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Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and with other agencies U.S. Department of the Interior U.S. Geological Survey Water Resources Data Puerto Rico and the U.S. Virgin Islands Water Year 2000 PUERTO RICO U.S. VIRGIN ISLANDS Culebra Island St. John Island St. Thomas Island St. Croix Island Vieques Island Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and with other agencies U.S. Department of the Interior U.S. Geological Survey Water Resources Data Puerto Rico and the U.S. Virgin Islands Water Year 2000 PUERTO RICO U.S. VIRGIN ISLANDS Culebra Island St. John Island St. Thomas Island St. Croix Island Vieques Island By Pedro L. Díaz, Zaida Aquino, Carlos Figueroa-Alamo, Ricardo J. Vachier, and Ana V. Sánchez Water-Data Report PR-00-1 U.S. DEPARTMENT OF THE INTERIOR GALE  A.  NORTON, Secretary U.S. GEOLOGICAL SURVEY Charles G. Groat, Director For additional information on the water resources investigation programs in Puerto Rico and the U.S. Virgin Islands write to: Chief, Caribbean District, Water Resources Division U.S. Geological Survey GSA Center, 651 Federal Drive Suite 400-15 Guaynabo, Puerto Rico  00965 Telephone:  (787) 749-4346 2001 III   PREFACE This annual hydrologic data report of Puerto Rico and the U.S. Virgin Islands is one of a series of annual reports that document hydrologic data gathered from the U.S. Geological Survey's surface- and ground-water data-collection networks in each state, Puerto Rico, the U.S. Virgin Islands, and the other Trust Territories. These records of streamflow, ground-water levels, and quality  of  water  provide  the  hydrologic  information  needed  by  state,  local,  and  Federal  agencies,  and  the  private  sector  for developing and managing our Nation's land and water resources. The report is the culmination of a concerted effort by dedicated personnel of the U.S. Geological Survey, Water Resources Division, who collected, compiled, analyzed, verified, and organized the data, and who typed, edited, and assembled the report. In addition to the authors, who had primary responsibility for assuring that the information contained herein is accurate, complete, and adheres to the U.S. Geological Survey policy and established guidelines, the following personnel contributed significantly to the collection, processing and tabulations of the data:                                                                                                       JosÈ M. Agis Victoria NuÒez George Arroyo Nilo PeÒa RamÚn Carraquillo Rafael PeÒa-CortÈz Gregory Cherry Ronald T. Richards Iris M. ConcepciÛn Carlos C. RodrÌguez JosÈ A. ConcepciÛn  Julio A. RodrÌguez Israel Cruz Miguel A. RodrÌguez Teresa Dopazo Rafael M. RodrÌguez Angel G. Ferrer Manuel Rosario Robert Fitzhugh JosÈ RenÈ S· nchez Wilfredo GarcÌa Luis Santiago-Rivera Hector Guardiola Carlos Santos Evelyn S. Guevara Luis Soler SenÈn Guzm· n-RÌos Elliot M. Sosa Felipe Hern· ndez Angel Torres Sandra Lagares James Torres Christian D. LÛpez Ahmed Valencia JosÈ Merced Luis Vega Carlos Narvaez Michael Walsh                                                  Francisco Maldonado prepared the illustrations and Evelyn S. Guevara typed the text of the report and was mainly responsible for the assemble of the book using Automated Annual Report (AAR) Scripts for Surface Water Discharge and Water Quality Stations.                                              This report was prepared in cooperation with agencies of the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and with other federal agencies under the general supervision of Mathew C. Larsen, District Chief, Caribbean District, San Juan, Puerto Rico. REPORT DOCUMENTATION PAGE Form Approved OMB No.  0704-0188 4.  TITLE AND SUBTITLE 5.  FUNDING  NUMBERS 6.  AUTHOR(S) 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING  ORGANIZATION REPORT NUMBER 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. AGENCY REPORT NUMBER 11.  SUPPLEMENTARY NOTES 12a. DISTRIBUTION / AVAILABILITY  STATEMENT 12b.  DISTRIBUTION CODE 13.  ABSTRACT (Maximum 200 words) 14.  SUBJECT TERMS 15.  NUMBER OF PAGES 16.  PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT 18.  SECURITY CLASSIFICATION OF THIS PAGE 19.  SECURITY CLASSIFICATION OF ABSTRACT 20.  LIMITATION OF ABSTRACT 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED SPONSORING / MONITORING Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources,  gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this  collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson  Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503. May 16, 2001. Annual - October 1, 1999 to September 30, 2000 Water Resources Data for Puerto Rico and the U.S. Virgin Islands Water Year 2000 Pedro L. DÌaz, Zaida Aquino, Carlos Figueroa-Alamo, Ricardo J. Vachier, Ana V. S· nchez U.S. Geological Survey, Water Resources Division GSA Center, 651 Federal Drive, Suite 400-15 Guaynabo, Puerto Rico  00965 USGS-WDR-PR-00-1 U.S. Geological Survey, Water Resources Division GSA Center, 651 Federal Drive, Suite 400-15 Guaynabo, Puerto Rico  00965 USGS-WDR-PR-00-1 Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and other agencies. NO RESTRICTION ON DISTRIBUTIONS Water resources data for surface-water, quality-of-water, and ground-water records for the 2000  water year for Puerto Rico and the U.S. Virgin Islands consists of records of discharge, water quality of streams, and water levels of wells.  This report contains discharge records for 85 streamflow-gaging stations; daily sediment records for 26 streamflow stations; 21 partial record or miscellaneous streamflow stations; stage records for 18 reservoirs; water-quality records for 16 streamflow-gaging stations, 42 ungaged streamsites, 11 lake sites, 2 lagoons, and 1 bay; and water-level records for 108 observation wells.  These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating local and federal agencies in Puerto Rico and the U.S. Virgin Islands. *Surface water, *Water quality, *Ground water, Aquifers, Chemical analysis, Gaging stations, Hydrologic data sediments, Streamflow, Water analysis, Water levels, Lakes 696 Unclassified Unclassified V CONTENTS Page Preface........................................................................................................................................................................................ iii List of surface-water and water-quality stations, in downstream order, for which records are published in this volume....................................................................................................... vii List of ground-water wells, by basin, for which records are published in this volume..................................................................................................................................................... xi List of discontinued surface-water discharge or stage-only stations ....................................................................................... xiv Introduction..................................................................................................................................................................................1 Cooperation..................................................................................................................................................................................2 Summary of hydrologic conditions..............................................................................................................................................3 Rainfall ..................................................................................................................................................................................3 Surface water.........................................................................................................................................................................3 Ground water.........................................................................................................................................................................5 Water quality .........................................................................................................................................................................9 Special networks and programs .................................................................................................................................................10 Explanation of records...............................................................................................................................................................10 Station identification numbers.............................................................................................................................................11 Downstream order system.............................................................................................................................................11 Latitude-longitude system.............................................................................................................................................11 Records of stage and water discharge .................................................................................................................................19 Data collection and computation...................................................................................................................................19 Data Presentation ..........................................................................................................................................................20 Station manuscript ..................................................................................................................................................20 Data table of daily mean values..............................................................................................................................21 Statistics of monthly mean data..............................................................................................................................22 Summary statistics..................................................................................................................................................22 Identifying estimated daily discharge ...........................................................................................................................23 Accuracy of the records ................................................................................................................................................23 Records of surface-water quality.........................................................................................................................................24 Classification of records................................................................................................................................................24 Arrangement of records ................................................................................................................................................24 On-site measurements and sample collection ...............................................................................................................24 Water temperature......................................................................................................................................................................25 Sediment........................................................................................................................................................................25 Laboratory measurements.............................................................................................................................................25 Data presentation...........................................................................................................................................................26 Remark codes................................................................................................................................................................27 Records of ground-water levels...........................................................................................................................................27 Data collection and computation...................................................................................................................................27 Data presentation...........................................................................................................................................................28 Records of ground-water quality.........................................................................................................................................28 Data collection and computation...................................................................................................................................29 Data presentation...........................................................................................................................................................29 Access to U.S. Geological Survey Water Data..........................................................................................................................29 Definition of terms.....................................................................................................................................................................30 Publications on Techniques of Water-Resources Investigations...............................................................................................42 Surface- and quality-of-water records for Puerto Rico..............................................................................................................47 Water-quality at partial-record stations in Puerto Rico and U.S. Virgin Islands.....................................................................511 Ground-water records for Puerto Rico.....................................................................................................................................525 Surface-water records for U.S. Virgin Islands.........................................................................................................................655 Ground-water records for U.S. Virgin Islands ........................................................................................................................665 Index ........................................................................................................................................................................................673 VI ILLUSTRATIONS Page Figure 1. Graphs showing monthly-mean discharge of selected streams in Puerto Rico .......................................................4 2. Graphs showing ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands.......................8 3. Map showing location of maximum concentration of fecal coliform bacteria at the water-quality sampling sites in Puerto Rico ......................................................................................................12 4. Map showing location of maximum concentration of fecal streptococci bacteria at the water-quality sampling sites in Puerto Rico ......................................................................................................13 5. Map showing location of surface-water stations in Puerto Rico ...........................................................................14 6. Map showing location of water-quality stations in Puerto Rico............................................................................15 7. Map showing location of ground-water stations in Puerto Rico............................................................................16 8. Map showing location of surface-water stations in the U.S. Virgin Islands..........................................................17 9. Map showing location of ground-water stations in the U.S. Virgin Islands..........................................................18 10. Grid showing system for numbering wells and miscellaneous sites (latitude and longitude)..............................19 11. Map showing the Río Guajataca basin..................................................................................................................49 12. Map showing the Río Camuy basin......................................................................................................................61 13. Map showing the Río Grande de Arecibo basin ...................................................................................................65 14. Map showing the Río Grande de Manatí basin...................................................................................................129 15. Map showing the Río Cibuco basin....................................................................................................................155 16. Map showing the Río de la Plata basin...............................................................................................................165 17. Map showing the Río Hondo to Río Puerto Nuevo basins.................................................................................191 18. Map showing the Río Grande de Loíza basin.....................................................................................................229 19. Map showing northeastern river basins -- Río Herrera to Río Antón Ruíz basins .............................................343 20. Map showing southeastern river basins -- Río Humacao to Quebrada Aguas Verdes .......................................381 21. Map showing south coast river basins -- Río Salinas to Río Jacaguas basins ....................................................405 22. Map showing south coast river basins -- Río Inabón to Río Loco basins...........................................................427 23. Map showing the Río Guanajibo basin...............................................................................................................461 24. Map showing the Río Yagüez and Río Grande de Añasco basins......................................................................477 25. Map showing the Río Culebrinas basin ..............................................................................................................493 26. Map showing location of low-flow partial-record stations in Mayagüez, Puerto Rico.....................................505 TABLES Page Table 1. Island-wide monthly rainfall for the water year 2000 and annual averages for the 30-year reference period, 1961-90........................................................................................................................3 2. Highest ground-water level recorded during water year 2000 and previous highest ground-water levels at selected wells in Puerto Rico ...........................................................................................6 3. Lowest ground-water levels recorded during water year 2000 and previous lowest ground-water levels at selected wells in Puerto Rico ...........................................................................................7 4. Surface-water quality stations in Puerto Rico with highest concentration of selected constituents during water year 2000 .....................................................................................................................9 VII SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME  (Letter after station name designates type of data: (d) discharge, (c) chemical, (b) biological, (s) sediment, (p) pesticide, (e) elevation, gage heights)     Station number          Page RIO GUAJATACA BASIN RÌo Guajataca at Lares (d,c,b) ...................................................................................................... 50010500 50 Lago Guajataca at Damsite near Quebradillas (e) ........................................................................ 50010800 54 Canal Principal de Diversiones at Lago Guajataca (c,b) .............................................................. 50011000 56 RÌo Guajataca above mouth near Quebradillas (c,b) .................................................................... 50011400 58 RIO CAMUY BASIN RÌo Camuy near Bayaney (d)........................................................................................................ 50014800 62 RIO GRANDE DE ARECIBO BASIN Lago Garzas near Adjuntas (e) ............................................................................................. 50020100 66 RÌo Grande de Arecibo near Adjuntas (d,c,b) .............................................................................. 50020500 68 RÌo Pellejas above Central Pellejas (d)......................................................................................... 50021030 72 RÌo Grande de Arecibo above Utuado (d) .................................................................................... 50021700 74 RÌo Grande de Arecibo below Utuado (d,s) ................................................................................. 50024950 78           RÌo Grande de Arecibo near Utuado (c,b) ................................................................................... 50025000 86 RÌo Saliente at Coabey near Jauyuya (d)...................................................................................... 50025155 88 RÌo Jauca at Paso Palma (d).......................................................................................................... 50025850 92 RÌo Caonillas at Paso Palma (d,s)................................................................................................. 50026025 94 RÌo Caonillas above Lago Caonillas near Jayuya (c,b) ................................................................ 50026050 99 Lago Caonillas at Damsite near Utuado (e).......................................................................... 50026140 100 RÌo Yunes at Hwy. 140 near Florida (d)....................................................................................... 50026400 102 RÌo LimÛn above Lago Dos Bocas (d) ......................................................................................... 50027000 104 Lago Dos Bocas at Damsite near Utuado (e)........................................................................ 50027100 106 RÌo Grande de Arecibo below Lago Dos Bocas near Florida (c,b) .............................................. 50027250 108 RÌo Grande de Arecibo above Arecibo (d,s)................................................................................. 50027750 110 RÌo Tanam·  near Utuado (d,c,b,s)........................................................................................ 50028000 115 RÌo Tanam·  at Charco Hondo (d) ........................................................................................ 50028400 122 RÌo Grande de Arecibo at Central Cambalache (d,c,b) ................................................................ 50029000 124 RIO GRANDE DE MANATI BASIN RÌo Orocovis at Orocovis (d)................................................................................................ 50030460 130 RÌo Orocovis near Orocovis (c,b)......................................................................................... 50030700 132 RÌo Grande de ManatÌ near Morovis (d,c,b)................................................................................. 50031200 134 Lago El Guineo at Damsite near Villalba (e) ....................................................................... 50032290 138 Lago de Matrullas at Damsite near Orocovis (e).................................................................. 50032590 140 RÌo Bauta near Orocovis (d)................................................................................................. 50034000 142 RÌo Grande de ManatÌ at Ciales (d) .............................................................................................. 50035000 144 RÌo Grande de ManatÌ at Highway 149 at Ciales (c,b)................................................................. 50035500 146 RÌo Cialitos at Highway 649 at Ciales (c,b) ......................................................................... 50035950 148 RÌo Grande de ManatÌ at Highway 2 near ManatÌ (d,c,b,p).......................................................... 50038100 150 LAGUNA TORTUGUERO BASIN Laguna Tortuguero Outlet near Vega Baja (c,b) .......................................................................... 50038200 154 RIO CIBUCO BASIN RÌo Cibuco below Corozal (d,c,b) ................................................................................................ 50038320 158 RÌo Cibuco at Vega Baja (d,c,b)................................................................................................... 50039500 162 RIO DE LA PLATA BASIN Lago Carite at Gate Tower near Cayey (e)................................................................................... 50039990 168 RÌo de la Plata at Proyecto La Plata (c,b) ..................................................................................... 50043000 170 RÌo de la Plata at Comerio (d,s).................................................................................................... 50043800 172 RÌo de la Plata near Comerio (c,b)................................................................................................ 50044000 178 RÌo Guadiana near Naranjito (c,b)........................................................................................ 50044850 180 Lago La Plata at Damsite near Toa Alta (e) ................................................................................. 50045000 181 RÌo de la Plata below La Plata Dam (d,s)..................................................................................... 50045010 183 RÌo de la Plata at Highway 2 near Toa Alta (d,c,b,s,p) ................................................................ 50046000 189 RIO HONDO BASIN VIII SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME--Continued     Station number          Page RIO DE BAYAMON BASIN RÌo de BayamÛn at Arenas (d)...................................................................................................... 50047535 196 RÌo Sabana at Vista Monte (d).............................................................................................. 50047540 198 Lago de Cidra at Damsite near Cidra (e) ...................................................................................... 50047550 200 RÌo de BayamÛn below Cidra Damsite (d,s) ................................................................................ 50047560 202 RÌo de BayamÛn near Aguas Buenas (c,b) ................................................................................... 50047600 208 RÌo de BayamÛn near BayamÛn (d).............................................................................................. 50047850 210 RÌo Guaynabo near BayamÛn (c,b)....................................................................................... 50047990 212 RÌo de BayamÛn at Flood Channel at BayamÛn (c,b,p) ............................................................... 50048510 214 RIO PUERTO NUEVO BASIN RÌo Piedras: Lago Las CurÌas at Damsite near RÌo Piedras (e)......................................................................... 50048680 216         Quebrada Las CurÌas below Las CurÌas Damsite (d).................................................................... 50048690 218 RÌo Piedras at El SeÒorial(d) ........................................................................................................ 50048770 220 RÌo Piedras near RÌo Piedras (c,b,p)............................................................................................. 50048800 222 RÌo Piedras at Hato Rey (d,c,b) .................................................................................................... 50049100 224 Laguna San JosÈ: Laguna San JosÈ No. 2 at San Juan (c,b)...................................................................................... 50049820 228 BahÌa de San Juan: BahÌa de San Juan No. 5 at San Juan (c,b) ................................................................................... 50049920 229 QUEBRADA BLASINA BASIN Quebrada Blasina near Carolina (c,b)........................................................................................... 50050300 232 RIO GRANDE DE LOIZA BASIN RÌo Grande de LoÌza at Quebrada Arenas (d)............................................................................... 50050900 234 Quebrada Blanca at El Jagual (d,s)....................................................................................... 50051150 236 Quebrada Salvatierra near San Lorenzo (d,s) ....................................................................... 50051180 242 RÌo Cayagu· s at Cerro Gordo (d) ......................................................................................... 50051310 248 RÌo Grande de LoÌza at Highway 183 near San Lorenzo (d,s)..................................................... 50051800 250 RÌo Turabo above Borinquen (d,s) ....................................................................................... 50053025 256 RÌo Grande de LoÌza at Caguas (d,c,b,s) ...................................................................................... 50055000 262 RÌo Cag¸ itas:                                                                                                                                                        RÌo Cag¸ itas near Aguas Buenas (d,s).................................................................................. 50055100 269 RÌo Cag¸ itas at Villa Blanca at Caguas (d,s)........................................................................ 50055225 275 RÌo Cag¸ itas at Highway 30 at Caguas (c,b)........................................................................ 50055250 281 RÌo Bairoa:                                                                                                                                                      RÌo Bairoa at Bairoa (d,s) ..................................................................................................... 50055390 283 RÌo Bairoa near Caguas (c,b)................................................................................................ 50055400 291 RÌo Gurabo: RÌo Gurabo below El MangÛ (d,s)........................................................................................ 50055750 293      RÌo Valenciano near Juncos (d,s) .................................................................................... 50056400 299 RÌo Gurabo at Gurabo (d,s)................................................................................................... 50057000 305 RÌo Gurabo near Gurabo (c,b) .............................................................................................. 50057025 311 RÌo CaÒas at RÌo CaÒas (d,s) ................................................................................................ 50058350 313 Lago LoÌza at Damsite near Trujillo Alto (c,b,e) ......................................................................... 50059000 319 RÌo Grande de LoÌza below Damsite (d,s).................................................................................... 50059050 322 RÌo Grande de LoÌza below Trujillo Alto (c,b) ............................................................................ 50059100 328 RÌo CanÛvanas near Campo Rico (d,s)......................................................................................... 50061800 330 RIO ESPIRITU SANTO BASIN Quebrada Sonadora near El Verde(d)................................................................................... 50063440 346 RÌo EspÌritu Santo near RÌo Grande (d,c,b).................................................................................. 50063800 348 RÌo Grande near El Verde (d)............................................................................................... 50064200 351 RIO MAMEYES BASIN RÌo Mameyes near Sabana (d,s) ................................................................................................... 50065500 353 RÌo Mameyes at Mameyes (d)...................................................................................................... 50066000 359 IX SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME--Continued     Station number          Page RIO SABANA BASIN RÌo Sabana at Sabana (d).............................................................................................................. 50067000 361 RIO FAJARDO BASIN RÌo Fajardo above Fajardo (d,s) ................................................................................................... 50070500 363 RÌo Fajardo near Fajardo (d,c,b,p,s) ............................................................................................. 50071000 369 RÌo Fajardo below Fajardo (c,b)................................................................................................... 50072500 377 RIO BLANCO BASIN Quebrada Guab·  near Naguabo (d) .............................................................................................. 50074950 379 RÌo Icacos near Naguabo (d) ........................................................................................................ 50075000 381 RIO HUMACAO BASIN RÌo Humacao at Las Piedras (d) ................................................................................................... 50081000 384 RÌo Humacao at Highway 3 at Humacao (c,b)............................................................................. 50082000 386 RIO GUAYANES BASIN RÌo GuayanÈs at Yabucoa (c,b,p) ................................................................................................. 50083500 388 RÌo GuayanÈs above mouth at Playa de GuayanÈs (c,b) .............................................................. 50086500 390 RIO MAUNABO BASIN RÌo Maunabo at Lizas (d) ............................................................................................................. 50090500 392 RÌo Maunabo at Maunabo (c,b) .................................................................................................... 50091000 394 RIO CHICO BASIN RÌo Chico at Providencia (c,b)...................................................................................................... 50091800 396 RIO GRANDE DE PATILLAS BASIN RÌo Grande de Patillas near Patillas (d,c,b) .................................................................................. 50092000 398 RÌo MarÌn near Patillas (d)............................................................................................................ 50093000 402 Lago Patillas at Damsite near Patillas (e)..................................................................................... 50093045 404 RIO SALINAS BASIN RÌo Lapa near Rabo del Buey (d) ................................................................................................. 50100200 408 RÌo Majada at La Plena (d)........................................................................................................... 50100450 410 RIO COAMO BASIN RÌo Coamo at Coamo (d).............................................................................................................. 50106100 412 RÌo Coamo near Coamo (c,b) ....................................................................................................... 50106500 414 RIO DESCALABRADO BASIN RÌo Descalabrado near Los Llanos (d) ......................................................................................... 50108000 415 RIO JACAGUAS BASIN RÌo Toa Vaca above Lago Toa Vaca (d,s)............................................................................ 50110900 417 Lago Toa Vaca at Damsite near Villaba (e) ................................................................................. 50111210 423 Lago Guayabal at Damsite near Juana DÌaz (e)............................................................................ 50111300 425 RÌo Jacaguas at Juana DÌaz (d) ..................................................................................................... 50111500 427 RIO INABON BASIN RÌo InabÛn at Real Abajo (d)........................................................................................................ 50112500 430 RIO BUCANA BASIN RÌo Cerrillos above Lago Cerrillos near Ponce (d)....................................................................... 50113800 432 Lago Cerrillos at Damsite near Ponce (e)..................................................................................... 50113950 434 RÌo Cerrillos near Ponce (d,c,b).................................................................................................... 50114000 436 RÌo Bucan·  at Highway 14 Bridge near Ponce (d)....................................................................... 50114390 440 X SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME--Continued     Station number          Page RIO PORTUGUES BASIN RÌo PortuguÈs at Tibes (d,s).......................................................................................................... 50114900 442 RÌo PortuguÈs near Ponce (c,b)................................................................................................... ..50115000 448 RÌo PotuguÈs at Highway 14 near Ponce (d)................................................................................ 50115900 449 RÌo PortuguÈs at Ponce (c,b,p)...................................................................................................... 50116200 451 RIO GUAYANILLA BASIN RÌo Guayanilla near Guayanilla (d).............................................................................................. 50124200 453 RÌo Guayanilla at Central Rufina (c,b,p) ...................................................................................... 50124700 455 RIO YAUCO BASIN Lago Lucchetti at Damsite near Yauco (e) ................................................................................... 50125780 457 RIO LOCO BASIN Lago Loco at Damsite near Yauco (e).......................................................................................... 50128900 459 RÌo Loco at Gu· nica (c,b,p).......................................................................................................... 50129700 461 RIO GUANAJIBO BASIN RÌo Guanajibo at Highway 119 at San Germ· n (d)...................................................................... 50131990 464 RÌo Guanajibo near San Germ· n (c,b).......................................................................................... 50133600 466 RÌo Rosario near Hormigueros (d,c,b,s) ............................................................................... 50136400 468 RÌo Guanajibo near Hormigueros (d,c,b,p)................................................................................... 50138000 475 RIO YAGUEZ BASIN RÌo Yag¸ ez near Mayag¸ ez (c,b) ................................................................................................. 50138800 480 RIO GRANDE DE A—ASCO BASIN Lago Guayo at Damsite near CastaÒer (e)............................................................................ 50141500 482 RÌo Grande de AÒasco near Lares (c,b)........................................................................................ 50143000 484 RÌo Grande de AÒasco near San Sebasti· n (d,c,b) ....................................................................... 50144000 486 RÌo Grande de AÒasco near AÒasco (c,b,p).................................................................................. 50146000 492 RIO CULEBRINAS BASIN RÌo Culebrinas near San Sebasti· n (c,b)....................................................................................... 50147600 496 RÌo Culebrinas at Highway 404 near Moca (d) ............................................................................ 50147800 498 RÌo Culebrinas at Margarita Dam near Aguada (d)...................................................................... 50148890 500 RÌo Culebrinas near Aguada (c,b,p).............................................................................................. 50149100 502 Analyses of samples collected of water-quality partial-record stations and miscellaneous sites.................................................................................................................... 513 ST. THOMAS, U.S. VIRGIN ISLANDS Bonne Resolution Gut at Bonne Resolution (d) ........................................................................... 50252000 660 Turpentine Run at Mount Zion (d) ............................................................................................... 50274000 662 ST. JOHN, U.S. VIRGIN ISLANDS Guinea Gut at Bethany (d)............................................................................................................ 50295000 664 ST. CROIX, U.S. VIRGIN ISLANDS Jolly Hill Gut at Jolly Hill (d)....................................................................................................... 50345000 666 XI GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED Page RIO GUAJATACA BASIN       Well 182925067031100 Local number 1001 .......................................................................................................................................530       Well 182422067015100 Local number  165 ........................................................................................................................................532       Well 182647066552400 Local number  202 ........................................................................................................................................533 RIO CAMUY BASIN       Well 182723066511200 Local number 1026 .......................................................................................................................................534       Well 182431066463400 Local number 1027 .......................................................................................................................................535 RIO GRANDE DE ARECIBO BASIN       Well 182756066454700 Local number 1051 .......................................................................................................................................536       Well 182737066370900 Local number  204 ........................................................................................................................................537       Well 182616066364100 Local number 1052 .......................................................................................................................................538       Well 182626066345100 Local number 1053 .......................................................................................................................................539       Well 182603066333601 Local number 1054 .......................................................................................................................................540       Well 182642066394900 Local number 1055 .......................................................................................................................................542       Well 182639066385200 Local number 1056 .......................................................................................................................................543       Well 182209066340600 Local number 1057 .......................................................................................................................................544 RIO GRANDE DE MANATI BASIN       Well 182544066341500 Local number  205 ........................................................................................................................................545       Well 182757066325600 Local number  206 ........................................................................................................................................546       Well 182710066303700 Local number  207 ........................................................................................................................................547       Well 182549066304300 Local number  166 ........................................................................................................................................548       Well 182506066280200 Local number 1076 .......................................................................................................................................549       Well 182308066260400 Local number  210 ........................................................................................................................................550   RIO CIBUCO BASIN       Well 182614066261500 Local number 1101 .......................................................................................................................................551       Well 182712066251700 Local number 1102 .......................................................................................................................................552       Well 182615066235300 Local number  211 ........................................................................................................................................553       Well 182647066201700 Local number   70 .........................................................................................................................................554       Well 182515066194000 Local number  212 ........................................................................................................................................555       Well 182330066185700 Local number  213 ........................................................................................................................................556       Well 182426066260400 Local number 1103 .......................................................................................................................................557 RIO DE LA PLATA BASIN       Well 182526066165001 Local number 1127 .......................................................................................................................................558       Well 182548066164401 Local number 1128 .......................................................................................................................................560       Well 182620066163400 Local number 1129 .......................................................................................................................................561       Well 182620066163403 Local number 1130 .......................................................................................................................................563       Well 182657066162700 Local number 1131 .......................................................................................................................................564       Well 182657066162701 Local number 1132 .......................................................................................................................................565       Well 182654066150600 Local number 1133 .......................................................................................................................................566       Well 182530066135400 Local number  216 ........................................................................................................................................567 XII GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED Page  RIO DE LA PLATA BASIN--Continued      Well 182655066142400 Local number  217 .........................................................................................................................................568       Well 180649066095500 Local number 1134 .......................................................................................................................................569 RIO HONDO TO RIO PUERTO NUEVO BASINS       Well 182441066082600 Local number  219 ........................................................................................................................................570       Well 182531066075900 Local number  652 ........................................................................................................................................571       Well 182511066045401 Local number 1152 .......................................................................................................................................572       Well 182435066052700 Local number 1153 .......................................................................................................................................573       Well 182445066043401 Local number 1154 .......................................................................................................................................574       Well 182443066041502 Local number 1155 .......................................................................................................................................575       Well 182417066042700 Local number 1156 .......................................................................................................................................576       Well 182349066032600 Local number 1157 .......................................................................................................................................577       Well 182406066034700 Local number 1158 .......................................................................................................................................578       Well 182451066080200 Local number 1159 .......................................................................................................................................579 RIO GRANDE DE LOIZA BASIN       Well 181352066025300 Local number 1176 .......................................................................................................................................580       Well 181311066022500 Local number 1177 .......................................................................................................................................581       Well 181446066013400 Local number 1178 .......................................................................................................................................582       Well 181539066014500 Local number 1179 .......................................................................................................................................583       Well 181550065593200 Local number   50 .........................................................................................................................................584       Well 182515065594100 Local number  222 ........................................................................................................................................585       Well 181540065580300 Local number 1180 .......................................................................................................................................587       Well 181513065554600 Local number 1181 .......................................................................................................................................588 RIO HERRERA TO RIO ANTON RUIZ BASINS       Well 182344065490801 Local number 1201 .......................................................................................................................................589       Well 182223065455900 Local number 1202 .......................................................................................................................................590       Well 181230065444900 Local number 1203 .......................................................................................................................................591       Well 182138065431800 Local number 1204 .......................................................................................................................................592       Well 182131065421100 Local number 1205 .......................................................................................................................................593       Well 181917065382701 Local number 1207 .......................................................................................................................................594       Well 182234065440000 Local number 1208 .......................................................................................................................................595 RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS       Well 180358065503600 Local number 1226 .......................................................................................................................................597       Well 180415065513900 Local number   96 .........................................................................................................................................598       Well 175855066023100 Local number 1227 .......................................................................................................................................599       Well 175855066050500 Local number 1228 .......................................................................................................................................600       Well 175728066072200 Local number 1229 .......................................................................................................................................601       Well 175719066085500 Local number 1230 .......................................................................................................................................602       Well 175858066100200 Local number    6 ..........................................................................................................................................603       Well 180002066132200 Local number 1231 .......................................................................................................................................604       Well 180001066122002 Local number 1232 .......................................................................................................................................606       Well 175947066130601 Local number 1233 .......................................................................................................................................608       Well 175957066123400 Local number 1234 .......................................................................................................................................610 XIII GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED                                                                                                                                                                                                                                                Page RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS--Continued      Well 180027065541700 Local number 1235 ........................................................................................................................................612       Well 180018066010100 Local number 1236 .......................................................................................................................................613       Well 175903066024100 local number 1237.........................................................................................................................................614       Well 175841066104500 Local number 1238 .......................................................................................................................................615       Well 175814066102200 Local number 1239 .......................................................................................................................................616 RIO SALINAS TO RIO JACAGUAS BASINS       Well 175809066133100 Local number 1251 .......................................................................................................................................617       Well 180206066135500 Local number 1252 .......................................................................................................................................618       Well 180104066152300 Local number 1253 .......................................................................................................................................619       Well 175910066155500 Local number 1254 .......................................................................................................................................620       Well 175903066165000 Local number 1256 .......................................................................................................................................621      Well 175943066224800 Local number 1257 ........................................................................................................................................623       Well 175829066232200 Local number   87 .........................................................................................................................................624       Well 180020066261500 Local number 1258 .......................................................................................................................................625       Well 180602066133100 Local number 1260 .......................................................................................................................................626       Well 175833066145800 Local number 1261 .......................................................................................................................................627       Well 175735066151800 Local number 1262 .......................................................................................................................................635 RIO INABON TO RIO LOCO BASINS       Well 175950066354200 Local number  141 ........................................................................................................................................645       Well 175934066364800 Local number 1276 .......................................................................................................................................646       Well 180045066381600 Local number 1277 .......................................................................................................................................647       Well 180156066434000 Local number 1278 .......................................................................................................................................648       Well 180133066503300 Local number  132 ........................................................................................................................................649       Well 175840066494400 Local number 1279 .......................................................................................................................................650 RIO GUANAJIBO BASIN       Well 180132067033800 Local number  143 ........................................................................................................................................651       Well 180542067084000 Local number 1301 .......................................................................................................................................652       Well 180628067084300 Local number 1302 .......................................................................................................................................653       Well 180628067084301 Local number 1303 .......................................................................................................................................654       Well 180802067073300 Local number 1304 .......................................................................................................................................655 RIO YAG‹ EZ TO RIO GRANDE DE A—ASCO BASINS       Well 181232067083700 Local number 1326 .......................................................................................................................................656 RIO CULEBRINAS BASIN       Well 182017067143300 Local number 1352 .......................................................................................................................................657       Well 182442067091700 Local number  200 ........................................................................................................................................658 ST. CROIX, U.S. VIRGIN ISLANDS       Well 174225064472000 Local number 2 .............................................................................................................................................670       Well 174243064475100 Local number 3 .............................................................................................................................................671       Well 174316064480800 Local number 13 ...........................................................................................................................................672 ST. THOMAS, U.S. VIRGIN ISLANDS       Well 182038064550300 Local number 6 .............................................................................................................................................673       Well 182038064580000 Local number 8 .............................................................................................................................................674 ST. JOHN, U.S. VIRGIN ISLANDS Well 181956064464500 Local number 11 675 XIV WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 DISCONTINUED  STREAMFLOW STATIONS  The following continuous-record streamflow stations in Puerto Rico and the U.S. Virgin Islands have been discontinued or converted to partial-record stations.  