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Water Resources Data Puerto Rico and the U.S. Virgin Islands Water Year 1995 St Thomas I Isla de \P Culebra Isla de Vieques PUERTO RICO St John I U. S. V I R G I N ISLANDS Saint Croix I U.S. GEOLOGICAL SURVEY WATER-DATA REPORT PR-95-1 Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands and other agencies CALENDAR FOR WATER YEAR 1995 1994 OCTOBER S M T W T F S 1 2345678 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 NOVEMBER 5 M T W T F S 12345 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 DECEMBER S M T W T F S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1995 JANUARY S M T W T F S 1234567 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 APRIL S M T W T F S 1 2345678 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 JULY S M T W T F S I 2345678 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 FEBRUARY S M T W T F S 1234 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 MAY S M T W T F S 123456 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 AUGUST 5 M T W T F S 12345 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MARCH S M T W T F S 1234 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 JUNE S M T W T F S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 SEPTEMBER S M T W T F S 1 2 3456789 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Water Resources Data Puerto Rico and the U.S. Virgin Islands Water Year 1995 by P.L. Diaz, Z. Aquino, C. Figueroa-Alamo, R.J. Vachier, and A.V. Sanchez St Thomas deV Isla Culebra Isla de Vieques PUERTO RICO St John U. S. V I R G I N ISLANDS Saint Croix U.S. GEOLOGICAL SURVEY WATER-DATA REPORT PR-95-1 Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands and other agencies U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Gordon P. Eaton, 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) 1996 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 Geological Survey policy and established guidelines, the following personnel contributed significantly to the collection, processing and tabulations of the data: Jose M. Agis Rafael Pena-Cortez George Arroyo Carlos C. Rodriguez Angel Class-Cacho Julio A. Rodriguez Iris M. Conception Miguel Rodriguez Israel Cruz Jose Rene Sdnchez Angel G. Ferrer Luis Santiago-Rivera Pedro Galindo Luis Soler Evelyn S. Guevara Heriberto Torres-Sierra Senen Guzman-Rios James Torres Sandra Lagares Jose A. Torres Carlos Narvaez Ahmed Valencia Ruth I. Guzman typed the text of the report. Francisco Maldonado prepared the illustrations. 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 Rafael W. Rodriguez, District Chief, Caribbean District, San Juan, Puerto Rico. REPORT DOCUMENTATION PAGE Form Approved OMBNo. 0704-0188 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. 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED May 24, 1996 Annual - October 1, 1994 to September 30, 1995 4. TITLE AND SUBTITLE Water Resources Data for Puerto Rico and the U.S. Virgin Islands Water Year 1995 6. AUTHOR(S) Pedro L. Diaz, Zaida Aquino, Carlos Figueroa- Alamo, Ricardo J. Vachier, Ana V. Sanchez 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Geological Survey, Water Resources Division GSA Center, 651 Federal Drive, Suite 400-15 Guaynabo, Puerto Rico 00965 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) U.S. Geological Survey, Water Resources Division GSA Center, 651 Federal Drive, Suite 400-15 Guaynabo, Puerto Rico 00965 5. FUNDING NUMBERS 8. PERFORMING ORGANIZATION REPORT NUMBER USGS-WDR-PR-95-1 10. SPONSORING / MONITORING AGENCY REPORT NUMBER USGS-WDR-PR-95-1 11. SUPPLEMENTARY NOTES Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and other agencies. 12a. DISTRIBUTION /AVAILABILITY STATEMENT NO RESTRICTION ON DISTRIBUTIONS 12b. DISTRIBUTION CODE 13. ABSTRACT (Maximum 200 words) Water resources data for surface-water, quality-of- water, and ground-water records for the 1995 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 74 streamflow-gaging stations; stage only for 5 gaging stations, daily sediment records for 23 streamflow stations; 94 partial-record or miscellaneous streamflow stations; stage records for 14 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 65 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. 14. SUBJECT TERMS *Surface water, *Water quality, *Ground water, Aquifers, Chemical analysis, Gz stations, Hydrologic data Sediments, Streamflow, Water analysis, Water levels, L 15. NUMBER OF PAGES 552 Lging 16. PRICE CODE akes 17. SECURITY CLASSIFICATION 16. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACT OF REPORT OF THIS PAGE OF ABSTRACT Unclassified Unclassified NSN 7540-01-280-5500 Standard Form 296 (Rev. 2-89) Prescribed by ANSI Std 239-18 293-102 CONTENTS v 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 ............................................................. xii 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 ..................................................................... 8 Special networks and programs ............................................................. 9 Explanation of records ................................................................... 9 Station identification numbers .......................................................... 10 Downstream order system ......................................................... 10 Latitude-longitude system ......................................................... 10 Records of stage and water discharge ..................................................... 20 Data collection and computation .................................................. 20 Data Presentation ............................................................ 21 Station manuscript .......................................................... 21 Data table of daily mean values ................................................. 22 Statistics of monthly mean data ................................................. 23 Summary statistics .......................................................... 23 Identifying estimated daily discharge ................................................. 24 Accuracy of the records .......................................................... 24 Records of surface-water quality ........................................................ 25 Classification of records .......................................................... 25 Arrangement of records .......................................................... 25 On-site measurements and sample collection ............................................ 25 Water temperature .............................................................. 26 Sediment .................................................................... 26 Laboratory measurements ......................................................... 26 Data presentation ............................................................... 27 Remark codes ................................................................. 28 Records of ground-water levels ......................................................... 28 Data collection and computation .................................................... 28 Data presentation ............................................................... 29 Records of ground-water quality ........................................................ 29 Data collection and computation .................................................... 30 Data presentation ............................................................... 30 Access to WATSTORE data ............................................................... 30 Definition of terms ...................................................................... 31 Publications on Techniques of Water-Resources Investigations ....................................... 41 Surface- and quality-of-water records for Puerto Rico ............................................. 