, pre- pared by the Department, calls for the identification of wetlands warranting priority consideration for protection (Howard, 1991). One of the wetlands identified for priority protection is The Tules (fig. 1), which consists of about 160 acres in an abandoned mean- der channel of the Owyhee River. The Department also manages about 580 miles of nationally designated wild and scenic rivers that include riparian wetland. The Idaho Department of Water Resources issues and manages surface- and ground-water rights and administers diverse activities that can affect wetlands. The Idaho Department of Transportation analyzes alternative roadway locations and uses construction tech- niques to lessen the degradation or loss of wetlands. When loss or degradation occurs, mitigation in the form of restoration or other compensation is required. A wetland bank in Idaho (Tiedemann, 1991) may be used when mitigation of unavoidable impacts caused by construction is not possible; compensation may be made by the offsite creation, restoration, or enhancement of wetlands. The Uni- versity of Idaho and the Idaho Water Resources Research Institute are conducting projects to assess the effectiveness of constructed wetlands supplied by irrigation-return flow near Twin Falls and by sewer effluent from an aquaculture facility near Moscow. Also, the institute, in cooperation with the Idaho Bureau of Mines, is con- ducting projects to evaluate wetland design for the reduction of heavy metals in runoff from mine-waste sites. The University of Idaho's Cooperative Extension System is conducting research on pollutant and sediment runoff from several small parcels of land on which different grazing practices are used. County and local wetland activities. Most development in Idaho's wetlands is regulated by Federal and State laws. However, some city and county governments have ordinances and planning and zoning regulations that protect wetland areas and functions. Guidance and assistance to farmers and other landowners for wet- land conservation are provided by the University of Idaho's Coop- erative Extension System. Private wetland activities. The Nature Conservancy and Ducks Unlimited have participated in several projects involving acquisition and restoration of wetlands. Other organizations that participate in wetland-protection activities in the State include The National Wetlands Policy Forum, National Wildlife Federation, Wildlife Council, National Audubon Society, Pheasants Forever, Sierra Club, and Idaho Conservation League. Many other groups have formed to restore and preserve specific wetland areas. For example, the Henrys Lake Foundation was formed by summer homeowners, local ranchers, and business owners to restore the fish- ery in Henrys Lake. Money was raised to exclude livestock from the riparian area along a tributary stream (Chaney and others, 1990). In 1986, a group of ranchers in south-central Idaho formed the Beaver Committee with the aim of restoring riparian wetlands, re- ducing soil erosion, and improving the productivity of land for live- stock grazing. About 100 beavers have been relocated to 25 creeks (High Country News, Paonia, Colo., August 24,1992, p. 1,10-12). In Boise, citizen groups protested the residential development of a riparian area in the Boise foothills. As a result, a land exchange between the city of Boise and the developer will preserve 100 acres of wetlands. References Cited Bureau of Land Management, 1991, Riparian-wetland initiative for the 1990s: Bureau of Land Management Report BLM/WO/GI-91/ 001+4340, 50 p. Bureau of Reclamation, 1992, Idaho river systems management study, wet- lands report: Denver, Bureau of Reclamation, 155 p. Chaney, J.E., Elmore, Wayne, and Platts, W.S., 1990, Livestock grazing on western riparian areas: Eagle, Idaho, Northwest Resource Informa- tion Center, Inc., 45 p. [2d printing.] Clary, W.P., and Webster, B.F., 1989, Managing grazing of riparian areas in the intermountain region: U.S. Forest Service, Intermountain Re- search Station General Technical Report INT-263, 11 p. Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Dahl, T.E., 1990, Wetlands Losses in the United States, 1780's to 1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 13 p. Farnsworth, R.K., Thompson, E.S., and Peck, E.L., 1982, Evaporation at- las for the contiguous 48 United States: National Oceanic and Atmo- spheric Administration Technical Report NWS 33, 27 p. Groen, Cal, 1991, A look at the players Federal and State roles, Idaho Department of Fish and Game role in wetlands protection, in Wetlands protection in Idaho Living with "no net loss": Boise, University of Idaho, Idaho Water Resources Research Institute, [about 140] p. Howard, Jake, 1991, The role of the Idaho Department of Parks and Recre- ation in wetlands protection, in Wetlands protection in Idaho Liv- 178 National Water Summary Wetland Resources: STATE SUMMARIES ing with "no net loss": Boise, University of Idaho, Idaho Water Re- sources Research Institute, [about 140] p. Idaho Department of Fish and Game, 1990, Between land and water The wetlands of Idaho: Idaho Department of Fish and Game, Nongame Wildlife Leaflet no. 9, 12 p. Idaho Department of Parks and Recreation, 1987, Idaho wetlands conser- vation priority plan An addendum to the 1983 statewide compre- hensive outdoor recreation plan: Boise, Idaho Department of Parks and Recreation, 13 p. Idaho Water Resource Board, 1992, Idaho State water plan: Boise, Idaho Department of Water Resources, 56 p. Kjelstrom, L.C., 1986, Idaho surface-water resources, in U.S. Geological Survey, National water summary 1985 Hydrologic and surface-water resources: U.S. Geological Survey Water-Supply Paper 2300, p. 207- 214. ____1992, Streamflow gains and losses in the Snake River and ground- water budgets for the Snake River Plain, Idaho and eastern Oregon: U.S. Geological Survey Open-File Report 90-172, 71 p. Kjelstrom, L.C., and others, 1991, Idaho floods and droughts, in U.S. Geo- logical Survey, National water summary 1988-89 Hydrologic events and floods and droughts: U.S. Geological Survey Water-Supply Pa- per 2375, p. 255-262. Omernik, J.M., 1987, Ecoregions of the conterminous United States Map supplement: Annals of the Association of American Geographers, v. 77, no. 1, scale 1:7,500,000. Omernik, J.M., and Gallant, A.L., 1986, Ecoregions of the Pacific North- west: U.S. Environmental Protection Agency Report EPA/600/3 - 86/ 033, 39 p. Pacific Northwest River Basins Commission, 1969, Columbia-North Pa- cific region comprehensive framework study of water and related lands, appendix II The region: Vancouver, Wash., Pacific Northwest River Basins Commission, 147 p. Ratti, J.T., and Kadlec, J.A., 1992, Concept plan for the preservation of wetland habitat of the intermountain west North American Water- fowl Management Plan: Portland, Oreg., U.S. Fish and Wildlife Ser- vice, 146 p. Soil Conservation Service, 1984, Idaho's soil and water Condition and trends: Boise, Soil Conservation Service, 24 p. Thomas, A.E., 1986, Riparian protection/enhancement in Idaho: Range- lands, v. 8, no. 5, p. 224-227. ____1988, Seen a riparian lately? Good ones are green!: Idaho Wildlife, v. 8, no. 5, p. 6-9. Tiedemann, R.B., 1991, Development and use of a wetland bank as a miti- gation alternative in Idaho, in Wetlands protection in Idaho Living with "no net loss": Boise, University of Idaho, Idaho Water Resources Research Institute, [about 140] p. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Survey, 230 Collins Road, Boise, ID 83702; Regional Wetland Coordina- tor, U.S. Fish and Wildlife Service, 911 NE 11th Avenue, Portland, OR 97232 Prepared by L.C. Kjelstrom, U.S. Geological Survey U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources 179 Illinois Wetland Resources he diverse wetlands of Illinois, which cover about 3.5 percent of the State, have resulted from the interaction of geologic events, human activities, and hydrologic conditions. The State contains several ecologically significant wetlands. Two examples are Beall Woods on the Wabash River in eastern Illinois and the swamps along the Cache River in the southern part of the State. Beall Woods is one of the last near-virgin stands of wet bottom-land forest in the State, and the Cache River swamps (fig. 1) are among the few bald cypress/tupelo gum swamps remaining in southern Illinois. Core samples from some of the larger bald cypress trees indicate ages of more than 1,000 years. The Cache River swamps also are home to a colony of nesting great blue herons (Barickman, 1992). Wetlands have many fish and wildlife, environmental-quality, and socioeconomic values (Tiner, 1984). Illinois wetlands provide feeding, spawning, and nursery grounds for catfish, sunfish, north- ern pike, muskie, and walleye. Common birds, such as ducks, tur- keys, and owls, and threatened or endangered species, such as American bittern, upland sandpiper, Henslow's sparrow, and north- ern harrier, use Illinois wetlands for feeding and nesting sites (Barickman, 1992). Deer, muskrat, rabbits, beaver, and other fur- bearers use wetlands as a source of food and shelter. Numerous reptile and amphibian species also live in the wetlands of Illinois. The environmental quality of aquatic habitats is enhanced by wetlands. Wetlands absorb nutrients and remove heavy metals and other contaminants from waters moving through them. Wetlands reduce turbidity and sediment loading and thereby slow the siltation of harbors and navigable rivers and streams (Tiner, 1984). In addition to the habitat and environmental-quality values of wetlands, they also have socioeconomic benefits such as flood- and storm-damage protection, erosion control, public water supply, and production of economically important natural species (Tiner, 1984). Illinois is one of five States whose combined production of peat accounts for over 75 percent of the peat mined in the United States. Wetlands also are the site for many recreational and educational activities including hunting and fishing, nature study, boating, paint- ing and drawing, and photography. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deepwater habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and others, 1979). The distribution of wetlands and deepwater habitats in Illinois is shown in figure 2A', only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Illinois are described below. System Palustrine. Lacustrine Riverine. Figure 1. bwamp along the Cache River in southern Illinois. (Photograph by Michael R. Jeffords, Illinois Natural History Survey.) Wetland description Wetlands in which vegetation is predominantly trees (forested wetlands); shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted, herbaceous plants (persistent- and nonpersistent-emergent wetlands}; or sub- mersed and (or) floating plants (aquatic beds). Also, intermittently to permanently flooded open-water bodies of less than 20 acres in which water is less than 6.6 feet deep. Wetlands within an intermittently to permanently flooded lake or reservoir. Vegetation, when pres- ent, is predominantly nonpersistent emergent plants (nonpersistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds), or both. Wetlands within a channel. Vegetation, when pres- ent, is same as in the Lacustrine System. As of the 1980's, 3.5 percent of Illinois, or about 1.25 million acres, was wetland (Dahl, 1990; Suloway and others, 1992). Most of the State's wetlands are either palustrine emergent wetlands such as marshes and wet prairies or palustrine forested wetlands such as bottom-land hardwood forests and bald cypress swamps. Also, open- water palustrine wetlands primarily farm ponds are present throughout the State (Hubbell, 1987). On the basis of frequency of occurrence, the largest concen- tration of wetlands in Illinois is in the northeast. The largest acre- age of wetlands in Illinois is along the State's major river systems (Hubbell. 1987). Marshes, wet prairies, and bogs (palustrine emer- gent, scrub-shrub, or forested wetlands) are most common in the northeastern part of the State, and bottom-land forests (palustrine forested wetlands) and swamps (palustrine scrub-shrub or forested) are present along Illinois rivers. Dominant plants of marshes are sedges, cattails, and bulrushes. Wet prairie dominants include sedges, cordgrass, and blue flag iris. Silver maple, cottonwood, box elder, red maple, black willow, sy- camore, and bald cypress are characteristic of bottom-land hard- wood forests and swamps in the State. Federally listed endangered species of Illinois wetlands include the eastern prairie white-fringed orchid and decurrent false aster. 