Daily streamflow or stage records were collected for the period of record shown for each station. Station Station name Drainage Period of number  area (mi2) record   50007000 Quebrada de los Cedros near Isabela 6.91  1970 50010600 RÌo Guajataca above Lago de Guajataca --  1984-89 50011000 Canal Diversion Lago Guajataca -- 1970 50011200 RÌo Guajataca below Lago Guajataca      --  1969-70,1984-87 50011400 RÌo Guajataca above mouth near Quebradillas  --  1969-70,1984-89 50013000 RÌo Camuy near Lares         7.62 1969-71 50014000 RÌo Criminales near Lares    4.68  1969-70 50014600 RÌo Camuy at Tres Pueblos Sinkhole -- 1990-96 50015700 RÌo Camuy near Hatillo -- 1984-96 50016000 RÌo Camuy near Camuy                    --  1969-73 50021050 RÌo Pellejas below Central Pellejas  7.89 1972-75 50021500 RÌo Pellejas near Utuado   9.55  1969-71 50023000 RÌo VivÌ near Central Pellejas   5.66   1969-75 50027200 RÌo Grande de Arecibo blw. Lago dos Bocas   169  1970-71 50031500 RÌo Sana Muerto near Orocovis  3.68 1965-70 50035200 RÌo Grande de ManatÌ at Hwy 145 at Ciales 132  1972 50035950 RÌo Cialitos at Hwy 649 at Ciales  17  1970-82 50038360 RÌo Mavilla near Corozal 9.51  1969-70 50038600 RÌo UnibÛn near Morovis   5.29 1969-70 50038700 RÌo Morovis at Morovis  1.26 1968 50038900 RÌo Indio at Vega Baja    --  1963,66,71 50039600 RÌo Cibuco at Central San Vicente  --  1969-72 50043200 RÌo Usabon near Barranquitas      9.15  1968-69,71 50043400 RÌo Aibonito Tributary near Aibonito 1.13 1968-71 50044600 RÌo Guadiana near Naranjito 1.73  1971 50044650 Quebrada del Toro near Naranjito  0.54 1971 50044800 Quebrada Anones near Naranjito 2.32 1971 50045700 RÌo Lajas at Toa Alta    8.65 1966-75 50047820 RÌo de BayamÛn at Hwy 174 near BayamÛn 31.90  1966 50048000 RÌo de BayamÛn at BayamÛn 71.90  1963-67 50049000  RÌo Piedras at RÌo Piedras 12.5 1971-82, 1987-93 50049310 Quebrada Josefina at PiÒero Avenue 3.84  1988-91 50053050  RÌo Turabo at Borinquen     7.89 1984-90 50054000 Quebrada de las Quebradillas near Caguas 6.25 1969-71,73 50055170 RÌo Cag¸ itas near Caguas 8.27 1992-97 50055650   Quebrada Caimito near Juncos   0.82  1984-87 50056000   RÌo Valenciano near Las Piedras 6.85 1971 50056900 Quebrada Mamey near Gurabo  2.30 1984-92 50058300 Quebrada Arena near Caguas --  1971 50061300 RÌo Canovanillas near LoÌza 14.40  1968-73 XV WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 DISCONTINUED STREAMFLOW STATIONS--Continued Station Station name Drainage Period of number  area (mi2) record   50062500 RÌo Herrera near Colonia Dolores   2.75  1968-72 50063300 RÌo EspÌritu Santo near El Verde   2.23 1968-73 50063500 Quebrada Toronja at El Verde 0.064 1983-96 50065700  RÌo Mameyes at Hwy 191 at Mameyes  11.80 1967-85 50072000 RÌo Fajardo at Fajardo  21.60  1960-63 50073200  RÌo Daguao at Daguao  2.26 1966-82 50073400  Quebrada Palma at Daguao 4.84 1972-77 50074000  RÌo Santiago at Naguabo  4.99  1966-82 50075500 RÌo Blanco at Florida  11.00 1966-82 50076000  RÌo Blanco near Florida   12.30  1983-85 50077000 RÌo Blanco at RÌo Blanco  17.60  1973-77 50077400  RÌo Blanco at Colonia La Fe 18.80  1967-70 50078500 RÌo Anton RuÌz at Central Pasto Viejo 4.33 1968 50081500   RÌo Humacao near Humacao 9.23 1973 50082000 RÌo Humacao at Hwy 3 at Humacao  17.30 1983-85 50082200 RÌo Humacao near La Suiza 19.90  1965-66, 1969-71 50082800 RÌo GuayanÈs near Colonia Laura 4.69  1969-82 50083500 RÌo GuayanÈs near Yabucoa  17.20 1969-71 50084000 RÌo Limones near Yabucoa 7.89  1969-71 50085100 RÌo GuayanÈs at Central Roig 26.60 1965-66, 1968,70 50086100 RÌo del Ingenio at Comunas 5.50 1965-66, 1968-69 50086500 RÌo GuayanÈs at Playa GuayanÈs 34.00 1965-66, 1968-71 50087200 CaÒo Santiago near Central Roig 6.04 1965-71 50091000 RÌo Maunabo at Maunabo  12.40 1965,67, 1969-82 50091200 RÌo Maunabo near Maunabo 12.70 1971-72 50091400 RÌo Jacaboa near Lamboglia 4.13 1965-73 50091700 RÌo Chico at Patillas  6.82 1965, 1969-72 50091800 RÌo Chico at Providencia 4.90 1965, 1967-69, 1971       50094200 RÌo Grande de Patillas at Patillas 27.90 1967, 1969, 1971 50094300 RÌo Grande de Patillas at Providencia 29.00 1971 50094400 RÌo Nigua at Pitahaya 5.86 1965, 1969, 1970-71, 1973 50095200 RÌo GuamanÌ at Guayama 8.22 1969-71 50095500 RÌo GuamanÌ near Guayama 12.30 1969-70                  50099000 Quebrada Aguas Verdes near Salinas 0.39 1989 50106500 RÌo Coamo near Coamo 46.00 1967-68, 1984-85, 1986 50106900 RÌo Coamo below Lago Coamo near Coamo 65.40 1967-68 50107200 RÌo Coamo at mouth near Santa Isabel 69.30 1967-68 50108200 RÌo Descalabrado at Las Ollas 13.90  1965, 1967-71 50108500 RÌo Descalabrado near Santa Isabel 18.10  1966-67 50111200 RÌo Toa Vaca near Villalba  21.40 1966-70 XVI    WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 DISCONTINUED  STREAMFLOW STATIONS--Continued Station Station name Drainage Period of number  area (mi2) record   50111700 RÌo Jacaguas near Juana DÌaz  53.20  1966-68 50111750 RÌo Jacaguas below Quebrada Guan· bana  56.30 1989 50112100 RÌo Jacaguas near Ar˙ s 59.60  1966-67 50112600 RÌo InabÛn at Coto Laurel --  1967-71 50113100 RÌo Guayo near Coto Laurel 11.80 1965, 1968-71 50113500 RÌo InabÛn near Ar˙ s 30.20 1964-65 50114400 RÌo Bucan·  near Ponce  25.60  1965-81 50114700 RÌo Bucan·  near Playa de Ponce 28.40  1964-67 50115000 RÌo PortuguÈs near Ponce 8.82 1964-97 50116500 RÌo PortuguÈs at Highway 2 Bypass at Ponce  20.50 1964-65 50119000 RÌo Matilde at Ponce 19.40 1965-66 50121000 RÌo Tallaboa at PeÒuelas  24.20 1959-82 50122000 RÌo Tallaboa at Tallaboa 31.50  1959-63 50124000 RÌo Guayanilla nr Guayanilla 18.50  1961-69 50124500 RÌo Guayanilla at Guayanilla 20.80 1971-82 50125900 RÌo Duey above Diversion near Yauco 8.93 1977-80 50126150 RÌo Yauco above Diversion Monserrate near Yauco 27.20 1978-85 50128000 RÌo Yauco near Yauco  45.50 1962-64, 1977-85 50129000 RÌo Loco near Yauco  8.50  1963-67 50129500 RÌo Loco near Gu· nica 21.00 1963-69 50129900 Laguna Cartagena near BoquerÛn    -- 1984-86 50130320 Quebrada Mamey at Joyuda 0.38 1986-88 50136000 RÌo Rosario at Rosario  16.40 1975-86 50141000 RÌo Yahuecas near Adjuntas 15.40 1980-85 50145000 RÌo Grande de AÒasco at El Espino 108.00 1959-66, 1961-63 50147000 RÌo Culebrinas at San Sebastian   16.70 1960-82 50214500 Quebrada Resaca near Monte Resaca, Culebra 0.23 1991-93 50215000 Drainage Canal at Culebra Airport, Culebra 0.08 1991-93 50231000 Quebrada ConfresÌ Tributary near Isabel II, Vieques 0.28 1991-93 50232000 Quebrada La Mina near Esperanza, Vieques 0.68 1991-96 50233000 Quebrada PilÛn at Colonia Puerto Real, Vieques 0.67 1991-96 50276000 Turpentine Run at Mariendal, St.Thomas 2.97 1963-69, 1978-86 50292600 Lameshur Bay Gut at Lameshur, St. John 0.38 1992-94 50294000 Fish Bay Gut at Fish Bay, St. John 1.48 1992-94 50295500 Cruz Bay Gut at Cruz Bay, St. John, VI 0.09 1992-93 50332000 River Gut at River 1.42 1991-93 50333500 River Gut near Golden Grove 5.40 1990-93 50333700 River Gut at Hwy 66 at Fairplanes 5.89 1990-96 50334500 Bethehem Gut at Hwy 66 at Fairplanes 4.11 1990-96 50337500 Gut 4.5 at Cane Valley 0.2 1991-93 50348000 Salt River at Canaan 0.36 1991-93 50349000 Gut 10 near Altona   0.13 1991-93                                                                                                                                                                                                                                         1 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 INTRODUCTION The Water Resources Division of the U.S. Geological Survey, in cooperation with local and federal agencies obtains a large amount of data pertaining to the water resources of the Commonwealth of Puerto Rico and the Territory of the U.S. Virgin Islands each water year. These data, accumulated during many water years, constitute a valuable data base for developing an improved understanding of the water resources of the area. To make these data readily available to interested parties outside the U.S. Geological Survey, the data are published annually in this report series entitled "Water Resources Data for Puerto Rico and the U.S. Virgin Islands, 2000." This report includes records on both surface and ground water. Specifically, it contains: (1) discharge records for 85 streamflow gaging stations, daily sediment records for 26 streamflow stations, 21 partial-record or miscellaneous streamflow stations, stage records for 18 reservoirs, and (2) water-quality records for 16 streamflow-gaging stations, and for 42 ungaged stream sites, 11 lake sites, 2 lagoons, and 1 bay, and (3) water-level records for 108 observation wells. Water-resources data for Puerto Rico for calendar years 1958-67 were released in a series of reports entitled "Water Records of Puerto Rico." Water-resources data for the U.S. Virgin Islands for the calendar years 1962-69 were released in a report entitled "Water Records of U.S. Virgin Islands." Included were records of streamflow, ground-water levels, and water-quality data for both surface and ground water. Beginning with the 1968 calendar year, surface-water records for Puerto Rico were released separately on an annual basis. Ground-water level records and water-quality data for surface and ground water were released in companion reports covering periods of several years. Data for the 1973-74 reports were published under separate covers. Water-resources data reports for 1975 to 1999 water years consist of one volume each and contain data for streamflow, water quality, and ground water. Publications similar to this report are published annually by the U.S. Geological Survey for all States. These official Survey reports have an identification number consisting of the two-letter State abbreviation, the last two digits of the water year, and the volume number. For example, this volume is identified as "U.S. Geological Survey Water-Data Report PR-00-1." These water-data reports are for sale in paper copy or in microfiche by the National Technical Information Service, U.S. Department of Commerce, Springfield, Virginia, 22161. Additional information, including current prices, for ordering specific reports may be obtained from the District Chief at the address given on back of the title page or by telephone (787) 749-4346. 2 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 COOPERATION The U.S. Geological Survey has had cooperative agreements with organizations of the Commonwealth of Puerto Rico and the Territory of the U.S. Virgin Islands for the systematic collections of water resources data since 1958. Organizations that supplied data are acknowledged in the station descriptions. Organizations that assisted in collecting data through cooperative agreements with the U.S. Geological Survey are: Puerto Rico Environmental Quality Board Puerto Rico Aqueduct and Sewer Authority Puerto Rico Department of Agriculture Puerto Rico Industrial Development Company Puerto Rico Highway Authority Puerto Rico Department of Natural and Environmental Resources Puerto Rico Department of Health Puerto Rico Electric Power Authority Puerto Rico Solid Waste Management Authority Puerto Rico Legislature Puerto Rico Emergency Management Agency U.S. Virgin Islands Department of Planning and Natural Resources Puerto Rico Infrastructure Financing Authority Funds were also provided by the U.S. Army, Corps of Engineers, for the collection of records at six gaging stations published in this report. 3 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Summary of Hydrologic Conditions Rainfall Rainfall throughout Puerto Rico during the water year 2000 (October 1999 to September 2000) averaged about 105 percent of normal. During the months of October, November, December, January, May, August, and September, rainfall was above normal with averages that ranged from 2 to 83 percent above normal (table 1). During the month of February, March, April, June, and July, rainfall was deficient with averages that ranged from 13 to 66 percent below normal. Rainfall during the water year averaged 92 percent of normal in northern Puerto Rico, 112 percent of normal in southern Puerto Rico, and 111 percent of normal in eastern and western Puerto Rico. Normal rainfall is defined as the mean monthly rainfall for the period 1961-1990 (Table 1 ). Table 1. Islandwide monthly rainfall for the water year 2000 and annual averages for the 30-year reference period, 1961-1990. Data from the National Oceanographic and Atmospheric Administration _________________________________________________ 2000 Water Year 30-year normal Month (inches) (inches) _________________________________________________ October 8.49 8.29 November 11.98 6.55 December 5.64 4.38 January 3.28 2.87 February 2.21 2.53 March 1.33 3.02 April 2.74 4.44 May 7.71 6.96 June 3.03 5.00 July 2.99 5.09 August 7.93 6.89 September 9.12 7.14 TOTAL 66.45 63.16 _________________________________________________ Surface Water Streamflow in Puerto Rico was in general, above normal in water year 2000, based on the index stations. Monthly mean discharges were greater than the long-term median of monthly mean flow during most of the water year. A comparison of the monthly mean flows during the 2000 water year, the long-term median of the monthly mean flows, and the minimum and maximum monthly mean flows for the periods of record at the index stations on the Río Grande de Manatí, the Río Fajardo, the Río Inabón, and the Río Grande de Añasco are shown in figure 1. Historical maximums for the month of November were recorded at three of the four index stations. Hydrologic conditions were similar islandwide from October to January, with monthly-mean flows above the long-term median of the monthly-mean flows, at the four index stations. During this year there were no extraordinary streamflow events, but there was abundant runoff during the entire period. During the months of February to the end of the water year, streamflows were below the long-term median of the monthly-mean flows in some areas, as recorded by the index stations. An overview of the four areas represented by the index stations follows to describe those conditions in more detail. In the northern area, represented by the Río Grande de Manatí index station, the monthly mean flows were well above the long-term median of the monthly-mean flows during the months of October to March, May, and August. Those flows ranged between 17 to 573 percent above normal, with December being the highest. A historical maximum monthly mean flow was recorded during November at this index station. During April, June, July and September, monthly mean flows were below normal, ranging from 16 to 54 percent below the long-term median of the monthly-mean flows. 4 5 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 The eastern area, represented by the index station at the Río Fajardo, recorded monthly mean flows above the long-term median during six of the twelve months of the 2000 water year. At this station, monthly mean flows ranging from 9 to 286 percent above normal were recorded from October to January, May, and August. A historical maximum monthly mean was recorded during the month of November at this index station. During February to April, June, July, and September, the monthly mean flows recorded ranged from 4 to 80 percent below normal. In the southern area, the Río Inabón index station recorded monthly mean flows of the long-term median during ten of the twelve months of the 2000 water year. At this station, only the monthly mean flows for July and August were below the long-term median. The flows were 70 and 82 percent of normal respectly. The rest of the year, monthly mean flows ranged from 105 to 234 percent of the long-term median. In the western area, the index station on the Río Grande de Añasco recorded monthly mean flows above the long-term median during the entire 2000 water year. Monthly mean flows ranged between 1 to 311 percent above the long-term median of the monthly mean flows. The highest was recorded during the month of May with a monthly-mean flow of 411 percent of the long term median. A historical maximum monthly mean flow was recorded during the month of November at this index station. In the U.S. Virgin Islands, rainfall was deficient with only 91 percent of normal reported by the National Oceanic and Atmospheric Administration. Streamflow conditions were similarly below normal. Ground Water Water level trends and fluctuations during the 2000 water year followed a similar pattern as in previous years resulting from above normal rainfall accumulations combined with continuous ground-water withdrawals (figure 2). In water year 2000, only 5 tapedowns were obtained at the Sabana Hoyos well, ground-water station 182647066201700 so the well record is not shown. In this same period, equipment problems were corrected and the station has been converted to a satellite telemetry site. The well record shown in place of the Sabana Hoyos well is that of Tortuguero 3 well, ground-water station 182712066251700 (figure 2). In 30 ground-water monitoring sites, the highest water level recorded approached or was slightly above the historic high (table 2). In areas where the ground-water withdrawals are an important resource for drinking water purposes (table 3) water levels were below the historic low (18 ground-water monitoring sites). The period of record of more than half of the ground-water monitoring wells dates to 1997, when the ground-water monitoring network was established. Fluctuations observed at these monitoring stations during water year 2000 were comparable to historic ground-water levels at index stations established since the 1960's. Figure 7 and 9 show the locations of the ground-water stations maintained by the USGS in Puerto Rico and the U.S. Virgin Islands, in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and other agencies. 6 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Table 2. Highest ground-water levels recorded during 2000 water year and previous high ground-water levels at selected wells in Puerto Rico [PR, Puerto Rico; mm-dd-yy, month-day-year; ft-blsd, feet below land-surface datum; mm-yy, month-year] _____________________________________________________________________________________________________________________ 2000 Previous Highest highest water water Period of Well Local level Date level Date record name number Location (ft-blsd) (mm-dd-yy) (ft-blsd) (mm-dd-yy) (mm-yy) _____________________________________________________________________________________________________________________ Santana 1 1056 PR 101.29 01-07-00 101.60 08-20-97 08-95 to 09-00 PRASA 166 166 PR 21.38 11-21-99 22.11 01-25-97 01-82 to 09-00 USGS Obs. Manatí Piezometer 1102 PR 23.13 12-07-99 23.39 12-06-98 05-96 to 09-00 Tortuguero 3 12-08-99 Ponderosa 1 212 PR 62.21 01-03-00 63.05 07-15-87 10-85 to 09-00 Pampano 2 213 PR 26.27 01-25-00 24.40 12-06-85 10-85 to 09-00 Piezometer 1128 PR 57.63 12-11-99 60.40 09-20-95 02-95 to 09-00 Santa Rosa to USGS 2 12-14-99 Piezometer 1130 PR 29.58 12-08-99 31.10 12-11-98 01-95 to 09-00 Higuillar 4 12-09-99 12-12-98 Piezometer San 1131 PR 12.83 12-07-99 13.97 09-11-96 10-94 to 09-00 Antonio USGS 1 12-08-99 Piezometer San 1132 PR 12.93 12-08-99 13.95 09-11-96 10-94 to 09-00 Antonio USGS 3 Piezometer USGS 652 PR 4.59 05-28-00 5.42 12-05-98 05-97 to 09-00 Bldg. 652 Piezometer 1153 PR 21.97 12-08-99 24.90 02-17-99 04-89 to 09-00 Salud Mental 12-09-99 02-18-99 Piezometer 1154 PR 2.60 11-24-99 3.11 09-18-89 07-89 to 09-00 Alsacia 2 Piezometer 1176 PR 20.75 11-20-99 21.06 12-07-98 06-92 to 09-00 CJ 19A 11-21-99 Piezometer 1180 PR 10.71 01-21-00 12.08 10-16-97 06-97 to 09-00 Caguas-Juncos 18 Piezometer 1203 PR 1.66 11-13-99 2.01 10-22-98 10-97 to 09-00 Carlos Arroyo 1 Piezometer 1207 PR 0.58 12-03-99 1.90 12-30-98 08-97 to 09-00 RF-12 Piezometer 1226 PR +0.29 11-17-99 +0.05 12-09-98 09-97 to 09-00 Yabucoa USGS Brackish Barranca Dug 1229 PR 13.66 11-25-99 18.07 11-05-98 04-97 to 09-00 11-26-99 11-06-98 11-27-99 Piezometer 1231 PR 16.09 11-27-00 19.01 02-17-98 04-88 ot 09-00 Aguirre 11-28-00 02-18-98 HW 1 02-19-98 Piezometer 1233 PR 5.55 11-13-00 5.93 09-03-98 04-88 ot 09-00 Aguirre HW 5B Maunabo 3 1235 PR 3.01 12-09-99 5.17 09-02-99 02-98 to 09-00 Cacao Bajo 1236 PR 14.32 12-09-99 16.22 09-30-99 04-98 to 09-00 Colón Moret 1237 PR 26.22 11-22-99 31.24 06-22-99 06-99 to 09-00 PRASA 1238 PR 16.68 12-31-99 16.95 03-09-99 03-98 to 09-00 Villodas Coqui Battery 1 1251 PR 1.04 11-10-99 3.30 09-22-98 03-97 to 09-00 09-23-98 Cabrera 1 1258 PR 31.93 12-01-99 33.19 12-27-98 03-97 to 09-00 Constancia 3 1276 PR 9.13 09-28-00 10.63 10-23-98 05-96 to 09-00 09-29-00 Albergue de 1277 PR 24.62 12-13-99 27.67 10-23-98 03-92 to 09-00 Niños 1 Hormigueros 1304 PR 4.99 10-15-99 6.08 09-07-99 02-98 to 09-00 Cervecería 1326 PR 4.65 11-24-99 4.69 09-13-99 08-97 to 09-00 India 4 _____________________________________________________________________________________________________________________ 7 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Table 3. Lowest ground-water levels recorded during 2000 water year and previous high ground-water levels at selected wells in Puerto Rico [PR, Puerto Rico; mm/dd/yy, month/day/year; ft-blsd, feet below land-surface datum; mm/yy, month/year] _______________________________________________________________________________________________________________________ 2000 Previous Highest highest water water Period of Well Local level Date level Date record name number Location (ft-blsd) (mm-dd-yy) (ft-blsd) (mm-dd-yy) (mm-yy) _______________________________________________________________________________________________________________________ Zanja 4 1026 PR 338.56 07-07-00 331.20 03-11-98 02-97 to 09-00 Santana Park 1055 PR 52.40 01-26-00 52.09 09-03-99 09-95 to 09-00 NC-5 Cruce 205 PR 90.24 10-08-99 89.97 09-28-99 12-86 to 09-00 Dávila Piezometer Monserrate 2 217 PR 4.24 08-29-00 4.11 06-20-99 11-85 to 09-00 Piezometer 1159 PR 44.38 07-28-00 37.18 12-22-98 12-97 to 09-00 Ft. Buchanan 07-29-00 1 Piezometer 1179 PR 11.11 11-18-99 9.58 05-11-98 05-97 to 09-00 Caguas-Juncos 11-19-99 05-12-98 15 Piezometer 1180 PR 16.27 03-15-00 15.83 05-11-99 06-97 to 09-00 Caguas-Juncos 18 Piezometer 1202 PR 14.52 08-22-00 14.22 05-06-99 09-97 to 09-00 Río Mameyes 08-23-00 05-07-99 2 05-08-99 Piezometer 1203 PR 12.20 08-21-00 11.68 07-08-99 10-97 to 09-00 Carlos 08-22-00 07-09-99 Arroyo 1 Piezometer Quebrada Mata 1208 PR 5.96 08-22-00 5.34 07-30-99 09-97 to 09-00 de Platanos Piezometer 1234 PR 50.72 07-24-00 48.12 09-03-98 04-88 to 09-00 Aguirre HW 13 Cacao Bajo 1236 PR 20.54 05-25-00 20.42 03-23-99 04-98 to 09-00 Colón Moret 1237 PR 39.92 10-21-99 38.91 09-30-99 06-99 to 09-00 PRASA 1 1301 PR 35.91 05-03-00 28.52 05-19-99 05-96 to 09-00 Cabo Rojo 05-04-00 CR-TW-9A 1302 PR 21.76 05-09-00 13.39 06-02-99 07-92 to 09-00 05-10-00 CR-TW-9B 1303 PR 28.61 05-03-00 23.38 05-18-98 07-92 to 09-00 05-04-00 05-19-98 05-20-00 Rincón 4 1352 PR 35.62 06-12-00 34.38 08-19-99 05-96 to 09-00 to 06-15-00 _______________________________________________________________________________________________________________________ 8 October November December January February March April May June July August September 2000 0 20 0 5 10 15 October November December January February March April May June July August September 2000 36 42 36 38 40 October November December January February March April May June July August September 23.0 25.0 23.0 23.5 24.0 24.5 WELL 1102, TORTUGUERO 3 PUERTO RICO WELL 87, ALOMAR WELL, PUERTO RICO WELL 11, GUINEA GUT ST. JOHN U.S. VIRGIN ISLANDS WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 2000 Figure 2. Ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 9 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Water Quality The U.S. Geological Survey, in cooperation with several local government agencies, collected water-quality data at 73 surface- water stations in Puerto Rico during water year 2000. The water-quality data collected at these stations included the major chemical constituents and several others that are listed in table 4. The highest concentration of each of these constituents detected during water year 2000 and the station where it was detected are summarized in table 4. Table 4. Surface-water quality stations in Puerto Rico with highest concentration of selected constituents during water year 2000 [All constituent concentrations are in milligrams per liter; MBAS, Methylene blue active substance] ________________________________________________________________________________ Station number Station name Constituent Concentration ________________________________________________________________________________ 50029000 Río Grande de Arecibo at Central Cambalache Sulfide 1.6 50047530 Río Hondo at Flood Channel Boron 0.44 50143000 Río Grande de Añasco near Lares Manganese 2.3 50143000 Río Grande de Añasco near Lares Iron 33 50055250 Río Cagüitas at hwy 30 near Caguas Zinc 0.21 50055250 Río Cagüitas at hwy 30 near Caguas Cyanide 0.03 50057025 Río Cagüitas at hwy 30 near Caguas Phenols 0.02 50055250 Río Cagüitas at hwy 30 near Caguas MBAS 1.46 The presence of high concentrations of fecal coliform (fig. 3) and fecal streptococcal (fig. 4) bacteria continued to be the principal surface-water quality problem in Puerto Rico during water year 2000 . The highest concentration observed during this year occurred in stations located in the San Juan Metropolitan area which has the highest population concentration in Puerto Rico. In addition to the effluent from the San Juan metropolitan area the streams are also receiving effluents from the upper basin sewage treatment plants. The highest concentration of fecal coliform and fecal streptococcal bacteria in surface waters in Puerto Rico generally occurred in streams draining from densely populated and industrialized areas of the Island. Suspended-sediment concentrations were monitored at 26 stations in Puerto Rico during the 2000 water year as part of the cooperative program between the U.S. Geological Survey and various Commonwealth and Federal agencies. High suspended sediment concentrations are a common problem in many streams in Puerto Rico. Most of the streams with high suspended sediment concentration were related to land use, especially urban development, agriculture and activities where soil movement was involved. The high suspended- sediment concentrations affect the quality of drinking water and the storage capacities of reservoirs. 10 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 SPECIAL NETWORKS AND PROGRAMS Hydrologic Bench-Mark Network is a network of 57 sites in small drainage basins around the country whose purpose is to provide consistent data on the hydrology, including water quality, and related factors in representative undeveloped watersheds nationwide, and to provide analyses on a continuing basis to compare and contrast conditions observed in basins more obviously affected by the activities of man. National Stream Quality Accounting Network (NASQAN) is a nationwide data-collection network designed by the U.S. Geological Survey to meet many of the information needs of government agencies and other groups involved in natural or regional water-quality planning and management. The 500 or so sites on NASQAN are generally located at the downstream ends of hydrologic accounting units designated by the U.S. Geological Survey Office of Water Data Coordination in consultation with the Water Resources Council. The objectives of NASQAN are (1) to obtain information on the quality and quantity of water moving within and from the United States through a systematic and uniform process of data collection, summarization, analysis, and reporting such that the data may be used for, (2) description of the areal variability of water quality in the Nation's rivers through analysis of data from this and other programs, (3) detection of changes or trends with time in the pattern of occurrence of water- quality characteristics, and (4) providing a nationally consistent data base useful for water-quality assessment and hydrologic research. The National Trends Network (NTN) is a 150-station network for sampling atmospheric deposition in the United States. The purpose of the network is to determine the variability, both in location and in time, of the composition of atmospheric deposition, which includes snow, rain, dust particles, aerosols, and gases. The core from which the NTN was built was the already- existing deposition-monitoring network of the National Atmospheric Deposition Program (NADP). The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey is a long-term program with goals to describe the status and trends of water-quality conditions for a large, diverse, and geographically distributed part of the Nation's ground- and surface-water resources, and to identify, describe, and explain the major natural and human factors that affect these observed conditions and trends. Assessment activities have begun in more than one-third of the study units and ultimately will be conducted in 60 study units (major watersheds and aquifer systems) that represent a wide range of environmental settings nationwide and that account for a large percentage of the Nation's water use. A wide array of chemical constituents will be measured in ground water, surface water, streambed sediments, and fish tissues. The coordinated application of comparative hydrologic studies at a wide range of spatial and temporal scales will provide information for decision making by water-resources managers and a foundation for aggregation and comparison of findings to address water-quality issues of regional and national interest. Radiochemical Programs is a network of regularly sampled water-quality stations where samples are collected to be analyzed for radioisotopes. The streams that are sampled represent major drainage basins in the conterminous United States. Tritium Network is a network of stations which has been established to provide baseline information on the occurrence of tritium in the Nation's surface waters. In addition to the surface-water stations in the network, tritium data are also obtained at a number of precipitation stations. The purpose of the precipitation stations is to provide an estimate sufficient for hydrologic studies of the tritium input to the United States. EXPLANATION OF RECORDS The surface- and ground-water records published in this report are for the 2000 water year that began October 1, 1999 and ended September 30, 2000. A calendar of the water year is provided on the inside of the front cover. The records contain streamflow data, water-quality data for surface and ground water, and ground-water-level data. The locations of the stations and wells where the data were collected are shown in figures 3 to 9. The following sections of the introductory text are presented to provide users with a more detailed explanation of how the hydrologic data published in this report were collected, analyzed, computed, and arranged for presentation. 11 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Station Identification Numbers Each data station, whether stream site or well, in this report is assigned a unique identification number. This number is unique in that it applies specifically to a given station and to no other. The number usually is assigned when a station is first established and is retained for that station indefinitely. The systems used by the U.S. Geological Survey to assign identification numbers for surface-water stations and for ground-water well sites differ, but both are based on geographic location. The "downstream order" system is used for regular surface-water stations and the "latitude-longitude" system is used for wells. Downstream Order System Since October 1, 1950, the order of listing hydrologic-station records in Survey reports is in a downstream direction along the main stream. All stations on a tributary entering upstream from a main-stream station are listed before that station. A station on a tributary that enters between two main-stream stations is listed between them. A similar order is followed in listing stations in first rank, second rank, and other ranks of tributaries. As an added means of identification, each hydrologic station and partial-record station has been assigned a station number. These are in the same downstream order used in this report. In assigning station numbers, no distinction is made between partial-record stations and other stations; therefore, the station number for a partial-record station indicates downstream order position in a list made up of both types of stations that may be established; hence, the numbers are not consecutive. The complete 8-digit number for each station such as 50028000, which appears just to the left of the station name, includes the 2-digit part number "50" plus the 6-digit downstream order number "028000." Latitude-Longitude System The 8-digit downstream order station numbers are not assigned to wells and miscellaneous sites where only random water-quality samples or discharge measurements are taken. The well and miscellaneous site numbering system of the U.S. Geological Survey is based on the grid system of latitude and longitude. The system provides the geographic location of the well or miscellaneous site and a unique number for each site. The number consists of 15 digits. The first 6 digits denote the degrees, minutes, and seconds of latitude, the next 7 digits denote degrees, minutes, and seconds of longitude, and the last 2 digits (assigned sequentially) identify the wells or other sites within a 1- second grid. The numbers shown in the grid correspond to the local numbers assigned to each well as visited in the field. An example is well 16 (fig. 10). Laguna Tortuguero Río Culebrinas Río Guajataca Río Camuy Río Grande de Arecibo Río Grande de Manatí Río Cibuco Río de la Plata Río Hondo Río de Bayamón Bahía de San Juan Río Piedras Laguna San José Laguna La Torrecilla Quebrada Blasina Río Grande de Loíza Río Herrera Río Espíritu Santo Río Mameyes Río Sabana Río Juan Martín Río Guayabo Río Grande Río Grande de Añasco Río Yagüez Río Guanajibo Río Loco Río Yauco Río Guayanilla Río Tallaboa Río Matilde Río Portugués Río Bucaná Río Inabón Río Jacaguas Río Cañas Río Descalabrado Río Coamo Río Jueyes Río Salinas Río Seco Río Guamaní Río Nigua Río Grande de Patillas Río Chico Río Jacaboa Río Maunabo Río Fajardo Río Daguao Quebrada Palma Río Santiago Río Blanco Río Antón Ruíz Río Humacao Río Guayanés ATLANTIC OCEAN CARIBBEAN SEA 67°15' 18°30' 15' 18°00' 17°45' 67°00' 45' 30' 15' 66°00' 45' 65°30' FECAL COLIFORM Figure 3. Location of maximum concentration of fecal coliform bacteria at the water-quality sampling sites in Puerto Rico. < 1,000 1,000 - 10,000 10,000 - 100,000 100,000 - 1,000,000 12 EXPLANATION 0 0 10 10 20 KILOMETERS 20 MILES 1 2 3 4 1 2 3 3 1 1 1 1 2 2 2 2 2 4 4 2 1 2 3 2 3 2 1 1 1 1 1 1 3 1 4 3 2 2 3 3 2 2 2 2 1 1 1 1 1 1 1 2 2 4 3 3 3 1 1 3 3 3 3 3 3 2 1 3 2 2 1 1 2 2 2 3 3 Laguna Tortuguero Río Culebrinas Río Guajataca Río Camuy Río Grande de Arecibo Río Grande de Manatí Río Cibuco Río de la Plata Río Hondo Río de Bayamón Bahía de San Juan Río Piedras Laguna San José Laguna La Torrecilla Quebrada Blasina Río Grande de Loíza Río Herrera Río Espíritu Santo Río Mameyes Río Sabana Río Juan Martín Río Guayabo Río Grande Río Grande de Añasco Río Yagüez Río Guanajibo Río Loco Río Yauco Río Guayanilla Río Tallaboa Río Matilde Río Portugués Río Bucaná Río Inabón Río Jacaguas Río Cañas Río Descalabrado Río Coamo Río Jueyes Río Salinas Río Seco Río Guamaní Río Nigua Río Grande de Patillas Río Chico Río Jacaboa Río Maunabo Río Fajardo Río Daguao Quebrada Palma Río Santiago Río Blanco Río Antón Ruíz Río Humacao Río Guayanés ATLANTIC OCEAN CARIBBEAN SEA 67°15' 18°30' 15' 18°00' 17°45' 67°00' 45' 30' 15' 66°00' 45' 65°30' FECAL STREPTOCOCCI Figure 4. Location of maximum concentration of fecal streptococci bacteria at the water-quality sampling sites in Puerto Rico. < 1,000 1,000 - 10,000 10,000 - 100,000 100,000 - 1,000,000 13 EXPLANATION 0 0 10 10 20 KILOMETERS 20 MILES 1 2 3 4 1 2 4 3 3 2 2 3 3 1 1 1 1 2 1 2 2 1 1 1 1 1 1 2 1 3 1 3 3 3 1 2 2 2 3 2 2 1 1 2 1 1 2 2 1 2 2 2 3 3 3 2 3 2 1 1 1 2 2 1 1 3 2 1 3 1 1 1 2 1 1 3 3 Laguna Tortuguero Río Culebrinas Río Guajataca Río Camuy Río Grande de Arecibo Río Grande de Manatí Río Cibuco Río de la Plata Río Hondo Río de Bayamón Bahía de San Juan Río Piedras Laguna San José Laguna La Torrecilla Quebrada Blasina Río Grande de Loíza Río Herrera Río Espíritu Santo Río Mameyes Río Sabana Río Juan Martín Río Guayabo Río Grande Río Grande de Añasco Río Yagüez Río Guanajibo Río Loco Río Yauco Río Guayanilla Río Tallaboa Río Matilde Río Portugués Río Bucaná Río Inabón Río Jacaguas Río Cañas Río Descalabrado Río Coamo Río Jueyes Río Salinas Río Seco Río Guamaní Río Nigua Río Grande de Patillas Río Chico Río Jacaboa Río Maunabo Río Fajardo Río Daguao Quebrada Palma Río Santiago Río Blanco Río Antón Ruíz Río Humacao Río Guayanés ATLANTIC OCEAN CARIBBEAN SEA 67°15' 18°30' 15' 18°00' 17°45' 67°00' 45' 30' 15' 66°00' 45' 65°30' Figure 5. Location of surface-water stations in Puerto Rico. CONTINUOUS STREAMFLOW STATION AND NUMBER LAKE-ELEVATION STATION AND NUMBER SEDIMENT STATION AND NUMBER 093045 053025 0905 14 EXPLANATION 0 0 10 10 20 KILOMETERS 20 MILES 0710 0618 0570 0550 0551 047850 047550 0438 032290 111210 113950 1002 1061 1080 1115 1113 114390 1138 1149 1159 1242 0201 1289 1415 0108 125780 1364 1380 1125 100450 0920 039990 093045 038320 0395 0381 027750 0284 0290 0280 0148 0105 1478 148890 1440 0350 0312 0340 0590 059050 048770 048680 048690 0491 0460 045010 0450 0564 0810 051310 0509 053025 051150 051180 0655 0670 0660 063440 074950 0750 0705 0638 131990 1140 026140 0271 026025 047560 047540 047535 0642 0518 0905 055750 055225 055390 058350 030460 1109 032590 024950 0217 0205 021030 025850 025155 0270 0264 0930 Laguna Tortuguero Río Culebrinas Río Guajataca Río Camuy Río Grande de Arecibo Río Grande de Manatí Río Cibuco Río de la Plata Río Hondo Río de Bayamón Bahía de San Juan Río Piedras Laguna San José Laguna La Torrecilla Quebrada Blasina Río Grande de Loíza Río Herrera Río Espíritu Santo Río Mameyes Río Sabana Río Juan Martín Río Guayabo Río Grande Río Grande de Añasco Río Yagüez Río Guanajibo Río Loco Río Yauco Río Guayanilla Río Tallaboa Río Matilde Río Portugués Río Bucaná Río Inabón Río Jacaguas Río Cañas Río Descalabrado Río Coamo Río Jueyes Río Salinas Río Seco Río Guamaní Río Nigua Río Grande de Patillas Río Chico Río Jacaboa Río Maunabo Río Fajardo Río Daguao Quebrada Palma Río Santiago Río Blanco Río Antón Ruíz Río Humacao Río Guayanés ATLANTIC OCEAN CARIBBEAN SEA 67°15' 18°30' 15' 18°00' 17°45' 67°00' 45' 30' 15' 66°00' 45' 65°30' CHEMICAL STATION AND NUMBER (Quaterly) BIOLOGICAL STATION AND NUMBER (Quaterly) SEDIMENT STATION AND NUMBER 0550 0910 0918 Figure 6. Location of water-quality stations in Puerto Rico. 15 EXPLANATION 0725 0710 0820 0865 0835 0910 0918 0920 0399 0430 0312 0307 1065 1140 1162 1150 1247 1336 1364 1388 1440 1491 1430 1476 0114 0110 010790 010720 1460 1380 1297 0250 025110 027090 027250 026050 0355 0381 0290 0280 0105 0205 020050 035950 0440 0444 0460 0382 0395 044850 038320 044950 039950 0550 0476 047537 047549 0575 0554 0588 0590 0591 0503 0491 0488 047990 047530 048510 049820 049920 057025 055250 0638 0 0 10 10 20 KILOMETERS 20 MILES 024950 Laguna Tortuguero Río Culebrinas Río Guajataca Río Camuy Río Grande de Arecibo Río Grande de Manatí Río Cibuco Río de la Plata Río Hondo Río de Bayamón Bahía de San Juan Río Piedras Laguna San José Laguna La Torrecilla Quebrada Blasina Río Grande de Loíza Río Herrera Río Espíritu Santo Río Mameyes Río Sabana Río Juan Martín Río Guayabo Río Grande Río Grande de Añasco Río Yagüez Río Guanajibo Río Loco Río Yauco Río Guayanilla Río Tallaboa Río Matilde Río Portugués Río Bucaná Río Inabón Río Jacaguas Río Cañas Río Descalabrado Río Coamo Río Jueyes Río Salinas Río Seco Río Guamaní Río Nigua Río Grande de Patillas Río Chico Río Jacaboa Río Maunabo Río Fajardo Río Daguao Quebrada Palma Río Santiago Río Blanco Río Antón Ruíz Río Humacao Río Guayanés ATLANTIC OCEAN CARIBBEAN SEA 67°15' 18°30' 15' 18°00' 17°45' 67°00' 45' 30' 15' 66°00' 45' 65°30' WELL AND NUMBER YDO-1 Figure 7. Location of ground-water stations in Puerto Rico. 16 EXPLANATION 222 1201 1204 1208 1205 1207 1203 1202 1131 1132 1129 1130 1128 1127 1126 212 213 211 204 207 166 1103 1077 1076 1101 1102 210 206 219 1151 1159 217 216 1133 70 1152 1153 1154 1155 1158 1156 96 1226 1235 6 1251 1254 1258 1257 1256 1237 1236 1228 1229 1239 1238 1230 1252 1260 1134 1253 87 132 143 1279 1231 1233 1232 1234 200 1352 165 1001 202 1026 1051 1027 1055 1056 1052 1053 1054 205 1057 50 141 1258 1239 1276 1277 1278 1176 1177 1179 1178 1181 1180 1301 1302 1303 1304 1326 0 0 10 10 20 KILOMETERS 20 MILES + 18°22 00
 64°42 00
 64°47 00
 18°22 00
 18°19 00
 65°00 00
 65°55 00
 17°45 00
 17°41 00
 18°19 00
 64°48 00
 64°40 30
 Bonne Resolution Jolly Hill Gut Salt River Cob Gut Guinea Bay Gut Gut Gut Battery Fish T u r p en tine Run Westend Saltpond ST. CROIX EXPLANATION Green Cay CHRISTIANSTED FREDERIKSTED C A R I B B E A N S E A C A R I B B E A N S E A Buck Island ST. JOHN C A R I B B E A N S E A A T L A N T I C O C E A N Flannagan Island Coral Bay Whistling Cay Congo Cay Lovango Cay Windward Passage Pillsbury Sound Durloe Cays Leduck Island S a b b a t n Cha n e l CRUZ BAY ST. THOMAS Sula Cay Capella Islands Little St. James I Dog Island Great St. James I Shark Island Mingo Cay Grass Cay CHARLOTTE AMALIE A T L A N T I C O C E A N C A R I B B E A N S E A Cricket Rock Cockroach Island Dutchcap Cay Salt Cay West Cay Kalkun Cay Savana Island Turtledove Cay Saba Island Flat Cays Outer Brass Island Hans Lollik Island Little Hans Lollik Island Water Island 1 2 MILES 1 2 KILOMETERS 0 0 1 2 MILES 1 2 KILOMETERS 0 0 1 2 MILES 1 2 KILOMETERS 0 0 17 Figure 8. Location of surface-water stations in the U.S. Virgin Islands. SURFACE-WATER STATION AND NUMBER EXPLANATION 3450 3450 2950 2520 2740 + 18°22 00
 64°42 00
 64°47 00
 18°22 00
 18°19 00
 65°00 00
 65°55 00
 17°45 00
 17°41 00
 18°19 00
 64°48 00
 64°40 30
 Bonne Resolution 18 Jolly Hill Gut Salt River Cob Gut Guinea Bay Gut Gut Gut Battery Fish T u r p en tine Run Westend Saltpond ST. CROIX Figure 9. Location of ground-water stations in the U.S. Virgin Islands. WELL AND WELL NUMBER EXPLANATION 2 Green Cay CHRISTIANSTED FREDERIKSTED C A R I B B E A N S E A C A R I B B E A N S E A Buck Island ST. JOHN C A R I B B E A N S E A A T L A N T I C O C E A N Flannagan Island Coral Bay Whistling Cay Congo Cay Lovango Cay Windward Passage Pillsbury Sound Durloe Cays Leduck Island S a b b a t n Cha n e l CRUZ BAY ST. THOMAS Sula Cay Capella Islands Little St. James I Dog Island Great St. James I Shark Island Mingo Cay Grass Cay CHARLOTTE AMALIE A T L A N T I C O C E A N C A R I B B E A N S E A Cricket Rock Cockroach Island Dutchcap Cay Salt Cay West Cay Kalkun Cay Savana Island Turtledove Cay Saba Island Flat Cays Outer Brass Island Hans Lollik Island Little Hans Lollik Island Water Island 1 2 MILES 1 2 KILOMETERS 0 0 1 2 MILES 1 2 KILOMETERS 0 0 1 2 MILES 1 2 KILOMETERS 0 0 2 3 13 11 8 6 19 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Figure 10. Grid showing system for numbering wells and miscellaneous sites (latitude and longitude). Records of Stage and Water Discharge Records of stage and water discharge may be complete or partial. Complete records of discharge are those obtained using a continuous stage-recording device through which either instantaneous or mean daily discharges may be computed for any time, or any period of time, during the period of record. Complete records of lake or reservoir content, similarly, are those for which stage or content may be computed or estimated with reasonable accuracy for any time, or period of time. They may be obtained using a continuous stage-recording device, but need not be. Because daily mean discharges and end-of-day contents commonly are published for such stations, they are referred to as "daily stations." By contrast, partial records are obtained through discrete measurements without using a continuous stage-recording device and pertain only to a few flow characteristics, or perhaps only one. The nature of the partial record is indicated by table titles such as "Low-flow partial records." Records of miscellaneous discharge measurements or of measurements from special studies, such as low-flow seepage studies, may be considered as partial records, but they are presented separately in this type of report. Location of all complete-record stations for which data are given in this report are shown in figures 5 and 8. Data Collection and Computation The data obtained at a complete-record gaging station on a stream or canal consists of a continuous record of stage, individual measurements of discharge throughout a range of stages, and notations regarding factors that may affect the relationships between stage and discharge. These data, together with supplemental information, such as weather records, are used to compute daily discharges. The data obtained at a complete-record gaging station on a lake or reservoir consist of a record of stage and of notations regarding factors that may affect the relationship between stage and lake content. These data are used with stage-area and stage-capacity curves or tables to compute water-surface areas and lake storage. Continuous records of stage are obtained with analog recorders that trace continuous graphs of stage or with digital recorders that punch stage values on paper tapes at selected time intervals or electronic satellite data collector platforms that receive stage values at selected time intervals. Measurements of discharge are made with current meters using methods adapted by the Geological Survey as a result of experience accumulated since 1880. These methods are described in standard textbooks, in Water- Supply Paper 2175, and in U.S. Geological Survey Techniques of Water-Resources Investigations, Book 3, Chapter A6. 134 132 131 27 74 16 COORDINATES FOR WELLS 27 (180150066474900) AND 74 (180135066471000) COORDINATES FOR WELLS 132 (180133066503300 AND 134 (180120066503200) COORDINATES FOR WELLS 131 (180058066502700 COORDINATES FOR WELLS 16 (175922066495800) 20 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 In computing discharge records, results of individual measurements are plotted against the corresponding stages, and stage-discharge relation curves are then constructed. From these curves, rating tables indicating the approximate discharge for any stage within the range of the measurements are prepared. If it is necessary to define extremes of discharge outside the range of the current-meter measurements, the curves are extended using: (1) logarithmic plotting; (2) velocity-area studies; (3) results of indirect measurements of peak discharge, such as slope-area or contracted-opening measurements, and computations of flow-over-dams or weirs; or (4) step-backwater techniques. Daily mean discharges are computed by applying the daily mean stages (gage heights) to the stage-discharge curves or tables. If the stage-discharge relation is subject to change because of frequent or continual change in the physical features that form the control, the daily mean discharge is determined by the shifting-control method, in which correction factors based on the individual discharge measurements and notes of the personnel making the measurements are applied to the gage heights before the discharges are determined from the curves or tables. This shifting-control method also is used if the stage-discharge relation is changed temporarily because of aquatic growth or debris on the control. At some stations the stage-discharge relation is affected by changing stage; at these stations the rate of change in stage is used as a factor in computing discharge. In computing records of lake or reservoir contents, it is necessary to have available from surveys, curves or tables defining the relationship of stage and contents. The application of stage to the stage-content curves or tables gives the contents from which daily, monthly or yearly changes then are determined. If the stage-content relationship changes because of deposition of sediment in a lake or reservoir, periodic surveys may be necessary to redefine it. Even when this is done, as time between the last survey increases, the contents computed may increase in error. Discharges over lake or reservoir spillways are computed from stage- discharge relationships much as other stream discharges are computed. For some gaging stations there are periods when no gage-height record is obtained, or the recorded gage height is so faulty that it cannot be used to compute daily discharge or contents. This happens when the recorder stops or otherwise fails to operate properly, intakes are plugged, the float is loose in the well, or for various other reasons. For such periods, the daily discharges are estimated from the recorded range in stage, previous or following record, discharge measurements, weather records, and comparison with other station records from the same or nearby basins. Likewise, daily contents may be estimated from operator's logs, previous or following record, inflow-outflow studies, and other information. Information explaining how estimated daily- discharge values are identified in station records is included in the next two sections, "Data Presentation" (REMARKS paragraph) and "Identifying Estimated Daily Discharge." Data Presentation Steamflow data in this report are presented in a new format that is considerably different from the format in data reports prior to the 1992 water year. The major changes are that statistical characteristics of discharge now appear in tabular summaries following the water-year data table and less information is provided in the text or station manuscript above the table. These changes represent the results of a pilot program to reformat the annual water-data report to meet current user needs and data preferences. The records published for each continuous-record surface-water discharge station (gaging station) now consist of four parts, the manuscript or station description; the data table of daily mean values of discharge for the current water year with summary data; a tabular statistical summary of monthly mean flow data for a designated period, by water year; and a summary statistics table that includes statistical data of annual, daily, and instantaneous flows as well as data pertaining to annual runoff, 7-day low-flow minimum, and flow duration. Station manuscript The manuscript provides, under various headings, descriptive information, such as station location; period of record; historical extremes outside the period of record; record accuracy; and other remarks pertinent to station operation and regulation. The following information, as appropriate, is provided with each continuous record of discharge or lake content. Comments to follow clarify information presented under the various headings of the stations descriptions. LOCATION.--Information on locations is obtained from the most accurate maps available. The location of the gage with respect to the cultural and physical features in the vicinity and with respect to the reference place mentioned in the station name is given. 21 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 DRAINAGE AREA.--Drainage areas are measured using the most accurate maps available. Drainage areas are updated as better maps become available. PERIOD OF RECORD.--This indicates the period for which there are published records for the station or for an equivalent station. An equivalent station is one that was in operation at a time that the present station was not, and whose location was such that records from it can reasonable be considered equivalent with records from the present station. REVISED RECORDS.--Because of new information, published records occasionally are found to be incorrect, and revisions are printed in later reports. Listed under this heading are all the reports in which revisions have been published for the station and the water years to which the revisions apply. If a revision did not include daily, monthly, or annual figures of discharge, that fact is noted after the year dates as follows: "(M)" means that only the instantaneous maximum discharge was revised; "(m)" that only the instantaneous minimum was revised; and "(P)" that only peak discharges were revised. If the drainage area has been revised, the report in which the most recently revised figure was first published is given. GAGE.--The type of gage in current use, the datum of the current gage, and a condensed history of the types, locations, and datums of previous gages are given under this heading. REMARKS.--All periods of estimated daily-discharge record will either be identified by date in this paragraph of the station description for water-discharge stations or flagged in the daily-discharge table. (See next section, "Identifying Estimated Daily Discharge.") If a remarks statement is used to identify estimated record, the paragraph will begin with this information presented as the first entry. The paragraph is also used to present information relative to the accuracy of the records, to special methods of computations, to conditions that affect natural flow at the station and, possibly, to other pertinent items. For reservoir stations, information is given on the dam forming the reservoir, the capacity, outlet works and spillway, and purpose and use of the reservoir. COOPERATION.--Records provided by a cooperating organization or obtained for the Geological Survey by a cooperating organization are identified here. EXTREMES OUTSIDE PERIOD OF RECORD.--Included here is information concerning major floods or unusually low flows that occurred outside the stated period of record. The information may or may not have been obtained by the U.S. Geological Survey. REVISIONS.--If a critical error in published records is discovered, a revision is included in the first report published following discovery of the error. Although rare, occasionally the records of a discontinued gaging station may need revision. Because, for these stations, there would be no current or, possibly, future station manuscript published to document the revision in a "Revised Records" entry, users of data for these stations who obtained the record from previously published data reports may wish to contact the District office to determine if the published records were ever revised after the station was discontinued. Of course, if the data were obtained by computer retrieval, the data would be current and there would be no need to check because any published revision of data is always accompanied by revision of the corresponding data in computer storage. Manuscript information for lake or reservoir stations differs from that for stream stations in the nature of the "Remarks" and in the inclusion of a skeleton stage-capacity table when daily contents are given. Data table of daily mean value The daily table of discharge records for stream gaging stations gives mean discharge for each day of the water year. In the monthly summary for the table, the line headed "TOTAL" gives the sum of the daily figures for each month; the line headed "MEAN" gives the average flow in cubic feet per second for the month; and the lines headed "MAX" and "MIN" give the maximum and minimum daily mean discharges, respectively, for each month. Discharge for the month also is usually expressed in cubic feet per second per square mile (line headed "CFSM"); or in inches (line headed "IN"); or in acre-feet (line headed "AC-FT"). Figures for cubic feet per second per square mile and runoff in inches or in acre-feet may be omitted if there is extensive regulations or diversion or if the drainage area includes large noncontributing areas. 22 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Statistics of monthly mean data A tabular summary of the mean (line headed "MEAN"), maximum (line headed "MAX"), and minimum (line headed "MIN") of monthly mean flows for each month for a designated period is provided below the mean values table. The water years of the first occurrence of the maximum and minimum monthly flow are provided immediately below those figures. The designated period will be expressed as "FOR WATER YEARS ____-____, BY WATER YEAR (WY)," and will list the first and last water years of the range of years selected from the PERIOD OF RECORD paragraph in the station manuscript. It will consist of all of the station records within the specified water years, including complete months of record for partial water years, if any, and may coincide with the period of record for the station. The water years for which the statistics are computed will be consecutive, unless a break in the station record is indicated in the manuscript. Summary statistics A table titled "SUMMARY STATISTICS" follows the statistics of monthly mean data tabulation. This table consists of four columns, with the first column containing the line headings of the statistics being reported. The table provides a statistical summary of yearly, daily, and instantaneous flows, not only for the current water year but also for the previous calendar year and for a designated period, as appropriate. The designated period selected, "WATER YEARS ____-____," will consist of all of the station records within the specified water years, inclusive, including complete months of record for partial water years, if any, and may coincide with the period of record for the station. The water years for which the statistics are computed will be consecutive, unless a break in the station record is indicated in the manuscript. All of the calculations for the statistical characteristics designated ANNUAL (see line headings below), except for the "ANNUAL 7-DAY MINIMUM" statistic, are calculated for the designated period using complete water years. The other statistical characteristics may be calculated using partial water years. The date or water year, as appropriate, of the first occurrence of each statistic reporting extreme values of discharge is provided adjacent to the statistic. Repeated occurrences may be noted in the REMARKS paragraph of the manuscript or in footnotes. Because the designated period may not be the same as the station period of record published in the manuscript, occasionally the dates of occurrence listed for the daily and instantaneous extremes in the designated-period column may not be within the selected water years listed in the heading. When this occurs, it will be noted in the REMARKS paragraph or in footnotes. Selected streamflow duration curve statistics and runoff data are also given. Runoff data may be omitted if there is extensive regulation or diversion of flow in the drainage basin. The following summary statistics data, as appropriate, are provided with each continuous record of discharge. Comments to follow clarify information presented under the various line headings of the summary statistics table. ANNUAL TOTAL.--The sum of the daily mean values of discharge for the year. At some stations the annual total discharge is adjusted for reservoir storage or diversion. The adjusted figures are identified by a symbol and corresponding footnotes. ANNUAL MEAN.--The arithmetic mean of the individual daily mean discharges for the year noted or for the designated period. At some stations the yearly mean discharge is adjusted for reservoir storage or diversion. The adjusted figures are identified by a symbol and corresponding footnotes. HIGHEST ANNUAL MEAN.--The maximum annual mean discharge occurring for the designated period. LOWEST ANNUAL MEAN.--The minimum annual mean discharge occurring for the designated period. HIGHEST DAILY MEAN.--The maximum daily mean discharge for the year or for the designated period. LOWEST DAILY MEAN.--The minimum daily mean discharge for the year or for the designated period. ANNUAL 7-DAY MINIMUM.--The lowest mean discharge for 7 consecutive days for a calendar year or a water year. Note that most low-flow frequency analyses of annual 7-day minimum flows use a climatic year (April 1 - March 31). The date shown in the summary statistics table is the initial date of the 7-day period. (This value should not be confused with the 7-day 10-year low-flow statistics). 23 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 INSTANTANEOUS PEAK FLOW.--The maximum instantaneous discharge occurring for the water year or for the designated period. Note that secondary instantaneous peak discharges above a selected base discharge are stored in District computer files for stations meeting certain criteria. Those discharge values may be obtained by writing to the District Office. (See address on back of the title page of this report.) INSTANTANEOUS PEAK STAGE.--The maximum instantaneous stage occurring for the water year or for the designated period. If the dates of occurrence for the instantaneous peak flow and instantaneous peak stage differ, the REMARKS paragraph in the manuscript or a footnote may be used to provide further information. INSTANTANEOUS LOW FLOW.--The minimum instantaneous discharge occurring for the water year or for the designated period. ANNUAL RUNOFF.--Indicates the total quantity of water in runoff for a drainage area for the year. Data reports may use any of the following units of measurements in presenting annual runoff data: Acre-foot (AC-FT) is the quantity of water required to cover 1 acre to a depth of 1 foot and is equivalent to 43,560 cubic feet or about 326,000 gallons or 1,233 cubic meters. Cubic feet per second per square mile (CFSM) is the average number of cubic feet of water flowing per second from each square mile of area drained, assuming the runoff is distributed uniformly in time and area. Inches (INCHES) indicates the depth to which the drainage area would be covered if all of the runoff for given time period were uniformly distributed on it. 10 PERCENT EXCEEDS.