45 Discharge at partial-record stations in Puerto Rico ............................................... 417 Water-quality at partial-record stations in Puerto Rico ............................................ 429 Ground-water records for Puerto Rico ....................................................... 445 Surface-water records for the U.S. Virgin Islands ............................................... 513 Ground-water records for the U.S. Virgin Islands ............................................... 521 Index .............................................................................. 528 VI ILLUSTRATIONS Page Figure 1. Graph showing monthly-mean discharge of selected streams in Puerto Rico ...................... 4 2. Graph showing ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands ............................................................... 7 3. Map showing location of fecal coliform bacteria concentration at sampled sites .................. 11 4. Map showing location of fecal streptococci bacteria concentration at sampled sites ................ 12 5. Map showing location of surface-water stations in Puerto Rico .............................. 13 6. Map showing location of water-quality stations in Puerto Rico .............................. 14 7. Map showing location of low-flow partial-record stations in North-central Puerto Rico ............. 15 8. Map showing location of ground-water stations in Puerto Rico .............................. 16 9. Map showing location of surface-water stations in U.S. Virgin Islands ........................ 17 10. Map showing location of ground-water stations in the U.S. Virgin Islands ..................... 18 11. Map showing location of surface-water stations in Vieques Island ........................... 19 12. Grid showing system for numbering wells and miscellaneous site (latitude and longitude) .......... 20 13. Map showing the Rio Guajataca basin .............................................. 47 14. Map showing the Rfo Camuy basin ................................................ 57 15. Map showing the Rio Grande de Arecibo basin ........................................ 61 16. Map showing the Rio Grande de Manati basin ......................................... 87 17. Map showing the Rio Cibuco basin ............................................... 107 18. Map showing the Rio de la Plata basin ............................................. 115 19. Map showing the Rio Hondo to the Rio Puerto Nuevo basins ............................. 149 20. Map showing the Rio Grande de Loiza basin ......................................... 181 21. Map showing northeastern river basins the Rio Herrera to the Rio Anton Ruiz basins ............ 297 22. Map showing southeastern river basins the Rio Humacao to the Rio Seco basins ................ 327 23. Map showing south coast river basins the Rio Salinas to the Rio Jacaguas basins ............... 345 24. Map showing south coast river basins the Rio Inabon to the Rio Loco basins .................. 360 25. Map showing the Rio Guanajibo basin ............................................. 381 26. Map showing the Rio Yagiiez and the Rio Grande de Anasco basins ........................ 397 27. Map showing the Rio Culebrinas basin ............................................. 409 TABLES Page Table 1. Island-wide monthly precipitation and annual averages for 1995 water year and the 30-year reference period, 1961-90 .............................................. 3 2. Summary of discharges at streamflow gaging stations where the previous maximum discharge was exceeded in the U.S. Virgin Islands during September 15, 1995 ................. 5 3. Highest water level recorded during 1995 water year and previous high water level (in feet below land-surface datum) at selected ground-water wells in Puerto Rico and the U.S. Virgin Islands ............................................ 6 4. Surface-water quality stations in Puerto Rico with highest concentration of selected constituents during water year 1995 ......................................... 8 5. Factors for conversion of chemical constituents in milligrams per liter to milli- equivalents per liter .......................................................... 35 SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, VII 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 Rio Guajataca at Lares (d,c,b) .......................................... 50010500 48 Lago Guajataca at Damsite near Quebradillas (e) ............................. 50010800 51 Canal Principal de Diversiones at Lago Guajataca (c,b) ........................ 50011000 52 Rio Guajataca above mouth near Quebradillas (c,b) ........................... 50011400 54 RIO CAMUY BASIN Rio Camuy at Tres Pueblos Sinkhole (d) ................................... 50014600 58 Rio Camuy near Bayaney (d) ........................................... 50014800 59 Rio Camuy near Hatillo (d) ............................................ 50015700 60 RIO GRANDE DE ARECIBO BASIN Lago Garzas near Adjuntas (e) ...................................... 50020100 62 Rio Grande de Arecibo near Adjuntas (c,b) ................................. 50020500 63 Rio Grande de Arecibo near Utuado (c,b) .................................. 50025000 65 Rio Saliente at Coabey near Jayuya (d) ................................ 50025155 67 Rio Caonillas above Lago Caonillas near Jayuya (c,b) ............................. 50026050 68 Lago Caonillas at Damsite near Utuado (e) .............................. 50026140 70 Rfo Grande de Arecibo below Lago Dos Bocas near Florida (c,b) ................. 50027250 71 Rio Grande de Arecibo above Arecibo (d) .................................. 50027750 73 Rio Tanama" near Utuado (d,c,b,s) .................................... 50028000 74 Rio Tanama" at Charco Hondo (d) .................................... 50028400 83 Rfo Grande de Arecibo at Central Cambalache (c,b) ........................... 50029000 84 RIO GRANDE DE MANATI BASIN Rio Orocovis at Orocovis (d) ........................................ 50030460 88 Rio Orocovis near Orocovis (c,b) ..................................... 50030700 89 Rio Grande de Manatf near Morovis (d,c,b) ................................. 50031200 91 Lago El Guineo at Damsite near Villalba (e) ............................. 50032290 94 Lago de Matrullas at Damsite near Orocovis (e) .......................... 50032590 95 Rio Bauta near Orocovis (d) ........................................ 50034000 96 Rfo Grande de Manatf at Ciales (d) ....................................... 50035000 97 Rfo Grande de Manatf at Highway 149 at Ciales (c,b) ......................... . '50035500 98 Rfo Cialitos at Highway 649 at Ciales (c,b) ............................. 50035950 100 Rfo Grande de Manatf at Highway 2 near Manatf (d,c,b,p) ...................... 50038100 102 LACUNA TORTUGUERO BASIN Laguna Tortuguero Outlet near Vega Baja (c,b) .............................. 50038200 105 RIO CIBUCO BASIN Rfo Cibuco below Corozal (d,c,b) ........................................ 50038320 108 Rfo Cibuco at Vega Baja (d,c,b) ......................................... 50039500 111 RIO DE LA PLATA BASIN Lago Carite at Gate Tower near Cayey (e) .................................. 50039990 116 Rfo de La Plata at Proyecto La Plata (d,c,b) ................................. 50043000 117 Rfo de La Plata at Comerio (d,s) ........................................ 50043800 120 VIII SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME-Continued Station number Page Rio de La Plata near Comerio (c,b) ....................................... 50044000 127 Rio Guadiana at Guadiana (d,s) ...................................... 50044830 129 Rio Guadiana near Naranjito (c,b) .................................... 50044850 136 Lago La Plata at Damsite near Toa Alta (e) ................................. 