180 National Water Summary Wetland Resources: STATE SUMMARIES Chicago WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown. ^^^1 Predominantly wetland Predominantly deepwater habitat B SURFICIAL DEPOSITS ^ Sand and gravel Alluvium US Glacial drift l l Surficial deposits absent Ozark Plateaus Interior Low Plateaus Coastal Plain C PHYSIOGRAPHIC DIVISIONS Figure 2. Wetland distribution in Illinois, physical and climatic features that control wetland distribution in the State, and trends in development of agricultural land. A, Distribution of wetlands and deepwater habitats. 6, Surficial deposits. C, Physiography. (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 1991. B, Voelker and Clarke, 1988; C Physiographic divisions from Fenneman, 1946; landforms data from EROS Data Center) National Water Summary Wetland Resources: ILLINOIS 181 In addition, bald eagles and least terns use bottom lands for habitat (Jerry Bade, U.S. Fish and Wildlife Service, oral commun., 1993). The State of Illinois also maintains a list of endangered species. As of February, 1994, the State list contained 415 endangered species (E) and 96 threatened species (T) about 40 percent of which are wetland dependent. Among the State-listed endangered or threat- ened wetland-plant species are white lady's slipper (E), queen-of- the-prairie (T), water elm (E), and marsh speedwell (T). State-listed animal species include the Illinois chorus frog (T), the Illinois mud turtle (E), sandhill crane (E), black tern (E), bluehead shiner (E), and river otter (E) (Susan Lauzon, Illinois Department of Conser- vation, oral commun., 1994). HYDROLOGIC SETTING Wetlands are present where the geohydrology and physiogra- phy favor the retention of water for extended periods. The location of wetlands in Illinois is strongly affected by its geologic history. Aquifers underlying wetlands in the State are composed of sedimen- tary and metamorphic rocks of various ages overlain by glacial drift. Glacial scouring and subsequent glacial melting at the end of the last ice age left depressions in the glacially derived sediments, or drift, deposited by the glaciers. Glacial drift covers a large area of the State (fig. 2B) and ranges in thickness from a few to several hun- dred feet (Sherrill and others, 1984). The geologic history of the State has significantly shaped its physiography. Most of Illinois lies in the Central Lowland physiographic province (fig. 2C), where the relatively flat topography is due to glaciation. The greatest relief is present where surface drainage has cut into the glacial deposits and, in some locations, into the underlying bedrock. In Illinois, average annual precipitation (fig. 2D) ranges from about 34 inches per year in the north to 48 inches per year in the extreme south (Wendland and others, 1992). About three-fourths of the precipitation that reaches the land surface is returned to the at- mosphere by evaporation and plant transpiration (LaTour and D PRECIPITATION Line of equal average annual precipitation Interval, in inches, is variable Ackermann, 1990). The remaining precipitation recharges the ground- and surface-water systems. Recharge to the shallow ground- water system takes place in interstream areas of the surficial-drain- age system. Aquifers overlain by confining units composed of silt and clay are recharged by precipitation entering areas where the aquifers crop out and by slow percolation downward through the 1930 Figure 2. Continued. D, Average annual precipitation, 1961-90. E, Percentage of agricultural land in Illinois counties in 1850, 1870, 1900, and 1930. (Sources: D, Wendland and others, 1992. E, Data from U.S. Census Office, 1853, 1872, 1901; U.S. Census Bureau, 1932.) 182 National Water Summary Wetland Resources: STATE SUMMARIES confining units. Water returns to the surface as base flow to streams, ponds, and lakes. Ground water moves through shale and dolomite aquifers in fractures or solution channels. Wetlands develop along streams and near glacially formed lakes where ground water dis- charges. In the Central Lowland, wetlands are associated with ground- water discharge into depressions in the extensive glacial drift. In areas of high precipitation, low surface-water gradients coupled with the low permeability of fine-grained surficial deposits can result in poor drainage of glacial depressions. The resulting accumulation of water contributes to wetland formation. Ground-water discharge to streams in the Central Lowland also provides sites for wetland establishment. In the Ozark Plateaus, Interior Low Plateaus, and Coastal Plain, ground water from drift or underlying bedrock discharges primar- ily to streams, as in the Cache River area and the wetlands along the Mississippi River. Wetlands also can form where clay or other fine sediments form a poorly permeable layer that holds water at or near the land surface, providing a suitable habitat for wetland veg- etation. TRENDS Illinois once had vast expanses of wetlands but has lost as much as 90 percent of them (by area) since the 1780's (Dahl, 1990; S.P. Havera, Illinois Natural History Survey, written commun., 1993) sixth in the Nation in terms of percentage loss. A notable example of this loss is the Great Kankakee Swamp (also known as the Grand Marsh). One of the largest marsh-swamp basins in the United States, in the 1830's, this wetland contained more than 1 million acres of wet prairie and marshes (Mitsch and others, 1979). It is now repre- sented in Illinois by a relatively small tract of wetlands along the Kankakee River near Momence. Wetlands in the State have been drained and filled since settle- ment by Europeans began in the 1600's. Of about 8,212,000 acres of wetlands that were present in the 1780's (Havera, 1992), only about 1,254,500 acres remained in the 1980's (Dahl, 1990; Suloway and others, 1992). About 6,000 acres remain undisturbed (White, 1978). Rates of loss in the State are estimated to be between 4,000 and 6,000 acres per year (Illinois Department of Conservation, undated). In Illinois, the major cause of wetland loss has been artificial drainage primarily to make lands suitable for crop production. The number of drained acres in Illinois increased from about 100,000 in the 1870's to nearly 5 million by 1920. Most of the wet- land loss occurred between 1890 and 1930 (S.P. Havera, Illinois Natural History Survey, written commun., 1993). At the end of that period, about 17 percent of land in the State was in drainage dis- tricts (Illinois Tax Commission, 1941), and 27 percent of agricul- tural land had been drained either through district activities or by private action (U.S. Census Bureau, 1981). The percentages of ag- ricultural land in each Illinois county for the years 1850,1870,1900, and 1930 are shown in figure 2E. The rapid and substantial growth in agriculture and the associated expansion of drainage districts in the State during that period paralleled the decline in wetland acre- age as more and more land was drained for farming. Agricultural expansion was not the sole reason for the decline in wetland acreage. The draining of wetlands for housing, transpor- tation, industry, and landfills; stream channelization and dredging for navigation; and reservoir, harbor, and marina construction have also reduced wetland acreage. In addition to acreage loss caused by these activities, wetlands have been degraded by point and nonpoint discharges to surface waters. These discharges are associated with agricultural, industrial, municipal, and urban runoff, which add contaminants and sediment to surface waters. Some wetland acreage has been added through the construc- tion of ponds and reservoirs and through planned wetland construc- tion. In Wadsworth, 35 miles north of Chicago, Wetlands Research, Inc., a nonprofit corporation, is coordinating the Des Plaines River Wetlands Demonstration Project. Since 1983, 50 acres of wetlands have been constructed (Wetlands Research, Inc., 1993). Also, the Cache River Wetlands Project, a joint effort of the Illinois Depart- ment of Conservation, the FWS, The Nature Conservancy, and Ducks Unlimited, has the primary goal of acquiring and restoring between 55,000 and 60,000 acres of contiguous wetland-upland complexes. The impoundment of streams and farm-pond construction, as well as natural processes, also can result in the creation of wetlands. CONSERVATION Many government agencies and private organizations partici- pate in wetland conservation in Illinois. The most active agencies and organizations and some of their activities are listed in table 1. Federal wetland activities. Development activities in Illinois wetlands are regulated by several Federal statutory prohibitions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Harbors Act; the 1972 Clean Water Act and amendments; the 1985 Food Security Act; the 1990 Food, Agriculture, Conservation, and Trade Act; the 1986 Emergency Wetlands Resources Act; and the 1972 Coastal Management Act. Table 1 . Selected wetland-related activities of government agencies and private organizations in Illinois, 1993 [Source: Classification of activities is generalized from information provided by agencies and organizations. », agency or organization participates in wetland-related activity;..., agency or organization does not participate in wetland-related activity. MAN, management; REG, regulation; R&C, resto- ration and creation; LAN, land acquisition; R&D, research and data collec- tion; D&l, delineation and inventory] Agency or organization FEDERAL Department of Agriculture Consolidated Farm Service Agency........................... ... Forest Service ................................................................. ... Natural Resources Conservation Service ................ Department of Commerce National Oceanic and Atmospheric Administration ........................................ Department of Defense Army Corps of Engineers .............................................. Military reservations ..................................................... Department of the Interior Fish and Wildlife Service.............................................. Geological Survey .......................................................... National Biological Service ......................................... ... National Park Service ................................................... ... Environmental Protection Agency.................................. STATE Department of Agriculture............................................... . Department of Conservation........................................... Department of Energy and Natural Resources............................................................. ... ... Department of Mines and Minerals ............................... . Department of Transportation......................................... ... Environmental Protection Agency.................................. Pollution Control Board..................................................... SOME COUNTY AND LOCAL GOVERNMENTS ............. PRIVATE Ducks Unlimited .................................................................. ... The Nature Conservancy.................................................. National Water Summary Wetland Resources: ILLINOIS 183 Section 10 of the Rivers and Harbors Act gives the U.S. Army Corps of Engineers (Corps) authority to regulate certain activities in navigable waters. Regulated activities include diking, deepening, filling, excavating, and placing of structures. The related section 404 of the Clean Water Act is the most often-used Federal legislation protecting wetlands. Under section 404 provisions, the Corps issues permits regulating the discharge of dredged or fill material into wetlands. Permits are subject to review and possible veto by the U.S. Environmental Protection Agency, and the FWS has review and ad- visory roles. Section 401 of the Clean Water Act grants to States and eligible Indian Tribes the authority to approve, apply conditions to, or deny section 404 permit applications on the basis of a pro- posed activity's probable effects on the water quality of a wetland. Most farming, ranching, and silvicultural