--The discharge that is exceeded 10 percent of the time for the designated period. 50 PERCENT EXCEEDS.--The discharge that is exceeded 50 percent of the time for the designated period. 90 PERCENT EXCEEDS.--The discharge that is exceeded 90 percent of the time for the designated period. Data collected at partial-record stations follow the information for continuous-record sites. Data for partial-record discharge stations are presented in a table of discharge measurements at low-flow partial-record stations. These measurements are generally made in times of drought to give better areal coverage to those events. Those measurements and others collected for some special reason are called measurements at miscellaneous sites. Identifying Estimated Daily Discharge Estimated daily-discharge values published in the water-discharge tables are identified by flagging individual daily values with the letter symbol "e" and printing a table footnote, "e Estimated." Accuracy of the Records The accuracy of streamflow records depends primarily on: (1) The stability of the stage-discharge relation or, if the control is unstable, the frequency of discharge measurements; and (2) the accuracy of measurements of stage, measurements of discharge, and interpretation of records. The accuracy attributed to the records is indicated under "REMARKS." "Excellent" means that about 95 percent of the daily discharges are within 5 percent of the true; "good," within 10 percent; and "fair," within 15 percent. Records that do not meet the criteria mentioned, are rated "poor." Different accuracies may be attributed to different parts of a given record. Daily mean discharges in this report are given to the nearest hundredth of a cubic foot per second for values less than 1 ft3/s; to the nearest tenth between 1.0 and 10 ft3/s; to whole numbers between 10 and 1,000 ft3/s; and to 3 significant figures for more than 1,000 ft3/s. The number of significant figures used is based solely on the magnitude of the discharge value. The same rounding rules apply to discharges listed for partial-record stations and miscellaneous sites. 24 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Information used in the preparation of the records in this publication, such as discharge-measurement notes, gage-height records, temperature measurements, and rating tables are on file in the Caribbean District office. Also, most of the daily mean discharges are in computer-readable form and have been analyzed statistically. Information on the availability of the unpublished information or on the results of statistical analyses of the published records may be obtained from the District office. Records of Surface-Water Quality Records of surface-water quality ordinarily are obtained at or near stream gaging stations because interpretation of records of surface-water quality nearly always requires corresponding discharge data. Records of surface-water quality in this report may involve a variety of types of data and measurement frequencies. Classification of Records Water-quality data for surface-water sites are grouped into one of three classifications. A continuing-record station is a site where data are collected on a regularly scheduled basis. Frequency may be once or more times daily, weekly, monthly, or quarterly. A partial-record station is a site where limited water-quality data are collected systematically over a period of years. Frequency of sampling is usually less than quarterly. A miscellaneous sampling site is a location other than a continuing or partial- record station, where random samples are collected to give better areal coverage to define water-quality conditions in the river basin. A careful distinction needs to be made between "continuing records" as used in this report and "continuous recordings," which refers to a continuous graph or a series of discrete values punched at short intervals on a paper tape. Some records of water quality, such as temperature and specific conductance, may be obtained through continuous recordings; however, because of costs, most data are obtained only monthly or less frequently. Locations of stations for which records on the quality of surface water appear in this report are shown in figure 6. Arrangement of Records Water-quality records collected at a surface-water daily record station are published immediately following that record, regardless of the frequency of sample collection. Station number and name are the same for both records. Where a surface-water daily record station is not available or where the water quality differs significantly from that at the nearby surface-water station, the continuing water-quality record is published with its own station number and name in the regular downstream-order sequence. Water-quality data for partial-record stations and for miscellaneous sampling sites appear in separate tables following the table of discharge measurement at miscellaneous sites. On-site Measurements and Sample Collection In obtaining water-quality data, a major concern needs to be assuring that the data obtained represent the in situ quality of the water. To assure this, certain measurements, such as water temperature, pH, and dissolved oxygen, need to be made onsite when the samples are taken. To assure that measurements made in the laboratory also represent the in situ water, carefully prescribed procedures need to be followed in collecting the samples, in treating the samples to prevent changes in quality pending analysis, and in shipping the samples to the laboratory. Procedures for onsite measurements and for collecting, treating, and shipping samples are given in publications on "Techniques of Water-Resources Investigations," Book 1, Chap. D2; Book 3, Chap. C2; Book 5, Chap. A1, A3, and A4. Detailed information on collecting, treating, and shipping samples may be obtained from the Geological Survey District office. One sample can define adequately the water quality at a given time if the mixture of solutes throughout the stream cross section is homogeneous. However, the concentration of solutes at different locations in the cross section may vary widely with different rates of water discharge, depending on the source of material and the turbulence and mixing of the stream. Some streams must be sampled through several vertical sections to obtain a representative sample needed for an accurate mean concentration and for use in calculating load. All samples obtained for the National Stream Quality Accounting Network (see definitions) are obtained from at least several verticals. Whether samples are obtained from the centroid of flow or from several verticals, depends on flow conditions and other factors which must be evaluated by the collector. 25 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Chemical-quality data published in this report are considered to be the most representative values available for the stations listed. The values reported represent water-quality conditions at the time of sampling as much as possible, consistent with available sampling techniques and methods of analysis. In the rare case where an apparent inconsistency exists between a reported pH value and the relative abundance of carbon dioxide species (carbonate and bicarbonate), the inconsistency is the result of a slight uptake of carbon dioxide from the air by the sample between measurement of pH in the field and determination of carbonate and bicarbonate in the laboratory. For chemical-quality stations equipped with digital monitors, the records consist of daily maximum, minimum, and mean values for each constituent measured and are based upon hourly punches beginning at 0100 hours and ending at 2400 hours for the day of record. More detailed records, when available, (hourly values) may be obtained from the U.S.G.S. District office whose address is given on the back of the title page of this report. Water Temperature Water temperatures are measured at most of the water-quality stations. In addition, water temperatures are taken at time of discharge measurements for water-discharge stations. For stations where water temperatures are taken manually once or twice daily, the water temperatures are taken at about the same time each day. Large streams have a small diurnal temperature change; shallow streams may have a daily range of several degrees and may follow closely the changes in air temperature. Some streams may be affected by waste-heat discharges. At stations where recording instruments are used, either mean temperatures or maximum and minimum temperatures for each day are published. Water temperatures measured at the time of water-discharge measurements are on file in the District office. Sediment Suspended-sediment concentrations are determined from samples collected by using depth-integrating and pumping sediment samplers. Samples usually are obtained at several verticals in the cross section, or a single sample may be obtained at a fixed point and a coefficient applied to determine the mean concentration in the cross sections. During periods of rapidly changing flow or rapidly changing concentration, samples may have been collected more frequently (twice daily or hourly). The published sediment discharges for days of rapidly changing flow or concentration were computed by the subdivided-day method (time-discharge weighted average). Therefore, for those days when the published sediment discharge value differs from the value computed as the product of discharge times mean concentration times 0.0027, the reader can assume that the sediment discharge for that day was computed by the subdivided-day method. For periods when no samples were collected, daily discharges of suspended sediment were estimated on the basis of water discharge, sediment concentrations observed immediately before and after the periods, suspended-sediment loads for other periods of similar discharge, and computed by the subdivided-day method using the transport curves. At other stations, suspended-sediment samples were collected periodically at many verticals in the stream cross section. Although data collected periodically may represent conditions only at the time of observations, such data are useful in establishing seasonal relations between quality and streamflow and in predicting long-term sediment-discharge characteristics of the stream. In addition to the records of suspended-sediment discharge, records of the periodic measurements of the particle-size distribution of the suspended sediment are included for some stations. Laboratory Measurements Sediment samples, samples for biochemical-oxygen demand (BOD), samples for indicator bacteria, and daily samples for specific conductance are analyzed locally. All other samples are analyzed in the Geological Survey laboratories in Denver, Co. or Ocala, Fla. Methods used in analyzing sediment samples and computing sediment records are given in TWRI, Book 5, Chap. C1. Methods used by the Geological Survey laboratories are given in TWRI, Book 1, Chap. D2; Book 3, Chap. C2; Book 5, Chap. A1, A3, and A4. 26 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Data Presentation For continuing-record stations, information pertinent to the history of station operation is provided in descriptive headings preceding the tabular data. These descriptive headings give details regarding location, drainage area, period of record, type of data available, instrumentation, general remarks, cooperation, and extremes for parameters currently measured daily. Tables of chemical, physical, biological, radiochemical data, and so forth, obtained at a frequency less than daily are presented first, and tables of "daily values" of specific conductance, pH, water temperature, dissolved oxygen, and suspended sediment then follow in sequence, when these parameters are studied. In the descriptive headings, if the location is identical to that of the discharge gaging station, neither the LOCATION nor the DRAINAGE AREA statements are repeated. The following information, as appropriate, is provided with each continuous- record station. Comments that follow clarify information presented under the various headings of the station description. LOCATION.--See Data Presentation under "Records of Stage and Water Discharge;" same comments apply. DRAINAGE AREA.--See Data Presentation under "Records of Stage and Water Discharge;" same comments apply. PERIOD OF RECORD.--This indicates the periods for which there are published water-quality records for the station. The periods are shown separately for records of parameters measured daily or continuously and those measured less than daily. For those measured daily or continuously, periods of record are given for the parameters individually. INSTRUMENTATION.--Information on instrumentation is given only if a water-quality monitor temperature record, sediment pumping sampler, or other sampling device is in operation at a station. REMARKS.--Remarks provide added information pertinent to the collection, analysis, or computation of the records. COOPERATION.--Records provided by a cooperating organization or obtained for the Geological Survey by a cooperating organization are identified here. EXTREMES.--Maximums and minimums are given only for parameters measured daily or more frequently. None are given for parameters measured weekly or less frequently, because the true maximums or minimums may not have been sampled. Extremes, when given, are provided for both the period of record and for the current water year. REVISIONS.--If errors in published water-quality records are discovered after publication, appropriate updates are made to the Water-Quality File in the U.S. Geological Survey's computerized data system, WATSTORE, and subsequently by monthly transfer of update transactions to the U.S. Environmental Protection Agency's STORET system. Because the usual volume of updates makes it impractical to document individual changes in the State data-report series or elsewhere, potential users of U.S. Geological Survey water-quality data are encouraged to obtain all required data from the appropriate computer file to insure the most recent updates. The surface-water-quality records for partial-record stations and miscellaneous sampling sites are published in separate tables following the table of discharge measurements at miscellaneous sites. No descriptive statements are given for these records. Each station is published with its own station number and name in the regular downstream-order sequence. 27 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Remark Codes The following remark codes may appear with the water-quality data in this report: PRINTED OUTPUT REMARK E Estimated value > Actual value is known to be greater than the value shown < Actual value is known to be less than the value shown K Results based on colony count outside the acceptance range (non-ideal colony count) L Biological organism count less than 0.5 percent (organism may be observed rather than counted) D Biological organism count equal to or greater than 15 percent (dominant) & Biological organism estimated as dominant Records of Ground-Water Levels Only ground-water level data from a basic network of observation wells are published herein. This basic network contains observation wells so located that the most significant data are obtained from the fewest wells in the most important aquifers. Data Collection and Computation Measurements of water levels are made in many types of wells under varying conditions, but the methods of measurement are standardized to the extent possible. The equipment and measuring techniques used at each observation well ensure that measurements at each well are of consistent accuracy and reliability. Each well is identified by means of (1) a 15-digit number that is based on latitude and longitude and (2) a local number that is provided for easy reference. See figure 10. Water-level records are obtained from direct measurements with a steel tape or from the graph or punched tape of a water- stage recorder. The water-level measurements in this report are given in feet with reference to land-surface datum (lsd). Land- surface datum is a datum plane that is approximately at land surface at each well. If known, the elevation of the land-surface datum is given in the well description. The height of the measuring point (MP) above or below land-surface datum is given in each well description. Water levels in wells equipped with recording gages are reported for every day and as an instantaneous observation at noon. Water levels are reported to as many significant figures as can be justified by the local conditions. For example, in a measurement of a depth to water of several hundred feet, the error of determining the absolute value of the total depth to water may be a few tenths of a foot, whereas the error in determining the net change of water level between successive measurements may be only a hundredth of a few hundredths of a foot. For lesser depths to water, the accuracy is greater. Accordingly, most measurements reported to a hundredth of a foot, but some are given to a tenth of a foot or a larger unit. 28 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Data Presentation Each well record consists of three parts, the station description, the data table of water levels observed during the water year and a graph of the water levels for the current water year and other selected period. The description of the well is presented first through use of descriptive headings preceding the tabular data. The comments to follow clarify information presented under the various headings of the well description. LOCATION.--This paragraph follows the well-identification number and reports the latitude and longitude (given in degrees, minutes, and seconds); a landline location designation; the hydrologic-unit number; the distance and direction from a geographic point of reference; and the owner's name. AQUIFER.--This entry designates by name (if a name exists) and geological age the aquifer(s) open to the well. WELL CHARACTERISTICS.--This entry describes the well in terms of depth, diameter, casing depth and/or screened interval, method of construction, use, and additional information such as casing breaks, collapsed screen, and other changes since construction. INSTRUMENTATION.--This paragraph provides information on both the frequency of measurement and the collection method used, allowing the user to better evaluate the reported water-level extremes by knowing whether they are based on weekly, monthly, or some other frequency of measurement. DATUM.--This entry describes both the measuring point and the land-surface elevation at the well. The measuring point is described physically (such as top of collar, notch in top of casing, plug in pump base and so on), and in relation to land surface (such as 1.3 ft above land-surface datum). The elevation of the land-surface datum is described in feet above (or below) sea level; it is reported with a precision depending on the method of determination. REMARKS.--This entry describes factors that may influence the water level in a well or the measurement of the water level. It should identify wells that also are water-quality observation wells, and may be used to acknowledge the assistance of local (non-Survey) observers. PERIOD OF RECORD.--This entry indicates the period for which there are published records for the well. It reports the month and year of the start of publication of water-level records by the U.S. Geological Survey and the words "to current year" if the records are to be continued into the following year. Periods for which water-level records are available, but are not published by the Geological Survey, may be noted. EXTREMES FOR PERIOD OF RECORD.--This entry contains the highest and lowest water levels of the period of published record, with respect to land-surface datum, and the dates of their occurrence. A table of water levels follows the station description for each well. Water levels are reported in feet below land-surface datum and all taped measurements of water level are listed. For wells equipped with recorders, daily values tables are published for the instantaneous water-level observation at noon. The highest and lowest water levels of the water year and their dates of occurrence are shown on a line below the table. Because all values are not published for wells with recorders, the extremes may be values that are not listed in the table. Missing records are indicated by dashes in place of the water level. A hydrograph for a selected period of record follows each water-level table. Records of Ground-Water Quality Records of ground-water quality in this type of report differ from other types of records in that for most sampling sites they consist of only one set of measurements for the water year. The quality of ground water ordinarily changes only slowly; therefore, for most general purposes one annual sampling, or only a few samples taken at infrequent intervals during the year, is sufficient. Frequent measurement of the same constituents is not necessary unless one is concerned with a particular problem, such as monitoring for trends in nitrate concentration. In the special cases where the quality of ground water may change more rapidly, more frequent measurements are made to identify the nature of the changes. 29 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Data Collection and Computation The records of ground-water quality in this report were obtained mostly as a part of special studies in specific areas. Consequently, a number of chemical analyses are presented for some counties but none are presented for others. As a result, the records for this year, by themselves, do not provide a balanced view of ground-water quality Statewide. Such a view can be attained only by considering records for this year in context with similar records obtained for these and other counties in earlier years. Most methods for collecting and analyzing water samples are described in the "U.S. Geological Survey Techniques of Water-Resources Investigations" manuals listed on a following page. The values reported in this type of report represent water- quality conditions at the time of sampling as much as possible, consistent with available sampling techniques and methods of analysis. All samples are obtained by trained personnel. The wells sampled are pumped long enough to assure that the water collected comes directly from the aquifer and has not stood for a long time in the well casing where it would have been exposed to the atmosphere and to the material, possibly metal, comprising the casings. Data Presentation The records of ground-water quality, when available, are published in a section titled QUALITY OF GROUND WATER immediately following the ground-water level records. Data for quality of ground water are listed alphabetically by County, and are identified by well number. The prime identification number for wells sampled is the 15-digit number derived from the latitude- longitude locations. No descriptive statements are given for ground-water-quality records; however, the well number, depth of well, date of sampling, and other pertinent data are given in the table containing the chemical analyses of the ground water. The REMARK codes listed for surface-water-quality records are also applicable to ground-water-quality records. ACCESS TO U.S. GEOLOGICAL SURVEY WATER DATA The U.S. Geological Survey provides near real-time stage and discharge data for many of the gaging stations equipped with the necessary telemetry and historic daily-mean and peak-flow discharge data for most current or discontinued gaging stations through the world wide web (WWW). These data may be accessed at http://water.usgs.gov Some water-quality and ground-water data also are available through the WWW. In addition, data can be provided in various machine-readable formats on magnetic tape or 3-1/2 inch floppy disk. Information about the availability of specific types of data or products, and user charges, can be obtained locally from each of the Water Resources Division District Offices (see address on the back of the title page). 30 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 DEFINITION OF TERMS Terms related to streamflow, water-quality, and other hydrologic data, as used in this report, are defined below. See also table for converting English units to International System (SI) Units on the inside of the back cover. Acid neutralizing capacity (ANC) is the equivalent sum of all bases or base-producing materials, solutes plus particulates, in an aqueous system that can be titrated with acid to an equivalence point. This term designates titration of an “unfiltered” sample (formerly reported as alkalinity). Acre-foot (AC-FT, acre-ft) is the quantity of water required to cover 1 acre to a depth of 1 foot and is equivalent to 43,560 cubic feet, 325,851 gallons, or 1,233 cubic meters. Adenosine triphosphate (ATP) is an organic, phosphate-rich, compound important in the transfer of energy in organisms. Its central role in living cells makes it an excellent indicator of the presence of living material in water. A measurement of ATP therefore provides a sensitive and rapid estimate of biomass. ATP is reported in micrograms per liter. Algae are mostly aquatic single-celled, colonial, or multicelled plants containing chlorophyll and lacking roots, stems, and leaves. Algal growth potential (AGP) is the maximum algal dry weight biomass that can be produced in a natural water sample under standardized laboratory conditions. The growth potential is the algal biomass present at stationary phase and is expressed as milligrams dry weight of algae produced per liter of sample. Alkalinity is the capacity of solutes in an aqueous system to neutralize acid. This term designates titration of a “filtered” sample. Annual runoff is the total quantity of water in runoff for a drainage area for the year. Data reports may use any of the following units of measurement in presenting annual runoff data: Acre-foot (AC-FT, acre-ft) is the quantity of water required to cover 1 acre to a depth of 1 foot and is equal to 43,560 cubic feet, 325,851 gallons, or 1,233 cubic meters Cubic foot per second per square mile [CFSM, (ft3/s)/mi2] is the average number of cubic feet of water flowing per second from each square mile of area drained, assuming the runoff is distributed uniformly in time and area. Inch (IN., in.) as used in this report, refers to the depth to which the drainage area would be covered with water if all of the runoff for a given time period were uniformly distributed on it. Aroclor is the registered trademark for a group of polychlorinated biphenyls that were manufactured by the Monsanto Company prior to 1976. Aroclors are assigned specific 4-digit reference numbers dependent upon molecular type and degree of substitution of the biphenyl ring hydrogen atoms by chlorine atoms. The first two digits of a numbered aroclor represent the molecular type and the last two digits represent the weight percent of the hydrogen substituted chlorine. Bacteria are microscopic unicellular organisms, typically spherical, rodlike, or spiral and threadlike in shape, often clumped into colonies. Some bacteria cause disease, while others perform an essential role in nature in the recycling of materials; for example, by decomposing organic matter into a form available for reuse by plants. Total coliform bacteria are a particular group of bacteria that are used as indicators of possible sewage pollution. This group includes coliforms that inhabit the intestine of warm-blooded animals and those that inhabit soils. They are characterized as aerobic or facultative anaerobic, gram-negative, nonspore-forming, rod-shaped bacteria that ferment lactose with gas formation within 48 hours at 35 °C. In the laboratory, these bacteria are defined as all the organisms that produce colonies with a golden-green metallic sheen within 24 hours when incubated at 35 °C plus or minus 1.0 °C on M-Endo medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. Fecal coliform bacteria are bacteria that are present in the intestine or feces of warm-blooded animals. They are often used as indicators of the sanitary quality of the water. In the laboratory, they are defined as all organisms that produce blue colonies within 24 hours when incubated at 44.5 °C plus or minus 0.2 °C on M-FC medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. Fecal streptococcal bacteria are bacteria found in the intestine of warm-blooded animals. Their presence in water is considered to verify fecal pollution. They are characterized as gram-positive, cocci bacteria that are capable of growth in brain-heart infusion broth. In the laboratory, they are defined as all the organisms that produce red or pink colonies within 48 hours at 35 °C plus or minus 1.0 °C on KF-streptococcus medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. 31 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Enterococcus bacteria are commonly found in the feces of humans and other warm-blooded animals. Although some strains are ubiquitous and not related to fecal pollution, the presence of enterococci in water is an indication of fecal pollution and the possible presence of enteric pathogens. Enterococcus bacteria are those bacteria that produce pink to red colonies with black or reddish-brown precipitate after incubation at 41 °C on mE agar and subsequent transfer to EIA medium. Enterococci include Streptococcus feacalis, Streptococcus feacium, Streptococcus avium, and their variants. Escherichia coli (E. coli) are bacteria present in the intestine and feces of warm-blooded animals. E. coli are a member species of the fecal coliform group of indicator bacteria. In the laboratory, they are defined as those bacteria that produce yellow or yellow-brown colonies on a filter pad saturated with urea substrate broth after primary culturing for 22 to 24 hours at 44.5 ˚C on mTEC medium. Their concentrations are expressed as number of colonies per 100 mL of sample. Base flow is flow in a channel sustained by ground-water discharge in the absence of direct runoff. Bed material is the sediment mixture of which a streambed, lake, pond, reservoir, or estuary bottom is composed. Benthic organisms (invertebrates) are the group of animals inhabiting the bottom of an aquatic environment. They include a number of types of organisms, such as bacteria, fungi, insect larvae and nymphs, snails, clams, and crayfish. They are useful as indicators of water quality. Biochemical oxygen demand (BOD) is a measure of the quantity of dissolved oxygen, in milligrams per liter, necessary for the decomposition of organic matter by microorganisms, such as bacteria. Biomass is the amount of living matter present at any given time, expressed as mass per unit area or volume of habitat. Ash mass is the mass or amount of residue present after the residue from the dry mass determination has been ashed in a muffle furnace at a temperature of 500 °C for 1 hour. Ash mass of zooplankton and phytoplankton is expressed in grams per cubic meter (g/m3), and periphyton and benthic organisms in grams per square meter (g/m2). Dry mass refers to the mass of residue present after drying in an oven at 105 °C for zooplankton and periphyton, until the mass remains unchanged. This mass represents the total organic matter, ash, and sediment in the sample. Dry mass is expressed in the same units as ash mass. Organic mass or volatile mass of the living substance is the difference between the dry mass and ash mass and represents the actual mass of the living matter. Organic mass is expressed in the same units as for ash mass and dry mass. Wet mass is the mass of living matter plus contained water. Biomass pigment ratio is an indicator of the total proportion of periphyton which are autotrophic (plants). This is also called the Autotrophic Index. Bottom material: See “Bed material.” Cells/volume refers to the number of plankton cells or natural units counted using a microscope and grid or counting cell. Results are generally reported as cells or units per milliliter. Cells volume (biovolume) determination is one of several common methods used to estimate biomass of algae in aquatic systems. Cell members of algae are frequently used in aquatic surveys as an indicator of algal production. However, cell numbers alone cannot represent true biomass because of considerable cell-size variation among the algal species. Cell volume (µm3) is determined by obtaining critical cell measurements on cell dimensions (for example, length, width, height, or radius) for 20 to 50 cells of each important species to obtain an average biovolume per cell. Cells are categorized according to the correspondence of their cellular shape to the nearest geometric solid or combinations of simple solids (for example, spheres, cones, or cylinders). Representative formulae used to compute biovolume are as follows: sphere 4/3 πr3 cone 1/3 πr3h cylinder πr3h. From cell volume, total algal biomass expressed as biovolume (µm3/mL) is thus determined by multiplying the number of cells of a given species by its average cell volume and then summing these volumes over all species. Chemical oxygen demand (COD) is a measure of the chemically oxidizable material in the water and furnishes an approximation of the amount of organic and reducing material present. The determined value may correlate with BOD or with carbonaceous organic pollution from sewage or industrial wastes. 32 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Chlorophyll refers to the green pigments of plants. Chlorophyll a and b are the two most common green pigments in plants. Colloid is any substance with particles in such a fine state of subdivision dispersed in a medium (for example, water) that they do not settle out; but not in so fine a state of subdivision that they can be said to be truly dissolved. Color unit is produced by 1 milligram per liter of platinum in the form of the chloroplatinate ion. Color is expressed in units of the platinum-cobalt scale. Confined aquifer is a term used to describe an aquifer containing water between two relatively impermeable boundaries. The water level in a well tapping a confined aquifer stands above the top of the confined aquifer and can be higher or lower than the water table that may be present in the material above it. In some cases the water level can rise above the ground surface, yielding a flowing well. Contents is the volume of water in a reservoir or lake. Unless otherwise indicated, volume is computed on the basis of a level pool and does not include bank storage. Continuous-record station is a site that meets either of the following conditions: 1.Stage or streamflow are recorded at some interval on a continuous basis. The recording interval is usually 15 minutes, but may be less or more frequent. 2.Water-quality, sediment, or other hydrologic measure-ments are recorded at least daily. Control designates a feature in the channel downstream from a gaging station that physically influences the water-surface elevation and thereby determines the stage-discharge relation at the station. This feature may be a constriction of the channel, a bedrock outcrop, a gravel bar, an artificial structure, or a uniform cross section over a long reach of the channel. Control structure as used in this report is a structure on a stream or canal that is used to regulate the flow or stage of the stream or to prevent the intrusion of saltwater. Cubic foot per second (CFS, ft3/s) is the rate of discharge representing a volume of 1 cubic foot passing a given point in 1 second. It is equivalent to approximately 7.48 gallons per second, 448.8 gallons per minute, or 0.02832 cubic meters per second. Cubic foot per second-day (CFS-DAY, Cfs-day, [(ft3/s)/d]) is the volume of water represented by a flow of 1 cubic foot per second for 24 hours. It is equivalent to 86,400 cubic feet, 1.9835 acre-feet, 646,317 gallons, or 2,447 cubic meters. Daily record is a summary of streamflow, sediment, or water-quality values computed from data collected with sufficient frequency to obtain reliable estimates of daily mean values. Daily record station is a site for which daily records of streamflow, sediment, or water-quality values are computed. Datum, as used in this report, is an elevation above mean sea level to which all gage height readings are referenced. Diel is of or pertaining to a 24-hour period of time; a regular daily cycle. Discharge, or flow, is the volume of water (or more broadly, volume of fluid including solid- and dissolved-phase material), that passes a given point in a given period of time. Annual 7-day minimum is the lowest mean discharge for 7 consecutive days in a year. Note that most low-flow frequency analyses of annual 7-day minimum flows use a climatic year (April 1-March 31). The date shown in the summary statistics table is the initial date of the 7-day period. (This value should not be confused with the 7-day 10-year low-flow statistic.) Instantaneous discharge is the discharge at a particular instant of time. Mean discharge (MEAN) is the arithmetic mean of individual daily mean discharges during a specific period. Dissolved refers to that material in a representative water sample that passes through a 0.45-micrometer membrane filter. This is a convenient operational definition used by Federal agencies that collect water data. Determinations of “dissolved” constituents are made on subsamples of the filtrate. 33 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Dissolved oxygen (DO) content of water in equilibrium with air is a function of atmospheric pressure, temperature, and dissolved-solids concentration of the water. The ability of water to retain oxygen decreases with increasing temperature or dissolved solids, with small temperature changes having the more significant offset. Photosynthesis and respiration may cause diurnal variations in dissolved-oxygen concentration in water from some streams. Dissolved-solids concentration of water is determined either analytically by the “residue-on-evaporation” method, or mathematically by totaling the concentrations of individual constituents reported in a comprehensive chemical analysis. During that analytical determination of dissolved solids, the bicarbonate (generally a major dissolved component of water) is converted to carbonate. Therefore, in the mathematical calculation of dissolved-solids concentration, the bicarbonate value, in milligrams per liter, is multiplied by 0.4926 to reflect the change. Alternatively, alkalinity concentration (as mg/L CaCO3) can be converted to carbonate concentration by multiplying by 0.60. Diversity index is a numerical expression of evenness of distribution of aquatic organisms. The formula for diversity index is: where ni is the number of individuals per taxon, n is the total number of individuals, and s is the total number of taxa in the sample of the community. Diversity index values range from zero, when all the organisms in the sample are the same, to some positive number, when some or all of the organisms in the sample are different. Drainage area of a site on a stream is that area, measured in a horizontal plane, that has a common outlet at the site for its surface runoff. Figures of drainage area given herein include all closed basins, or noncontributing areas, within the area unless otherwise specified. Drainage basin is a part of the Earth’s surface that is occupied by a drainage system with a common outlet for its surface runoff (see “Drainage area”). Dry weight refers to the weight of animal tissue after it has been dried in an oven at 65 ˚C until a constant weight is achieved. Dry weight represents total organic and inorganic matter in the tissue. Flow-duration percentiles are values on a scale of 100 that indicate the percentage of time for which a flow is not exceeded. For example, the 90th percentile of river flow is greater than or equal to 90 percent of all recorded flow rates. Gage datum is the elevation of the zero point of the reference gage from which gage height is determined as compared to sea level (see “Datum”). This elevation is established by a system of levels from known benchmarks, by approximation from topographic maps, or by geographical positioning system. Gage height (G.H.) is the water-surface elevation referenced to the gage datum. Gage height is often used interchangeably with the more general term “stage,” although gage height is more appropriate when used with a reading on a gage. Gaging station is a site on a stream, canal, lake, or reservoir where systematic observations of stage, discharge, or other hydrologic data are obtained. When used in connection with a discharge record, the term is applied only to those gaging stations where a continuous record of discharge is computed. Gas chromatography/flame ionization detector (GC/FID) is a laboratory analytical method used as a screening technique for semivolatile organic compounds that are extractable from water in methylene chloride . Ground-water level is the elevation of the water table or another potentiometric surface at a particular location. Hardness of water is a physical-chemical characteristic that is commonly recognized by the increased quantity of soap required to produce lather. It is attributable to the presence of alkaline earths (principally calcium and magnesium) and is expressed as the equivalent concentration of calcium carbonate (CaCO3). High tide is the maximum height reached by each rising tide. The high-high and low-high tides are the higher and lower of the two high tides, respectively, of each tidal day. See NOAA web site: http://www.co-ops.nos.noaa.gov/tideglos.html Hydrologic benchmark station is one that provides hydrologic data for a basin in which the hydrologic regimen will likely be governed solely by natural conditions. Data collected at a benchmark station may be used to separate effects of natural from human-induced changes in other basins that have been developed and in which the physiography, climate, and geology are similar to those in the undeveloped benchmark basin. d ni n--- i 1 ≈ s ∑ ni n--- 2 log – = 34 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Hydrologic unit is a geographic area representing part or all of a surface drainage basin or distinct hydrologic feature as defined by the former Office of Water Data Coordination and delineated on the State Hydrologic Unit Maps by the U.S. Geological Survey. Each hydrologic unit is identified by an 8-digit number. Land-surface datum (lsd) is a datum plane that is approximately at land surface at each ground-water observation well . Light-attenuation coefficient, also known as the extinction coefficient, is a measure of water clarity. Light is attenuated according to the Lambert-Beer equation where Io is the source light intensity, I is the light intensity at length L (in meters) from the source, λ is the light-attenuation coefficient, and e is the base of the natural logarithm. The light attenuation coefficient is defined as Lipid is any one of a family of compounds that are insoluble in water and that make up one of the principal components of living cells. Lipids include fats, oils, waxes, and steroids. Many environmental contaminants such as organochlorine pesticides are lipophilic. Low tide is the minimum height reached by each falling tide. The high-low and low-low tides are the higher and lower of the two low tides, respectively, of each tidal day. See NOAA web site: http://www.co-ops.nos.noaa.gov/tideglos.html Macrophytes are the macroscopic plants in the aquatic environment. The most common macrophytes are the rooted vascular plants that are usually arranged in zones in aquatic ecosystems and restricted in the area by the extent of illumination through the water and sediment deposition along the shoreline. Measuring point (MP) is an arbitrary permanent reference point from which the distance to water surface in a well is measured to obtain water level. Membrane filter is a thin microporous material of specific pore size used to filter bacteria, algae, and other very small particles from water. Metamorphic stage refers to the stage of development that an organism exhibits during its transformation from an immature form to an adult form. This developmental process exists for most insects, and the degree of difference from the immature stage to the adult form varies from relatively slight to pronounced, with many intermediates. Examples of metamorphic stages of insects are egg-larva-adult or egg-nymph-adult. Methylene blue active substances (MBAS) are apparent detergents. The determination depends on the formation of a blue color when methylene blue dye reacts with synthetic anionic detergent compounds. Micrograms per gram (UG/G, µg/g) is a unit expressing the concentration of a chemical constituent as the mass (micrograms) of the element per unit mass (gram) of material analyzed. Micrograms per kilogram (UG/KG, µg/kg) is a unit expressing the concentration of a chemical constituent as the mass (micrograms) of the constituent per unit mass (kilogram) of the material analyzed. One microgram per kilogram is equivalent to 1 part per billion. Micrograms per liter (UG/L, µg/L) is a unit expressing the concentration of chemical constituents in water as mass (micrograms) of constituent per unit volume (liter) of water. One thousand micrograms per liter is equivalent to 1 milligram per liter. Microsiemens per centimeter (US/CM, µS/cm) is a unit expressing the amount of electrical conductivity of a solution as measured between opposite faces of a centimeter cube of solution at a specified temperature. Siemens is the International System of Units nomenclature. It is synonymous with mhos and is the reciprocal of resistance in ohms. Milligrams per liter (MG/L, mg/L) is a unit for expressing the concentration of chemical constituents in water as the mass (milligrams) of constituent per unit volume (liter) of water. Concentration of suspended sediment also is expressed in mg/L and is based on the mass of dry sediment per liter of water-sediment mixture. I Ioe λL – = λ 1 L-- e log I Io ---- – = 35 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Miscellaneous site, or miscellaneous station, is a site where streamflow, sediment, and/or water-quality data are collected once, or more often on a random or discontinuous basis. Most probable number (MPN) is an index of the number of coliform bacteria that, more probably than any other number, would give the results shown by the laboratory examination; it is not an actual enumeration. MPN is determined from the distribution of gas-positive cultures among multiple inoculated tubes. Multiple-plate samplers are artificial substrates of known surface area used for obtaining benthic invertebrate samples. They consist of a series of spaced, hardboard plates on an eyebolt. Nanograms per liter (NG/L, ng/L) is a unit expressing the concentration of chemical constituents in solution as mass (nanograms) of solute per unit volume (liter) of water. One million nanograms per liter is equivalent to 1 milligram per liter. National Geodetic Vertical Datum of 1929 (NGVD of 1929) is a geodetic datum derived from a general adjustment of the first order level nets of the United States and Canada. It was formerly called “Sea Level Datum of 1929” or “mean sea level” in this series of reports. Although the datum was derived from the average sea level over a period of many years at 26 tide stations along the Atlantic, Gulf of Mexico, and Pacific Coasts, it does not necessarily represent local mean sea level at any particular place. See NOAA web site: http://www.ngs.noaa.gov/faq.shtml#WhatVD29VD88 Nekton are the consumers in the aquatic environment and consist of large free-swimming organisms that are capable of sustained, directed mobility. Nephelometric turbidity unit (NTU) is the measurement for reporting turbidity that is based on use of a standard suspension of Formazin. Turbidity measured in NTU uses nephelometric methods that depend on passing specific light of a specific wavelength through the sample. Open or screened interval is the length of unscreened opening or of well screen through which water enters a well, in feet below land surface. Organic carbon (OC) is a measure of organic matter present in aqueous solution, suspension, or bottom sediments. May be reported as dissolved organic carbon (DOC), suspended organic carbon (SOC), or total organic carbon (TOC). Organism is any living entity. Organism count/area refers to the number of organisms collected and enumerated in a sample and adjusted to the number per area habitat, usually square meter (m2), acre, or hectare. Periphyton, benthic organisms, and macrophytes are expressed in these terms. Organism count/volume refers to the number of organisms collected and enumerated in a sample and adjusted to the number per sample volume, usually milliliter (mL) or liter (L). Numbers of planktonic organisms can be expressed in these terms. Total organism count is the total number of organisms collected and enumerated in any particular sample. Organochlorine compounds are any chemicals that contain carbon and chlorine. Organochlorine compounds that are important in investigations of water, sediment, and biological quality include certain pesticides and industrial compounds. Parameter Code is a 5-digit number used in the U.S. Geological Survey computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property. Partial-record station is a site where discrete measurements of one or more hydrologic parameters are obtained over a period of time without continuous data being recorded or computed. A common example is a crest-stage gage partial-record station at which only peak stages and flows are recorded. Particle size is the diameter, in millimeters (mm), of a particle determined by sieve or sedimentation methods. The sedimentation method utilizes the principle of Stokes Law to calculate sediment particle sizes. Sedimentation methods (pipet, bottom-withdrawal tube, visual-accumulation tube, Sedigraph) determine fall diameter of particles in either distilled water (chemically dispersed) or in native water (the river water at the time and point of sampling). 36 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Particle-size classification used in this report agrees with the recommendation made by the American Geophysical Union Subcommittee on Sediment Terminology. The classification is as follows: The particle-size distributions given in this report are not necessarily representative of all particles in transport in the stream. Most of the organic matter is removed, and the sample is subjected to mechanical and chemical dispersion before analysis in distilled water. Chemical dispersion is not used for native water analysis. ____________________________________________________ Classification Size (mm) Method of analysis ____________________________________________________ Clay 0.00024 - 0.004 Sedimentation Silt 0.004 - 0.062 Sedimentation Sand 0.062 - 2.0 Sedimentation/sieve Gravel 2.0 - 64.0 Sieve ____________________________________________________ Percent composition or percent of total is a unit for expressing the ratio of a particular part of a sample or population to the total sample or population, in terms of types, numbers, weight, or volume. Periodic station is a site where stage, discharge, sediment, chemical, or other hydrologic measurements are made one or more times during a year, but at a frequency insufficient to develop a daily record. Periphyton is the assemblage of microorganisms attached to and living upon submerged solid surfaces. While primarily consisting of algae, they also include bacteria, fungi, protozoa, rotifers, and other small organisms. Periphyton are useful indicators of water quality. Pesticides are chemical compounds used to control undesirable organisms. Major categories of pesticides include insecticides, miticides, fungicides, herbicides, and rodenticides. pH of water is the negative logarithm of the hydrogen-ion activity. Solutions with pH less than 7 are termed “acidic,” and solutions with a pH greater than 7 are termed “basic.” Solutions with a pH of 7 are neutral. The presence and concentration of many dissolved chemical constituents found in water are, in part, influenced by the hydrogen-ion activity of water. Biological processes including growth, distribution of organisms, and toxicity of the water to organisms are also influenced, in part, by the hydrogen-ion activity of water . Picocurie (PC, pCi) is one trillionth (1 x 10-12) of the amount of radioactivity represented by a curie (Ci). A curie is the amount of radioactivity that yields 3.7 x 1010 radioactive disintegrations per second. A picocurie yields 2.22 dpm (disintegrations per minute). Plankton is the community of suspended, floating, or weakly swimming organisms that live in the open water of lakes and rivers. Concentrations are expressed as a number of cells per milliliter (cells/mL of sample). Phytoplankton is the plant part of the plankton. They are usually microscopic, and their movement is subject to the water currents. Phytoplankton growth is dependent upon solar radiation and nutrient substances. Because they are able to incorporate as well as release materials to the surrounding water, the phytoplankton have a profound effect upon the quality of the water. They are the primary food producers in the aquatic environment and are commonly known as algae. Blue-green algae (Cyanophyta) are a group of phytoplankton organisms having a blue pigment, in addition to the green pigment called chlorophyll. Blue-green algae often cause nuisance conditions in water. Diatoms are the unicellular or colonial algae having a siliceous shell. Their concentrations are expressed as number of cells per milliliter (cells/mL) of sample. Euglenoids (Euglenophyta) are a group of algae that are usually free-swimming and rarely creeping. They have the ability to grow either photosynthetically in the light or heterotrophically in the dark. Fire algae (Pyrrhophyta) are a group of algae that are free-swimming unicells characterized by a red pigment spot. Green algae have chlorophyll pigments similar in color to those of higher green plants. Some forms produce algae mats or floating “moss” in lakes. Their concentrations are expressed as number of cells per milliliter (cells/mL) of sample. 37 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Zooplankton is the animal part of the plankton. Zooplankton are capable of extensive movements within the water column and are often large enough to be seen with the unaided eye. Zooplankton are secondary consumers feeding upon bacteria, phytoplankton, and detritus. Because they are the grazers in the aquatic environment, the zooplankton are a vital part of the aquatic food web. The zooplankton community is dominated by small crustaceans and rotifers. Polychlorinated biphenyls (PCB’s) are industrial chemicals that are mixtures of chlorinated biphenyl compounds having various percentages of chlorine. They are similar in structure to organochlorine insecticides. Polychlorinated naphthalenes (PCN’s) are industrial chemicals that are mixtures of chlorinated naphthalene compounds. They have properties and applications similar to polychlorinated biphenyls (PCB’s) and have been identified in commercial PCB preparations. Primary productivity is a measure of the rate at which new organic matter is formed and accumulated through photosynthetic and chemosynthetic activity of producer organisms (chiefly, green plants). The rate of primary production is estimated by measuring the amount of oxygen released (oxygen method) or the amount of carbon assimilated (carbon method) by the plants. Primary productivity (carbon method) is expressed as milligrams of carbon per area per unit time [mg C/(m2/ time)] for periphyton and macrophytes or per volume [mg C/(m3/time)] for phytoplankton. Carbon method defines the amount of carbon dioxide consumed as measured by radioactive carbon (carbon-14). The carbon-14 method is of greater sensitivity than the oxygen light and dark bottle method and is preferred for use in unenriched waters. Unit time may be either the hour or day, depending on the incubation period. Primary productivity (oxygen method) is expressed as milligrams of oxygen per area per unit time [mg O/(m2/ time)] for periphyton and macrophytes or per volume [mg O/(m3/time)] for phytoplankton. Oxygen method defines production and respiration rates as estimated from changes in the measured dissolved-oxygen concentration. The oxygen light and dark bottle method is preferred if the rate of primary production is sufficient for accurate measurements to be made within 24 hours. Unit time may be either the hour or day, depending on the incubation period. Radioisotopes are isotopic forms of an element that exhibit radioactivity. Isotopes are varieties of a chemical element that differ in atomic weight, but are very nearly alike in chemical properties. The difference arises because the atoms of the isotopic forms of an element differ in the number of neutrons in the nucleus; for example, ordinary chlorine is a mixture of isotopes having atomic weights of 35 and 37, and the natural mixture has an atomic weight of about 35.453. Many of the elements similarly exist as mixtures of isotopes, and a great many new isotopes have been produced in the operation of nuclear devices such as the cyclotron. There are 275 isotopes of the 81 stable elements, in addition to more than 800 radioactive isotopes. Recoverable from bottom material is the amount of a given constituent that is in solution after a representative sample of bottom material has been digested by a method (usually using an acid or mixture of acids) that results in dissolution of readily soluble substances. Complete dissolution of all bottom material is not achieved by the digestion treatment and thus the determination represents less than the total amount (that is, less than 95 percent) of the constituent in the sample. To achieve comparability of analytical data, equivalent digestion procedures would be required of all laboratories performing such analyses because different digestion procedures are likely to produce different analytical results. Recurrence interval, also referred to as return period, is the average time, usually expressed in years, between occurrences of hydrologic events of a specified type (such as exceedances of a specified high flow or non-exceedance of a specified low flow). The terms “return period” and “recurrence interval” do not imply regular cyclic occurrence. The actual times between occurrences vary randomly, with most of the times being less than the average and a few being substantially greater than the average. For example, the 100-year flood is the flow rate that is exceeded by the annual maximum peak flow at intervals whose average length is 100 years (that is, once in 100 years, on average); almost two-thirds of all exceedances of the 100-year flood occur less than 100 years after the previous exceedance, half occur less than 70 years after the previous exceedance, and about one-eighth occur more than 200 years after the previous exceedance. Similarly, the 7-day 10-year low flow (7Q10) is the flow rate below which the annual minimum 7-day-mean flow dips at intervals whose average length is 10 years (that is, once in 10 years, on average); almost two- thirds of the non-exceedances of the 7Q10 occur less than 10 years after the previous non-exceedance, half occur less than 7 years after, and about one-eighth occur more than 20 years after the previous non-exceedance. The recurrence interval for annual events is the reciprocal of the annual probability of occurrence. Thus, the 100-year flood has a 1-percent chance of being exceeded by the maximum peak flow in any year, and there is a 10-percent chance in any year that the annual minimum 7-day-mean flow will be less than the 7Q10. Replicate samples are a group of samples collected in a manner such that the samples are thought to be essentially identical in composition. River mile is the distance of a point on a river measured in miles from the river’s mouth along the low-water channel. 