50045000 138 Rio de La Plata below La Plata Dam (d,s) .................................. 50045010 139 Rio de La Plata at Highway 2 near Toa Alta (d,c,b,s,p) ......................... 50046000 145 RIO HONDO BASIN Rio Hondo at Flood Channel near Catano (c,b) .............................. 50047530 150 RIO DE BAYAMON BASIN Lago de Cidra at Damsite near Cidra (e) ................................... 50047550 152 Rio de Bayamdn below Lago Cidra (d,s) ................................... 50047560 153 Rio de Bayamon near Aguas Buenas (c,b) .................................. 50047600 160 Rio de Bayamon near Bayamon (d) ...................................... 50047850 162 Rio Guaynabo near Bayamon (c,b) .................................... 50047990 163 Rio de Bayamon at Flood Channel at Bayamon (c,b,p) ......................... 50048510 165 RIO PUERTO NUEVO BASIN Rio Piedras: Rio Piedras at El Senorial (d,s) .......................................... 50048770 167 Rio Piedras near Rio Piedras (c,b,p) ...................................... 50048800 174 Rio Piedras at Hato Rey (d,c,b) ......................................... 50049100 176 Laguna San Jose: Laguna San Jose No 2 at San Juan (c,b) ................................... 50049820 179 Bahia de San Juan: Bahia de San Juan No 5 at San Juan (c,b) .................................. 50049920 180 QUEBRADA BLASINA BASIN Quebrada Blasina near Carolina (c,b) ..................................... 50050300 182 RIO GRANDE DE LOIZA BASIN Rio Grande de Loiza at Quebrada Arenas (d) ................................ 50050900 . 184 Quebrada Blanca at El Jagual (d,s) .................................... 50051150 185 Quebrada Salvatierra near San Lorenzo (d,s) ............................. 50051180 191 Rio Cayaguas at Cerro Gordo (d) ..................................... 50051310 198 Rio Grande de Loiza at Highway 183 near San Lorenzo (d,s) .................... 50051800 199 Rio Turabo above Borinquen (d,s) .................................... 50053025 206 Rio Grande de Loiza at Caguas (d,c,b,s) ................................... 50055000 213 Rio Caguitas near Aguas Buenas (d,s) ................................. 50055100 222 Rio Caguitas near Caguas (d,s) ...................................... 50055170 229 Rio Caguitas at Villa Blanca at Caguas (d,s) ............................. 50055225 235 Rio Caguitas at Highway 30 at Caguas (c,b) ............................. 50055250 242 Rio Bairoa at Bairoa (d,s) .......................................... 50055390 244 Rio Bairoa near Caguas (c,b) ........................................ 50055400 251 SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, /X FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME-Continued Station number Page Rio Gurabo: Rio Gurabo below El Mango (d,s) .................................... 50055750 253 Rio Valenciano near Juncos (d,s) .................................. 50056400 260 Rio Gurabo at Gurabo (d,s) ......................................... 50057000 267 Rio Gurabo near Gurabo (c,b) ....................................... 50057025 274 Rio Canas at Rio Canas (d,s) ........................................ 50058350 276 Lago Loiza at Damsite near Trujillo Alto (c,b,e) .............................. 50059000 284 Rio Grande de Loiza below Damsite (d,s) .................................. 50059050 286 Rio Grande de Loiza below Trujillo Alto (c,b) ............................... 50059100 292 Rio Grande de Loiza at Carolina (e) ...................................... 50061000 294 Rio Canovanas near Campo Rico (d) .................................. 50061800 295 RIO ESPIRITU SANTO BASIN Quebrada Sonadora near El Verde (d) ................................. 50063440 298 Quebrada Toronja at El Verde (d) .................................... 50063500 299 Rio Espiritu Santo near Rio Grande (d,c,b) ................................. 50063800 300 Rio Grande near El Verde (d) ....................................... 50064200 303 RIO MAMEYES BASIN Rio Mameyes near Sabana (d,s) ......................................... 50065500 304 RIO SABANA BASIN Rio Sabana at Sabana (d) .............................................. 50067000 319 RIO FAJARDO BASIN Rio Fajardo near Fajardo (d,c,b,p) ........................................ 50071000 320 Rio Fajardo below Fajardo (c,b) ......................................... 50072500 323 RIO BLANCO BASIN Quebrada Guaba near Naguabo (d) ....................................... 50074950 325 Rio Icacos near Naguabo (d) ........................................... 50075000 326 RIO HUMACAO BASIN Rio Humacao at Las Piedras (d) ......................................... 50081000 328 Rio Humacao at Highway 3 at Humacao (c,b) ............................... 50082000 329 RIO GUAYANES BASIN Rfo Guayanes at Yabucoa (c,b,p) ........................................ 50083500 331 Rio Guayanes above mouth at Playa de Guayanes (c,b) ......................... 50086500 333 RIO MAUNABO BASIN Rio Maunabo at Lizas (d) ............................................. 50090500 335 Rio Maunabo at Maunabo (c,b) ......................................... 50091000 336 RIO CHICO BASIN Rio Chico at Providencia (c,b) .......................................... 50091800 338 RIO GRANDE DE PATILLAS BASIN Rio Grande de Patillas near Patillas (d,c,b) ................................. 50092000 340 Lago Patillas at Damsite near Patillas (e) ................................... 50093050 343 RIO SALINAS BASIN Rio Lapas near Rabo del Buey (d) ....................................... 50100200 346 Rio Majada at La Plena (d) ............................................ 50100450 347 SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME-Continued Station number Page RIO COAMO BASIN Rio Coamo at Coamo (d) .............................................. 50106100 348 Rio Coamo near Coamo (c,b) ........................................... 50106500 349 RIO DESCALABRADO BASIN Rio Descalabrado near Los Llanos (d) ..................................... 50108000 351 RIO JACAGUAS BASIN Rio Toa Vaca above Lago Toa Vaca (d,s) ............................... 50110900 352 Lago Guayabal at Damsite near Juana Di'az (e) .............................. 50111300 359 Rio Jacaguas at Juana Di'az (d) .......................................... 50111500 360 RIO INABON BASIN Rio Inab6n at Real Abajo (d) ........................................... 50112500 362 RIO BUCANA BASIN Rio Bucand: Rio Cerrillos above Lago Cerrillos near Ponce (d) ............................ 50113800 363 Rio Cerrillos near Ponce (d,c,b) ......................................... 50114000 364 Rio Bucana at Hwy 14 Bridge near Ponce (d) ............................... 50114390 367 RIO PORTUGUES BASIN Rio Portugue"s near Ponce (d,c,b) ........................................ 50115000 368 Rio Portugues at Ponce (c,b,p) .......................................... 50116200 371 RIO GUAYANILLA BASIN Rio Guayanilla near Guayanilla (d) ....................................... 50124200 373 Rio Guayanilla at Central Rufina (c,b,p) ................................... 50124700 374 RIO YAUCO BASIN Lago Lucchetti at Damsite near Yauco (e) .................................. 50125780 376 RIO LOCO BASIN Lago Loco at Damsite near Yauco (e) ..................................... 50128900 377 Rio Loco at Guanica (c,b,p) ............................................ 50129700 378 RIO GUANAJIBO BASIN Rio Guanajibo at Highway 119 at San German (d) ............................ 50131990 382 Rfo Guanajibo near San German (c,b) ..................................... 50133600 383 Rio Rosario near Hormigueros (d,c,b,s) ................................ 50136400 385 Rio Guanajibo near Hormigueros (d,c,b,p) .................................. 50138000 394 RIO YAGUEZ BASIN Rio Yagiiez near Mayagiiez (c,b) ........................................ 50138800 398 RIO GRANDE DE ANASCO BASIN Lago Guayo at Damsite near Castaner (e) ............................... 