activities are not sub- ject to section 404 regulation. However, the "Swampbuster" provi- sion of the 1985 Food Security Act and amendments in the 1990 Food, Agriculture, Conservation, and Trade Act discourage (through financial disincentives) the draining, filling, or other alteration of wetlands for agricultural use. The law allows exemptions from pen- alties in some cases, especially if the farmer agrees to restore the altered wetland or other wetlands that have been converted to agri- cultural use. The Wetlands Reserve Program of the 1990 Food, Agriculture, Conservation, and Trade Act authorizes the Federal Government to purchase conservation easements from landowners who agree to protect or restore wetlands. The Consolidated Farm Service Agency (formerly the Agricultural Stabilization and Con- servation Service) administers the Swampbuster provisions and Wet- lands Reserve Program. The Natural Resources Conservation Ser- vice (formerly the Soil Conservation Service) determines compli- ance with Swampbuster provisions and assists farmers in the iden- tification of wetlands and in the development of wetland protection, restoration, or creation plans. The 1986 Emergency Wetlands Resources Act and the 1972 Coastal Zone Management Act and amendments encourage wetland protection through funding incentives. The Emergency Wetland Resources Act requires States to address wetland protection in their Statewide Comprehensive Outdoor Recreation Plans to qualify for Federal funding for State recreational land; the National Park Ser- vice provides guidance to States in developing the wetland compo- nent of their plans. Coastal and Great Lakes States that adopt coastal- zone management programs and plans approved by the National Oceanic and Atmospheric Administration are eligible for Federal funding and technical assistance through the Coastal Zone Manage- ment Act. Illinois has six National Wildlife Refuges with a combined area of nearly 100,000 acres. Goodwin and Niering (1975) evaluated a number of Illinois wetlands for possible registration as National Natural Landmarks. Their list includes nine additional wetland ar- eas comprising about 7,000 acres. State wetland protection. The primary State law governing wetlands is the Interagency Wetland Policy Act of 1989, which sets a goal of no net loss of wetlands due to projects funded by the State. The act is administered through the Illinois Wetland Management Program of the Illinois Department of Conservation. There is also a Floodplain Management Statute under which the Illinois Depart- ment of Transportation issues permits for developments in the 100- year flood plain and for dredging and filling public water bodies. Most regulation of wetlands on private lands takes place at the lo- cal level. Wetlands can be owned and protected by the public as County Forest Preserve Districts. County and local wetland protection. Counties and munici- palities can protect wetlands and other sensitive natural areas ei- ther by acquiring them or by enacting ordinances for their protec- tion. Protection and acquisition are carried out to protect public health, safety, and welfare. One Illinois county has established two wetland banks. These banks have allowed the county to maintain no net loss of wetlands within its boundaries and to provide addi- tional alternatives to developers for compliance with the mitigation requirements of the section 404 program. Two additional counties are investigating a similar banking concept that requires replace- ment of wetlands lost as a result of filling or dredging with wetlands of like kind and quality. Several municipalities in Illinois have spe- cific ordinances protecting wetlands (M.E. Hubbell, Illinois Depart- ment of Conservation, oral commun., 1993). References Cited Barickman, Gene, 1992, Illinois wetlands: The Illinois Steward, Spring 1992, p. 1-5. Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Dahl, I.E., 1990, Wetlands Losses in the United States, 1780's to 1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 13 p. Fenneman, N.M., 1946, Physical divisions of the United States: U.S. Geo- logical Survey special map, scale 1:7,000,000. Goodwin, R.H., and Niering, W.A., 1975, Inland wetlands of the United States evaluated as potential registered natural landmarks: National Park Service Natural History Theme Studies no. 2, 550 p. Havera, S.P., 1992, Waterfowl of Illinois Status and management, Final Federal aid performance report: Cooperative Waterfowl Research W-88-R, 1,035 p. Hubbell, M.E., 1987, Inventory of Illinois wetlands The Illinois wetland management program, in Singh, K.P., Lee, M.T., and Knapp, H.V., eds., Proceedings of the American Water Resources Association Illi- nois section annual conference, Champaign, 111., April 28-29, 1987: Champaign, 111., American Water Resources Association Illinois sec- tion, p. 199-204. Illinois Department of Conservation, undated. A public guide to Illinois wetlands: Springfield, Illinois Department of Conservation, no pagi- nation. Illinois Tax Commission, 1941, Drainage district organization and finance, 1879-1937: Springfield, Illinois Tax Commission, 213 p. LaTour, J.K., and Ackermann, W.C., 1990, Illinois water supply and use, in U.S. Geological Survey, National water summary 1987 Hydrologic events and water supply and use: U.S. Geological Survey Water-Sup- ply Paper 2350, p. 235-242. Mitsch, W.J., Hutchison, M.D., and Paulson, G.A., 1979, The Momence wetlands of the Kankakee River in Illinois An assessment of their value: Illinois Institute of Natural Resources Document 79/17, 55 p. Sherrill, M.G., Lazaro, T.R., and Harbison, L.L., 1985, Illinois ground-water resources, in U.S. Geological Survey, National water summary 1984 Hydrologic events, selected water-quality trends, and ground-water resources: U.S. Geological Survey Water-Supply Paper 2275, p. 199- 204. Suloway, L.B., Hubbell, M.E., and Erickson, Ronald, 1992, Analysis of the wetland resources of Illinois, v. 1 Overview and general results, Report to the Department of Energy and Natural Resources: Spring- field, 111., Department of Energy and Natural Resources, 35 p. Tiner, R.W., Jr., 1984, Wetlands of the United States Current status and trends: Washington, D.C., U.S. Fish and Wildlife Service, 59 p. U.S. Census Bureau, 1932, Fifteenth census of the United States: 1930: Washington, D.C., U.S. Department of Commerce, 1,385 p. ____1981, 1978 Census of Agriculture, v. 1, State and County Data, pt. 13 Illinois: Washington, D.C., U.S. Department of Commerce, 717 p. U.S. Census Office, 1853, Seventh census of the United States, taken in the year 1850: Washington, D.C., U.S. Census Office, 1,022 p. ____1872, Ninth census of the United States, taken in the year 1870, 3 volumes: Washington, D.C., U.S. Census Office, 2,326 p. ____1901, Twelfth census of the United States, taken in the year 1900: Washington, D.C., U.S. Census Office, 1,006 p. Voelker, D.C., and Clarke, R.P., 1988, Illinois ground-water quality, in U.S. Geological Survey, National water summary 1986 Hydrologic events 184 National Water Summary Wetland Resources: STATE SUMMARIES and ground-water quality: U.S. Geological Survey Water-Supply Pa- per 2325, p. 237-244. Wendland, W.M., Kunkel, K.E., Conner, Glen, and others, 1992, Mean 1961-1990 temperature and precipitation over the upper midwest: Illinois State Water Survey Research Report 92-01, 27 p. Wetlands Research, Inc., 1993, "Living laboratory" offers unique research opportunities to improve environmental quality: Chicago, 111., Wet- lands Research, Inc., 11 p. White, John, 1978, Illinois Natural Areas Inventory Survey methods and results: Urbana, 111., Illinois Natural Areas Inventory Technical Report v. 1,426 p. FOR ADDITIONAL INFORMATION: District Chief. U.S. Geological Survey, 102 East Main Street, 4th Floor. Urbana, IL 61801; Regional Wet- land Coordinator, U.S. Fish and Wildlife Service, BHW Federal Building, 1 Federal Drive, Fort Snelling, MN 55112 Prepared by Thomas H. Barringer and Gary O. Balding, U.S. Geological Survey U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources 185 Indiana Wetland Resources We, fetlands cover about 813,000 acres of Indiana (Rolley, 1991) about 3.5 percent of the State. These wetlands support rich biotic communities in freshwater settings across the State, especially in the north and southwest (fig. 1). Wetlands have many chemical, physical, and biological func- tions. Wetlands trap waterborne sediments, nutrients, and toxic chemicals by filtering them out of inflowing water and storing or transforming them. The capacity of wetlands to trap sediment is particularly important in Indiana because surface erosion is a per- sistent, long-term result of intensive agricultural activity. Riparian (streamside) wetlands lessen the severity of floods by storing water temporarily and releasing it gradually, thus reducing flow velocity and delaying and attenuating flood peaks. Vegetation in riparian wetlands helps to maintain stream channels by stabilizing the land surface, and wetlands around lakes act as buffers to erosion from waves. Wetlands provide habitat for waterfowl, fish, other terrestrial and aquatic animals, and a wide variety of plant life. Wetlands pro- vide resting and feeding places on migration routes, as well as food, shelter, breeding areas, and nurseries for many animals, including species of economic interest in Indiana such as muskrat, fish, ducks, and geese. The State has listed 128 wetland-dependent plant spe- cies and over 60 wetland-dependent animal species as endangered, threatened, or of special concern (Indiana Department of Natural Resources, 1989). In Indiana, wetlands have considerable recreational, educa- tional, and economic value. Common activities in and surrounding wetlands are bird-watch ing, hiking, fishing, hunting, swimming, and boating. Wetlands are important to the fur trapping, lumbering, and tourist industries, which benefit the economy of the State. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deep- water habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and oth- ers, 1979). The distribution of wetlands and deepwater habitats in Indiana is shown in figure 2A\ only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Indiana are described below. System Palustrine, Lacustrine Riverine, Figure 1. Cowles Bog in the Great Marsh, Indiana Dunes National Lakeshore. (Photograph by RJ. Shedlock, U.S. Geo- logical Survey.) Wetland description .Wetlands in which vegetation is predominantly trees (forested wetlands); shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted, herbaceous plants (persistent- and nonpersistent-emergent wetlands); or sub- mersed and (or) floating plants (aquatic beds). Also, intermittently to permanently flooded open-water bodies of less than 20 acres in which water is less than 6.6 feet deep. , Wetlands within an intermittently to permanently flooded lake or reservoir. Vegetation, when pres- ent, is predominantly nonpersistent emergent plants (nonpersistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds), or both. . Wetlands within a channel. Vegetation, when pres- ent, is same as in the Lacustrine System. Most Indiana wetlands have been filled or drained. Palustrine wetlands, which are the most abundant wetlands remaining in the State, are distributed throughout Indiana in topographic depressions, between agricultural fields, and in riparian zones along rivers, streams, and lakes. Palustrine forested wetlands are the most com- mon wetlands in Indiana. In the early to mid-1980's, palustrine forested wetlands covered about 504,000 acres, or approximately 62 percent of the wetland area of the State (Rolley, 1991). Palustrine emergent wetlands cov- ered about 143,000 acres (18 percent of total wetland area), and scrub-shrub wetlands covered about 42,000 acres (5 percent). Lacustrine and riverine wetlands covered about 99,000 acres (12 percent). The remaining 3 percent of the wetland area in the State contained mixed or undetermined types of wetland. Most of the wetlands in Indiana are in the north and along river flood plains in the south, particularly the southwest (Rolley, 1991). The northeastern part of the State contains most of Indiana's natu- ral lakes and numerous small, isolated wetlands. The northwestern part of the State includes the Indiana Dunes National Lakeshore, which is on the southern shore of Lake Michigan. Most