38 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 River mileage is the linear distance along the meandering path of a stream channel determined in accordance with Bulletin No. 14 (October 1968) of the Water Resources Council. Runoff in inches (IN., in.) is the depth, in inches, to which the drainage area would be covered if all the runoff for a given time period were uniformly distributed on it. Sea level refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929)—a geodetic datum derived from a general adjustment of the first-order level nets of the United States and Canada, formerly called Sea Level Datum of 1929. See: http://www.co-ops.nos.noaa.gov/ glossary/gloss_n.html#NGVD Sediment is solid material that is transported by, suspended in, or deposited from water. It originates mostly from disintegrated rocks; it also includes chemical and biochemical precipitates and decomposed organic material, such as humus. The quantity, characteristics, and cause of the occurrence of sediment in streams are influenced by environmental factors. Some major factors are degree of slope, length of slope, soil characteristics, land usage, and quantity and intensity of precipitation. Bed load is the sediment that is transported in a stream by rolling, sliding, or skipping along or very close to the bed. In this report, bed load is considered to consist of particles in transit from the bed to an elevation equal to the top of the bed-load sampler nozzle (usually within 0.25 ft of the streambed). Bed-load discharge (tons per day) is the quantity of sediment moving as bed load, reported as dry weight, that passes a cross section in a given time. Suspended sediment is the sediment that is maintained in suspension by the upward components of turbulent currents or that exists in suspension as a colloid. Suspended-sediment concentration is the velocity-weighted concentration of suspended sediment in the sampled zone (from the water surface to a point approximately 0.3 ft above the bed) expressed as milligrams of dry sediment per liter of water-sediment mixture (mg/L). The entire sample is used for the analysis. Mean concentration of suspended sediment is the time-weighted concentration of suspended sediment passing a stream section during a 24-hour day. Suspended-sediment discharge (tons/day) is the quantity of sediment moving in suspension, reported as dry weight, that passes a cross section in a given time. It is calculated in units of tons per day as follows: concentration (mg/ L) x discharge (ft3/s) x 0.0027. Suspended-sediment load is a term that refers to material in suspension. The term needs to be qualified, such as “annual suspended-sediment load” or “sand-size suspended-sediment load,” and so on. It is not synonymous with either suspended-sediment discharge or concentration. Total sediment discharge (tons/day) is the sum of the suspended-sediment discharge and the bed-load discharge. It is the total quantity of sediment, reported as dry weight, that passes a cross section in a given time. Total sediment load or total load is a term that refers to the total sediment (bed load plus suspended-sediment load) that is in transport. The term needs to be qualified, such as “annual suspended-sediment load” or “sand-size suspended-sediment load,” and so on. It is not synonymous with total sediment discharge. Seven-day 10-year low flow (7Q10, 7Q10) is the minimum flow averaged over 7 consecutive days that is expected to occur on average, once in any 10-year period. The 7Q10 has a 10-percent chance of occurring in any given year. Sodium adsorption ratio (SAR) is the expression of relative activity of sodium ions in exchange reactions within soil and is an index of sodium or alkali hazard to the soil. Waters range in respect to sodium hazard from those which can be used for irrigation on almost all soils to those which are generally unsatisfactory for irrigation. Solute is any substance that is dissolved in water. Specific conductance is a measure of the ability of a water to conduct an electrical current. It is expressed in microsiemens per centimeter at 25 °C. Specific conductance is related to the type and concentration of ions in solution and can be used for approximating the dissolved-solids content of the water. Commonly, the concentration of dissolved solids (in milligrams per liter) is from 55 to 75 percent of the specific conductance (in microsiemens). This relation is not constant from stream to stream, and it may vary in the same source with changes in the composition of the water. 39 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Stable isotope ratio (per MILL/MIL) is a unit expressing the ratio of the abundance of two radioactive isotopes. Isotope ratios are used in hydrologic studies to determine the age or source of specific waters, to evaluate mixing of different waters, as an aid in determining reaction rates, and other chemical or hydrologic processes. Stage: See “Gage height.” Stage-discharge relation is the relation between the water-surface elevation, termed stage (gage height), and the volume of water flowing in a channel per unit time. Streamflow is the discharge that occurs in a natural channel. Although the term “discharge” can be applied to the flow of a canal, the word “streamflow” uniquely describes the discharge in a surface stream course. The term “streamflow” is more general than “runoff” as streamflow may be applied to discharge whether or not it is affected by diversion or regulation. Substrate is the physical surface upon which an organism lives. Artificial substrate is a device which is purposely placed in a stream or lake for colonization of organisms. The artificial substrate simplifies the community structure by standardizing the substrate from which each sample is taken. Examples of artificial substrates are basket samplers (made of wire cages filled with clean streamside rocks) and multiplate samplers (made of hardboard) for benthic organism collection, and plexiglass strips for periphyton collection. Natural substrate refers to any naturally occurring immersed or submersed solid surface, such as a rock or tree, upon which an organism lives. Surface area of a lake or impoundment is that area encompassed by the boundary of the lake or impoundment as shown on USGS topographic maps, or on other available maps or photographs. The computed surface areas reflect the water levels of the lakes or impoundments at the times when the information for the maps or photographs was obtained. Surficial bed material is the top 0.1 to 0.2 ft of the bed material that is sampled using U.S. Series Bed-Material Samplers. Suspended (as used in tables of chemical analyses) refers to the amount (concentration) of undissolved material in a water-sediment mixture. It is associated with the material retained on a 0.45-micrometer filter. Suspended, recoverable is the amount of a given constituent that is in solution after the part of a representative suspended-sediment sample that is retained on a 0.45-micrometer membrane filter has been digested by a method (usually using a dilute acid solution) that results in dissolution of only readily soluble substances. Complete dissolution of all the particulate matter is not achieved by the digestion treatment and thus the determination represents something less than the “total” amount (that is, less than 95 percent) of the constituent present in the sample. To achieve comparability of analytical data, equivalent digestion procedures are required of all laboratories performing such analyses because different digestion procedures are likely to produce different analytical results. Determinations of “suspended, recoverable” constituents are made either by analyzing portions of the material collected on the filter or, more commonly, by difference, based on determinations of (1) dissolved and (2) total recoverable concentrations of the constituent. Suspended, total is the total amount of a given constituent in the part of a representative suspended-sediment sample that is retained on a 0.45-micrometer membrane filter. This term is used only when the analytical procedure assures measurement of at least 95 percent of the constituent determined. Knowledge of the expected form of the constituent in the sample, as well as the analytical methodology used, is required to determine when the results should be reported as “suspended, total.” Determinations of “suspended, total” constituents are made either by analyzing portions of the material collected on the filter or, more commonly, by difference, based on determinations of (1) dissolved and (2) total concentrations of the constituent. Synoptic Studies are short-term investigations of specific water-quality conditions during selected seasonal or hydrologic periods to provide improved spatial resolution for critical water-quality conditions. For the period and conditions sampled, they assess the spatial distribution of selected water-quality conditions in relation to causative factors, such as land use and contaminant sources. 40 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Taxonomy is the division of biology concerned with the classification and naming of organisms. The classification of organisms is based upon a hierarchial scheme beginning with Kingdom and ending with Species at the base. The higher the classification level, the fewer features the organisms have in common. For example, the taxonomy of a particular mayfly, Hexagenia limbata, is the following: Kingdom Animal Phylum Arthropoda ClassI insecta Order Ephemeroptera Family Ephemeridae Genus Hexagenia Species Hexagenia limbata Time-weighted average is computed by multiplying the number of days in the sampling period by the concentrations of individual constituents for the corresponding period and dividing the sum of the products by the total number of days. A time- weighted average represents the composition of water that would be contained in a vessel or reservoir that had received equal quantities of water from the stream each day for the year. Tons per acre-foot is the dry mass of dissolved solids in 1 acre-foot of water. It is computed by multiplying the concentration of the constituent, in milligrams per liter, by 0.00136. Tons per day (T/DAY, tons/d) is the rate representing a mass of 1 ton of a constituent in streamflow passing a cross section in 1 day. It is equivalent to 2,000 pounds per day, or 0.9072 metric tons per day. Total is the total amount of a given constituent in a representative suspended-sediment sample, regardless of the constituent’s physical or chemical form. This term is used only when the analytical procedure assures measurement of at least 95 percent of the constituent present in both the dissolved and suspended phases of the sample. A knowledge of the expected form of the constituent in the sample, as well as the analytical methodology used, is required to judge when the results should be reported as “total.” (Note that the word “total” does double duty here, indicating both that the sample consists of a suspended-sediment mixture and that the analytical method determined all of the constituent in the sample.) Total discharge is the quantity of a given constituent, measured as dry mass or volume, that passes a stream cross section per unit of time. When referring to constituents other than water, this term needs to be qualified, such as “total sediment discharge,” “total chloride discharge,” and so on. Total in bottom material is the total amount of a given constituent in a representative sample of bottom material. This term is used only when the analytical procedure assures measurement of at least 95 percent of the constituent determined. A knowledge of the expected form of the constituent in the sample, as well as the analytical methodology used, is required to judge when the results should be reported as “total in bottom material.” Total length (fish) is the straight-line distance from the anterior point of a fish specimen’s snout, with the mouth closed, to the posterior end of the caudal (tail) fin, with the lobes of the caudal fin squeezed together. Total load refers to all of a constituent in transport. When referring to sediment, it includes suspended load plus bed load. Total recoverable is the amount of a given constituent that is in solution after a representative suspended-sediment sample has been digested by a method (usually using a dilute acid solution) that results in dissolution of only readily soluble substances. Complete dissolution of all particulate matter is not achieved by the digestion treatment, and thus the determination represents something less than the “total” amount (that is, less than 95 percent) of the constituent present in the dissolved and suspended phases of the sample. To achieve comparability of analytical data, equivalent digestion procedures are required of all laboratories performing such analyses because different digestion procedures are likely to produce different analytical results. Turbidity is a measurement of the collective optical properties of a water sample that cause light to be scattered and absorbed rather than transmitted in straight lines; the higher the intensity of scattered light, the higher the turbidity. Turbidity is expressed in nephelometric turbidity units (NTU) or Formazin turbidity units (FTU) depending on the method and equipment used. Ultraviolet (UV) absorbance (absorption) at 254 or 280 nanometers is a measure of the aggregate concentration of the mixture of UV absorbing organic materials dissolved in the analyzed water, such as lignin, tanin, humic substances, and various aromatic compounds. UV absorbance (absorption) at 254 or 280 nanometers is measured in UV absorption units per centimeter of pathlength of UV light through a sample. 41 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2000 Volatile organic compounds (VOC’s) are organic compounds that can be isolated from the water phase of a sample by purging the water sample with inert gas, such as helium, and subsequently analyzed by gas chromatography. Many VOC’s are manmade chemicals that are used and produced in the manufacture of paints, adhesives, petroleum products, pharmaceuticals, and refrigerants. They are often components of fuels, solvents, hydraulic fluids, paint thinners, and dry cleaning agents commonly used in urban settings. VOC contamination of drinking-water supplies is a human health concern because many are toxic and are known or suspected human carcinogens (U.S. Environmental Protection Agency, 1996). Water level is the water-surface elevation or stage of the free surface of a body of water above or below any datum (see “Gage height”), or the surface of water standing in a well, usually indicative of the position of the water table or other potentiometric surface. Water table is the surface of a ground-water body at which the water is at atmospheric pressure. Water-table aquifer is an unconfined aquifer within which is found the water table. Water year in U.S. Geological Survey reports dealing with surface-water supply is the 12-month period October 1 through September 30. The water year is designated by the calendar year in which it ends and which includes 9 of the 12 months. Thus, the year ending September 30, 1999, is called the “1999 water year.” WDR is used as an abbreviation for “Water-Data Report” in the REVISED RECORDS paragraph to refer to State annual hydrologic-data reports. (WRD was used as an abbreviation for “Water-Resources Data” in reports published prior to 1976.) Weighted average is used in this report to indicate discharge-weighted average. It is computed by multiplying the discharge for a sampling period by the concentrations of individual constituents for the corresponding period and dividing the sum of the products by the sum of the discharges. A discharge-weighted average approximates the composition of water that would be found in a reservoir containing all the water passing a given location during the water year after thorough mixing in the reservoir. Well is an excavation (pit, hole, tunnel), generally cylindrical in form and often walled in, drilled, dug, driven, bored, or jetted into the ground to such a depth as to penetrate water-yielding geologic material and allow the water to flow or to be pumped to the surface. Wet weight refers to the weight of animal tissue or other substance including its contained water. WSP is used as an abbreviation for “Water-Supply Paper” in reference to previously published report 42 TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS OF THE U.S. GEOLOGICAL SURVEY The U.S.G.S. publishes a series of manuals describing procedures for planning and conducting specialized work in water- resources investigations. The material is grouped under major subject headings called books and is further divided into sec- tions and chapters. For example, section A of book 3 (Applications of Hydraulics) pertains to surface water. The chapter, the unit of publication, is limited to a narrow field of subject matter. This format permits flexibility in revision and publication as the need arises. The reports listed below are for sale by the U.S.G.S., Information Services, Box 25286, Federal Center, Denver, Colorado 80225 (authorized agent of the Superintendent of Documents, Government Printing Office). Prepayment is required. Remit- tance should be made in the form of a check or money order payable to the “U.S. Geological Survey.” Prices are not included because they are subject to change. Current prices can be obtained by writing to the above address. When ordering or inquiring about prices for any of these publications, please give the title, book number, chapter number, and mention the “U.S. Geologi- cal Survey Techniques of Water-Resources Investigations.” Book 1. Collection of Water Data by Direct Measurement Section D. Water Quality 1-D1. Water temperature—influential factors, field measurement, and data presentation, by H. H. Stevens, Jr., J.F. Ficke, and G. F. Smoot: USGS–TWRI book 1, chap. D1. 1975. 65 p. 1-D2. Guidelines for collection and field analysis of ground-water samples for selected unstable constituents, by W.W. Wood: USGS–TWRI book 1, chap. D2. 1976. 24 p. Book 2. Collection of Environmental Data Section D. Surface Geophysical Methods 2-D1. Application of surface geophysics to ground-water investigations, by A.A. R. Zohdy, G.P. Eaton, and D.R. Mabey: USGS–TWRI book 2, chap. D1. 1974. 116 p. 2-D2. Application of seismic-refraction techniques to hydrologic studies, by F.P. Haeni: USGS–TWRI book 2, chap. D2. 1988. 86 p. Section E. Subsurface Geophysical Methods 2-E1. Application of borehole geophysics to water-resources investigations, by W.S. Keys and L.M. MacCary: USGS– TWRI book 2, chap. E1. 1971. 126 p. 2-E2. Borehole geophysics applied to ground-water investigations, by W.S. Keys: USGS–TWRI book 2, chap. E2. 1990. 150 p. Section F. Drilling and Sampling Methods 2-F1. Application of drilling, coring, and sampling techniques to test holes and wells, by Eugene Shuter and W.E. Teasdale: USGS–TWRI book 2, chap. F1. 1989. 97 p. Book 3. Applications of Hydraulics Section A. Surface-Water Techniques 3-A1. General field and office procedures for indirect discharge measurements, by M.A. Benson and Tate Dalrymple: USGS–TWRI book 3, chap. A1. 1967. 30 p. 3-A2. Measurement of peak discharge by the slope-area method, by Tate Dalrymple and M.A. Benson: USGS–TWRI book 3, chap. A2. 1967. 12 p. 3-A3. Measurement of peak discharge at culverts by indirect methods, by G.L. Bodhaine: USGS–TWRI book 3, chap. A3. 1968. 60 p. 3-A4. Measurement of peak discharge at width contractions by indirect methods, by H.F. Matthai: USGS-TWRI book 3, chap. A4. 1967. 44 p. 3-A5. Measurement of peak discharge at dams by indirect methods, by Harry Hulsing: USGS–TWRI book 3. chap. A5. 1967. 29 p. 3-A6. General procedure for gaging streams, by R.W. Carter and Jacob Davidian: USGS–TWRI book 3, chap. A6. 1968. 13 p. 43 TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS OF THE U.S. GEOLOGICAL SURVEY 3-A7.Stage measurement at gaging stations, by T.J. Buchanan and W.P. Somers: USGS–TWRI book 3, chap. A7. 1968. 28 p. 3-A8. Discharge measurements at gaging stations, by T.J. Buchanan and W.P. Somers: USGS–TWRI book 3, chap. A8. 1969. 65 p. 3-A9. Measurement of time of travel in streams by dye tracing, by F.A. Kilpatrick and J.F. Wilson, Jr.: USGS–TWRI book 3, chap. A9. 1989. 27 p. 3-Al0. Discharge ratings at gaging stations, by E.J. Kennedy: USGS–TWRI book 3, chap. A10. 1984. 59 p. 3-A11. Measurement of discharge by the moving-boat method, by G.F. Smoot and C.E. Novak: USGS–TWRI book 3, chap. A11. 1969. 22 p. 3-A12. Fluorometric procedures for dye tracing, Revised, by J.F. Wilson, Jr., E.D. Cobb, and F.A. Kilpatrick: USGS–TWRI book 3, chap. A12. 1986. 34 p. 3-A13. Computation of continuous records of streamflow, by E.J. Kennedy: USGS–TWRI book 3, chap. A13. 1983. 53 p. 3-A14. Use of flumes in measuring discharge, by F.A. Kilpatrick and V.R. Schneider: USGS–TWRI book 3, chap. A14. 1983. 46 p. 3-A15. Computation of water-surface profiles in open channels, by Jacob Davidian: USGS–TWRI book 3, chap. A15. 1984. 48 p. 3-A16. Measurement of discharge using tracers, by F.A. Kilpatrick and E.D. Cobb: USGS–TWRI book 3, chap. A16. 1985. 52 p. 3-A17. Acoustic velocity meter systems, by Antonius Laenen: USGS–TWRI book 3, chap. A17. 1985. 38 p. 3-A18. Determination of stream reaeration coefficients by use of tracers, by F.A. Kilpatrick, R.E. Rathbun, Nobuhiro Yotsukura, G.W. Parker, and L.L. DeLong: USGS–TWRI book 3, chap. A18. 1989. 52 p. 3-A19. Levels at streamflow gaging stations, by E.J. Kennedy: USGS–TWRI book 3, chap. A19. 1990. 31 p. 3-A20. Simulation of soluble waste transport and buildup in surface waters using tracers, by F.A. Kilpatrick: USGS–TWRI book 3, chap. A20. 1993. 38 p. 3-A21 Stream-gaging cableways, by C. Russell Wagner: USGS–TWRI book 3, chap. A21. 1995. 56 p. Section B. Ground-Water Techniques 3-B1. Aquifer-test design, observation, and data analysis, by R.W. Stallman: USGS–TWRI book 3, chap. B1. 1971. 26 p. 3-B2. Introduction to ground-water hydraulics, a programed text for self-instruction, by G.D. Bennett: USGS–TWRI book 3, chap. B2. 1976. 172 p. 3-B3. Type curves for selected problems of flow to wells in confined aquifers, by J.E. Reed: USGS–TWRI book 3, chap. B3. 1980. 106 p. 3-B4. Regression modeling of ground-water flow, by R.L. Cooley and R.L. Naff: USGS–TWRI book 3, chap. B4. 1990. 232 p. 3-B4. Supplement 1. Regression modeling of ground-water flow --Modifications to the computer code for nonlinear regression solution of steady-state ground-water flow problems, by R.L. Cooley: USGS–TWRI book 3, chap. B4. 1993. 8 p. 3-B5. Definition of boundary and initial conditions in the analysis of saturated ground-water flow systems—An introduction, by O.L. Franke, T.E. Reilly, and G.D. Bennett: USGS–TWRI book 3, chap. B5. 1987. 15 p. 3-B6. The principle of superposition and its application in ground-water hydraulics, by T.E. Reilly, O.L. Franke, and G.D. Bennett: USGS–TWRI book 3, chap. B6. 1987. 28 p. 3-B7. Analytical solutions for one-, two-, and three-dimensional solute transport in ground-water systems with uniform flow, by E.J. Wexler: USGS–TWRI book 3, chap. B7. 1992. 190 p. 3-B8. System and boundary conceptualization in ground-water flow simulation, by T.E. Reilly: USGS–TWRI book 3, chap. B8. 2001. 29 p. 44 TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS OF THE U.S. GEOLOGICAL SURVEY Section C. Sedimentation and Erosion Techniques 3-C1. Fluvial sediment concepts, by H.P. Guy: USGS–TWRI book 3, chap. C1. 1970. 55 p. 3-C2. Field methods for measurement of fluvial sediment, by T.K. Edwards and G.D. Glysson: USGS–TWRI book 3, chap. C2. 1999. 89 p. 3-C3. Computation of fluvial-sediment discharge, by George Porterfield: USGS–TWRI book 3, chap. C3. 1972. 66 p. Book 4. Hydrologic Analysis and Interpretation Section A. Statistical Analysis 4-A1. Some statistical tools in hydrology, by H.C. Riggs: USGS–TWRI book 4, chap. A1. 1968. 39 p. 4-A2. Frequency curves, by H.C. Riggs: USGS–TWRI book 4, chap. A2. 1968. 15 p. Section B. Surface Water 4-B1. Low-flow investigations, by H.C. Riggs: USGS–TWRI book 4, chap. B1. 1972. 18 p. 4-B2. Storage analyses for water supply, by H.C. Riggs and C.H. Hardison: USGS–TWRI book 4, chap. B2. 1973. 20 p. 4-B3. Regional analyses of streamflow characteristics, by H.C. Riggs: USGS–TWRI book 4, chap. B3. 1973. 15 p. Section D. Interrelated Phases of the Hydrologic Cycle 4-D1. Computation of rate and volume of stream depletion by wells, by C.T. Jenkins: USGS–TWRI book 4, chap. D1. 1970. 17 p. Book 5. Laboratory Analysis Section A. Water Analysis 5-A1. Methods for determination of inorganic substances in water and fluvial sediments, by M.J. Fishman and L.C. Friedman, editors: USGS–TWRI book 5, chap. A1. 1989. 545 p. 5-A2. Determination of minor elements in water by emission spectroscopy, by P.R. Barnett and E.C. Mallory, Jr.: USGS– TWRI book 5, chap. A2. 1971. 31 p. 5-A3. Methods for the determination of organic substances in water and fluvial sediments, edited by R.L. Wershaw, M.J. Fishman, R.R. Grabbe, and L.E. Lowe: USGS–TWRI book 5, chap. A3. 1987. 80 p. 5-A4. Methods for collection and analysis of aquatic biological and microbiological samples, by L.J. Britton and P.E. Greeson, editors: USGS–TWRI book 5, chap. A4. 1989. 363 p. 5-A5. Methods for determination of radioactive substances in water and fluvial sediments, by L.L. Thatcher, V.J. Janzer, and K.W. Edwards: USGS–TWRI book 5, chap. A5. 1977. 95 p. 5-A6. Quality assurance practices for the chemical and biological analyses of water and fluvial sediments, by L.C. Friedman and D.E. Erdmann: USGS–TWRI book 5, chap. A6. 1982. 181 p. Section C. Sediment Analysis 5-C1. Laboratory theory and methods for sediment analysis, by H.P. Guy: USGS–TWRI book 5, chap. C1. 1969. 58 p. Book 6. Modeling Techniques Section A. Ground Water 6-A1. A modular three-dimensional finite-difference ground-water flow model, by M.G. McDonald and A.W. Harbaugh: USGS–TWRI book 6, chap. A1. 1988. 586 p. 6-A2. Documentation of a computer program to simulate aquifer-system compaction using the modular finite-difference ground-water flow model, by S.A. Leake and D.E. Prudic: USGS–TWRI book 6, chap. A2. 1991. 68 p. 6-A3. A modular finite-element model (MODFE) for areal and axisymmetric ground-water-flow problems, Part 1: Model Description and User’s Manual, by L.J. Torak: USGS–TWRI book 6, chap. A3. 1993. 136 p. 6-A4. A modular finite-element model (MODFE) for areal and axisymmetric ground-water-flow problems, Part 2: Derivation of finite-element equations and comparisons with analytical solutions, by R.L. Cooley: USGS–TWRI book 6, chap. A4. 1992. 108 p. 45 TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS OF THE U.S. GEOLOGICAL SURVEY 6-A5. A modular finite-element model (MODFE) for areal and axisymmetric ground-water-flow problems, Part 3: Design philosophy and programming details, by L.J. Torak: USGS–TWRI book 6, chap. A5, 1993. 243 p. 6-A6. A coupled surface-water and ground-water flow model (MODBRANCH) for simulation of stream-aquifer interaction, by Eric D. Swain and Eliezer J. Wexler: USGS–TWRI book 6, chap. A5,1996. 125 p. Book 7. Automated Data Processing and Computations Section C. Computer Programs 7-C1. Finite difference model for aquifer simulation in two dimensions with results of numerical experiments, by P.C. Trescott, G.F. Pinder, and S.P. Larson: USGS–TWRI book 7, chap. C1. 1976. 116 p. 7-C2. Computer model of two-dimensional solute transport and dispersion in ground water, by L.F. Konikow and J.D. Bredehoeft: USGS–TWRI book 7, chap. C2. 1978. 90 p. 7-C3. A model for simulation of flow in singular and interconnected channels, by R.W. Schaffranek, R.A. Baltzer, and D.E. Goldberg: USGS–TWRI book 7, chap. C3. 1981. 110 p. Book 8. Instrumentation Section A. Instruments for Measurement of Water Level 8-A1. Methods of measuring water levels in deep wells, by M.S. Garber and F.C. Koopman: USGS–TWRI book 8, chap. A1. 1968. 23 p. 8-A2. Installation and service manual for U.S. Geological Survey manometers, by J.D. Craig: USGS–TWRI book 8, chap. A2. 1983. 57 p. Section B. Instruments for Measurement of Discharge 8-B2. Calibration and maintenance of vertical-axis type current meters, by G.F. Smoot and C.E. Novak: USGS–TWRI book 8, chap. B2. 1968. 15 p. Book 9. Handbooks for Water-Resources Investigations Section A. National Field Manual for the Collection of Water-Quality Data 9-A1. National Field Manual for the Collection of Water-Quality Data: Preparations for Water Sampling, by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A1. 1998. 47 p. 9-A2. National Field Manual for the Collection of Water-Quality Data: Selection of Equipment for Water Sampling, edited by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A2. 1998. 94 p. 9-A3. National Field Manual for the Collection of Water-Quality Data: Cleaning of Equipment for Water Sampling, edited by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A3. 1998. 75 p. 9-A4. National Field Manual for the Collection of Water-Quality Data: Collection of Water Samples, edited by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A4. 1999. 156 p. 9-A5. National Field Manual for the Collection of Water-Quality Data: Processing of Water Samples, edited by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A5. 1999, 149 p. 9-A6. National Field Manual for the Collection of Water-Quality Data: Field Measurements, edited by F.D. Wilde and D.B. Radtke: USGS–TWRI book 9, chap. A6. 1998. Variously paginated. 9-A7. National Field Manual for the Collection of Water-Quality Data: Biological Indicators, edited by D.N. Myers and F.D. Wilde: USGS–TWRI book 9, chap. A7. 1997 and 1999. Variously paginated. 9-A8. National Field Manual for the Collection of Water-Quality Data: Bottom-material samples, by D.B. Radtke: USGS– TWRI book 9, chap. A8. 1998. 48 p. 9-A9. National Field Manual for the Collection of Water-Quality Data: Safety in Field Activities, by S.L. Lane and R.G. Fay: USGS–TWRI book 9, chap. A9. 1998. 60 p. 46 THIS PAGE IS INTENTIONALLY BLANK Surface and Quality-of-Water Records for Puerto Rico 47 48 THIS PAGE IS INTENTIONALLY BLANK 66°52 30
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Canal Principal de los Cedros de Diversión Quebrada Río Río Guajataca Guajataca Lago de Guajataca 0108 QUALITY-OF-WATER STATION AND NUMBER 0105 0105 165 EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SURFACE-WATER STATION AND NUMBER CHANNEL FLOW DIRECTION Figure 11. Río Guajataca basin. 49 AGUADILLA ISABELA QUEBRADILLAS CAMUY ATLANTIC OCEAN Basin area PUERTO RICO SAN SEBASTIÁN MOCA LARES 0114 202 165 1001 0110 0108 010790 010720 0105 0 0 1 1 2 2 3 3 4 4 5 MILES 5 KILOMETERS 50 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR LOCATION.--Lat 18°18'01", long 66°52'24", Hydrologic Unit 21010001 at bridge on Highway 111, 0.1 mi (0.2 km) upstream from Quebrada Anón, and 0.4 mi (0.6 km) east of Lares. DRAINAGE AREA.--3.16 mi2 (8.18 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1959 to February 1962 (annual low-flow measurements only), January 1963 to April 1969 (monthly measurements only), May 1969 to December 1970, (February to May 1971 and March 1974 to November 1989, monthly measurements only), December 1989 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 935 ft (285 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. Small diversion above station for sewage treatment plant; effluent re-enters stream below station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 12 e29 12 2.8 2.9 3.7 2.4 3.7 4.1 1.1 4.3 3.7 2 9.2 e44 49 2.8 2.9 2.8 1.7 4.7 3.7 4.6 3.0 3.1 3 8.4 e31 13 3.2 3.4 2.9 2.7 23 3.3 2.4 2.4 2.5 4 8.5 e61 10 4.4 3.5 2.9 2.1 17 3.2 1.8 3.9 47 5 8.6 e31 13 3.4 4.5 2.8 1.4 4.5 3.0 .94 2.6 23 6 10 e19 10 2.7 3.0 2.7 2.4 2.4 3.0 2.1 2.3 9.7 7 47 e19 10 2.2 3.0 2.5 2.7 2.1 3.0 2.9 2.5 5.9 8 16 e15 9.5 2.9 3.0 2.0 2.3 29 2.7 1.6 2.1 7.0 9 10 e14 8.9 2.1 2.9 2.8 1.5 68 11 28 1.9 5.9 10 8.2 e13 9.3 1.9 2.5 2.5 1.4 45 3.7 6.9 2.9 5.6 11 12 e12 8.0 1.7 2.5 2.4 1.4 183 3.1 19 1.8 5.5 12 11 e11 7.9 1.6 2.8 2.3 1.8 44 3.4 10 1.7 4.7 13 24 e11 7.6 1.7 2.8 2.2 2.2 19 12 15 1.6 4.3 14 12 e12 7.3 1.7 2.8 3.3 1.5 13 7.2 8.0 1.5 3.4 15 112 e37 7.3 10 3.1 2.1 1.6 9.4 4.1 4.6 1.9 3.3 16 95 23 6.2 5.7 3.8 2.2 1.7 8.4 15 3.8 7.2 29 17 53 58 6.3 4.0 3.6 2.1 1.6 51 4.9 3.6 2.9 7.0 18 43 71 6.0 2.3 3.6 1.9 1.5 14 3.5 4.4 2.0 6.1 19 27 78 5.7 2.0 3.8 1.8 1.7 7.9 3.3 3.6 1.8 6.4 20 17 35 5.3 2.6 4.2 1.8 5.4 7.1 12 18 2.3 9.5 21 21 25 5.0 4.2 3.5 2.0 1.8 5.6 15 4.9 3.2 6.0 22 e23 22 4.8 3.1 19 1.9 23 5.0 5.5 3.5 3.8 27 23 e27 17 4.2 3.1 39 2.8 6.3 4.6 4.6 3.2 43 9.2 24 e15 15 4.4 3.4 6.5 2.5 3.7 19 4.3 3.1 3.7 6.8 25 e53 13 4.5 4.0 3.1 1.6 2.7 7.0 4.4 3.1 7.4 5.9 26 e21 13 3.8 2.9 4.0 2.0 4.4 5.7 29 2.7 4.9 14 27 e16 12 3.7 2.8 4.5 2.4 2.1 4.6 5.6 3.7 35 8.3 28 e43 11 3.4 2.8 4.3 1.7 1.8 17 3.1 3.0 9.5 5.8 29 e26 11 5.1 3.1 5.1 2.0 1.8 6.6 2.8 3.1 4.3 5.1 30 e33 11 3.4 2.8 --- 3.5 1.6 4.5 2.4 4.5 5.6 4.4 31 e67 --- 3.4 3.0 --- 3.6 --- 4.0 --- 3.3 3.6 --- TOTAL 888.9 774 258.0 96.9 153.6 75.7 90.2 639.8 185.9 180.44 176.6 285.1 MEAN 28.7 25.8 8.32 3.13 5.30 2.44 3.01 20.6 6.20 5.82 5.70 9.50 MAX 112 78 49 10 39 3.7 23 183 29 28 43 47 MIN 8.2 11 3.4 1.6 2.5 1.6 1.4 2.1 2.4 .94 1.5 2.5 AC-FT 1760 1540 512 192 305 150 179 1270 369 358 350 565 CFSM 9.07 8.16 2.63 .99 1.68 .77 .95 6.53 1.96 1.84 1.80 3.01 IN. 10.46 9.11 3.04 1.14 1.81 .89 1.06 7.53 2.19 2.12 2.08 3.36 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2000, BY WATER YEAR (WY) MEAN 17.8 9.93 4.18 3.37 2.98 2.81 3.55 11.2 8.42 4.67 6.57 14.7 MAX 33.7 25.8 8.32 8.91 7.21 10.6 8.16 25.4 23.4 9.85 11.1 45.2 (WY) 1991 2000 2000 1997 1996 1999 1999 1999 1999 1969 1996 1998 MIN 8.52 2.42 1.35 .66 .93 .92 1.09 2.37 1.70 1.73 3.34 5.95 (WY) 1995 1998 1991 1991 1992 1994 1994 1997 1997 1997 1970 1993 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1969 - 2000 ANNUAL TOTAL 5337.7 3805.14 ANNUAL MEAN 14.6 10.4 7.48 HIGHEST ANNUAL MEAN 12.6 1999 LOWEST ANNUAL MEAN 4.13 1994 HIGHEST DAILY MEAN 121 May 28 183 May 11 505 Sep 22 1998 LOWEST DAILY MEAN 1.8 Feb 24 .94 Jul 5 .47 Jan 13 1991 ANNUAL SEVEN-DAY MINIMUM 2.2 Feb 19 1.6 Apr 9 .51 Jan 9 1991 INSTANTANEOUS PEAK FLOW 2550 Oct 15 5300 Oct 7 1990 INSTANTANEOUS PEAK STAGE 16.65 Oct 15 21.30 Oct 7 1990 ANNUAL RUNOFF (AC-FT) 10590 7550 5420 ANNUAL RUNOFF (CFSM) 4.63 3.29 2.37 ANNUAL RUNOFF (INCHES) 62.84 44.79 32.15 10 PERCENT EXCEEDS 35 26 17 50 PERCENT EXCEEDS 8.9 4.3 3.7 90 PERCENT EXCEEDS 2.5 1.9 1.0 e Estimated 51 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR--Continued O N D 1999 J F M A M J J A S 2000 0.1 0.2 0.5 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 52 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR--Continued WATER-QUALITY RECORDS LOCATION.--Lat 18°18'01", long 66°52'24", at bridge on Highway 111 (km 32.9), 0.1 mi (0.2 km) upstream from Quebrada Anón, and 0.4 mi (0.6 km) northeast of Lares plaza. DRAINAGE AREA.--3.16 mi2 (8.18 km2). PERIOD OF RECORD.--Water years 1958-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) OCT 28... 1730 67 111 7.4 23.1 500 7.5 91 28 >600000 86000 FEB 16... 1630 4.4 210 7.9 22.5 27 7.0 81 <10 K860 360 APR 24... 1550 3.3 224 7.5 24.5 25 7.2 90 <10 5700 2900 AUG 21... 1430 2.9 238 8.0 28.1 6.5 7.9 105 <10 3200 990 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) OCT 28... 39 11.3 2.56 4.6 .3 2.7 38 <1.0 4.8 5.7 FEB 16... -- -- -- -- -- -- 75 -- -- -- APR 24... 83 23.8 5.63 10.3 .5 2.6 77 <1.0 13.8 13.2 AUG 21... 84 24.0 5.75 11.4 .5 2.1 82 -- 6.7 11.3 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 28... <.1 21.8 76 13.8 705 1.14 .06 1.2 .11 2.2 FEB 16... -- -- -- -- 37 -- <.01 1.3 .03 .26 APR 24... <.1 25.6 141 1.27 28 1.19 .01 1.2 .02 -- AUG 21... <.1 30.0 140 1.10 <10 1.19 .01 1.2 .02 -- NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 28... 2.3 3.5 15.5 .480 <3 108 E18 .2 5 E15 FEB 16... .29 1.6 7.0 .110 -- -- -- -- -- -- APR 24... <.20 -- -- .050 <3 26.5 E14 <.1 <1 <20 AUG 21... <.20 -- -- .050 -- -- -- -- -- -- 53 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 28... 12300 9 841 <.3 <3 <1 50 <.01 <4 <.16 FEB 16... -- -- -- -- -- -- -- -- -- -- APR 24... 480 <1 46 <.3 <3 <1 E21 <.01 7 <.02 AUG 21... -- -- -- -- -- -- -- -- -- -- 54 RIO GUAJATACA BASIN 50010800 LAGO GUAJATACA AT DAMSITE NEAR QUEBRADILLAS, PR LOCATION.--Lat 18°24'02", long 66°55'25", Hydrologic Unit 21010002, on right bank, in a concrete intake tower at Damsite, 5.2 mi (8.4 km) southeast from Quebradillas plaza, 0.5 mi (0.8 km) northeast from Iglesia San Antonio de Padua and 2.8 mi (4.5 km) from Escuela Segunda Unidad Baldorioty de Castro. DRAINAGE AREA.--24.6 mi2 (63.71 km2) ELEVATION RECORDS PERIOD OF RECORD.--April 1995 to current year. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Guajataca was completed in 1928. The dam is a semihydraulic earthfill structure about 123 ft (37 m) high, a top width of 31 ft (9.5 m) at crest elevation of 664 ft (202.5 m), a base width of 623 ft (190 m), a crest length of 1,036 ft (316 m) and has a maximum storage capacity of 49,200 acre- feet (60.6 hm3). The Guajataca Dam is owned by the Puerto Rico Electric Power Authority (P.R.E.P.A) and provides water for the municipalities of Aguadilla, Isabela, Moca, Aguada and Quebradillas although its primary purpose is for agricultural irrigation for the flatlands of the area. Gage-height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 00-4044,January 1999. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 648.3 ft (197.60 m), Sept. 23, 1998; minimum elevation, 608.07 ft (185.34 m) May 17, 1998. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 643.28 ft (196.07 m), Nov. 5; minimum elevation, 628.51 ft (191.57 m), May 2. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 00-4044,Puerto Rico-1999) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 557 0 616 13,393 577 916 636 26,332 597 5,253 646 34,277 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 641.48 642.98 A 641.14 638.54 635.45 631.64 628.61 637.37 633.63 630.97 630.90 2 641.69 642.91 A 641.06 638.43 635.32 631.57 629.99 637.22 633.54 630.84 630.99 3 641.71 643.03 A 641.07 638.33 635.21 631.50 630.92 637.09 633.40 630.71 631.20 4 641.69 643.25 A 641.08 638.22 635.08 631.42 631.16 636.94 633.36 630.57 631.92 5 641.66 643.22 A 641.02 638.13 634.97 631.33 631.02 636.77 633.25 630.42 632.55 6 641.95 643.00 A 640.95 638.02 634.84 631.23 630.73 636.62 633.11 630.27 632.83 7 642.22 643.11 A 640.87 637.92 634.73 631.13 630.44 636.44 633.34 630.31 632.85 8 642.20 643.02 A 640.78 637.82 634.61 631.03 630.86 636.28 633.49 630.17 632.81 9 642.09 642.84 642.62 640.71 637.71 634.48 630.92 632.36 636.19 633.52 630.01 632.83 10 642.02 642.83 642.59 640.62 637.61 634.36 630.87 632.27 636.06 633.44 630.07 632.88 11 642.02 642.85 642.56 640.54 637.50 634.23 630.76 637.09 635.91 633.35 629.97 632.87 12 642.00 642.78 642.50 640.45 637.39 634.11 630.65 638.13 635.76 633.26 629.83 632.78 13 642.35 642.71 642.47 640.37 637.28 633.99 630.54 637.64 635.63 633.19 629.68 632.70 14 642.40 642.75 642.42 640.29 637.17 633.93 630.43 636.70 635.52 633.12 629.55 632.65 15 642.50 642.70 642.35 640.28 637.06 633.80 630.32 636.62 635.39 633.01 629.61 632.55 16 642.43 642.52 642.29 640.23 636.94 633.68 630.21 636.90 635.42 632.87 629.56 632.60 17 642.15 642.54 642.22 640.15 636.83 633.54 630.11 638.22 635.31 632.73 629.46 632.61 18 642.08 642.71 642.17 640.06 636.70 633.43 629.99 638.54 635.16 632.61 629.32 632.55 19 642.04 643.12 642.09 639.97 636.58 633.30 629.89 638.53 635.02 632.56 629.17 632.50 20 641.97 643.15 642.03 639.85 636.46 633.18 629.84 638.47 634.85 632.48 629.02 632.50 21 642.00 642.99 641.97 639.75 636.35 633.04 629.74 638.38 634.76 632.40 628.88 632.70 22 642.09 642.92 641.90 639.64 636.29 632.92 629.95 638.29 634.69 632.25 628.78 632.96 23 642.04 A 641.84 639.53 636.24 632.79 630.41 638.23 634.54 632.12 629.15 633.06 24 641.93 A 641.76 639.42 636.15 632.64 630.57 638.18 634.36 631.98 629.11 633.11 25 642.26 A 641.69 639.31 636.03 632.48 630.60 638.09 634.21 631.87 629.10 633.55 26 642.27 A 641.61 639.20 635.92 632.33 630.35 637.97 634.34 631.74 629.54 634.62 27 642.15 A 641.52 639.08 635.80 632.18 629.99 637.84 634.26 631.62 630.37 635.46 28 642.31 A 641.45 638.97 635.69 631.93 629.59 637.82 634.11 631.49 631.03 635.58 29 642.20 A 641.39 638.87 635.56 631.71 629.22 637.77 633.94 631.36 631.09 636.42 30 642.25 A 641.31 638.76 --- 631.66 628.86 637.66 633.79 631.23 631.03 636.70 31 643.04 --- 641.23 638.65 --- 631.66 --- 637.53 --- 631.11 630.98 --- MAX 643.04 643.25 642.62 641.14 638.54 635.45 631.64 638.54 637.37 633.63 631.09 636.70 MIN 641.48 642.52 641.23 638.65 635.56 631.66 628.86 628.61 633.79 631.11 628.78 630.90 A No gage-height record 55 RIO GUAJATACA BASIN 50010800 LAGO GUAJATACA AT DAMSITE NEAR QUEBRADILLAS, PR--Continued O N D 1999 J F M A M J J A S 2000 628 630 632 634 636 638 640 642 644 ELEVATION, IN FEET Gap indicates missing record 56 RIO GUAJATACA BASIN 50011000 CANAL PRINCIPAL DE DIVERSIONES AT LAGO DE GUAJATACA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'02", long 66°55'27", off Highway 476 at Lago Guajataca outlet, 3.0 mi (4.8 km) southwest of Segunda Unidad Baldorioty de Castro, and 5.3 mi (8.5 km) south of Quebradillas Plaza. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1958-64, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) OCT 29... 1245 40 306 7.7 25.7 1.8 .7 8 12 K53 K29 FEB 22... 1345 -- 316 7.8 24.2 .8 2.3 28 <10 44 56 MAY 11... 0630 65 317 7.3 25.5 6.3 2.4 30 <10 37 41 AUG 21... 1530 70 296 7.3 27.6 6.3 1.8 24 <10 35 K12 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) OCT 29... 140 49.9 3.30 4.9 .2 2.4 136 <1.0 6.6 6.9 FEB 22... -- -- -- -- -- -- 162 -- -- -- MAY 11... 130 46.2 3.67 5.4 .2 2.1 136 <1.0 7.5 8.2 AUG 21... -- -- -- -- -- -- 125 -- -- -- SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 29... <.1 21.5 177 19.1 6 .05 .01 .1 .14 .08 FEB 22... -- -- -- -- <1 -- <.01 .1 .08 .16 MAY 11... .2 5.0 160 28.1 <10 -- <.01 .02 .43 .10 AUG 21... -- -- -- -- <10 -- <.01 <.1 .29 .27 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 29... .22 .28 1.2 .020 E2 17.6 E10 <.1 <1 <20 FEB 22... .24 .30 1.3 <.020 -- -- -- -- -- -- MAY 11... .53 .55 2.4 <.020 E1 10.2 23 <.1 <1 <20 AUG 21... .56 -- -- <.020 -- -- -- -- -- -- 57 RIO GUAJATACA BASIN 50011000 CANAL PRINCIPAL DE DIVERSIONES AT LAGO DE GUAJATACA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 29... 140 E1 128 <.3 <3 <1 <31 <.01 6 .03 FEB 22... -- -- -- -- -- -- -- -- -- -- MAY 11... 130 <1 173 <.3 <3 <1 <31 <.01 <4 <.02 AUG 21... -- -- -- -- -- -- -- -- -- -- 58 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR. WATER-QUALITY RECORDS LOCATION.--Lat 18°28'31", long 66°57'46", Hydrologic Unit 21010002, on left bank at ford 1.7 mi (2.7 km) upstream from bridge on highway 2, 1.6 mi (2.6 km) west of Quebradillas plaza, 2.1 mi (3.4 km) upstream from Atlantic Ocean, and 6.6 mi (10.6 km) downstream from Lago Guajataca. DRAINAGE AREA.--Indeterminate PERIOD OF RECORD.--Water years 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) OCT 29... 1055 -- 312 8.2 25.2 8.9 7.4 90 <10 K780 570 FEB 24... 0850 16 549 8.0 23.3 1.3 5.3 62 <10 K22 210 APR 26... 1015 19 454 7.9 24.3 2.3 6.8 81 <10 560 460 SEP 07... 1215 15 468 7.8 25.9 .3 8.1 100 <10 120 160 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) OCT 29... 150 54.0 3.22 5.0 .2 1.9 146 <1.0 6.2 7.7 FEB 24... -- -- -- -- -- -- 217 -- -- -- APR 26... 190 67.4 6.00 13.5 .4 1.8 185 <1.0 13.1 25.5 SEP 07... 210 73.4 6.51 14.4 .4 1.3 190 -- 9.1 24.5 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 29... <.1 6.9 172 -- 10 .35 .02 .4 .02 .23 FEB 24... -- -- -- -- 1 2.69 .01 2.7 .02 -- APR 26... <.1 6.1 245 12.6 2 -- <.01 1.9 .01 -- SEP 07... <.1 6.2 250 10.3 <10 -- <.01 1.5 .01 -- NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 29... .25 .62 2.7 .040 <3 14.7 E13 <.1 E1 <20 FEB 24... <.20 -- -- <.020 -- -- -- -- -- -- APR 26... <.20 -- -- <.020 <3 12.0 23 <.1 1 <20 SEP 07... <.20 -- -- .090 -- -- -- -- -- -- 59 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR.--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 29... 260 <1 44 <.3 <3 <1 <31 <.01 <4 .03 FEB 24... -- -- -- -- -- -- -- -- -- -- APR 26... 100 <1 33 <.3 <3 <1 <31 <.01 5 <.02 SEP 07... -- -- -- -- -- -- -- -- -- -- THIS PAGE IS INTENTIONALLY BLANK 60 66°42 30
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Río Río Río Piedras Río Caño Tiburones Camuy River Underground A n g e l e s C r i m i n a l e s CAÑO TIBURONES FLOW DIRECTION 0148 1027 EXPLANATION WELL AND WELL NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SURFACE-WATER STATION AND NUMBER Figure 12. Río Camuy basin. 61 QUEBRADILLAS CAMUY HATILLO ARECIBO ATLANTIC OCEAN LARES UTUADO 0148 Basin area PUERTO RICO 0 0 1 1 2 2 3 3 4 4 5 MILES 5 KILOMETERS 1027 1026 62 RIO CAMUY BASIN 50014800 RIO CAMUY NEAR BAYANEY, PR LOCATION.--Lat 18°23'48", long 66°49'04", Hydrologic Unit 21010002, on left bank at Highway 488, 1.4 mi (2.2 km) southeast of school at Santiago, 0.9 mi (1.4 km) northwest from Escuela Manuel A. Rivera at Bayaney and 9.1 mi (14.6 km) upstream from mouth. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--May 1984 to current year. GAGE.--Water-stage recorder. Elevation of gage is 341 ft (104 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 128 316 173 83 61 52 39 e66 e55 47 48 85 2 107 281 1160 82 60 51 38 e93 e53 45 51 99 3 61 428 536 171 67 50 38 e112 e50 47 47 127 4 52 347 252 199 62 49 38 e201 e49 42 48 173 5 49 309 286 127 59 49 38 e85 e47 54 48 329 6 51 245 260 106 60 49 36 e62 e47 43 45 221 7 143 353 205 101 58 48 36 e55 e49 133 46 132 8 84 317 185 97 58 48 e44 e245 e49 134 44 100 9 58 207 159 99 58 47 e37 e619 e100 132 43 161 10 50 248 149 89 57 46 e36 e464 e46 120 46 147 11 72 198 138 85 56 45 e36 e663 e42 74 55 107 12 70 168 130 84 55 45 e35 e269 e47 76 42 90 13 224 153 123 81 54 45 e35 e173 e114 e68 41 83 14 172 186 118 83 55 44 e34 e124 e77 79 40 78 15 235 233 113 114 55 44 e34 e106 e51 62 42 75 16 368 221 110 148 52 43 e33 e97 e115 58 48 172 17 359 355 109 92 51 44 e34 e223 e62 52 66 114 18 226 478 105 81 51 43 e34 e116 e45 50 e46 107 19 144 720 102 76 51 43 e34 e90 e42 62 40 114 20 115 451 100 e73 50 42 e61 e83 e95 72 39 134 21 152 318 100 69 50 42 e47 e76 e138 78 36 117 22 234 280 104 69 104 43 e111 e71 e69 60 e37 230 23 147 247 99 69 190 41 e84 e65 e58 52 468 e189 24 119 214 95 68 147 45 e66 e122 50 51 146 135 25 856 195 98 67 82 43 e58 e83 48 79 134 e115 26 416 179 90 66 68 40 e67 e72 90 72 257 127 27 337 165 88 65 62 45 e50 e64 73 58 203 225 28 273 155 86 63 56 40 e47 e97 59 55 249 137 29 215 148 105 64 54 e40 e46 e82 50 52 161 131 30 197 170 91 65 --- 39 e45 e61 47 50 111 130 31 420 --- 86 62 --- 42 --- e57 --- 54 92 --- TOTAL 6134 8285 5555 2798 1943 1387 1371 4796 1917 2111 2819 4184 MEAN 198 276 179 90.3 67.0 44.7 45.7 155 63.9 68.1 90.9 139 MAX 856 720 1160 199 190 52 111 663 138 134 468 329 MIN 49 148 86 62 50 39 33 55 42 42 36 75 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1984 - 2000, BY WATER YEAR (WY) MEAN 203 132 75.9 60.2 51.6 49.6 83.5 167 120 75.8 98.1 193 MAX 427 276 179 163 96.4 93.7 202 624 322 109 187 726 (WY) 1986 2000 2000 1997 1996 1999 1986 1986 1999 1989 1998 1998 MIN 81.6 53.4 36.5 33.1 29.1 23.7 28.0 43.2 42.7 38.8 47.9 61.8 (WY) 1988 1998 1998 1991 1998 1994 1994 1989 1997 1994 1993 1997 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1984 - 2000 ANNUAL TOTAL 54804 43300 ANNUAL MEAN 150 118 109 HIGHEST ANNUAL MEAN 179 1986 LOWEST ANNUAL MEAN 61.5 1994 HIGHEST DAILY MEAN 1160 Dec 2 1160 Dec 2 9010 Sep 22 1998 LOWEST DAILY MEAN 41 Mar 17 33 Apr 16 16 Mar 18 1994 ANNUAL SEVEN-DAY MINIMUM 43 Feb 18 34 Apr 13 17 Mar 16 1994 INSTANTANEOUS PEAK FLOW 3970 Dec 2 11600 Sep 22 1998 INSTANTANEOUS PEAK STAGE 15.07 Dec 2 21.69 Sep 22 1998 INSTANTANEOUS LOW FLOW 33 Apr 15 15 Mar 22 1994 10 PERCENT EXCEEDS 337 245 215 50 PERCENT EXCEEDS 99 76 68 90 PERCENT EXCEEDS 51 42 34 e Estimated 63 RIO CAMUY BASIN 50014800 RIO CAMUY NEAR BAYANEY, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND THIS PAGE IS INTENTIONALLY BLANK 64 66°47 30
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66°32 30
 Río Río Río Río Río Río Río Río Jauca Río Río Río Cidra Río Río Río Río Río Caricaboa Saliente G r a n d e Grande G r a n d e de de de J a y u y a Arecibo Arecibo Río Río Lago Caonillas Lago Pellejas Lago Adjuntas Lago Viví Lago Garzas Lago Jordan Lago Dos Bocas Caño Tiburones Tanamá Limón Limón La Venta Yunes C a o n i l l a s C a o n il las Viví Tunnel Tunnel Tunnel Tunnel Tunnel Viví Vacas Pellejas 0280 CAÑO TIBURONES FLOW DIRECTION TUNNEL FLOW DIRECTION QUALITY-OF-WATER STATION AND NUMBER 0280 0205 205 0201 EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SEDIMENT STATION AND NUMBER SURFACE-WATER STATION AND NUMBER Figure 13. Río Grande de Arecibo basin. 65 HATILLO ARECIBO BARCELONETA Basin area PUERTO RICO ATLANTIC OCEAN ADJUNTAS JAYUYA UTUADO FLORIDA 0 0 1 1 2 2 3 3 4 4 5 MILES 5 KILOMETERS 0284 027750 0290 027250 027090 0271 025110 026140 0250 026050 026025 0280 0205 204 1051 1055 1056 1052 1053 1054 1057 205 020050 0201 0270 0264 024950 0217 021030 025850 025155 66 RIO GRANDE DE ARECIBO BASIN 50020100 LAGO GARZAS NEAR ADJUNTAS, PR LOCATION.--Lat 18°08'20", long 66°44'29",Hydrologic Unit 21010002, in power gate tower of Garzas Dam on Río Vacas, 1.7 mi (2.7 km) upstream from Río Garzas, and 2.2 mi (3.5 km) southwest of Adjuntas. DRAINAGE AREA.--15.6 mi2 (40.4 km2). ELEVATION RECORDS PERIOD OF RECORD.--January 1988 to May 1989, March 1993 to current year. GAGE.--Water-stage recorder. Datum of gage is 2,400.00 ft (731.520 m) above mean sea level. Prior to May 25, 1988 at datum 2,376.80 ft (724.449 m), May 25 to July 13, 1988 at datum 2,338.08 ft (712.647 m), July 14, 1988 to May 25, 1989 at datum 2,337.82 ft (712.560 m), above mean sea level. REMARKS.--Lake is formed by earthfill dam completed in 1943. Outflow from lake controlled by vertical-lift sluice gate and fixed-crest concrete spillway. Spillway elevation, 2,415.00 ft (736.09 m). Lake is used for irrigation and power production. Operated by P.R. Electric Power Authority. Gage-height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 99-4143,September 1996. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,418.28 ft (737.092 m),Sept. 22, 1998;minimum elevation,2,364.79 A ft (720.788 m), Aug. 23, 1988. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation,2,416.80 ft (736.64 m), Aug.23;minimum elevation,2,395.87 ft (730.26 m), May 4. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 99-4143,1996) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 2,317 0 2,376 1,419 2,336 243 2,399 2,700 2,359 794 2,415 4,143 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2413.53 2412.83 2413.24 2414.79 2414.62 2411.28 2403.59 A 2412.67 2414.44 2413.66 2414.87 2 2413.42 2414.14 2414.04 2414.39 2414.72 2411.00 2403.38 A 2414.65 2414.64 2414.59 2414.86 3 2414.03 2414.84 2414.37 2414.67 2414.74 2410.72 2403.32 A 2414.69 2414.63 2414.65 2414.86 4 2414.49 2414.88 2414.41 2414.77 2414.75 2410.37 2403.14 2398.13 2414.69 2414.72 2414.56 2414.84 5 2414.85 2414.95 2414.46 2414.88 2414.75 2409.95 2402.94 2398.30 2414.69 2414.65 2414.61 2414.84 6 2414.57 2414.92 2414.48 2414.81 2414.75 2409.35 2402.80 2398.43 2414.76 2414.56 2414.67 2414.85 7 2414.04 2414.92 2414.53 2414.80 2414.50 2409.14 2402.61 2398.43 2414.76 2414.63 2414.60 2414.81 8 2413.63 2414.92 2414.57 2414.79 2414.66 2408.68 2402.41 2398.43 2414.57 2414.74 2414.63 2414.79 9 2414.17 2414.90 2412.42 2414.79 2414.74 2408.38 2402.23 2398.44 2414.71 2414.74 2414.49 A 10 2414.68 2414.91 2412.92 2414.80 2414.74 2408.03 2402.01 2402.35 2414.74 2414.61 2414.59 A 11 2414.29 2414.91 2413.39 2413.88 2414.71 2407.72 2401.80 2402.54 2414.75 2414.71 2414.55 A 12 2414.98 2414.91 2413.88 2414.50 2414.73 2407.34 2401.58 2402.78 2414.84 2414.59 2414.63 A 13 2414.19 2414.91 2414.31 2414.74 2414.74 2406.98 2401.58 2403.19 2414.85 2414.66 2414.66 2414.96 14 2413.63 2414.90 2414.71 2414.77 2414.61 2406.82 2401.41 2403.27 2414.83 2414.46 2414.18 2415.09 15 2413.02 2412.79 2414.78 2414.80 2414.50 2406.72 2401.19 2403.46 2414.77 2414.62 2414.55 2414.91 16 2413.48 2412.14 2414.78 2414.78 2414.38 2406.51 2400.95 2403.40 2414.86 2414.66 2414.39 2415.09 17 2414.85 2414.15 2414.78 2414.44 2414.12 2406.31 A 2408.64 2414.78 2414.77 2414.47 2415.48 18 2412.16 2415.16 2414.79 2414.65 2413.89 2406.09 2399.32 2409.57 2414.77 2414.44 2414.47 2414.89 19 2410.85 A 2414.79 2414.73 2413.70 2405.86 2399.46 2410.12 2413.87 2414.59 2414.57 2414.88 20 2409.43 2413.69 2414.79 2414.36 2413.46 2405.67 A 2410.62 2414.12 A 2414.62 2415.02 21 A 2413.56 2414.78 2414.56 2413.35 2405.46 2399.61 2410.99 2414.37 2414.45 2414.59 2414.87 22 A 2413.93 2414.80 2414.72 2413.12 2405.26 2399.50 2411.38 2414.57 2414.58 2415.61 2414.99 23 A 2413.99 2412.59 2414.76 2412.95 2404.99 2399.15 2411.90 2414.59 2414.68 2412.82 2414.94 24 A 2414.03 2414.43 2414.50 2412.80 2404.80 A 2412.24 2414.56 2414.37 2414.81 2414.93 25 A 2414.06 2414.72 2414.75 2412.56 2404.57 A 2412.56 2414.46 A 2414.90 2414.93 26 A 2414.10 2414.78 2414.78 2412.33 2404.33 A 2412.65 2414.39 2414.24 2414.87 2414.91 27 2404.88 2414.14 2414.46 2414.76 2412.08 2404.06 A 2412.66 2414.23 2414.18 2414.87 2414.66 28 2407.41 2414.19 2414.76 2414.76 2411.83 2403.97 A 2412.66 2414.12 2413.89 2414.88 2414.76 29 2408.11 2412.08 2414.84 2414.76 2411.55 2403.81 A 2412.66 2414.07 2413.89 2414.88 2412.33 30 2409.04 2411.49 2414.79 2414.75 --- 2403.63 A 2412.66 2414.26 2413.80 2414.91 2411.24 31 2412.02 --- 2414.79 2414.44 --- 2403.63 --- 2412.67 --- 2413.56 2414.84 --- MAX 2414.98 2415.16 2414.84 2414.88 2414.75 2411.28 2403.59 2412.67 2414.86 2414.77 2415.61 2415.48 MIN 2404.88 2411.49 2412.42 2413.88 2411.55 2403.63 2399.15 2398.13 2412.67 2413.56 2412.82 2411.24 A No gage-height record 67 RIO GRANDE DE ARECIBO BASIN 50020100 LAGO GARZAS NEAR ADJUNTAS, PR--Continued O N D 1999 J F M A M J J A S 2000 2395 2400 2405 2410 2415 2420 ELEVATION, IN FEET Gap indicates missing record 68 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR LOCATION.--Lat 18°10'54', long 66°44'12", Hydrologic Unit 21010002, at Highway 135 bridge junction with Hwy.10, 1.4 mi (2.25 km) south from Lago Adjuntas, and 1.5 mi (2.4 km) northwest of Adjuntas plaza. DRAINAGE AREA.--12.7 mi2 (32.9 km2), this does not include 6.0 mi2 (15.6 km2) above Lago Garzas. PERIOD OF RECORD.--November 1946 to April 1950 (operated by Puerto Rico Water Resources Authority), March to September 2000. GAGE.--Water-stage recorder. Elevation of gage is 1,443 ft (440 m), from topographic map. REMARKS.--Records poor. Flow affected by Lago Garzas, 2.63 mi (4.23 km) and sewage treatment plant 1.1 mi (1.77 km) upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14 9.4 19 20 e30 e110 2 13 10 19 25 e26 e76 3 13 30 26 23 e20 e67 4 11 84 27 23 e18 e58 5 10 36 26 e24 e14 e59 6 10 218 26 e22 e15 e59 7 15 111 25 e18 e16 e55 8 10 152 23 e22 e14 e51 9 12 76 18 e25 e14 e48 10 10 43 23 e23 e13 e46 11 10 60 25 e20 e14 e48 12 9.7 40 e38 e21 e12 e45 13 18 31 e149 e18 e14 e42 14 11 27 86 e20 e15 e61 15 9.8 25 50 e16 e24 e44 16 9.8 22 95 e18 e15 e98 17 10 129 53 e23 e13 e169 18 14 44 37 e23 e12 e683 19 20 30 29 e15 e12 e271 20 41 26 63 e15 e13 e291 21 27 26 29 e15 e14 e190 22 14 38 23 e15 e334 e217 23 11 26 23 e16 e1510 e202 24 11 24 22 e18 e92 e157 25 10 24 20 e16 e107 e125 26 10 22 20 e15 e149 e108 27 9.7 22 19 e15 e82 e166 28 9.5 21 19 e15 e65 e156 29 13 9.6 20 18 e16 e63 e80 30 12 9.7 22 29 e16 e119 e80 31 33 --- 19 --- e18 e72 --- TOTAL 58 392.8 1467.4 1079 589 2931 3862 MEAN 19.3 13.1 47.3 36.0 19.0 94.5 129 MAX 33 41 218 149 25 1510 683 MIN 12 9.5 9.4 18 15 12 42 AC-FT 115 779 2910 2140 1170 5810 7660 CFSM 1.03 .70 2.53 1.92 1.02 5.06 6.88 IN. .12 .78 2.92 2.15 1.17 5.83 7.68 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1947 - 2000, BY WATER YEAR (WY) MEAN 73.1 46.3 35.8 22.4 28.6 17.0 16.7 29.5 29.3 31.6 57.7 94.0 MAX 89.5 63.4 40.6 29.6 56.9 21.6 30.6 47.3 36.0 49.3 94.5 129 (WY) 1948 1949 1948 1949 1950 1949 1950 2000 2000 1949 2000 2000 MIN 50.3 27.3 30.8 19.7 16.4 11.2 10.4 12.2 19.4 18.0 26.9 55.8 (WY) 1950 1950 1947 1948 1949 1948 1948 1948 1948 1947 1947 1947 SUMMARY STATISTICS FOR 2000 WATER YEAR WATER YEARS 1947 - 2000 ANNUAL MEAN 41.2 HIGHEST ANNUAL MEAN 41.4 1948 LOWEST ANNUAL MEAN 41.0 1949 HIGHEST DAILY MEAN 1510 Aug 23 1510 Aug 23 2000 LOWEST DAILY MEAN 9.4 May 1 7.6 May 10 1948 ANNUAL SEVEN-DAY MINIMUM 9.7 Apr 25 8.6 May 6 1948 ANNUAL RUNOFF (AC-FT) 29850 ANNUAL RUNOFF (CFSM) 2.20 ANNUAL RUNOFF (INCHES) 29.93 10 PERCENT EXCEEDS 121 75 50 PERCENT EXCEEDS 23 23 90 PERCENT EXCEEDS 11 12 e Estimated 69 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR--Continued O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND Gap indicates missing record 70 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1969-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) NOV 09... 1125 84 221 8.0 23.7 1.5 7.8 99 <10 500 680 MAR 06... 1500 14 387 9.0 28.0 2.0 9.4 127 <10 K140 K140 28... 1400 13 343 8.4 25.7 3.0 8.5 111 10 K910 2000 MAY 03... 0830 10 376 7.7 21.2 .5 7.9 94 <10 3900 680 SEP 08... 1100 52 234 8.2 25.5 .6 9.1 118 <10 410 220 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) NOV 09... 84 22.0 6.98 10.2 .5 1.5 85 <1.0 6.0 11.7 MAR 06... -- -- -- -- -- -- 114 -- -- -- 28... 91 23.2 8.17 9.0 .4 1.3 -- <1.0 4.2 8.6 MAY 03... 120 32.8 10.2 28.3 1 2.1 118 <1.0 9.8 41.0 SEP 08... 89 23.5 7.36 12.4 .6 1.5 87 -- 7.1 13.6 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 09... <.1 29.0 138 31.3 5 -- <.01 .9 .04 -- MAR 06... -- -- -- -- 2 .87 .02 .9 .03 -- 28... <.1 28.8 -- -- 17 1.26 .04 1.3 .10 .36 MAY 03... <.1 34.0 229 6.48 1 .99 .01 1.0 .04 -- SEP 08... <.1 26.6 144 20.2 <10 -- <.01 .7 .02 -- NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) NOV 09... <.20 -- -- .040 <3 14.8 E17 <.1 <1 <20 MAR 06... <.20 -- -- .090 -- -- -- -- -- -- 28... .46 1.8 7.8 .210 <3 12.4 <18 <.1 <1 <20 MAY 03... <.20 -- -- .100 <3 17.4 19 <.1 <1 <20 SEP 08... <.20 -- -- .030 -- -- -- -- -- -- 71 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 09... 210 <1 27 <.3 <3 <1 <31 <.01 4 <.02 MAR 06... -- -- -- -- -- -- -- -- -- -- 28... <20 <1 <3 <.3 <3 <1 E20 <.01 <4 .06 MAY 03... 110 <1 33 <.3 <3 <1 <31 <.01 <4 <.02 SEP 08... -- -- -- -- -- -- -- -- -- -- 72 RIO GRANDE DE ARECIBO BASIN 50021030 RIO PELLEJAS ABOVE CENTRAL PELLEJAS, PR LOCATION.--Lat 18°12'17', long 66°42'13", Hydrologic Unit 21010002,0.20 mi (0.32 km) southeast from Escuela Lucas Valdivieso, 2.95 mi (4.75 km) north from Adjuntas Hospital and 2.0 mi (3.22 km) west from Lago Adjuntas. DRAINAGE AREA.--6.83 mi2 (17.7 km2). PERIOD OF RECORD.--May to September 2000. GAGE.--Water-stage recorder. Elevation of gage is 1,148 ft (350 m), from topographic map. REMARKS.--Records fair. Flow regulated by Lago Adjuntas 2.0 mi (3.2 km) west. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e39 49 28 39 2 38 46 33 35 3 40 47 33 31 4 44 46 e32 30 5 46 45 e29 33 6 47 44 26 32 7 49 43 25 e32 8 47 41 24 31 9 38 42 23 31 10 38 43 22 32 11 43 42 22 e33 12 e45 41 22 e33 13 e76 39 22 e35 14 106 38 23 36 15 59 e35 25 e34 16 90 34 28 e36 17 80 e35 27 e47 18 e63 75 e37 26 e102 19 e56 e73 37 24 e79 20 e52 125 35 24 72 21 e51 67 32 24 e45 22 e56 58 30 55 e57 23 e49 56 30 131 e106 24 e48 55 31 29 e75 25 e47 51 32 41 e58 26 e46 50 e28 71 e52 27 e45 48 28 34 e76 28 e43 e45 e27 28 e66 29 e42 42 e27 36 e51 30 e43 46 e27 45 52 31 e40 --- e27 34 --- TOTAL 681 1716 1138 1046 1471 MEAN 48.6 57.2 36.7 33.7 49.0 MAX 63 125 49 131 106 MIN 40 38 27 22 30 AC-FT 1350 3400 2260 2070 2920 CFSM 7.12 8.37 5.37 4.94 7.18 IN. 3.71 9.35 6.20 5.70 8.01 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2000, BY WATER YEAR (WY) MEAN --- 57.2 36.7 33.7 49.0 MAX --- 57.2 36.7 33.7 49.0 (WY) --- 2000 2000 2000 2000 MIN --- 57.2 36.7 33.7 49.0 (WY) --- 2000 2000 2000 2000 SUMMARY STATISTICS FOR 2000 WATER YEAR HIGHEST DAILY MEAN 131 Aug 23 LOWEST DAILY MEAN 22 Aug 10 ANNUAL SEVEN-DAY MINIMUM 23 Aug 8 INSTANTANEOUS PEAK FLOW 1300 Sep 23 INSTANTANEOUS PEAK STAGE 8.09 Sep 23 10 PERCENT EXCEEDS 72 50 PERCENT EXCEEDS 41 90 PERCENT EXCEEDS 26 e Estimated 73 RIO GRANDE DE ARECIBO BASIN 50021030 RIO PELLEJAS ABOVE CENTRAL PELLEJAS, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND Gap indicates missing record 74 RIO GRANDE DE ARECIBO BASIN 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR LOCATION.--Lat 18°14'39", long 66°43'20", Hydrologic Unit 21010001,.40 mi (.64 km) southwest from Escuela Segunda Unidad Salto Arriba,2.17 mi (3.492 km) southwest from Utuado Plaza,1.10 mi (1.770 km) west from Escuela Arenas Abajo and 1.04 mi (1.673 km) northwest from Escuela Puente Blanco. DRAINAGE AREA.--36.0 mi2 (93.24 km2). PERIOD OF RECORD.--August 1989 to May 1999, monthly measurements and peak flow above 5,000 ft3/s (142 m3/s), June 1999 to current year. GAGE.--Water-stage recorder. Elevation of gage is 508 ft (155 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1998 TO SEPTEMBER 1999 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 12 15 112 131 2 35 17 60 e295 3 12 12 45 168 4 5.6 11 39 108 5 4.5 10 186 118 6 3.9 9.5 e57 96 7 3.8 8.9 e37 131 8 23 26 e30 135 9 104 13 e33 197 10 167 9.8 23 129 11 64 8.9 202 114 12 9.4 8.5 85 122 13 6.4 8.0 36 935 14 5.7 8.3 32 416 15 243 12 119 266 16 337 24 228 360 17 201 18 92 232 18 92 12 52 150 19 108 8.5 225 352 20 85 91 192 265 21 34 54 190 193 22 70 14 228 157 23 50 56 153 184 24 29 e26 97 363 25 21 e31 77 216 26 17 e14 71 198 27 15 e13 68 168 28 13 e13 119 245 29 13 131 286 147 30 20 57 191 116 31 26 137 --- TOTAL 1804.3 766.4 3502 6707 MEAN 60.1 24.7 113 224 MAX 337 131 286 935 MIN 3.8 8.0 23 96 AC-FT 3580 1520 6950 13300 CFSM 1.67 .69 3.14 6.21 IN. 1.86 .79 3.62 6.93 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1999 - 1999, BY WATER YEAR (WY) MEAN --- --- --- --- --- --- --- --- 60.1 24.7 113 224 MAX --- --- --- --- --- --- --- --- 60.1 24.7 113 224 (WY) --- --- --- --- --- --- --- --- 1999 1999 1999 1999 MIN --- --- --- --- --- --- --- --- 60.1 24.7 113 224 (WY) --- --- --- --- --- --- --- --- 1999 1999 1999 1999 SUMMARY STATISTICS FOR 1999 WATER YEAR HIGHEST DAILY MEAN 935 Sep 13 LOWEST DAILY MEAN 3.8 Jun 7 ANNUAL SEVEN-DAY MINIMUM 9.8 Jul 9 INSTANTANEOUS PEAK FLOW 5330 Sep 13 INSTANTANEOUS PEAK STAGE 8.54 Sep 13 10 PERCENT EXCEEDS 240 50 PERCENT EXCEEDS 66 90 PERCENT EXCEEDS 9.0 e Estimated 75 RIO GRANDE DE ARECIBO BASIN 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR--Continued O N D 1998 J F M A M J J A S 1999 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND Gap indicates missing record 76 RIO GRANDE DE ARECIBO BASIN 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR--Continued DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 111 245 e113 e25 13 6.9 14 8.4 e36 59 e5.7 195 2 109 367 e194 e23 10 6.7 6.2 6.8 e36 54 e4.2 158 3 103 352 e165 e24 9.9 6.6 6.8 14 e33 56 e4.4 109 4 99 252 e129 e24 14 6.5 6.2 129 e32 56 e4.2 91 5 e101 258 e125 e62 15 6.5 5.7 48 e32 53 e4.2 90 6 e125 e195 e110 e50 16 6.4 5.7 413 e31 51 e4.2 89 7 e100 148 e98 e26 17 6.4 5.6 245 e31 50 e4.3 82 8 e188 135 e106 e23 12 6.3 5.8 430 e31 47 e4.2 74 9 e114 145 e78 e20 9.6 6.3 20 283 e30 54 e4.3 67 10 e110 119 e76 e18 9.1 6.2 23 127 e30 51 e4.7 66 11 e395 116 e58 e17 8.6 6.1 13 126 e46 54 4.7 63 12 e277 108 e50 e19 9.1 6.1 7.6 84 e90 e48 4.4 61 13 e276 102 e43 e14 10 6.1 6.7 50 e239 e41 4.1 53 14 e160 98 e38 e14 9.7 5.9 6.3 45 329 e38 4.1 75 15 e136 e96 e39 e17 9.1 5.7 6.0 38 156 e31 4.2 79 16 e149 e178 e38 e36 8.3 5.7 6.0 29 245 e26 5.2 142 17 e304 393 e40 e19 8.0 5.7 6.1 e188 152 e26 5.3 135 18 e347 711 e38 e15 7.9 5.7 6.0 e121 101 e29 4.4 840 19 e180 705 e38 e13 8.0 5.6 5.8 e74 86 e25 4.6 396 20 e175 396 e36 e14 8.0 5.5 7.3 e62 225 e24 4.3 397 21 e140 238 e33 e14 8.0 6.1 49 e59 141 e16 4.2 264 22 e123 177 e34 12 7.9 6.1 19 e54 83 e14 338 307 23 e106 165 e29 14 32 5.8 8.3 e60 73 e12 2210 339 24 e83 146 e30 19 12 6.3 6.9 e68 73 e12 239 258 25 e139 134 e26 14 10 6.0 6.2 e56 70 e11 265 194 26 89 124 e24 34 8.0 7.2 5.7 e52 69 e8.8 354 160 27 62 115 e25 28 7.5 7.4 5.6 e49 59 e7.4 168 244 28 131 108 e24 19 7.2 5.8 5.5 e50 51 e6.3 95 229 29 91 e102 e105 18 7.1 12 5.7 e41 46 e5.7 110 142 30 124 e169 e34 19 --- 9.8 5.7 e37 50 e5.1 185 130 31 706 --- e27 17 --- 9.7 --- e38 --- e4.5 132 --- TOTAL 5353 6597 2003 681 312.0 205.1 287.4 3085.2 2706 975.8 4189.9 5529 MEAN 173 220 64.6 22.0 10.8 6.62 9.58 99.5 90.2 31.5 135 184 MAX 706 711 194 62 32 12 49 430 329 59 2210 840 MIN 62 96 24 12 7.1 5.5 5.5 6.8 30 4.5 4.1 53 AC-FT 10620 13090 3970 1350 619 407 570 6120 5370 1940 8310 10970 CFSM 4.80 6.11 1.79 .61 .30 .18 .27 2.76 2.51 .87 3.75 5.12 IN. 5.53 6.82 2.07 .70 .32 .21 .30 3.19 2.80 1.01 4.33 5.71 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1999 - 2000, BY WATER YEAR (WY) MEAN 173 220 64.6 22.0 10.8 6.62 9.58 99.5 75.2 28.1 124 204 MAX 173 220 64.6 22.0 10.8 6.62 9.58 99.5 90.2 31.5 135 224 (WY) 2000 2000 2000 2000 2000 2000 2000 2000 2000 2000 2000 1999 MIN 173 220 64.6 22.0 10.8 6.62 9.58 99.5 60.1 24.7 113 184 (WY) 2000 2000 2000 2000 2000 2000 2000 2000 1999 1999 1999 2000 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1999 - 2000 ANNUAL TOTAL 31924.4 ANNUAL MEAN 87.2 87.2 HIGHEST ANNUAL MEAN 87.2 2000 LOWEST ANNUAL MEAN 87.2 2000 HIGHEST DAILY MEAN 935 Sep 13 2210 Aug 23 2210 Aug 23 2000 LOWEST DAILY MEAN 3.8 Jun 7 4.1 Aug 13 3.8 Jun 7 1999 ANNUAL SEVEN-DAY MINIMUM 9.8 Jul 9 4.2 Aug 2 4.2 Aug 2 2000 INSTANTANEOUS PEAK FLOW 8860 Oct 31 45600 Sep 22 1998 INSTANTANEOUS PEAK STAGE 10.41 Oct 31 19.72 Sep 22 1998 ANNUAL RUNOFF (AC-FT) 63320 63190 ANNUAL RUNOFF (CFSM) 2.42 2.42 ANNUAL RUNOFF (INCHES) 32.99 32.92 10 PERCENT EXCEEDS 266 232 233 50 PERCENT EXCEEDS 104 38 41 90 PERCENT EXCEEDS 12 5.7 6.0 e Estimated 77 RIO GRANDE DE ARECIBO BASIN 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR--Continued O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 78 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR LOCATION.