50141500 400 Rio Grande de Anasco near Lares (c,b) .................................... 50143000 401 Rio Grande de Anasco near San Sebastian (d,c,b,s) ............................ 50144000 403 Rio Grande de Anasco near Anasco (c,b,p) ................................. 50146000 406 RIO CULEBRINAS BASIN Rio Culebrinas near San Sebastian (c,b) ................................... 50147600 410 Rfo Culebrinas at Highway 404 near Moca (d) ............................... 50147800 412 Rio Culebrinas near Aguada (c,b,p) ....................................... 50149100 413 SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, XI FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME-Continued Station number Page VIEQUES, P.R. Quebrada La Mina near Esperanza (e) ..................................... 50232000 415 Quebrada Pilon at Colonia Puerto Real (e) .................................. 50233000 416 Discharge at partial-record stations and miscellaneous sites Low-flow partial-record stations .......................................... 418 Analyses of samples collected of water-quality partial-record stations and miscellaneous sites ....................................... 430 ST THOMAS, US VIRGIN ISLANDS Bonne Resolution Gut at Bonne Resolution (d) .............................. 50252000 514 Turpentine Run at Mount Zion (d) ....................................... 50274000 515 ST JOHN, US VIRGIN ISLANDS Guinea Gut at Bethany (d) ............................................. 50295000 516 ST CROIX, US VIRGIN ISLANDS River Gut at Hwy 66 at Fairplanes (d) .................................... 50333700 517 Bethlehen Gut at Hwy 66 at Fairplanes (d) ................................. 50334500 518 Jolly Hill Gut at Jolly Hill (d) .......................................... 50345000 519 XII GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED Page RIO GUAJATACA BASIN Well 182422067015100 Local number 165 ................................................. 446 Well 182647066552400 Local number 202 ................................................. 447 RIO GRANDE DE ARECIBO BASIN Well 182737066370900 Local number 204 ................................................. 448 RIO GRANDE DE MANATI BASIN Well 182757066325600 Local number 206 ................................................. 449 Well 182710066303700 Local number 207 ................................................. 450 Well 182308066260400 Local number 210 ................................................. 451 RIO CIBUCO BASIN Well 182647066201700 Local number 70 .................................................. 452 Well 182615066235300 Local number 211 ................................................. 453 Well 182515066194000 Local number 212 ................................................. 455 Well 182330066185700 Local number 213 ................................................. 456 RIO DE LA PLATA BASIN Well 182746066170800 Local number 214 ................................................. 457 Well 182530066135400 Local number 216 ................................................. 458 Well 182655066142400 Local number 217 ................................................. 459 Well 182804066173500 Local number DA-1 ................................................ 460 Well 182620066163403 Local number HG-4 ................................................ 461 Well 182657066162700 Local number SA-1 ................................................ 462 Well 182657066162701 Local number SA-3 ................................................ 463 Well 182548066164401 Local number MA-2 ................................................ 464 Well 182526066165001 Local number SR-2 ................................................ 465 Well 182654066150600 Local number TB-1 ................................................ 466 RIO HONDO TO RIO PUERTO NUEVO BASINS Well 182441066082600 Local number 219 ................................................. 467 Well 182511066045401 Local number PN-2 ................................................ 468 Well 182435066052701 Local number PN-5 ................................................ 469 Well 182445066043401 Local number PN-6 ................................................ 470 Well 182443066041502 Local number PN-8c ............................................... 471 Well 182417066042700 Local number PN-10 ............................................... 472 Well 182349066032600 Local number PN-13 ............................................... 473 Well 182406066034700 Local number PN-19 ............................................... 474 RIO GRANDE DE LOIZA BASIN Well 181550065593201 Local number 50 .................................................. 475 Well 182515065594100 Local number 222 ................................................. 476 Well 181513065554601 Local number CJ-TW3B ............................................. 477 Well 181352066025300 Local number CJ-TW19A ............................................ 478 GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED-Continued XIII Page RIO HERRERA TO RIO ANTON RUIZ BASINS Well 181823065401900 Local number RF-04 ............................................... 479 Well 181917065382701 Local number RF-12 ............................................... 480 Well 182131065241100 Local number RP-04 ............................................... 481 Well 182138065431800 Local number RS-02 ............................................... 482 RIO HUMACAO TO RIO SECO BASINS Well 175858066100200 Local number 6 ................................................... 483 Well 180415065513900 Local number 96 .................................................. 484 Well 175719066085500 Local number P-13 ................................................. 485 RIO SALINAS TO RIO JACAGUAS BASINS Well 175829066232200 Local number 87 .................................................. 489 Well 180002066132200 Local number HW-TW-01 ........................................... 490 Well 180001066122002 Local number HW-TW-03C .......................................... 491 Well 175947066130601 Local number HW-TW-05B .......................................... 492 Well 175957066123400 Local number HW-TW-13 ........................................... 493 Well 175946066102000 Local number HW-TW-14 ........................................... 494 Well 175903066165000 Local number PG-07 ............................................... 495 Well 175943066224800 Local number PS-07 ................................................ 499 Well 180206066135500 Local number RM-05 ............................................... 503 Well 180104066152300 Local number RM-10 ............................................... 504 RIO INABON TO RIO LOCO BASINS Well 180133066503300 Local number 132 ................................................. 505 Well 175900066354200 Local number 141 ................................................. 506 Well 180045066381600 Local number AN-1 ................................................ 507 RIO GUANAJIBO BASIN Well 180132067033800 Local number 143 ................................................. 511 RIO CULEBRINAS BASIN Well 182442067091700 Local number 200 ................................................. 512 ST. CROIX, U.S. VIRGIN ISLANDS Well 174225064472000 Local number 2 ................................................... 522 Well 174243064475100 Local number 3 ................................................... 523 Well 174316064480800 Local number 13 .................................................. 524 ST. THOMAS, U.S. VIRGIN ISLANDS Well 182038064550300 Local number 6 ................................................... 525 Well 182038064580000 Local number 8 ................................................... 526 ST. JOHN, U.S. VIRGIN ISLANDS Well 181956064464500 Local number 11 .................................................. 