streams and rivers in Indiana flow to the southwest, where many wetlands are located in the river flood plains of the largest river systems (Indi- ana Department of Natural Resources, written commun., 1993). Wetlands in the rest of the State consist of small, widely scattered wetlands and narrow wetland bands along rivers and streams and around reservoirs (Indiana Department of Environmental Manage- ment, 1991). Indiana has many types of wetlands, most of which are veg- etated. The plant composition of vegetated wetlands is determined by factors such as climate, soil type, ground- and surface-water chemistry, and the extent and duration of flooding. The predomi- nant vegetation or specific location of a wetland frequently deter- 186 National Water Summary Wetland Resources: STATE SUMMARIES mines its common name. Familiar common names for some Indiana wetlands include marsh, wet prairie, swamp, slough, bottom-land hardwood forest, flatwood, bog, fen, kettle, pothole, dune swale, muck flat, and sinkhole pond. Marshes and wet prairies are palus- trine emergent wetlands that contain grasses, sedges, or cattails. Swamps, sloughs, and bottom-land hardwood forests are palustrine forested and scrub-shrub wetlands typically found along rivers. Flatwoods are palustrine forested wetlands that form on level, poorly drained soils where the water table is shallow. Bogs and fens are palustrine wetlands that are generally located in depressions in once- glaciated areas of Indiana; these wetlands generally contain grasses, other soft-stemmed plants, and peat deposits. Kettles and potholes are emergent and scrub-shrub wetlands that formed in depressions left after large blocks of ice that were embedded in glacially depos- ited sediments melted. Dune swales are topographic depressions among sand dunes near Lake Michigan that contain palustrine emergent or scrub-shrub wetlands. Sinkhole ponds are lacustrine wetlands located in plugged sinkholes in areas where limestone bedrock is at or near the surface. HYDROLOGIC SETTING The wetlands of Indiana are formed and maintained by water from precipitation, surface-water runoff, and local and regional ground-water flow systems. Wetlands generally are in topographic lows, where water from surface runoff collects and where ground water commonly discharges after periods of heavy precipitation. Fluctuations in local precipitation and evapotranspiration rates com- bined with local differences in geology, topography, and soil characteristics cause transient or seasonal changes in the way that ground water and surface water interact in a wetland (Meyboom, 1966; Wilcox, 1986; Winter, 1992; Phillips and Shedlock, 1993). Precipitation in Indiana varies seasonally and geographically. Precipitation falls throughout the year but is greatest from March through July (Crompton, 1986). Annual average precipitation ranges from about 36 inches in the northeastern part of the State to about 44 inches in the south-central part. Combined loss from evapora- tion and transpiration is nearly uniform across the State and aver- ages 26 inches annually. Annual surface-water runoff averages about lAXf. M/CHJGrt/V .Indiana Dines National latesticre , Spicer txite Fawn River Fef Marsh take WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown ^^^1 Predominantly wetland Predominantly deepwater habitat fflfflA Area typified by a high density of small wetlands B PHYSIOGRAPHIC REGIONS Northern Zone A. Calumet Lacustrine Plain B. Valparaiso Morainal Area C. Kankakee Outwash and Lacustrine Plain D. Steuben Morainal Lake Area E. Maumee Lacustrine Plain Central Zone F. Tipton Till Plain Southern Zone G. Wabash Lowland H. Crawford Upland I. Mitchell Plain J. Norman Upland K. Scottsburg Lowland L. Muscatatuck Regional Slope M. Dearborn Upland 0 25 50 KILOMETERS Figure 2. Wetland distribution in Indiana and physiography of the State. A, Distribution of wetlands and deepwater habitats. B, Physiography. (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 1991. B, Physiographic divisions modified from Schneider, 1966; landforms data from EROS Data Center.) National Water Summary Wetland Resources: INDIANA 187 A. Glaciated areas of northern Indiana LACUSTRINE WETLANDS PALUSTRINE WETLANDS PALUSTRINE WETLANDS RIVERINE WETLANDS o. Glacial till Glacial till B. Calumet Lacustrine Plain, northwestern Indiana NORTH PALUSTRINE WETLANDS RIVERINE WETLANDS SOUTH Shale and carbonate bedrock C. Riparian wetlands in southern Indiana PALUSTRINE WETLANDS PALUSTRINE WETLANDS -. Bottom-land hardwood forest ',* -> RIVERINE WETLANDS n r i EXPLANATION Direction of ground-water flow Average water table Scrub-shrub vegetation I! \l Emergent vegetation Farmed crops Y Forest vegetation Organic deposits Note: Vertical scale greatly exaggerated Figure 3. Generalized geohydrologic setting of common wetland types in Indiana. A, Wetlands in glaciated areas of northern Indiana. B, Wetlands in the Calumet Lacustrine Plain of northwestern Indiana. C, Riparian wetlands in bedrock areas of southern Indiana. (Sources; A, Modified from Hartke and others, 1975. B, Modified from Shedlock and others, 1993. C, Modified from Gallaher and Price, 1966.) 9.0 inches, and about 3.5 inches recharges the ground- water system (Clark, 1980). The abundant precipita- tion is conducive to the formation and maintenance of wetlands, which were once extensive in Indiana. However, agricultural tile drains, ditches, and straight- ened drainages have substantially reduced the reten- tion of water and, hence, reduced wetland area in many parts of the State. Indiana can be divided into three broad physi- ographic zones based on surficial and bedrock geol- ogy (fig. 2B). The northern zone consists of glacial moraine and areas reworked by water from ancient and present Lake Michigan. The central zone is a flat depositional plain of low relief. The physiography of the southern zone varies and is largely controlled by underlying bedrock. Wetland hydrology differs among and within these zones. In the northern physiographic zone, different local depositional conditions during glacial advances and retreats have resulted in a complex surficial aqui- fer largely composed of till. Till is a heterogeneous mixture of clay, silt, sand, gravel, and boulders thai is deposited directly by and underneath a glacier. The surficial aquifer in the northern zone is connected to deeper aquifer systems in places where the till is thin or missing (Shedlock and others, 1993). Wetlands in this zone generally are in low, poorly drained areas that have standing water (fig. 3A ). The northern zone has five physiographic units: the Valparaiso Morainal Area, the Steuben Morainal Lake Area, the Calumet Lacustrine Plain, the Kankakee Outwash and Lacustrine Plain, and the Maumee Lacustrine Plain (fig. IB). Most of the wet- lands that remain in Indiana are in the Valparaiso Morainal Area and the Steuben Morainal Lake Area. These physiographic units have irregular topography and as much as 200 feet of relief; numerous small, poorly integrated streams; and many closed depres- sions containing lakes and wetlands, including kettles, fens, and bogs. Water is supplied to these wet areas by precipitation, surface-water runoff and, except in bogs, shallow ground-water flow (fig. 3-4). Notable wetlands in these areas are Spicer Lake, Marsh Lake, Laketon Bog, Pinhook Bog, and Fawn River Fen. The Calumet Lacustrine Plain, Kankakee Outwash and Lacustrine Plain, and Maumee Lacus- trine Plain have flat terrain and once contained ex- tensive wetlands in glacial lakes and outwash plains. Land in these physiographic units has been nearly completely ditched and drained. Remaining wetlands in these units are mainly in riparian areas. The ex- ception is the Calumet Lacustrine Plain, which con- tains extensive wetlands in and around the Indiana Dunes National Lakeshore (fig. 3B). In the Calumet Lacustrine Plain, major changes in the level of Lake Michigan occurred as the glaciers receded. Shoreline dune complexes formed sequentially approximately parallel to the modern lakeshore. Each new dune line prevented drainage from the south from reaching the lake directly, resulting in the development of a com- plex wetland system. The wetland system includes Cowles Bog (fig. 1), the largest peatland in Indiana. Peatlands form in depressions where there is poor drainage, standing water, and water chemistry not conducive to plant decay. Plant remains eventually fill the original depression and sometimes rise above the surrounding land surface, forming a peat mound. 188 National Water Summary Wetland Resources: STATE SUMMARIES Cowles Bog, which is sustained in part by ground water and there- fore is by definition a fen, is an example of this process (Wilcox and others, 1986; Shedlock and others, 1993). The wetlands in the In- diana Dunes are the only wetlands in the State where a detailed long- term study (Shedlock and others, 1993) has been completed. The hydrology of both the riparian and the sand-dune wetlands in the Calumet Lacustrine Plain is controlled by precipitation and ground- water flow, primarily in shallow flow systems. The central physiographic zone (fig. 2B) consists of one unit the Tipton Till Plain, which is a nearly flat to gently rolling glacial plain of sandy and silty outwash sediments. At the extreme western edge of the plain, the Wabash River and its tributaries have cut as deep as 150 feet through the glacial deposits into bedrock. The Tipton Till Plain has been almost entirely drained for agricultural purposes. Remaining wetlands are in stream channels, along the edges of reservoirs, and in small, shallow depressions between ag- ricultural fields. These wetlands are maintained by precipitation and local and regional ground-water flow. The southern physiographic zone (fig. 2B) was partly covered by glaciers. There, the surficial aquifer consists of regolith and sedi- mentary deposits of glacial origin. Regolith is unconsolidated, mostly fine-grained material composed of fragmental, weathered bedrock and alluvium overlying unweathered bedrock. The south- ern zone has seven physiographic units: the Wabash Lowland, the Crawford Upland, the Mitchell Plain, the Norman Upland, the Scottsburg Lowland, the Muscatatuck Regional Slope, and the Dearborn Upland. Topography and soils differ considerably among the units and are primarily controlled by the type of underlying bedrock. Most of the wetlands in the southern physiographic zone are in riparian areas along streams and rivers. These wetlands are main- tained by precipitation and local shallow flow systems (fig. 3C). Some of the largest remaining wetlands in Indiana are in the Wabash and Scottsburg Lowlands and on the Muscatatuck Regional Slope. These wetlands are in the flood plains, confluences, and backwater areas of the Wabash, Patoka, White, and Ohio Rivers and their tribu- taries. Notable among these are the flatwoods in the tributaries of the East Fork of the White River, located in the Jefferson Proving Grounds; Little Pigeon Creek Wetland Conservation Area; Twin Swamps; and the Gray Estate and Goose Pond Cypress Sloughs. Unusual wetlands in this zone include those in the Wabash Low- land that have formed in long, narrow surface depressions between spoil piles in areas mined for coal. Also unusual are the sinkhole wetlands and ponds in the Mitchell Plain, formed where vertical solution zones in the carbonate bedrock have become plugged with soil and other debris, and water from precipitation and surface runoff has collected. Additionally, the Jasper-Pulaski Fish and Wildlife Area is a congregating area and migratory rest stop for eastern greater sandhill cranes. TRENDS In the 1780's, before settlement by Europeans, wetlands cov- ered about 5.6 million acres (24 percent) of Indiana (Indiana De- partment of Natural Resources, 1989). At that time, and continuing to the present in some communities, wetlands were categorized as wastelands that could be made more useful by filling and draining. Federal and State laws encouraged these activities (Read. 1993). By the early 1980's, more than 85 percent of the original wetlands in Indiana had been destroyed, and only about 813,000 acres of wet- lands remained (Rolley, 1991). About 85 percent of vegetated-wet- land losses resulted from conversion of wetlands for agricultural purposes (Indiana Department of Natural Resources, 1989). Agricultural, industrial, and