--Lat 18°18'07", long 66°42'15", Hydrologic Unit 21010001, 2.4 mi (3.9 km) north of Utuado Plaza, 3.4 mi (5.5 km) southwest from Dos Bocas Dam, 3.5 mi (5.6 km) northwest from Caonillas Dam. DRAINAGE AREA.--65.62 mi2 (170 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--April 1996 to September 1998, June 1999 to current year. GAGE.--Water-stage recorder. Elevation of gage is 295.28 ft (90 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1998 TO SEPTEMBER 1999 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 95 196 252 2 100 192 615 3 99 165 864 4 81 161 331 5 77 392 294 6 72 189 368 7 80 148 382 8 154 144 479 9 138 135 521 10 e301 117 120 333 11 408 112 317 314 12 153 114 240 237 13 113 110 185 1280 14 84 107 248 697 15 414 116 241 618 16 589 175 425 674 17 493 128 255 531 18 520 134 174 317 19 444 116 471 928 20 549 165 289 595 21 334 296 325 583 22 358 190 509 449 23 294 263 428 447 24 210 229 276 775 25 153 171 284 514 26 128 164 171 446 27 109 149 142 309 28 97 135 188 465 29 103 191 465 302 30 106 193 327 289 31 138 241 --- TOTAL 5960 4409 8043 15209 MEAN 284 142 259 507 MAX 589 296 509 1280 MIN 84 72 120 237 AC-FT 11820 8750 15950 30170 CFSM 4.33 2.17 3.95 7.73 IN. 3.38 2.50 4.56 8.62 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1996 - 1999, BY WATER YEAR (WY) MEAN 198 163 85.6 79.6 65.0 50.9 56.9 105 83.1 112 206 555 MAX 224 242 118 120 83.5 68.0 67.7 153 120 184 393 1100 (WY) 1997 1997 1997 1997 1997 1997 1998 1998 1996 1998 1998 1998 MIN 172 84.8 53.0 39.5 46.6 33.8 46.2 50.8 40.8 36.6 77.0 87.3 (WY) 1998 1998 1998 1998 1998 1998 1997 1997 1997 1997 1997 1997 SUMMARY STATISTICS FOR 1998 CALENDAR YEAR FOR 1999 WATER YEAR WATER YEARS 1996 - 1999 ANNUAL MEAN 150 HIGHEST ANNUAL MEAN 201 1998 LOWEST ANNUAL MEAN 99.6 1997 HIGHEST DAILY MEAN 17900 Sep 22 1280 Sep 13 17900 Sep 22 1998 LOWEST DAILY MEAN 22 Mar 20 72 Jul 6 22 Mar 20 1998 ANNUAL SEVEN-DAY MINIMUM 23 Mar 19 86 Jul 1 23 Mar 19 1998 INSTANTANEOUS PEAK FLOW 5260 Sep 13 76400 Sep 22 1998 INSTANTANEOUS PEAK STAGE 11.17 Sep 13 32.92 Sep 22 1998 INSTANTANEOUS LOW FLOW 20 Mar 24 1998 ANNUAL RUNOFF (AC-FT) 108900 ANNUAL RUNOFF (CFSM) 2.29 ANNUAL RUNOFF (INCHES) 31.14 10 PERCENT EXCEEDS 450 569 336 50 PERCENT EXCEEDS 69 241 79 90 PERCENT EXCEEDS 30 106 37 e Estimated 79 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued O N D 1998 J F M A M J J A S 1999 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND Gap indicates missing record 80 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 229 1050 244 192 109 85 169 69 66 94 74 192 2 216 1450 617 186 107 82 99 57 65 100 75 178 3 187 1530 452 225 108 79 93 187 64 90 65 120 4 171 1390 308 198 108 77 79 531 66 87 68 126 5 170 1280 398 232 109 79 68 303 67 87 62 159 6 229 1040 319 273 109 78 59 545 67 86 57 138 7 277 892 314 205 111 78 57 453 68 144 54 118 8 359 719 304 203 102 75 61 957 67 89 53 131 9 229 637 273 192 100 74 74 845 64 97 50 131 10 225 438 237 184 99 72 192 297 68 86 53 143 11 583 376 207 179 98 72 117 667 84 83 51 125 12 386 e333 193 168 94 74 83 368 101 82 49 122 13 563 e316 181 155 95 74 77 181 288 76 47 117 14 444 e351 174 166 97 69 88 121 413 71 48 118 15 535 432 181 217 92 62 68 102 209 68 52 131 16 562 467 190 259 83 61 67 87 348 62 57 182 17 935 946 196 156 78 60 68 461 212 66 59 168 18 829 1780 181 131 74 61 69 231 122 74 52 807 19 602 1790 179 120 69 63 76 136 102 70 54 375 20 615 1470 189 125 79 60 100 118 245 121 49 358 21 667 966 180 122 77 60 400 106 230 72 48 298 22 640 792 191 119 e78 65 172 93 126 63 192 618 23 532 508 179 117 e208 56 92 102 110 62 2080 580 24 448 385 167 126 e178 60 66 122 103 64 233 401 25 605 297 156 124 e127 54 56 97 99 68 290 285 26 458 274 162 158 e93 70 53 87 108 64 424 224 27 371 264 177 139 91 68 51 82 95 61 199 344 28 459 255 170 117 88 54 49 89 87 60 109 268 29 386 257 355 118 85 86 49 80 84 59 122 180 30 594 299 239 115 --- 247 48 77 84 59 150 166 31 1670 --- 199 111 --- 124 --- 71 --- 57 133 --- TOTAL 15176 22984 7512 5132 2946 2379 2800 7722 3912 2422 5109 7303 MEAN 490 766 242 166 102 76.7 93.3 249 130 78.1 165 243 MAX 1670 1790 617 273 208 247 400 957 413 144 2080 807 MIN 170 255 156 111 69 54 48 57 64 57 47 117 AC-FT 30100 45590 14900 10180 5840 4720 5550 15320 7760 4800 10130 14490 CFSM 7.46 11.7 3.69 2.52 1.55 1.17 1.42 3.80 1.99 1.19 2.51 3.71 IN. 8.60 13.03 4.26 2.91 1.67 1.35 1.59 4.38 2.22 1.37 2.90 4.14 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1996 - 2000, BY WATER YEAR (WY) MEAN 295 364 138 108 77.5 59.5 69.1 141 94.9 105 197 493 MAX 490 766 242 166 102 76.7 93.3 249 130 184 393 1100 (WY) 2000 2000 2000 2000 2000 2000 2000 2000 2000 1998 1998 1998 MIN 172 84.8 53.0 39.5 46.6 33.8 46.2 50.8 40.8 36.6 77.0 87.3 (WY) 1998 1998 1998 1998 1998 1998 1997 1997 1997 1997 1997 1997 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1996 - 2000 ANNUAL TOTAL 85397 ANNUAL MEAN 233 178 HIGHEST ANNUAL MEAN 233 2000 LOWEST ANNUAL MEAN 99.6 1997 HIGHEST DAILY MEAN 1790 Nov 19 2080 Aug 23 17900 Sep 22 1998 LOWEST DAILY MEAN 72 Jul 6 47 Aug 13 22 Mar 20 1998 ANNUAL SEVEN-DAY MINIMUM 86 Jul 1 50 Aug 9 23 Mar 19 1998 INSTANTANEOUS PEAK FLOW 8020 Oct 31 76400 Sep 22 1998 INSTANTANEOUS PEAK STAGE 12.65 Oct 31 32.92 Sep 22 1998 INSTANTANEOUS LOW FLOW 20 Mar 24 1998 ANNUAL RUNOFF (AC-FT) 169400 129000 ANNUAL RUNOFF (CFSM) 3.56 2.71 ANNUAL RUNOFF (INCHES) 48.41 36.87 10 PERCENT EXCEEDS 741 538 386 50 PERCENT EXCEEDS 294 122 88 90 PERCENT EXCEEDS 119 61 40 e Estimated 81 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 82 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- April, 1996 to current water year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: April, 1996 to current water year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1996. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediments samples were collected by hydrologic technician and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 10,600 mg/L September 10, 1996; Minimum daily mean, 3 mg/L August 6, 1996. SEDIMENT LOADS: Maximum daily mean, 768,000 tons (e698,000 tonnes) September 22,1998; Minimum daily mean, 0.50 ton (0.45 tonne) August 6, 1996. EXTREMES FOR CURRENT YEAR 2000.-- SEDIMENT CONCENTRATION: Maximum daily mean, 7,930 mg/L August 23, 2000; Minimum daily mean, 14 mg/L September 13, 2000. SEDIMENT LOADS: Maximum daily mean, 76,500 tons (69,401 tonnes) October 31, 1999; Minimum daily mean, 2.1 tons (1.9 tonnes) April 30, 2000. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 229 229 142 1050 793 2240 244 251 183 2 216 182 106 1450 2880 21700 617 1720 5040 3 187 111 56 1530 2440 11800 452 377 564 4 171 77 35 1390 1620 6140 308 126 106 5 170 91 42 1280 430 1460 398 83 88 6 229 318 227 1040 249 707 319 57 50 7 277 772 936 892 139 336 314 46 39 8 359 819 1560 719 93 181 304 41 34 9 229 168 110 637 128 220 273 50 37 10 225 116 71 438 156 184 237 61 39 11 583 1870 10000 376 114 116 207 69 38 12 386 1120 1430 e333 e81 e73 193 76 39 13 563 1070 1750 e316 e74 e63 181 83 41 14 444 895 1200 e351 e75 e71 174 89 42 15 535 1080 2330 432 687 1040 181 86 42 16 562 1280 2610 467 866 1660 190 63 32 17 935 3060 16900 946 2530 7950 196 48 25 18 829 2130 6660 1780 3950 22900 181 47 23 19 602 707 1230 1790 890 4810 179 48 23 20 615 793 1760 1470 210 830 189 46 24 21 667 1040 2040 966 186 485 180 39 19 22 640 290 541 792 153 330 191 33 17 23 532 107 154 508 93 129 179 28 14 24 448 81 98 385 61 64 167 26 12 25 605 1000 2710 297 61 49 156 24 10 26 458 500 692 274 62 46 162 23 10 27 371 85 86 264 63 45 177 22 10 28 459 615 1260 255 65 45 170 21 9.5 29 386 943 1010 257 65 45 355 639 797 30 594 1280 3490 299 348 535 239 88 62 31 1670 7120 76500 --- --- --- 199 18 9.8 TOTAL 15176 --- 137736 22984 --- 86254 7512 --- 7479.3 83 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 192 15 7.9 109 51 15 85 96 22 2 186 15 7.3 107 51 15 82 68 15 3 225 218 166 108 52 15 79 49 10 4 198 190 102 108 50 15 77 39 8.0 5 232 312 311 109 48 14 79 49 10 6 273 355 297 109 46 13 78 63 13 7 205 94 54 111 44 13 78 75 16 8 203 42 23 102 42 12 75 65 13 9 192 40 21 100 39 11 74 55 11 10 184 38 19 99 31 8.4 72 51 9.8 11 179 33 16 98 25 6.5 72 67 13 12 168 28 13 94 26 6.6 74 91 18 13 155 24 10 95 70 18 74 121 24 14 166 22 9.9 97 198 52 69 151 28 15 217 152 178 92 470 116 62 186 31 16 259 175 147 83 555 125 61 197 33 17 156 40 17 78 597 125 60 105 17 18 131 24 8.4 74 634 126 61 51 8.4 19 120 17 5.5 69 525 98 63 36 6.1 20 125 23 7.9 79 397 85 60 89 14 21 122 34 11 77 300 62 60 240 39 22 119 44 14 e78 e226 e48 65 614 106 23 117 40 13 e208 e502 e596 56 784 119 24 126 34 12 e178 e600 e320 60 803 130 25 124 30 10 e127 e475 e173 54 789 115 26 158 180 105 e93 e409 e103 70 411 75 27 139 306 118 91 269 66 68 339 63 28 117 107 34 88 190 45 54 313 46 29 118 78 25 85 135 31 86 311 74 30 115 62 19 --- --- --- 247 1420 1810 31 111 51 15 --- --- --- 124 1530 532 TOTAL 5132 --- 1796.9 2946 --- 2333.5 2379 --- 3429.3 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 169 725 337 69 81 23 66 47 8.4 2 99 337 91 57 85 13 65 24 4.2 3 93 243 61 187 462 503 64 21 3.7 4 79 220 47 531 2060 6550 66 20 3.6 5 68 198 36 303 1440 1460 67 21 3.7 6 59 179 29 545 2000 12200 67 31 5.5 7 57 161 25 453 1650 4070 68 47 8.7 8 61 146 24 957 3870 21800 67 71 13 9 74 192 51 845 1780 5540 64 90 15 10 192 653 463 297 326 270 68 112 21 11 117 756 240 667 2270 10500 84 132 30 12 83 623 140 368 326 401 101 177 62 13 77 515 107 181 210 101 288 760 1070 14 88 434 103 121 280 91 413 1390 3070 15 68 366 68 102 220 63 209 563 355 16 67 317 57 87 111 26 348 946 1590 17 68 334 62 461 1720 4620 212 291 195 18 69 368 69 231 602 443 122 158 52 19 76 392 80 136 169 63 102 128 35 20 100 351 94 118 120 39 245 626 1500 21 400 2400 9410 106 94 27 230 356 289 22 172 956 457 93 102 26 126 141 48 23 92 654 164 102 114 31 110 119 35 24 66 465 84 122 226 107 103 139 39 25 56 383 58 97 182 48 99 115 31 26 53 320 46 87 150 35 108 98 29 27 51 235 32 82 132 29 95 105 27 28 49 98 13 89 156 38 87 115 27 29 49 38 4.9 80 193 42 84 122 28 30 48 16 2.0 77 200 42 84 116 26 31 --- --- --- 71 101 19 --- --- --- TOTAL 2800 --- 12454.9 7722 --- 69220 3912 --- 8624.8 84 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 94 108 27 74 174 39 192 457 470 2 100 220 72 75 182 38 178 360 202 3 90 77 19 65 127 22 120 192 62 4 87 52 12 68 151 28 126 302 131 5 87 36 8.5 62 259 43 159 379 204 6 86 32 7.4 57 340 52 138 330 125 7 144 202 167 54 467 68 118 98 32 8 89 60 15 53 580 84 131 132 68 9 97 110 36 50 510 69 131 332 124 10 86 44 10 53 435 62 143 235 89 11 83 61 14 51 407 56 125 115 39 12 82 139 31 49 510 67 122 48 16 13 76 101 21 47 655 83 117 14 4.5 14 71 67 13 48 799 105 118 24 7.6 15 68 46 8.4 52 656 92 131 34 12 16 62 51 8.6 57 491 75 182 403 366 17 66 63 11 59 401 64 168 251 127 18 74 76 15 52 446 62 807 671 3070 19 70 77 14 54 509 74 375 659 1520 20 121 274 160 49 555 74 358 953 1200 21 72 143 28 48 339 44 298 718 756 22 63 139 24 192 875 6730 618 2600 10200 23 62 152 25 2080 7930 72400 580 1390 2760 24 64 166 29 233 110 69 401 538 650 25 68 182 33 290 522 641 285 161 125 26 64 199 35 424 1260 2400 224 136 82 27 61 208 34 199 626 356 344 969 1200 28 60 187 30 109 275 82 268 387 387 29 59 166 26 122 312 136 180 56 28 30 59 148 23 150 365 193 166 34 15 31 57 136 21 133 391 148 --- --- --- TOTAL 2422 --- 977.9 5109 --- 84456 7303 --- 24072.1 YEAR 85397 438834.7 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- SEDI- SED. CHARGE, MENT, SUSP. INST. SEDI- DIS- SIEVE CUBIC MENT, CHARGE, DIAM. FEET SUS- SUS- % FINER DATE TIME PER PENDED PENDED THAN SECOND (MG/L) (T/DAY) .062 MM (00061) (80154) (80155) (70331) OCT 13... 0910 443 258 309 75 DEC 29... 0825 278 557 418 67 JAN 04... 1020 202 150 82 94 FEB 15... 1115 100 514 139 99 MAR 25... 1710 51 827 114 97 MAY 15... 0915 108 358 104 94 SEP 22... 1509 2950 8370 66800 82 85 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) NOV 17... 0825 971 888 2330 37 47 63 APR 21... 1752 1980 26000 139000 19 26 38 MAY 04... 1814 1690 19200 87700 15 20 28 SEP 19... 1855 1650 4200 18700 23 31 44 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) NOV 17... 73 83 86 93 98 100 100 APR 21... 50 68 80 96 99 100 100 MAY 04... 40 60 73 95 99 100 100 SEP 19... 59 74 83 94 98 100 100 86 RIO GRANDE DE ARECIBO BASIN 50025000 RIO GRANDE DE ARECIBO NEAR UTUADO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°18'11", long 66°41'59", at bridge near Highway 10 at km 56.4, 0.5 mi (0.8 km) downstream from Río de Caguana, and 2.5 mi (4.0 km) north of Utuado plaza. DRAINAGE AREA.--66.0 mi2 (170.9 km2) this excludes 6.0 mi2 (15.5 km2) upstream from Lago Garzas to Río Guayanes in the Río Tallaboa basin. PERIOD OF RECORD.--Water years 1959-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) NOV 04... 1400 494 205 7.7 26.5 77 7.7 97 <10 K16000 2200 FEB 29... 1140 85 289 7.8 22.5 35 8.1 95 <10 K8800 K1300 MAR 29... 1030 86 296 7.0 26.2 140 8.3 104 <10 K15000 7700 MAY 03... 1130 60 298 7.9 27.3 55 8.2 105 <10 2000 370 AUG 16... 1500 59 298 7.7 32.0 150 6.8 95 <10 3800 2400 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) NOV 04... 74 19.7 5.98 9.2 .5 2.4 63 <1.0 18.1 8.2 FEB 29... -- -- -- -- -- -- 93 -- -- -- MAR 29... 110 28.5 8.68 13.8 .6 1.9 -- <1.0 31.0 14.0 MAY 03... 110 30.2 8.90 15.0 .6 1.9 98 <1.0 29.9 15.4 AUG 16... 100 27.8 8.25 13.9 .6 1.8 92 -- 27.7 15.4 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 04... .1 25.4 127 169 110 1.19 .01 1.2 .05 .26 FEB 29... -- -- -- -- 36 1.26 .04 1.3 .16 .30 MAR 29... <.1 30.4 -- -- 316 .98 .02 1.0 .09 .39 MAY 03... <.1 30.8 191 30.7 105 .78 .03 .8 .09 .13 AUG 16... .1 29.0 179 28.6 369 .71 .08 .8 .20 .39 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) NOV 04... .31 1.5 6.7 .170 <3 59.0 E10 E.1 3 24 FEB 29... .46 1.8 7.8 .170 -- -- -- -- -- -- MAR 29... .48 1.5 6.6 .420 <3 134 E15 .2 4 87 MAY 03... .22 1.0 4.6 .150 <3 74.4 E17 <.1 2 52 AUG 16... .59 1.4 6.1 .360 -- -- -- -- -- -- 87 RIO GRANDE DE ARECIBO BASIN 50025000 RIO GRANDE DE ARECIBO NEAR UTUADO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 04... 3750 3 220 <.3 <3 <1 E18 <.01 8 <.04 FEB 29... -- -- -- -- -- -- -- -- -- -- MAR 29... 6860 6 536 <.3 <3 <1 49 <.01 <4 <.04 MAY 03... 2600 2 192 <.3 <3 <1 <31 <.01 <4 <.04 AUG 16... -- -- -- -- -- -- -- -- -- -- 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR LOCATION.--Lat 18°12'48", long 66°33'49", Hydrologic Unit 21010002, 2.0 mi (3.2 km) southeast of Jayuya, 1.4 mi (2.2 km) northeast of Hacienda Gripiñas. DRAINAGE AREA.--9.25 mi2 (23.96 km2). PERIOD OF RECORD.--October 1989 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,706 ft (520 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1998 TO SEPTEMBER 1999 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e62 79 55 19 18 11 e7.6 e14 e45 e15 e25 e40 2 e56 85 90 18 20 11 e9.4 e11 e84 e24 e17 e56 3 e48 80 77 18 14 10 e41 e10 e58 e17 e10 e45 4 e42 66 56 16 13 9.7 e27 e9.5 e34 e14 e11 e29 5 e37 61 48 16 12 9.5 e12 e14 e51 e13 e50 e58 6 e32 57 44 16 12 9.4 e9.7 e12 e32 e12 e25 e84 7 e35 59 40 15 12 9.3 e10 e10 e22 e11 e16 e110 8 e58 52 37 15 11 10 e15 e13 e57 e20 e11 e84 9 e56 50 35 14 11 9.9 e17 e14 e76 e16 e8.2 e140 10 e40 52 33 15 11 10 e20 e11 e84 e12 e7.0 e80 11 e37 49 32 15 11 9.3 e11 e39 e68 e11 e6.0 e60 12 e33 87 31 13 11 11 e10 e13 e58 e10 e6.2 e45 13 e28 76 30 13 11 10 e9.2 e12 e41 e10 e12 e110 14 e32 69 29 12 15 8.6 e8.6 e14 e31 e10 e27 e120 15 e35 69 28 21 16 8.3 e8.0 e10 e40 e9.8 e16 e80 16 e52 60 27 21 15 8.1 e7.4 e9.0 e58 e9.0 e18 e60 17 e40 49 26 16 13 8.0 e7.2 e8.4 e58 e11 e17 e48 18 e30 43 25 13 12 7.9 e7.2 e8.2 e52 e8.0 e7.0 e42 19 e25 40 25 13 11 e24 e7.0 e7.6 e40 e7.0 e13 e160 20 e21 38 27 12 11 e15 e6.8 e7.2 e34 e7.4 e17 e120 21 e25 36 25 12 11 e22 e7.0 e7.0 e28 e14 e22 e70 22 54 34 23 12 11 e12 e10 e10 e25 e7.6 e50 e48 23 33 35 23 12 11 e7.5 e17 e13 e23 e11 e34 e42 24 27 35 22 11 11 e7.1 e29 e9.1 e20 e16 e19 e43 25 29 31 21 11 11 e9.3 e35 e8.7 e18 e6.0 e11 e40 26 102 29 20 11 12 e8.9 e87 e9.5 e17 e5.4 e9.6 e39 27 223 46 19 12 12 e6.8 e25 e12 e16 e5.6 e14 e35 28 142 50 22 18 11 e6.7 e16 e14 e15 e6.0 e11 e50 29 96 42 27 12 --- e6.6 e39 e17 e38 e7.4 e180 e40 30 95 39 21 11 --- e7.3 e23 e31 e21 e7.0 e110 e35 31 101 --- 20 11 --- e7.8 --- e44 --- e6.0 e70 --- TOTAL 1726 1598 1038 444 350 312.0 539.1 422.2 1244 339.2 850.0 2013 MEAN 55.7 53.3 33.5 14.3 12.5 10.1 18.0 13.6 41.5 10.9 27.4 67.1 MAX 223 87 90 21 20 24 87 44 84 24 180 160 MIN 21 29 19 11 11 6.6 6.8 7.0 15 5.4 6.0 29 AC-FT 3420 3170 2060 881 694 619 1070 837 2470 673 1690 3990 CFSM 6.02 5.76 3.62 1.55 1.35 1.09 1.94 1.47 4.48 1.18 2.96 7.25 IN. 6.94 6.43 4.17 1.79 1.41 1.25 2.17 1.70 5.00 1.36 3.42 8.10 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 1999, BY WATER YEAR (WY) MEAN 42.2 26.3 14.4 17.8 16.6 11.4 22.8 37.9 25.1 16.4 28.6 101 MAX 72.0 53.3 33.5 48.1 44.4 17.8 46.8 98.6 41.5 50.9 74.5 365 (WY) 1996 1999 1999 1992 1996 1998 1998 1995 1999 1996 1998 1996 MIN 11.6 10.0 5.41 4.13 4.67 4.79 5.95 5.35 5.30 2.83 9.82 10.8 (WY) 1992 1994 1998 1995 1994 1994 1994 1990 1997 1994 1994 1994 SUMMARY STATISTICS FOR 1998 CALENDAR YEAR FOR 1999 WATER YEAR WATER YEARS 1989 - 1999 ANNUAL TOTAL 20285.5 10875.5 ANNUAL MEAN 55.6 29.8 30.0 HIGHEST ANNUAL MEAN 64.0 1996 LOWEST ANNUAL MEAN 10.9 1994 HIGHEST DAILY MEAN 2460 Sep 21 223 Oct 27 4700 Sep 10 1996 LOWEST DAILY MEAN 3.6 Jan 4 5.4 Jul 26 2.3 Jul 27 1994 ANNUAL SEVEN-DAY MINIMUM 3.9 Jan 3 6.2 Jul 25 2.5 Jul 23 1994 INSTANTANEOUS PEAK FLOW 2260 Oct 27 18500 Sep 21 1998 INSTANTANEOUS PEAK STAGE 11.49 Oct 27 20.00 Sep 21 1998 INSTANTANEOUS LOW FLOW 2.1 Jul 26 1994 ANNUAL RUNOFF (AC-FT) 40240 21570 21750 ANNUAL RUNOFF (CFSM) 6.01 3.22 3.25 ANNUAL RUNOFF (INCHES) 81.58 43.74 44.10 10 PERCENT EXCEEDS 97 61 55 50 PERCENT EXCEEDS 28 18 13 90 PERCENT EXCEEDS 7.3 8.2 4.7 e Estimated 89 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR--Continued O N D 1998 J F M A M J J A S 1999 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 90 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA--Continued DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e46 67 44 24 13 13 9.1 6.1 12 7.4 7.3 60 2 e42 64 69 24 13 12 8.8 6.1 12 8.5 7.0 51 3 e38 59 93 28 13 12 8.9 104 11 8.1 5.9 42 4 e36 51 49 38 13 12 8.4 95 11 7.3 5.8 51 5 e36 54 67 33 13 12 8.0 53 11 6.8 5.8 74 6 e37 47 78 30 12 12 7.9 29 10 8.3 5.1 69 7 e41 41 59 29 12 12 7.8 60 9.8 7.4 5.8 e50 8 e47 37 58 26 12 12 7.7 80 9.5 6.8 6.4 e38 9 e37 35 48 24 11 11 7.4 170 9.3 6.6 5.3 e47 10 e34 35 42 23 11 11 13 72 9.3 6.2 5.9 e72 11 e70 33 37 22 11 11 11 75 9.2 6.2 5.7 e41 12 e47 31 34 21 11 11 7.8 58 14 6.0 5.3 e30 13 e48 33 32 22 10 10 7.3 38 35 5.9 5.0 e26 14 e36 32 30 22 10 10 7.0 28 29 5.8 11 e26 15 e40 61 28 32 9.9 10 6.8 23 17 5.7 9.3 e29 16 e47 87 27 51 9.8 9.8 6.7 20 41 5.5 8.6 e50 17 e76 264 28 24 9.4 9.7 7.2 32 22 6.1 6.3 e63 18 e63 402 26 21 9.4 9.6 13 25 15 6.1 5.3 e436 19 e41 388 27 19 9.7 9.5 15 19 12 5.5 5.3 e235 20 65 240 27 18 9.6 9.2 14 17 14 25 5.1 e152 21 68 149 27 18 9.2 9.2 12 16 13 12 4.7 e100 22 67 109 31 17 9.3 9.5 8.3 15 11 7.2 101 e185 23 55 86 29 17 77 9.1 7.2 35 9.7 6.5 293 e210 24 48 70 28 16 26 10 6.6 19 11 7.1 68 e126 25 69 59 27 16 30 9.4 6.4 17 10 7.0 64 e71 26 51 52 25 19 18 9.1 6.4 16 9.2 6.1 49 e80 27 43 45 24 16 17 9.1 6.2 14 8.6 5.7 39 e187 28 60 40 25 15 14 10 6.2 15 8.1 5.6 35 e78 29 46 37 47 15 13 19 6.1 17 7.8 6.0 32 58 30 82 37 28 15 --- 10 6.1 15 7.6 6.3 44 51 31 117 --- 25 14 --- 9.4 --- 13 --- 5.6 38 --- TOTAL 1633 2745 1219 709 436.3 332.6 254.3 1202.2 409.1 226.3 894.9 2788 MEAN 52.7 91.5 39.3 22.9 15.0 10.7 8.48 38.8 13.6 7.30 28.9 92.9 MAX 117 402 93 51 77 19 15 170 41 25 293 436 MIN 34 31 24 14 9.2 9.1 6.1 6.1 7.6 5.5 4.7 26 AC-FT 3240 5440 2420 1410 865 660 504 2380 811 449 1780 5530 CFSM 5.69 9.89 4.25 2.47 1.63 1.16 .92 4.19 1.47 .79 3.12 10.0 IN. 6.57 11.04 4.90 2.85 1.75 1.34 1.02 4.83 1.65 .91 3.60 11.21 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 2000, BY WATER YEAR (WY) MEAN 43.2 32.2 16.7 18.2 16.5 11.3 21.5 38.0 24.1 15.6 28.6 101 MAX 72.0 91.5 39.3 48.1 44.4 17.8 46.8 98.6 41.5 50.9 74.5 365 (WY) 1996 2000 2000 1992 1996 1998 1998 1995 1999 1996 1998 1996 MIN 11.6 10.0 5.41 4.13 4.67 4.79 5.95 5.35 5.30 2.83 9.82 10.8 (WY) 1992 1994 1998 1995 1994 1994 1994 1990 1997 1994 1994 1994 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1989 - 2000 ANNUAL TOTAL 12110.5 12849.7 ANNUAL MEAN 33.2 35.1 30.5 HIGHEST ANNUAL MEAN 64.0 1996 LOWEST ANNUAL MEAN 10.9 1994 HIGHEST DAILY MEAN 402 Nov 18 436 Sep 18 4700 Sep 10 1996 LOWEST DAILY MEAN 5.4 Jul 26 4.7 Aug 21 2.3 Jul 27 1994 ANNUAL SEVEN-DAY MINIMUM 6.2 Jul 25 5.6 Aug 7 2.5 Jul 23 1994 INSTANTANEOUS PEAK FLOW 1910 Aug 22 18500 Sep 21 1998 INSTANTANEOUS PEAK STAGE 9.53 Aug 22 20.00 Sep 21 1998 INSTANTANEOUS LOW FLOW 2.1 Jul 26 1994 ANNUAL RUNOFF (AC-FT) 24020 25490 22080 ANNUAL RUNOFF (CFSM) 3.59 3.80 3.30 ANNUAL RUNOFF (INCHES) 48.70 51.68 44.78 10 PERCENT EXCEEDS 68 70 57 50 PERCENT EXCEEDS 18 18 13 90 PERCENT EXCEEDS 8.2 6.3 4.8 e Estimated 91 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA--Continued O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 92 RIO GRANDE DE ARECIBO BASIN 50025850 RIO JAUCA AT PASO PALMA, PR LOCATION.--Lat 18°12'50", long 66°38'44", Hydrologic Unit 21010001, 5.13 mi (8.2 km) southeast from Utuado Plaza,4.5 mi (7.24 km) south of Caonillas Dam and 6.15 mi (9.89 km),northeast from Adjuntas Plaza. DRAINAGE AREA.--6.89 mi2 (17.84 km2). PERIOD OF RECORD.--May to September 2000. GAGE.--Water-stage recorder. Elevation of gage is 358 ft (109 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e7.7 5.7 e5.7 66 2 e7.4 6.3 e5.1 43 3 e7.2 5.9 e4.6 29 4 e6.8 5.5 e4.4 27 5 e6.5 5.2 e4.3 43 6 e6.2 5.2 e4.1 39 7 e6.0 5.3 e4.2 e30 8 e6.0 5.1 e4.2 e24 9 e6.0 5.2 e4.0 e21 10 e6.0 5.5 e4.7 e35 11 e6.0 5.7 4.5 e26 12 e8.2 5.7 4.2 e21 13 e13 5.5 4.4 e18 14 e13 5.6 5.2 e19 15 e11 e5.6 5.7 23 16 e25 e5.3 6.3 28 17 e13 e5.4 5.8 31 18 e13 e7.9 e5.5 5.0 184 19 e12 e5.8 e5.4 5.1 64 20 e11 e13 e9.6 5.7 62 21 e12 e7.8 e6.9 6.0 48 22 e11 e5.9 e5.5 22 46 23 e13 6.4 e5.2 235 47 24 e14 6.0 e5.5 34 53 25 e10 6.3 e5.6 36 42 26 e9.8 6.3 e5.0 38 51 27 e9.0 6.0 e4.8 29 54 28 e8.5 5.8 e4.9 20 50 29 e10 5.6 e4.8 20 39 30 e9.2 5.6 e4.7 27 40 31 e8.2 --- e4.6 23 --- TOTAL 150.7 243.4 171.7 587.2 1303 MEAN 10.8 8.11 5.54 18.9 43.4 MAX 14 25 9.6 235 184 MIN 8.2 5.6 4.6 4.0 18 AC-FT 299 483 341 1160 2580 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2000, BY WATER YEAR (WY) MEAN --- --- --- --- --- --- --- --- 8.11 5.54 18.9 43.4 MAX --- --- --- --- --- --- --- --- 8.11 5.54 18.9 43.4 (WY) --- --- --- --- --- --- --- --- 2000 2000 2000 2000 MIN --- --- --- --- --- --- --- --- 8.11 5.54 18.9 43.4 (WY) --- --- --- --- --- --- --- --- 2000 2000 2000 2000 SUMMARY STATISTICS FOR 2000 WATER YEAR HIGHEST DAILY MEAN 235 Aug 23 LOWEST DAILY MEAN 4.0 Aug 9 ANNUAL SEVEN-DAY MINIMUM 4.3 Aug 3 INSTANTANEOUS PEAK FLOW 1120 Aug 23 INSTANTANEOUS PEAK STAGE 5.69 Aug 23 INSTANTANEOUS LOW FLOW 3.7 Aug 12 10 PERCENT EXCEEDS 43 50 PERCENT EXCEEDS 6.9 90 PERCENT EXCEEDS 4.8 e Estimated 93 RIO GRANDE DE ARECIBO BASIN 50025850 RIO JAUCA AT PASO PALMA, PR--Continued O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND Gap indicates missing record 94 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR LOCATION.--Lat 18°13'53", long 66°38'14", Hydrologic Unit 21010001, 3.5 mi (5.6 km) south of Lago Caonillas Dam,4.8 mi (7.72 km) southeast of Utuado Plaza and 2.78 mi (4.47 km) east of Lago Viví Dam. DRAINAGE AREA.--37.94 mi2 (98.26 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1995 to current year. GAGE.--Water-stage recorder. Elevation of gage is 984 ft (300 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e173 e236 161 94 53 38 31 24 39 27 31 188 2 154 e287 233 91 e52 35 32 24 38 29 29 173 3 139 e286 291 116 51 34 32 211 37 28 26 112 4 130 e227 195 130 50 33 28 231 35 26 26 101 5 129 e227 227 118 49 33 27 138 34 25 24 165 6 142 e190 245 121 49 33 26 99 33 26 23 152 7 158 e159 201 115 48 32 25 155 32 28 23 113 8 191 e148 194 100 49 32 26 326 32 25 25 92 9 150 e153 170 92 45 32 25 445 32 25 23 81 10 137 e134 160 85 43 31 31 211 32 24 32 141 11 235 e132 144 80 42 30 42 182 32 24 28 96 12 216 e126 135 77 41 30 26 177 41 24 24 81 13 214 e118 127 79 41 30 24 110 60 23 23 73 14 164 e112 120 80 42 30 24 87 61 23 28 71 15 169 e109 e115 82 41 30 23 71 52 22 37 76 16 215 e231 e110 156 40 30 23 62 111 22 36 93 17 294 725 e114 84 40 30 25 73 62 23 29 103 18 285 1230 104 e77 40 30 29 79 40 24 25 569 19 206 971 107 e72 41 28 40 58 35 22 26 385 20 264 585 106 e67 41 28 58 54 61 128 25 338 21 266 397 106 e64 39 28 69 57 46 48 23 279 22 275 312 120 e62 40 30 40 54 35 28 177 343 23 226 276 108 e62 208 28 29 66 32 26 1010 373 24 204 250 104 e61 88 32 27 70 31 30 195 298 25 e250 231 102 e62 88 29 25 53 32 31 168 219 26 e234 210 97 e68 57 27 25 51 31 25 173 219 27 e206 191 92 61 52 29 24 47 30 24 138 323 28 e251 183 93 56 44 28 23 45 28 23 109 280 29 e225 166 155 58 40 57 23 49 27 23 103 208 30 e245 164 105 57 --- 42 23 45 27 24 122 193 31 e492 --- 98 54 --- 32 --- 41 --- 23 116 --- TOTAL 6639 8766 4439 2581 1554 991 905 3395 1218 903 2877 5938 MEAN 214 292 143 83.3 53.6 32.0 30.2 110 40.6 29.1 92.8 198 MAX 492 1230 291 156 208 57 69 445 111 128 1010 569 MIN 129 109 92 54 39 27 23 24 27 22 23 71 AC-FT 13170 17390 8800 5120 3080 1970 1800 6730 2420 1790 5710 11780 CFSM 5.64 7.70 3.77 2.19 1.41 .84 .80 2.89 1.07 .77 2.45 5.22 IN. 6.51 8.60 4.35 2.53 1.52 .97 .89 3.33 1.19 .89 2.82 5.82 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1996 - 2000, BY WATER YEAR (WY) MEAN 164 143 80.8 63.1 56.8 38.2 55.4 87.9 74.9 53.2 93.9 343 MAX 248 292 143 89.8 86.0 51.3 112 130 161 117 156 815 (WY) 1999 2000 2000 1997 1996 1996 1998 1998 1999 1996 1998 1998 MIN 72.9 44.2 21.0 19.6 41.9 25.7 17.0 29.1 16.1 15.5 47.9 33.2 (WY) 1997 1998 1998 1998 1997 1997 1997 1997 1997 1997 1996 1997 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1996 - 2000 ANNUAL TOTAL 45825 40206 ANNUAL MEAN 126 110 104 HIGHEST ANNUAL MEAN 137 1998 LOWEST ANNUAL MEAN 49.9 1997 HIGHEST DAILY MEAN 1230 Nov 18 1230 Nov 18 13000 Sep 22 1998 LOWEST DAILY MEAN 22 Jul 26 22 Jul 15 10 Jul 4 1997 ANNUAL SEVEN-DAY MINIMUM 26 Jul 25 23 Jul 13 11 Jul 1 1997 INSTANTANEOUS PEAK FLOW unknown Oct 31 36000 Sep 22 1998 INSTANTANEOUS PEAK STAGE unknown Oct 31 31.15 Sep 22 1998 INSTANTANEOUS LOW FLOW 21 Jul 16 9.5 Jul 6 1997 ANNUAL RUNOFF (AC-FT) 90890 79750 75520 ANNUAL RUNOFF (CFSM) 3.31 2.90 2.75 ANNUAL RUNOFF (INCHES) 44.93 39.42 37.33 10 PERCENT EXCEEDS 253 233 205 50 PERCENT EXCEEDS 75 61 53 90 PERCENT EXCEEDS 34 25 22 e Estimated 95 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 96 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- October, 1995 to current water year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October, 1995 to current water year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1996. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediments samples were collected by hydrologic technician and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 24,800 mg/L September 22, 1998; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, e952,000 tons (e864,000 tonnes) September 22, 1998; Minimum daily mean, 0.04 ton (0.03 tonne) December 29-30, 1998. EXTREMES FOR CURRENT YEAR 2000. SEDIMENT CONCENTRATION: Maximum daily mean, 6,340 mg/L November 19, 1999; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 18,700 tons (16,965 tonnes) November 18, 1999; Minimum daily mean, 0.06 ton (0.05 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 e173 e157 e75 e236 e551 e372 161 126 58 2 154 39 16 e287 e1020 e1680 233 380 366 3 139 21 7.8 e286 e888 e908 291 647 583 4 130 16 5.6 e227 e193 e121 195 55 30 5 129 35 12 e227 e303 e242 227 355 259 6 142 137 59 e190 e91 e49 245 136 99.8 7 158 283 134 e159 e28 e12 201 60 32 8 191 359 202 e148 e23 e9.1 194 59 31 9 150 162 68 e153 e34 e14 170 40 19 10 137 42 16 e134 e43 e15 160 26 12 11 235 874 1510 e132 e29 e10 144 18 7.0 12 216 153 95 e126 e22 e7.5 135 15 5.5 13 214 177 126 e118 e29 e9.3 127 26 8.9 14 164 284 127 e112 e40 e12 120 35 11 15 169 264 137 e109 e49 e14 e115 e11 e3.5 16 215 446 288 e231 e668 e782 e110 e11 e3.1 17 294 1010 1260 725 5340 16400 e114 e9 e2.9 18 285 882 783 1230 4680 18600 104 9 2.5 19 206 290 165 971 6340 18400 107 13 3.8 20 264 616 727 585 312 531 106 20 5.7 21 266 330 229 397 120 129 106 28 8.0 22 275 53 40 312 68 57 120 78 25 23 226 31 19 276 63 47 108 93 27 24 204 27 15 250 62 42 104 61 17 25 e250 e875 e772 231 38 24 102 40 11 26 e234 e180 e119 210 23 13 97 28 7.3 27 e206 e63 e35 191 20 10 92 25 6.2 28 e251 e459 e472 183 19 9.3 93 23 5.7 29 e225 e172 e106 166 22 10 155 21 8.6 30 e245 e418 e347 164 67 33 105 16 4.6 31 e492 e3080 e13900 --- --- --- 98 12 3.3 TOTAL 6639 --- 21867.4 8766 --- 58562.2 4439 --- 1667.4 97 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 94 9 2.4 53 3 .43 38 1 .11 2 91 7 1.8 e52 e3 e.44 35 1 .12 3 116 63 24 51 4 .54 34 1 .13 4 130 183 74 50 5 .68 33 2 .15 5 118 73 23 49 7 .87 33 2 .19 6 121 111 44 49 7 .94 33 4 .34 7 115 79 26 48 5 .61 32 7 .62 8 100 31 8.4 49 3 .39 32 11 .99 9 92 19 4.9 45 2 .27 32 8 .71 10 85 14 3.1 43 3 .34 31 5 .43 11 80 10 2.1 42 4 .46 30 3 .26 12 77 7 1.5 41 6 .62 30 2 .17 13 79 7 1.5 41 8 .86 30 3 .21 14 80 7 1.5 42 8 .95 30 3 .26 15 82 33 21 41 4 .49 30 4 .33 16 156 189 101 40 2 .25 30 5 .41 17 84 72 16 40 2 .22 30 6 .52 18 e77 e53 e11 40 2 .22 30 8 .65 19 e72 e39 e7.5 41 2 .22 28 10 .73 20 e67 e28 e5.1 41 2 .22 28 8 .62 21 e64 e21 e3.6 39 2 .21 28 7 .53 22 e62 e15 e2.6 40 2 .22 30 6 .44 23 e62 e11 e1.9 208 1680 3460 28 4 .28 24 e61 e8 e1.4 88 136 46 32 2 .20 25 e62 e6 e1.1 88 17 4.0 29 2 .12 26 e68 e5 e.91 57 9 1.4 27 1 .08 27 61 4 .72 52 7 1.1 29 1 .08 28 56 4 .58 44 4 .46 28 1 .08 29 58 3 .52 40 2 .20 57 31 5.4 30 57 3 .47 --- --- --- 42 23 3.3 31 54 3 .44 --- --- --- 32 11 1.0 TOTAL 2581 --- 394.04 1554 --- 3523.61 991 --- 19.46 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 31 10 .91 24 6 .37 39 2 .18 2 32 15 1.3 24 2 .15 38 3 .27 3 32 7 .59 211 1350 3520 37 4 .41 4 28 3 .27 231 1050 1810 35 6 .56 5 27 2 .15 138 522 252 34 6 .59 6 26 2 .14 99 157 55 33 7 .60 7 25 2 .14 155 496 378 32 6 .55 8 26 2 .14 326 1830 4390 32 4 .35 9 25 2 .14 445 2520 7980 32 3 .22 10 31 6 .76 211 233 163 32 2 .13 11 42 19 2.4 182 408 327 32 1 .09 12 26 6 .40 177 389 200 41 11 1.8 13 24 6 .36 110 75 23 60 43 11 14 24 6 .39 87 18 4.4 61 63 12 15 23 7 .41 71 17 3.3 52 32 5.0 16 23 7 .42 62 18 3.0 111 223 147 17 25 5 .37 73 48 13 62 107 19 18 29 5 .43 79 76 18 40 66 7.2 19 40 9 1.1 58 22 3.5 35 62 5.9 20 58 34 7.9 54 10 1.5 61 114 31 21 69 48 14 57 6 .87 46 89 12 22 40 19 2.3 54 7 1.0 35 43 4.1 23 29 6 .47 66 30 10 32 23 2.0 24 27 8 .56 70 48 9.9 31 12 1.0 25 25 11 .78 53 19 2.8 32 7 .62 26 25 15 1.0 51 6 .89 31 5 .43 27 24 16 1.0 47 2 .30 30 4 .32 28 23 15 .98 45 5 .63 28 3 .25 29 23 15 .93 49 73 9.9 27 5 .35 30 23 13 .81 45 11 1.3 27 7 .52 31 --- --- --- 41 1 .14 --- --- --- TOTAL 905 --- 41.55 3395 --- 19182.95 1218 --- 265.44 98 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 27 11 .80 31 11 1.3 188 502 734 2 29 13 1.0 29 12 .95 173 52 34 3 28 6 .45 26 7 .52 112 18 5.3 4 26 2 .16 26 5 .38 101 41 14 5 25 1 .07 24 4 .26 165 180 124 6 26 1 .07 23 3 .18 152 39 20 7 28 1 .08 23 3 .16 113 13 3.9 8 25 1 .07 25 2 .15 92 12 2.9 9 25 1 .08 23 2 .12 81 11 2.4 10 24 3 .17 32 11 1.4 141 130 73 11 24 6 .38 28 11 .80 96 91 24 12 24 8 .55 24 9 .56 81 50 11 13 23 3 .19 23 7 .44 73 31 6.0 14 23 1 .07 28 11 1.2 71 28 5.4 15 22 1 .06 37 14 1.5 76 27 5.5 16 22 1 .06 36 7 .67 93 64 23 17 23 1 .06 29 5 .39 103 90 31 18 24 1 .06 25 4 .25 569 2050 4120 19 22 1 .06 26 3 .18 385 1480 2620 20 128 463 699 25 2 .14 338 1110 1050 21 48 36 5.8 23 2 .12 279 423 319 22 28 7 .52 177 1270 8850 343 1110 1600 23 26 4 .29 1010 1870 8630 373 1130 1580 24 30 8 .99 195 132 76 298 127 105 25 31 12 1.0 168 203 147 219 44 26 26 25 9 .61 173 337 168 219 246 200 27 24 7 .48 138 164 63 323 328 481 28 23 6 .38 109 95 28 280 602 636 29 23 5 .31 103 94 31 208 95 53 30 24 4 .27 122 116 56 193 85 44 31 23 4 .25 116 158 55 --- --- --- TOTAL 903 --- 714.34 2877 --- 18115.67 5938 --- 13953.4 YEAR 40206 138307.66 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- SEDI- SED. CHARGE, MENT, SUSP. INST. SEDI- DIS- SIEVE CUBIC MENT, CHARGE, DIAM. FEET SUS- SUS- % FINER DATE TIME PER PENDED PENDED THAN SECOND (MG/L) (T/DAY) .062 MM (00061) (80154) (80155) (70331) OCT 17... 1558 200 6460 3490 71 18... 1745 439 3150 3730 65 JAN 16... 1100 148 100 40 88 APR 16... 0900 23 7 .43 58 99 RIO GRANDE DE ARECIBO BASIN 50026050 RIO CAONILLAS ABOVE LAGO CAONILLAS NEAR JAYUYA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°13'26", long 66°38'22", 300 ft (91 m) off Highway 531, 700 ft (213 m) upstream from Lago Caonillas, 3.3 mi (5.3 km) northwest of Jayuya plaza. DRAINAGE AREA.--40.4 mi2 (104.6 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, NESS CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR TOTAL FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. (MG/L DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER AS SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) NOV 09... 1430 164 192 7.9 25.0 25 7.9 99 14 K1800 510 68 MAR 06... 1200 40 268 8.3 23.7 .9 8.2 100 <10 K6 K5 -- MAY 11... 1215 159 163 7.3 24.6 3.6 7.9 98 <10 580 380 62 SEP 08... 1400 92 188 7.6 28.6 2.0 7.5 100 <10 K990 K130 68 ANC SOLIDS, MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- DATE (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) NOV 09... 17.9 5.63 9.1 .5 1.4 62 <1.0 11.5 9.1 <.1 28.2 120 MAR 06... -- -- -- -- -- 84 -- -- -- -- -- -- MAY 11... 16.1 5.22 8.8 .5 1.6 49 <1.0 11.8 10.1 <.1 24.3 107 SEP 08... 18.2 5.42 10.2 .5 1.5 65 -- 11.2 8.8 <.1 23.1 117 RESIDUE NITRO- SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM DIS- AT 105 GEN, GEN, GEN, GEN, MONIA + PHOS- TOTAL TOTAL WATER SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC PHORUS ARSENIC RECOV- RECOV- UNFLTRD (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS P) AS AS) AS BA) AS B) AS CD) (70302) (00530) (00620) (00615) (00630) (00610) (00625) (00665) (01002) (01007) (01022) (01027) NOV 09... 53.2 42 -- <.01 1.0 .02 <.20 .070 <3 34.4 E18 <.1 MAR 06... -- 2 .75 .01 .8 .03 <.20 .020 -- -- -- -- MAY 11... 46.2 <10 -- <.01 1.1 .02 <.20 .040 <3 23.8 27 <.1 SEP 08... 29.2 <10 -- <.01 .5 .01 <.20 .030 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 09... E1 E12 1820 E1 82 <.3 <3 <1 <31 <.01 <4 <.02 MAR 06... -- -- -- -- -- -- -- -- -- -- -- -- MAY 11... <1 <20 480 <1 28 <.3 <3 <1 <31 <.01 7 <.02 SEP 08... -- -- -- -- -- -- -- -- -- -- -- -- 100 RIO GRANDE DE ARECIBO BASIN 50026140 LAGO CAONILLAS AT DAMSITE NEAR UTUADO, PR LOCATION.--Lat 18°16'43",long 66°39'24", Hydrologic Unit 21010001, at Lago Caonillas Dam on Río Caonillas, 2.9 mi (4.7 km) northeast of Plaza de Utuado, 0.3 mi (0.6 km) west from Iglesia Santa María del Monte Carmelo, and 1.8 mi (3.0 km) northwest from Hacienda Carbonell. DRAINAGE AREA.--48.4 mi2 (125.4 km2). ELEVATION RECORDS PERIOD OF RECORD.--March 1991 to current year. (March 16 to September 30, 1999, no records available due to repairs conducted by Puerto Rico Electric and Power Authority; inspections data available at District Office). Prior to October 1994, published as Lago Caonillas at Caonillas. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Caonillas was completed in 1948. The dam is a concrete gravity structure with a total length of 815 ft (248 m), a maximum height of 235 ft (72 m), and a maximum base width of 195 ft (59 m). Non-overflow sections on each abutment have a total length of 603 ft (184 m). The dam is the main unit of Caonillas Hydroelectric Project, and provides 49,000 acre-feet (60 hm3) of usable storage for power generation at Caonillas Power Plant No. 1 located 2.5 mi (4.0 km) downstream from the dam. The dam is owned by Puerto Rico Electric Power Authority. Gage-height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 96-4153,Februay 1995. Record is poor, periods of no gage-heiht record due to repairs by PREPA to diversion tunnel. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 841.29 ft (256.42 m), Sept. 22, 1998; minimun elevation, 737.92 ft (224.92 m), Aug. 8, 1997. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 829.68 ft (252.89 m), May 12; minimum elevation, 820.33 ft (250.04 m), July 20, 2000. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 96-4153,Puerto Rico-1995) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 689 0 745 6,015 705 778 764 10,077 725 2,919 830 42,295 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 A A A A A A 825.37 822.38 825.53 A A 825.86 2 A A A A A A 825.15 822.31 824.71 A A 823.25 3 A A A A A A 824.99 823.74 824.46 A A 823.66 4 A A A A A A 824.77 824.68 824.20 A A 823.69 5 A A A A A A 824.51 824.94 824.05 A A 824.13 6 A A A A A A 824.28 825.05 823.84 A A 824.39 7 A A A A A A 824.06 825.48 823.64 A A 824.33 8 A A A A A A 823.61 827.36 A A A 824.41 9 A A A A A A 823.53 829.57 A A A 824.28 10 A A A A A A 823.60 829.27 A A A 824.20 11 A A A A A A 823.73 829.55 A A A 824.05 12 A A A A A A 823.79 829.42 A A A 824.19 13 A A A A A 826.10 823.81 829.31 A A A 824.21 14 A A A A A 824.85 823.84 829.26 A A A 824.20 15 A A A A A 824.71 823.86 829.11 A 822.63 A 823.99 16 A A A A A 824.56 823.88 828.93 A 822.16 A 823.72 17 A A A A A 824.12 823.75 828.94 A 821.97 A 823.55 18 A A A A A A 823.80 828.85 A 821.46 A 825.48 19 A A A A A A 823.42 828.63 A 821.10 A 826.32 20 A A A A A A 823.45 828.40 A 822.41 A 826.38 21 A A A A A A 823.56 828.16 A 822.29 A 825.67 22 A A A A A 825.64 823.40 827.92 A 822.17 A 825.75 23 A A A A A 825.56 823.34 827.74 A 821.91 A 825.77 24 A A A A A 825.57 823.15 827.62 A 821.66 A 825.52 25 A A A A A 825.50 823.01 827.35 A 821.45 A 825.24 26 A A A A A 825.45 822.85 827.09 A A A 824.99 27 A A A A A 825.38 822.66 826.76 A A A 825.15 28 A A A A A 825.42 822.50 826.48 A A A 825.15 29 A A A A A 825.63 822.40 826.20 A A A 824.82 30 A A A A --- 825.73 822.42 826.13 A A A 824.41 31 A --- A A --- 825.55 --- 825.81 --- A 825.83 --- MAX --- --- --- --- --- 826.10 825.37 829.57 825.53 822.63 825.83 826.38 MIN --- --- --- --- --- 824.12 822.40 822.31 823.64 821.10 825.83 823.25 A No gage-height record 101 RIO GRANDE DE ARECIBO BASIN 50026140 LAGO CAONILLAS AT DAMSITE NEAR UTUADO, PR--Continued O N D 1999 J F M A M J J A S 2000 820 822 824 826 828 830 ELEVATION, IN FEET Gap indicates missing record 102 RIO GRANDE DE ARECIBO BASIN 50026400 RIO YUNES AT HWY 140 NEAR FLORIDA, PR LOCATION.--Lat 18°19'27', long 66°35'13", Hydrologic Unit 21010002, on left bank, 600 ft downstream from bridge on Hwy 140, 3.07 mi (4.9 km) southwest from Florida Plaza, 2.41 mi (3.94 km) northwest from Escuela Segunda Unidad de Frontón, 1.9 mi (3.1 km) northeast from Escuela Segunda Unidad de Mameyes. DRAINAGE AREA.--13.9 mi2 (36.1 km2). PERIOD OF RECORD.--June to September 2000. GAGE.--Water-stage recorder. Elevation of gage is 492 ft (150 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 6.9 5.8 27 2 7.1 6.9 38 3 7.1 6.2 13 4 6.7 9.0 94 5 6.5 7.5 42 6 6.3 5.7 27 7 6.3 5.5 15 8 7.9 5.3 12 9 6.4 5.0 14 10 6.5 8.8 27 11 6.2 6.1 19 12 6.4 4.7 11 13 6.3 4.9 10 14 6.1 5.0 9.7 15 5.5 6.0 11 16 5.4 5.5 9.6 17 7.6 5.2 15 18 8.1 4.8 63 19 6.7 5.2 35 20 51 5.3 27 21 16 5.0 47 22 e8.6 8.3 8.2 47 23 8.1 7.1 95 34 24 7.7 6.7 17 23 25 7.7 6.5 13 19 26 8.3 6.5 32 17 27 8.1 6.0 16 19 28 7.5 5.6 9.6 18 29 7.1 7.2 8.1 16 30 6.9 7.2 8.2 14 31 5.9 10 --- TOTAL 70.0 260.0 340.5 773.3 MEAN 7.78 8.39 11.0 25.8 MAX 8.6 51 95 94 MIN 6.9 5.4 4.7 9.6 AC-FT 139 516 675 1530 CFSM .56 .60 .79 1.84 IN. .19 .69 .91 2.06 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2000, BY WATER YEAR (WY) MEAN --- --- --- --- --- --- --- --- --- 8.39 11.0 25.8 MAX --- --- --- --- --- --- --- --- --- 8.39 11.0 25.8 (WY) --- --- --- --- --- --- --- --- --- 2000 2000 2000 MIN --- --- --- --- --- --- --- --- --- 8.39 11.0 25.8 (WY) --- --- --- --- --- --- --- --- --- 2000 2000 2000 SUMMARY STATISTICS FOR 2000 WATER YEAR HIGHEST DAILY MEAN 95 Aug 23 LOWEST DAILY MEAN 4.7 Aug 12 ANNUAL SEVEN-DAY MINIMUM 5.2 Aug 12 INSTANTANEOUS PEAK FLOW 995 Sep 4 INSTANTANEOUS PEAK STAGE 7.81 Sep 4 INSTANTANEOUS LOW FLOW 4.4 Aug 12 10 PERCENT EXCEEDS 34 50 PERCENT EXCEEDS 7.9 90 PERCENT EXCEEDS 5.3 e Estimated 103 RIO GRANDE DE ARECIBO BASIN 50026400 RIO YUNES AT HWY 140 NEAR FLORIDA, PR--Continued O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND Gap indicates missing record 104 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR LOCATION.--Lat 18°19'32', long 66°37'24", Hydrologic Unit 21010002, on right bank off Hwy. 146 2.16 mi(3.47 km) northwest from Escuela Segunda Unidad de Mameyes, 3.0 mi (4.82 km) southwest from Lago Dos Bocas Dam, 3.75 mi (6.03 km) northeast from Lago Caonillas Dam. WATER-DISCHARGE RECORDS DRAINAGE AREA.--33.2 mi2 (86.0 km2). PERIOD OF RECORD.--December 16, 1999 to September 30, 2000. GAGE.--Water-stage recorder. Datum of gage is 311.6 ft (94.97 m),from topographic map. REMARKS.--Records fair, except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 114 68 52 39 32 42 28 23 44 2 113 66 51 38 43 42 29 26 72 3 225 66 50 42 298 41 28 24 37 4 180 65 49 38 201 40 26 e29 94 5 145 63 49 37 144 38 26 e28 111 6 149 61 48 35 64 38 25 22 71 7 145 61 47 35 51 37 77 21 47 8 130 60 47 34 205 38 40 20 45 9 119 58 46 33 261 41 28 19 69 10 111 57 45 32 143 38 26 35 72 11 107 56 44 33 e262 35 26 23 57 12 103 55 44 34 e131 e38 25 19 41 110 54 44 32 e93 e58 25 19 36 14 106 54 43 31 e76 44 25 19 34 15 109 52 42 30 e67 36 23 22 35 16 144 51 42 30 e62 40 22 21 33 17 150 104 51 45 31 e88 41 e23 19 42 18 139 97 52 41 31 e79 34 e29 18 115 19 139 93 52 40 30 e63 33 24 19 74 20 140 90 50 39 74 e57 38 109 19 56 21 142 88 49 40 70 e53 42 49 18 64 22 164 85 61 44 59 e52 33 29 24 67 23 138 83 106 38 36 88 31 26 170 61 24 135 80 78 44 33 66 30 e25 48 48 25 134 78 83 39 31 60 30 e24 40 68 26 129 77 61 48 30 52 35 24 78 50 27 117 75 65 52 29 48 32 23 43 49 28 133 73 55 38 28 48 29 22 32 48 29 171 78 53 48 29 46 29 25 28 41 30 131 73 65 29 46 28 26 27 37 31 121 69 --- 52 --- 43 --- 23 30 --- TOTAL 2083 3353 1763 1416 1093 3022 1111 960 983 1718 MEAN 139 108 60.8 45.7 36.4 97.5 37.0 31.0 31.7 57.3 MAX 171 225 106 65 74 298 58 109 170 115 MIN 117 69 49 38 28 32 28 22 18 33 AC-FT 4130 6650 3500 2810 2170 5990 2200 1900 1950 3410 CFSM 4.18 3.26 1.83 1.38 1.10 2.94 1.12 .93 .96 1.72 IN. 2.33 3.76 1.98 1.59 1.22 3.39 1.24 1.08 1.10 1.92 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2000, BY WATER YEAR (WY) MEAN --- --- --- 108 60.8 45.7 36.4 97.5 37.0 31.0 31.7 57.3 MAX --- --- --- 108 60.8 45.7 36.4 97.5 37.0 31.0 31.7 57.3 (WY) --- --- --- 2000 2000 2000 2000 2000 2000 2000 2000 2000 MIN --- --- --- 108 60.8 45.7 36.4 97.5 37.0 31.0 31.7 57.3 (WY) --- --- --- 2000 2000 2000 2000 2000 2000 2000 2000 2000 SUMMARY STATISTICS FOR 2000 WATER YEAR HIGHEST DAILY MEAN 298 May 3 LOWEST DAILY MEAN 18 Aug 18 ANNUAL SEVEN-DAY MINIMUM 19 Aug 15 INSTANTANEOUS PEAK FLOW 2330 May 3 INSTANTANEOUS PEAK STAGE 10.33 May 3 INSTANTANEOUS LOW FLOW 17 Aug 18 10 PERCENT EXCEEDS 129 50 PERCENT EXCEEDS 46 90 PERCENT EXCEEDS 25 e Estimated 105 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND Gap indicates missing record 106 RIO GRANDE DE ARECIBO BASIN 50027100 LAGO DOS BOCAS AT DAMSITE NEAR UTUADO, PR LOCATION.--Lat 18°20'16",long 66°40'05", Hydrologic Unit 21010001, on upstream side of road 146 over damsite, close to the center of dam near bridge center, 10 mi (16.09 km) southeast of the city of Arecibo, 4.10 mi (6.596 km) north of Lago Caonillas Dam, 5.30 mi (8.527 km) northeast of Utuado Plaza, and 3.80 mi (6.114 km) southeast of Escuela Antonio Sánchez de Padilla. DRAINAGE AREA.--169.45 mi2 (438.87 km2). ELEVATION RECORDS PERIOD OF RECORD.--March 1999 to current year. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Dos Bocas was completed in 1942. The dam is a concrete gravity structure with a total length of 1,317 ft (401.42 m), a maximum height of 188 ft (57.302 m), and a maximum base width of 158 ft (48.158 m). No-overflow sections on each abutment have a total lenght of 957 ft (292 m). The dam and the powerplant comprise the Dos Bocas Hydroelectric Project, and provides 32,000 acre-feet (39.456 km3). A three-unit powerplant is located on the right bank of the slitting basin. The dam is owned by Puerto Rico Electric Power Authority. The capacity of Lago Dos Bocas was computed to be 714.40 million ft3 (20.23 million me3) for June 1997. The Puerto Rico Aqueduct and Sewer Authority (PRASA) plans to withdraw water from the Rio Grande de Arecibo, south of the town of Arecibo, to supply potable water for areas between Arecibo and San Juan town. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 298.55 ft (90.998 m), Nov.19,1999; minimum elevation, 283.88 ft (86.526 m), Aug.21,2000. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 216 0 275 9,283 236 1,403 288 13,684 256 4,491 295 16,400 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 290.77 A 292.83 292.71 292.33 292.47 291.29 A A 288.83 290.77 291.26 2 291.17 A 296.71 292.20 292.77 292.28 290.14 A A 289.40 290.28 291.24 3 291.39 A 294.96 292.45 293.65 292.46 289.44 A A 289.88 289.80 291.79 4 291.03 A 292.88 291.85 293.36 291.05 289.88 A A 290.30 288.68 292.23 5 291.27 A 294.70 292.13 293.44 290.26 289.63 A A 290.30 286.43 A 6 290.63 A 294.45 292.36 293.38 290.30 290.41 A 291.81 290.71 286.76 A 7 290.92 A 293.37 292.11 293.51 290.20 291.26 A 292.10 291.95 286.75 A 8 291.24 A 292.89 291.86 293.50 290.00 288.79 A 292.34 292.21 286.40 292.76 9 291.53 294.38 292.42 292.06 292.33 289.78 288.60 A 292.11 292.07 286.27 A 10 291.77 293.42 291.43 291.41 290.86 289.44 288.55 A 291.78 291.83 286.73 290.98 11 292.52 292.83 292.23 291.01 290.10 288.92 289.16 A A 289.88 287.09 289.68 12 292.07 A 292.99 290.37 289.86 289.40 289.62 A A 290.05 287.18 290.54 13 292.13 292.18 292.63 289.60 289.59 289.99 290.00 A 293.04 290.18 287.28 290.27 14 291.55 292.77 292.86 288.01 289.44 290.64 290.47 A 295.06 290.60 287.46 290.26 15 A 289.24 292.92 288.39 290.17 291.39 290.86 A 293.73 290.94 286.77 289.73 16 292.20 286.77 292.70 289.79 290.95 291.32 291.23 A 293.85 290.59 286.10 287.73 17 293.48 294.07 293.11 289.97 290.77 292.49 290.17 A 291.25 291.32 285.31 286.61 18 292.86 298.48 293.05 290.34 290.64 292.96 290.61 A 291.01 292.45 285.56 292.58 19 291.60 297.71 292.74 290.73 290.50 293.29 291.30 A 290.23 293.06 285.86 293.35 20 290.12 A 291.97 289.83 290.19 293.19 292.15 A 290.71 293.52 286.07 293.81 21 290.18 296.05 291.99 289.42 289.75 293.07 293.16 A 291.15 293.09 283.91 294.49 22 290.84 295.15 292.06 289.72 290.57 293.45 293.53 A 290.19 293.59 284.49 294.52 23 291.25 294.38 292.23 290.03 292.37 294.17 293.47 A 290.44 292.57 A 294.61 24 291.60 294.08 292.01 A 293.64 294.76 293.52 A 290.26 293.10 A 292.98 25 292.46 293.77 291.78 A 293.50 292.37 A A 290.09 293.12 291.83 292.21 26 292.84 292.86 291.71 290.71 293.07 292.27 293.14 A 290.18 292.92 293.27 291.50 27 292.30 292.38 291.25 291.03 293.23 292.61 A A 290.72 292.33 292.05 291.52 28 292.11 290.90 292.24 291.30 292.94 293.04 292.57 A 290.04 292.56 291.07 290.06 29 292.38 290.69 292.47 A 292.44 293.33 A A 289.90 292.31 291.21 287.18 30 293.54 292.06 291.71 291.80 --- 292.96 A A 289.11 291.68 291.56 288.51 31 A --- 292.13 292.02 --- 292.12 --- A --- 291.15 291.44 --- MAX 293.54 298.48 296.71 292.71 293.65 294.76 293.53 --- 295.06 293.59 293.27 294.61 MIN 290.12 286.77 291.25 288.01 289.44 288.92 288.55 --- 289.11 288.83 283.91 286.61 A No gage-height record 107 RIO GRANDE DE ARECIBO BASIN 50027100 LAGO DOS BOCAS AT DAMSITE NEAR UTUADO, PR--Continued O N D 1999 J F M A M J J A S 2000 282 284 286 288 290 292 294 296 298 300 ELEVATION, IN FEET Gap indicates missing record 108 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°20'50", long 66°40'02", at pedestrian bridge, 0.7 mi (1.1 km) downstream from Lago Dos Bocas and 6.6 mi (10.6km) west of Florida plaza. DRAINAGE AREA.--169 mi2 (436 km2) does not include 6.0 mi2 (15.6 km2) above Lago Garzas. PERIOD OF RECORD.--Water years 1970-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) NOV 04... 1220 E1500 179 7.7 25.3 160 6.6 80 <10 K640 K640 FEB 29... 0915 43 234 7.6 23.0 2.0 7.0 82 <10 K27 K140 MAR 29... 1000 55 235 7.7 25.5 .7 7.5 91 <10 K4 K17 MAY 02... 1600 63 218 7.1 25.4 .5 4.4 55 <10 K70 250 SEP 07... 1500 E1000 204 7.1 26.7 15 3.6 45 <10 320 800 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) NOV 04... 65 18.0 4.94 7.9 .4 2.3 57 <1.0 11.7 7.8 FEB 29... -- -- -- -- -- -- 82 -- -- -- MAR 29... 86 22.9 6.89 11.2 .5 1.8 -- <1.0 13.5 11.7 MAY 02... 84 22.7 6.59 10.8 .5 1.9 78 <1.0 13.7 11.3 SEP 07... 74 19.9 5.84 10.2 .5 2.0 72 -- 11.1 9.6 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 04... .1 20.2 107 -- 132 .90 .02 .9 .05 .38 FEB 29... -- -- -- -- 1 .60 .01 .6 .08 -- MAR 29... <.1 16.9 -- -- 1 .28 .02 .3 .10 .22 MAY 02... <.1 20.0 134 22.6 <1 -- <.01 .1 .14 .10 SEP 07... <.1 18.7 121 -- 11 -- <.01 .3 .16 .16 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) NOV 04... .43 1.4 6.0 .130 <3 69.9 E15 .2 3 E20 FEB 29... <.20 -- -- <.020 -- -- -- -- -- -- MAR 29... .32 .62 2.7 <.020 <3 34.3 E12 E.1 <1 <20 MAY 02... .24 .38 1.7 <.020 E2 34.3 E14 <.1 <1 <20 SEP 07... .32 .65 2.9 .030 -- -- -- -- -- -- 109 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 04... 4430 3 225 <.3 <3 <1 E18 <.01 9 .04 FEB 29... -- -- -- -- -- -- -- -- -- -- MAR 29... 40 <1 110 <.3 <3 <1 <31 <.01 <4 <.02 MAY 02... 120 <1 160 <.3 <3 <1 <31 <.01 <4 <.02 SEP 07... -- -- -- -- -- -- -- -- -- -- 110 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR LOCATION.--Lat 18°25'22', long 66°41'58", Hydrologic Unit 21010002, 0.5 mi (0.8 km) upstream from Río Tanamá, 3.6 mi (5.8 km), south of Arecibo and 4.9 mi (7.9 km) above mouth, and 10.4 mi (16.7 km) downstream from Lago Dos Bocas. DRAINAGE AREA.--174 mi2 (451 km2), approximately, of which an undetermined amount does not contribute directly to surface runoff. PERIOD OF RECORD.--April 1982 to current year. GAGE.--Water-stage recorder. Elevation of gage is 30 ft (9 m), from topographic map. REMARKS.--Records poor. Flow regulated by Lago Dos Bocas Dam 10.4 mi (16.7 km) upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 433 1350 389 282 182 188 359 188 377 124 146 414 2 307 745 818 398 170 175 369 191 295 126 125 361 3 235 902 1380 459 144 196 358 223 267 44 148 400 4 416 812 1000 531 102 291 222 639 300 25 198 411 5 263 626 796 451 217 249 196 577 200 68 359 165 6 434 593 886 389 191 236 253 362 78 68 193 367 7 469 520 864 423 196 173 108 388 190 45 66 222 8 451 373 739 391 178 188 376 616 196 73 62 242 9 314 395 656 338 282 194 256 993 209 104 100 190 10 243 481 677 385 365 202 254 962 206 131 93 365 11 417 503 506 393 303 261 198 849 198 302 38 350 12 537 375 391 355 205 150 101 1050 191 146 23 187 13 512 431 565 403 209 84 90 690 95 71 56 31 14 649 263 402 463 208 65 90 382 198 84 56 132 15 630 829 398 323 193 62 81 350 361 45 118 211 16 579 868 454 332 78 64 71 340 155 61 97 422 17 592 727 410 413 54 177 161 458 624 176 140 406 18 1080 1450 406 267 183 65 218 584 275 29 150 310 19 901 2340 438 143 198 62 149 551 344 37 51 366 20 891 1780 550 351 211 64 113 570 155 169 45 529 21 694 1200 430 326 231 179 162 296 217 110 122 588 22 709 976 438 237 214 93 254 108 265 220 162 911 23 429 946 409 203 83 68 225 118 236 126 730 793 24 409 779 409 203 121 72 197 250 124 244 914 802 25 650 723 422 207 249 251 208 292 183 73 700 617 26 644 706 379 206 310 291 226 228 208 136 325 530 27 597 658 390 204 243 208 207 309 144 118 577 522 28 511 699 329 194 200 152 256 345 102 164 450 600 29 375 631 330 193 279 110 220 380 193 52 362 827 30 324 451 502 209 --- 228 195 407 158 119 260 279 31 1140 --- 327 187 --- 360 --- 302 --- 155 267 --- TOTAL 16835 24132 17090 9859 5799 5158 6173 13998 6744 3445 7133 12550 MEAN 543 804 551 318 200 166 206 452 225 111 230 418 MAX 1140 2340 1380 531 365 360 376 1050 624 302 914 911 MIN 235 263 327 143 54 62 71 108 78 25 23 31 AC-FT 33390 47870 33900 19560 11500 10230 12240 27770 13380 6830 14150 24890 CFSM 3.12 4.62 3.17 1.83 1.15 .96 1.18 2.60 1.29 .64 1.32 2.40 IN. 3.60 5.16 3.65 2.11 1.24 1.10 1.32 2.99 1.44 .74 1.52 2.68 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1982 - 2000, BY WATER YEAR (WY) MEAN 582 513 297 244 220 209 319 526 342 237 262 523 MAX 1984 1413 570 437 428 351 617 2000 683 374 474 1479 (WY) 1986 1986 1988 1988 1988 1985 1986 1986 1987 1987 1988 1996 MIN 171 123 72.4 83.5 61.2 60.1 65.7 178 69.3 62.7 82.8 99.9 (WY) 1995 1995 1995 1995 1995 1998 1995 1994 1994 1994 1994 1994 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1982 - 2000 ANNUAL TOTAL 148641 128916 ANNUAL MEAN 407 352 356 HIGHEST ANNUAL MEAN 729 1986 LOWEST ANNUAL MEAN 132 1994 HIGHEST DAILY MEAN 2340 Nov 19 2340 Nov 19 14800 May 18 1985 LOWEST DAILY MEAN 45 Feb 23 23 Aug 12 16 Apr 14 1994 ANNUAL SEVEN-DAY MINIMUM 69 Feb 18 61 Jul 3 22 Mar 30 1994 INSTANTANEOUS PEAK FLOW 2870 Oct 31 45800 May 18 1985 INSTANTANEOUS PEAK STAGE 8.63 Oct 31 18.22 May 18 1985 ANNUAL RUNOFF (AC-FT) 294800 255700 257600 ANNUAL RUNOFF (CFSM) 2.34 2.02 2.04 ANNUAL RUNOFF (INCHES) 31.78 27.56 27.76 10 PERCENT EXCEEDS 781 713 731 50 PERCENT EXCEEDS 355 267 239 90 PERCENT EXCEEDS 113 84 56 111 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 112 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water year 1982 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October, 1995 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1995. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediments samples were collected by hydrologic technician and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 3,510 mg/L September 22, 1998; Minimum daily mean, 1 mg/L several days during Water Year 2000. SEDIMENT LOADS: Maximum daily mean, e84,900 tons (77,000 tonnes) September 22,1998; Minimum daily mean, 0.06 ton (0.05 tonne) August 12, 2000. EXTREMES FOR CURRENT YEAR 2000. SEDIMENT CONCENTRATION: Maximum daily mean, 531 mg/L November 1, 1999; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 2,020 tons (1,832 tonnes) November 1, 1999; Minimum daily mean, 0.06 ton (0.05 tonne) August 12, 2000. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 433 52 74 1350 531 2020 389 31 36 2 307 32 34 745 292 579 818 79 253 3 235 32 24 902 199 483 1380 181 689 4 416 40 50 812 144 314 1000 116 315 5 263 22 22 626 104 174 796 74 158 6 434 22 34 593 44 80 886 47 113 7 469 27 44 520 49 72 864 33 77 8 451 30 40 373 32 38 739 39 78 9 314 26 26 395 26 32 656 50 89 10 243 24 20 481 47 65 677 54 98 11 417 38 47 503 48 68 506 50 67 12 537 70 133 375 54 54 391 26 30 13 512 61 107 431 42 55 565 37 58 14 649 63 119 263 34 28 402 14 17 15 630 53 102 829 58 131 398 32 42 16 579 48 88 868 27 63 454 38 55 17 592 57 132 727 22 44 410 34 44 18 1080 270 794 1450 47 223 406 33 43 19 901 218 531 2340 285 1800 438 34 48 20 891 141 338 1780 317 1510 550 52 79 21 694 82 158 1200 340 1090 430 31 44 22 709 69 144 976 365 961 438 31 42 23 429 40 50 946 310 790 409 31 41 24 409 30 39 779 72 157 409 54 59 25 650 146 323 723 46 97 422 30 41 26 644 80 154 706 54 111 379 49 51 27 597 71 126 658 51 95 390 30 37 28 511 28 41 699 51 104 329 14 18 29 375 22 23 631 41 75 330 17 20 30 324 31 32 451 34 39 502 35 61 31 1140 317 1540 --- --- --- 327 21 27 TOTAL 16835 --- 5389 24132 --- 11352 17090 --- 2830 113 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 282 20 22 182 17 11 188 17 13 2 398 27 35 170 17 9.1 175 7 4.6 3 459 32 49 144 15 6.5 196 14 10 4 531 45 79 102 14 4.7 291 22 21 5 451 36 52 217 21 16 249 50 33 6 389 32 38 191 19 12 236 26 23 7 423 35 46 196 19 13 173 10 5.9 8 391 32 40 178 12 7.9 188 11 7.4 9 338 29 31 282 17 16 194 8 6.2 10 385 28 32 365 24 29 202 13 8.6 11 393 35 42 303 25 25 261 15 12 12 355 31 34 205 20 15 150 10 5.2 13 403 36 44 209 23 16 84 4 .91 14 463 44 62 208 24 17 65 4 .70 15 323 31 35 193 30 17 62 4 .67 16 332 30 34 78 17 3.8 64 4 .73 17 413 44 53 54 15 2.3 177 24 12 18 267 20 16 183 12 8.4 65 14 2.5 19 143 12 5.2 198 16 11 62 12 2.1 20 351 30 32 211 17 12 64 11 2.0 21 326 28 30 231 20 16 179 10 5.0 22 237 15 15 214 23 17 93 10 2.5 23 203 18 13 83 9 2.0 68 10 1.7 24 203 16 11 121 11 3.5 72 9 1.8 25 207 14 11 249 23 17 251 16 20 26 206 16 12 310 20 22 291 14 14 27 204 11 9.4 243 22 20 208 18 12 28 194 14 10 200 17 11 152 5 2.2 29 193 12 8.3 279 29 24 110 4 1.2 30 209 18 13 --- --- --- 228 4 2.5 31 187 17 11 --- --- --- 360 15 17 TOTAL 9859 --- 924.9 5799 --- 385.2 5158 --- 251.41 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 359 25 29 188 17 10 377 33 39 2 369 31 36 191 16 9.8 295 25 22 3 358 32 35 223 21 15 267 21 18 4 222 22 15 639 78 151 300 24 23 5 196 16 9.6 577 93 178 200 16 13 6 253 26 21 362 38 49 78 6 1.2 7 108 8 2.5 388 31 38 190 16 9.7 8 376 13 20 616 58 110 196 17 11 9 256 11 8.0 993 107 290 209 19 13 10 254 22 17 962 106 278 206 19 12 11 198 19 12 849 92 254 198 17 11 12 101 7 2.1 1050 119 343 191 17 11 13 90 7 1.6 690 65 124 95 7 1.9 14 90 6 1.4 382 37 45 198 15 11 15 81 5 1.1 350 29 33 361 26 40 16 71 5 .88 340 27 31 155 16 8.2 17 161 11 7.5 458 31 51 624 52 98 18 218 19 15 584 44 81 275 29 30 19 149 10 5.1 551 44 77 344 28 32 20 113 10 3.2 570 45 80 155 18 9.2 21 162 12 5.9 296 25 29 217 21 15 22 254 25 22 108 8 2.4 265 20 16 23 225 21 16 118 10 3.7 236 10 6.8 24 197 17 11 250 23 20 124 6 2.1 25 208 18 11 292 29 27 183 15 8.9 26 226 21 16 228 20 15 208 17 10 27 207 18 12 309 26 24 144 11 4.9 28 256 20 15 345 30 31 102 7 2.3 29 220 21 16 380 33 38 193 18 11 30 195 17 11 407 33 44 158 11 5.1 31 --- --- --- 302 26 30 --- --- --- TOTAL 6173 --- 378.88 13998 --- 2511.9 6744 --- 496.3 114 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 124 9 4.3 146 11 6.1 414 35 48 2 126 8 3.5 125 11 4.9 361 30 43 3 44 3 .36 148 14 7.4 400 33 47 4 25 2 .13 198 16 10 411 25 31 5 68 4 1.0 359 17 18 165 14 8.0 6 68 5 .97 193 5 2.9 367 24 28 7 45 3 .37 66 4 .80 222 24 30 8 73 5 1.1 62 5 .87 242 14 12 9 104 7 2.5 100 8 2.5 190 12 10 10 131 8 3.9 93 3 .77 365 29 37 11 302 15 18 38 2 .18 350 27 35 12 146 7 2.9 23 1 .06 187 8 8.0 13 71 5 1.1 56 1 .15 31 3 .30 14 84 6 1.5 56 1 .15 132 12 6.1 15 45 2 .34 118 6 3.9 211 14 11 16 61 3 .61 97 4 1.2 422 31 55 17 176 13 11 140 9 4.6 406 26 39 18 29 1 .11 150 13 6.8 310 26 31 19 37 2 .22 51 9 1.3 366 23 30 20 169 11 9.6 45 7 .91 529 36 64 21 110 7 2.6 122 11 7.3 588 59 103 22 220 9 6.7 162 14 10 911 80 197 23 126 7 3.9 730 167 419 793 78 166 24 244 8 7.4 914 134 338 802 75 163 25 73 4 .80 700 69 141 617 55 96 26 136 3 1.0 325 21 28 530 29 51 27 118 8 3.0 577 57 97 522 37 62 28 164 12 7.5 450 59 81 600 54 95 29 52 4 .63 362 31 38 827 80 179 30 119 9 3.3 260 20 18 279 23 24 31 155 11 6.7 267 18 18 --- --- --- TOTAL 3445 --- 107.04 7133 --- 1268.79 12550 --- 1709.40 YEAR 128916 27604.82 WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- SEDI- SED. CHARGE, MENT, SUSP. INST. SEDI- DIS- SIEVE CUBIC MENT, CHARGE, DIAM. FEET SUS- SUS- % FINER DATE TIME PER PENDED PENDED THAN SECOND (MG/L) (T/DAY) .062 MM (00061) (80154) (80155) (70331) NOV 02... 1708 834 294 662 95 JAN 01... 1745 92 6 1.5 95 MAY 04... 1427 735 131 260 93 05... 1727 740 166 332 94 JUL 11... 1737 620 37 62 80 AUG 23... 1142 703 756 1430 99 SEP 08... 0207 57 675 104 67 115 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR LOCATION.--Lat 18°18'02", long 66°46'58", Hydrologic Unit 21010001, on downstream side of left abutment of bridge on Highway 111, 1.2 mi (1.9 km) upstream from natural tunnel, 1.5 mi (2.4 km) northeast of Angeles, and 5.8 mi (9.3 km) northwest of Utuado. DRAINAGE AREA.--18.4 mi2 (47.7 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--June 1944 to June 1958 (daily stage and two to four measurements per month by Puerto Rico Water Resources Authority), November 1959 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 938.32 ft (286.00 m) above mean sea level. Datum of gage was increased by 3.00 ft (0.91 m) on Oct. 1978. REMARKS.