527 XIV WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 DISCONTINUED STREAMFLOW STATIONS The following continuous-record strearaflow stations in Puerto Rico and the U.S. Virgin Islands have been discontinued or converted to partial-record stations. Daily strearaflow or stage records were collected for the period of record shown for each station. Station number 50007000 50010600 50011000 50011200 50011400 50013000 50014000 50016000 50021000 50021050 50021500 50023000 50027200 50029000 50031500 50035200 50035950 50038360 50038600 50038700 50038900 50039600 50043200 50043400 50044600 50044650 50044800 50045700 50047535 50047540 50047820 50048000 50049000 50049310 50053050 50054000 50055650 50056000 50056900 50058300 50059000 50061300 50062500 50063300 50065700 50072000 50073200 50073400 50074000 50075500 50076000 50077000 50077400 50078500 50081500 50082000 50082200 50082800 50083500 50084000 Station name Quebrada de los Cedros near Isabela Rio Guajataca above Lago de Guajataca Canal Diversion Lago Guajataca Rio Guajataca below Lago Guajataca Rio Guajataca above mouth near Quebradillas Rio Camuy near Lares Rio Criminales near Lares Rio Camuy near Camuy Rio Pellejas at Central Pellejas Rio Pellejas below Central Pellejas Rio Pellejas near Utuado Rio Vivi near Central Pellejas Rio Grande de Arecibo blw. Lago dos Bocas Rio Grande de Arecibo at Central Cambalache Rio Sana Muerto near Orocovis Rio Grande de Manati at Hwy 145 at Ciales Rio Cialitos at Hwy 649 at Ciales Rio Mavilla near Corozal Rio Unib6n near Morovis Rio Morovis at Morovis Rio Indio at Vega Baja Rio Cibuco at Central San Vicente Rio Usabon near Barranquitas Rio Aibonito Tributary near Aibonito Rio Guadiana near Naranjito Quebrada del Toro near Naranjito Quebrada Anones near Naranjito Rio Lajas at Toa Alta Rio de Bayamon at Arenas Rio Sabana at Vista Monte Rio de Bayamon at Hwy 174 near Bayamon Rio de Bayam6n at Bayamon Rio Piedras at Rio Piedras Quebrada Josefina at Piftero Avenue Rio Turabo at Borinquen Quebrada de las Quebradillas near Caguas Quebrada Caimito near Juncos Rio Valenciano near Las Piedras Quebrada Mamey near Gurabo Quebrada Arena near Caguas Rio Piedras at Rio Piedras Rio Canovanillas near Loiza Rio Herrera near Colonia Dolores Rio Espiritu Santo near El Verde Rio Mameyes at Hwy 191 at Mameyes Rio Fajardo at Fajardo Rio Daguao at Daguao Quebrada Palma at Daguao Rio Santiago at Naguabo Rio Blanco at Florida Rio Blanco near Florida Rio Blanco at Rio Blanco Rio Blanco at Colonia La Fe Rio Anton Ruiz at Central Pasto Viejo Rio Humacao near Humacao Rio Humacao at Hwy 3 at Humacao Rio Humacao near La Suiza Rio Guayanes near Colonia Laura Rio Guayanes near Yabucoa Rio Limones near Yabucoa Drainage area (mi 2 ) 6.91 7.62 4.68 5.46 7.89 9.55 5.66 169 200 3.68 132 17 9.51 5.29 1.26 9.15 1.13 1.73 0.54 2.32 8.65 0.45 0.80 31.90 71.90 ,5 ,84 7.89 6.25 0.82 6.85 2.30 12.5 14.40 2.75 2.23 11.80 21.60 2.26 4.84 4.99 11.00 12.30 17.60 18.80 4.33 9.23 17.30 19.90 4.69 17.20 7.89 Period of record 1970 1984-89 1970 1969-70,1984-87 1969-70,1984-89 1969-71 1969-70 1969-73 1968-70 1972-75 1969-71 1969-75 1970-71 1969-83 1965-70 1972 1970-82 1969-70 1969-70 1968 1963,66,71 1969-72 1968-69,71 1968-71 1971 1971 1971 1966-75 1992-93 1992-93 1966 1963-67 1971-82, 1988-91 1984-90 1987-93 1969-71,73 1984-87 1971 1984-92 1971 1971-82,1987-93 1968-73 1968-72 1968-73 1967-85 1960-63 1966-82 1972-77 1966-82 1966-82 1983-85 1973-77 1967-70 1968 1973 1983-85 1965-66,1969-71 1969-82 1969-71 1969-71 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 DISCONTINUED STREAMFLOW STATIONS--Continued XV Station number 50085100 50086100 50086500 50087200 50091000 50091200 50091400 50091700 50091800 50094200 50094300 50094400 50095200 50095500 50099000 50106500 50106900 50107200 50108200 50108500 50111200 50111700 50111750 50112100 50112600 50113100 50113500 50114400 50114700 50115900 50116500 50119000 50121000 50122000 50124000 50124500 50125900 50126150 50128000 50129000 50129500 50129900 50130320 50136000 50141000 50145000 50147000 50214500 50215000 50231000 50276000 50292600 50294000 50295500 50332000 50333500 50337500 50348000 50349000 Station name Drainage area (mi 2 ) Rio Guayanes at Central Roig 26.60 Rio del Ingenio at Comunas 5.50 Rio Guayanes at Playa Guayanes 34.00 Cano Santiago near Central Roig 6.04 Rio Maunabo at Maunabo 12.40 Rio Maunabo near Maunabo 12.70 Rio Jacaboa near Lamboglia 4.13 Rio Chico at Patillas 6.82 Rio Chico at Providencia 4.90 Rio Grande de Patillas at Patillas 27.90 Rio Grande de Patillas at Providencia 29.00 Rio Nigua at Pitahaya 5.86 Rio Guamani at Guayama 8.22 Rio Guamani near Guayama 12.30 Quebrada Aguas Verdes near Salinas 0.39 Rio Coamo near Coamo 46.00 Rio Coamo below Lago Coamo near Coamo 65.40 Rio Coamo at mouth near Santa Isabel 69.30 Rio Descalabrado at Las Ollas 13.90 Rio Descalabrado near Santa Isabel 18.10 Rio Toa Vaca near Villalba 21.40 Rio Jacaguas near Juana Diaz 53.20 Rio Jacaguas below Quebrada Guandbana 56.30 Rio Jacaguas near Arus 59.60 Rio Inab6n at Goto Laurel Rio Guayo near Goto Laurel 11.80 Rio Inabon near Arus 30.20 Rio Bucana near Ponce 25.60 Rio Bucana near Playa de Ponce 28.40 Rio Portugues at Hwy 14 at Ponce Rio Portugues at Highway 2 Bypass at Ponce 20.50 Rio Matilde at Ponce 19.40 Rio Tallaboa at Pefiuelas 24.20 Rio Tallaboa at Tallaboa 31.50 Rio Guayanilla nr Guayanilla 18.50 Rio Guayanilla at Guayanilla 20.80 Rio Duey above Diversion near Yauco 8.93 Rio Yauco above Diversion Monserrate near Yauco 27.20 Rio Yauco near Yauco 45.50 Rio Loco near Yauco 8.50 Rio Loco near Guanica 21.00 Laguna Cartagena near Boquer6n Quebrada Mamey at Joyuda 0.38 Rio Rosario at Rosario 16.40 Rio Yahuecas near Adjuntas 15.40 Rio Grande de Anasco at El Espino 108.00 Rio Culebrinas at San Sebastian 16.70 Quebrada Resaca near Monte Resaca, Culebra 0.23 Drainage Canal at Culebra Airport, Culebra 0.08 Quebrada Confresi Tributary near Isabel II, Vieques 0.28 Turpentine Run at Mariendal 2.97 Lameshur Bay Gut at Lameshur, St. John 0.38 Fish Bay Gut at Fish Bay, St. John 1.48 Cruz Bay Gut at Cruz Bay, St. John, VI 0.09 River Gut at River 1.42 River Gut near Golden Grove 5.40 Gut 4.5 at Cane Valley 0.21 Salt River at Canaan 0.36 Gut 10 near Altona 0.13 Period of record 1965-66,1968,70 1965-66,1968-69 1965-66,1968-71 1965-71 1965,67,1969-82 1971-72 1965-73 1965,1969-72 1965,1967-69,1971 1967,1969,1971 1971 1965,1969,1970-71,1973 1969-71 1969-70 1989 1967-68,1984-85,1986 1967-68 1967-68 1965,1967-71 1966-67 1966-70 1966-68 1989 1966-67 1967-71 1965, 1968-71 1964-65 1965-81 1964-67 1965-82 1964-65 1965-66 1959-82 1959-63 1961-69 1971-82 1977-80 1978-85 1962-64,1977-85 1963-67 1963-69 1984-86 1986-88 1975-86 1980-85 1959-66,1961-63 1960-82 1991-93 1991-93 1991-93 1963-69,1978-86 1992-94 1992-94 1992-93 1991-93 1990-93 1991-93 1991-93 1991-93 XVI THIS PAGE WAS LEFT BLANK INTENTIONALLY WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 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 Geological Survey, the data are published annually in this report series entitled "Water Resources Data for Puerto Rico and the U.S. Virgin Islands, 1995." This report includes records on both surface and ground water. Specifically, it contains: (1) Discharge records for 74 streamflow-gaging stations, stage only for 5 gaging stations, daily sediment records for 23 streamflow stations, 94 partial-record or miscellaneous streamflow stations, stage records for 14 reservoirs, and (2) water-quality records for 16 streamflow-gaging stations, and for 42 ungaged streamsites, 11 lake sites, 2 lagoons, and 1 bay; and (3) water-level records for 65 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 1975-76, 1977, 1978, 1979-80, 1981-82, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, and 1994 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 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-95-1." 