residential-development interests in Indiana still encourage stream channelization and ditching, drain- ing, filling, diking, dredging, and damming of wetlands. In addi- tion to the direct loss of wetlands, the biological value of many natu- ral wetlands has been degraded by contamination by excess nutri- ents, sediments, and toxic chemicals as well as by the spread of nonnative plant species that can eliminate native species. The loss and degradation of wetlands and resulting adverse effects on fish and wildlife populations have reduced recreational opportunities and the economic benefits that outdoor recreation can bring to local communities (Indiana Department of Natural Resources, written commun., 1993). About 1 to 3 percent of Indiana's remaining wetlands are lost each year, primarily because of drainage for agricultural purposes (Indiana Division of Fish and Wildlife, written commun., 1993). A survey of wetlands in the northern one-third of Indiana indicated that by 1987, more than 10 percent of the wetlands in aerial photo- graphs taken between 1981 and 19 84 of the nor them physiographic zone and Wabash River watershed had been drained (Indiana De- partment of Natural Resources, 1989). Construction of flood-control reservoirs in the 1960's and 1970's doubled the acreage of open water by permanently flooding riparian zones along rivers. Lacustrine wetlands replaced the natu- rally occurring riverine and palustrine wetlands in the process. In fact, approximately 70 percent of existing lacustrine wetlands and 13 percent of palustrine wetlands in Indiana developed as the re- sult of damming or excavation (Rolley, 1991). In addition, some new wetlands have formed in reclaimed and unreclaimed spoil areas in coal-mining zones. However, wetland losses in Indiana have been far greater than wetland gains. To slow the rate of wetland loss, recent State and Federal laws require or encourage wetland protection or creation. For example, wetlands have been created by the establishment of compensatory wetland mitigation sites, especially for transportation-related projects. Regulations require that 3 acres be created for each acre destroyed, but the actual success rate is probably much lower (In- diana Department of Natural Resources, 1989). The Indiana tax code encourages wetland protection for sites larger than 10 acres. Some farmers have used provisions in Federal wetlands-related leg- islation to consolidate existing wetlands and create new ones (Indi- ana Department of Natural Resources, 1989). Some municipalities are invoking waste- and stormwater-management regulations to encourage the protection and development of wetlands. River Basin Commissions, notably those of the Kankakee, Maumee, and St. Joseph Rivers, are encouraging or pursuing wetland restoration as a flood-control measure that would have the added benefit of recre- ation potential. In addition, the Indiana Department of Natural Resources, FWS, and the Natural Resources Conservation Service (NRCS; formerly known as the Soil Conservation Service) have re- stored more than 600 wetlands totaling 3,000 acres and constructed many other wetlands under the Partners for Wildlife program. Wet- land protection efforts are adversely affected by limited public un- derstanding of wetland values, lack of information on wetland dis- tribution and abundance in the State, and insufficient and unen- forced legislation (Indiana Department of Natural Resources, writ- ten commun., 1993). CONSERVATION Many government agencies and private organizations partici- pate in wetland conservation in Indiana. The most active agencies and organizations and some of their activities are listed in table 1. Federal wetland activities. Development activities in Indi- ana wetlands are regulated by several Federal statutory prohibitions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Har- bors Act; the 1972 Clean Water Act and amendments; the 1985 Food National Water Summary Wetland Resources: INDIANA 189 Table 1. Selected wetland-related activities of government cultural use. The Wetlands Reserve Program of the 1990 Food, agencies and private organizations in Indiana, 1993 Agriculture, Conservation, and Trade Act authorizes the Federal [Source: Classification of activities is generalized from information provided Government to purchase conservation easements from landowners by agencies and organizations. , agency or organization participates in who agree to protect or restore wetlands. The Consolidated Farm wetland-related activity;..., agency or organization does not participate in Service Agency (formerly the Agricultural Stabilization and Con- wetland-related activity. MAN, management; REG, regulation; R&C, resto- ° . , . . . , 0 i j ration and creation; LAN, land acquisition; R&D, research and data collec- servation Service) administers the Swampbuster provisions and tion; D&l, delineation and inventory] Wetlands Reserve Program. The NRCS determines compliance with _______________________________________ Swampbuster provisions and assists farmers in the identification of ^ <s <^ ^ <^ \ wetlands and in the development of wetland protection, restoration, Agency or organization ^ <^ ^ ^ ^ Sr or creation plans. FEDERAL ^ne ^6 Emergency Wetlands Resources Act and the 1972 Department of Agriculture Coastal Zone Management Act and amendments encourage wetland Consolidated Farm Service Agency........................... ... ... ... protection through funding incentives. The Emergency Wetland Natural Resources Conservation Service ................ Resources Act requires States to address wetland protection in their Department of Commerce Statewide Comprehensive Outdoor Recreation Plans to qualify for National Oceanic and Atmospheric Federal funding for State recreational land; the National Park Ser- Admmistration................................................................. . i -. n * j i it. *i j Department of Defense vice Provldes guidance to States in developing the wetland compo- ArmyCorpsof Engineers .............................................. nent of their plans. Coastal and Great Lakes States that adopt coastal- Department of the Interior zone management programs and plans approved by the National Fish and Wildlife Service.............................................. Oceanic and Atmospheric Administration are eligible for Federal Geological Survey.......................................................... funding and technical assistance through the Coastal Zone Manage- National Biological Service......................................... ... ... ... ... t A t National Park Service ................................................... ........ mentAct. Environmental Protection Agency.................................. . . . State wetland activities. Currently (1993), no Indiana law STATE specifically regulates activities in wetlands, although the Depart- Department of Environmental Management................ . ... ... .. . mentof Natural Resources is developing a State wetland conserva- Department of Natural Resources ................................. ...... tion plan under a grant from the EPA. The scheduled completion date lnd,ana Geological Survey............................................... . f h , { mid-1995. Regulation and management of Indiana Indiana University f , , , T ,. ~ ,, . , School of Public and Environmental Affairs............. . . wetlands are performed under the Indiana Water Pollution Control Purdue University Law, sections 401 and 404 of the Federal Clean Water Act, the In- Department of Forestry and Natural Resources..... .. . . diana Flood Control Act, the Indiana Preservation of Lakes Stat- State Highway Administration......................................... ... ..... ute, the Indiana Nature Preserves Act, and the Indiana Wetland pSlvISVN^TlONS 1 BOVERNMENTC ' ' ' ConservationProgram.ThelndianaDepartmentofEnvironmental Ducks Unlimited ... Management and the Indiana Department of Natural Resources are Hoosier Environmental Council................................... . the principal State agencies that administer the laws and associated IzaakWalton League ..................................................... ... permit programs. Save the Dunes Council................................................ The Indiana Water Pollution Control Law gives the Department Sierra Club ....................................................................... . of Environmental Management authority to protect wetlands, which The Nature Conservancy.............................................. . . . . f. , ., c . ,, f , . ... .-., <* are defined as waters of the State for this purpose. Section 401 of the Federal Clean Water Act authorizes the Department of Environ- mental Management's water-quality certification program. Corps section 404 dredge-and-fill applications are reviewed both by the Security Act; the 1990 Food, Agriculture, Conservation, and Trade Department of Environmental Management to determine whether Act; the 1986 Emergency Wetlands Resources Act; and the 1972 the proposed activities will adversely affect water quality and by Coastal Zone Management Act. the Department of Natural Resources for comment on potential Section 10 of the Rivers and Harbors Act gives the U.S. Army environmental impacts and habitat disturbance. The Indiana Flood Corps of Engineers (Corps) authority to regulate certain activities Control Act requires a Construction in the Floodway Permit from in navigable waters. Regulated activities include diking, deepening, the Department of Natural Resources in order to construct within filling, excavating, and placing of structures. The related section 404 the floodway of a river or stream and its adjacent wetlands. The of the Clean Water Act is the most often-used Federal legislation Indiana Preservation of Lakes Statute requires a permit from the protecting wetlands. Under section 404 provisions, the Corps issues Department of Natural Resources to change the water level or alter permits regulating the discharge of dredged or fill material into the shoreline or bed of a public freshwater lake. The Indiana Na- wetlands. Permits are subject to review and possible veto by the U.S. ture Preserves Act established the Division of Nature Preserves Environmental Protection Agency (EPA), and the FWS has review and within the Department of Natura] Resources; the Division is respon- advisory roles. Section 401 of the Clean Water Act grants to States sible for the inventory, acquisition, dedication, management, and and eligible Indian Tribes the authority to approve, apply conditions protection of significant natural areas throughout the State, includ- to, or deny section 404 permit applications on the basis of a pro- ing wetlands, but the program's strict criteria eliminate many wet- posed activity's probable effects on the water quality of a wetland. lands from consideration. The Division of Fish and Wildlife of the Most farming, ranching, and silviculture activities are not sub- Department of Natural Resources administers the Indiana Wetland ject to section 404 regulation. However, the "Swampbuster" provi- Conservation Program, which also protects and manages "signifi- sion of the 1985 Food Security Act and amendments in the 1990 cant" wetlands in 20 areas (totaling 5,409 acres) acquired by dona- Food, Agriculture, Conservation, and Trade Act discourage (through tion, by purchase, or as compensation for loss resulting from per- financial disincentives) the draining, filling, or other alteration of mit violation. wetlands for agricultural use. The law allows exemptions from pen- Other State wetland-management activities of the Division of allies in some cases, especially if the farmer agrees to restore the Fish and Wildlife include several projects in partnership with Fed- altered wetland or other wetlands that have been converted to agri- eral, other State, and private agencies to conserve and restore wet- 190 National Water Summary Wetland Resources: STATE SUMMARIES lands for wildlife habitat. In addition, the Division administers rec- reation and conservation areas directly and performs management activities in about 364,000 acres, mostly lakes and rivers. County and local wetland activities. Several counties are developing wetland programs. For example, LaGrange County in northeastern Indiana is developing a water-treatment process that uses created wetlands to protect its natural lakes and streams. Private wetland organization activities. Several private or- ganizations in Indiana are active in the development of wetland regu- lations, policy planning, advocacy, land acquisition and manage- ment, environmental education, and research. A few of the many private organizations active in wetlands issues in the State are The Nature Conservancy, whose primary wetland activities are acqui- sition, preservation, and management of wetland areas and associ- ated watersheds; the Sierra Club, which has established the Wet- lands Project, an information network to connect individuals, groups, and agencies working on wetland conservation and resto- ration; Ducks Unlimited, which supports the conservation and cre- ation of waterfowl habitat; and the Izaak Walton League, the Save the Dunes Council, and the Hoosier Environmental Council, which support public education and efforts to enact wetland protection legislation. References Cited Clark, G.D., ed., 1980, The Indiana water resource: Indianapolis, Indiana Department of Natural Resources, v. I, 508 p.; v. II, 94 p. Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Report FWS/OBS-79/31, 131 p. Crompton, E.J., 1986. Indiana surface-water resources, in U.S. Geological Survey, National water summary 1985 Hydrologic events and sur- face-water resources: U.S. Geological Survey Water-Supply Paper 2300, p. 223-228. Gallaher, J.T., and Price, WE., Jr., 1966, Hydrology of the alluvial deposits in the Ohio River valley in Kentucky: U.S. Geological Survey Water- Supply Paper 1818, 80 p. Hartke, E.J., Hill, J.R., and Reshkin, Mark, 1975, Environmental geology of Lake and Porter Counties, Indiana An aid to planning: Indiana Department of Natural Resources, Indiana Geological Survey Special Report 11, Environmental Study 8, 57 p. Indiana Department of Environmental Management, 1991, Indiana 305(b) report, 1990-1991: Indianapolis, Ind., Office of Water Management, p. 1-20. Indiana Department of Natural Resources, 1989, Wetlands...Indiana's en- dangered natural resource, an appendix to Indiana outdoor recreation 1989 An assessment and policy plan: Indianapolis, Ind., Department of Natural Resources, Division of Outdoor Recreation, 19 p. Meyboom, Peter, 1966, Unsteady groundwater flow near a willow ring in hummocky moraine: Journal of Hydrology, v. 4, p. 38-62. Phillips, P.J., and Shedlock, R.J., 1993, Hydrology and chemistry of ground- water and seasonal ponds in the Atlantic Coastal Plain in Delaware, U.S.A.: Journal of Hydrology, v. 141, p. 157-178. Read, C.J., 1993, Swamped, in Werner, P., ed., The wetlander: Indianapo- lis, Ind., Sierra Club Wetlands Project, v. 2, no. 1, p. 5. Rolley, R.E., 1991, Indiana's wetland inventory: Department of Natural Resources, Division of Fish and Wildlife, Wildlife Management and Research Notes 532, 6 p. Schneider, A.F., 1966, Physiography, in Lindsey, A.A., ed., Natural features of Indiana: Indianapolis, Indiana Academy of Science, p. 40-56. Shedlock, R.J., Wilcox, D.A., Thompson, T.A., and Cohen, D.A., 1993, Interactions between ground water and wetlands, southern shore of Lake Michigan, USA: Journal of Hydrology, v. 141, p. 127-155. Wilcox, D.A., 1986, The effects of deicing salts of water chemistry in Pinhook Bog, Indiana: Water Resources Bulletin, v. 22, no. 1, p. 57- 65. Wilcox, D.A., Shedlock, R.J., and Hendrickson, W.H., 1986, Hydrology, water chemistry and ecological relations in the raised mound of Cowles Bog: Journal of Ecology, v. 74, p. 1,103-1,117. Winter, T.C., 1992, A physiographic and climatic framework for hydrologic studies of wetlands, in Robarts, R.D., and Bothwell, M.L., eds., Pro- ceedings of the Symposium on Aquatic Ecosystems in Semi-Arid Regions, 1990: Saskatoon, Saskatchewan, Environment Canada, The National Hydrology Research Institute Symposium Series 7. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Sur- vey, 5957 Lakeside Boulevard, Indianapolis, IN 46278; Regional Wetland Coordinator, U.S. Fish and Wildlife Service, BHW Federal Building, 1 Federal Drive, Fort Snelling, MN 55111 Prepared by Martha A. Hayes, U.S. Geological Survey U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources 191 Iowa Wetland Resources We'etlands provide many benefits, such as attenuating flood-peak discharges, stabilizing streambanks, and improving water quality by trapping suspended sediment and accumulating or transforming some types of chemical contaminants. Wetlands also are valuable for fish and wildlife habitat. Publicly owned wetland areas provide diverse recreational opportunities. Wetlands cover about 1.2 percent of Iowa. However, about 200 years ago more than 11 percent of the State was wetlands (Dahl, 1990), and they were once a conspicuous feature on the prairie land- scape (fig. 1). Fertile soils and abundant wildlife associated with the prairie and its wetlands were attractions for early settlers. How- ever, when farming became a way of life for the settlers, wetlands came to be considered obstacles. Today, wetlands are considered by many residents to be valuable resources and important reminders of Iowa's natural heritage. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deepwater habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and others, 1979). The distribution of wetlands and deepwater habitats in Iowa is shown in figure 2A; only wetlands are discussed herein. Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Iowa are described below. System Palustrine. Lacustrine Wetland description Wetlands in which vegetation is predominantly trees (forested wetlands); shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted, herbaceous plants {persistent- and nonpersistent-emergent wetlands); or sub- mersed and (or) floating plants {aquatic beds}. Also, intermittently to permanently flooded open-water bodies of less than 20 acres in which water is less than 6.6 feet deep. . Wetlands within an intermittently to permanently flooded lake or reservoir. Vegetation, when pres- ent, is predominantly nonpersistent emergent plants {nonpersistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds), or both. . Wetlands within a channel. Vegetation, when pres- ent, is same as in the Lacustrine System. Dahl (1990) estimated that Iowa has about 421,900 wetland acres. Several types of wetlands are present throughout Iowa. Prairie-pothole marshes (emergent wetlands), swamps (forested wet- lands), sloughs, bogs (emergent wetlands), wet meadows (emergent wetlands), fens (emergent and scrub-shrub wetlands), and small ponds are examples of palustrine wetlands. The Lacustrine System includes large oxbows, natural lakes, and reservoirs. The Riverine System includes streams and rivers. Riverine, Prairie-pothole marshes are a familiar type of Iowa wetland. These wetlands occur in the area of latest glaciation of Iowa (fig. 2B). Most of the naturally occurring lakes in Iowa also are in this area. Bishop (1981) estimated that there are about 36,500 acres of natural and artificial prairie-pothole marshes in Iowa. Other wetlands in Iowa are associated with rivers in the inte- rior and on the eastern and western borders of the State. The wet- lands formerly associated with the Missouri River are examples of wetlands that have been lost due to channelization, whereas many of the wetlands along the Mississippi River were created as a result of lock and dam construction (Iowa Department of Natural Re- sources, 1988). About 380,000 acres of wetlands are associated with the rivers and streams of Iowa; most, about 324,785 acres, are along the rivers that border the State (Bishop, 1981). Small wetlands oc- cur in scattered areas throughout Iowa where ground-water dis- charge maintains a supply of water that allows wetland vegetation to develop or where poor surface drainage results in ponding of water. HYDROLOGIC SETTING Wetlands form in areas where there is persistent water at or near the land surface. Palustrine wetlands in Iowa occur mainly in shallow depressions on the land surface. Lacustrine and riverine wetlands occur within deeper water lakes or within the channels of streams, respectively. The interaction between surface water and ground water within palustrine wetlands is complex. Winter (1989) describes several hydrologic settings of wetlands in the northern prairie, including wetlands in the area of the most recent glaciation in Iowa (fig. 26). Most of the northern-prairie wetlands occur in depressions on the land surface. These depressions, which occur at various positions on the landscape (fig. 3), were formed by processes related to gla- cial advances and deposition, slumping, deformation, and collapse as ice melted (Prior, 1991). The landscape where these depressions occur is characterized by glacial deposits that are low in permeabil- ity and that have a gradual regional land-surface slope. The depres- sions do not contribute to surface runoff unless the water they con- tain breaches local drainage divides separating them from adjacent depressions (Winter, 1989). Figure 1. Prairie-pothole marsh at Freda Haffner Kettlehole State Preserve, Iowa. (Photograph by Jean Prior, Iowa Department of Natural Resources.) 192 National Water Summary Wetland Resources: STATE SUMMARIES Ponded water in northern-prairie wetlands usually is continu- ous with the water table in the glacial deposits (fig. 3). Wetlands in relatively high topographic positions (fig. 3) recharge ground wa- ter through the infiltration of rainfall, snowmelt, and local surface runoff. Discharge is through evapotranspiration and lateral and downward ground-water flow. These topographically higher wet- lands depend on adequate precipitation to maintain their supply of water and are among the first wetland areas to dry up during drought. Ground water from elevated sources can discharge to lower areas (fig. 3). The lower depressions also can receive surface run- off. Water in these depressions occurs either as ponded water or as ground water just below the land surface. Discharge typically is by evapotranspiration. Topographically low wetlands are less susceptible to short-term drought because ground water can continue to flow to them as long as the adja- g cent water table is higher. Some depressions occur at intermediate positions on the landscape (fig. 3). Ground water can enter these depressions from higher areas and exit by re infiltrating to ground water. In some wetlands on level land that normally receive ground-water discharge, an increase in water level to above the water table results in re- charge to the ground-water system until evapotranspi- ration lowers the water level in the wetland and ground- water discharge resumes. Palustrine wetlands in the flood plains of rivers occur in depressions and other low-lying areas, such as meander scars and stream channels. Water sources for these wetlands include precipitation, ground-water discharge, and stream overflows. Wa- ter loss from these wetlands is by evapotranspiration and ground- water flow. Fens and seeps are wetlands that form on hillslopes where ground-water discharge maintains a source of water to wetland veg- etation (Prior, 1991). These wetlands form at the hillside exposures of permeable materials that transmit ground water to the land sur- face (Thompson and others, 1992). Fens and seeps are similar to springs except that the small flow rates do not result in surface run- off. GLACIATION Glacial extent during most recent glacial maximum Upper Mississippi Wildlife and FMi Refuge WETLANDS AND DEEPWATER HABITATS , 0 25 50 KiLOMETERS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown ^^^1 Predominantly wetland Predominantly deepwater habitat [j^j^j Area typified by a high density of small wetlands Figure 2. Wetland distribution in Iowa and extent of most recent glaciation. A, Distribution of wetlands and deepwater habitats. B, Extent of most recent glaciation. (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 1991. B, Prior, 1991.) National Water Summary Wetland Resources: IOWA 193 TRENDS The FWS has estimated that Iowa lost 89 percent of its wetland area more than 3.5 million acres between the 1780's and the 1980's (Dahl, 1990). This percentage ranks third in the Nation for loss of wetlands; only California and Ohio have had greater percent- age losses. The number of acres lost during the same time period was exceeded by 15 other States. The Iowa Department of Natural Resources