--Records fair except those for estimated daily discharges, which are poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 56 91 e75 53 33 e24 e26 24 34 30 e24 149 2 54 156 e140 54 35 e24 e25 26 33 32 e28 122 3 50 125 e160 67 34 e24 e24 102 32 29 e24 81 4 48 122 e112 60 33 e24 e24 105 31 36 e26 148 5 51 106 e130 62 32 e24 e25 60 30 30 e25 147 6 64 85 e140 59 31 e24 e23 49 30 50 e23 108 7 62 81 e120 55 31 e24 e22 111 29 46 e23 94 8 54 100 e112 53 31 e24 e26 162 28 30 e23 102 9 47 98 e92 54 30 e23 e23 146 27 112 e22 98 10 44 e90 e86 48 29 e24 e27 62 26 48 e22 83 11 106 e78 78 47 29 e23 e26 275 36 39 e21 66 12 58 e68 74 45 29 e23 e24 146 42 e35 23 62 13 77 e66 73 48 29 e23 e22 78 51 e30 22 60 14 51 e74 70 46 28 e24 e21 64 63 e29 21 58 15 49 e110 68 56 27 e24 e21 54 50 e27 22 56 16 168 e113 66 86 26 e24 e21 79 115 e26 26 178 17 122 e150 68 48 26 e24 e22 116 51 e26 26 112 18 121 e210 64 44 26 e24 e22 71 35 e25 22 161 19 83 e360 63 43 26 e24 e23 52 31 e39 22 138 20 100 e280 62 41 26 e24 e21 45 86 e28 22 133 21 100 e200 62 40 25 e23 e54 47 83 e39 21 102 22 122 e145 66 38 e26 e25 e54 45 41 e27 33 235 23 128 e130 59 38 e28 e24 e29 81 35 e26 424 167 24 95 e108 58 37 e36 e25 e24 54 32 e25 145 146 25 242 e94 61 37 e27 e24 22 47 31 e40 176 120 26 145 e88 56 37 e26 e23 22 41 75 e30 160 107 27 103 e84 54 38 e26 e24 21 40 42 e26 171 151 28 149 e76 56 37 e25 e23 20 62 33 e30 130 103 29 93 e76 81 37 e24 e23 20 41 32 e25 172 92 30 90 e74 56 35 --- e23 20 38 31 e25 131 85 31 147 --- 55 33 --- e32 --- 36 --- e25 103 --- TOTAL 2879 3638 2517 1476 834 745 754 2359 1295 1065 2133 3464 MEAN 92.9 121 81.2 47.6 28.8 24.0 25.1 76.1 43.2 34.4 68.8 115 MAX 242 360 160 86 36 32 54 275 115 112 424 235 MIN 44 66 54 33 24 23 20 24 26 25 21 56 AC-FT 5710 7220 4990 2930 1650 1480 1500 4680 2570 2110 4230 6870 CFSM 5.05 6.59 4.41 2.59 1.56 1.31 1.37 4.14 2.35 1.87 3.74 6.28 IN. 5.82 7.36 5.09 2.98 1.69 1.51 1.52 4.77 2.62 2.15 4.31 7.00 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1960 - 2000, BY WATER YEAR (WY) MEAN 81.3 69.3 43.6 30.4 26.2 25.2 35.9 56.8 44.4 36.3 47.5 78.9 MAX 195 159 121 71.0 50.8 71.2 142 193 117 65.7 110 208 (WY) 1990 1969 1966 1997 1996 1972 1969 1963 1999 1981 1979 1998 MIN 25.4 25.1 18.1 14.7 13.2 11.0 9.70 12.4 15.6 9.18 15.9 25.0 (WY) 1963 1995 1998 1998 1965 1984 1984 1977 1994 1994 1994 1994 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1960 - 2000 ANNUAL TOTAL 25995 23159 ANNUAL MEAN 71.2 63.3 48.1 HIGHEST ANNUAL MEAN 71.7 1999 LOWEST ANNUAL MEAN 20.7 1994 HIGHEST DAILY MEAN 360 Nov 19 424 Aug 23 3260 Sep 22 1998 LOWEST DAILY MEAN 25 Mar 17 20 Apr 28 5.4 Aug 4 1994 ANNUAL SEVEN-DAY MINIMUM 27 May 20 21 Apr 24 6.4 Jul 29 1994 INSTANTANEOUS PEAK FLOW 1730 Oct 16 23500 Sep 22 1998 INSTANTANEOUS PEAK STAGE 9.69 Oct 16 21.24 Sep 22 1998 INSTANTANEOUS LOW FLOW 19 Apr 30 5.4 Aug 4 1994 ANNUAL RUNOFF (AC-FT) 51560 45940 34820 ANNUAL RUNOFF (CFSM) 3.87 3.44 2.61 ANNUAL RUNOFF (INCHES) 52.56 46.82 35.49 10 PERCENT EXCEEDS 122 132 86 50 PERCENT EXCEEDS 61 45 33 90 PERCENT EXCEEDS 30 23 16 e Estimated 116 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 117 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR. WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED SEDIMENT DISCHARGE: January 1968 to current year. INSTRUMENTATION.--US D-49 SEDIMENT SAMPLER SINCE OCTOBER 1968.SEDIMENT PUMPING SAMPLER SINCE 1990 EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATIONS: Maximum daily mean,20,400 mg/L November 27, 1968; minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily, 240,000 tons ( 218,000tonnes) September 22,1998; minimum daily, <0.01ton (<0.01tonne) several days during many years. EXTREMES FOR CURRENT YEAR 2000.-- SEDIMENT CONCENTRATIONS: Maximum daily mean,1,630 mg/L August 23,2000; minimum daily mean, 3 mg/L August 14, 2000. SEDIMENT LOADS: Maximum daily, 2,680 tons (2,431 tonnes) August 23,2000; minimum daily, .20 ton (.19 tonne) August 14,2000. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) OCT 28... 1245 87 157 8.0 25.0 3.3 7.7 97 <10 2000 K150 FEB 22... 1100 29 166 7.0 22.2 3.0 8.6 102 <10 K5 K7 MAR 31... 0950 27 151 7.8 21.5 140 8.6 101 <10 3300 8400 APR 24... 1310 24 162 7.5 26.8 7.5 7.6 98 <10 210 220 AUG 16... 1225 28 169 8.2 27.5 3.5 9.4 123 <10 K64 K45 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) OCT 28... 56 13.4 5.36 7.1 .4 1.6 49 <1.0 10.8 7.9 FEB 22... -- -- -- -- -- -- 56 -- -- -- MAR 31... 52 12.5 5.05 7.0 .4 1.9 -- <1.0 8.1 8.1 APR 24... 61 14.8 5.73 8.0 .5 2.0 49 <1.0 11.7 8.1 AUG 16... 60 14.6 5.81 7.5 .4 1.4 56 -- 11.2 7.6 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 28... <.1 11.5 87 20.4 10 1.09 .01 1.1 .02 -- FEB 22... -- -- -- -- <1 -- <.01 .8 .02 -- MAR 31... <.1 23.6 -- -- 109 .85 .02 .9 .05 .30 APR 24... <.1 25.0 105 6.86 2 -- <.01 .9 .02 -- AUG 16... <.1 24.2 106 7.93 <10 -- <.01 .4 .02 -- 118 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR.--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 28... <.20 -- -- .030 <3 29.4 E11 E.1 E1 <20 FEB 22... <.20 -- -- <.020 -- -- -- -- -- -- MAR 31... .35 1.2 5.4 .080 <3 55.0 <18 <.1 7 E12 APR 24... <.20 -- -- <.020 <3 29.4 E14 <.1 <1 <20 AUG 16... <.20 -- -- <.020 -- -- -- -- -- -- MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 28... 330 <1 23 <.3 <3 <1 <31 <.01 <4 .03 FEB 22... -- -- -- -- -- -- -- -- -- -- MAR 31... 3080 1 166 <.3 <3 <1 <31 .01 <4 <.04 APR 24... 310 <1 20 <.3 <3 <1 <31 <.01 6 <.02 AUG 16... -- -- -- -- -- -- -- -- -- -- SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 56 22 3.4 91 96 25 e75 e155 e58 2 54 9 1.4 156 754 785 e140 e145 e64 3 50 7 .95 125 281 100 e160 e754 e785 4 48 5 .67 122 332 151 e112 e209 e62 5 51 16 3.6 106 209 62 e130 e303 e122 6 64 95 20 85 129 30 e140 e303 e122 7 62 91 19 81 121 26 e120 e281 e100 8 54 48 7.5 100 252 122 e112 e209 e62 9 47 54 6.9 98 246 66 e92 e161 e60 10 44 43 5.1 e90 e114 e24 e86 e32 e7.4 11 106 632 606 e78 e114 e24 78 9 2.0 12 58 184 32 e68 e95 e20 74 9 1.8 13 77 155 58 e66 e95 e20 73 8 1.7 14 51 55 7.8 e74 e155 e58 70 8 1.5 15 49 46 6.3 e110 e632 e605 68 6 1.2 16 168 1160 2320 e113 e632 e605 66 6 1.1 17 122 403 218 e150 e716 e765 68 7 1.2 18 121 435 286 e210 e1160 e1860 64 7 1.3 19 83 168 39 e360 e1250 e2670 63 8 1.3 20 100 189 56 e280 e1160 e1860 62 8 1.4 21 100 183 55 e200 e1150 e1830 62 9 1.4 22 122 206 79 e145 e145 e64 66 7 1.3 23 128 303 122 e130 e281 e100 59 6 .96 24 95 162 43 e108 e246 e66 58 5 .85 25 242 1560 2540 e94 e246 e66 61 7 1.2 26 145 145 64 e88 e129 e30 56 10 1.6 27 103 70 20 e84 e168 e39 54 15 2.2 28 149 716 766 e76 e155 e58 56 22 3.4 29 93 95 25 e76 e155 e58 81 129 31 30 90 110 29 e74 e155 e58 56 44 6.7 31 147 578 395 --- --- --- 55 18 2.8 TOTAL 2879 --- 7835.62 3638 --- 12247 2517 --- 1510.31 119 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR.--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 53 18 2.6 33 9 .79 e24 e7 e.44 2 54 19 2.8 35 7 .70 e24 e7 e.45 3 67 74 14 34 6 .58 e24 e7 e.46 4 60 26 4.3 33 5 .46 e24 e7 e.46 5 62 41 10 32 5 .44 e24 e7 e.47 6 59 57 9.4 31 5 .45 e24 e7 e.48 7 55 21 3.3 31 6 .47 e24 e7 e.48 8 53 19 2.8 31 6 .48 e24 e8 e.49 9 54 22 3.2 30 7 .57 e23 e8 e.49 10 48 25 3.2 29 13 1.0 e24 e8 e.49 11 47 25 3.2 29 19 1.5 e23 e8 e.50 12 45 15 1.9 29 12 .92 e23 e8 e.50 13 48 9 1.2 29 7 .51 e23 e8 e.50 14 46 6 .73 28 4 .32 e24 e8 e.52 15 56 23 7.2 27 5 .35 e24 e8 e.54 16 86 161 60 26 6 .41 e24 e8 e.55 17 48 26 3.4 26 7 .47 e24 e9 e.56 18 44 10 1.2 26 7 .47 e24 e9 e.56 19 43 7 .83 26 6 .45 e24 e9 e.57 20 41 5 .60 26 6 .43 e24 e9 e.58 21 40 4 .47 25 6 .41 e23 e9 e.58 22 38 5 .56 e26 e6 e.43 e25 e9 e.60 23 38 7 .75 e28 e6 e.43 e24 e9 e.62 24 37 10 1.0 e36 e6 e.46 e25 e9 e.63 25 37 13 1.3 e27 e6 e.55 e24 e10 e.64 26 37 13 1.3 e26 e6 e.55 e23 e10 e.62 27 38 14 1.4 e26 e7 e.47 e24 e10 e.63 28 37 10 1.0 e25 e7 e.47 e23 e10 e.64 29 37 6 .60 e24 e7 e.45 e23 e10 e.63 30 35 6 .56 --- --- --- e23 e10 e.64 31 33 9 .80 --- --- --- e32 e10 e.77 TOTAL 1476 --- 145.60 834 --- 15.99 745 --- 17.09 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 e26 e11 e.83 24 12 .98 34 11 .99 2 e25 e11 e.74 26 24 1.7 33 10 .88 3 e24 e11 e.72 102 489 346 32 9 .83 4 e24 e11 e.72 105 438 257 31 9 .77 5 e25 e11 e.74 60 108 23 30 9 .76 6 e23 e9 e.52 49 73 25 30 10 .83 7 e22 e9 e.52 111 762 888 29 12 .91 8 e26 e12 e.76 162 516 349 28 13 .98 9 e23 e9 e.52 146 281 123 27 12 .88 10 e27 e12 e.81 62 92 16 26 11 .78 11 e26 e12 e.88 275 1250 2670 36 37 6.1 12 e24 e12 e.84 146 89 43 42 89 13 13 e22 e13 e.78 78 25 5.3 51 67 10 14 e21 e13 e.74 64 13 2.3 63 216 92 15 e21 e13 e.73 54 8 1.2 50 34 7.9 16 e21 e13 e.75 79 180 95 115 822 602 17 e22 e13 e.77 116 298 161 51 71 10 18 e22 e14 e.80 71 66 14 35 33 3.1 19 e23 e14 e.83 52 24 3.4 31 27 2.3 20 e21 e14 e.83 45 15 1.8 86 350 297 21 e54 e108 e23 47 9 1.1 83 251 80 22 e54 e108 e23 45 6 .74 41 43 4.8 23 e29 e24 e1.7 81 231 129 35 26 2.5 24 e24 e10 e.65 54 58 8.9 32 23 2.0 25 22 9 .52 47 30 3.8 31 20 1.7 26 22 8 .45 41 29 3.2 75 307 202 27 21 7 .38 40 34 4.0 42 51 5.8 28 20 7 .36 62 87 17 33 31 2.8 29 20 7 .40 41 49 5.5 32 19 1.6 30 20 8 .41 38 26 2.7 31 10 .82 31 --- --- --- 36 17 1.6 --- --- --- TOTAL 754 --- 65.70 2359 --- 5204.22 1295 --- 1356.03 120 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR.--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 30 10 .84 e24 e11 e.84 149 343 255 2 32 15 1.3 e28 e13 e1.0 122 71 32 3 29 13 1.0 e24 e6 e.33 81 10 2.1 4 36 28 3.7 e26 e6 e.33 148 507 439 5 30 27 2.2 e25 e6 e.33 147 486 248 6 50 89 35 e23 e6 e.33 108 211 62 7 46 59 8.5 e23 e6 e.33 94 71 19 8 30 29 2.4 e23 e6 e.33 102 192 86 9 112 647 548 e22 e6 e.33 98 194 65 10 48 38 6.3 e22 e6 e.33 83 91 21 11 39 18 2.6 e21 e5 e.30 66 44 7.9 12 e35 e35 e3.3 23 4 .26 62 21 3.6 13 e30 e11 e.84 22 4 .21 60 11 1.8 14 e29 e13 e1.0 21 3 .19 58 13 2.1 15 e27 e13 e1.0 22 6 .33 56 24 3.6 16 e26 e11 e.78 26 19 1.6 178 1560 2600 17 e26 e11 e.78 26 33 2.3 112 211 66 18 e25 e11 e.78 22 23 1.4 161 167 87 19 e39 e18 e2.6 22 15 .88 138 172 125 20 e28 e13 e1.0 22 10 .58 133 206 78 21 e39 e18 e2.6 21 5 .28 102 63 18 22 e27 e13 e1.0 33 527 78 235 1160 1860 23 e26 e11 e.78 424 1630 2680 167 203 91 24 e25 e11 e.78 145 280 200 146 158 69 25 e40 e51 e5.8 176 433 334 120 167 55 26 e30 e11 e.84 160 291 132 107 145 42 27 e26 e11 e.78 171 637 708 151 402 204 28 e30 e11 e.84 130 274 111 103 35 9.8 29 e25 e11 e.84 172 919 1140 92 18 4.5 30 e25 e11 e.84 131 247 93 85 17 4.0 31 e25 e11 e.84 103 79 29 --- --- --- TOTAL 1065 --- 639.86 2133 --- 5517.81 3464 --- 6561.4 YEAR 23159 41116.63 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- SEDI- SED. CHARGE, MENT, SUSP. INST. SEDI- DIS- SIEVE CUBIC MENT, CHARGE, DIAM. FEET SUS- SUS- % FINER DATE TIME PER PENDED PENDED THAN SECOND (MG/L) (T/DAY) .062 MM (00061) (80154) (80155) (70331) OCT 19... 0730 81 172 38 95 NOV 09... 0720 81 379 83 97 JAN 11... 0745 46 28 3.5 65 MAY 04... 1910 265 1870 1340 98 09... 0700 137 178 66 96 AUG 24... 1807 362 853 834 94 SEP 04... 1532 285 1040 800 96 121 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR.--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) MAY 04... 1750 257 3280 2280 35 52 77 07... 1920 751 7780 15800 28 38 54 11... 1445 1210 6860 22400 35 45 57 16... 1742 287 1500 1160 46 58 71 AUG 25... 1645 426 1860 2150 31 44 64 SEP 04... 1702 494 3840 5120 37 50 69 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) MAY 04... 92 98 100 100 100 100 100 07... 70 84 90 96 99 100 100 11... 67 74 79 87 95 99 100 16... 83 92 95 99 100 100 100 AUG 25... 79 92 94 98 100 100 100 SEP 04... 84 92 97 99 100 100 100 122 RIO GRANDE DE ARECIBO BASIN 50028400 RIO TANAMA AT CHARCO HONDO, PR LOCATION.--Lat 18°24'52", long 66°42'52", Hydrologic Unit 21010002 on right bank near to an abandoned power house at Charco Hondo, 1.5 mi (2.4 km) upstream from mouth, and 4 mi (6 km) south of Arecibo. DRAINAGE AREA.--22.2 mi2 (57.5 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--April 1969 to June 1971, October 1981 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 60 ft (18 m), from topographic map. REMARKS.--Records poor. Diversion 0.8 mi (1.3 km) upstream for municipal supply of Arecibo. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 121 426 e140 e120 e77 e64 69 54 e63 e57 50 e157 2 115 324 e290 e117 e78 e64 66 64 e62 e56 58 e186 3 98 268 e350 e146 e82 e65 64 110 e61 e56 51 e119 4 89 218 e240 e161 e78 e64 65 134 e60 e53 53 e164 5 85 210 e280 e158 e77 e64 66 118 e59 e60 53 e175 6 91 177 e300 e141 e74 e64 61 71 e58 e52 48 e150 7 158 155 e250 e118 e74 e63 60 122 e57 e90 48 e124 8 143 153 e240 e108 e74 e63 68 165 e57 e83 47 e120 9 99 168 215 e112 e73 e62 61 257 e56 e77 45 e123 10 88 149 207 e103 e71 e64 71 187 e56 e100 45 e126 11 138 147 181 e97 e70 e61 69 530 e55 e62 44 e113 12 140 127 168 e95 e70 e61 63 e411 e66 e65 43 e101 13 172 e123 158 e95 70 e63 60 e143 e81 e62 43 e97 14 230 e142 151 e99 70 e64 57 e104 e77 e60 44 e92 15 269 e216 145 e101 69 e63 55 e91 e89 e55 43 e95 16 408 228 139 e189 70 e63 54 93 e118 e53 45 e233 17 254 315 e144 e115 70 e64 57 175 e98 e53 51 e159 18 265 468 e133 e98 69 e64 57 190 e66 e54 43 e186 19 204 777 e135 e92 70 e63 60 100 e61 e84 42 e165 20 190 e577 e135 e90 70 e63 56 85 e61 e58 44 e169 21 207 e393 e134 e89 70 e62 e144 79 e143 e81 41 e137 22 291 e290 e150 e88 70 e66 e143 81 e78 e57 42 e342 23 209 e250 e136 e88 75 e63 e74 90 e63 e53 606 e256 24 180 e203 e132 e86 95 e65 e67 100 e60 e51 e181 e162 25 590 e181 e129 e86 71 e64 e63 80 e58 e82 e208 e146 26 503 e171 e124 e85 69 e62 e60 72 e83 e63 e196 e129 27 305 e160 e118 e83 68 e64 56 69 e81 e54 e209 e202 28 302 e150 e121 e84 67 e62 54 78 e63 e62 e182 e142 29 219 e140 e190 e82 65 e62 53 80 e57 e52 e201 e125 30 186 e140 e132 e85 --- e61 55 67 e56 e51 e172 e108 31 368 --- e126 e82 --- e85 --- 65 --- e52 e130 --- TOTAL 6717 7446 5493 3293 2106 1982 2008 4065 2103 1948 3108 4603 MEAN 217 248 177 106 72.6 63.9 66.9 131 70.1 62.8 100 153 MAX 590 777 350 189 95 85 144 530 143 100 606 342 MIN 85 123 118 82 65 61 53 54 55 51 41 92 AC-FT 13320 14770 10900 6530 4180 3930 3980 8060 4170 3860 6160 9130 CFSM 9.76 11.2 7.98 4.78 3.27 2.88 3.02 5.91 3.16 2.83 4.52 6.91 IN. 11.26 12.48 9.20 5.52 3.53 3.32 3.36 6.81 3.52 3.26 5.21 7.71 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2000, BY WATER YEAR (WY) MEAN 168 138 86.7 63.1 51.8 45.2 66.0 125 94.5 67.2 84.5 143 MAX 335 260 219 167 106 76.1 141 371 236 120 168 448 (WY) 1990 1982 1982 1997 1996 1999 1986 1986 1999 1969 1998 1998 MIN 72.1 50.4 36.4 22.3 16.8 16.6 25.9 15.8 23.3 22.0 35.1 44.9 (WY) 1983 1995 1989 1989 1989 1988 1989 1989 1989 1989 1994 1994 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1969 - 2000 ANNUAL TOTAL 51427 44872 ANNUAL MEAN 141 123 92.9 HIGHEST ANNUAL MEAN 133 1999 LOWEST ANNUAL MEAN 46.9 1994 HIGHEST DAILY MEAN 777 Nov 19 777 Nov 19 6400 Sep 22 1998 LOWEST DAILY MEAN 41 May 26 41 Aug 21 4.2 May 28 1989 ANNUAL SEVEN-DAY MINIMUM 51 Apr 17 44 Aug 9 5.4 May 22 1989 INSTANTANEOUS PEAK FLOW 3530 May 11 15000 May 18 1985 INSTANTANEOUS PEAK STAGE 12.00 May 11 24.56 Sep 22 1998 ANNUAL RUNOFF (AC-FT) 102000 89000 67310 ANNUAL RUNOFF (CFSM) 6.35 5.52 4.18 ANNUAL RUNOFF (INCHES) 86.17 75.19 56.86 10 PERCENT EXCEEDS 252 222 182 50 PERCENT EXCEEDS 117 85 67 90 PERCENT EXCEEDS 57 55 30 e Estimated 123 RIO GRANDE DE ARECIBO BASIN 50028400 RIO TANAMA AT CHARCO HONDO, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 124 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR LOCATION.--Lat 18°27'20", long 66°42'10", Hydrologic Unit 21010002, at bridge on unimproved road, about 500 ft (152 m) upstream from Central Cambalache, near Highway 2, 13.9 mi (22.4 km) downstream from Dos Bocas Reservoir, 1.9 mi (3.1 km) downstream from Río Tanamá junction, and 1.6 mi (2.6 km) southeast of Arecibo. DRAINAGE AREA.--200 mi2 (520 km2). PERIOD OF RECORD.--January 1963 to January 1965 (monthly measurements only), February 1965 to April 1969 (occasional measurements only), May 1969 to September 1983, October 1996 to current year. GAGE.--Water-stage recorder. Datum of gage is 3.73 ft (1.14 m) above mean sea level. REMARKS.--Records poor. Flow regulated by Lago Dos Bocas dam, 13.9 mi (22.4 km) upstream. Gage-height satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 642 2890 822 460 318 310 406 252 465 224 235 e555 2 510 1280 1620 556 297 266 414 261 382 215 214 e933 3 415 1530 2960 634 274 297 424 316 324 111 235 e568 4 584 1340 2050 763 213 382 272 807 366 77 279 e681 5 436 1040 1550 666 352 346 210 758 280 124 448 e437 6 603 994 1840 555 321 356 285 489 139 138 290 e323 7 695 866 1850 604 333 256 126 484 246 127 126 e830 8 669 672 1530 561 306 270 424 788 252 164 124 e259 9 468 698 1410 507 412 283 331 1410 268 193 170 e570 10 389 762 1450 543 523 286 287 1350 258 256 162 e917 11 566 813 1030 553 460 330 258 1300 239 389 98 e769 12 749 648 834 504 343 226 131 1630 237 261 72 e265 13 748 704 1060 552 337 147 116 896 146 153 99 e209 14 906 540 862 633 338 126 120 529 243 163 106 244 15 915 1260 841 478 326 118 110 469 410 108 164 320 16 878 1350 875 513 193 115 109 450 214 114 195 560 17 889 1130 784 567 166 241 198 601 723 265 243 574 18 1780 2690 760 410 306 123 289 774 344 90 258 493 19 1330 5690 802 277 313 114 178 702 379 117 133 504 20 1310 3740 939 480 313 113 148 706 208 232 118 692 21 1010 2480 766 481 338 220 199 413 277 212 180 738 22 1100 2040 760 388 330 154 363 193 307 328 306 1180 23 631 1840 714 349 189 114 301 188 276 183 1250 1110 24 621 1480 692 343 250 119 265 346 160 367 1360 1040 25 1130 1360 710 348 349 298 257 371 212 178 991 824 26 1100 1380 645 344 433 385 284 297 238 234 513 711 27 1000 1260 658 345 358 254 257 364 197 208 763 727 28 911 1320 553 337 297 193 307 431 123 261 635 791 29 723 1190 549 333 387 138 288 480 219 124 530 1100 30 628 882 754 351 --- 257 256 503 249 205 423 469 31 2220 --- 532 328 --- 419 --- 382 --- 249 386 --- TOTAL 26556 45869 33202 14763 9375 7256 7613 18940 8381 6070 11106 19393 MEAN 857 1529 1071 476 323 234 254 611 279 196 358 646 MAX 2220 5690 2960 763 523 419 424 1630 723 389 1360 1180 MIN 389 540 532 277 166 113 109 188 123 77 72 209 AC-FT 52670 90980 65860 29280 18600 14390 15100 37570 16620 12040 22030 38470 CFSM 4.28 7.64 5.36 2.38 1.62 1.17 1.27 3.05 1.40 .98 1.79 3.23 IN. 4.94 8.53 6.18 2.75 1.74 1.35 1.42 3.52 1.56 1.13 2.07 3.61 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2000, BY WATER YEAR (WY) MEAN 810 763 550 360 298 312 367 545 465 373 444 710 MAX 1577 1529 1327 651 425 627 641 1192 1220 854 1269 1866 (WY) 1971 2000 1982 1997 1997 1972 1983 1980 1979 1979 1979 1979 MIN 404 201 150 155 152 122 196 188 139 189 218 271 (WY) 1983 1998 1998 1973 1974 1998 1975 1977 1977 1997 1974 1997 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1969 - 2000 ANNUAL TOTAL 235992 208524 ANNUAL MEAN 647 570 508 HIGHEST ANNUAL MEAN 691 1979 LOWEST ANNUAL MEAN 290 1974 HIGHEST DAILY MEAN 5690 Nov 19 5690 Nov 19 15900 Aug 31 1979 LOWEST DAILY MEAN 96 Jan 20 72 Aug 12 56 Mar 28 1998 ANNUAL SEVEN-DAY MINIMUM 145 Feb 18 119 Aug 8 67 Mar 18 1998 INSTANTANEOUS PEAK FLOW 7870 Oct 31 Not determined Sep 22 1998 INSTANTANEOUS PEAK STAGE 11.37 Oct 31 19.28 Sep 22 1998 INSTANTANEOUS LOW FLOW 50 Feb 26 1974 ANNUAL RUNOFF (AC-FT) 468100 413600 368200 ANNUAL RUNOFF (CFSM) 3.23 2.85 2.54 ANNUAL RUNOFF (INCHES) 43.89 38.79 34.53 10 PERCENT EXCEEDS 1270 1210 982 50 PERCENT EXCEEDS 527 384 357 90 PERCENT EXCEEDS 195 147 136 e Estimated 125 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 126 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°27'20", long 66°42'10", Hydrologic Unit 21010002, at bridge on unimproved road, about 500 ft (152 m) upstream from Central Cambalache, near Highway 2, 10 mi (13.4 km) downstream from Dos Bocas Reservoir, 1.9 mi (3.1 km) downstream from Rio Tanamá , and 1.6 mi (2.6 km) southeast of Arecibo. DRAINAGE AREA.--200 mi2 (520 km2), approximately. PERIOD OF RECORD.--Water years 1963-66, 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) NOV 08... 0900 E574 243 7.9 24.3 38 7.1 85 14 410 360 FEB 09... 1000 250 275 8.0 23.3 2.6 8.0 94 <10 25 K150 MAR 29... 1240 120 324 8.1 27.0 1.5 8.8 110 <10 K110 K20 MAY 02... 1155 251 262 7.7 25.1 .6 7.6 92 <10 450 K50 AUG 08... 1200 116 277 8.0 28.7 1.4 10.6 138 <10 K140 K100 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) NOV 08... 100 33.3 5.10 7.6 .3 1.9 98 <1.0 10.4 8.8 FEB 09... -- -- -- -- -- -- 103 -- -- -- MAR 29... 140 46.5 6.00 8.7 .3 1.5 -- 1.6 9.9 11.8 MAY 02... 110 34.7 6.37 9.7 .4 1.6 107 <1.0 12.1 11.1 AUG 08... 120 37.6 5.90 8.1 .3 1.6 115 -- 11.2 11.1 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 08... <.1 18.2 144 -- 46 -- <.01 .9 .05 .16 FEB 09... -- -- -- -- 5 -- <.01 .9 .02 -- MAR 29... <.1 13.3 -- -- 2 -- <.01 .6 .02 -- MAY 02... <.1 17.0 156 106 2 -- <.01 .3 .03 -- AUG 08... <.1 16.2 160 50.2 <10 .02 .02 .04 .27 .93 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) NOV 08... .21 1.1 5.1 .080 <3 43.5 E14 .2 1 E11 FEB 09... <.20 -- -- <.020 -- -- -- -- -- -- MAR 29... <.20 -- -- <.020 <3 29.3 21 <.1 <1 <20 MAY 02... <.20 -- -- <.020 E2 28.7 20 <.1 E1 <20 AUG 08... 1.2 1.2 5.5 .160 -- -- -- -- -- -- 127 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 08... 1680 1 110 <.3 <3 <1 <31 <.01 5 .04 FEB 09... -- -- -- -- -- -- -- -- -- -- MAR 29... 110 <1 35 <.3 <3 <1 31 .01 <4 <.02 MAY 02... 150 <1 28 <.3 <3 <1 <31 <.01 5 <.02 AUG 08... -- -- -- -- -- -- -- -- -- -- CHLOR- DANE, P,P'- P,P'- ENDO- TECH- DDD P,P'- DDT DI- DI- SULFAN PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I DATE TOTAL TOTAL TOTAL RECOVER TOTAL RECOVER TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39516) (39330) (39350) (39360) (39365) (39370) (39570) (39380) (39388) NOV 08... -- -- -- -- -- -- -- -- -- FEB 09... -- -- -- -- -- -- -- -- -- MAR 29... -- -- -- -- -- -- -- -- -- MAY 02... <.1 <.013 <.1 <.014 <.016 <.017 <.02 <.009 <.015 AUG 08... -- -- -- -- -- -- -- -- -- ENDRIN HEPTA- METH- METHYL WATER HEPTA- CHLOR MALA- OXY- PARA- UNFLTRD ETHION, CHLOR, EPOXIDE LINDANE THION, CHLOR, THION, MIREX, DATE REC TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39390) (39398) (39410) (39420) (39340) (39530) (39480) (39600) (39755) NOV 08... -- -- -- -- -- -- -- -- -- FEB 09... -- -- -- -- -- -- -- -- -- MAR 29... -- -- -- -- -- -- -- -- -- MAY 02... <.014 <.01 <.011 <.009 <.012 <.03 <.01 <.01 <.01 AUG 08... -- -- -- -- -- -- -- -- -- CARBO- PHENO- PCNS PARA- PER- TOX- THION UNFILT THION, THANE APHENE, WATER 2,4-D, 2,4,5-T 2,4-DP SILVEX, DATE RECOVER TOTAL TOTAL TOTAL UNFLTRD TOTAL TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39250) (39540) (39034) (39400) (39786) (39730) (39740) (82183) (39760) NOV 08... -- -- -- -- -- -- -- -- -- FEB 09... -- -- -- -- -- -- -- -- -- MAR 29... -- -- -- -- -- -- -- -- -- MAY 02... <.1 <.01 <.1 <1 <.01 <.05 <.03 <.04 <.03 AUG 08... -- -- -- -- -- -- -- -- -- THIS PAGE IS INTENTIONALLY BLANK 128 18°27 30
 18°15
66°32 30
 66°20
de de Río Río Río Río Río Río Río Río Lago de Matrullas Lago Guineo Caño Tiburones Grande Grande Cialitos Toro Negro Manatí Manatí Matrullas Sana Muertos Bauta Orocovis Laguna Tortuguero QUALITY-OF-WATER STATION AND NUMBER 0340 0307 210 032290 EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER SURFACE-WATER STATION AND NUMBER CAÑO TIBURONES FLOW DIRECTION TUNNEL FLOW DIRECTION DRAINAGE BASIN BOUNDARY TOWN OR CITY Figure 14. Río Grande de Manatí basin. 129 BARCELONETA MANATÍ VEGA BAJA VEGA ALTA ATLANTIC OCEAN JAYUYA OROCOVIS VILLALBA BARRANQUITAS CIALES MOROVIS COROZAL Basin area PUERTO RICO FLORIDA 0 0 1 1 2 2 3 3 4 4 5 MILES 5 KILOMETERS 030460 0307 0312 0350 035950 0355 0381 0382 0340 210 1077 1076 206 207 166 032290 032590 130 RIO GRANDE DE MANATI BASIN 50030460 RIO OROCOVIS AT OROCOVIS, PR LOCATION.--Lat 18°13'25", long 66°23'34", Hydrologic Unit 21010001, on right bank, 0.4 mi (0.6 km) south of junction of Highways 155 and 156 in Orocovis, 2.1 mi (3.38 km) upstream from Río Botijas, and 250 ft (76 m) upstream from bridge on Highway 599. DRAINAGE AREA.--5.03 mi2 (13.03 km2). PERIOD OF RECORD.--April 1981 to September 1982, October 1988 to current year. GAGE.--Water-stage recorder. Elevation of gage is 500 ft (152 m), from topographic map. REMARKS.--Records poor. Low flow affected by diversions for water supply. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e22 16 18 10 6.1 5.3 3.0 e2.1 e2.0 2.1 4.0 e2.2 2 e17 42 26 11 5.9 4.7 2.7 e2.1 e1.9 2.5 2.5 e2.1 3 14 26 24 25 5.9 4.4 3.0 e7.8 e1.8 2.4 2.5 e2.3 4 13 16 17 23 5.7 4.4 2.7 e6.0 e1.8 e2.3 3.2 e3.3 5 11 25 41 18 5.6 4.1 2.7 e4.1 e1.8 e2.2 2.1 e7.5 6 9.6 20 40 23 5.5 3.9 2.7 e2.6 e1.7 e2.2 1.7 e4.4 7 13 15 31 20 5.4 3.5 2.6 e2.2 1.8 e2.2 1.6 e3.0 8 11 e14 30 14 5.2 3.3 2.6 e9.9 2.1 e2.2 1.8 e2.5 9 9.0 e12 21 12 5.1 3.2 2.8 e7.1 2.2 e2.2 2.2 e2.2 10 9.7 12 18 11 4.8 3.2 2.2 e5.2 2.2 e1.9 2.0 e2.4 11 9.2 8.9 17 9.9 5.0 3.4 2.3 e35 2.4 e1.8 2.3 e3.1 12 9.3 e8.1 16 9.4 4.8 3.3 2.6 e34 3.8 e1.8 1.8 e2.7 13 9.7 e9.1 15 11 4.7 3.1 2.5 e24 3.5 e1.8 1.7 e2.4 14 8.7 13 14 11 4.6 3.0 2.5 e12 3.4 e1.8 2.5 e2.1 15 e11 20 13 18 4.7 2.9 2.3 e8.5 3.3 e1.7 e2.4 e1.8 16 52 46 13 25 4.3 2.9 2.4 e5.0 6.2 e1.7 e1.6 e1.6 17 e23 179 13 15 4.1 3.0 2.5 4.7 2.5 e2.1 e1.5 e28 18 e13 219 13 13 3.9 2.9 2.4 4.2 2.3 e2.3 e1.5 e112 19 e19 140 14 12 3.9 2.8 2.6 8.7 2.0 e2.0 e1.6 e21 20 27 72 14 11 3.8 2.8 2.8 7.3 1.7 e1.9 e1.6 e6.2 21 36 47 14 11 3.5 2.8 2.9 4.2 1.8 e2.0 e1.6 e46 22 36 38 16 11 5.2 3.6 2.2 3.2 1.7 e1.9 e26 e58 23 23 34 e13 11 11 3.3 2.3 2.6 1.7 e1.9 e134 e32 24 28 30 14 10 32 3.4 2.3 2.4 2.0 e1.8 e7.5 e11 25 59 27 e13 9.8 22 3.1 2.3 e2.2 2.0 e1.7 e3.3 e6.2 26 26 25 12 9.0 9.4 2.9 2.2 e2.1 2.0 e1.7 e3.6 e4.5 27 16 22 11 9.0 7.6 2.9 2.2 e2.0 2.1 e1.6 e3.4 e3.8 28 13 22 13 7.4 6.5 4.3 e2.1 e2.0 1.9 e1.6 e2.6 e4.5 29 10 20 17 7.2 6.0 3.8 e2.1 e2.2 1.9 2.2 e2.3 e3.9 30 9.5 18 12 7.1 --- 2.8 e2.2 e2.0 1.9 2.2 e2.2 e3.2 31 33 --- 11 6.2 --- 4.5 --- e2.0 --- 1.8 e2.0 --- TOTAL 600.7 1196.1 554 401.0 202.2 107.5 74.7 219.4 69.4 61.5 230.6 385.9 MEAN 19.4 39.9 17.9 12.9 6.97 3.47 2.49 7.08 2.31 1.98 7.44 12.9 MAX 59 219 41 25 32 5.3 3.0 35 6.2 2.5 134 112 MIN 8.7 8.1 11 6.2 3.5 2.8 2.1 2.0 1.7 1.6 1.5 1.6 AC-FT 1190 2370 1100 795 401 213 148 435 138 122 457 765 CFSM 3.85 7.93 3.55 2.57 1.39 .69 .50 1.41 .46 .39 1.48 2.56 IN. 4.44 8.85 4.10 2.97 1.50 .80 .55 1.62 .51 .45 1.71 2.85 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1981 - 2000, BY WATER YEAR (WY) MEAN 17.2 10.4 6.73 6.53 4.35 1.95 5.12 13.5 4.99 3.22 4.70 24.9 MAX 58.0 39.9 17.9 34.3 15.7 3.47 21.0 45.9 17.1 9.07 12.3 83.0 (WY) 1990 2000 2000 1992 1996 2000 1993 1995 1999 1996 1989 1998 MIN 1.95 .93 .53 .77 .96 .90 .93 .86 .88 .88 1.03 .88 (WY) 1994 1998 1998 1995 1995 1994 1995 1997 1994 1994 1982 1994 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1981 - 2000 ANNUAL TOTAL 4929.27 4103.0 ANNUAL MEAN 13.5 11.2 8.56 HIGHEST ANNUAL MEAN 13.3 1999 LOWEST ANNUAL MEAN 1.49 1994 HIGHEST DAILY MEAN 219 Nov 18 219 Nov 18 1570 Sep 10 1996 LOWEST DAILY MEAN .98 Jul 28 1.5 Aug 17 .20 Oct 4 1992 ANNUAL SEVEN-DAY MINIMUM 1.1 Jul 26 1.7 Aug 15 .33 Oct 11 1992 INSTANTANEOUS PEAK FLOW 955 Oct 25 8890 Sep 10 1996 INSTANTANEOUS PEAK STAGE 9.35 Oct 25 17.38 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 9780 8140 6200 ANNUAL RUNOFF (CFSM) 2.68 2.23 1.70 ANNUAL RUNOFF (INCHES) 36.46 30.34 23.11 10 PERCENT EXCEEDS 33 25 15 50 PERCENT EXCEEDS 3.9 4.3 2.1 90 PERCENT EXCEEDS 1.3 1.9 .83 e Estimated 131 RIO GRANDE DE MANATI BASIN 50030460 RIO OROCOVIS AT OROCOVIS, PR--Continued O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 132 RIO GRANDE DE MANATI BASIN 50030700 RIO OROCOVIS NEAR OROCOVIS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°14'20", long 66°22'58", at flat low bridge about 300 ft (91 m) northwest of Highway 568, 1.0 mi (1.6 km) north of Orocovis plaza. DRAINAGE AREA.--10.1 mi2 (26.2 km2). PERIOD OF RECORD.--Water year 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) OCT 25... 1210 E20 233 8.3 23.3 17 7.5 94 <10 5000 2400 FEB 15... 1130 13 304 8.5 21.3 2.9 8.2 97 <10 210 28 APR 18... 1135 9.8 337 8.4 22.3 1.8 8.6 104 <10 K1500 530 SEP 05... 1425 8.0 309 7.9 26.8 22 7.1 95 <10 5100 790 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) OCT 25... 100 24.6 10.1 11.2 .5 2.4 97 <1.0 7.4 12.3 FEB 15... -- -- -- -- -- -- 125 -- -- -- APR 18... 130 33.2 12.4 12.0 .5 1.5 134 <1.0 7.7 15.9 SEP 05... 120 30.9 11.1 12.5 .5 1.9 120 -- 7.6 15.7 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 25... <.1 32.6 159 -- 32 .91 .01 .9 .03 .17 FEB 15... -- -- -- -- 6 1.19 .01 1.2 .03 -- APR 18... .1 38.4 201 5.30 2 1.29 .01 1.3 .04 -- SEP 05... .1 33.1 185 3.99 23 1.29 .01 1.3 .04 -- NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 25... .20 1.1 5.0 .080 <3 64.0 E16 <.1 1 <20 FEB 15... <.20 -- -- .180 -- -- -- -- -- -- APR 18... <.20 -- -- .120 <3 53.0 22 <.1 E1 <20 SEP 05... <.20 -- -- .170 -- -- -- -- -- -- 133 RIO GRANDE DE MANATI BASIN 50030700 RIO OROCOVIS NEAR OROCOVIS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 25... 650 <1 50 <.3 <3 <1 <31 <.01 5 .02 FEB 15... -- -- -- -- -- -- -- -- -- -- APR 18... 90 <1 12 <.3 <3 <1 <31 <.01 5 <.02 SEP 05... -- -- -- -- -- -- -- -- -- -- 134 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR LOCATION.--Lat 18°17'45", long 66°24'47", Hydrologic Unit 21010001, on right bank,0.1 mi (0.2 km) downstream from Quebrada Perchas, 0.8 mi (1.3 km) upstream from Río Sana Muerto, and 2.2 mi (3.5 km) south of Morovis. DRAINAGE AREA.--55.2 mi2 (143.0 km2). PERIOD OF RECORD.--January 1965 to current year. GAGE.--Water-stage recorder and concrete control. Elevation of gage is 440 ft (134 m), from topographic map. Feb.2,1966 to Apr.27,1967, staff gage read twice daily. REMARKS.--Records poor. Public water-supply pumped, about 1000 ft. (305 m) above the station, influences low-flow discharges. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e274 e227 184 159 105 72 46 28 25 19 13 22 2 e150 e341 997 159 100 68 43 30 26 17 29 22 3 e120 e259 485 330 99 64 45 35 26 18 18 23 4 e110 e139 241 356 96 60 42 55 25 17 20 191 5 e105 e131 662 244 94 61 40 58 24 16 19 137 6 e100 e149 551 268 89 63 40 38 23 15 13 53 7 e130 118 387 283 89 59 38 33 22 15 12 38 8 e140 110 355 202 91 59 36 55 22 15 11 31 9 e110 110 263 178 86 58 35 82 21 14 10 51 10 e98 145 230 164 83 56 36 58 21 14 11 28 11 e94 125 210 154 84 57 35 e89 20 13 11 23 12 e100 109 196 149 83 56 38 e83 26 13 10 22 13 e96 120 186 158 82 55 35 e74 59 13 9.4 18 14 e98 141 179 161 79 55 34 e55 28 14 9.2 17 15 e100 251 173 150 77 52 32 e48 25 13 17 18 16 e280 289 e168 310 75 51 34 e45 52 13 14 28 17 e400 969 e168 165 73 53 37 e46 73 13 12 35 18 e200 1450 e162 148 77 51 33 e41 32 19 10 206 19 e150 1020 e163 139 76 48 32 e36 25 13 9.9 116 20 e300 487 e164 134 77 47 42 48 25 12 11 71 21 e400 319 e165 128 73 48 98 37 24 12 10 122 22 e480 259 e185 125 109 57 92 32 22 12 16 178 23 190 231 e183 122 201 48 53 43 20 12 517 148 24 165 212 e170 118 170 47 39 39 19 11 104 96 25 288 194 e175 116 170 45 33 36 21 11 49 63 26 197 187 e174 114 100 45 34 33 22 11 45 46 27 149 175 e163 110 100 55 30 28 23 11 44 42 28 130 295 175 108 86 46 29 28 20 10 35 40 29 118 209 222 115 75 79 28 28 18 12 28 37 30 110 207 180 113 --- 47 30 28 18 15 25 33 31 e217 --- 167 105 --- 44 --- 28 --- 14 27 --- TOTAL 5599 8978 8083 5285 2799 1706 1219 1397 807 427 1169.5 1955 MEAN 181 299 261 170 96.5 55.0 40.6 45.1 26.9 13.8 37.7 65.2 MAX 480 1450 997 356 201 79 98 89 73 19 517 206 MIN 94 109 162 105 73 44 28 28 18 10 9.2 17 AC-FT 11110 17810 16030 10480 5550 3380 2420 2770 1600 847 2320 3880 CFSM 3.27 5.42 4.72 3.09 1.75 1.00 .74 .82 .49 .25 .68 1.18 IN. 3.77 6.05 5.45 3.56 1.89 1.15 .82 .94 .54 .29 .79 1.32 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1965 - 2000, BY WATER YEAR (WY) MEAN 151 144 112 83.0 64.5 62.7 101 152 60.9 45.1 53.1 111 MAX 1037 491 522 228 179 226 412 915 173 157 435 432 (WY) 1971 1971 1966 1997 1969 1972 1969 1985 1987 1979 1979 1996 MIN 24.0 11.4 8.65 10.4 15.3 12.7 8.80 15.7 6.75 5.54 9.70 6.87 (WY) 1978 1995 1995 1995 1994 1984 1995 1994 1994 1994 1984 1994 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1965 - 2000 ANNUAL TOTAL 49093 39424.5 ANNUAL MEAN 135 108 94.8 HIGHEST ANNUAL MEAN 248 1971 LOWEST ANNUAL MEAN 24.2 1994 HIGHEST DAILY MEAN 1450 Nov 18 1450 Nov 18 17100 May 18 1985 LOWEST DAILY MEAN 26 Apr 22 9.2 Aug 14 3.5 May 1 1995 ANNUAL SEVEN-DAY MINIMUM 27 Apr 18 10 Aug 8 4.0 Jul 22 1994 INSTANTANEOUS PEAK FLOW 3670 Dec 2 48000 May 18 1985 INSTANTANEOUS PEAK STAGE 6.19 Dec 2 17.89 May 18 1985 ANNUAL RUNOFF (AC-FT) 97380 78200 68690 ANNUAL RUNOFF (CFSM) 2.44 1.95 1.72 ANNUAL RUNOFF (INCHES) 33.08 26.57 23.34 10 PERCENT EXCEEDS 253 224 173 50 PERCENT EXCEEDS 91 58 49 90 PERCENT EXCEEDS 43 14 20 e Estimated 135 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR--Continued O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 136 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR. WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1968 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- CHARGE, SPE- WATER DIS- DEMAND, FORM, INST. CIFIC WHOLE SOLVED CHEM- FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) OCT 27... 1210 146 236 8.0 26.2 18 7.6 96 <10 K1200 FEB 15... 1340 77 282 8.7 24.5 2.1 8.2 101 <10 K82 APR 19... 1000 32 301 8.0 24.8 2.5 8.8 108 <10 K64 AUG 30... 1050 23 310 7.8 27.5 .8 7.8 101 <10 K100 STREP- ANC TOCOCCI HARD- MAGNE- SODIUM POTAS- WATER FECAL, NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE KF AGAR TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- (COLS. (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED DATE PER AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L 100 ML) CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) (31673) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) OCT 27... 3700 97 22.8 9.70 10.8 .5 2.3 91 <1.0 8.4 FEB 15... K2 -- -- -- -- -- -- 115 -- -- APR 19... 300 120 27.7 11.5 13.5 .5 1.9 119 -- 6.8 AUG 30... K91 110 27.7 11.0 12.6 .5 2.8 108 -- 9.4 SOLIDS, RESIDUE CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- RIDE, RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) (00940) (00950) (00955) (70301) (70302) (00530) (00615) (00630) (00610) (00605) OCT 27... 13.7 <.1 28.1 150 59.3 21 <.01 1.0 .03 .20 FEB 15... -- -- -- -- -- 5 <.01 1.0 .02 -- APR 19... 16.3 .1 30.4 179 15.3 1 <.01 .6 .02 -- AUG 30... 17.4 .1 28.9 175 10.9 <10 <.01 .7 .04 -- NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 27... .23 1.2 5.4 .070 <3 49.4 24 <.1 1 <20 FEB 15... <.20 -- -- .070 -- -- -- -- -- -- APR 19... <.20 -- -- .060 <3 47.3 23 <.1 E1 <20 AUG 30... <.20 -- -- .060 -- -- -- -- -- -- 137 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR.--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 27... 980 <1 44 <.3 <3 <1 <31 <.01 8 .02 FEB 15... -- -- -- -- -- -- -- -- -- -- APR 19... 110 <1 16 <.3 <3 <1 <31 <.01 <4 <.02 AUG 30... -- -- -- -- -- -- -- -- -- -- 138 RIO GRANDE DE MANATI BASIN 50032290 LAGO EL GUINEO AT DAMSITE NEAR VILLALBA, PR LOCATION.--Lat 18°09'41", long 66°31'36", Hydrologic Unit 21010001, at damsite on Río Toro Negro, 3.0 mi (4.8 km) northwest from Villalba plaza and 1.9 mi (3.1 km) northeast of Cerro Maravillas. The reservoir itself fixes the territorial limits between the Municipality of Ciales and Orocovis. DRAINAGE AREA.--1.64 mi2 (4.25 km2). ELEVATION RECORDS PERIOD OF RECORD.--May 1988 to current year. Prior to October 1994, published as Lago El Guineo at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago El Guineo was completed in 1931. It provides a maximum storage of approximately 2,180 ac-ft (2.688 hm3) for power and irrigation. Waters are discharged through an outlet power tunnel into the Río Toro Negro and coveyed to the head water works of Toro Negro Hydroelectric Plant No.2, for energy generation at Toro Negro Hydroelectric plant No.1, and are discharged into the Guayabal Reservoir to be later used for irrigation at South Coast Irrigation System. The dam is rockfill with a vertical concrete corewall, rock toes, and riprap facing of upstream slope, with a total length of 565 ft (172 m), a maximum structural height of 125 ft (38 m) to top of corewall. At a maximum reservoir water surface elevation the uncontrolled morning-glory tunnel spillway crest has an elevation of 2,960 ft (902 m) above mean sea level and a design capacity of 7,000 ft3/s. The dam is owned by Puerto Rico Electric Power Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,964.40 ft (903.55 m), Sept, 22 1998; minimun elevation, 2,919.79 ft (899.95 m), May 27, 1988. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 2,961.57 ft (902.69 m), Oct.11; minimun elevation, 2,931.47 ft (893.51 m), Aug.22. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 2,872 0 2,950 1,308 2,919 361 2,961 1,852 2,925 491 2,966 2,180 2,943 1,029 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2960.77 2960.18 2959.96 2957.90 2958.03 2950.85 2939.78 2935.41 2947.35 2943.16 2932.75 2943.57 2 2960.70 2960.23 2959.74 2957.92 2957.99 2950.21 2939.75 2935.32 2946.92 2943.21 2932.71 2944.13 3 2960.70 2960.20 2959.50 2958.00 2957.96 2949.66 2939.10 A 2946.99 2942.69 2932.65 2944.57 4 2960.70 2960.05 2959.67 2958.04 2957.51 2949.60 2938.46 A 2947.05 2942.71 2932.61 2945.59 5 2960.70 2960.34 2959.16 2958.09 2957.09 2949.54 2937.74 A 2946.61 2942.18 2932.54 2946.73 6 2960.72 2960.62 2959.33 2958.11 2956.44 2949.02 2936.97 A 2946.14 2941.55 2932.46 2947.12 7 2960.76 2960.72 2958.97 2958.13 2956.43 2948.29 2936.22 A 2945.65 2940.89 2932.43 2946.92 8 2960.72 2960.43 2958.65 2958.15 2956.39 2948.06 2936.17 A 2945.17 2940.91 2932.38 2946.40 9 2960.70 2960.17 2958.28 2958.14 2956.34 2947.52 2936.08 A 2944.69 2940.92 2932.31 2946.40 10 2960.70 2960.35 2957.88 2958.14 2956.30 2946.78 2935.93 A 2944.72 2940.38 2932.27 2946.40 11 2960.79 2960.50 2957.80 2958.13 2955.90 2946.72 2935.65 A 2944.75 2939.94 2932.21 2946.42 12 2960.75 2960.24 2957.41 2958.13 2955.86 2946.62 2935.56 A 2944.52 2939.47 2932.13 2945.89 13 2960.73 2960.57 2957.01 2958.13 2955.81 2945.85 2935.48 A 2945.34 2938.92 2932.04 2945.43 14 2960.71 2960.70 2956.66 2958.13 2955.34 2945.61 2935.40 A 2946.53 2938.23 2931.98 2944.83 15 2960.71 2960.83 2956.72 2958.28 2954.87 2944.95 2935.33 A 2946.27 2938.23 2931.99 2944.38 16 2960.78 2960.84 2956.80 2958.37 2954.38 2944.28 2934.83 A 2946.41 2938.22 2931.95 2944.26 17 2960.75 2961.07 2956.90 2958.34 2953.89 2944.20 2933.42 A 2946.59 2938.24 2931.88 2943.93 18 2960.72 2961.14 2956.96 2958.32 2953.40 2944.12 2933.92 A 2946.73 2937.42 2931.79 A 19 2960.72 2960.89 2957.03 2958.30 2953.38 2944.04 2934.92 A 2946.32 2936.56 2931.71 A 20 2960.73 2960.77 2957.10 2958.29 2953.32 2943.96 2935.71 A 2946.04 2935.69 2931.63 A 21 2960.73 2960.66 2957.18 2958.28 2953.26 2943.88 2935.83 A 2945.54 2934.79 2931.52 A 22 2960.71 2960.69 2957.27 2958.26 2952.80 2943.79 2935.85 A 2945.09 2934.77 2935.19 A 23 2960.76 2960.64 2957.33 2958.23 2952.74 2943.68 2935.83 2947.81 2944.69 2934.74 2940.70 2950.32 24 2960.72 2960.57 2957.39 2958.21 2952.30 2943.00 2935.81 2947.50 2944.80 2933.71 2940.94 2950.78 25 2960.77 2960.74 2957.43 2958.20 2951.99 2942.93 2935.76 2947.32 2944.85 2933.71 2941.58 2950.66 26 2960.74 2960.73 2957.47 2958.16 2951.95 2942.27 29 A 35.70 2947.49 2944.44 2932.93 2941.79 2950.72 27 2960.49 2960.73 2957.50 2958.14 2951.91 2941.60 2935.64 2947.60 2944.00 2932.88 2941.91 2951.55 28 2960.23 2960.72 2957.57 2958.12 2951.43 2941.71 2935.58 2947.79 2943.55 2932.84 2942.01 2951.58 29 2960.03 2960.38 2957.82 2958.11 2951.38 2941.24 2935.52 2947.97 2943.10 2932.83 2942.20 2951.93 30 2959.92 2960.19 2957.84 2958.08 --- 2940.56 2935.46 2947.66 2943.13 2932.80 2942.35 2951.24 31 2960.29 --- 2957.88 2958.05 --- 2939.74 --- 2947.76 --- 2932.73 2942.43 --- MAX 2960.79 2961.14 2959.96 2958.37 2958.03 2950.85 2939.78 2947.97 2947.35 2943.21 2942.43 2951.93 MIN 2959.92 2960.05 2956.66 2957.90 2951.38 2939.74 2933.42 2935.32 2943.10 2932.73 2931.52 2943.57 A No gage-height record 139 RIO GRANDE DE MANATI BASIN 50032290 LAGO EL GUINEO AT DAMSITE NEAR VILLALBA, PR--Continued O N D 1999 J F M A M J J A S 2000 2930 2935 2940 2945 2950 2955 2960 2965 ELEVATION, IN FEET Gap indicates missing record 140 RIO GRANDE DE MANATI BASIN 50032590 LAGO DE MATRULLAS AT DAMSITE NEAR OROCOVIS, PR LOCATION.--Lat 18°12'46", long 66°28'50", Hydrologic Unit 21010001, in shelter house at damsite, and 5.8 mi (9.3 km) southwest of Orocovis. DRAINAGE AREA.--4.46 mi2 (11.55 km2). ELEVATION RECORDS PERIOD OF RECORD.--May 1988 to current year. Prior to October 1994, published as Lago de Matrullas at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Matrullas was completed in 1934. The dam is an earthfill structure about 120 ft (37 m) height, a top width of 30 ft (9 m) and a length of 710 ft (216 m), and has a maximum storage capacity of about 4,274 ac-ft (5.220 hm3) at top of dam elevation. The Matrullas Dam is owned by the Puerto Rico Electric Power Authority and is part of the Toro Negro Hydroelectric Project; a project developed by the P.R.E.P.A. for the primary purpose of generating electric power. Discharges from the Power Plants are collected by the Jacaguas River which flows into Guayabal Dam, at which dam they are regulated for irrigation of lands served by the Juana Díaz Canal. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,419.90 ft (737.58 m), Sept. 10, 1996; minimum elevation, 2,375.55 ft (724.06 m), Sept. 24, 25, 1994. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 2,416.87 ft (736.66 m), Nov. 18; minimum elevation, 2,409.65 ft (734.46 m), May 3. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 2,338 2 2,399 1,845 2,360 302 2,420 3,331 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2415.64 A 2415.57 2415.55 2415.31 2415.26 2412.19 2410.00 2414.99 A A A 2 2415.55 A 2415.91 2415.58 2415.31 2415.18 2412.35 2409.79 2414.86 A A A 3 2415.51 A 2415.61 2415.58 2415.30 2415.08 2412.17 2410.05 2415.02 A A 2415.25 4 2415.42 A 2415.62 2415.64 2415.29 2414.93 2411.97 2412.07 2415.18 A A 2415.32 5 2415.41 A 2415.74 2415.51 2415.27 2414.69 2411.79 2412.44 2415.03 A A 2415.56 6 2415.45 A 2415.60 2415.59 2415.23 2414.53 2411.59 2412.65 2414.89 A A 2415.37 7 2415.56 A 2415.64 2415.58 2415.24 2414.40 2411.42 2413.23 2414.73 A A 2415.38 8 2415.43 A 2415.60 2415.58 2415.21 2414.29 2411.55 2414.18 2414.58 A A 2415.43 9 2415.51 A 2415.58 2415.56 2415.18 2414.17 2411.69 2415.17 2414.42 A A 2415.43 10 2415.52 A 2415.56 2415.57 2415.15 2414.05 2411.58 2415.26 2414.56 A A 2415.44 11 2415.40 A 2415.46 2415.41 2415.11 2414.22 2411.42 2415.69 2414.71 A A 2415.25 12 2415.52 2415.50 2415.53 2415.35 2415.32 2414.04 2411.24 2415.69 2414.65 A A 2415.10 13 2415.43 2415.56 2415.52 2415.39 2415.22 2413.93 2411.06 2415.49 2414.57 A A 2414.99 14 2415.41 2415.62 2415.51 2415.37 2415.19 2413.80 2410.87 2415.48 2414.55 A A 2414.85 15 2415.49 2415.79 2415.50 2415.79 2415.15 2413.66 2410.99 2415.31 2414.41 A A 2414.71 16 2415.86 2415.88 2415.49 2415.61 2415.10 2413.52 2410.94 2415.24 2415.41 A A 2414.85 17 2415.76 2416.58 2415.50 2415.58 2415.05 2413.38 2410.71 2415.40 2415.41 A A 2414.88 18 2415.95 2416.74 2415.59 2415.43 2415.00 2413.17 2410.48 2415.30 2415.40 2413.62 A 2415.47 19 2416.55 2416.15 2415.61 2415.41 2415.21 2412.96 2410.41 2415.33 A 2413.22 A 2415.02 20 2416.46 2415.93 2415.50 2415.40 2415.38 2412.81 2410.37 2415.28 A 2413.52 A 2414.44 21 2416.68 2415.83 2415.53 2415.36 2415.47 2412.67 2410.56 2415.11 A 2413.23 A 2415.37 22 2416.48 2415.79 2415.51 2415.34 2415.51 2412.88 2410.71 2415.03 A 2413.19 A 2415.81 23 2416.33 2415.73 2415.51 2415.50 2415.53 2412.75 2410.84 2415.18 A 2413.19 A 2415.65 24 2416.27 2415.70 2415.57 2415.41 2415.94 2412.63 2410.65 2415.13 A 2413.61 A 2415.60 25 2416.81 2415.71 2415.59 2415.39 2415.56 2412.77 2410.47 2415.05 A 2413.30 A 2415.49 26 2416.75 2415.64 2415.59 2415.40 2415.60 2412.63 2410.28 2415.00 A A A 2415.48 27 2416.67 2415.67 2415.46 2415.39 2415.57 2412.45 2410.09 2415.19 A A A 2415.46 28 A 2415.66 2415.46 2415.38 2415.40 2412.35 2409.92 2415.35 A A A 2415.53 29 A 2415.59 2415.47 2415.37 2415.32 2412.22 2410.06 2415.41 A A A 2415.46 30 A 2415.66 2415.42 2415.35 --- 2412.06 2410.21 2415.26 A A A 2415.31 31 A --- 2415.40 2415.31 --- 2412.00 --- 2415.13 --- A A --- MAX 2416.81 2416.74 2415.91 2415.79 2415.94 2415.26 2412.35 2415.69 2415.41 2413.62 --- 2415.81 MIN 2415.40 2415.50 2415.40 2415.31 2415.00 2412.00 2409.92 2409.79 2414.41 2413.19 --- 2414.44 A No gage-height record 141 RIO GRANDE DE MANATI BASIN 50032590 LAGO DE MATRULLAS AT DAMSITE NEAR OROCOVIS, PR--Continued O N D 1999 J F M A M J J A S 2000 2409 2410 2411 2412 2413 2414 2415 2416 2417 ELEVATION, IN FEET Gap indicates missing record 142 RIO GRANDE DE MANATI BASIN 50034000 RIO BAUTA NEAR OROCOVIS, PR LOCATION.--Lat 18°14'10", long 66°27'18", Hydrologic Unit 21010001, on left bank, at bridge on Highway 157 (12.1 km), and 4.2 mi (6.8 km) west of Orocovis. DRAINAGE AREA.--16.7 mi2 (43.3 km2). PERIOD OF RECORD.--February 1959 to April 1966 (annual low-flow measurements only), February to September 1969 (occasional measurements only), October 1969 to September 1982, October 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 772.82 ft (235.55 m) above mean sea level. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e58 e250 78 34 22 36 28 e8.1 13 10 12 13 2 e58 e140 188 34 22 33 15 e14 13 11 11 13 3 e52 e210 137 57 23 29 14 e59 13 11 9.3 14 4 e51 e110 79 78 22 29 12 110 12 9.8 11 16 5 e50 e82 117 73 22 29 11 76 12 9.6 10 41 6 e50 e94 138 69 21 28 10 27 12 9.5 8.3 32 7 e66 e80 104 71 21 24 10 29 11 9.5 8.4 19 8 e100 e64 102 55 21 22 10 192 11 9.4 8.8 15 9 e70 e66 84 e46 20 21 10 206 11 9.2 8.0 13 10 e54 e65 73 e41 20 21 10 123 11 8.7 8.0 13 11 e52 73 66 e38 19 20 10 145 10 8.3 7.9 19 12 e60 67 59 e35 18 20 11 183 12 8.3 7.7 15 13 e56 88 56 e40 18 20 9.8 104 13 8.2 7.7 13 14 e50 89 53 e38 18 18 9.3 60 13 8.1 11 12 15 e52 116 50 43 18 18 8.6 39 13 7.9 10 12 16 e100 227 46 83 18 17 9.1 31 25 7.8 8.8 12 17 e230 615 46 51 18 17 9.9 30 24 9.6 8.1 18 18 e150 780 42 41 18 17 9.0 27 16 10 7.8 289 19 e70 504 45 39 18 17 8.8 34 15 8.9 7.9 98 20 e110 239 47 35 18 16 e25 39 14 8.8 8.0 44 21 e170 147 47 34 17 16 e45 29 14 9.0 7.6 101 22 e220 115 59 e32 24 24 e20 23 13 8.4 33 158 23 e110 100 49 e31 63 16 e14 23 12 8.2 297 118 24 e80 89 46 e30 157 16 e12 22 13 7.8 56 70 25 e130 85 46 e29 117 15 e10 19 13 7.8 25 44 26 e131 78 42 e27 71 15 e9.9 18 12 7.6 24 36 27 e100 71 38 26 58 14 e9.2 16 11 7.5 25 31 28 e70 66 43 25 46 16 e9.1 16 11 7.4 17 35 29 e64 62 54 27 37 26 e8.9 15 10 10 15 34 30 e58 102 43 26 --- 16 e8.8 16 10 10 13 27 31 e300 --- 39 23 --- 33 --- 14 --- 8.1 12 --- TOTAL 2972 4874 2116 1311 985 659 387.4 1747.1 393 275.4 704.3 1375 MEAN 95.9 162 68.3 42.3 34.0 21.3 12.9 56.4 13.1 8.88 22.7 45.8 MAX 300 780 188 83 157 36 45 206 25 11 297 289 MIN 50 62 38 23 17 14 8.6 8.1 10 7.4 7.6 12 AC-FT 5890 9670 4200 2600 1950 1310 768 3470 780 546 1400 2730 CFSM 5.74 9.73 4.09 2.53 2.03 1.27 .77 3.37 .78 .53 1.36 2.74 IN. 6.62 10.86 4.71 2.92 2.19 1.47 .86 3.89 .88 .61 1.57 3.06 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2000, BY WATER YEAR (WY) MEAN 84.1 56.2 29.9 22.0 17.2 15.3 26.6 49.5 20.3 15.7 21.6 115 MAX 392 205 108 83.4 43.5 59.9 80.2 179 78.6 104 152 1104 (WY) 1971 1971 1971 1992 1998 1972 1980 1981 1979 1979 1979 1996 MIN 14.6 7.12 4.29 3.66 5.70 4.18 4.92 4.24 3.59 3.22 3.97 3.55 (WY) 1994 1995 1995 1995 1994 1994 1995 1994 1994 1994 1994 1994 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1969 - 2000 ANNUAL TOTAL 19232.8 17799.2 ANNUAL MEAN 52.7 48.6 39.5 HIGHEST ANNUAL MEAN 117 1996 LOWEST ANNUAL MEAN 6.56 1994 HIGHEST DAILY MEAN 780 Nov 18 780 Nov 18 19500 Sep 10 1996 LOWEST DAILY MEAN 8.9 May 29 7.4 Jul 28 2.8 Jul 23 1994 ANNUAL SEVEN-DAY MINIMUM 9.9 May 23 7.8 Jul 22 2.8 Jul 23 1994 INSTANTANEOUS PEAK FLOW 996 Nov 18 28200 Sep 22 1998 INSTANTANEOUS PEAK STAGE 10.14 Nov 18 25.93 Sep 22 1998 INSTANTANEOUS LOW FLOW 6.1 Aug 10 2.6 Jul 26 1994 ANNUAL RUNOFF (AC-FT) 38150 35300 28620 ANNUAL RUNOFF (CFSM) 3.16 2.91 2.37 ANNUAL RUNOFF (INCHES) 42.84 39.65 32.14 10 PERCENT EXCEEDS 110 110 69 50 PERCENT EXCEEDS 26 24 14 90 PERCENT EXCEEDS 14 9.0 5.6 e Estimated 143 RIO GRANDE DE MANATI BASIN 50034000 RIO BAUTA NEAR OROCOVIS, PR--Continued O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 144 RIO GRANDE DE MANATI BASIN 50035000 RIO GRANDE DE MANATI AT CIALES, PR LOCATION.--Lat 18°19'26", long 66°27'36", Hydrologic Unit 21010001, on left bank, 1.6 mi (2.6 km) upstream from Hwy 145 bridge, 0.8 mi (1.3 km) downstream from Quebrada Saliente, 0.9 mi (1.4 km) upstream from Quebrada Cojo Valés, and 1.2 mi (1.9 km) southeast of Ciales. DRAINAGE AREA.--128 mi2 (332 km2), excludes 6.0 mi2 (15.5 km2), the runoff from which is diverted through El Guineo and Matrullas reservoirs. PERIOD OF RECORD.--September 1946 to September 1953, May 1956 to December 1957 (unpublished, available in files of Caribbean District Office and in the National Water Data Storage and Retrieval System, Washington, D.C.); February 1959 to September 1960 (monthly discharge measurements only); October 1960 to current year. Equivalent record from January 1971 to December 1972 published as 50035200 Río Grande de Manatí at Highway 145 at Ciales at site 1.6 mi (2.6 km) downstream, drainage area 132 mi2 (342 km2). GAGE.--Water-stage recorder. Elevation of gage is 140 ft (43 m), from topographic map. Prior to Apr. 1, 1962, staff gage, read twice daily, at site 100 ft (30 m) upstream at same datum. January 1971 to December 1972 at site 1.6 mi (2.6 km) downstream at different datum. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate gage heights of major floods, pointed out by local residents are as follows: August 1899, 50 ft (15 m), September 1928, 36 ft (11 m), and September 1932, 34 ft (10 m) at site 1.6 mi (2.6 km) upstream. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 438 719 545 327 198 134 e88 e54 e92 e56 e57 44 2 417 1200 4100 324 188 e130 e82 e86 e97 e56 e75 80 3 318 797 1510 621 188 e120 e86 e130 e97 e54 e68 55 4 282 499 591 759 182 e110 e81 e300 e95 e56 e64 219 5 261 507 1520 584 175 e120 e76 e520 e89 e54 e57 195 6 249 485 1480 534 172 e130 e76 e160 e85 e52 e55 132 7 561 407 865 649 169 e120 e72 e130 e82 e52 e52 86 8 410 382 817 436 165 e110 e69 e370 86 e51 e48 70 9 274 395 634 379 157 e110 e67 898 84 e50 e44 78 10 268 409 537 342 154 e100 e68 570 87 e50 e48 65 11 293 406 476 321 152 e110 e67 519 89 e48 e48 58 12 313 353 437 303 148 e100 e73 685 95 e49 e43 51 13 264 392 414 313 148 e100 e66 472 116 e48 e41 50 14 256 429 394 324 147 e100 e65 287 107 e52 e40 59 15 273 693 376 301 144 e98 e60 242 104 e49 e74 59 16 1200 1020 362 630 141 e96 e66 214 105 e46 e60 70 17 746 3940 375 354 139 e110 e71 273 150 e45 e49 74 18 459 6340 354 307 144 e98 e62 272 92 e50 e40 545 19 405 4070 381 280 141 e91 e61 213 e76 e52 39 370 20 883 1700 384 266 140 e90 e81 222 e71 e47 41 288 21 1020 903 399 247 137 e91 e190 186 e71 e54 39 426 22 911 706 491 252 176 e110 e180 176 e67 e57 49 574 23 466 584 431 240 425 e92 e90 259 e63 e56 800 604 24 391 516 410 238 443 e90 e72 229 e59 e52 205 383 25 789 464 442 227 430 e86 e63 193 e59 e48 94 275 26 548 441 401 225 202 e85 e66 188 e62 e49 87 e180 27 385 403 357 222 179 e110 e57 150 e64 e50 71 e170 28 340 625 e350 212 154 e88 e55 138 e60 e49 57 e160 29 313 493 e509 215 137 e150 e53 133 e57 e53 51 e150 30 310 598 396 211 --- e90 e57 120 e56 e65 50 e130 31 1490 --- 349 202 --- e84 --- e110 --- e63 51 --- TOTAL 15533 30876 21087 10845 5475 3253 2320 8499 2517 1613 2597 5700 MEAN 501 1029 680 350 189 105 77.3 274 83.9 52.0 83.8 190 MAX 1490 6340 4100 759 443 150 190 898 150 65 800 604 MIN 249 353 349 202 137 84 53 54 56 45 39 44 AC-FT 30810 61240 41830 21510 10860 6450 4600 16860 4990 3200 5150 11310 CFSM 3.91 8.04 5.31 2.73 1.47 .82 .60 2.14 .66 .41 .65 1.48 IN. 4.51 8.97 6.13 3.15 1.59 .95 .67 2.47 .73 .47 .75 1.66 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1946 - 2000, BY WATER YEAR (WY) MEAN 424 355 267 196 167 135 249 403 157 104 149 315 MAX 2422 1029 1296 679 1393 477 1174 2293 512 438 1212 1295 (WY) 1971 2000 1966 1952 1950 1969 1969 1985 1999 1979 1979 1996 MIN 91.9 34.7 29.7 26.2 41.6 29.7 28.5 29.6 17.8 14.1 27.0 23.9 (WY) 1994 1995 1995 1995 1957 1994 1984 1994 1994 1994 1994 1994 145 RIO GRANDE DE MANATI BASIN 50035000 RIO GRANDE DE MANATI AT CIALES, PR--Continued SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1946 - 2000 ANNUAL TOTAL 143074 110315 ANNUAL MEAN 392 301 244 HIGHEST ANNUAL MEAN 520 1971 LOWEST ANNUAL MEAN 47.3 1994 HIGHEST DAILY MEAN 6340 Nov 18 6340 Nov 18 42700 May 18 1985 LOWEST DAILY MEAN 72 May 25 39 Aug 19 8.5 Jul 28 1994 ANNUAL SEVEN-DAY MINIMUM 78 May 20 45 Aug 8 9.5 Jul 24 1994 INSTANTANEOUS PEAK FLOW 17700 Dec 2 128000 Sep 10 1996 INSTANTANEOUS PEAK STAGE 12.50 Dec 2 25.20 Sep 10 1996 INSTANTANEOUS LOW FLOW 8.5 Jul 27 1994 ANNUAL RUNOFF (AC-FT) 283800 218800 177100 ANNUAL RUNOFF (CFSM) 3.06 2.35 1.91 ANNUAL RUNOFF (INCHES) 41.58 32.06 25.94 10 PERCENT EXCEEDS 779 586 450 50 PERCENT EXCEEDS 209 150 115 90 PERCENT EXCEEDS 101 52 50 e Estimated O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 146 RIO GRANDE DE MANATI BASIN 50035500 RIO GRANDE DE MANATI AT HIGHWAY 149 AT CIALES, RP WATER-QUALITY RECORDS LOCATION.--Lat 18°20'46", long 66°28'06", at bridge on Highway 149, about 800 ft (244 m) upstream from confluence with Río Cialitos, 0.5 mi (0.8 km) north of Ciales plaza. DRAINAGE AREA.--136 mi2 (352 km2) this excludes the 6 mi2 (15.5 km2) upstream from Lago El Guineo and Lago de Matrullas, flow from which is diverted to Río Jacaguas. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) OCT 27... 1445 433 207 8.1 27.7 13 7.1 91 <10 K5000 2100 FEB 28... 1330 268 235 8.0 23.5 17 8.2 97 <10 K730 25 MAY 08... 0815 E600 175 7.5 23.4 42 7.0 83 >10 K10000 K11000 SEP 05... 0930 E300 186 7.3 25.2 300 7.5 92 24 26000 50000 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) OCT 27... 82 20.8 7.40 10.0 .5 1.9 82 <1.0 8.0 11.3 FEB 28... -- -- -- -- -- -- 89 -- -- -- MAY 08... 66 17.0 5.73 8.4 .4 1.7 64 <1.0 7.0 8.7 SEP 05... 66 15.9 6.34 7.9 .4 2.4 63 -- 7.9 10.9 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 27... <.1 27.0 135 158 23 .84 .02 .9 .04 .28 FEB 28... -- -- -- -- 9 -- <.01 1.0 .07 -- MAY 08... .1 21.3 108 -- 67 .62 .02 .6 .06 .27 SEP 05... .2 19.8 109 -- 682 .86 .04 .9 .09 1.3 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 27... .32 1.2 5.2 .070 <3 43.3 21 <.1 E1 <20 FEB 28... <.20 -- -- .080 -- -- -- -- -- -- MAY 08... .33 .97 4.3 .150 <3 50.5 31 <.1 2 <20 SEP 05... 1.4 2.3 10.2 .460 -- -- -- -- -- -- 147 RIO GRANDE DE MANATI BASIN 50035500 RIO GRANDE DE MANATI AT HIGHWAY 149 AT CIALES, RP--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 27... 760 <1 47 <.3 <3 <1 <31 <.01 <4 .03 FEB 28... -- -- -- -- -- -- -- -- -- -- MAY 08... 2100 E1 131 <.3 <3 <1 <31 <.01 <4 <.04 SEP 05... -- -- -- -- -- -- -- -- -- -- 148 RIO GRANDE DE MANATI BASIN 50035950 RIO CIALITOS AT HIGHWAY 649 AT CIALES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°20'18", long 66°28'28", 100 ft (30 m) upstream from bridge on Highway 649, 0.7 mi (1.1 km) upstream from mouth, and about 0.4 mi (0.6 km) west of Ciales plaza. DRAINAGE AREA.--17.0 mi2 (44.0 km2). PERIOD OF RECORD.--Water years 1969-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) OCT 25... 1515 E350 118 7.4 24.4 660 7.7 93 17 K100000 81000 FEB 28... 1520 30 226 8.1 23.2 6.5 8.1 95 <10 >6000 45 MAY 08... 1020 68 151 7.4 23.5 94 8.1 97 19 K14000 K14000 SEP 05... 1150 26 173 7.3 26.0 70 7.9 99 12 K7500 K14000 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) OCT 25... 53 16.5 2.91 5.6 .3 2.4 51 <1.0 5.4 5.9 FEB 28... -- -- -- -- -- -- 87 -- -- -- MAY 08... 56 15.7 3.95 6.5 .4 1.9 51 <1.0 5.2 8.9 SEP 05... 63 18.1 4.43 7.5 .4 1.8 58 -- 5.7 8.1 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 25... <.1 13.0 82 -- 725 .82 .04 .9 .13 2.9 FEB 28... -- -- -- -- 6 -- <.01 .9 .05 -- MAY 08... .1 18.6 91 16.8 154 .83 .02 .9 .07 .66 SEP 05... <.1 19.1 100 7.09 86 1.08 .02 1.1 .07 .36 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 25... 3.0 3.9 17.1 .870 <3 236 E15 .1 3 <20 FEB 28... <.20 -- -- .080 -- -- -- -- -- -- MAY 08... .73 1.6 7.0 .210 <3 80.2 28 <.1 4 E12 SEP 05... .43 1.5 6.8 .160 -- -- -- -- -- -- 149 RIO GRANDE DE MANATI BASIN 50035950 RIO CIALITOS AT HIGHWAY 649 AT CIALES, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 25... 10500 8 989 <.3 <3 <1 42 <.01 5 <.16 FEB 28... -- -- -- -- -- -- -- -- -- -- MAY 08... 3780 1 190 <.3 <3 <1 <31 <.01 <4 <.04 SEP 05... -- -- -- -- -- -- -- -- -- -- 150 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR LOCATION.--Lat 18°25'52", long 66°31'37", Hydrologic Unit 21010002, at bridge on Highway 2, and 2.3 mi (3.7 km) west of Manatí. DRAINAGE AREA.--197 mi2 (510 km2), approximately, of which about 38 mi2 (98 km2) is partly or entirely noncontributing, excludes 6.0 mi2 (15.5 km2) upstream from Lago El Guineo and Lago de Matrullas. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1963-68 (annual maximum discharge only), February 1970 to current year. REVISED RECORDS.--WRD PR-86-1: 1970-71 (M), 1975, 1979, 1982-85 (P). GAGE.--Water-stage recorder. Elevation of gage is 14 ft (4 m), from topographic map. Prior to 1968 crest-stage gage at same site and datum 3.57 ft (1.09 m) lower. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. Possible water extraction about 500 ft (152.4 m) upstream of gage by unknown source affecting low flow. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate gage heights to gage datum of major floods, pointed out by local residents, are as follows: Sept. 13, 1928, 36.6 ft (11.16 m), Sept. 27, 1932, 36.3 ft (11.06 m), and Aug. 4, 1945, 34.3 ft (10.45 m). DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 633 1990 1280 771 300 298 159 128 165 98 82 132 2 636 1190 9340 749 294 287 147 130 160 99 87 176 3 525 1870 10000 1100 290 276 142 184 160 97 102 149 4 482 793 1660 1440 289 267 143 395 155 100 103 200 5 460 747 2370 1070 285 261 138 781 150 95 96 408 6 449 854 3730 703 281 256 135 237 145 91 89 220 7 668 636 1840 1110 276 248 132 191 141 91 82 164 8 892 578 1850 622 276 238 129 488 138 90 78 143 9 492 588 1400 542 270 229 125 1380 138 89 77 136 10 465 550 1220 478 267 222 122 1070 139 88 78 136 11 474 606 1090 448 265 217 122 650 131 86 79 123 12 550 528 1020 426 262 210 125 1120 130 86 77 113 13 475 573 954 418 259 204 123 605 157 86 74 102 14 460 607 909 456 259 198 119 331 167 92 72 94 15 477 1110 869 409 255 193 116 278 154 86 74 96 16 1390 1310 835 862 251 189 112 243 141 82 88 99 17 2140 4570 836 465 248 190 113 266 212 81 80 107 18 938 10300 804 408 251 184 114 323 154 89 75 568 19 616 9300 810 381 256 178 112 239 134 93 72 438 20 1200 3710 816 367 251 170 117 233 125 84 73 302 21 1680 2180 819 358 247 166 169 218 125 96 73 643 22 1980 1600 931 350 273 171 225 203 118 90 74 1050 23 877 1340 918 342 499 171 155 210 112 82 2490 1180 24 706 1200 850 338 711 160 137 351 106 80 641 491 25 1220 1100 876 333 872 158 130 226 104 79 289 329 26 1200 1050 869 330 419 149 126 210 109 78 224 270 27 693 975 792 325 367 151 124 193 114 78 207 251 28 597 1010 775 317 344 148 123 183 106 77 174 237 29 555 1240 1060 323 315 163 125 180 101 77 153 232 30 518 947 892 322 --- 160 128 178 98 88 139 210 31 2780 --- 797 311 --- 162 --- 175 --- 88 146 --- TOTAL 27228 55052 53212 16874 9432 6274 3987 11599 4089 2716 6248 8799 MEAN 878 1835 1717 544 325 202 133 374 136 87.6 202 293 MAX 2780 10300 10000 1440 872 298 225 1380 212 100 2490 1180 MIN 449 528 775 311 247 148 112 128 98 77 72 94 AC-FT 54010 109200 105500 33470 18710 12440 7910 23010 8110 5390 12390 17450 CFSM 4.46 9.32 8.71 2.76 1.65 1.03 .67 1.90 .69 .44 1.02 1.49 IN. 5.14 10.40 10.05 3.19 1.78 1.18 .75 2.19 .77 .51 1.18 1.66 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1970 - 2000, BY WATER YEAR (WY) MEAN 728 580 427 274 211 182 340 640 244 154 214 627 MAX 2958 1835 1717 879 444 521 1037 3178 815 577 1644 3732 (WY) 1971 2000 2000 1997 1988 1972 1993 1985 1999 1979 1979 1998 MIN 154 71.0 55.1 59.1 72.0 56.2 49.9 93.7 63.8 53.0 67.9 67.4 (WY) 1995 1995 1998 1995 1994 1994 1995 1989 1994 1994 1984 1994 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1970 - 2000 ANNUAL TOTAL 249520 205510 ANNUAL MEAN 684 562 384 HIGHEST ANNUAL MEAN 756 1971 LOWEST ANNUAL MEAN 96.5 1994 HIGHEST DAILY MEAN 10300 Nov 18 10300 Nov 18 80400 Sep 22 1998 LOWEST DAILY MEAN 127 May 27 72 Aug 14 31 Jan 24 1995 ANNUAL SEVEN-DAY MINIMUM 135 May 21 76 Aug 9 33 Jul 23 1994 INSTANTANEOUS PEAK FLOW 43300 Dec 2 198000 Sep 10 1996 INSTANTANEOUS PEAK STAGE 31.77 Dec 2 36.39 Sep 10 1996 INSTANTANEOUS LOW FLOW 69 Aug 14 28 Jan 23 1995 ANNUAL RUNOFF (AC-FT) 494900 407600 278100 ANNUAL RUNOFF (CFSM) 3.47 2.85 1.95 ANNUAL RUNOFF (INCHES) 47.12 38.81 26.48 10 PERCENT EXCEEDS 1390 1110 685 50 PERCENT EXCEEDS 306 250 168 90 PERCENT EXCEEDS 147 89 82 151 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 10,000 20,000 50,000 100,000 DISCHARGE, IN CUBIC FEET PER SECOND 152 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR. WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) NOV 01... 1225 1890 170 7.5 24.2 290 7.5 89 18 28000 22000 FEB 28... 1040 350 271 7.7 22.8 45 7.6 88 <10 K110 40 APR 27... 1145 124 322 7.6 28.6 2.5 6.5 84 <10 K11000 K140 AUG 28... 1315 171 288 7.4 30.0 15 6.1 81 <10 2900 4500 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) NOV 01... 62 17.8 4.39 7.1 .4 1.8 62 <1.0 6.2 7.8 FEB 28... -- -- -- -- -- -- 105 -- -- -- APR 27... 140 42.4 8.04 10.8 .4 1.9 134 <1.0 8.7 13.7 AUG 28... 110 32.7 7.49 10.6 .4 2.0 108 -- 9.4 12.4 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 01... <.1 7.1 89 456 585 .88 .03 .9 .09 1.3 FEB 28... -- -- -- -- 63 1.08 .02 1.1 .09 .13 APR 27... .1 20.8 187 62.8 11 .98 .01 1.0 .03 .22 AUG 28... <.1 21.5 161 74.3 19 .95 .02 1.0 .12 .44 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) NOV 01... 1.4 2.3 10.2 .620 E1 197 E17 .9 19 64 FEB 28... .22 1.3 5.8 .110 -- -- -- -- -- -- APR 27... .25 1.2 5.5 .080 <3 51.5 19 <.1 1 <20 AUG 28... .56 1.5 6.8 .100 -- -- -- -- -- -- 153 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR.--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 01... 18800 13 934 <.3 <3 <1 57 <.01 6 <.08 FEB 28... -- -- -- -- -- -- -- -- -- -- APR 27... 620 <1 78 <.3 <3 <1 <31 <.01 <4 <.02 AUG 28... -- -- -- -- -- -- -- -- -- -- 154 LAGUNA TORTUGUERO BASIN 50038200 LAGUNA TORTUGUERO OUTLET NEAR VEGA BAJA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°28'29", long 66°26'50", at bridge on Highway 686, 4.2 mi (6.8 km) northeast of Manatí, and 4.4 mi (7.1 km) northwest of Vega Baja plaza. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1964-66, 1969-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 PH OXYGEN, COLI- STREP- SPE- WATER DIS- FORM, TOCOCCI CIFIC WHOLE SOLVED FECAL, FECAL, CON- FIELD TEMPER- OXYGEN, (PER- 0.7 KF AGAR DUCT- (STAND- ATURE DIS- CENT UM-MF (COLS. DATE TIME ANCE ARD WATER SOLVED SATUR- (COLS./ PER (US/CM) UNITS) (DEG C) (MG/L) ATION) 100 ML) 100 ML) (00095) (00400) (00010) (00300) (00301) (31625) (31673) OCT 15... 1355 1080 7.1 30.0 6.4 85 190 91 FEB 17... 1340 808 8.0 27.0 7.4 93 K8 K48 APR 27... 1300 966 7.9 30.0 4.8 63 K26 80 AUG 17... 1115 1190 7.7 30.5 4.9 66 580 280 ANC RESIDUE NITRO- WATER TOTAL NITRO- NITRO- GEN,AM- NITRO- UNFLTRD AT 105 GEN, GEN, MONIA + GEN, PHOS- CARBON, FET DEG. C, AMMONIA NITRITE ORGANIC NO2+NO3 PHORUS ORGANIC FIELD SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE MG/L AS PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L CACO3 (MG/L) AS N) AS N) AS N) AS N) AS P) AS C) (00410) (00530) (00610) (00615) (00625) (00630) (00665) (00680) OCT 15... 120 3 .33 .02 1.2 .4 <.020 8.2 FEB 17... 143 <1 .29 .02 .81 1.1 <.020 -- APR 27... 116 <1 .41 .02 1.1 .6 <.020 7.7 AUG 17... 105 <10 .39 .02 1.6 .3 <.020 -- 18°27 30