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. Beginning with the 1990 water year to 1994, water-data reports are also available on Compact Disc-Read Only Memory (CD-ROM). 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. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 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 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 Department of Housing Puerto Rico Highway Authority Puerto Rico Department of Natural and Environmental Resources Puerto Rico Department of Health Puerto Rico Electric and Power Authority Puerto Rico Solid Waste Management Authority Puerto Rico Legislature Puerto Rico Civil Defense U.S. Department of the Interior, Office of Territorial and International Affairs U.S. Virgin Islands Department of Planning and Natural Resources Funds were also provided by the Corps of Engineers, U.S. Army, for the collection of records at six gaging stations published in this report. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 SUMMARY OF HYDROLOGIC CONDITIONS Rainfall Rainfall throughout Puerto Rico during the 1995 water year (October 1994 to September 1995) averaged about 98 percent of normal. During the months of February, May, July, and September rainfall was above normal (table 1). Significant above-normal conditions were observed particularly during February, when the amount of rainfall was almost double the normal value. During the other months, rainfall was below-normal, especially during December and April when rainfall averaged 69 percent and 45 percent of normal, respectively. Rainfall averaged about 95 percent of normal in northern Puerto Rico, 101 percent of normal in southern Puerto Rico, 93 percent of normal in eastern Puerto Rico, and 102 percents of normal in western Puerto Rico. Monthly average rainfall islandwide for the 1995 water year and for the 30 year reference period 1961-1990 used to define normal rainfall, as reported by the National Oceanic and Atmospheric Administration, are listed in table 1. Table 1. Islandwide monthly rainfall and annual averages for the 1995 water year and the 30-year reference period, 1961-1990 1995 Water Year 30-year normal Month (inches) (inches) OCT 6.96 8.29 NOV 5.37 6.55 DEC 3.03 4.38 JAN 2.61 2.86 FEE 4.79 2.52 MAR 2.53 3.01 APR 2.00 4.46 MAY 7.63 6.96 JUN 4.57 4.99 JUL 6.29 5.08 AUG 6.11 6.89 SEP 9.78 7.14 TOTAL 61.67 63.13 Surface Water Streamflow during 1995 water year was generally normal in western and eastern Puerto Rico, but below normal to deficient in the northern and southern regions (fig. 1). The water year began with streamflow deficient in most parts of the Island, especially in the northern region. A comparison of the monthly-mean flows during the 1995 water year, the long-term median of the monthly-mean flows, and the maximum and minimum monthly-mean flows for the period of record at the index stations on the Rio Grande de Anasco, the Rio Grande de Manati, the Rio Inabon, and the Rio Fajardo are shown in figure 1. Historical minimum monthly-mean flows were recorded at the Rio Grande de Manati and Rio Inabon index stations. At the Rio Grande de Manati index station, in the northern area, historical minimum monthly-mean flows were recorded from October through January and during April. In the southern area, the Rio Inabon at Real Abajo index station recorded historical minimum monthly-mean flow during December. During the rest of the year, the streamflow conditions in Puerto Rico were generally near normal, except during May and September when moderate rainfall events WEST RIO GRANGE DE ANASCO NEAR SAN SEBASTIAN (50144000) NORTH RIO GRANGE DE MANATl AT HWY 2 NEAR MANATl (50038100) 10,000 1,000 - O N D 1994 FMAMJJAS 1995 SOUTH Rl'O INABON AT REAL ABAJO (50112500) 10,000 pi 1,000 100 UJ 10 1994 1995 EAST RIO FAJARDO NEAR FAJARDO (50071000) 1,000 ONDJFMAMJJAS 1,000 100 1o N D 1994 J F A M 1995 J J A S Unshaded area indicates range between highest and lowest monthly-mean discharges for the period of record to water year 1995. Figure 1.-Monthly-mean discharge of selected streams in Puerto Rico. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 occurred. Rainfall during May was caused mainly by cold fronts and troughs, which moved over Puerto Rico from the northwest. Streamflows in the western, northern, and eastern areas increased in May as a consequence of these rainfall events. Rainfall associated with Hurricanes Luis and Marilyn, which passed near the Island, produced an increase in streamflows during September in the northern, southern, and eastern areas. In the U.S. Virgin Islands, streamflow conditions followed the same general pattern as Puerto Rico throughout most of the 1995 year water. Significant floods were experienced in the U.S. Virgin Islands as a consequence of intense rainfall associated with Hurricane Marilyn, which passed over the islands during September 15-16, 1995. As much as 11.40 inches of rain fell on St. Croix on September 15. Maximum discharges were exceeded at two gaging stations (table 2). On St. Thomas, the gaging station at Turpentine Run at Mount Zion recorded a maximum discharge of 10,500 cubic feet per second, which exceeded the maximum previously recorded discharge of 5,420 cubic feet per second. The Jolly Hill Gut at Jolly Hill, St. Croix, had a peak discharge of 937 cubic feet per second, exceeding the maximum previously recorded discharge of 491 cubic feet per second. Table 2. Summary of discharges at streamflow-gaging stations where the previous maximum discharge was exceeded in the U.S. Virgin Islands during September 15, 1995 [mi2 , square miles; ft3/s, cubic feet per second] Station number 50274000 50345000 Station name Turpentine Run at Mount Zion, St . Thomas Jolly Hill Gut at Jolly Hill, St. Croix Drainage Period area of (mi 2 ) record 2.33 1963-69 1992-95 2.10 1963-68 1982-95 Previous maximum Maximum during Date Discharge September 15, 1995 (ftVs) discharge (ftVs) 5/23/69 5,420 10,500 11/7/84 491 937 Ground-Water Levels Ground-water levels in the most aquifers in Puerto Rico and the U.S. Virgin Islands generally declined during water year 1995. The ground-water levels declined as a result of below normal rainfall and sustained ground-water withdrawals caused by a rainfall deficit period that affected the islands during water year 1994. Record-low water levels were recorded at 26 of a total of 65 observation wells in Puerto Rico and the U.S. Virgin Islands during the water year 1995 (table 3). In the north coast limestone aquifers of Puerto Rico, the ground-water levels generally declined from October 1994 to May 1995. At the Sabana Hoyos index station, the ground-water level declined to 31.12 feet below land surface datum (May 12, 1995) or 0.02 feet below the previous lowest measurement on record (July 31, 1975). Ground-water levels rose 1.80 feet between June and September (fig. 2). In the south coast alluvial aquifers of Puerto Rico, the ground-water levels fluctuated in response to rainfall and streamflow patterns, irrigation, and ground-water withdrawal. At the Alomar index well, the water level declined 2.10 feet from October 1994 to May 1995 (fig. 2). However, the ground-water level decreased to 45.85 feet below land surface datum (April 7, 1995) which was 3.33 feet above the lowest level on record (49.18 feet below land surface datum, July 27, 1974). In the U.S. Virgin Islands (St. Thomas, St. Croix, and St. John) ground-water levels declined from October 1994 to September 1995 in response to diminished rainfall and sustained ground-water withdrawals. However, above normal rainfall produced by Hurricane Marilyn (September 15, 1995) caused a ground-water level rise of 23.60 feet at the Guinea Gut observation well in St. John between September 15-30, 1995 (fig. 2). WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 Table 3. Lowest ground-water levels recorded during 1995 water year and previous low ground- water levels at selected wells in Puerto Rico and the U.S. Virgin Islands. [PR, Puerto Rico; St.C, St. Croix; St.T, St. Thomas; St.J, St. John; mm-dd-yy, month-day-year; ft-blsd, feet below land-surface datum; mm-yy, month-year] Well name or Local number number Location Carmelo Barreto 202 PR Gilberto Rivera 204 PR Plazuela No. 2 206 PR Gelo Martinez 210 PR Sabana Hoyos #2 70 PR Rosario No. 2 211 PR Ponder osa TW-1 212 PR Pampano No . 