estimates that about 97.5 percent of Iowa's presettlement wetlands has been lost; 36,852 acres remain (Iowa Department of Natural Resources, 1990). The large difference in the wetland-area estimates by different agen- cies probably is due, in part, to differences in classification crite- ria. However, both estimates indicate the large magnitude of wet- land loss that has occurred in Iowa during the past 200 years. The primary cause of wetland loss has been agricultural de- velopment (Iowa Department of Natural Resources, 1990). Prairie potholes have been converted to farmland by draining. The drain- age has been accomplished by constructing ditches to remove ponded water and installing subsurface drainage tile to lower the water table (Bishop, 1981). Some drained wetlands can be restored by removal or modification of the drainage system. Wetland losses on flood plains are the result of stream channelization, flood control, and filling. Channelization can pro- duce shorter, higher gradient stream segments, which results in a declining water table beneath the flood plain. Flood control, either by construction of reservoirs or dikes, reduces the potential for streams to overflow and recharge flood-plain depressions. Filling eliminates the depressions in which water accumulates. The Mis- souri River near Sioux City, Iowa, is an example of a stream seg- ment that has been channelized and straightened. At Sioux City, the stream-water level has been lowered about 9 feet by channelization and construction of a reservoir on the Missouri River about 60 miles upstream. Buchmiller (1986) showed that water levels in wetlands on the flood plain responded directly to changes in the water level of the Missouri River. The trend in wetland loss might be reversing. The Iowa De- partment of Natural Resources reported an increase of 1,852 wet- land acres between 1987 and 1990 as a result of a five-State joint Federal, State, county, and private-organization program (Iowa Department of Natural Resources, 1990). The program, Prairie Pothole Joint Venture, hopes to acquire 2,000 acres of land in Iowa and restore 150 wetland areas per year (Iowa Department of Natu- ral Resources, 1992). Many wetland acres are potential additions under the Wetlands Reserve Program of the 1990 Food, Agricul- ture, Conservation, and Trade Act, The Wetlands Reserve Program FLOW-THROUGH WETLAND DISCHARGE WETLAND ^THROUGH WETLAND EXPLANATION Direction of ground-water flow Average water table Figure 3. Subsurface hydrology of northern-prairie wetlands. (Source: Modified from Winter, 1992.) was created to purchase easements on private land to protect wet- lands that otherwise can be lost to agricultural development. Additional increases in wetland area are occurring as a result of reservoir construction in Iowa. Small soil-conservation structures and recreational reservoirs have been constructed in steep, typically well-drained terrain that originally might not have contained wet- lands. The impoundment of water behind these structures can lead to increases in palustrine and lacustrine wetlands. However, the number of additional acres resulting from impoundment is expected to be small compared to the potential additions under the Wetlands Reserve Program (Jim Ayen, Soil Conservation Service, oral com- mun., 1992). CONSERVATION Many government agencies and private organizations partici- pate in wetland conservation in Iowa. The most active agencies and organizations and some of their activities are listed in table 1. Federal wetland activities. Development activities in Iowa wetlands are regulated by several Federal statutory prohibitions and incentives that are intended to slow wetland losses. Some of the more important of these are contained in the 1899 Rivers and Harbors Act; the 1972 Clean Water Act and amendments; the 1985 Food Security Act; the 1990 Food, Agriculture, Conservation, and Trade Act; and the 1986 Emergency Wetlands Resources Act. Section 10 of the Rivers and Harbors Act gives the U.S. Army Corps of Engineers (Corps) authority to regulate certain activities in navigable waters. Regulated activities include diking, deepening, filling, excavating, and placing of structures. The related section 404 of the Clean Water Act is the most often-used Federal legislation protecting wetlands. Under section 404 provisions, the Corps issues permits regulating the discharge of dredged or fill material into wetlands. Permits are subject to review and possible veto by the U.S. Environmental Protection Agency (EPA), and the FWS has review and advisory roles. Section 401 of the Clean Water Act grants to States and eligible Indian Tribes the authority to approve, apply conditions to, or deny section 404 permit applications on the basis of a pro- posed activity's probable effects on the water quality of a wetland. Most farming, ranching, and silviculture activities are not sub- ject to section 404 regulation. However, the "Swampbuster" provi- sion of the 1985 Food Security Act and amendments in the 1990 Food, Agriculture, Conservation, and Trade Act discourages (through financial disincentives) the draining, filling, or other al- teration of wetlands for agricultural use. The law allows exemptions from penalties in some cases, especially if the farmer agrees to re- store the altered wetland or other wetlands that have been converted to agricultural use. The Wetlands Reserve Program of the 1990 Food, Agriculture, Conservation, and Trade Act authorizes the Federal Government to purchase conservation easements from landowners who agree to protect or restore wetlands. The Consolidated Farm Service Agency (formerly the Agricultural Stabiliza- tion and Conservation Service) administers the Swampbuster provisions and Wetlands Reserve Pro- gram. The Natural Resources Conservation Service (formerly the Soil Conservation Service) determines compliance with Swampbuster provisions and assists farmers in the identification of wetlands and in the development of wetland protection, restoration, or cre- ation plans. The 1986 Emergency Wetlands Resources Act encourages wetland protection through funding incen- tives. The act requires States to address wetland pro- tection in their Statewide Comprehensive Outdoor Recreation Plans to qualify for Federal funding for State recreational land; the National Park Service pro- vides guidance to States in developing the wetland DISCHARGE WETLAND 194 National Water Summary Wetland Resources: STATE SUMMARIES Table 1 . Selected wetland-related activities of government agencies and private organizations in Iowa, 1993 [Source: Classification of activities is generalized from information provided by agencies and organizations. , agency or organization participates in wetland-related activity;..., agency or organization does not participate in wetland-related activity. MAN, management; REG, regulation; R&C, restora- tion and creation; LAN, land acquisition; R&D, research and data collection; D&l, delineation and inventory] Agency or organization FEDERAL Department of Agriculture Consolidated Farm Service Agency............... Natural Resources Conservation Service .... Department of Defense Army Corps of Engineers .................................. Department of the Interior Fish and Wildlife Service .................................. Geological Survey.............................................. National Biological Service............................. National Park Service ....................................... Environmental Protection Agency...................... STATE Department of Natural Resources Energy and Geological Resources Division.. Environmental Protection Division ................. Fish and Wildlife Division ................................. Parks, Recreation, and Preserves Division .. Department of Transportation............................. Iowa State University Leopold Center for Sustainable Agriculture , University of Iowa Hygienic Laboratory........................................... SOME COUNTY AND LOCAL GOVERNMENTS . PRIVATE ORGANIZATIONS Ducks Unlimited...................................................... Iowa Natural Heritage Foundation..................... Pheasants Forever................................................. The Nature Conservancy...................................... component of their plans. In addition to its regulatory responsibilities, EPA provides fi- nancial assistance for special studies, development of wetland in- ventories, and other resource-management tools. Technical assis- tance is available to agencies and the public for wetland-delineation training, project consultation, and public education. The EPA over- sees the State's development and implementation of water-quality standards that apply to surface waters, including wetlands. Two agencies have responsibilities for management of most Federal wetlands in Iowa. The Corps has responsibility for about 217,000 acres of land that includes wetlands in areas of Federal flood-con- trol projects. The principal areas of these wetlands are along the Mississippi River and the four interior flood-control reservoirs in Iowa (Lake Red Rock, Saylorville Lake, Coralville Lake, and Rathbun Lake). The FWS manages land at five National Wildlife Refuges (NWR) that contain wetlands: Upper Mississippi River Wild- life and Fish Refuge, Mark Twain NWR, Union Slough NWR, Desoto Bend NWR, and Walnut Creek NWR. The NFS manages a small amount of wetland area at Effigy Mounds National Monument. State wetland activities. The principal wetlands-management agency in Iowa is the Iowa Department of Natural Resources. The Department manages more than 250,000 acres of public and some privately owned wetlands. The Department also is responsible for implementing Federal wetlands initiatives, such as the North Ameri- can Waterfowl Management Plan. The Environmental Protection Division of the Department of Natural Resources is responsible for State regulatory actions. The State directly regulates wetlands un- der provisions of section 401 of the Clean Water Act, and some wetlands are protected for certain uses of water (Iowa Department of Natural Resources, 1990). The Iowa Department of Transporta- tion manages small areas of wetlands within highway rights-of-way. The Department also identifies wetland areas that might be affected by construction projects and can acquire land and create additional wetlands to mitigate wetland loss resulting from construction projects. County and local wetland activities. Wetland management, restoration and creation, land acquisition, and delineation and in- ventory are being conducted by some county and local governments. The principal agencies involved are the county conservation boards. The extent of activity differs from one county to another. Private wetland activities. Several nonprofit private organi- zations are involved in wetland activities in Iowa. Ducks Unlimited, the Iowa Natural Heritage Foundation, and Pheasants Forever are partners with Federal, State, and local governments in raising funds for wetland acquisition and restoration. Although land is acquired by these organizations, typically it is sold or transferred to public agencies for management purposes. The Nature Conservancy also is active in acquiring land for preservation of endangered plant and animal species as well as ecologically unique habitats. Some of these land acquisitions contain wetlands. References Cited Bishop, R.A., 1981, Iowa's wetlands: Proceedings of the Iowa Academy of Science, v. 88, no. 1, p. 11-16. Buchmiller, R.C., 1986, Hydrologic reconnaissance and summary of exist- ing data on surface and ground-water resources in the Missouri River valley in Woodbury and Monona Counties, Iowa, 1985: U.S. Geologi- cal Survey Open-File Report 86-144, 21 p. Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, E.T., 1979, Clas- sification of wetlands and deepwater habitats of the United States: Vvashington, D.C., U.S. Fish and Wildlife Service Report, FWS/OBS- 79/31, 131 p. Dahl, T.E., 1990, Wetlands Losses in the United States, 1780 s to 1980's: Washington, D.C., U.S. Fish and Wildlife Service Report to Congress, 13 p. Iowa Department of Natural Resources, 1988, Iowa wetlands protection plan A supplement to the Iowa statewide comprehensive outdoor recreation plan: Des Moines, Iowa Department of Natural Resources, lip. ____1990, Water quality in Iowa during 1988 and 1989: Des Moines, Iowa Department of Natural Resources, p. 3-69 and 3-70. ____1992, Iowa prairie pothole joint venture 1991 status report: Des Moines, Iowa Department of Natural Resources, 4 p. Prior, J.C., 1991, Landforms of Iowa: Iowa City, University of Iowa Press, 153 p. Thompson, C.A., Bettis III, E.A., and Baker, R.G., 1992, Geology of Iowa fens: Journal of Iowa Academy of Science, v. 99, no. 2-3, p. 53-59. Winter, T.C., 1989, Hydrologic studies of wetlands in the northern prairie, in van der Valk, Arnold, ed., Northern prairie wetlands: Ames, Iowa State University Press, p. 16-54. Winter, T.C., 1992, A physiographic and climatic framework for hydrologic studies of wetlands, in Robarts, R.D., and Bothwell, M.L., eds., Pro- ceedings of the Symposium on Aquatic Ecosystems in Semi-arid Regions Implications for resource management: Saskatoon, Saskatchewan, Environment Canada, The National Hydrology Re- search Institute Symposium Series 7, p. 127-148. FOR ADDITIONAL INFORMATION: District Chief, U.S. Geological Survey, P.O. Box 1230, Iowa City, IA 52244; Regional Wetland Coordina- tor, U.S. Fish and Wildlife Service, BHW Building, I Federal Drive, Fort Snelling, ,MN55111 Prepared by Robert C. Buchmiller, U.S. Geological Survey U.S. Geological Survey Water-Supply Paper 2425 National Water Summary Wetland Resources 195 Kansas Wetland Resources Kaimsas once was covered by an estimated 841,000 acres of wet- lands; of that area about 435,400 acres, or 0.8 percent of the State's area, remain (Dahl, 1990). Wetlands in Kansas represent some of the last aquatic areas available for wildlife and plants. Wetlands provide habitat for many species of birds, fish, mammals, reptiles, and invertebrates. Kansas wetlands are particularly important to migratory waterfowl and shorebirds, which depend on the few re- maining wetlands in the Central Flyway for food, water, and cover during their seasonal migrations. Cheyenne Bottoms (fig. 1), a large freshwater marsh in central Kansas, is considered the most impor- tant migration staging point for shorebirds in North America (Wentz, 1988). Cheyenne Bottoms also provides habitat for five nationally threatened or endangered species bald eagle, peregrine falcon, least tern, piping plover, and whooping crane (Kansas Biological Survey and Kansas Geological Survey, 1987). Kansas wetlands are valuable for their hydrologic functions. By attenuating flood peaks and storing floodwaters, wetlands can protect adjacent and downstream property from flood damage and help control erosion. Wetlands also have important water-quality functions, including silt removal, mineral uptake, and nutrient trans- formation. Kansas wetlands also are important for recreation, tour- ism, and esthetic and educational benefits. TYPES AND DISTRIBUTION Wetlands are lands transitional between terrestrial and deep- water habitats where the water table usually is at or near the land surface or the land is covered by shallow water (Cowardin and oth- ers, 1979). The distribution of wetlands and deepwater habitats in Kansas is shown in figure 2A; only wetlands are discussed herein. Figure 1. Blue-winged teal at Cheyenne Bottoms in central Kansas. (Photograph by Mike Blair, Kansas Department of Wildlife and Parks.) Wetlands can be vegetated or nonvegetated and are classified on the basis of their hydrology, vegetation, and substrate. In this summary, wetlands are classified according to the system proposed by Cowardin and others (1979), which is used by the U.S. Fish and Wildlife Service (FWS) to map and inventory the Nation's wetlands. At the most general level of the classification system, wetlands are grouped into five ecological systems: Palustrine, Lacustrine, Riv- erine, Estuarine, and Marine. The Palustrine System includes only wetlands, whereas the other systems comprise wetlands and deepwater habitats. Wetlands of the systems that occur in Kansas are described below. System Palustrine Lacustrine Riverine. Wetland description Wetlands in which vegetation is predominantly trees (forested wetlands); shrubs (scrub-shrub wetlands); persistent or nonpersistent emergent, erect, rooted, herbaceous plants (persistent-and nonpersistent-emergent wetlands); or sub- mersed and (or) floating plants (aquatic beds). Also, intermittently to permanently flooded open-water bodies of less than 20 acres in which water is less than 6.6 feet deep. . Wetlands within an intermittently to permanently flooded lake or reservoir. Vegetation, when pres- ent, is predominantly nonpersistent emergent plants (nonpersistent-emergent wetlands), or submersed and (or) floating plants (aquatic beds), or both. . Wetlands within a channel. Vegetation, when pres- ent, is same as in the Lacustrine System. Palustrine wetlands in Kansas include ephemeral wetlands; marshes; emergent wetlands in ground-water seeps, prairies, and oxbows; and forested wetlands in riparian areas. Ephemeral wet- lands typically are flooded only seasonally; examples are sandhill pools located in the Arkansas River Valley in south-central Kansas and playa lakes scattered throughout the southwestern part of the State. Marshes occur in low-lying areas associated with river sys- tems, terraces, and valley basins. Examples of fresh marshes are the Marais des Cygnes Wildlife Area in east-central Kansas, Jamestown Wildlife Area in north-central Kansas, and Cheyenne Bottoms. Salt marshes generally are limited to central Kansas. The largest salt marsh in the State is Quivira National Wildlife Refuge, which is located along Rattlesnake Creek. Areas saturated by fresh ground- water seepage are discontinuously distributed throughout the State. An example of an emergent wetland in a ground-water seep is the 11-acre Muscotah Marsh in northeastern Kansas. Prairie wetlands occur on nearly level soils on flood plains along rivers, streams, and creeks throughout most of the State. The Ninnescah River Basin wetlands, associated with the North and South Forks Ninnescah Rivers in south-central Kansas, include examples of prairie wetlands as well as riparian woodlands. Forested wetlands are located within riparian woodlands and forests along major rivers in both the east- ern and western parts of the State (Lauver, 1989; Monda, 1992a). Lacustrine wetlands in Kansas are primarily in impoundments. The Flint Hills National Wildlife Refuge at John Redmond Reser- voir and Kirwin National Wildlife Refuge at Kirwin Reservoir are wetlands that have developed around lake headwater areas. These areas include both lacustrine wetlands and palustrine wetlands (per- sistent emergent, scrub-shrub, and forested wetlands along the shore or in backwater areas). Riverine wetlands are most common in the eastern and cen- tral parts of the State. They include the beds of shallow, intermit- tent streams and areas less than 6.6 feet deep in perennial streams. HYDROLOCIC SETTING The availability of water to sustain wetlands depends on cli- matic, hydrologic, and physiographic factors as well as historic and present land use. Moisture is unevenly distributed across the State. Average annual precipitation in Kansas ranges from less than 16 inches in the west to more than 40 inches in the southeast (Jordan, 1986). In contrast, average annual evaporation potential increases 196 National Water Summary Wetland Resources: STATE SUMMARIES from east to west, ranging from less than 44 inches in the northeast to more than 68 inches in the southwest (Farnsworth and others, 1982). Runoff is poorly sustained in the western and central parts of Kansas because of sparse precipitation, conservation practices, and withdrawals of water from streams and associated alluvial aqui- fers, primarily for irrigation. As a result, water deficits can occur during many seasons and years in these parts of the State. Differences in topography and geology separate Kansas into broad physiographic divisions (fig. 2B). In the Great Plains of west- ern Kansas, surface-water resources are scarce. Wetlands in these areas depend on water from precipitation and. in some areas, streamflow or shallow ground water. In the Central Lowland of eastern Kansas, surface water is more dependable. Water in streams, flood plains, and alluvial aquifers sustains many prairie wetlands and riparian woodlands and forests. In the O/.ark Plateaus, one of the wettest and most densely forested areas in Kansas, the abun- Great Central Lowland B PHYSIOGRAPHIC DIVISIONS Ozark Plateaus dant rainfall and high humidity create conditions favorable to wet- lands (Spanbauer, 1988). Wetlands in Kansas are temporarily, seasonally, semiperma- nently, or permanently flooded, depending on moisture availabil- ity. The playa lakes in southwestern Kansas are among the most temporary of palustrine wetlands, occurring in areas of low precipi- tation and high evaporation. Playas are sustained entirely by pre- cipitation and surface drainage. These shallow basins drain areas as large as 2,000 acres but are flooded only after heavy rainfall or snowmelt in the spring. The clay soils of the playas tend to prevent seepage losses; most water loss is due to evaporation. Sinks and shallow basins are other types of temporarily flooded wetlands in Kansas; they are mostly in the Great Plains region. The McPherson Valley Wetlands, a series of shallow lakes that histori- cally covered a 126-square-mile area south of McPherson, are sinks caused by dissolution of underlying salt formations. The McPherson Valley Wetlands originally included several large, and many small, shallow marshes and two natural lakes (Wilson, 1992). Only one permanently flooded lake remains, along with a few shallow pools and marshes that were not drained. These areas are important for migratory waterfowl. Ongoing restoration of the McPherson Val- ley Wetlands is intended to reestablish and protect the seasonally and permanently flooded pools (Wilson, 1992). Sandhill pools depressions between the low dunes along the Arkansas River northeast of Hutchinson become filled with wa- ter during the rainy season (Schoewe, 1949). Sandhill pools are poorly drained because of their nearly impervious subsoil. These wetlands can remain flooded, given a seasonally high water table, or can vanish during years of low precipitation (Lauver, 1989). Citv WETLANDS AND DEEPWATER HABITATS Distribution of wetlands and deepwater habitats This map shows the approximate distribution of large wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown ^^^1 Predominantly wetland Predominantly deepwater habitat Y^//^ Area typified by a high density of small wetlands 25 50 MILES 25 50 KILOMETERS Figure 2. Wetland distribution in Kansas and physiography of the State. A, Distribution of wetlands and deepwater habitats. B, Physio- graphy. (Sources: A, T.E. Dahl, U.S. Fish and Wildlife Service, unpub. data, 1991. B, Physiographic divisions from Fenneman, 1946; landforms data from EROS Data Center.) National Water Summary Wetland Resources: KANSAS 197 Wetlands associated with riparian woodlands and forests can be flooded temporarily or seasonally, depending on the character- istics of streams with which they are associated. Riparian forested wetlands are located primarily along the Missouri, Kansas, Marais des Cygnes, and Neosho Rivers in the Central Lowland, where pre- cipitation and runoff are sufficient to sustain streamflows and evapo- ration rates are relatively low. In prairie wetlands, drainage is poor, and the deep, alluvial soils remain saturated for most of the grow- ing season (Monda, 1992a). In some years, prairie wetlands along flood plains in eastern Kansas may be inundated for several days at a time (Lauver, 1989). Salt flats are seasonally inundated wetlands occurring on nearly level ground or within slight depressions. Salinity is high because of saline ground-water discharge or concentration of dis- solved constituents by evaporation. Salt flats are located in central Kansas, where naturally saline ground water discharges to surface streams and pools. Soils in salt flats are saturated but contain stand- ing water only after heavy precipitation (Monda, 1992a). Fresh and salt marshes form in low-lying areas that have deep, poorly drained soils. Marshes range from semipermanently to per- manently flooded (Monda, 1992a). Salt marshes are restricted to salty seepage areas that often contain brackish or stagnant water (Lauver, 1989). Quivira National Wildlife Refuge is sustained by water from Rattlesnake Creek. …