 18°15
66°30
66°15
Río Río Río Río Río Río Dos Corozal Bocas Cibuco Río Río Río Río Río de los Negros Mavilla Mavilla Indio Cibuco Cibuco Morovis MOROVIS Laguna Tortuguero Unibón 038320 QUALITY-OF-WATER STATION AND NUMBER 038320 213 EXPLANATION WELL AND WELL NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SURFACE-WATER STATION AND NUMBER Figure 15. Río Cibuco basin. 155 MANATÍ VEGA BAJA VEGA ALTA TOA ALTA DORADO Basin area PUERTO RICO TOA BAJA ATLANTIC OCEAN OROCOVIS CIALES COROZAL COMERÍO NARANJITO 0 0 1 1 2 2 3 3 4 4 5 MILES 5 KILOMETERS 0395 0382 038320 70 212 211 1102 1101 1103 213 156 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR LOCATION.--Lat l8°21'13", long 66°20'07", Hydrologic Unit 21010001, on right bank, 150 ft (46 m) downstream from junction with Río Corozal, and 1.4 mi (2.3 km) northwest of Corozal. DRAINAGE AREA.--15.1 mi2 (39.1 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--May 1969 to current year. GAGE.--Water-stage recorder. Elevation of gage is 195 ft (59 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. Daily discharge affected by sewage treatment plant about 0.6 mi (1.0 km) upstream from station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e30 e55 e350 45 e30 23 13 7.3 9.8 8.4 5.4 16 2 e28 e162 e1280 45 e28 22 13 7.5 10 8.2 5.2 14 3 e26 e61 e920 143 e27 21 14 8.6 10 8.0 9.7 14 4 e25 e52 e135 104 e28 20 14 10 9.7 8.6 7.6 35 5 e23 e134 e289 60 26 20 14 9.9 9.6 7.2 5.3 24 6 e21 e47 e280 91 25 19 12 8.7 9.4 7.2 4.5 15 7 e20 e34 e149 64 26 19 13 13 9.4 6.8 4.9 13 8 e24 e31 e137 58 25 19 12 31 9.5 7.4 4.5 34 9 e36 e30 e94 52 24 19 11 15 9.2 6.4 4.3 39 10 e24 e50 e80 44 24 19 11 9.5 9.0 6.4 5.8 16 11 e22 e29 e73 41 24 18 12 237 9.8 6.2 5.8 13 12 e20 e27 e66 41 23 17 13 29 22 6.4 5.0 12 13 e24 e39 e60 53 23 17 17 17 14 5.9 4.4 11 14 e23 e174 e56 46 24 17 14 14 11 6.4 4.5 11 15 e20 e293 e54 44 23 17 11 13 11 5.5 4.5 11 16 e669 e236 e50 47 23 18 11 14 44 5.1 4.6 11 17 e75 e358 e54 36 23 20 11 20 17 5.6 4.7 53 18 e46 e402 e49 34 25 18 10 14 12 5.6 4.6 39 19 e193 e254 e52 e33 24 17 10 13 11 5.9 5.1 80 20 165 e150 e48 33 22 16 9.8 12 11 5.4 4.9 28 21 e209 e110 60 32 24 16 9.7 11 10 5.1 4.4 18 22 e109 e98 76 34 29 17 9.2 11 9.2 4.9 7.4 55 23 87 e75 67 33 31 15 8.4 11 8.9 4.8 148 24 24 e71 e68 61 33 27 15 8.2 11 8.9 4.4 28 17 25 e310 e58 75 33 40 14 7.8 11 8.8 4.5 27 14 26 e122 e60 57 32 25 13 7.7 11 16 4.3 28 13 27 e47 e58 47 29 31 15 7.5 10 11 4.3 18 13 28 e35 e110 61 e28 24 16 7.3 10 9.3 4.4 14 12 29 e31 e128 68 e37 23 16 7.5 10 8.8 4.7 12 11 30 e29 e110 49 e36 --- 14 7.7 11 8.6 4.5 18 12 31 e77 --- 47 e31 --- 13 --- 10 --- 4.4 17 --- TOTAL 2641 3493 4944 1472 751 540 326.8 620.5 357.9 182.9 427.1 678 MEAN 85.2 116 159 47.5 25.9 17.4 10.9 20.0 11.9 5.90 13.8 22.6 MAX 669 402 1280 143 40 23 17 237 44 8.6 148 80 MIN 20 27 47 28 22 13 7.3 7.3 8.6 4.3 4.3 11 AC-FT 5240 6930 9810 2920 1490 1070 648 1230 710 363 847 1340 CFSM 5.64 7.71 10.6 3.14 1.72 1.15 .72 1.33 .79 .39 .91 1.50 IN. 6.51 8.61 12.18 3.63 1.85 1.33 .81 1.53 .88 .45 1.05 1.67 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2000, BY WATER YEAR (WY) MEAN 42.5 49.8 40.6 25.6 21.6 20.8 30.9 42.6 15.2 12.4 16.3 33.8 MAX 135 155 169 69.6 51.3 65.1 111 157 44.4 35.6 50.8 191 (WY) 1991 1971 1971 1992 1988 1981 1973 1986 1987 1999 1979 1996 MIN 8.05 5.63 1.94 6.93 7.75 4.36 3.32 3.20 1.63 2.19 3.44 3.88 (WY) 1979 1998 1998 1995 1994 1984 1984 1977 1994 1994 1978 1994 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1969 - 2000 ANNUAL TOTAL 18296.0 16434.2 ANNUAL MEAN 50.1 44.9 29.4 HIGHEST ANNUAL MEAN 56.5 1971 LOWEST ANNUAL MEAN 7.47 1994 HIGHEST DAILY MEAN 1280 Dec 2 1280 Dec 2 3070 Sep 10 1996 LOWEST DAILY MEAN 7.6 Apr 20 4.3 Jul 26 .91 Jul 17 1994 ANNUAL SEVEN-DAY MINIMUM 7.9 Apr 16 4.4 Jul 24 1.2 Jun 21 1994 INSTANTANEOUS PEAK FLOW 12500 Oct 16 20400 Nov 9 1995 INSTANTANEOUS PEAK STAGE 19.67 Oct 16 22.35 Nov 9 1995 ANNUAL RUNOFF (AC-FT) 36290 32600 21330 ANNUAL RUNOFF (CFSM) 3.32 2.97 1.95 ANNUAL RUNOFF (INCHES) 45.07 40.49 26.49 10 PERCENT EXCEEDS 100 82 52 50 PERCENT EXCEEDS 21 18 13 90 PERCENT EXCEEDS 9.8 5.9 5.1 e Estimated 157 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR--Continued O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 158 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR. WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1969-76, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) NOV 03... 1105 44 291 8.0 24.9 40 8.0 98 11 26000 9500 FEB 14... 1200 26 344 8.1 24.2 4.2 8.5 102 <10 370 77 APR 19... 1400 9.4 363 8.0 26.8 3.5 7.7 98 <10 350 K150 AUG 24... 1040 22 329 7.6 26.1 6.5 7.6 95 11 35000 3500 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) NOV 03... 110 26.4 10.3 12.5 .5 3.9 96 <1.0 12.9 16.7 FEB 14... -- -- -- -- -- -- 115 -- -- -- APR 19... 130 32.8 11.9 19.1 .7 3.0 123 -- 12.0 27.1 AUG 24... 120 29.0 11.4 14.9 .6 3.9 92 -- 20.8 25.4 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 03... .1 26.3 167 19.7 55 1.27 .03 1.3 .10 .42 FEB 14... -- -- -- -- 7 2.38 .02 2.4 .05 .28 APR 19... .2 34.0 214 5.43 1 2.57 .03 2.6 .12 .34 AUG 24... .1 26.8 187 11.4 <10 2.18 .02 2.2 .18 .41 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) NOV 03... .52 1.8 8.1 .140 <3 53.5 24 .2 3 <20 FEB 14... .33 2.7 12.1 .180 -- -- -- -- -- -- APR 19... .46 3.1 13.5 .280 <3 46.5 25 <.1 <1 <20 AUG 24... .59 2.8 12.4 .190 -- -- -- -- -- -- 159 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR.--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 03... 1760 3 39 <.3 <3 <1 <31 <.01 9 .04 FEB 14... -- -- -- -- -- -- -- -- -- -- APR 19... 130 <1 22 <.3 <3 <1 <31 <.01 <4 .04 AUG 24... -- -- -- -- -- -- -- -- -- -- 160 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR LOCATION.--Lat 18°26'53", long 66°22'29", Hydrologic Unit 21010002, on left bank, at bridge on Hwy 2, 0.6 mi (1.0 km) downstream from Río Indio, and 0.8 mi (1.3 km) east of Vega Baja. DRAINAGE AREA.--99.1 mi2 (256.7 km2), of which 25.4 mi2 (65.8 km2), does not contribute directly to surface runoff. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1973 to current year. GAGE.--Water-stage recorder. Datum of gage is 7.79 ft (2.37 m) above mean sea level. REMARKS.--Records fair, except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. EXTREMES OUTSIDE PERIOD OF RECORD.--Flood of Dec. 11, 1965 reached a stage of 26.2 ft (7.99 m), datum unknown, discharge about 28,000 ft3/s (793 m3/s). DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e150 e300 1100 271 100 85 47 31 35 29 28 43 2 e140 e400 6860 250 94 79 46 32 34 28 44 50 3 e130 e240 4920 652 93 72 50 44 37 29 35 100 4 e120 e190 712 746 96 69 48 51 32 34 89 94 5 e110 226 1540 464 87 66 52 43 30 28 42 172 6 e105 349 1500 325 106 63 45 42 29 e26 30 59 7 e100 173 792 517 118 61 42 32 28 e26 27 46 8 e120 128 729 325 122 59 42 93 27 e27 28 45 9 e180 122 517 325 107 57 39 152 26 e27 25 201 10 e120 218 450 261 94 56 37 69 25 e27 28 111 11 e110 150 396 235 88 55 36 750 43 e27 46 58 12 e100 110 360 220 85 55 41 515 91 e28 27 44 13 e120 230 328 219 84 55 48 151 121 e28 25 40 14 e110 494 303 324 83 55 52 86 44 e29 25 37 15 e100 955 285 203 79 55 41 73 36 e28 29 36 16 e250 879 269 335 76 55 39 71 134 e27 26 40 17 e500 1710 279 205 92 81 40 191 152 e26 23 57 18 e200 1690 259 184 90 63 40 144 49 e26 21 325 19 165 1400 278 169 106 58 38 72 37 e27 22 232 20 767 788 255 159 87 54 40 64 34 e26 24 381 21 791 583 303 151 77 53 45 54 39 e26 22 172 22 714 505 385 147 146 61 44 48 34 e27 24 202 23 327 405 389 142 217 55 41 47 30 e27 544 249 24 372 363 334 133 245 54 36 47 28 28 246 161 25 668 302 354 127 281 54 33 46 28 27 163 124 26 457 321 341 119 143 51 32 47 44 27 143 75 27 212 312 261 111 161 58 31 43 80 27 112 67 28 e160 569 304 105 118 55 30 42 35 27 62 63 29 e140 680 523 142 88 69 30 39 31 38 48 52 30 e130 532 320 136 --- 51 31 41 29 30 41 48 31 e800 --- 272 107 --- 48 --- 41 --- 27 72 --- TOTAL 8468 15324 25918 7809 3363 1862 1216 3201 1422 864 2121 3384 MEAN 273 511 836 252 116 60.1 40.5 103 47.4 27.9 68.4 113 MAX 800 1710 6860 746 281 85 52 750 152 38 544 381 MIN 100 110 255 105 76 48 30 31 25 26 21 36 AC-FT 16800 30400 51410 15490 6670 3690 2410 6350 2820 1710 4210 6710 CFSM 2.76 5.15 8.44 2.54 1.17 .61 .41 1.04 .48 .28 .69 1.14 IN. 3.18 5.75 9.73 2.93 1.26 .70 .46 1.20 .53 .32 .80 1.27 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1973 - 2000, BY WATER YEAR (WY) MEAN 162 206 208 108 89.4 80.0 140 180 72.9 56.9 78.2 146 MAX 559 523 1316 339 190 339 667 655 239 235 461 690 (WY) 1986 1980 1982 1997 1988 1990 1987 1985 1987 1999 1979 1996 MIN 45.9 28.3 12.9 30.2 27.2 20.5 16.2 24.7 12.5 14.0 21.2 26.7 (WY) 1974 1998 1998 1995 1994 1994 1984 1977 1994 1994 1978 1994 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1973 - 2000 ANNUAL TOTAL 83732 74952 ANNUAL MEAN 229 205 126 HIGHEST ANNUAL MEAN 236 1982 LOWEST ANNUAL MEAN 38.5 1994 HIGHEST DAILY MEAN 6860 Dec 2 6860 Dec 2 14600 Dec 13 1981 LOWEST DAILY MEAN 30 Apr 21 21 Aug 18 7.2 May 3 1995 ANNUAL SEVEN-DAY MINIMUM 31 Apr 20 23 Aug 16 8.1 Apr 28 1995 INSTANTANEOUS PEAK FLOW 26400 Dec 2 34000 Apr 12 1987 INSTANTANEOUS PEAK STAGE 18.52 Dec 2 19.10 Apr 12 1987 INSTANTANEOUS LOW FLOW 19 Aug 22 7.2 May 2 1995 ANNUAL RUNOFF (AC-FT) 166100 148700 91390 ANNUAL RUNOFF (CFSM) 2.31 2.07 1.27 ANNUAL RUNOFF (INCHES) 31.43 28.14 17.30 10 PERCENT EXCEEDS 441 452 240 50 PERCENT EXCEEDS 117 80 58 90 PERCENT EXCEEDS 41 28 22 e Estimated 161 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 162 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR. WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) NOV 03... 1430 237 332 8.0 25.2 83 7.3 89 20 26000 31000 FEB 14... 1455 84 427 7.9 24.4 1.6 8.7 104 <10 300 33 APR 14... 1325 45 408 7.9 25.6 4.8 6.7 82 <10 330 320 AUG 17... 1300 24 468 7.7 29.1 .3 5.8 75 12 K8800 240 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) NOV 03... 140 44.6 6.71 10.1 .4 3.8 131 <1.0 11.3 14.3 FEB 14... -- -- -- -- -- -- 167 -- -- -- APR 14... 170 53.3 9.10 16.2 .5 2.5 162 <1.0 10.9 25.1 AUG 17... 190 59.8 8.80 17.5 .6 2.4 183 -- 11.6 26.8 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 03... <.1 15.8 185 119 188 1.07 .03 1.1 .06 .66 FEB 14... -- -- -- -- 5 1.58 .02 1.6 .09 -- APR 14... .2 20.6 235 28.3 9 1.86 .04 1.9 .22 .14 AUG 17... .1 17.7 254 16.4 <10 1.28 .02 1.3 .04 .17 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) NOV 03... .72 1.8 8.1 .230 <3 75.0 26 .2 10 20 FEB 14... <.20 -- -- .080 -- -- -- -- -- -- APR 14... .36 2.3 10.0 .150 <3 42.5 35 <.1 E1 <20 AUG 17... .21 1.5 6.7 .140 -- -- -- -- -- -- 163 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR.--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 03... 5130 5 263 <.3 <3 <1 E28 <.01 10 .09 FEB 14... -- -- -- -- -- -- -- -- -- -- APR 14... 270 <1 36 <.3 <3 <1 E26 <.01 <4 <.02 AUG 17... -- -- -- -- -- -- -- -- -- -- THIS PAGE IS INTENTIONALLY BLANK 164 18°27 30
 18°15
66°20
66°07 30
 Río Río Caño de Martín Peña Río Río Río Río Río Río Río de Río Río Lajas Río Río Río de de de la la la Plata Plata Plata Lago de la Plata Represa de Comerío Laguna San José Bahía de San Juan Bu ra ca nes bo Arroyata C u e s ta Arriba Cañas G u a d i a n a Hondo Usabón Aibonito Matón Guavate Lago Carite 0450 TUNNEL FLOW DIRECTION QUALITY-OF-WATER STATION AND NUMBER 216 1134 EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SEDIMENT STATION AND NUMBER SURFACE-WATER STATION AND NUMBER Figure 16. Río de la Plata basin. 045010 165 0460 0460 VEGA ALTA TOA ALTA DORADO TOA BAJA CATAÑO SAN JUAN ATLANTIC OCEAN AIBONITO BARRANQUITAS CAYEY COROZAL COMERÍO CIDRA NARANJITO AGUAS BUENAS 0 0 1 1 2 2 3 3 4 4 5 MILES Basin area PUERTO RICO 5 KILOMETERS 0460 0450 045010 044950 044850 0444 0438 0430 0399 039950 039990 0440 217 216 1133 1131, 1132 1126 1127 1129, 1130 1128 166 RIO DE LA PLATA BASIN 50039990 LAGO CARITE AT GATE TOWER NEAR CAYEY, PR LOCATION.--Lat 18°03'46", long 66°05'58", Hydrologic Unit 21010005, on top of a concrete tower at diversion tunnel on Carite Reservoir, 0.7 mi (1.1 km) northwest from Escuela Carite Chino, 1.2 mi (1.9 km) northeast from Central Hidroelectrica de Carite Num. 1 and 1.8 mi (2.9 km) northeast from Escuela Segunda Unidad. DRAINAGE AREA.--8.20 mi2 (21.24 km2). ELEVATION RECORDS PERIOD OF RECORD.--May 1989 to current year. Prior to October 1994, published as Lago Carite at Gate Tower. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Carite Dam was completed in 1913. The operation of the reservoir is controlled by the utilization of water to meet the demands for domestic, industrial and agricultural purposes in the Guayama Area. The dam is an earthfill with crest elevation of 1,806 ft (550 m) above mean sea level, with a structural height of 104 ft (32 m) and a lenght of 500 ft (152 m). The dam has a capacity of approximately 11,310 acre-feet (13.9 hm3). The Dam is operated by the Puerto Rico Electric and Power Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 1,789.62 ft (545.48 m), Sept. 21, 1998; minimum elevation, 1,761.22 ft (536.81 m), May 28, 1995. EXTREMES FOR CURRENT YEAR.--Maximum elevation 1,783.27 ft (543.54 m), Nov. 17; minimum elevation, 1,768.92 ft (539.17 m), Aug.22. Capacity Table (based on Data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 1,746 0 1,775 6,194 1,760 2,471 1,780 7,704 1,769 4,561 1,790 11,048 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1778.48 1778.81 1781.55 1781.52 1781.23 1780.08 1778.07 1775.69 1774.69 1773.03 1770.52 1773.47 2 1778.59 1778.83 1781.54 1781.48 1781.23 1780.03 1777.97 1775.60 1774.61 1773.00 1770.45 1773.42 3 1778.65 1778.87 1781.55 1781.51 1781.20 1779.98 1777.89 1775.50 1774.50 1772.93 1770.40 1773.36 4 1778.65 1778.83 1781.54 1781.50 1781.19 1779.93 1777.80 1775.41 1774.46 1772.83 1770.60 1773.29 5 1778.63 1778.84 1781.89 1781.72 1781.16 1779.88 1777.72 1775.31 1774.34 1772.76 1770.58 1773.24 6 1778.62 1778.96 1781.79 1781.72 1781.13 1779.81 1777.64 1775.21 1774.24 1772.67 1770.48 1773.23 7 1778.59 1778.95 1781.74 1781.66 1781.11 1779.76 1777.55 1775.10 1774.13 1772.58 1770.40 1773.16 8 1778.59 1778.94 1781.68 1781.60 1781.11 1779.71 1777.46 1775.00 1774.03 1772.49 1770.32 1773.09 9 1778.58 1779.00 1781.62 1781.54 1781.06 1779.65 1777.38 1774.89 1773.94 1772.41 1770.21 1773.02 10 1778.51 1780.29 1781.59 1781.51 1780.99 1779.59 1777.29 1774.78 1773.85 1772.33 1770.13 1773.04 11 1778.49 1780.53 1781.56 1781.49 1780.94 1779.52 1777.15 1774.85 1773.74 1772.19 1770.03 1773.60 12 1778.53 1781.96 1781.53 1781.44 1780.87 1779.47 1777.07 1774.75 1774.09 1772.13 1769.92 1773.56 13 1778.50 1782.58 1781.53 1781.43 1780.84 1779.40 1776.98 1774.66 1774.10 1772.06 1769.79 1773.50 14 1778.51 1782.01 1781.50 1781.44 1780.80 1779.36 1776.91 1774.56 1774.03 1772.06 1769.73 1773.43 15 1778.48 1781.84 1781.50 1781.53 1780.75 1779.29 1776.81 1774.44 1773.97 1771.96 1769.63 1773.35 16 1778.41 1781.97 1781.49 1781.49 1780.70 1779.24 1776.77 1774.34 1774.14 1771.86 1769.55 1773.31 17 1778.43 1783.04 1781.48 1781.45 1780.63 1779.20 1776.70 1774.55 1774.11 1771.82 1769.46 1774.54 18 1778.41 1782.56 1781.48 1781.45 1780.58 1779.12 1776.66 1775.10 1774.07 1771.71 1769.34 1775.57 19 1778.35 1782.32 1781.58 1781.41 1780.53 1779.05 1776.72 1775.22 1773.97 1771.66 1769.22 1775.68 20 1778.44 1782.09 1781.60 1781.39 1780.46 1778.95 1776.69 1775.15 1773.89 1771.55 1769.10 1775.70 21 1778.50 1781.91 1781.56 1781.37 1780.38 1778.86 1776.59 1775.10 1773.79 1771.44 1768.99 1775.73 22 1778.48 1781.82 1781.55 1781.37 1780.30 1778.78 1776.50 1775.00 1773.71 1771.34 1769.19 1775.72 23 1778.48 1781.74 1781.53 1781.33 1780.22 1778.68 1776.41 1774.91 1773.65 1771.24 1772.93 1775.71 24 1778.43 1781.70 1781.51 1781.32 1780.38 1778.62 1776.33 1774.81 1773.53 1771.12 1773.06 1775.67 25 1778.85 1781.67 1781.49 1781.33 1780.36 1778.53 1776.25 1774.75 1773.46 1771.04 1773.20 1775.65 26 1778.87 1781.63 1781.47 1781.33 1780.26 1778.45 1776.15 1774.63 1773.43 1770.91 1773.52 1775.60 27 1778.91 1781.62 1781.45 1781.30 1780.19 1778.37 1776.06 1774.56 1773.36 1770.80 1773.60 1775.92 28 1778.87 1781.60 1781.51 1781.29 1780.10 1778.38 1775.96 1774.50 1773.27 1770.68 1773.64 1776.22 29 1778.84 1781.59 1781.67 1781.29 1780.12 1778.32 1775.87 1774.48 1773.20 1770.77 1773.60 1776.26 30 1778.80 1781.56 1781.60 1781.26 --- 1778.24 1775.79 1774.82 1773.09 1770.72 1773.56 1776.26 31 1778.81 --- 1781.55 1781.23 --- 1778.16 --- 1774.77 --- 1770.62 1773.52 --- MAX 1778.91 1783.04 1781.89 1781.72 1781.23 1780.08 1778.07 1775.69 1774.69 1773.03 1773.64 1776.26 MIN 1778.35 1778.81 1781.45 1781.23 1780.10 1778.16 1775.79 1774.34 1773.09 1770.62 1768.99 1773.02 167 RIO DE LA PLATA BASIN 50039990 LAGO CARITE AT GATE TOWER NEAR CAYEY, PR--Continued O N D 1999 J F M A M J J A S 2000 1768 1770 1772 1774 1776 1778 1780 1782 1784 ELEVATION, IN FEET 168 RIO DE LA PLATA BASIN 50043000 RIO DE LA PLATA AT PROYECTO LA PLATA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18 09'37", long 66 13'44", Hydrologic Unit 21010005, at upstream side of bridge on Highway 173, 0.4 mi (0.6 km) northeast of Proyecto La Plata, and 2.5 mi (4.0 km) upstream from Río Usabón. DRAINAGE AREA.--63.0 mi2 (163.2 km2), excludes 8.2 mi2 (21.1 km2) upstream from Carite Reservoir, the flow of which is diverted to Río Guamaní. PERIOD OF RECORD.--Water years 1958 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) OCT 26... 1500 137 206 7.8 27.5 150 7.1 93 16 K7300 7400 FEB 11... 1030 39 468 8.3 23.0 1.4 8.8 106 <10 K640 K18 APR 17... 1030 24 487 8.1 24.8 2.8 8.0 100 11 410 270 AUG 14... 1135 7.4 510 7.9 28.7 3.7 7.2 96 13 570 K110 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) OCT 26... 79 19.7 7.23 14.8 .7 1.9 75 <1.0 9.0 12.6 FEB 11... -- -- -- -- -- -- 157 -- -- -- APR 17... 160 39.4 15.3 36.0 1 2.9 169 <1.0 19.0 44.7 AUG 14... 170 37.6 19.3 85.7 3 4.4 144 -- 22.0 59.9 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 26... .1 19.7 130 48.1 160 1.17 .03 1.2 .09 1.0 FEB 11... -- -- -- -- 7 1.75 .05 1.8 .03 .26 APR 17... .1 25.1 284 18.2 5 1.57 .03 1.6 .07 .32 AUG 14... .1 26.1 342 6.86 <10 2.26 .04 2.3 .04 .42 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 26... 1.1 2.3 10.2 .130 <3 33.8 26 <.1 1 <20 FEB 11... .29 2.1 9.3 .080 -- -- -- -- -- -- APR 17... .39 2.0 8.8 .130 <3 26.4 74 <.1 <1 <20 AUG 14... .46 2.8 12.2 .200 -- -- -- -- -- -- 169 RIO DE LA PLATA BASIN 50043000 RIO DE LA PLATA AT PROYECTO LA PLATA, PR WATER-QUALITY RECORDS MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 26... 3460 1 190 <.3 <3 <1 <31 <.01 <4 <.16 FEB 11... -- -- -- -- -- -- -- -- -- -- APR 17... 140 <1 17 <.3 <3 <1 <31 <.01 <4 .04 AUG 14... -- -- -- -- -- -- -- -- -- -- 170 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR LOCATION.--Lat 18°13'23", long 66°13'30", Hydrologic Unit 21010005, on right bank 50 ft (15 m) upstream from bridge off Highway 167 in the Town of Comerío, 0.4 mi (0.6 km) southwest of Comerío High School, and 0.2 mi (0.3 km) northeast of Plaza de Comerío. DRAINAGE AREA.--109 mi2 (282 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 604.2 ft (184.16 m) above mean sea level. REMARKS.--Records fair except those for estimated daily discharges, which are poo. Filtration plant more or less 500 feet upstream from station. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 92 262 177 192 80 74 40 29 73 32 39 70 2 314 869 229 159 78 70 39 33 54 41 54 64 3 72 634 407 480 73 60 38 31 45 48 38 57 4 44 210 188 610 71 57 38 33 44 50 39 293 5 35 141 901 460 71 57 39 38 40 45 137 172 6 29 230 1440 1020 67 54 36 32 36 42 70 76 7 29 156 666 956 66 53 35 28 34 38 34 84 8 38 102 683 385 72 51 30 25 35 37 28 69 9 60 80 410 257 66 49 30 27 29 36 25 66 10 44 976 323 188 63 48 31 29 27 33 24 50 11 48 503 242 158 63 51 32 56 26 27 23 135 12 41 e799 205 140 59 51 33 146 162 26 21 124 13 54 e1060 182 137 60 48 39 99 377 26 21 64 14 63 e752 168 136 65 48 42 46 77 39 21 50 15 120 655 153 140 66 49 44 33 46 44 26 50 16 489 1500 143 298 62 49 39 32 210 35 22 46 17 340 9880 146 143 58 46 40 38 255 34 19 104 18 148 8130 137 121 66 46 43 515 77 39 19 2550 19 94 4590 164 111 76 44 40 591 46 27 18 545 20 180 2070 339 105 85 40 67 302 37 28 18 419 21 503 1010 230 102 63 45 58 98 32 26 17 407 22 347 657 244 98 122 46 42 112 30 24 34 412 23 332 499 213 95 173 42 36 78 26 22 14000 279 24 265 412 198 91 143 41 31 55 25 22 795 167 25 952 364 169 89 294 41 e30 48 42 22 331 127 26 471 361 145 96 115 41 e29 48 33 22 554 91 27 141 268 129 89 86 41 28 43 77 21 487 250 28 92 261 128 81 73 41 27 40 55 21 203 270 29 73 264 1200 83 67 41 26 53 36 22 141 270 30 60 212 393 90 --- 43 29 182 30 29 100 137 31 359 --- 239 78 --- 44 --- 190 --- 29 81 --- TOTAL 5929 37907 10591 7188 2503 1511 1111 3110 2116 987 17439 7498 MEAN 191 1264 342 232 86.3 48.7 37.0 100 70.5 31.8 563 250 MAX 952 9880 1440 1020 294 74 67 591 377 50 14000 2550 MIN 29 80 128 78 58 40 26 25 25 21 17 46 MED 92 501 213 137 71 48 37 46 41 29 34 126 AC-FT 11760 75190 21010 14260 4960 3000 2200 6170 4200 1960 34590 14870 CFSM 1.76 11.6 3.15 2.14 .80 .45 .34 .92 .65 .29 5.18 2.30 IN. 2.03 13.00 3.63 2.46 .86 .52 .38 1.07 .73 .34 5.98 2.57 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 2000, BY WATER YEAR (WY) MEAN 227 218 116 144 96.8 44.5 52.0 87.1 72.4 86.7 132 444 MAX 866 1264 457 732 268 75.7 162 263 213 291 563 1433 (WY) 1991 2000 1999 1992 1998 1989 1993 1992 1996 1993 2000 1996 MIN 40.6 19.0 17.1 21.3 24.4 20.6 22.3 19.7 13.2 10.4 12.7 26.2 (WY) 1992 1995 1995 1995 1990 1993 1991 1994 1994 1994 1994 1997 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1989 - 2000 ANNUAL TOTAL 82007 97890 ANNUAL MEAN 225 267 142 HIGHEST ANNUAL MEAN 267 2000 LOWEST ANNUAL MEAN 35.3 1994 HIGHEST DAILY MEAN 9880 Nov 17 14000 Aug 23 32400 Sep 10 1996 LOWEST DAILY MEAN 17 Jun 26 17 Aug 21 5.8 Jun 25 1994 ANNUAL SEVEN-DAY MINIMUM 20 Jun 23 20 Aug 15 7.3 Jul 31 1994 INSTANTANEOUS PEAK FLOW 49000 Aug 23 127000 Jan 5 1992 INSTANTANEOUS PEAK STAGE 20.03 Aug 23 29.22 Jan 5 1992 ANNUAL RUNOFF (AC-FT) 162700 194200 103000 ANNUAL RUNOFF (CFSM) 2.07 2.47 1.31 ANNUAL RUNOFF (INCHES) 28.12 33.56 17.81 10 PERCENT EXCEEDS 411 474 198 50 PERCENT EXCEEDS 73 66 40 90 PERCENT EXCEEDS 31 28 16 e Estimated 171 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 10,000 20,000 50,000 100,000 DISCHARGE, IN CUBIC FEET PER SECOND 172 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water year 1989 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1989 to current year. INSTRUMENTATION.-- USD-77 sediment sampler since 1989. Automatic sediment sampler since 1989. REMARKS.--Sediment samples were collected by a local observer on a week basis. During high flow events sediment samples were collected by hydrologic technician and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 8,800 mg/L January 05, 1992; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 950,000 tons (862,000 tonnes) January 05, 1992; Minimum daily mean, 0.04 tons (0.04 tonne) November 28, 1994. EXTREMES FOR WATER YEARS 2000.-- SEDIMENT CONCENTRATION: Maximun daily mean, 2,210 mg/L September 18, 2000; Minimun daily mean, 5 mg/L November 24, 1999. SEDIMENT LOADS: Maximun daily mean, 48,500 tons (44,000 tonnes) November 17, 1999; Minimun daily mean, 0.51 ton (0.46 tonne) April 10, 2000. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 92 42 25 262 240 189 177 6 2.8 2 314 183 188 869 378 2480 229 30 32 3 72 54 11 634 291 647 407 66 94 4 44 37 4.4 210 183 102 188 15 7.8 5 35 33 3.1 141 227 89 901 232 1370 6 29 29 2.2 230 208 137 1440 103 662 7 29 26 2.0 156 183 77 666 6 12 8 38 30 3.1 102 180 49 683 7 13 9 60 49 8.8 80 95 21 410 7 7.2 10 44 36 4.4 976 811 3290 323 6 5.3 11 48 35 4.6 503 1080 1570 242 6 4.1 12 41 31 3.4 e799 e754 e2560 205 7 3.6 13 54 43 6.5 e1060 e588 e2250 182 8 3.7 14 63 51 9.1 e752 e694 e1730 168 22 9.9 15 120 82 70 655 384 695 153 69 29 16 489 250 819 1500 558 2510 143 75 29 17 340 222 252 9880 1430 48500 146 61 24 18 148 99 42 8130 585 13800 137 51 19 19 94 63 16 4590 188 2430 164 43 19 20 180 124 86 2070 63 375 339 38 35 21 503 238 324 1010 21 60 230 49 30 22 347 181 192 657 7 13 244 64 42 23 332 212 206 499 6 7.5 213 57 33 24 265 176 136 412 5 5.8 198 47 25 25 952 402 2390 364 6 6.2 169 51 23 26 471 286 446 361 8 7.8 145 62 24 27 141 116 44 268 10 7.5 129 72 25 28 92 107 27 261 13 9.4 128 77 27 29 73 104 21 264 15 11 1200 521 2220 30 60 75 12 212 10 5.7 393 225 255 31 359 198 547 --- --- --- 239 76 50 TOTAL 5929 --- 5905.6 37907 --- 83634.9 10591 --- 5136.4 173 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 192 58 30 80 36 7.8 74 16 3.3 2 159 53 23 78 37 7.8 70 12 2.3 3 480 128 314 73 39 7.8 60 8 1.4 4 610 351 614 71 42 8.0 57 8 1.2 5 460 213 288 71 45 8.6 57 8 1.2 6 1020 376 1720 67 49 8.9 54 8 1.2 7 956 231 853 66 53 9.3 53 8 1.2 8 385 75 78 72 49 9.6 51 9 1.2 9 257 64 45 66 45 8.0 49 10 1.3 10 188 57 29 63 43 7.4 48 11 1.5 11 158 71 30 63 52 8.8 51 16 2.2 12 140 92 35 59 64 10 51 23 3.1 13 137 84 31 60 52 8.4 48 28 3.6 14 136 74 27 65 43 7.6 48 19 2.4 15 140 91 37 66 46 8.2 49 12 1.7 16 298 183 156 62 52 8.7 49 11 1.5 17 143 79 31 58 58 9.0 46 11 1.4 18 121 55 18 66 64 11 46 13 1.6 19 111 48 14 76 71 15 44 16 1.9 20 105 54 15 85 83 19 40 18 2.0 21 102 60 16 63 107 18 45 15 1.8 22 98 52 14 122 136 59 46 12 1.4 23 95 41 10 173 168 101 42 11 1.2 24 91 33 8.0 143 98 43 41 10 1.1 25 89 35 8.4 294 164 138 41 9 1.0 26 96 39 10 115 81 26 41 9 .94 27 89 37 8.9 86 40 9.3 41 8 .91 28 81 34 7.4 73 17 3.3 41 9 .94 29 83 34 7.5 67 15 2.8 41 9 .97 30 90 34 8.3 --- --- --- 43 9 .98 31 78 35 7.4 --- --- --- 44 8 .94 TOTAL 7188 --- 4493.9 2503 --- 589.3 1511 --- 49.38 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 40 7 .80 29 132 10 73 71 14 2 39 7 .70 33 123 11 54 56 8.2 3 38 6 .65 31 114 9.6 45 46 5.6 4 38 9 .88 33 110 9.7 44 37 4.4 5 39 11 1.2 38 108 11 40 30 3.2 6 36 9 .91 32 105 9.1 36 21 2.0 7 35 7 .68 28 103 7.9 34 14 1.3 8 30 7 .55 25 100 6.8 35 13 1.2 9 30 6 .51 27 92 6.8 29 14 1.1 10 31 6 .51 29 85 6.5 27 22 1.6 11 32 6 .52 56 88 14 26 22 1.6 12 33 6 .54 146 98 39 162 89 90 13 39 6 .63 99 97 26 377 210 297 14 42 6 .68 46 104 13 77 22 5.1 15 44 7 .77 33 97 8.8 46 18 2.2 16 39 7 .76 32 72 6.2 210 104 134 17 40 8 .91 38 50 5.1 255 154 123 18 43 13 1.5 515 250 1310 77 48 11 19 40 18 2.0 591 545 1020 46 20 2.5 20 67 12 2.1 302 270 242 37 14 1.5 21 58 7 1.2 98 99 28 32 13 1.1 22 42 18 1.9 112 99 32 30 16 1.3 23 36 53 5.0 78 73 15 26 21 1.4 24 31 129 11 55 57 8.5 25 22 1.5 25 e30 e142 e11 48 87 11 42 34 4.0 26 e29 e137 e11 48 131 17 33 20 1.8 27 28 101 7.8 43 125 15 77 50 12 28 27 103 7.6 40 109 12 55 18 2.9 29 26 113 7.9 53 104 15 36 12 1.1 30 29 124 9.6 182 143 111 30 12 .94 31 --- --- --- 190 124 72 --- --- --- TOTAL 1111 --- 91.80 3110 --- 3109.0 2116 --- 738.54 174 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 32 16 1.4 39 36 4.0 70 49 9.3 2 41 23 2.6 54 45 6.5 64 45 7.9 3 48 31 4.0 38 37 3.8 57 42 6.5 4 50 21 2.9 39 32 3.6 293 151 418 5 45 15 1.8 137 90 34 172 126 67 6 42 20 2.2 70 75 14 76 55 11 7 38 27 2.8 34 52 4.8 84 68 15 8 37 28 2.8 28 52 4.0 69 60 11 9 36 28 2.7 25 54 3.6 66 51 9.0 10 33 27 2.5 24 35 2.3 50 42 5.7 11 27 27 2.0 23 22 1.3 135 82 48 12 26 27 1.9 21 22 1.2 124 89 32 13 26 24 1.7 21 24 1.4 64 48 8.4 14 39 35 3.9 21 26 1.5 50 39 5.3 15 44 37 4.4 26 25 1.8 50 35 4.7 16 35 29 2.7 22 23 1.4 46 35 4.4 17 34 26 2.5 19 22 1.1 104 80 32 18 39 17 1.9 19 20 1.1 2550 2220 24500 19 27 10 .77 18 22 1.0 545 307 481 20 28 11 .82 18 24 1.2 419 203 262 21 26 12 .82 17 26 1.2 407 168 445 22 24 12 .77 34 52 8.1 412 293 351 23 22 13 .76 14000 712 40500 279 180 140 24 22 13 .78 795 129 280 167 118 53 25 22 14 .85 331 109 98 127 97 34 26 22 15 .85 554 297 510 91 80 20 27 21 15 .86 487 315 474 250 152 166 28 21 16 .90 203 130 72 270 170 129 29 22 17 1.0 141 90 35 270 152 115 30 29 21 1.7 100 68 19 137 95 36 31 29 28 2.2 81 56 12 --- --- --- TOTAL 987 --- 59.78 17439 --- 42102.9 7498 --- 27427.2 YEAR 97890 173338.70 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- SEDI- SED. CHARGE, MENT, SUSP. INST. SEDI- DIS- SIEVE CUBIC MENT, CHARGE, DIAM. FEET SUS- SUS- % FINER DATE TIME PER PENDED PENDED THAN SECOND (MG/L) (T/DAY) .062 MM (00061) (80154) (80155) (70331) NOV 12... 1550 1310 1710 6070 98 17... 1355 9580 1300 33600 95 17... 2100 9090 876 21500 98 JAN 28... 1650 81 33 7.2 88 FEB 16... 1130 64 52 9.0 90 MAR 13... 0940 52 31 4.4 57 JUL 03... 1230 54 34 5.0 74 AUG 23... 0910 31100 901 75700 97 SEP 18... 0840 3140 1480 12500 93 175 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) OCT 25... 2210 1760 862 4100 67 79 93 NOV 17... 1700 9650 1040 27200 50 61 72 AUG 23... 0410 17600 1940 92000 32 41 50 SEP 18... 0225 4660 2740 34500 44 56 70 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) OCT 25... 98 99 99 100 100 100 100 NOV 17... 84 92 94 98 99 100 100 AUG 23... 59 68 73 86 97 99 100 SEP 18... 83 92 96 98 99 100 100 176 RIO DE LA PLATA BASIN 50044000 RIO DE LA PLATA NEAR COMERIO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°14'33", long 66°12'28", at bridge on Highway 156, 0.56 mi (0.9 km) upstream from dam, about 2.0 mi (3.2 km) northeast of Comerío plaza. DRAINAGE AREA.--139 mi2 (360 km2), excludes 8.2 mi2 (21.1 km2) upstream from Carite Reservoir, the flow of which is diverted to Río Guamaní. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) NOV 18... 1310 E1000 187 7.8 23.7 140 8.2 101 26 K7200 8500 FEB 08... 0820 122 480 8.2 21.0 2.4 8.2 94 <10 K100 58 MAY 01... 1400 46 417 8.3 28.5 1.9 8.2 109 <10 K120 K120 SEP 06... 1030 74 363 7.8 28.3 17 7.5 98 12 3100 300 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) NOV 18... 110 29.5 8.40 38.2 2 4.0 61 <1.0 18.2 67.4 FEB 08... -- -- -- -- -- -- 162 -- -- -- MAY 01... 170 38.1 18.5 22.0 .7 1.4 153 <1.0 14.3 27.3 SEP 06... 130 31.3 12.9 21.2 .8 3.0 115 -- 14.6 23.5 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 18... <.1 7.3 209 -- 188 .93 .03 1.0 .08 1.3 FEB 08... -- -- -- -- 2 1.49 .01 1.5 .03 .20 MAY 01... <.1 41.9 255 31.4 2 .35 .01 .4 .14 -- SEP 06... .1 25.8 201 40.4 22 .97 .01 1.0 .05 .23 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) NOV 18... 1.4 2.4 10.4 .250 E1 34.3 27 .1 6 E15 FEB 08... .23 1.7 7.7 .060 -- -- -- -- -- -- MAY 01... <.20 -- -- .050 <3 20.0 36 <.1 <1 <20 SEP 06... .28 1.3 5.6 .110 -- -- -- -- -- -- 177 RIO DE LA PLATA BASIN 50044000 RIO DE LA PLATA NEAR COMERIO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 18... 4750 2 175 <.3 <3 <1 <31 <.01 5 <.04 FEB 08... -- -- -- -- -- -- -- -- -- -- MAY 01... 70 <1 14 <.3 <3 <1 <31 <.01 7 <.02 SEP 06... -- -- -- -- -- -- -- -- -- -- 178 RIO DE LA PLATA BASIN 50044850 RIO GUADIANA NEAR NARANJITO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°18'39", long 66°13'28", at steel-cross-bridge 0.8 mi (1.3 km) northwest of Highway 164, 1.2 mi (1.9 km) upstream from mouth and about 2.0 mi (3.2 km) northeast of Naranjito plaza. DRAINAGE AREA.--4.0 mi2 (10.3 km2). PERIOD OF RECORD.--Water year 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, NESS CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR TOTAL FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. (MG/L DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER AS SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) OCT 17... 1340 14 366 7.9 28.8 17 6.1 80 <10 K10000 K1100 150 FEB 08... 1030 18 339 8.1 23.0 1.4 8.0 94 <10 K100 41 -- MAY 01... 1235 5.9 365 7.9 29.5 .4 6.7 93 <10 290 K100 140 SEP 06... 0800 6.4 382 7.4 26.9 .3 5.5 70 <10 K1100 480 140 ANC SOLIDS, MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- DATE (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) OCT 17... 33.5 15.0 16.5 .6 2.6 130 -- 23.8 21.8 .1 27.7 219 FEB 08... -- -- -- -- -- 119 -- -- -- -- -- -- MAY 01... 31.5 14.2 17.0 .6 2.1 130 <1.0 14.5 26.0 <.1 29.5 213 SEP 06... 34.4 14.0 17.9 .6 2.3 128 -- 21.6 23.3 <.1 26.0 216 RESIDUE NITRO- SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM DIS- AT 105 GEN, GEN, GEN, GEN, MONIA + PHOS- TOTAL TOTAL WATER SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC PHORUS ARSENIC RECOV- RECOV- UNFLTRD (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS P) AS AS) AS BA) AS B) AS CD) (70302) (00530) (00620) (00615) (00630) (00610) (00625) (00665) (01002) (01007) (01022) (01027) OCT 17... 8.11 24 -- -- -- -- -- -- E2 62.7 23 <.1 FEB 08... -- 2 -- <.01 1.6 .02 <.20 .100 -- -- -- -- MAY 01... 3.36 <1 1.69 .01 1.7 .04 <.20 .190 <3 46.5 36 <.1 SEP 06... 3.77 <10 -- <.01 1.1 .03 <.20 .150 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 17... 3 <20 1070 E1 96 <.3 <3 <1 <31 <.01 -- -- FEB 08... -- -- -- -- -- -- -- -- -- -- -- -- MAY 01... <1 <20 50 <1 20 <.3 <3 <1 <31 <.01 5 <.02 SEP 06... -- -- -- -- -- -- -- -- -- -- -- -- 179 RIO DE LA PLATA BASIN 50045000 LAGO LA PLATA AT DAMSITE NEAR TOA ALTA, PR LOCATION.--Lat 18°20'40", long 66°14'10", Hydrologic Unit 21010005, 2.9 mi (4.7 km) at northeast of Plaza de Naranjito, 2.7 mi (4.3 km) West of Road 167, km 15.3, Buena Vista, Bayamón, 5.2 mi (8.4 km) east of Plaza de Corozal. DRAINAGE AREA.--181 mi2 (469 km2). ELEVATION RECORDS PERIOD OF RECORD.--February 1989 to current year. Prior to October 1994, published as Lago La Plata at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago La Plata first construction phase was completed in 1974 and the second construction phase to provide the spillway with bascule gates was completed in October 1989. The maximum storage is 37,000 ac-ft (45.6 hm3) and its purpose is the supply of water for domestic and industrial use. La Plata Dam is a concrete gravity structure located across the Rio de la Plata, the dam has an overall length of 774 ft (236 m) and a maximum height of about 131 ft (40 m). The dam spillway is provided with 6 bascule gates. The spillway crest has a total clear length of 690 ft (210 m), an elevation of 155 ft (47 m). The Dam is owned and operated by Puerto Rico Aqueduct and Sewer Authority. Gage-height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 00-40-45, October 1998. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 170.90 ft (52.09 m), Sept. 10, 1996; minimum elevation, 107.95 ft (32.90 m), Feb. 21, 1995. EXTREMES FOR CURRENT YEAR.--Maximum elevation, 166.24 ft (50.67 m), Dec. 29; minimum elevation, 139.24 ft (42.44 m), Aug. 22. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 00-4045,Puerto Rico-1998) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 82 0 144 12,915 105 1,873 164 24,021 125 5,943 171 28,748 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 164.13 164.05 164.77 164.57 164.53 164.71 162.44 157.75 157.05 153.91 145.83 164.33 2 164.36 164.33 164.73 164.45 164.71 164.72 162.30 157.55 156.91 153.65 145.64 164.35 3 163.84 164.32 164.10 164.33 164.83 164.71 162.18 157.36 156.71 153.41 145.54 164.34 4 163.93 164.11 164.35 164.15 164.70 164.68 162.03 157.18 156.52 153.18 145.27 164.56 5 163.97 164.12 164.16 164.75 164.17 164.68 161.90 157.04 156.29 153.02 145.20 164.93 6 164.21 163.95 164.14 164.61 164.24 164.63 161.75 156.87 156.06 152.86 145.02 164.76 7 164.22 164.24 164.41 164.18 164.33 164.58 161.60 156.68 155.80 152.69 144.75 164.85 8 164.28 164.37 164.17 164.87 164.41 164.52 161.44 156.49 155.54 152.50 144.38 164.68 9 164.34 163.81 164.87 164.62 164.45 164.45 161.26 156.28 155.28 152.32 144.00 164.68 10 164.05 163.86 164.77 164.01 164.50 164.37 161.11 156.05 154.99 152.13 143.62 164.66 11 163.92 164.01 164.49 164.33 164.53 164.30 160.93 156.61 154.76 151.93 143.21 164.72 12 164.09 164.00 164.02 164.73 164.56 164.23 160.80 156.78 154.97 151.73 142.80 164.91 13 163.80 163.98 164.57 164.39 164.59 164.15 160.68 156.78 155.70 151.54 142.40 164.93 14 163.85 163.93 164.09 164.88 164.63 164.07 160.56 156.64 155.66 151.34 142.00 164.91 15 163.88 163.34 164.57 164.65 164.67 164.00 160.42 156.45 155.52 151.18 141.65 164.89 16 164.22 161.75 164.07 164.50 164.69 163.96 160.27 156.22 156.29 150.91 141.36 164.85 17 164.13 162.88 164.54 164.63 164.62 163.88 160.12 156.03 156.84 150.62 140.99 162.77 18 163.82 163.57 164.41 164.31 164.72 163.80 159.97 156.25 156.79 150.36 140.61 163.39 19 163.33 163.48 164.30 164.59 164.80 163.68 159.82 157.53 156.59 150.05 140.25 163.58 20 162.21 163.68 164.38 164.85 164.15 163.58 159.76 158.10 156.37 149.75 139.88 163.40 21 162.46 164.32 164.58 164.31 164.21 163.48 159.68 158.08 156.14 149.45 139.47 163.91 22 163.71 164.23 164.38 164.55 164.64 163.41 159.53 158.02 155.89 149.14 139.25 163.88 23 164.49 163.88 164.13 164.78 164.28 163.29 159.37 157.93 155.62 148.80 163.95 163.58 24 163.87 163.88 164.54 164.83 164.21 163.17 159.19 157.80 155.33 148.46 164.57 163.88 25 163.81 164.50 164.54 164.26 164.24 163.05 158.98 157.65 155.13 148.13 164.46 163.69 26 164.14 165.16 164.05 164.45 164.50 162.95 158.79 157.46 155.05 147.78 164.68 163.55 27 164.01 164.10 164.45 164.62 164.62 162.92 158.58 157.26 154.89 147.42 164.83 163.86 28 164.16 164.13 164.16 164.75 164.67 162.84 158.35 157.06 154.70 147.09 165.03 163.58 29 164.23 164.88 164.24 164.08 164.69 162.78 158.13 156.87 154.46 146.77 164.43 163.93 30 164.25 164.16 164.61 164.25 --- 162.68 157.92 156.88 154.19 146.44 164.46 163.60 31 164.50 --- 164.34 164.39 --- 162.57 --- 157.16 --- 146.09 164.37 --- MAX 164.50 165.16 164.87 164.88 164.83 164.72 162.44 158.10 157.05 153.91 165.03 164.93 MIN 162.21 161.75 164.02 164.01 164.15 162.57 157.92 156.03 154.19 146.09 139.25 162.77 180 RIO DE LA PLATA BASIN 50045000 LAGO LA PLATA AT DAMSITE NEAR TOA ALTA, PR--Continued O N D 1999 J F M A M J J A S 2000 135 140 145 150 155 160 165 170 ELEVATION, IN FEET 181 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM LOCATION.--Lat 18°20'45", long 66°14'17", Hydrologic Unit 21010005, 2.8 mi (4.5 km) west of Road 167, km 15.3, Buena Vista, Bayamón, 5.0 mi (8.0 km) east of Corozal Plaza, 3.0 mi (4.8 km) northeast of Naranjito Plaza . DRAINAGE AREA.--173 mi2 (448 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--July 1989 to current year. GAGE.--Water-stage recorder. Elevation of gage 66 ft (20 m), from topographic map. REMARKS.--Records poor. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 110 449 179 69 3.1 2.2 .93 .13 .93 .96 1.1 3.2 2 254 395 4470 294 1.7 2.4 1.0 .15 2.2 .96 .15 1.1 3 294 602 1500 825 1.5 2.6 1.0 .14 1.6 1.1 1.1 2.1 4 4.0 279 258 1100 75 2.5 1.3 .33 .41 1.1 2.1 1.9 5 2.5 148 2790 255 264 2.6 1.4 .68 .14 2.1 1.7 1.2 6 3.1 321 2020 973 1.2 2.5 1.3 .49 .09 2.5 1.6 1.6 7 2.7 4.8 815 1330 1.2 2.4 1.3 .29 .21 .97 1.5 .00 8 2.4 4.1 1050 217 1.4 2.3 1.1 .31 .10 .57 1.5 84 9 2.2 246 291 376 9.2 2.5 .82 .13 .05 .90 1.5 4.1 10 206 832 413 443 1.7 2.3 .76 .08 .03 .76 .95 3.2 11 129 420 401 59 1.7 2.2 .78 3.8 .12 .68 .40 2.3 12 139 524 433 3.3 1.8 2.2 .83 1.5 1.1 .64 .59 2.4 13 201 693 37 369 1.8 1.9 .87 .84 4.8 .59 1.3 2.4 14 8.6 835 374 3.5 2.1 1.9 .94 .67 3.4 .71 1.1 2.1 15 7.9 1100 4.5 357 2.7 2.1 .50 .41 1.7 1.0 1.4 2.2 16 287 1750 335 449 2.7 2.3 .36 2.2 3.3 .94 2.3 1.1 17 483 9930 5.4 116 35 2.4 .38 5.2 6.7 .91 1.1 9.9 18 306 9280 183 291 2.5 2.3 .65 5.7 5.3 .87 1.8 1530 19 404 4820 270 2.8 2.8 2.1 .27 9.6 15 1.1 2.7 480 20 1020 2020 226 2.9 301 2.1 .24 13 13 1.2 1.3 577 21 1180 723 135 310 2.3 1.9 .23 10 7.4 .92 2.7 37 22 63 792 424 2.3 3.1 2.2 .12 8.1 8.3 1.5 4.1 5.9 23 5.8 781 355 2.1 313 2.1 .10 6.3 7.2 1.2 8370 334 24 495 650 225 53 198 2.1 .24 5.6 4.5 1.8 507 1.8 25 768 182 372 325 382 2.0 .47 4.7 1.7 1.5 290 143 26 332 116 317 3.7 2.8 1.7 .36 3.8 .32 1.1 203 124 27 186 728 5.1 3.6 2.3 1.5 .13 1.8 3.9 1.1 317 2.1 28 2.9 1190 284 3.8 2.1 1.3 .07 5.3 19 1.2 3.4 298 29 2.6 254 1440 363 2.2 .98 .07 1.9 4.2 1.6 250 2.8 30 2.5 957 349 9.0 --- .87 .07 .87 1.8 2.2 2.1 3.3 31 7.5 --- 392 2.9 --- .75 --- .57 --- 1.5 2.7 --- TOTAL 6911.7 41025.9 20353.0 8613.9 1621.9 63.20 18.59 94.59 118.50 36.18 9979.19 3663.70 MEAN 223 1368 657 278 55.9 2.04 .62 3.05 3.95 1.17 322 122 MAX 1180 9930 4470 1330 382 2.6 1.4 13 19 2.5 8370 1530 MIN 2.2 4.1 4.5 2.1 1.2 .75 .07 .08 .03 .57 .15 .00 AC-FT 13710 81370 40370 17090 3220 125 37 188 235 72 19790 7270 CFSM 1.29 7.91 3.80 1.61 .32 .01 .00 .02 .02 .01 1.86 .71 IN. 1.49 8.83 4.38 1.85 .35 .01 .00 .02 .03 .01 2.15 .79 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 2000, BY WATER YEAR (WY) MEAN 191 205 173 215 55.8 13.3 25.8 89.9 33.5 66.4 63.1 962 MAX 1107 1368 926 1581 241 83.2 231 494 220 384 322 8046 (WY) 1991 2000 1999 1992 1998 1990 1993 1993 1993 1993 2000 1996 MIN .048 .004 .000 .19 .14 .022 .011 .000 .002 .037 .020 .001 (WY) 1992 1995 1995 1990 1995 1995 1995 1994 1994 1994 1989 1991 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1989 - 2000 ANNUAL TOTAL 87744.96 92500.35 ANNUAL MEAN 240 253 179 HIGHEST ANNUAL MEAN 714 1996 LOWEST ANNUAL MEAN 8.62 1997 HIGHEST DAILY MEAN 9930 Nov 17 9930 Nov 17 141000 Sep 10 1996 LOWEST DAILY MEAN .03 May 24 .00 Sep 7 .00 Jul 14 1989 ANNUAL SEVEN-DAY MINIMUM .04 May 18 .11 Jun 5 .00 Jul 14 1989 INSTANTANEOUS PEAK FLOW 39800 Aug 23 197000 Sep 10 1996 INSTANTANEOUS PEAK STAGE 21.34 Aug 23 42.26 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 174000 183500 129600 ANNUAL RUNOFF (CFSM) 1.39 1.46 1.04 ANNUAL RUNOFF (INCHES) 18.89 19.91 14.06 10 PERCENT EXCEEDS 529 499 206 50 PERCENT EXCEEDS 1.5 2.7 1.4 90 PERCENT EXCEEDS .15 .50 .00 182 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM--Continued O N D 1999 J F M A M J J A S 2000 0.01 0.02 0.05 0.1 0.1 0.2 0.5 1 2 5 10 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 183 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.--Water years 1990 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1989 to current year. INSTRUMENTATION.--Automatic sediment sampler since 1989. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean,4,390 mg/L September 10, 1996; Minimum daily mean, <1 mg/L several days. SEDIMENT LOADS: Maximum daily mean,1,810,000 tons (1,640,000 tonnes) September 10, 1996; Minimum daily mean, <0.01 ton (<0.01 tonne) several days. EXTREMES FOR CURRENT YEAR 2000.-- SEDIMENT CONCENTRATION: Maximum daily mean, 702 mg/L August 23, 2000; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 24,700 tons (22,400 tonnes) August 23, 2000; Minimum daily mean, <0.01 ton (<0.01 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 110 30 47 449 34 86 179 75 72 2 254 50 70 395 29 106 4470 233 3350 3 294 32 66 602 33 98 1500 249 1020 4 4.0 17 .19 279 31 54 258 77 170 5 2.5 16 .11 148 27 38 2790 202 1510 6 3.1 14 .12 321 37 46 2020 151 1000 7 2.7 13 .10 4.8 16 .21 815 134 387 8 2.4 12 .08 4.1 14 .15 1050 165 471 9 2.2 11 .07 246 34 45 291 69 93 10 206 31 52 832 46 187 413 71 188 11 129 36 23 420 36 49 401 74 166 12 139 39 35 524 40 136 433 82 181 13 201 47 44 693 92 172 37 46 6.8 14 8.6 18 .41 835 82 186 374 66 138 15 7.9 17 .37 1100 74 219 4.5 40 .49 16 287 34 73 1750 67 313 335 59 126 17 483 40 83 9930 67 1820 5.4 36 .51 18 306 32 61 9280 282 5920 183 45 67 19 404 31 74 4820 248 3380 270 55 57 20 1020 31 107 2020 91 528 226 43 74 21 1180 45 231 723 43 99 135 41 33 22 63 19 4.6 792 304 648 424 53 114 23 5.8 15 .24 781 274 571 355 45 85 24 495 34 98 650 103 410 225 37 46 25 768 34 180 182 57 62 372 47 59 26 332 29 54 116 56 85 317 31 51 27 186 25 31 728 260 507 5.1 35 .52 28 2.9 15 .12 1190 205 618 284 21 32 29 2.6 13 .09 254 80 95 1440 32 150 30 2.5 11 .07 957 220 564 349 26 32 31 7.5 10 .88 --- --- --- 392 25 46 TOTAL 6911.7 --- 1336.45 41025.9 --- 17042.36 20353.0 --- 9726.32 184 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 69 14 9.2 3.1 18 .15 2.2 7 .04 2 294 24 31 1.7 15 .07 2.4 7 .05 3 825 29 101 1.5 13 .05 2.6 6 .05 4 1100 39 116 75 14 10 2.5 6 .04 5 255 22 23 264 29 28 2.6 6 .04 6 973 29 138 1.2 19 .06 2.5 5 .04 7 1330 55 196 1.2 13 .04 2.4 5 .03 8 217 31 25 1.4 10 .04 2.3 5 .03 9 376 31 57 9.2 14 .68 2.5 4 .03 10 443 29 64 1.7 5 .02 2.3 4 .03 11 59 26 6.2 1.7 1 .01 2.2 4 .02 12 3.3 16 .15 1.8 2 .01 2.2 4 .02 13 369 25 54 1.8 2 .01 1.9 3 .02 14 3.5 17 .16 2.1 3 .02 1.9 3 .02 15 357 30 50 2.7 5 .04 2.1 3 .02 16 449 33 66 2.7 7 .05 2.3 3 .02 17 116 18 17 35 17 4.4 2.4 3 .02 18 291 29 32 2.5 19 .13 2.3 2 .01 19 2.8 18 .14 2.8 14 .10 2.1 2 .01 20 2.9 13 .10 301 10 8.6 2.1 2 .01 21 310 27 42 2.3 10 .06 1.9 2 .01 22 2.3 19 .12 3.1 10 .09 2.2 2 .01 23 2.1 12 .07 313 13 15 2.1 2 .01 24 53 11 9.8 198 17 9.0 2.1 2 .01 25 325 40 50 382 14 16 2.0 2 .01 26 3.7 21 .21 2.8 10 .07 1.7 1 .01 27 3.6 17 .17 2.3 9 .05 1.5 1 <.01 28 3.8 14 .14 2.1 8 .05 1.3 1 <.01 29 363 31 58 2.2 8 .05 .98 1 <.01 30 9.0 25 .56 --- --- --- .87 1 <.01 31 2.9 21 .17 --- --- --- .75 1 <.01 TOTAL 8613.9 --- 1147.19 1621.9 --- 92.85 63.20 --- 0.66 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 .93 1 <.01 .13 2 <.01 .93 2 <.01 2 1.0 1 <.01 .15 2 <.01 2.2 1 .01 3 1.0 1 <.01 .14 2 <.01 1.6 1 .01 4 1.3 1 <.01 .33 2 <.01 .41 1 <.01 5 1.4 1 <.01 .68 2 <.01 .14 1 <.01 6 1.3 1 <.01 .49 2 <.01 .09 1 <.01 7 1.3 1 <.01 .29 2 <.01 .21 1 <.01 8 1.1 1 <.01 .31 2 <.01 .10 1 <.01 9 .82 1 <.01 .13 2 <.01 .05 1 <.01 10 .76 1 <.01 .08 2 <.01 .03 1 <.01 11 .78 1 <.01 3.8 2 .02 .12 1 <.01 12 .83 1 <.01 1.5 2 .01 1.1 1 <.01 13 .87 1 <.01 .84 2 .01 4.8 1 .01 14 .94 1 <.01 .67 3 <.01 3.4 1 .01 15 .50 1 <.01 .41 3 <.01 1.7 1 <.01 16 .36 1 <.01 2.2 3 .02 3.3 1 .01 17 .38 1 <.01 5.2 3 .04 6.7 1 .02 18 .65 1 <.01 5.7 3 .04 5.3 1 .01 19 .27 1 <.01 9.6 3 .07 15 1 .04 20 .24 1 <.01 13 3 .10 13 1 .04 21 .23 1 <.01 10 3 .08 7.4 1 .02 22 .12 2 <.01 8.1 3 .06 8.3 1 .02 23 .10 2 <.01 6.3 3 .05 7.2 1 .02 24 .24 2 <.01 5.6 3 .04 4.5 1 .01 25 .47 2 <.01 4.7 2 .03 1.7 1 <.01 26 .36 2 <.01 3.8 2 .02 .32 1 <.01 27 .13 2 <.01 1.8 2 .01 3.9 1 .01 28 .07 2 <.01 5.3 2 .03 19 1 .05 29 .07 2 <.01 1.9 2 .01 4.2 1 .01 30 .07 2 <.01 .87 2 <.01 1.8 1 <.01 31 --- --- --- .57 2 <.01 --- --- --- TOTAL 18.59 --- 0.30 94.59 --- 0.78 118.50 --- 0.44 185 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 .96 1 <.01 1.1 1 <.01 3.2 20 .17 2 .96 1 <.01 .15 1 <.01 1.1 19 .06 3 1.1 1 <.01 1.1 1 <.01 2.1 18 .10 4 1.1 1 <.01 2.1 1 .01 1.9 17 .09 5 2.1 1 .01 1.7 1 .01 1.2 16 .05 6 2.5 1 .01 1.6 2 .01 1.6 15 .07 7 .97 1 <.01 1.5 2 .01 .00 0 <.01 8 .57 1 <.01 1.5 2 .01 84 29 26 9 .90 1 <.01 1.5 2 .01 4.1 22 .25 10 .76 1 <.01 .95 2 .01 3.2 19 .16 11 .68 1 <.01 .40 3 <.01 2.3 16 .10 12 .64 1 <.01 .59 3 <.01 2.4 13 .09 13 .59 1 <.01 1.3 3 .01 2.4 11 .07 14 .71 1 <.01 1.1 4 .01 2.1 9 .05 15 1.0 1 <.01 1.4 4 .02 2.2 8 .05 16 .94 1 <.01 2.3 5 .03 1.1 7 .02 17 .91 1 <.01 1.1 5 .01 9.9 6 .15 18 .87 1 <.01 1.8 6 .03 1530 160 790 19 1.1 1 <.01 2.7 7 .05 480 87 227 20 1.2 1 <.01 1.3 7 .03 577 84 226 21 .92 1 <.01 2.7 8 .06 37 27 6.2 22 1.5 1 <.01 4.1 9 .10 5.9 15 .25 23 1.2 1 <.01 8370 702 24700 334 56 100 24 1.8 1 <.01 507 292 758 1.8 15 .08 25 1.5 1 <.01 290 194 303 143 24 53 26 1.1 1 <.01 203 141 218 124 36 35 27 1.1 1 <.01 317 71 158 2.1 16 .09 28 1.2 1 <.01 3.4 18 .16 298 55 95 29 1.6 1 <.01 250 70 178 2.8 16 .12 30 2.2 1 .01 2.1 22 .12 3.3 9 .10 31 1.5 1 <.01 2.7 21 .16 --- --- --- TOTAL 36.18 --- 0.31 9979.19 --- 26315.91 3663.70 --- 1560.33 YEAR 92500.35 57223.90 < Actual value is known to be less than the value shown WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- SEDI- SED. CHARGE, MENT, SUSP. INST. SEDI- DIS- SIEVE CUBIC MENT, CHARGE, DIAM. FEET SUS- SUS- % FINER DATE TIME PER PENDED PENDED THAN SECOND (MG/L) (T/DAY) .062 MM (00061) (80154) (80155) (70331) OCT 19... 2030 1850 114 569 96 NOV 17... 0745 17400 84 3950 94 18... 1630 7080 356 6810 100 19... 0030 5920 403 6440 99 DEC 03... 1215 911 243 598 99 29... 1230 1200 32 104 95 FEB 20... 0445 1600 27 117 94 AUG 23... 1640 8190 1110 24500 100 24... 1820 1320 599 2130 100 186 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) AUG 23... 0810 35000 1150 109000 55 67 81 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) AUG 23... 93 98 100 100 100 100 100 187 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HIGHWAY 2 NEAR TOA ALTA, PR LOCATION.--Lat 18°24'41", long 66°15'39", Hydrologic Unit 21010005, on left bank, at downstream side of bridge on Highway 2, 1.3 mi ( 2.1 km) downstream from Río Lajas, and 1.6 mi (2.6 km) northwest of Toa Alta, 11.3 mi (18.2 km) downstream from Puerto Rico Aqueduct and Sewer Authority reservoir. DRAINAGE AREA.--208 mi2 (539 km2), excludes 8.2 mi2 (21.2 km2) upstream from Lago Carite, flow from which is diverted to Río Guamaní. Area at site used prior to September 25, 1984, 200 mi2 (518 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1959 (measurement only), January 1960 to current year. Prior to October 1984, published as Río de la Plata at Toa Alta, PR; October 1984 to September 1988 published as 50046900. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 9.15 ft (2.789 m), above mean sea level. Prior to October, 1984, at site about 1.0 mi (1.6 km) upstream at mean sea level datum. REMARKS.--Records poor. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. Gage-height and precipitation satellite telemetry at station. Flow affected by water extraction for La Virgencita water treatment plant by Puerto Rico Aqueduct and Sewer Authority of about 3.99 ft3/s (0.11 m3/s). Located about 1,000 ft upstream from station. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate discharges and elevations of major floods, as pointed out by local residents are as follows: Sept. 13, 1928, 120,000 ft3/s (3,400 m3/s), gage height, 37.4 ft (11.40 m); June 16, 1943, 82,000 ft3/s (2,322 m3/s), gage height, 34.4 ft (10.48 m), at site 1.0 mi upstream and different datum. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 87 590 806 218 55 41 23 18 22 25 24 39 2 409 320 7320 548 49 40 23 19 22 24 23 35 3 194 1300 3510 974 51 35 23 22 22 23 16 67 4 257 494 564 1350 49 32 21 25 22 26 19 51 5 64 157 2950 621 330 31 22 34 20 24 23 42 6 91 619 3380 707 59 32 22 25 21 20 16 84 7 109 148 1290 1960 50 36 23 26 23 52 17 76 8 147 92 1510 532 44 31 21 42 23 34 9.4 67 9 77 280 704 567 41 30 24 23 23 19 21 66 10 64 1030 671 320 41 29 36 13 22 17 15 32 11 387 848 616 434 38 29 32 360 56 22 13 36 12 135 353 407 123 36 29 22 126 130 18 13 25 13 334 866 433 414 37 29 21 39 91 15 13 25 14 76 1030 313 201 38 27 24 28 98 24 12 22 15 51 1640 394 412 38 26 25 26 49 16 17 21 16 193 1890 209 549 37 27 24 24 52 13 24 21 17 969 11900 449 132 53 45 20 16 57 22 19 999 18 160 13300 150 437 65 34 19 14 33 18 13 2250 19 556 6980 588 99 54 31 19 21 28 18 18 815 20 1910 3020 165 80 272 28 31 26 29 17 19 1000 21 1890 1280 595 316 77 27 31 37 38 18 15 532 22 844 952 639 110 259 33 21 26 31 15 21 572 23 231 739 479 71 261 29 19 24 25 13 11100 539 24 503 823 551 65 446 28 19 24 25 11 1270 190 25 681 731 672 363 462 30 16 23 24 13 548 80 26 1030 373 351 83 138 28 16 23 61 14 418 325 27 410 758 336 61 79 26 18 28 46 13 677 65 28 133 1560 265 60 50 29 19 28 27 11 88 253 29 101 931 1770 214 41 30 19 24 28 48 318 138 30 80 1280 987 253 --- 25 20 31 28 26 63 313 31 93 --- 527 62 --- 24 --- 23 --- 15 43 --- TOTAL 12266 56284 33601 12336 3250 951 673 1218 1176 644 14905.4 8780 MEAN 396 1876 1084 398 112 30.7 22.4 39.3 39.2 20.8 481 293 MAX 1910 13300 7320 1960 462 45 36 360 130 52 11100 2250 MIN 51 92 150 60 36 24 16 13 20 11 9.4 21 AC-FT 24330 111600 66650 24470 6450 1890 1330 2420 2330 1280 29560 17420 CFSM 1.90 9.02 5.21 1.91 .54 .15 .11 .19 .19 .10 2.31 1.41 IN. 2.19 10.07 6.01 2.21 .58 .17 .12 .22 .21 .12 2.67 1.57 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1960 - 2000, BY WATER YEAR (WY) MEAN 464 454 348 188 130 93.5 171 317 153 142 245 438 MAX 4813 2015 1352 929 409 468 722 1939 847 690 1677 3173 (WY) 1971 1985 1971 1992 1989 1969 1987 1985 1970 1961 1979 1996 MIN 18.8 18.4 14.8 16.9 16.0 8.31 5.07 7.63 11.4 13.2 16.5 19.2 (WY) 1995 1995 1995 1984 1983 1986 1984 1984 1977 1994 1976 1991 188 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HIGHWAY 2 NEAR TOA ALTA, PR--Continued SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1960 - 2000 ANNUAL TOTAL 134252 146084.4 ANNUAL MEAN 368 399 260 HIGHEST ANNUAL MEAN 824 1971 LOWEST ANNUAL MEAN 31.5 1994 HIGHEST DAILY MEAN 13300 Nov 18 13300 Nov 18 68100 Sep 10 1996 LOWEST DAILY MEAN 18 May 2 9.4 Aug 8 2.7 Apr 17 1984 ANNUAL SEVEN-DAY MINIMUM 20 Apr 29 13 Jul 22 2.9 Apr 15 1984 INSTANTANEOUS PEAK FLOW 34600 Aug 23 160000 Sep 10 1996 INSTANTANEOUS PEAK STAGE 21.08 Aug 23 27.33 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 266300 289800 188300 ANNUAL RUNOFF (CFSM) 1.77 1.92 1.25 ANNUAL RUNOFF (INCHES) 24.01 26.13 16.98 10 PERCENT EXCEEDS 747 845 484 50 PERCENT EXCEEDS 77 46 80 90 PERCENT EXCEEDS 23 18 18 O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 10,000 20,000 50,000 100,000 DISCHARGE, IN CUBIC FEET PER SECOND 189 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HWY 2 NR TOA ALTA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'41", long 66°15'39", at Highway 2, 1.3 mi (2.1 km) downstream from Río Lajas, and 1.6 mi (2.6 km) northwest of Toa Alta, 11.3 mi (18.2 km) downstream from Puerto Rico Aqueduct and Sewer Authority reservoir. DRAINAGE AREA.--208 mi2 (539 km2), exclude 8.2 mi2 (21.2 km2) upstream from Lago Carite, flow from which is diverted to Río Guamaní. PERIOD OF RECORD.--Water years 1958 to current year WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) OCT 19... 1045 288 292 7.7 27.7 9.8 5.0 64 10 3000 3100 FEB 08... 1320 43 432 7.7 26.0 2.3 7.6 93 <10 K14 <1 APR 13... 1400 22 466 7.7 27.6 .6 6.3 80 11 K82 K10 AUG 28... 1735 66 362 7.5 29.5 50 4.4 59 15 K1300 460 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) OCT 19... 110 27.6 9.65 15.6 .7 2.9 110 <1.0 12.4 19.2 FEB 08... -- -- -- -- -- -- 167 -- -- -- APR 13... 170 48.9 12.2 28.1 .9 3.1 164 <1.0 14.3 32.6 AUG 28... 140 40.4 9.74 16.7 .6 3.0 131 -- 13.9 20.1 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 19... .1 21.9 175 136 16 .41 .02 .4 .12 .45 FEB 08... -- -- -- -- <1 .94 .06 1.0 .19 .20 APR 13... .2 19.7 257 15.1 3 .62 .12 .7 .29 .16 AUG 28... .1 18.4 201 36.0 59 .73 .12 .9 .52 .48 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 19... .57 1.0 4.4 .060 <3 40.6 30 <.1 E1 <20 FEB 08... .39 1.4 6.2 .060 -- -- -- -- -- -- APR 13... .45 1.2 5.3 .080 E2 62.5 52 <.1 <1 <20 AUG 28... 1.0 1.9 8.2 .130 -- -- -- -- -- -- 190 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HWY 2 NR TOA ALTA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 19... 370 E1 52 <.3 <3 <1 <31 <.01 <4 .03 FEB 08... -- -- -- -- -- -- -- -- -- -- APR 13... 50 <1 165 <.3 <3 <1 <31 <.01 6 .04 AUG 28... -- -- -- -- -- -- -- -- -- -- 66°12 30
 18°27 30
 18°15
66°00