2 213 PR Dorado Beach No. 7 214 PR Toa Baja TW-1 PR Monserrate TW-2 217 PR Ft. Buchanan No. 1 219 PR Alsacia No. 2 PN-6 PR Luis Mufioz Marin 1C PN-8c PR Las Americas No. 1 PN-10 PR Jardin Botanico No. 1 PN-13 PR Jardin Botanico No. 3 PN-19 PR CJ-TW 19A CJ-TW 19A PR HW-TW-01 HW-TW-0 1 PR HW-TW-03C HW-TW-03C PR HW-TW-05B HW-TW-05B PR RM # 10 RM # 10 PR GOLDEN GROVE 6 3 St.C WAPA-17 13 St.C VIEO-6 8 St.T 1995 lowest water level (ft-blsd) 453.96 53.10 6.03 85.50 31.12 194.10 75.33 65.68 21.10 10.68 3.72 55.67 13.65 16.18 6.92 17.87 13.43 25.70 34.44 59.10 27.13 35.77 41.05 27.88 32.67 Date (mm-dd-yy) 05-14-95 05-15-95 05-16-95 01-29-95 09-15-95 10-14-94 10-15-94 05-12-95 05-13-95 03-31-95 04-01-95 to 04-07-95 02-27-95 03-04-95 03-05-95 03-06-95 08-20-95 03-30-95 05-03-95 05-04-95 05-13-95 05-13-95 10-06-94 10-07-94 10-05-94 10-06-94 10-07-94 10-06-94 to 10-09-94 10-07-94 11-08-94 11-09-94 05-31-95 09-07-95 to 09-16-95 09-28-95 09-07-95 09-17-94 to 10-05-94 09-15-95 09-06-95 07-27-95 Previous lowest water level Date (Et-blsd) (mm-dd-yy) 452 52 5 85 31 193 75 61 21 10 3 52 13 16 6. 17 12. 25 31, 57 23 35 36 21 32 .80 .59 .89 .32 .10 .92 .03 .17 .01 .50 .21 .66 .26 .10 .74 .82 .63 .54 .98 .68 .95 .56 .76 .36 .11 06-26-86 04-15-94 04-11-90 04-12-90 09-29-94 07-31-75 07-22-94 to 07-26-94 09-30-94 08-08-94 07-23-94 07-24-94 08-17-94 06-09-94 09-27-94 09-30-94 09-30-94 09-30-94 09-18-94 09-19-94 09-19-94 09-20-94 09-04-94 to 09-08-94 09-17-94 09-20-94 to 09-23-94 09-17-94 09-18-94 09-19-94 09-19-94 09-20-94 08-28-90 08-29-90 09-30-94 05-23-92 09-08-94 09-09-94 Period of record (mm-yy) 11-85 10-86 10-85 10-85 02-60 10-85 10-85 10-85 11-85 11-92 11-85 12-85 7-89 2-89 10-89 3-89 6-91 9-91 4-88 12-88 4-88 3-89 3-82 2-90 10-91 to to to to to to to to to to to to to to to to to to to to to to to to to 9-95 9-95 9-95 9-95 9-95 9-95 9-95 9-95 4-95 9-95 9-95 9-95 9-95 9-95 9-95 9-95 9-95 9-95 9-95 9-95 9-95 9-95 9-95 9-95 9-95 GUINEA GUT 09-06-95 3-82 to 9-95 2 LJ a: ID </) O 1 LJ GO _r 25 30 35 39 40 41 42 43 44 45 46 WELL 70, SABANA HOYOS, PUERTO RICO OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1994 1995 I T WELL 87, ALOMAR 1, PUERTO RICO I______1______I OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1994 1995 a: I 10 25 40 1 I l 1 1 1 III WELL 11, GUINEA GUT ST. JOHN, U.S. VIRGIN ISLANDS j_____I_____1_____1_____I OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1994 1995 Figure 2.—Ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands. 8 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 Water Quality In water year 1995, the U.S. Geological Survey, in cooperation with local government agencies, collected water- quality data at 83 surface-water stations in Puerto Rico. The water-quality data collected at these stations included the major chemical constituents and several additional constituents that are listed in table 4. The highest concentration of each of these constituents detected during water year 1995 and the stations 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 1995 [All constituent concentrations are in milligrams per liter; *, Cyanide concentrations at all water-quality stations were below the detection limit (<0.010); MBAS, Methylene blue active substance] Station number Station name Constituent Concentration 50124700 50047530 50050300 50083500 50083500 * 50039500 50055250 Rio Guayanilla at Central Rufina Rio Hondo at Flood Channel near Catano Quebrada Blasina near Carolina Rio Guayanes near Yabucoa Rio Guayanes near Yabucoa -- Rio Cibuco at Vega Baja Rio Cagflitas at Caguas Sulfide Boron Manganese Iron Zinc Cyanide Phenols MBAS 4.8 2.6 3.7 14 0.06 <0.010 0.014 3.9 The presence of high concentrations of fecal coliform (FC) and fecal streptococci (FS) bacteria continued to be the principal surface-water quality problem in Puerto Rico during water year 1995. The highest concentrations observed during this year were in stations 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 main sources of contamination in surface-water systems in Puerto Rico are discharges of liquid waste from industrial and municipal sources. The highest concentrations 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 23 stations in Puerto Rico during the 1995 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 construction of urbanizations and roads, agriculture and activities where soil movement was involved. The high suspended sediment concentrations affects the water quality for drinking water and decrease the storage capacities of reservoirs used for water supply. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 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) Prgram 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, dirverse, 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 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 1995 water year that began October 1, 1994 and ended September 30, 1995. 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 11. 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. 7 0 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 Station Identification Numbers Each data station, whether streamsite 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. 12). ATLANTIC 66 00' EXPLANATION FECAL COLIFORM • < 1000 • 1000-10,000 • 10,000-100,000 • 100,000-1,000,000 Figure 3.--Location of fecal coliform bacteria concentration at sampled sites. 45 10 -L. 1 -~—-y\ ^ ,. _._ „„ . . , ^,.. . CAHIBoEAN &A EXPLANATION ] FECAL STREPTOCOCCI 4 < 1000 ^ 1000-10,000 ^ 10,000-100,000 ^ 100,000-1,000,000 Figure 4.--Location of fecal streptococci bacteria concentration at sampled sites. •"\!\x 11478 N •^14 ^~--.. / / i -"X (P1- "\ """"j 0105 A- 1440^rx V.,..^; X -X A' " \~-. \ ( i «;.- C,wa<!\ <-„ C---"" "^ rx X ! S ^ :.;.? A-Msixi V> J>.i"«>~V V \ s> \ \ \^>v. / ^x^AX \, ( S N "m,, A As r^sii*/ K ,-.. ' I <-' W| ™*< / - -••"•--;..„. Li4i^l sx Jl ^kcwgi^" Y / ,,'X#>i ^- ei .,* /\'~ A X0610 i- W A ftl' ...«^ 4 * K. x' \ "~" ,^k"' r ,' ). A / "" \y fx\;> Vs /! R;i; G^ii^/te/' 1364A,, \ VA1380 —^ V^13v,.,j ru""^x>v; v \ x V JL J '* ? < /^ > ~VA ( ; / XA' 13199° ^C.^;t/' "Vvi"li .--'' f'""X., 7.\ 0920 CONT1NOUS STREAMFLOW STATION AND NUMBER 0930 LAKE-ELEVATION STATION | AND NUMBER , 0564 DAYLY SEDIMENT STATION | ^ AND NIMBER | Figure 5.--Location of surface-water stations in Puerto Rico, 65'DCT ATLANTIC OCEAN ( X <„..., 1247 05&3S5 \ SEA 05525,0 *P \ ' *T0550 : EXPLANATION QUALITY OF WATER STATIONS ^0430 BIOLOGICAL If OS20 SEDIMENT (Bi-monthly) Figure 6.--Location of water-quality stations in Puerto Rico. 67" 15' 67'00' 45 ! 18'30 ! 15' 30' 15' v^ 66"00' 45' 65"30 :i SE/i, EXPLANATION A LOW-FLOW PARTIAL-RECORD STATION 043850 STATION IDENTIFICATION NUMBER Figure 7.--Location of low-flow partial-record stations in northcentral Puerto Rico. ATLANTIC OCEAN / SEA V EXPLANATION WELL AND WELL NUMBER Figure 8.--Location of ground-water stations in Puerto Rico. 65 05' ST. THOMAS j*a**~+*^ Vk *N^\ —TX/ ^520V\/ Charlorie Afnalie !8 r 18" 3 4 KILOMETERS 2 3,4 MJL.ES 64 !5U S 45" j4CT i 17*45' ST CROiX /< i „01234 KSLOMETER3 i ; j • - 01234 MILES EXPLANATION A3490 SURFACE-WATER STATION AND NUMBER 17 Figure 9.--Location of surface-water stations in the U.S. Virgin Islands. 65"05' 65"00 64'50" 18 8 Charlott alie —9. 01234 KILOMETERS « 01234 KILOMETERS 2 3 , 4 MILES 17-45' 49 ! 64'35 ! """"T—— I ST. CROIX 0 1 2 3 4 KILOMETERS G 1 2 3 4 MILES WELL AND WELL NUMBER Figure 10.