Basin area PUERTO RICO QUALITY-OF-WATER STATION AND NUMBER 047560 0476 047850 219 047550 EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SEDIMENT STATION AND NUMBER SURFACE-WATER STATION AND NUMBER Figure 17. Río Hondo to Río Puerto Nuevo basins. 191 Río Río Río Río Río Pu e r t o N u e vo Piedras Piedras Río Río Guaynabo Q u e b r a d a Quebrada Margarita San Antón de B a y a m ó n Hondo Canal del Río de Bayamón Minillas Lago de Cidra Lago Las Curias Represa de Río Piedras Laguna San José Laguna Martín Peña Bahía de San Juan TOA ALTA DORADO TOA BAJA CATAÑO SAN JUAN ATLANTIC OCEAN COMERIO CIDRA NARANJITO BAYAMÓN GUAYNABO TRUJILLO ALTO AGUAS BUENAS 0 0 1 1 2 2 3 3 4 4 5 MILES 5 KILOMETERS 047560 0476 047850 047990 048510 047530 049920 049820 0491 219 1151 1159 1152 1153 1154 1156 1158 1155 048770 048690 0488 047550 047549 048680 047537 047535 047540 192 RIO HONDO BASIN 50047530 RIO HONDO AT FLOOD CHANNEL NEAR CATAÑO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°26'13", long 66°09'36", at Río Hondo Channel, 800 ft (245 m) below junction with Río Hondo, 0.9 mi (1.5 km) downstream from bridge on de Diego Expressway and 1.1 mi (1.8 km) above mouth. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 PH OXYGEN, OXYGEN COLI- STREP- SPE- WATER DIS- DEMAND, FORM, TOCOCCI CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) NOV 18... 1045 470 8.0 25.2 98 4.4 55 29 30000 42000 MAR 01... 1400 1540 8.2 26.6 20 9.5 119 64 270 K10 APR 13... 1030 6800 7.7 27.5 25 3.8 49 54 42000 K18000 AUG 09... 1130 28300 8.1 33.5 24 5.6 87 62 420 400 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) NOV 18... 64 15.1 6.36 9.5 .5 2.7 90 <1.0 <.3 11.7 MAR 01... -- -- -- -- -- -- 162 -- -- -- APR 13... 610 69.3 107 884 16 37.8 162 <1.0 209 1630 AUG 09... 2800 188 567 4960 41 187 153 -- 1260 9330 SOLIDS, RESIDUE NITRO- FLUO- SILICA, SUM OF TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- RIDE, DIS- CONSTI- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + DIS- SOLVED TUENTS, DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC SOLVED (MG/L DIS- SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (00530) (00620) (00615) (00630) (00610) (00605) (00625) NOV 18... <.1 24.7 -- 122 .27 .04 .3 .21 .89 1.1 MAR 01... -- -- -- 16 .13 .05 .2 .40 1.3 1.7 APR 13... .3 16.7 3050 50 .27 .05 .3 1.20 .40 1.6 AUG 09... .4 7.4 16600 56 -- <.01 .3 .01 -- <.20 CHRO- BARIUM, BORON, CADMIUM MIUM, COPPER, IRON, NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL TOTAL GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE ERABLE DATE (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) AS FE) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) (01045) NOV 18... 1.4 6.2 .220 -- -- -- -- -- -- -- MAR 01... 1.9 8.3 .160 -- -- -- -- -- -- -- APR 13... 1.9 8.5 .250 E2 99.3 442 E.1 1 <20 1640 AUG 09... -- -- <.020 -- -- -- -- -- -- -- 193 RIO HONDO BASIN 50047530 RIO HONDO AT FLOOD CHANNEL NEAR CATAÑO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 18... -- -- -- -- -- -- -- -- -- MAR 01... -- -- -- -- -- -- -- -- -- APR 13... 2 511 <.3 <3 <1 E31 <.01 <4 .11 AUG 09... -- -- -- -- -- -- -- -- -- 194 RIO DE BAYAMON BASIN 50047535 RIO DE BAYAMON AT ARENAS, PR LOCATION.--Lat 18°10'11", long 66°07'18", Hydrologic Unit 21010005, at left bank, 2.61 mi (4.20 km) southeast of plaza de Cidra, 0.56 mi (0.90 km) southwest from Escuela Segunda Unidad de Bayamón, and 2.70 mi (4.34 km) northeast from Central Cayey. DRAINAGE AREA.--0.45 mi2 (1.16 km2). PERIOD OF RECORD.--July 1992 to September 1993, October 1995 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,378 ft (420 m), from topographic map. REMARKS.--Records fair, except those for estimated daily discharges, which are poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .51 .28 .63 1.3 .55 .39 .24 .06 .39 .19 .18 .11 2 .40 3.3 .70 .83 .44 .33 .22 .06 .33 .20 .15 .10 3 .35 1.2 .96 7.9 .43 .31 .22 .07 .28 .19 .13 .11 4 .38 .49 .63 2.6 .42 .30 .19 .06 .30 .20 .45 .11 5 .29 .50 12 1.9 .37 .31 .20 .06 .25 .17 .44 .11 6 .28 .75 4.0 3.3 .31 .31 .19 .06 .23 .16 .14 .09 7 .24 .48 5.7 2.4 .37 .30 .19 .05 .23 .16 .12 .08 8 .35 .37 2.4 1.3 .30 .33 .19 .05 .23 .18 .12 .08 9 .51 .32 1.5 .89 .28 .32 .17 .10 .21 .15 .11 .08 10 .35 e1.1 .94 .72 .27 .30 .15 .24 .20 .14 .09 .09 11 .27 e.60 .68 .63 .25 .26 .14 .85 .21 .14 .09 .17 12 .24 e2.2 .55 .57 .23 .28 .15 .64 1.5 .26 .09 .12 13 .23 e1.3 .51 .58 .22 .31 .16 .38 .53 .19 .09 .11 14 .21 e.89 .43 .76 .23 .31 .13 .32 .25 .29 .13 .11 15 .22 e1.3 .40 .97 .21 .30 .11 .30 .22 .20 .18 e.12 16 .23 e2.0 .38 1.2 .19 .28 .15 .29 1.4 .19 .21 e.11 17 .31 e48 .38 .67 .20 .27 .14 .33 .57 .20 .11 e1.1 18 .25 e25 .41 .61 .23 .28 .12 .31 .27 .21 .10 e8.9 19 .43 11 1.1 .58 .23 .26 .15 .31 .21 .20 .14 e1.6 20 5.7 4.2 2.0 .53 .23 .24 .11 .29 .21 .21 .12 e.74 21 5.1 2.2 .90 .58 .36 .24 .10 .31 .20 .19 .10 e.53 22 2.1 1.4 1.3 .58 .26 .24 .09 .27 .18 .16 1.0 e.35 23 .97 .99 .95 .53 1.6 .25 .09 .26 .17 .15 34 e.52 24 .51 .85 .86 .52 .68 .27 .08 .26 .25 .16 1.1 e.39 25 .36 .74 .65 .58 .78 .25 .08 .26 .23 .13 .84 e.25 26 .30 .68 .46 .56 .43 .33 .07 .24 .64 .13 3.0 e.20 27 .27 .64 .36 .50 .39 .49 .06 .23 .46 .13 1.2 e4.8 28 .24 .62 .71 .49 .33 .36 .06 .31 .24 .13 .48 e1.5 29 .23 .63 8.4 .61 .39 .32 .07 .32 .19 .17 .32 e.57 30 .22 .64 1.4 .52 --- .26 .08 1.5 .18 .14 .26 e.27 31 .25 --- 1.4 .46 --- .24 --- .64 --- .11 .15 --- TOTAL 22.30 114.67 53.69 36.17 11.18 9.24 4.10 9.43 10.76 5.43 45.64 23.42 MEAN .72 3.82 1.73 1.17 .39 .30 .14 .30 .36 .18 1.47 .78 MAX 5.7 48 12 7.9 1.6 .49 .24 1.5 1.5 .29 34 8.9 MIN .21 .28 .36 .46 .19 .24 .06 .05 .17 .11 .09 .08 AC-FT 44 227 106 72 22 18 8.1 19 21 11 91 46 CFSM 1.60 8.49 3.85 2.59 .86 .66 .30 .68 .80 .39 3.27 1.73 IN. 1.84 9.48 4.44 2.99 .92 .76 .34 .78 .89 .45 3.77 1.94 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1992 - 2000, BY WATER YEAR (WY) MEAN .74 1.31 1.25 .71 .67 .27 .20 .48 .62 .86 1.00 2.54 MAX 1.73 3.82 4.63 1.17 2.38 .65 .45 2.02 1.79 2.12 1.87 6.52 (WY) 1998 2000 1999 2000 1998 1998 1993 1993 1996 1993 1996 1998 MIN .30 .32 .048 .41 .16 .097 .095 .10 .10 .092 .46 .20 (WY) 1997 1998 1998 1998 1993 1993 1997 1999 1998 1998 1992 1997 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1992 - 2000 ANNUAL TOTAL 349.69 346.03 ANNUAL MEAN .96 .95 .91 HIGHEST ANNUAL MEAN 1.16 1996 LOWEST ANNUAL MEAN .31 1997 HIGHEST DAILY MEAN 48 Nov 17 48 Nov 17 141 Sep 10 1996 LOWEST DAILY MEAN .06 May 22 .05 May 7 .02 Jul 3 1997 ANNUAL SEVEN-DAY MINIMUM .07 May 18 .06 May 2 .03 Jun 28 1997 INSTANTANEOUS PEAK FLOW 203 Aug 23 1150 Sep 21 1998 INSTANTANEOUS PEAK STAGE 5.02 Aug 23 7.89 Sep 21 1998 INSTANTANEOUS LOW FLOW .02 Jul 15 1997 ANNUAL RUNOFF (AC-FT) 694 686 657 ANNUAL RUNOFF (CFSM) 2.13 2.10 2.01 ANNUAL RUNOFF (INCHES) 28.91 28.61 27.37 10 PERCENT EXCEEDS 1.4 1.3 1.2 50 PERCENT EXCEEDS .30 .30 .20 90 PERCENT EXCEEDS .11 .11 .07 e Estimated 195 RIO DE BAYAMON BASIN 50047535 RIO DE BAYAMON AT ARENAS, PR--Continued O N D 1999 J F M A M J J A S 2000 0.01 0.02 0.05 0.1 0.1 0.2 0.5 1 2 5 10 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND 196 RIO DE BAYAMON BASIN 50047540 RIO SABANA AT VISTA MONTE, PR LOCATION.--Lat 18°10'28", long 66°08'38", Hydrologic Unit 21010005, at left bank, 1.2 mi (1.9 km) southeast of Plaza de Cidra, 1.2 mi (1.9 km) southwest from Escuela Segunda Unidad de Bayamón, and 0.4 mi (0.6 km) upstream from Lago de Cidra. DRAINAGE AREA.--0.80 mi2 (2.07 km2). PERIOD OF RECORD.--August 1992 to September 1993, October 1995 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 1,345 ft (410 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .99 .46 .68 .99 e.82 .46 e.24 e.24 .09 .23 .52 .28 2 .80 .58 1.2 .81 e.68 .45 e.22 e.14 .09 .31 .28 .26 3 .60 .61 .94 13 e.75 .45 e.30 e.14 .10 .35 .27 .25 4 .53 .46 .66 3.2 e.67 .45 e.25 e.14 .14 .31 1.6 .25 5 .43 .80 12 2.3 e.60 .45 e.22 e.13 .10 .25 .69 .24 6 .40 .82 4.3 6.5 e.58 .44 e.19 e.12 .09 .22 .24 .25 7 .38 .58 5.8 3.0 e.66 .44 e.18 e.12 .09 .22 .24 .29 8 .41 .50 2.8 1.6 .57 .43 e.19 e.12 .08 .24 .22 .24 9 .52 .46 1.7 1.1 .57 .41 e.17 e.16 .08 .21 .20 .23 10 .53 2.4 1.3 .89 .54 .41 e.17 e.19 .08 .18 .18 .27 11 .86 .89 1.1 .82 .57 .43 e.17 .87 .10 .18 .17 .38 12 .39 7.7 .96 .75 .58 .43 e.23 .25 1.6 .37 .17 .26 13 .37 3.2 .86 .78 .66 .45 e.19 .16 .48 .38 .16 .25 14 .35 1.8 .83 .78 .67 .44 e.19 .14 .30 .30 .55 .24 15 .48 3.1 .79 .99 .58 e.53 e.20 .13 .26 .20 .56 e.22 16 .36 6.1 .73 1.1 .57 e.46 e.27 .12 1.8 .18 .52 e.22 17 .88 62 .75 .75 .65 e.43 e.21 .25 .40 .21 .21 e3.6 18 .45 33 .80 .72 .56 e.41 e.20 .21 .28 .19 .18 e8.7 19 2.9 11 1.6 .74 .60 e.37 e.23 .20 .24 .18 .21 e2.1 20 5.0 4.1 2.4 .75 .58 e.34 e.20 .15 .24 .20 .17 e.93 21 6.4 2.2 1.2 .71 .97 e.31 e.19 .15 .22 .18 .19 e.68 22 2.5 1.4 2.1 .69 .61 e.29 e.18 .13 .20 .17 1.8 e.63 23 1.4 1.0 1.3 .66 2.1 e.27 e.16 .12 .19 .16 84 e.59 24 .90 .95 1.5 .64 .70 e.26 e.15 .11 5.1 .16 2.1 e.53 25 1.5 .84 1.2 .63 1.8 e.24 e.16 .12 .70 .15 1.4 e.32 26 .63 .79 1.0 .60 .65 e.62 e.14 .10 1.5 .14 5.8 e.41 27 .52 .78 .95 .56 .51 e.32 e.13 .09 .57 .13 1.8 e8.0 28 .48 .73 1.6 .58 .47 e.22 e.13 .15 .32 .14 .88 e3.5 29 .45 .73 11 e.72 .48 e.26 e.14 .17 .25 .31 .57 e1.4 30 .43 .71 1.8 e.70 --- e.23 e.16 1.0 .22 .26 .40 e.75 31 .47 --- 1.3 e.68 --- e.24 --- .12 --- .22 .32 --- TOTAL 33.31 150.69 67.15 48.74 20.75 11.94 5.76 6.24 15.91 6.93 106.60 36.27 MEAN 1.07 5.02 2.17 1.57 .72 .39 .19 .20 .53 .22 3.44 1.21 MAX 6.4 62 12 13 2.1 .62 .30 1.0 5.1 .38 84 8.7 MIN .35 .46 .66 .56 .47 .22 .13 .09 .08 .13 .16 .22 AC-FT 66 299 133 97 41 24 11 12 32 14 211 72 CFSM 1.34 6.28 2.71 1.97 .89 .48 .24 .25 .66 .28 4.30 1.51 IN. 1.55 7.01 3.12 2.27 .96 .56 .27 .29 .74 .32 4.96 1.69 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1992 - 2000, BY WATER YEAR (WY) MEAN 2.04 2.28 2.12 1.07 1.15 .52 .57 .69 .79 1.33 1.68 5.17 MAX 4.51 5.02 7.83 1.91 3.50 1.01 1.23 2.26 1.57 3.02 3.44 16.7 (WY) 1998 2000 1999 1999 1998 1998 1993 1993 1999 1993 2000 1996 MIN .76 .86 .31 .33 .33 .15 .19 .20 .25 .22 .48 .25 (WY) 1997 1998 1998 1998 1993 1993 2000 2000 1997 2000 1997 1997 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1992 - 2000 ANNUAL TOTAL 552.35 510.29 ANNUAL MEAN 1.51 1.39 1.67 HIGHEST ANNUAL MEAN 2.37 1998 LOWEST ANNUAL MEAN .63 1997 HIGHEST DAILY MEAN 62 Nov 17 84 Aug 23 401 Sep 10 1996 LOWEST DAILY MEAN .17 May 22 .08 Jun 8 .08 Jun 8 2000 ANNUAL SEVEN-DAY MINIMUM .18 May 22 .09 Jun 5 .09 Jun 5 2000 INSTANTANEOUS PEAK FLOW 420 Aug 23 2380 Sep 10 1996 INSTANTANEOUS PEAK STAGE 5.31 Aug 23 12.02 Sep 10 1996 INSTANTANEOUS LOW FLOW .07 Jun 8 .07 Jun 8 2000 ANNUAL RUNOFF (AC-FT) 1100 1010 1210 ANNUAL RUNOFF (CFSM) 1.89 1.74 2.09 ANNUAL RUNOFF (INCHES) 25.68 23.73 28.36 10 PERCENT EXCEEDS 2.8 1.9 1.8 50 PERCENT EXCEEDS .58 .45 .49 90 PERCENT EXCEEDS .30 .15 .19 e Estimated 197 RIO DE BAYAMON BASIN 50047540 RIO SABANA AT VISTA MONTE, PR--Continued O N D 1999 J F M A M J J A S 2000 0.01 0.02 0.05 0.1 0.1 0.2 0.5 1 2 5 10 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND 198 RIO DE BAYAMON BASIN 50047550 LAGO CIDRA AT DAMSITE NEAR CIDRA, PR LOCATION.--Lat 18°11'57", long 66°08'29", Hydrologic Unit 21010005, at Lago de Cidra Dam on Río de Bayamón, 1.9 mi (3.0 km) northeast of Plaza de Cidra and 1.8 mi (2.9 km) northwest of Escuela Segunda Unidad de Bayamón. DRAINAGE AREA.--8.26 mi2 (21.39 km2). ELEVATION RECORDS PERIOD OF RECORD.--January 1988 to current year. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago de Cidra was completed in 1946. The maximum storage is 5,300 ac-ft (6.53 hm3) and provides supplemental water to metropolitan San Juan. The dam is a concrete gravity and earthfill structure approximately 541 ft (165 m) long between abutments with a maximum structural height of about 78.7 ft (24.0 m). The spillway portion of the dam, length 131 ft (40 m) and crest elevation 1,322 ft (403 m), is an ungated ogee crest located 131 ft (40 m) from the right abutment. This dam is owned by Puerto Rico Aqueduct and Sewer Authority. Gage-height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 99-4144,November 1997. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 1,328.09 ft (404.80 m), Sep. 10, 1996; minimum elevation 1,295.86 ft (394.98 m), April 22,1995. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 1,322.87 ft (403.21 m),Dec. 5;minimum elevation,1,299.14 ft (395.98 m), Aug.22. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 99-4144,Puerto Rico-1997) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 1,260 0 1,309 2,059 1,276 97 1,315 3,170 1,296 762 1,322 4,670 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1314.18 1313.59 1322.32 1322.39 1321.68 1319.06 1316.48 1312.75 1308.90 1307.40 1301.41 1312.51 2 1314.04 1313.74 1322.46 1322.39 1321.55 1319.01 1316.36 1312.60 1308.69 1307.20 1301.30 1312.43 3 1313.89 1313.75 1322.40 1322.68 1321.42 1318.94 1316.24 1312.46 1308.49 1306.99 1301.18 1312.36 4 1313.74 1313.73 1322.36 1322.48 1321.26 1318.86 1316.14 1312.45 1308.33 1306.76 1301.54 1312.26 5 1313.60 1313.90 1322.84 1322.48 1321.11 1318.80 1316.06 1312.31 1308.13 1306.53 1301.60 1312.12 6 1313.47 1313.98 1322.50 1322.67 1320.96 1318.73 1315.98 1312.17 1307.90 1306.30 1301.57 1312.01 7 1313.32 1313.97 1322.61 1322.49 1320.84 1318.65 1315.87 1312.01 1307.85 1306.04 1301.48 1311.86 8 1313.16 1313.94 1322.47 1322.43 1320.69 1318.60 1315.74 1311.87 1307.78 1305.79 1301.37 1311.64 9 1313.01 1313.92 1322.43 1322.38 1320.52 1318.55 1315.60 1311.71 1307.68 1305.56 1301.26 1311.43 10 1312.88 1314.75 1322.41 1322.37 1320.35 1318.47 1315.48 1311.57 1307.57 1305.39 1301.09 1311.25 11 1312.83 1314.84 1322.39 1322.35 1320.18 1318.37 1315.34 1311.80 1307.46 1305.20 1300.92 1311.13 12 1312.76 1315.26 1322.39 1322.33 1320.01 1318.26 1315.22 1311.75 1307.97 1305.08 1300.66 1310.97 13 1312.67 1315.46 1322.38 1322.36 1319.85 1318.14 1315.15 1311.68 1307.96 1305.02 1300.40 1310.78 14 1312.58 1315.61 1322.37 1322.35 1319.71 1318.02 1315.04 1311.60 1307.89 1304.90 1300.38 1310.61 15 1312.49 1315.81 1322.36 1322.42 1319.55 1317.91 1314.89 1311.46 1307.80 1304.75 1300.33 1310.46 16 1312.34 1316.23 1322.37 1322.37 1319.40 1317.84 1314.80 1311.29 1308.27 1304.58 1300.30 1310.29 17 1312.22 1319.79 1322.39 1322.35 1319.32 1317.77 1314.68 1311.15 1308.29 1304.44 1300.10 1310.52 18 1312.07 1321.65 1322.41 1322.34 1319.24 1317.71 1314.56 1311.01 1308.29 1304.28 1299.85 1310.96 19 1312.11 1322.38 1322.49 1322.33 1319.22 1317.64 1314.43 1310.87 1308.23 1304.09 1299.72 1311.16 20 1312.51 1322.45 1322.46 1322.33 1319.13 1317.59 1314.31 1310.71 1308.15 1303.88 1299.45 1311.25 21 1312.94 1322.41 1322.43 1322.32 1319.10 1317.47 1314.16 1310.54 1308.06 1303.67 1299.18 1311.34 22 1313.03 1322.38 1322.44 1322.32 1319.01 1317.37 1314.02 1310.29 1307.97 1303.46 1299.87 1311.42 23 1313.10 1322.36 1322.46 1322.32 1319.11 1317.27 1313.88 1310.10 1307.84 1303.26 1311.73 1311.44 24 1313.13 1322.35 1322.42 1322.31 1319.08 1317.17 1313.73 1309.91 1308.20 1303.08 1311.91 1311.54 25 1313.56 1322.34 1322.40 1322.31 1319.28 1317.05 1313.60 1309.75 1308.11 1302.81 1312.12 1311.56 26 1313.57 1322.33 1322.38 1322.28 1319.25 1317.06 1313.45 1309.57 1308.12 1302.55 1312.69 1311.56 27 1313.59 1322.32 1322.36 1322.20 1319.21 1317.01 1313.31 1309.38 1308.04 1302.26 1312.81 1311.82 28 1313.58 1322.33 1322.42 1322.09 1319.15 1316.94 1313.16 1309.20 1307.91 1301.97 1312.86 1311.97 29 1313.49 1322.34 1322.53 1322.00 1319.12 1316.83 1313.04 1309.03 1307.78 1301.76 1312.84 1312.03 30 1313.42 1322.33 1322.44 1321.89 --- 1316.72 1312.90 1309.22 1307.60 1301.52 1312.74 1312.07 31 1313.56 --- 1322.41 1321.77 --- 1316.61 --- 1309.09 --- 1301.34 1312.62 --- MAX 1314.18 1322.45 1322.84 1322.68 1321.68 1319.06 1316.48 1312.75 1308.90 1307.40 1312.86 1312.51 MIN 1312.07 1313.59 1322.32 1321.77 1319.01 1316.61 1312.90 1309.03 1307.46 1301.34 1299.18 1310.29 199 RIO DE BAYAMON BASIN 50047550 LAGO CIDRA AT DAMSITE NEAR CIDRA, PR--Continued O N D 1999 J F M A M J J A S 2000 1295 1300 1305 1310 1315 1320 1325 ELEVATION, IN FEET 200 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA, PR LOCATION.--Lat 18°12'04", long 66°08'26", Hydrologic Unit 21010005, 0.2 mi(0.3 km) downstream of Lago Cidra Dam on right bank, 2.1 mi (3.4 km) northwest of Cidra Plaza. DRAINAGE AREA.--8.32 mi2 (21.5 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,279 ft (390 m), from topographic map. REMARKS.--Records poor. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 9.5 13 9.1 e12 e24 11 19 e18 13 14 18 19 2 17 11 32 e12 e22 9.8 20 e18 12 15 16 14 3 17 11 80 e497 e27 13 21 18 12 15 14 13 4 22 10 28 e135 e28 16 19 19 11 16 13 14 5 24 12 900 e11 e28 11 22 19 12 15 13 20 6 23 11 658 e149 e28 14 22 18 13 14 11 17 7 23 13 463 e149 e27 18 20 19 13 14 10 17 8 26 12 223 e29 e26 17 20 20 12 13 10 20 9 27 12 72 e10 e28 17 20 20 10 13 e9.4 19 10 27 14 58 e4.8 29 16 21 19 11 15 9.8 18 11 20 9.0 25 e5.2 28 17 22 18 11 14 12 14 12 17 9.4 26 e3.6 28 17 21 10 17 14 13 13 13 17 e9.2 23 e5.2 29 21 20 11 10 e17 13 13 14 17 e8.9 13 e5.9 28 18 20 9.3 12 e18 21 13 15 22 e8.8 e11 e6.9 27 19 20 17 14 e15 15 12 16 24 9.3 e6.2 e35 26 20 19 20 12 e14 14 12 17 24 38 e4.4 e9.7 19 17 19 19 6.1 e15 13 13 18 24 42 e6.0 e4.0 14 17 18 17 5.3 e17 12 5.8 19 28 26 e22 e2.2 15 16 e19 17 10 e17 14 2.4 20 17 139 e79 e2.0 16 11 e18 18 14 e16 13 2.5 21 5.9 114 e28 e2.1 16 18 e20 19 14 e15 12 2.6 22 5.0 61 e37 e2.6 15 19 e20 20 14 e15 10 4.1 23 4.8 40 e43 e3.5 17 18 e22 14 17 e15 47 5.4 24 4.7 26 e47 e5.5 14 19 e21 11 19 e16 5.4 5.8 25 10 19 e26 e12 12 19 e20 12 18 e18 7.4 5.8 26 8.5 18 e14 e21 12 19 e19 12 18 e18 8.6 6.5 27 6.6 11 e10 e19 11 14 e20 12 16 e16 6.0 4.6 28 8.7 12 e16 e18 12 17 e19 12 17 e15 7.6 3.5 29 17 12 e579 e19 11 19 e18 12 19 15 12 3.2 30 17 12 e59 e20 --- 19 e17 9.3 16 15 21 3.3 31 19 --- e14 e22 --- 19 --- 7.9 --- 16 21 --- TOTAL 532.7 743.6 3611.7 1233.2 617 515.8 596 485.5 398.4 475 422.2 316.5 MEAN 17.2 24.8 117 39.8 21.3 16.6 19.9 15.7 13.3 15.3 13.6 10.6 MAX 28 139 900 497 29 21 22 20 19 18 47 20 MIN 4.7 8.8 4.4 2.0 11 9.8 17 7.9 5.3 13 5.4 2.4 AC-FT 1060 1470 7160 2450 1220 1020 1180 963 790 942 837 628 CFSM 2.07 2.98 14.0 4.78 2.56 2.00 2.39 1.88 1.60 1.84 1.64 1.27 IN. 2.38 3.32 16.15 5.51 2.76 2.31 2.66 2.17 1.78 2.12 1.89 1.42 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1991 - 2000, BY WATER YEAR (WY) MEAN 16.2 23.1 31.4 20.6 18.3 17.4 14.4 12.8 11.7 14.2 14.5 42.4 MAX 31.2 41.2 117 59.6 36.5 26.3 24.5 23.2 20.6 39.6 29.2 233 (WY) 1999 1992 2000 1992 1991 1998 1996 1998 1998 1993 1996 1996 MIN 3.74 8.85 4.36 5.45 7.24 11.4 5.72 4.13 3.47 1.56 1.18 1.64 (WY) 1995 1995 1994 1995 1994 1994 1997 1993 1994 1994 1995 1994 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1991 - 2000 ANNUAL TOTAL 9510.7 9947.6 ANNUAL MEAN 26.1 27.2 19.8 HIGHEST ANNUAL MEAN 36.1 1996 LOWEST ANNUAL MEAN 5.93 1994 HIGHEST DAILY MEAN 900 Dec 5 900 Dec 5 5420 Sep 10 1996 LOWEST DAILY MEAN 4.1 Apr 13 2.0 Jan 20 .60 Aug 6 1992 ANNUAL SEVEN-DAY MINIMUM 4.7 Apr 9 3.1 Jan 18 .80 May 1 1995 INSTANTANEOUS PEAK FLOW 1950 Dec 5 15000 Sep 10 1996 INSTANTANEOUS PEAK STAGE 16.20 Dec 5 27.34 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 18860 19730 14370 ANNUAL RUNOFF (CFSM) 3.13 3.27 2.38 ANNUAL RUNOFF (INCHES) 42.52 44.48 32.40 10 PERCENT EXCEEDS 26 28 28 50 PERCENT EXCEEDS 17 16 13 90 PERCENT EXCEEDS 8.9 6.6 3.6 e Estimated 201 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA, PR--Continued O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 202 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA , PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1991 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: November 1990 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1990. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected by hydrologic technician and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 7,610 mg/L November 17, 1999; Minimum daily mean, 3 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 27,700 tons (25,100 tonnes) September 10,1996; Minimum daily mean, 0.02 ton (0.02 tonne) November 21, 1993. EXTREMES FOR CURRENT YEAR 2000.-- SEDIMENT CONCENTRATION: Maximum daily mean, 7,610 mg/L November 17, 1999; Minimum daily mean, 3 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 23,100 tons (21,200 tonnes) December 15, 1999; Minimum daily mean, e0.10 ton (e0.09 tonne) January 19, 2000. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 9.5 52 1.4 13 73 2.6 9.1 160 3.9 2 17 79 3.7 11 40 1.2 32 140 12 3 17 77 3.5 11 33 .94 80 123 27 4 22 70 4.2 10 32 .86 28 108 8.2 5 24 64 4.1 12 775 75 900 6650 23100 6 23 59 3.7 11 61 1.9 658 2200 5320 7 23 53 3.3 13 47 1.6 463 5250 8000 8 26 47 3.2 12 40 1.3 223 507 438 9 27 42 3.1 12 35 1.1 72 63 12 10 27 40 2.9 14 1060 74 58 40 6.4 11 20 39 2.1 9.0 93 2.3 25 27 1.8 12 17 37 1.7 9.4 80 2.0 26 26 1.8 13 17 32 1.5 e9.2 e68 e1.7 23 28 1.7 14 17 26 1.2 e8.9 e57 e1.4 13 29 1.0 15 22 22 1.3 e8.8 e48 e1.1 e11 e31 e.96 16 24 18 1.2 9.3 476 39 e6.2 e38 e.64 17 24 18 1.1 38 7610 1020 e4.4 e48 e.57 18 24 18 1.1 42 7380 1180 e6.0 e60 e1.0 19 28 432 49 26 163 12 e22 e262 e23 20 17 93 4.4 139 328 131 e79 e75 e18 21 5.9 79 1.3 114 227 71 e28 e26 e2.0 22 5.0 68 .92 61 160 26 e37 e21 e2.1 23 4.8 58 .75 40 149 16 e43 e20 e2.4 24 4.7 48 .62 26 155 10 e47 e20 e2.5 25 10 403 31 19 162 8.4 e26 e19 e1.3 26 8.5 107 2.6 18 169 8.0 e14 e19 e.70 27 6.6 80 1.4 11 176 5.2 e10 e18 e.48 28 8.7 71 1.7 12 177 5.5 e16 e174 e18 29 17 64 3.0 12 176 5.5 e579 e1200 e774 30 17 57 2.7 12 175 5.5 e59 e83 e14 31 19 469 37 --- --- --- e14 e43 e1.6 TOTAL 532.7 --- 180.69 743.6 --- 2712.10 3611.7 --- 37797.05 203 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA , PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 e12 e33 e1.0 e24 e155 e9.9 11 5 .15 2 e12 e24 e.75 e22 e68 e4.1 9.8 5 .13 3 e497 e2010 e841 e27 e30 e2.2 13 4 .15 4 e135 e371 e84 e28 e13 e.99 16 4 .17 5 e11 e630 e59 e28 e6 e.48 11 4 .11 6 e149 e86 e70 e28 e6 e.42 14 3 .13 7 e149 e75 e32 e27 e5 e.39 18 3 .15 8 e29 e44 e3.5 e26 e5 e.35 17 4 .19 9 e10 e37 e1.0 e28 e5 e.35 17 5 .24 10 e4.8 e33 e.43 29 4 .34 16 7 .29 11 e5.2 e30 e.42 28 4 .32 17 9 .41 12 e3.6 e31 e.29 28 4 .31 17 10 .47 13 e5.2 e33 e.47 29 4 .34 21 12 .68 14 e5.9 e35 e.55 28 5 .37 18 12 .61 15 e6.9 e35 e.65 27 5 .39 19 10 .50 16 e35 e26 e2.6 26 6 .41 20 8 .44 17 e9.7 e19 e.50 19 6 .32 17 7 .30 18 e4.0 e14 e.15 14 7 .26 17 5 .24 19 e2.2 e16 e.10 15 7 .29 16 5 .19 20 e2.0 e20 e.11 16 8 .32 11 4 .12 21 e2.1 e25 e.14 16 9 .38 18 4 .17 22 e2.6 e30 e.22 15 10 .39 19 3 .16 23 e3.5 e36 e.34 17 11 .48 18 4 .19 24 e5.5 e43 e.64 14 10 .40 19 6 .28 25 e12 e49 e1.6 12 9 .30 19 8 .39 26 e21 e36 e1.9 12 8 .26 19 7 .39 27 e19 e23 e1.1 11 7 .22 14 7 .26 28 e18 e15 e.71 12 7 .21 17 6 .29 29 e19 e12 e.62 11 6 .17 19 7 .37 30 e20 e61 e3.4 --- --- --- 19 8 .42 31 e22 e252 e15 --- --- --- 19 8 .44 TOTAL 1233.2 --- 1124.19 617 --- 25.66 515.8 --- 9.03 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 19 8 .44 e18 e13 e.63 13 20 .69 2 20 9 .46 e18 e11 e.56 12 18 .58 3 21 9 .50 18 13 .63 12 17 .53 4 19 9 .45 19 15 .78 11 18 .54 5 22 9 .53 19 17 .85 12 22 .72 6 22 8 .47 18 19 .97 13 26 .92 7 20 7 .37 19 25 1.3 13 27 .91 8 20 6 .33 20 34 1.8 12 18 .56 9 20 6 .31 20 37 1.9 10 11 .31 10 21 5 .30 19 37 1.9 11 8 .22 11 22 5 .31 18 36 1.8 11 6 .18 12 21 7 .43 10 36 1.0 17 565 58 13 20 12 .66 11 36 1.0 10 80 2.4 14 20 21 1.1 9.3 31 .78 12 57 1.8 15 20 31 1.6 17 26 1.2 14 41 1.5 16 19 25 1.3 20 22 1.1 12 30 .99 17 19 19 .99 19 18 .92 6.1 22 .36 18 18 14 .69 17 14 .64 5.3 16 .22 19 e19 e11 e.55 17 10 .48 10 11 .29 20 e18 e10 e.50 18 8 .37 14 8 .30 21 e20 e10 e.53 19 7 .37 14 8 .29 22 e20 e10 e.56 20 8 .41 14 9 .34 23 e22 e11 e.62 14 8 .31 17 10 .48 24 e21 e11 e.64 11 9 .28 19 12 .59 25 e20 e12 e.63 12 11 .35 18 16 .79 26 e19 e13 e.67 12 13 .42 18 23 1.1 27 e20 e14 e.76 12 15 .50 16 28 1.2 28 e19 e16 e.80 12 17 .57 17 24 1.1 29 e18 e17 e.86 12 19 .64 19 20 1.0 30 e17 e15 e.72 9.3 22 .53 16 17 .72 31 --- --- --- 7.9 22 .47 --- --- --- TOTAL 596 --- 19.08 485.5 --- 25.46 398.4 --- 79.63 204 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA , PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 14 14 .53 18 526 47 19 233 12 2 15 10 .41 16 47 2.0 14 225 8.3 3 15 8 .32 14 42 1.6 13 217 7.4 4 16 6 .24 13 37 1.3 14 209 7.8 5 15 5 .20 13 33 1.1 20 201 11 6 14 24 .88 11 29 .88 17 193 8.7 7 14 21 .78 10 26 .74 17 178 8.3 8 13 14 .52 10 24 .67 20 162 8.7 9 13 14 .51 e9.4 e22 e.56 19 148 7.7 10 15 14 .59 9.8 20 .54 18 136 6.7 11 14 15 .57 12 19 .61 14 126 4.7 12 14 15 .57 13 18 .62 13 117 4.1 13 e17 e15 e.69 13 16 .56 13 108 3.9 14 e18 e15 e.75 21 434 38 13 100 3.4 15 e15 e15 e.64 15 140 5.8 12 93 3.0 16 e14 e16 e.60 14 88 3.4 12 86 2.7 17 e15 e16 e.66 13 68 2.4 13 79 2.8 18 e17 e16 e.72 12 52 1.7 5.8 73 1.2 19 e17 e17 e.79 14 40 1.5 2.4 68 .44 20 e16 e20 e.87 13 33 1.2 2.5 64 .43 21 e15 e22 e.90 12 27 .86 2.6 73 .51 22 e15 e25 e1.0 10 33 1.7 4.1 87 .99 23 e15 e28 e1.1 47 1800 720 5.4 102 1.5 24 e16 e32 e1.3 5.4 289 4.2 5.8 97 1.5 25 e18 e36 e1.8 7.4 385 7.8 5.8 85 1.3 26 e18 e39 e1.9 8.6 422 9.8 6.5 75 1.3 27 e16 e36 e1.6 6.0 416 6.7 4.6 76 .91 28 e15 e33 e1.3 7.6 405 8.3 3.5 80 .74 29 15 31 1.3 12 389 13 3.2 75 .65 30 15 29 1.2 21 319 18 3.3 71 .63 31 16 28 1.2 21 252 15 --- --- --- TOTAL 475 --- 26.44 422.2 --- 917.54 316.5 --- 123.30 YEAR 9947.6 43040.17 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- SEDI- SED. CHARGE, MENT, SUSP. INST. SEDI- DIS- SIEVE CUBIC MENT, CHARGE, DIAM. FEET SUS- SUS- % FINER DATE TIME PER PENDED PENDED THAN SECOND (MG/L) (T/DAY) .062 MM (00061) (80154) (80155) (70331) OCT 12... 1636 17 37 1.7 78 NOV 10... 1605 10 281 7.6 78 30... 1850 2.7 175 1.3 95 DEC 19... 1305 E55 379 56.3 86 20... 0405 E120 461 149 81 29... 1215 E707 134 256 69 29... 2000 E223 12100 7290 5 JAN 04... 1215 E60 55 8.9 66 06... 1810 E412 352 392 77 15... 1120 E2.7 37 .27 85 APR 05... 1640 24 9 .58 56 JUN 13... 0700 11 83 2.5 87 AUG 23... 0700 158 4920 2100 93 205 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA , PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) NOV 17... 1125 105 7490 2120 52 62 74 DEC 07... 0705 333 18700 16800 46 56 68 JAN 05... 1930 E40 16400 1770 45 56 66 AUG 23... 0100 207 10400 5790 49 61 74 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) NOV 17... 84 93 96 99 100 100 100 DEC 07... 74 86 87 96 99 100 100 JAN 05... 78 89 92 99 100 100 100 AUG 23... 85 94 96 99 99 100 100 206 RIO DE BAYAMON BASIN 50047600 RIO DE BAYAMON NEAR AGUAS BUENAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°14'39", long 66°08'39", at bridge on Highway 156, and 2.9 mi (4.7 km) west of Aguas Buenas plaza. DRAINAGE AREA.--18.5 mi2 (47.9 km2). PERIOD OF RECORD.--Water years 1958-65, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) OCT 26... 1730 22 266 7.9 25.6 39 7.5 96 <10 360 700000 FEB 11... 1300 43 263 8.3 22.5 6.7 8.8 105 <10 K54 22 APR 17... 1400 32 275 8.1 24.0 2.6 8.3 102 <10 K170 270 AUG 14... 1415 23 295 7.9 27.0 3.9 7.1 93 12 K120 390 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) OCT 26... 110 24.8 11.2 14.9 .6 2.8 98 <1.0 9.2 16.5 FEB 11... -- -- -- -- -- -- 90 -- -- -- APR 17... 93 21.2 9.66 14.9 .7 2.3 96 <1.0 7.3 19.9 AUG 14... 97 21.7 10.4 19.0 .8 1.9 100 -- 9.1 19.7 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 26... <.1 25.5 164 9.90 38 .79 .01 .8 .03 .46 FEB 11... -- -- -- -- 7 -- <.01 .6 .01 .20 APR 17... <.1 23.8 157 13.6 4 .45 .01 .5 .04 .20 AUG 14... .1 24.6 166 10.5 <10 .64 .01 .6 <.01 -- NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 26... .49 1.3 5.7 .070 <3 29.5 28 <.1 1 <20 FEB 11... .21 .77 3.4 .020 -- -- -- -- -- -- APR 17... .24 .70 3.1 <.020 <3 18.7 33 <.1 <1 <20 AUG 14... .21 .86 3.8 <.020 -- -- -- -- -- -- 207 RIO DE BAYAMON BASIN 50047600 RIO DE BAYAMON NEAR AGUAS BUENAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 26... 700 E1 107 <.3 <3 <1 <31 <.01 <4 <.16 FEB 11... -- -- -- -- -- -- -- -- -- -- APR 17... 150 <1 36 <.3 <3 <1 E26 <.01 <4 <.02 AUG 14... -- -- -- -- -- -- -- -- -- -- 208 RIO DE BAYAMON BASIN 50047850 RIO BAYAMON NR BAYAMON, PR LOCATION.--Lat 18°20'08", long 66°08'13", Hydrologic Unit 21010005, on left bank, at rock quarry near Highway 174, 1.3 mi (2.1km) south of colonia Santa Rosa and 4.7 mi (7.6 km) south of Bayamón. DRAINAGE AREA.--41.8 mi2 (108.3 km2). PERIOD OF RECORD.--September 1964 to October 1970, June 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 98 ft (30 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Diversion to the Guaynabo water treatment plant, for municipal supply, made upstream from station (at Represa de San Juan). Flow is regulated by storage and release of water at Lago de Cidra (capacity 5,220 acre-ft), 10.5 mi(16.9 km) upstream. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 22 63 e78 75 40 20 14 10 9.4 8.4 9.3 11 2 21 213 e127 64 37 20 14 10 10 8.8 9.0 11 3 20 148 e356 295 38 20 14 11 9.3 8.7 29 11 4 19 72 151 266 37 19 13 11 9.1 8.5 13 11 5 19 164 1070 148 34 19 14 18 8.5 8.1 11 12 6 176 183 590 182 33 18 13 13 8.0 7.7 7.7 12 7 36 67 279 212 34 18 13 11 8.1 7.0 7.5 12 8 55 40 231 104 34 18 12 10 8.0 7.0 7.2 11 9 29 29 131 81 32 18 12 10 8.0 7.2 6.8 11 10 29 e461 100 60 29 17 12 9.9 8.3 7.1 6.7 11 11 48 117 83 51 29 17 12 53 9.5 7.2 6.2 13 12 93 45 73 44 28 17 12 70 48 8.1 6.3 11 13 32 32 64 70 29 16 13 23 35 20 6.0 10 14 25 55 57 69 28 16 12 12 11 11 5.8 10 15 23 228 51 66 27 16 11 11 11 6.4 5.7 11 16 248 144 47 94 26 17 11 10 177 6.2 6.1 16 17 135 1250 46 51 25 17 11 11 34 6.6 5.8 136 18 218 1250 52 43 30 16 11 53 11 7.0 5.4 318 19 167 729 58 39 27 15 11 21 9.4 6.8 5.7 115 20 547 310 81 36 35 14 11 11 8.5 8.1 5.0 174 21 693 192 71 35 23 15 10 11 8.5 7.5 4.7 34 22 e298 152 125 34 28 17 10 9.7 8.3 7.2 9.5 20 23 e72 e169 89 34 42 14 10 10 8.2 7.1 2320 20 24 e32 e124 148 34 38 14 10 9.4 8.3 7.2 75 17 25 e158 e167 124 34 82 14 9.9 9.4 8.2 7.3 23 16 26 e51 e154 74 33 29 14 10 9.1 11 6.9 16 14 27 32 e96 52 32 24 19 10 9.3 9.0 6.9 14 15 28 32 e92 70 35 21 15 10 9.0 8.6 7.0 12 21 29 28 e110 382 43 21 15 10 8.5 8.3 11 12 16 30 28 e96 112 40 --- 14 11 18 8.1 8.4 12 13 31 117 --- 85 36 --- 14 --- 12 --- 7.5 13 --- TOTAL 3503 6952 5057 2440 940 513 346.9 504.3 527.6 249.9 2676.4 1113 MEAN 113 232 163 78.7 32.4 16.5 11.6 16.3 17.6 8.06 86.3 37.1 MAX 693 1250 1070 295 82 20 14 70 177 20 2320 318 MIN 19 29 46 32 21 14 9.9 8.5 8.0 6.2 4.7 10 AC-FT 6950 13790 10030 4840 1860 1020 688 1000 1050 496 5310 2210 CFSM 2.70 5.54 3.90 1.88 .78 .40 .28 .39 .42 .19 2.07 .89 IN. 3.12 6.19 4.50 2.17 .84 .46 .31 .45 .47 .22 2.38 .99 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1964 - 2000, BY WATER YEAR (WY) MEAN 41.4 55.6 56.9 38.6 23.9 18.0 19.6 35.5 20.4 23.5 45.1 65.9 MAX 129 232 263 159 75.3 52.9 72.7 131 60.8 79.2 137 360 (WY) 1991 2000 1966 1969 1989 1990 1971 1966 1970 1999 1970 1996 MIN 4.30 7.91 3.45 5.30 4.75 3.58 5.36 4.85 3.68 4.01 7.47 6.02 (WY) 1969 1965 1998 1968 1965 1965 1965 1994 1994 1994 1994 1967 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1964 - 2000 ANNUAL TOTAL 27523.9 24823.1 ANNUAL MEAN 75.4 67.8 37.1 HIGHEST ANNUAL MEAN 69.5 1999 LOWEST ANNUAL MEAN 10.9 1994 HIGHEST DAILY MEAN 1250 Nov 17 2320 Aug 23 8640 Sep 10 1996 LOWEST DAILY MEAN 6.6 May 27 4.7 Aug 21 2.2 Apr 19 1965 ANNUAL SEVEN-DAY MINIMUM 7.1 May 22 5.5 Aug 15 2.4 Apr 14 1965 INSTANTANEOUS PEAK FLOW 12800 Aug 23 65000 Sep 10 1996 INSTANTANEOUS PEAK STAGE 17.07 Aug 23 29.07 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 54590 49240 26910 ANNUAL RUNOFF (CFSM) 1.80 1.62 .89 ANNUAL RUNOFF (INCHES) 24.49 22.09 12.07 10 PERCENT EXCEEDS 170 151 64 50 PERCENT EXCEEDS 29 18 13 90 PERCENT EXCEEDS 9.3 7.9 5.2 e Estimated 209 RIO DE BAYAMON BASIN 50047850 RIO BAYAMON NR BAYAMON, PR--Continued O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 210 RIO DE BAYAMON BASIN 50047990 RIO GUAYNABO NEAR BAYAMON, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°22'32", long 66°07'59", at bridge on Highway 833, 0.2 mi (0.3 km) upstream from Río de Bayamón, and 2.3 mi (3.7 km) southeast of Bayamón plaza. DRAINAGE AREA.--19.8 mi2 (51.2 km2). PERIOD OF RECORD.--Water years 1958, 1964, 1971-73, 1976, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 PH OXYGEN, OXYGEN COLI- STREP- SPE- WATER DIS- DEMAND, FORM, TOCOCCI CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) OCT 22... 1100 350 7.6 26.0 60 5.9 74 <10 27000 9300 FEB 28... 1310 452 7.9 25.3 8.1 4.3 52 16 2200 K100 APR 13... 1055 461 7.8 24.7 7.0 5.3 63 12 K1500 290 AUG 30... 1030 531 7.9 27.7 11 1.8 23 11 K7000 500 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) OCT 22... 120 31.7 9.70 18.5 .7 3.0 117 <1.0 14.5 20.9 FEB 28... -- -- -- -- -- -- 166 -- -- -- APR 13... 150 40.5 11.8 22.4 .8 2.5 167 <1.0 10.9 36.0 AUG 30... 180 50.4 13.6 29.3 .9 3.4 185 -- 22.7 34.0 SOLIDS, RESIDUE NITRO- FLUO- SILICA, SUM OF TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- RIDE, DIS- CONSTI- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + DIS- SOLVED TUENTS, DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC SOLVED (MG/L DIS- SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (00530) (00620) (00615) (00630) (00610) (00605) (00625) OCT 22... .1 27.9 197 20 1.16 .04 1.2 .14 .69 .83 FEB 28... -- -- -- 30 .92 .06 1.0 .18 .82 1.0 APR 13... .2 24.9 249 25 .50 .05 .6 .14 .24 .38 AUG 30... .2 27.9 293 <10 .68 .06 .7 .90 .02 .92 CHRO- BARIUM, BORON, CADMIUM MIUM, COPPER, IRON, NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL TOTAL GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE ERABLE DATE (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) AS FE) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) (01045) OCT 22... 2.0 9.0 .180 <3 112 28 <.1 3 24 3260 FEB 28... 2.0 8.8 .390 -- -- -- -- -- -- -- APR 13... .93 4.1 .220 E1 110 50 <.1 <1 <20 510 AUG 30... 1.7 7.3 .180 -- -- -- -- -- -- -- 211 RIO DE BAYAMON BASIN 50047990 RIO GUAYNABO NEAR BAYAMON, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 22... 3 172 <.3 <3 <1 <31 <.01 <4 .09 FEB 28... -- -- -- -- -- -- -- -- -- APR 13... E1 257 <.3 <3 <1 E20 <.01 <4 .03 AUG 30... -- -- -- -- -- -- -- -- -- 212 RIO DE BAYAMON BASIN 50048510 RIO DE BAYAMON AT FLOOD CHANNEL AT BAYAMON, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'29", long 66°09'04", at bridge on Highway 890, 1.0 mi (1.6 km) downstream from bridge on Highway 2, and 3.2 mi (5.1 km) above mouth. DRAINAGE AREA.--71.9 mi2 (186.2 km2). PERIOD OF RECORD.--Water years 1974 to current year. REMARKS.--Prior to 1979 sampling site was 0.8 mile (1.3 km) downstream but was changed because of flood channel construction. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) OCT 22... 0915 E300 262 7.9 25.0 92 7.4 91 <10 K6800 4500 FEB 28... 1130 59 432 7.9 23.6 9.5 7.3 85 <10 59000 890 MAY 03... 1040 20 463 7.8 26.3 4.1 6.8 83 <10 K10000 540 SEP 05... 1045 6.2 482 7.6 29.9 16 6.8 89 10 K1000 K45 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) OCT 22... 97 24.6 8.63 14.0 .6 2.4 98 <1.0 11.5 16.2 FEB 28... -- -- -- -- -- -- 163 -- -- -- MAY 03... 170 43.4 15.4 26.0 .9 2.0 182 <1.0 11.7 35.4 SEP 05... 180 48.0 14.9 23.8 .8 2.7 179 -- 19.0 31.4 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 22... .1 25.7 162 -- 126 1.08 .02 1.1 .05 .60 FEB 28... -- -- -- -- 8 .72 .04 .8 .33 .19 MAY 03... .1 31.1 274 14.9 22 .18 .02 .2 .11 .20 SEP 05... .1 26.1 273 4.57 23 .18 .09 .3 .10 .32 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 22... .65 1.8 7.7 .160 <3 83.9 30 <.1 5 21 FEB 28... .52 1.3 5.7 .130 -- -- -- -- -- -- MAY 03... .31 .51 2.3 .080 E2 79.4 39 <.1 E1 <20 SEP 05... .42 .69 3.1 .070 -- -- -- -- -- -- 213 RIO DE BAYAMON BASIN 50048510 RIO DE BAYAMON AT FLOOD CHANNEL AT BAYAMON, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 22... 4340 3 223 <.3 <3 <1 <31 <.01 <4 <.08 FEB 28... -- -- -- -- -- -- -- -- -- -- MAY 03... 570 <1 226 <.3 <3 <1 <31 <.01 <4 .02 SEP 05... -- -- -- -- -- -- -- -- -- -- CHLOR- DANE, P,P'- P,P'- ENDO- TECH- DDD P,P'- DDT DI- DI- SULFAN PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I DATE TOTAL TOTAL TOTAL RECOVER TOTAL RECOVER TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39516) (39330) (39350) (39360) (39365) (39370) (39570) (39380) (39388) OCT 22... -- -- -- -- -- -- -- -- -- FEB 28... -- -- -- -- -- -- -- -- -- MAY 03... <.1 <.013 <.1 <.014 <.016 <.017 E.01 <.009 <.015 SEP 05... -- -- -- -- -- -- -- -- -- ENDRIN HEPTA- METH- METHYL WATER HEPTA- CHLOR MALA- OXY- PARA- UNFLTRD ETHION, CHLOR, EPOXIDE LINDANE THION, CHLOR, THION, MIREX, DATE REC TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39390) (39398) (39410) (39420) (39340) (39530) (39480) (39600) (39755) OCT 22... -- -- -- -- -- -- -- -- -- FEB 28... -- -- -- -- -- -- -- -- -- MAY 03... <.014 <.01 <.011 <.009 <.012 <.03 <.01 <.01 <.01 SEP 05... -- -- -- -- -- -- -- -- -- CARBO- PHENO- PCNS PARA- PER- TOX- THION UNFILT THION, THANE APHENE, WATER 2,4-D, 2,4,5-T 2,4-DP SILVEX, DATE RECOVER TOTAL TOTAL TOTAL UNFLTRD TOTAL TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39250) (39540) (39034) (39400) (39786) (39730) (39740) (82183) (39760) OCT 22... -- -- -- -- -- -- -- -- -- FEB 28... -- -- -- -- -- -- -- -- -- MAY 03... <.1 <.01 <.1 <1 <.01 <.05 <.03 <.04 <.03 SEP 05... -- -- -- -- -- -- -- -- -- 214 RIO PUERTO NUEVO BASIN 50048680 LAGO LAS CURIAS AT DAMSITE NEAR RIO PIEDRAS, PR LOCATION.--Lat 18°20'23", long 66°03'05", Hydrologic Unit 21010005 at Lago Las Curias Dam on Río Piedras, 4.15 mi (6.67 km) south of University of Puerto Rico Tower, 1.6 mi (2.57 km) northwest from Escuela José F. Díaz and 0.8 mi (1.28 km) north of Escuela Cupey Alto. DRAINAGE AREA.--0.97 mi2 (2.51 km2). ELEVATION RECORDS PERIOD OF RECORD.--April 1997 to current year. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Las Curias was completed in 1946. The reservoir has a capacity of 1,135 ac-ft (1.40 hm3) at spillway crest elevation 315.78 ft (96.25 m) for water supply. The dam is earthfill and has a crest elevation of 327.3 ft (99.75 m). Masonry parapet walls continous from abutment on each side of the 25 ft (7.62 m) wide crest. The dam is about 82.0 ft (25.0 m) high and 984.2 ft (300.0 m) long. The morning-glory inlet conduit spillway in located along the left abutment of the dam and has an uncontrolled capacity of about 5,000 ft3/s (141.6 m3/s) at reservoir elevation 321.5 ft (98.0 m). This dam is operated by Puerto Rico Aqueduct and Sewer Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 317.01 ft (96.62 m),Aug. 11, 1998; minimum elevation, 313.04 ft (95.41 m), Oct. 5, 1998. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 316.90 ft (96.59 m), Aug. 23; minimum elevation, 315.41 ft (96.14 m), Aug. 22. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 284.7 154 313.0 677 298.2 462 314.3 1,078 307.1 770 317.5 1,232 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 315.85 315.86 315.90 315.86 315.85 315.83 315.85 315.73 315.77 315.73 315.63 315.80 2 315.84 315.86 316.26 315.91 315.86 315.84 315.84 315.73 315.79 315.81 315.62 315.82 3 315.84 315.86 315.90 315.89 315.85 315.84 315.85 315.80 315.78 315.80 315.63 315.81 4 315.84 315.87 315.88 315.90 315.85 315.83 315.84 315.88 315.76 315.79 315.76 315.81 5 315.85 315.86 316.04 315.88 315.84 315.84 315.84 315.88 315.74 315.78 315.75 315.90 6 315.85 315.86 315.90 315.96 315.85 315.84 315.84 315.85 315.73 315.77 315.74 315.83 7 315.87 315.89 315.93 315.88 315.85 315.84 315.83 315.85 315.72 315.78 315.76 315.82 8 315.87 315.94 315.89 315.87 315.84 315.83 315.82 315.84 315.71 315.76 315.74 315.82 9 315.86 315.95 315.88 315.87 315.84 315.84 315.82 315.84 315.70 315.76 315.72 315.81 10 315.85 315.90 315.88 315.86 315.84 315.82 315.87 315.82 315.69 315.74 315.71 315.82 11 315.86 315.88 315.87 315.86 315.87 315.81 315.84 315.93 315.69 315.73 315.69 315.81 12 315.89 A 315.88 315.86 315.84 315.82 315.83 315.88 315.85 315.71 315.69 315.80 13 315.85 A 315.88 315.89 315.84 315.82 315.86 315.85 315.85 315.71 315.67 315.79 14 315.84 315.90 315.87 315.87 315.84 315.82 315.83 315.86 315.84 315.69 315.67 315.79 15 315.85 315.91 315.87 315.92 315.84 315.82 315.82 315.85 315.84 315.68 315.67 315.78 16 315.94 315.90 315.87 315.87 315.84 315.84 315.82 315.84 315.83 315.66 315.69 315.78 17 315.90 315.88 315.87 315.86 315.84 315.83 315.81 315.84 315.80 315.67 315.68 315.84 18 315.86 315.87 315.88 315.86 315.86 315.83 315.82 315.84 315.80 315.68 315.67 315.82 19 316.04 315.89 315.88 315.86 315.85 315.83 315.82 315.83 315.79 315.67 315.67 315.83 20 315.94 315.89 315.88 315.86 315.84 315.83 315.81 315.84 315.79 315.72 315.66 315.82 21 315.93 315.88 315.88 315.86 315.86 315.83 315.80 315.83 315.79 315.71 315.65 315.85 22 315.86 315.91 315.89 315.86 315.87 315.83 315.79 315.85 315.77 315.70 315.43 315.91 23 315.88 315.89 315.90 315.86 315.85 315.84 315.79 315.77 315.76 315.69 315.88 315.90 24 315.88 315.94 315.91 315.85 315.85 315.84 315.78 315.77 315.76 315.68 315.84 315.85 25 315.86 315.99 315.88 315.85 315.85 315.84 315.77 315.76 315.75 315.66 315.86 315.83 26 315.85 315.90 315.87 315.84 315.86 315.84 315.76 315.75 315.78 315.64 315.85 315.83 27 315.85 315.90 315.87 315.85 315.84 315.83 315.76 315.75 315.76 315.62 315.85 315.83 28 315.85 315.93 315.89 315.86 315.84 315.87 315.76 315.80 315.75 315.61 315.86 315.84 29 315.85 315.90 315.88 315.86 315.83 315.84 315.75 315.77 315.74 315.63 315.83 315.82 30 315.87 315.89 315.87 315.85 --- 315.85 315.74 315.80 315.73 315.62 315.81 315.82 31 315.96 --- 315.86 315.85 --- 315.88 --- 315.77 --- 315.62 315.81 --- MAX 316.04 315.99 316.26 315.96 315.87 315.88 315.87 315.93 315.85 315.81 315.88 315.91 MIN 315.84 315.86 315.86 315.84 315.83 315.81 315.74 315.73 315.69 315.61 315.43 315.78 A No gage-height record 215 RIO PUERTO NUEVO BASIN 50048680 LAGO LAS CURIAS AT DAMSITE NEAR RIO PIEDRAS, PR--Continued O N D 1999 J F M A M J J A S 2000 315.4 315.6 315.8 316 316.2 316.4 ELEVATION, IN FEET Gap indicates missing record 216 RIO PUERTO NUEVO BASIN 50048690 QUEBRADA LAS CURIAS BELOW LAS CURIAS DAM, PR LOCATION.--Lat 18°20'43", long 66°03'08", Hydrologic Unit 21010005, at 0.20 miles (0.32 km) from Lago Las Curias Dam on Río Piedras, 4.13 mi (6.64 km) south of University of Puerto Rico Tower, 2.55 mi (4.10 km) northwest from Lago Loíza spillway crest and 0.85 mi (1.37 km) north of Escuela Cupey Alto. DRAINAGE AREA.--1.08 mi2 (2.79 km2). PERIOD OF RECORD.--August 1997 to current year. GAGE.--Water stage recorder. Elevation of gage is 262.47 ft (80.0 km), from topographic map. REMARKS.--Records poor. Flow completly regulated by Lago Las Curias Dam, 0.20 mi (0.32 km) from gage. Gage-height and precipitation satellite telemetry at station.. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .63 7.2 2.7 2.1 e1.2 .55 1.4 .38 .43 .36 .29 .35 2 .37 2.0 52 1.6 e.86 .55 .53 .40 .53 .49 .29 .35 3 .33 1.7 18 12 e1.0 .50 .53 .50 .64 .73 .31 .58 4 .46 3.0 3.4 8.7 e.87 .53 .47 2.0 .65 .44 .39 .42 5 .53 2.8 37 8.7 e.80 .47 .52 2.0 .36 .48 .44 15 6 .44 2.2 15 4.8 e.70 .51 .45 .95 .41 .26 .26 3.8 7 2.0 4.7 8.1 8.9 e1.8 .52 .71 .43 .33 .24 .35 .64 8 3.3 24 8.1 2.5 e.84 .55 .60 .40 .38 .44 .46 .46 9 1.3 27 3.8 1.8 e.76 .43 .40 e.29 .43 .25 .24 .56 10 .55 23 2.9 e1.4 e.68 .63 1.7 e.28 .36 .31 .24 .36 11 .56 4.9 2.5 e1.2 e1.5 .59 1.4 e2.0 .41 .32 .26 1.4 12 5.5 5.7 2.3 e1.0 e.83 .43 1.1 e.41 4.4 .29 .22 .39 13 1.9 e3.2 2.2 e5.1 e.82 .40 1.1 e.29 6.4 .22 .22 .28 14 .87 e5.0 2.1 e3.9 e.84 .48 .94 e.27 6.2 .33 .24 .28 15 .55 24 1.7 e3.3 e.68 .47 .62 e.31 2.4 .25 .25 .29 16 7.9 9.0 1.8 e3.0 e.68 .51 .31 .34 1.8 .23 .26 .32 17 17 40 2.1 e1.6 e.68 1.4 .61 .26 1.0 .28 .26 1.5 18 3.0 18 2.2 e1.2 e2.4 .57 .44 .24 .59 .33 .26 1.8 19 8.1 12 2.0 e1.2 e2.5 .38 .41 .24 .41 .33 .27 1.5 20 28 6.2 2.0 e1.3 e.83 .28 .50 .26 .41 .34 .27 .75 21 34 3.3 2.4 e.90 e.99 .29 .30 .26 .38 .32 .27 2.5 22 7.4 11 7.5 e.81 e2.1 .66 .52 .29 .43 .27 12 31 23 5.1 4.1 5.1 e.74 e.81 .41 .52 .39 .46 .30 66 20 24 4.5 9.3 4.7 e.73 e1.1 .47 .42 .40 .36 .28 2.6 5.1 25 2.3 65 4.8 e1.3 2.9 .41 .44 .57 .49 .27 1.4 1.6 26 1.6 9.4 1.8 e.77 1.4 .39 .44 .54 .36 .28 2.0 .82 27 1.3 3.3 1.3 e.99 1.3 .55 .45 .41 .48 .26 1.5 1.1 28 .92 5.4 5.6 .75 .85 1.1 .31 .49 .42 .28 3.8 .80 29 .98 4.3 4.3 1.9 .90 2.1 .33 1.1 .31 .32 1.3 .79 30 1.8 2.7 2.2 1.5 --- .52 .36 1.9 .36 .31 .67 .64 31 11 --- 1.6 1.1 --- 3.4 --- .98 --- .27 .53 --- TOTAL 154.19 343.4 213.2 86.79 33.62 21.05 18.83 19.58 32.59 10.08 97.85 95.38 MEAN 4.97 11.4 6.88 2.80 1.16 .68 .63 .63 1.09 .33 3.16 3.18 MAX 34 65 52 12 2.9 3.4 1.7 2.0 6.4 .73 66 31 MIN .33 1.7 1.3 .73 .68 .28 .30 .24 .31 .22 .22 .28 AC-FT 306 681 423 172 67 42 37 39 65 20 194 189 CFSM 4.33 9.95 5.98 2.43 1.01 .59 .55 .55 .94 .28 2.74 2.76 IN. 4.99 11.11 6.90 2.81 1.09 .68 .61 .63 1.05 .33 3.17 3.09 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1997 - 2000, BY WATER YEAR (WY) MEAN 4.78 6.44 5.86 2.75 1.76 1.17 .89 .80 1.75 1.63 4.12 4.69 MAX 5.90 11.4 10.2 4.63 2.51 2.52 1.24 1.50 3.64 3.51 7.06 12.2 (WY) 1999 2000 1999 1999 1999 1999 1999 1999 1999 1999 1998 1998 MIN 3.46 .92 .51 .83 1.16 .33 .63 .29 .52 .33 2.15 1.03 (WY) 1998 1998 1998 1998 2000 1998 2000 1998 1998 2000 1999 1997 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1997 - 2000 ANNUAL TOTAL 1443.14 1126.56 ANNUAL MEAN 3.95 3.08 3.16 HIGHEST ANNUAL MEAN 3.95 1999 LOWEST ANNUAL MEAN 2.46 1998 HIGHEST DAILY MEAN 65 Nov 25 66 Aug 23 96 Sep 22 1998 LOWEST DAILY MEAN .28 May 18 .22 Jul 13 .17 Oct 7 1998 ANNUAL SEVEN-DAY MINIMUM .35 May 16 .24 Aug 9 .19 Jun 26 1998 INSTANTANEOUS PEAK FLOW 398 Aug 23 431 Aug 11 1998 INSTANTANEOUS PEAK STAGE 11.51 Aug 23 11.70 Aug 11 1998 ANNUAL RUNOFF (AC-FT) 2860 2230 2290 ANNUAL RUNOFF (CFSM) 3.66 2.85 2.93 ANNUAL RUNOFF (INCHES) 49.71 38.80 39.75 10 PERCENT EXCEEDS 9.1 6.6 7.9 50 PERCENT EXCEEDS 1.7 .75 .81 90 PERCENT EXCEEDS .52 .28 .28 e Estimated 217 RIO PUERTO NUEVO BASIN 50048690 QUEBRADA LAS CURIAS BELOW LAS CURIAS DAM, PR--Continued O N D 1999 J F M A M J J A S 2000 0.1 0.2 0.5 1 2 5 10 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND 218 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR LOCATION.--Lat 18°21'51", long 66°03'56", Hydrologic Unit 21010005,on right bank, in the Riberas of Señorial Housing areas, 0.6 mi (1.0 km) west of Highway 176 and 2.7 mi (4.3 km)southwest of Río Piedras Plaza. DRAINAGE AREA.--7.49 mi2 (19.40 km2). WATER DISCHARGE RECORDS PERIOD OF RECORDS.--March 1988 to current year. GAGE.--Water-stage recorder. Elevation of gage is 98.4 ft (30.0 m), from topographic map. REMARKS.--Records poor. Low flow is affected by discharges from water treatment plant of PRASA and others dispersed pollution points directly to the river. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 10 47 22 20 18 9.2 11 6.6 5.6 6.9 12 9.6 2 9.2 18 337 24 14 9.2 9.8 6.7 8.8 15 5.3 23 3 8.6 14 86 85 15 9.2 12 17 5.7 6.2 7.1 12 4 9.3 39 25 70 14 e9.0 8.0 26 5.4 5.7 39 8.4 5 11 22 229 56 13 9.0 8.0 25 5.2 5.4 12 120 6 24 13 77 68 12 9.1 7.7 11 5.2 5.4 5.3 23 7 40 23 49 71 19 9.1 7.7 14 5.0 14 8.5 10 8 53 213 41 37 13 9.1 7.9 8.9 5.1 5.5 5.1 9.5 9 13 213 28 26 12 9.0 7.1 7.6 5.1 5.4 4.7 7.3 10 9.8 150 21 24 12 9.2 28 8.2 5.2 5.2 4.7 12 11 12 39 19 23 17 9.0 9.2 87 5.6 5.3 4.7 21 12 54 34 17 18 12 8.9 8.7 14 57 5.3 4.8 6.4 13 13 e20 16 41 12 9.0 13 8.8 40 6.0 4.2 6.1 14 9.5 43 16 33 12 9.1 8.1 7.7 59 4.7 5.2 6.3 15 e8.5 116 15 31 11 9.2 7.2 7.8 31 4.5 7.7 6.1 16 e55 48 16 29 11 17 7.7 7.0 16 4.6 16 7.1 17 e56 269 19 20 11 16 7.6 7.2 8.7 8.3 5.3 36 18 e22 95 20 18 22 11 7.0 7.8 6.8 8.5 4.9 26 19 e52 76 17 18 23 9.1 9.1 7.4 6.2 5.2 9.8 24 20 e83 42 16 e19 12 8.5 7.4 7.4 6.0 20 4.9 26 21 e87 28 20 e15 13 e8.4 7.1 6.8 5.9 5.4 4.6 21 22 e26 59 55 14 20 e10 7.5 7.1 5.4 5.2 51 149 23 e42 25 44 14 12 9.1 7.3 7.2 5.5 5.2 646 150 24 e59 88 38 14 11 9.6 7.2 6.5 5.5 5.0 39 38 25 e23 468 33 18 22 9.4 7.2 6.6 6.3 4.9 73 18 26 e17 58 20 14 e13 9.0 7.1 6.3 13 4.8 53 13 27 e14 31 15 14 11 9.3 6.8 8.9 5.8 4.7 70 19 28 12 42 46 13 9.7 19 6.6 13 5.4 6.6 62 13 29 11 29 25 27 9.6 24 7.1 11 5.3 12 17 11 30 20 24 19 15 --- 14 6.9 24 5.2 5.6 12 10 31 125 --- 17 14 --- 26 --- 6.4 --- 5.0 11 --- TOTAL 988.9 2386 1418 903 406.3 345.7 263.0 396.9 355.9 211.5 1209.8 841.8 MEAN 31.9 79.5 45.7 29.1 14.0 11.2 8.77 12.8 11.9 6.82 39.0 28.1 MAX 125 468 337 85 23 26 28 87 59 20 646 150 MIN 8.5 13 15 13 9.6 8.4 6.6 6.3 5.0 4.5 4.2 6.1 AC-FT 1960 4730 2810 1790 806 686 522 787 706 420 2400 1670 CFSM 4.26 10.6 6.11 3.89 1.87 1.49 1.17 1.71 1.58 .91 5.21 3.75 IN. 4.91 11.85 7.04 4.48 2.02 1.72 1.31 1.97 1.77 1.05 6.01 4.18 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1988 - 2000, BY WATER YEAR (WY) MEAN 27.2 27.2 21.2 16.4 13.0 11.4 11.3 14.1 12.4 14.9 22.8 31.5 MAX 57.3 79.5 66.3 29.1 23.6 20.1 23.9 47.2 25.5 38.0 66.9 80.8 (WY) 1991 2000 1999 2000 1991 1999 1993 1992 1999 1993 1992 1998 MIN 8.48 5.93 4.32 6.95 2.70 1.85 2.83 3.38 2.66 4.22 6.60 6.90 (WY) 1992 1996 1996 1995 1996 1996 1995 1994 1994 1994 1990 1991 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1988 - 2000 ANNUAL TOTAL 10414.0 9726.8 ANNUAL MEAN 28.5 26.6 18.5 HIGHEST ANNUAL MEAN 28.6 1999 LOWEST ANNUAL MEAN 7.76 1994 HIGHEST DAILY MEAN 468 Nov 25 646 Aug 23 1650 Sep 10 1996 LOWEST DAILY MEAN 4.8 May 27 4.2 Aug 13 .84 Aug 13 1995 ANNUAL SEVEN-DAY MINIMUM 5.6 Apr 30 4.8 Aug 8 .97 Jun 30 1996 INSTANTANEOUS PEAK FLOW 5220 Nov 25 5390 Sep 10 1996 INSTANTANEOUS PEAK STAGE 15.28 Nov 25 15.46 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 20660 19290 13390 ANNUAL RUNOFF (CFSM) 3.81 3.55 2.47 ANNUAL RUNOFF (INCHES) 51.72 48.31 33.54 10 PERCENT EXCEEDS 60 55 38 50 PERCENT EXCEEDS 15 12 8.2 90 PERCENT EXCEEDS 7.1 5.4 2.8 e Estimated 219 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR--Continued O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 220 RIO PUERTO NUEVO BASIN 50048800 RIO PIEDRAS NEAR RIO PIEDRAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°22'15", long 66°03'40", at bridge on Winston Churchill Avenue in the El Señorial Housing area, 0.5 mi (0.8 km) west of Highway 176, and 2.5 mi (4.0 km) southwest of Río Piedras plaza. DRAINAGE AREA.--8.17 mi2 (20.9 km2). PERIOD OF RECORD.--Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) NOV 29... 1125 31 374 7.3 24.8 39 6.8 81 26 47000 41000 FEB 23... 1430 10 419 7.6 27.5 3.6 6.9 86 10 K14000 5800 APR 20... 1315 5.4 445 7.9 29.1 4.7 5.5 72 13 22000 5300 AUG 16... 1030 4.5 347 7.7 30.1 14 7.2 95 19 K11000 K1500 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) NOV 29... 130 33.6 11.9 23.1 .9 2.5 138 <1.0 16.9 27.4 FEB 23... -- -- -- -- -- -- 148 -- -- -- APR 20... 150 37.8 12.9 29.4 1 2.4 156 -- 13.3 36.3 AUG 16... 110 30.6 9.08 20.1 .8 2.3 118 -- 9.6 25.8 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 29... .1 30.8 229 19.3 8 1.06 .04 1.1 .53 .77 FEB 23... -- -- -- -- 6 .93 .07 1.0 .25 .29 APR 20... .1 35.1 261 3.79 7 .88 .11 1.0 .35 .51 AUG 16... .1 25.5 194 2.38 10 .72 .08 .8 .17 .54 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) NOV 29... 1.3 2.4 10.6 .120 <3 109 56 <.1 <1 <20 FEB 23... .54 1.5 6.8 .140 -- -- -- -- -- -- APR 20... .86 1.9 8.2 .180 E2 103 64 <.1 <1 <20 AUG 16... .71 1.5 6.7 .140 -- -- -- -- -- -- 221 RIO PUERTO NUEVO BASIN 50048800 RIO PIEDRAS NEAR RIO PIEDRAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 29... 520 E1 76 <.3 <3 <1 E18 <.01 <4 .04 FEB 23... -- -- -- -- -- -- -- -- -- -- APR 20... 330 <1 118 <.3 <3 <1 <31 <.01 E9 .07 AUG 16... -- -- -- -- -- -- -- -- -- -- CHLOR- DANE, P,P'- P,P'- ENDO- TECH- DDD P,P'- DDT DI- DI- SULFAN PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I DATE TOTAL TOTAL TOTAL RECOVER TOTAL RECOVER TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39516) (39330) (39350) (39360) (39365) (39370) (39570) (39380) (39388) NOV 29... -- -- -- -- -- -- -- -- -- FEB 23... -- -- -- -- -- -- -- -- -- APR 20... <.1 <.013 <.1 <.014 <.016 <.017 E.02 <.009 <.015 AUG 16... -- -- -- -- -- -- -- -- -- ENDRIN HEPTA- METH- METHYL WATER HEPTA- CHLOR MALA- OXY- PARA- UNFLTRD ETHION, CHLOR, EPOXIDE LINDANE THION, CHLOR, THION, MIREX, DATE REC TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39390) (39398) (39410) (39420) (39340) (39530) (39480) (39600) (39755) NOV 29... -- -- -- -- -- -- -- -- -- FEB 23... -- -- -- -- -- -- -- -- -- APR 20... <.014 <.01 <.011 <.009 <.012 <.03 <.01 <.01 <.01 AUG 16... -- -- -- -- -- -- -- -- -- CARBO- PHENO- PCNS PARA- PER- TOX- THION UNFILT THION, THANE APHENE, WATER 2,4-D, 2,4,5-T 2,4-DP SILVEX, DATE RECOVER TOTAL TOTAL TOTAL UNFLTRD TOTAL TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39250) (39540) (39034) (39400) (39786) (39730) (39740) (82183) (39760) NOV 29... -- -- -- -- -- -- -- -- -- FEB 23... -- -- -- -- -- -- -- -- -- APR 20... <.1 <.01 <.1 <1 <.01 <.05 <.03 <.04 <.03 AUG 16... -- -- -- -- -- -- -- -- -- 222 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR LOCATION.--Lat 18°24'34", long 66°04'10", Hydrologic Unit 21010005, at bridge on Avenida Piñeiro near Expreso Las Américas(Luis A. Ferré), and 0.8 mi (1.3 km) southwest of Hato Rey. DRAINAGE AREA.--15.2 mi2 (39.4 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--June 1970 to December 1987 (discharge measurements only), 1972 to December 1982 (maximum discharge only), January 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 16 ft (5 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Mean daily discharge affected by sewage discharges (approximately 2.0 ft3/s (0.06 m3/s)), 20 ft (6 m) upstream from gaging station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e22 e38 38 44 e38 19 23 18 13 26 28 31 2 e30 e31 541 44 e28 19 21 17 21 28 15 55 3 e20 e29 159 e146 e29 20 27 105 13 17 16 86 4 e22 e39 e51 144 e29 19 19 45 12 14 106 31 5 e21 e33 e309 92 e27 19 18 72 12 14 32 241 6 e28 e30 133 95 e25 19 18 29 12 13 15 43 7 47 e32 99 132 e33 19 17 39 12 19 22 31 8 45 e77 68 67 e23 18 21 33 12 14 15 30 9 e26 e96 49 49 e23 17 16 27 11 13 14 27 10 e22 e95 42 45 e24 18 28 23 11 13 21 179 11 e29 96 39 42 e40 18 18 406 11 12 13 47 12 e51 e78 37 38 e26 20 21 30 77 13 14 28 13 e26 e47 35 e63 e26 20 41 20 54 22 13 27 14 e22 e75 34 e61 e28 21 23 18 53 14 16 27 15 e22 e126 33 e50 e25 e21 20 17 29 11 54 27 16 e52 79 33 e55 e25 e23 26 16 26 11 29 25 17 e119 376 40 42 e25 e38 21 16 18 20 16 93 18 43 147 39 41 e60 e25 20 19 15 19 15 39 19 87 120 38 37 e61 e20 21 15 15 12 24 55 20 187 84 37 37 e28 e19 19 17 14 51 15 39 21 235 e65 48 32 e30 e22 18 15 14 15 15 38 22 54 e98 83 30 e52 e24 20 18 14 14 63 247 23 70 e56 100 31 e26 18 19 16 13 21 1740 251 24 85 e132 75 30 23 19 18 19 13 14 71 44 25 38 492 56 e37 32 19 18 16 16 14 255 43 26 30 116 50 e31 25 18 18 13 43 14 126 31 27 28 39 34 e30 27 19 17 14 16 15 78 35 28 e27 41 111 e28 21 40 18 31 14 14 89 27 29 e28 35 58 e77 20 71 20 22 13 37 37 26 30 e30 51 56 31 --- 117 20 36 14 16 35 25 31 e58 --- 62 e28 --- 29 --- 13 --- 14 33 --- TOTAL 1604 2853 2587 1709 879 808 624 1195 611 544 3035 1928 MEAN 51.7 95.1 83.5 55.1 30.3 26.1 20.8 38.5 20.4 17.5 97.9 64.3 MAX 235 492 541 146 61 117 41 406 77 51 1740 251 MIN 20 29 33 28 20 17 16 13 11 11 13 25 AC-FT 3180 5660 5130 3390 1740 1600 1240 2370 1210 1080 6020 3820 CFSM 3.40 6.26 5.49 3.63 1.99 1.71 1.37 2.54 1.34 1.15 6.44 4.23 IN. 3.93 6.98 6.33 4.18 2.15 1.98 1.53 2.92 1.50 1.33 7.43 4.72 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1972 - 2000, BY WATER YEAR (WY) MEAN 72.4 75.8 55.1 46.2 41.6 36.7 49.4 43.1 40.6 46.8 59.5 95.3 MAX 156 235 168 97.4 86.9 78.5 150 97.5 81.9 97.4 97.8 261 (WY) 1999 1993 1993 1993 1995 1972 1972 1992 1995 1993 2000 1996 MIN 16.6 23.9 18.8 12.9 10.8 11.5 13.6 4.12 20.0 12.8 20.2 26.3 (WY) 1992 1991 1992 1973 1992 1994 1995 1972 1994 1994 1993 1972 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1972 - 2000 ANNUAL TOTAL 17607 18377 ANNUAL MEAN 48.2 50.2 54.5 HIGHEST ANNUAL MEAN 84.0 1993 LOWEST ANNUAL MEAN 28.7 1994 HIGHEST DAILY MEAN 541 Dec 2 1740 Aug 23 4550 Sep 10 1996 LOWEST DAILY MEAN 13 May 2 11 Jun 9 1.2 Jun 28 1972 ANNUAL SEVEN-DAY MINIMUM 14 Apr 28 12 Jun 5 1.2 Jul 5 1972 INSTANTANEOUS PEAK FLOW 6410 Aug 23 10500 Sep 10 1996 INSTANTANEOUS PEAK STAGE 18.35 Aug 23 22.11 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 34920 36450 39500 ANNUAL RUNOFF (CFSM) 3.17 3.30 3.59 ANNUAL RUNOFF (INCHES) 43.09 44.98 48.74 10 PERCENT EXCEEDS 99 94 119 50 PERCENT EXCEEDS 30 28 23 90 PERCENT EXCEEDS 17 14 10 e Estimated 223 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 224 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'34", long 66°04'10", at bridge on Avenida Piniero at Expreso Las Americas, and 0.8 mi (1.3 km) southwest of Hato Rey. DRAINAGE AREA.--15.4 mi2 (39.9 km2). PERIOD OF RECORD.--Water years 1971 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) NOV 26... 1300 65 368 7.8 25.9 91 6.9 84 30 46000 26000 FEB 23... 1130 25 251 7.7 25.8 59 8.0 97 11 39000 71000 APR 25... 1100 18 477 8.0 28.2 32 7.1 90 14 58000 6700 AUG 15... 1015 15 447 7.6 28.2 2.0 3.8 49 30 61000 39000 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) NOV 26... 140 38.6 10.6 21.4 .8 2.7 136 <1.0 19.0 23.3 FEB 23... -- -- -- -- -- -- 161 -- -- -- APR 25... 160 44.3 12.1 31.3 1 2.8 175 <1.0 12.9 38.2 AUG 15... 150 41.0 10.5 28.1 1 3.1 154 -- 12.6 34.8 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 26... .1 23.5 221 38.9 154 1.24 .06 1.3 .44 .76 FEB 23... -- -- -- -- 99 .88 .09 1.0 .77 .63 APR 25... .2 35.1 282 13.4 47 1.16 .14 1.3 .74 .36 AUG 15... .2 29.6 252 10.0 <10 .44 .09 .5 2.30 .60 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) NOV 26... 1.2 2.5 11.1 .130 E2 166 47 .1 5 E14 FEB 23... 1.4 2.4 10.5 .270 -- -- -- -- -- -- APR 25... 1.1 2.4 10.6 .240 <3 109 58 <.1 2 <20 AUG 15... 2.9 3.4 15.2 .390 -- -- -- -- -- -- 225 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 26... 4930 6 264 <.3 <3 <1 37 <.01 6 <.04 FEB 23... -- -- -- -- -- -- -- -- -- -- APR 25... 1620 2 139 <.3 <3 3 E18 <.01 E4 .06 AUG 15... -- -- -- -- -- -- -- -- -- -- 226 RIO PUERTO NUEVO BASIN 50049820 LAGUNA SAN JOSE NO. 2 AT SAN JUAN, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°25'46", long 66°02'10", 0.2 mi (0.3 km) east of Caño de Martín Peña, and 650 ft (200 m) south of Isla Guachinango. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 PH OXYGEN, COLI- SPE- WATER TRANS- DIS- FORM, STREP- CIFIC WHOLE PAR- SOLVED FECAL, TOCOCCI CON- FIELD TEMPER- ENCY OXYGEN, (PER- 0.45 FECAL, DUCT- (STAND- ATURE (SECCHI DIS- CENT UM-MF (COLS. DATE TIME ANCE ARD WATER DISK) SOLVED SATUR- (COLS./ PER (US/CM) UNITS) (DEG C) (IN) (MG/L) ATION) 100 ML) 100 ML) (00095) (00400) (00010) (00077) (00300) (00301) (31616) (31679) OCT 1999 14... 1040 17400 7.4 28.6 42.0 3.3 45 K9100 230 DEC 13... 0900 6180 7.9 24.2 30.0 8.1 99 >600 >530 MAR 2000 03... 0900 2130 8.0 25.2 26.0 4.6 56 48 K150 MAY 10... 0930 29500 7.1 28.5 54.0 1.3 19 K820 K40 SEP 12... 1050 18600 7.4 30.8 64.0 2.2 31 4100 K70 ANC RESIDUE NITRO- WATER TOTAL NITRO- NITRO- GEN,AM- NITRO- UNFLTRD AT 105 GEN, GEN, MONIA + GEN, PHOS- CARBON, FET DEG. C, AMMONIA NITRITE ORGANIC NO2+NO3 PHORUS ORGANIC FIELD SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE MG/L AS PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L CACO3 (MG/L) AS N) AS N) AS N) AS N) AS P) AS C) (00410) (00530) (00610) (00615) (00625) (00630) (00665) (00680) OCT 1999 14... 75 23 .54 <.01 1.2 <.1 .180 5.8 DEC 13... 82 16 .30 .09 .92 .2 .090 6.1 MAR 2000 03... 100 17 .29 .02 1.8 <.1 .260 12 MAY 10... 75 18 .67 .01 1.3 <.1 .240 8.1 SEP 12... 82 14 .91 .02 1.8 .1 .210 6.2 227 RIO PUERTO NUEVO BASIN 50049920 BAHIA DE SAN JUAN NO.5 AT SAN JUAN, PR WATER-QUALITY RECORDS LOCATION--Lat 18°26'37", long 66°05'11", 0.4 mi (0.6 km) west of Puente de la Constitucion, and 0.5 mi (0.8 km) south from U.S. Naval Reservation. DRAINAGE--Indeterminate. PERIOD OF RECORD--Water years 1974 to present. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 PH OXYGEN, COLI- SPE- WATER TRANS- DIS- FORM, STREP- CIFIC WHOLE PAR- SOLVED FECAL, TOCOCCI CON- FIELD TEMPER- ENCY OXYGEN, (PER- 0.45 FECAL, DUCT- (STAND- ATURE (SECCHI DIS- CENT UM-MF (COLS. DATE TIME ANCE ARD WATER DISK) SOLVED SATUR- (COLS./ PER (US/CM) UNITS) (DEG C) (IN) (MG/L) ATION) 100 ML) 100 ML) (00095) (00400) (00010) (00077) (00300) (00301) (31616) (31679) OCT 14... 1140 54000 7.8 30.1 36.0 4.6 74 >6000 5800 DEC 13... 1000 52400 7.5 26.4 54.0 5.3 81 >240 >400 MAR 03... 1030 5260 8.2 26.0 44.0 4.6 58 K1800 31 MAY 10... 1030 53900 7.8 27.3 27.0 4.6 71 K18000 600 SEP 12... 1150 49500 8.0 30.2 36.0 4.2 68 20000 650 ANC RESIDUE NITRO- WATER TOTAL NITRO- NITRO- GEN,AM- NITRO- UNFLTRD AT 105 GEN, GEN, MONIA + GEN, PHOS- CARBON, FET DEG. C, AMMONIA NITRITE ORGANIC NO2+NO3 PHORUS ORGANIC FIELD SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE MG/L AS PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L CACO3 (MG/L) AS N) AS N) AS N) AS N) AS P) AS C) (00410) (00530) (00610) (00615) (00625) (00630) (00665) (00680) OCT 14... 133 61 1.60 .06 1.2 .1 .160 4.1 DEC 13... 167 41 1.20 .09 1.5 .5 .200 4.4 MAR 03... 146 25 .56 .05 1.0 .2 .200 7.1 MAY 10... 126 28 .46 .02 .62 .1 .110 2.7 SEP 12... 118 32 .44 .02 .78 .1 .120 3.0 THIS PAGE IS INTENTIONALLY BLANK 228 18°27 30
 18°15
66°05
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 Río Río Río Río Río Río Río Río Río Río Río Río Río Grande Grande Gurabo Grande C a y a g u á s de de Cañas Lago Loíza Laguna San José Bahía de San Juan Laguna La Torrecilla Laguna de Piñones Quebrada de las Qubrada Quebradillas Qubrada Qubrada Qubrada Quebrada Arenas Bairoa Turabo Gurabo Turabo Caguitas Loíza Loíza Canóvanas Canóvanillas Maracuto P a st r a n a Blasina Caño de Martín Peña Valenciano 0509 059050 QUALITY-OF-WATER STATION AND NUMBER 0590 0503 222 EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SEDIMENT STATION AND NUMBER SURFACE-WATER STATION AND NUMBER Figure 18. Río Grande de Loíza basin. 229 CATAÑO SAN JUAN ATLANTIC OCEAN CAROLINA LOÍZA RÍO GRANDE HUMACAO SAN LORENZO LAS PIEDRAS TRUJILLO ALTO JUNCOS CAGUAS GURABO AGUAS BUENAS CANÓVANAS Basin area PUERTO RICO 0 0 1 1 2 2 3 3 4 4 5 MILES 5 KILOMETERS 0509 051310 051150 053025 051180 051800 0564 055750 0570 057025 0550 0618 059050 058350 0551 0554 055390 055225 055250 0575 0588 0591 0590 0503 222 1176 1179 1180 1181 50 1177 1178 230 RIO GRANDE DE LOIZA BASIN 50050300 QUEBRADA BLASINA NEAR CAROLINA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°23'27", long 65°58'28", at bridge on Highway 3, 1.4 mi (2.3 km) south of Valle Arriba Heights housing area, and 1.2 mi (1.9 km) west-southwest of Carolina plaza. DRAINAGE AREA.--2.96 mi2 (7.67 km2). PERIOD OF RECORD.--Water years 1973 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DIS- PH OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- WATER DIS- DEMAND, FORM, TOCOCCI INST. CIFIC WHOLE SOLVED CHEM- FECAL, FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) DEC 03... 1335 26 479 7.3 25.5 6.0 5.4 65 17 34000 7900 FEB 14... 1325 9.9 484 7.8 27.4 25 4.0 50 20 21000 960 MAY 01... 1330 5.9 509 8.0 27.4 .5 5.4 68 12 K3000 750 SEP 07... 1045 5.1 473 7.9 27.8 66 6.1 77 13 5800 2300 ANC HARD- MAGNE- SODIUM POTAS- WATER CHLO- NESS CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, TOTAL DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- (MG/L SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) (00900) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) DEC 03... 180 54.5 9.85 27.0 .9 3.4 169 <1.0 24.0 29.6 FEB 14... -- -- -- -- -- -- 175 -- -- -- MAY 01... 180 52.2 12.1 33.4 1 2.6 167 <1.0 15.7 42.4 SEP 07... 170 55.0 8.49 22.2 .7 2.9 175 -- 10.9 35.9 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) DEC 03... .1 19.0 269 18.5 16 1.23 .07 1.3 1.00 .90 FEB 14... -- -- -- -- 6 1.11 .09 1.2 .38 .40 MAY 01... .2 29.1 288 4.61 <10 .87 .13 1.0 .38 .08 SEP 07... .1 24.8 265 3.66 119 1.14 .16 1.3 .53 .47 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) DEC 03... 1.9 3.2 14.2 .180 3 81.4 58 <.1 <1 <20 FEB 14... .78 2.0 8.8 .190 -- -- -- -- -- -- MAY 01... .46 1.5 6.5 .170 E1 57.7 56 <.1 <1 <20 SEP 07... 1.0 2.3 10.2 .170 -- -- -- -- -- -- 231 RIO GRANDE DE LOIZA BASIN 50050300 QUEBRADA BLASINA NEAR CAROLINA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) DEC 03... 450 E1 185 <.3 E2 <1 E22 <.01 8 .20 FEB 14... -- -- -- -- -- -- -- -- -- -- MAY 01... 180 <1 94 <.3 <3 <1 <31 <.01 <4 .03 SEP 07... -- -- -- -- -- -- -- -- -- -- 232 RIO GRANDE DE LOIZA BASIN 50050900 RIO GRANDE DE LOIZA AT QUEBRADA ARENAS, PR LOCATION.--Lat 18°07'10", long 65°59'22", Hydrologic Unit 21010005, at intersection of Highways 181 and 9990, 0.2 mi (0.3 km) upstream from confluence with Río Emajagua and about 7.1 mi (11.4 km) southwest of San Lorenzo. DRAINAGE AREA.--6.00 mi2 (15.54 km2). PERIOD OF RECORD.--October 1977 to current year. GAGE.--Water-stage recorder. Elevation of gage is 640 ft (195 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 32 56 27 17 13 9.2 6.0 6.5 17 8.7 8.9 16 2 21 18 26 16 12 8.6 5.9 6.1 15 17 8.2 15 3 18 28 26 28 12 8.4 5.9 5.9 13 18 11 15 4 25 20 22 20 12 8.1 5.9 5.9 14 11 23 13 5 18 29 112 40 11 7.9 6.5 11 11 9.2 19 13 6 22 59 46 71 11 7.7 6.1 8.6 10 8.6 11 13 7 18 24 28 37 12 7.8 5.9 9.0 9.9 8.1 14 30 8 23 20 24 21 11 7.6 6.0 8.7 9.7 9.7 37 15 9 20 29 22 17 10 7.4 5.7 6.4 9.2 8.2 13 13 10 16 532 21 16 11 7.3 5.8 8.6 9.3 7.8 24 103 11 15 177 20 15 10 7.0 5.6 634 9.3 7.9 13 315 12 28 266 19 14 9.8 7.1 5.7 34 187 26 9.9 21 13 35 506 18 14 11 7.2 6.0 14 25 13 8.9 16 14 20 80 18 13 12 7.0 8.6 11 14 28 8.6 15 15 16 97 17 13 10 6.9 6.4 9.4 12 12 9.2 14 16 15 85 17 14 9.7 6.9 10 8.6 29 9.4 13 29 17 15 615 17 12 9.5 7.0 7.6 247 16 9.9 12 111 18 15 273 18 12 9.7 6.6 6.7 182 13 17 8.7 248 19 14 127 32 12 12 6.5 22 27 11 12 8.1 46 20 30 82 29 12 10 6.4 20 17 10 11 7.7 30 21 23 59 19 12 9.3 6.4 7.5 21 10 9.2 7.5 43 22 16 49 20 12 11 6.3 6.5 12 9.6 8.5 18 23 23 14 42 18 12 10 6.2 7.6 11 9.1 8.3 979 44 24 13 38 17 12 30 6.7 12 9.9 8.9 8.0 e24 22 25 119 35 16 14 25 6.2 7.5 12 10 7.7 e30 20 26 26 32 15 18 11 6.1 6.7 11 13 7.5 e45 17 27 18 30 15 13 9.8 6.0 6.4 11 11 7.4 e27 159 28 16 28 18 12 9.2 8.2 6.1 22 8.9 7.3 e28 175 29 17 27 107 13 9.4 9.0 6.5 17 8.5 36 19 31 30 15 26 20 12 --- 6.8 7.0 336 8.3 16 17 23 31 19 --- 19 11 --- 6.2 --- 24 --- 9.8 e33 --- TOTAL 712 3489 843 555 343.4 222.7 232.1 1747.6 541.7 378.2 1495.7 1648 MEAN 23.0 116 27.2 17.9 11.8 7.18 7.74 56.4 18.1 12.2 48.2 54.9 MAX 119 615 112 71 30 9.2 22 634 187 36 979 315 MIN 13 18 15 11 9.2 6.0 5.6 5.9 8.3 7.3 7.5 13 AC-FT 1410 6920 1670 1100 681 442 460 3470 1070 750 2970 3270 CFSM 3.83 19.4 4.53 2.98 1.97 1.20 1.29 9.40 3.01 2.03 8.04 9.16 IN. 4.41 21.63 5.23 3.44 2.13 1.38 1.44 10.84 3.36 2.34 9.27 10.22 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1978 - 2000, BY WATER YEAR (WY) MEAN 42.1 46.7 26.2 21.5 19.0 15.2 14.1 30.0 35.8 35.1 34.8 60.4 MAX 123 122 59.5 56.1 38.0 53.6 31.5 77.5 122 92.3 90.0 351 (WY) 1986 1988 1999 1992 1982 1998 1998 1985 1979 1993 1979 1998 MIN 13.1 8.34 6.65 8.16 6.36 5.07 4.64 7.20 11.3 12.2 9.30 11.8 (WY) 1990 1990 1990 1990 1979 1979 1979 1999 1985 2000 1991 1981 SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1978 - 2000 ANNUAL TOTAL 10669.7 12208.4 ANNUAL MEAN 29.2 33.4 31.7 HIGHEST ANNUAL MEAN 62.7 1998 LOWEST ANNUAL MEAN 14.5 1990 HIGHEST DAILY MEAN 615 Nov 17 979 Aug 23 4690 Sep 22 1998 LOWEST DAILY MEAN 5.2 May 2 5.6 Apr 11 3.1 May 7 1979 ANNUAL SEVEN-DAY MINIMUM 5.4 Apr 30 5.8 Apr 7 3.6 May 1 1979 INSTANTANEOUS PEAK FLOW 7170 Aug 23 45000 Sep 21 1998 INSTANTANEOUS PEAK STAGE 12.35 Aug 23 26.37 Sep 21 1998 INSTANTANEOUS LOW FLOW 5.2 Apr 11 2.8 May 5 1979 ANNUAL RUNOFF (AC-FT) 21160 24220 23000 ANNUAL RUNOFF (CFSM) 4.87 5.56 5.29 ANNUAL RUNOFF (INCHES) 66.15 75.69 71.90 10 PERCENT EXCEEDS 41 42 50 50 PERCENT EXCEEDS 15 13 15 90 PERCENT EXCEEDS 6.4 6.8 7.1 e Estimated 233 RIO GRANDE DE LOIZA BASIN 50050900 RIO GRANDE DE LOIZA AT QUEBRADA ARENAS, PR--Continued O N D 1999 J F M A M J J A S 2000 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 234 RIO GRANDE DE LOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR LOCATION.--Lat 18°09'40", long 65°58'58", Hydrologic Unit 2l0l0005,0.1 mi (0.2 km) upstream from bridge on Highway 181,and 2.8 mi (4.5 km) southwest of San Lorenzo. DRAINAGE AREA.--3.25 mi2 (8.42 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1984 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 459 ft (140 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 5.5 10 5.5 4.7 5.4 4.1 1.5 1.4 4.7 2.2 5.1 4.6 2 4.1 3.9 16 4.3 3.1 3.0 1.5 1.3 3.2 2.6 3.1 5.1 3 3.4 3.6 14 4.9 2.9 2.8 1.4 1.8 2.6 2.3 2.5 4.4 4 7.8 3.2 e7.2 4.2 3.3 2.6 1.4 1.4 4.3 2.0 6.0 3.3 5 3.7 4.1 e27 8.9 2.8 2.5 1.3 3.9 2.4 1.7 6.3 3.1 6 3.6 12 e19 10 2.5 2.4 1.3 2.8 1.9 1.6 2.9 3.4 7 3.0 4.9 e14 9.3 2.6 2.4 1.2 1.9 1.7 1.7 2.8 2.8 8 10 3.3 e11 6.0 2.5 2.3 1.3 1.6 1.6 1.8 5.2 2.5 9 13 4.9 e8.9 4.9 2.4 2.2 1.2 1.4 1.5 1.7 3.4 2.3 10 5.3 72 e7.7 4.4 2.4 2.1 1.2 1.4 1.4 1.7 2.8 6.9 11 4.1 26 e6.8 4.0 2.4 2.1 1.2 43 1.4 1.6 2.4 18 12 5.4 26 e6.1 3.7 2.2 2.1 1.2 13 38 2.5 2.2 4.7 13 4.8 e22 e5.6 3.5 2.5 2.1 1.7 5.0 17 2.1 2.0 3.4 14 4.0 14 e5.2 5.2 2.4 2.0 2.1 3.0 7.0 3.8 1.9 2.6 15 3.4 16 4.9 4.2 2.2 2.0 1.6 2.3 6.1 2.5 2.4 2.3 16 3.0 18 4.8 4.5 2.1 1.9 1.5 2.0 14 2.0 4.2 2.1 17 3.3 67 4.7 3.4 2.1 1.9 1.6 4.5 8.2 1.9 2.4 4.6 18 3.3 60 4.6 3.2 2.3 2.0 1.5 10 5.1 2.5 2.0 18 19 7.4 35 6.2 3.0 3.0 1.9 4.2 4.8 3.9 2.7 1.9 14 20 11 23 6.6 2.9 2.4 1.8 2.0 2.8 3.1 2.4 1.9 11 21 19 16 4.9 2.8 2.1 1.7 1.6 2.4 2.8 2.0 1.8 15