--Location of ground-water stations in the U.S. Virgin Islands. 18°i0 C ' 8°05'0: Isla de P.R. iSABi jX-^-»-r- " \ » J ' SEGUMDA C I \ t ^ i ^•\ r^~, \ -H->_^4 1 ^-rrn\f"V\^- ^ ^ - Ov"\\> <i i V X-H.. ~\ r\ < v ; r c ^ ^ EXPLANATION 2320 SURFACE-WATER STATION AND NUMBER Figure 11.--Location of surface-water stations in Vieques Island. <o 20 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 66°53' 52' 51* 50' 49' 48' 66°47' 18° 02' — or — I8°00' I7°59' 134 132 J 131* \ XI16 >< •27 •74 C4/ c — c COORDINATES FOR WELLS 27 (180160066474000) AND 74 (180136066471000) COORDINATES FOR WELLS 132 (180133066603300) ~ AND 194 (180120066603200) COORDINATES FOR WELL 131 (180068066602700) COORDINATES FOR WELL 16 (176022066406800) Figure 12.--Grid showing system for numbering veils 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. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 2 1 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. 22 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 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. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 23 Statistics of monthly mean data A tabular summary of the mean (line headed "MEAN"), maximum (line headed "MAX"), a^d 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). 24 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 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 a 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 ftVs; to whole numbers between 10 and 1,000 ftVs; 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. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 25 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. Al, 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. 26 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 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. Cl. Methods used by the Geological Survey laboratories are given in TWRI, Book 1, Chap. D2; Book 3, Chap. C2; Book 5, Chap. Al, A3, and A4. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 2 7 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. 28 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 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 local needs. 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 (Isd). 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. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 29 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 geologic 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 measurment 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. 30 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 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 WATSTORE DATA The U.S. Geological Survey is the principal Federal water-data agency and, as such, collects and disseminates about 70 percent of the water data currently being used by numerous State, local, private, and other Federal agencies to develop and manage our water resources. As part of the U.S. Geological Survey's program of releasing water data to the public, a large-scale computerized system has been developed for the storage and retrieval of water data collected through its activities. The National Water-Data Storage and Retrieval System (WATSTORE) was established in 1972 to provide an effective and efficient means for the processing and maintenance of water data collected through the activities of the U.S. Geological Survey and to facilitate release of the data to the public. A variety of useful products, ranging from data tables to complex statistical analyses such as Log Pearson Type III, can be produced using WATSTORE. The system resides on the central computer facilities of the U.S. Geological Survey at its National Center in Reston, Virginia, and consists of related files and data bases. * Station Header File - Contains descriptive information on over 440,000 sites throughout the United States and its territories where the U.S. Geological Survey collects or has collected data. * Daily Values Files - Contains over 220 million daily values of streamflow, stages, reservoir contents, water temperatures, specific conductances, sediment concentrations, sediment discharges, and ground-water level. * Peak Flow File - Contains approximately 500,000 maximum (peak) streamflow and gage-height values at surface-water sites. * Water-Quality Data - Contains approximately 2 million analyses of water samples that describe the chemical, physical, biological, and radio-chemicals characteristics of both surface and ground water. * Ground-Water Site Inventory Data Base - Contains inventory data for over 900,000 wells, springs, and other sources of ground water. The data includes site location, geohydrologic characteristics, well-construction history, and one-time field measurements such as water temperature. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 3 f In 1976, the U.S. Geological Survey opened WATSTORE to the public for direct access. The signing of a Memorandum of Agreement with the Survey is required to obtain direct access to WATSTORE. The system can be accessed either synchronously or asynchronously. The requestor will be expected to pay all computer costs he/she incurs. Direct access may be obtained by contacting: U.S. Geological Survey National Water Data Exchange 421 USGS National Center Reston, Virginia 22092 In addition to providing direct access to WATSTORE, data can be provided in various machine-readable formats on magnetic tape or 5-1/4 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's offices. (See address on the back of the title page). DEFINITION OF TERMS Terms related to streamflow, water-quality, and other hydrologic data as used in this report, are defined below. See also the table for converting inch- pound units to the International System of units (SI) on the inside of the back cover. 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 about 326,000 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 measure of ATP therefore provides a sensitive and rapid estimate of biomass. ATP is reported in micrograms per liter of the original water sample. Algae 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 a stationary phase and is expressed as milligrams dry weight of algae produced per liter of sample. Aquifer is a geologic formation, group of formations, or part of a formation that contains sufficient saturated permeable material to yield significant quantities of water to wells and springs. Artesian means confined and is used to describe a well in which the water level stands above the top of the aquifer, tapped by the well. A flowing artesian well is one in which the water level is above the land surface. 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. They are characterized as aerobic or facultative anaerobic, gram-negative, nonspore-forming, rod- shaped bacteria which ferment lactose with gas formation within 48 hours at 35°C. In the laboratory these bacteria are defined as all the organisms which produce colonies with a golden-green metallic sheen within 24 hours when incubated at 35°C +_ 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. 32 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 Fecal coliform bacteria are bacteria that are present in the intestines 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 which produce blue colonies within 24 hours when incubated at 44.5°C _+ 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 also in intestines of warm-blooded animals. Their presence in water is considered to verify fecal pollution. They are characterized as Gram-positive, cocci bacteria which are capable of growth in brain-heart infusion broth. In the laboratory they are defined as all the organisms which produce red or pink colonies within 48 hours at 35°C + 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. Bed material is the unconsolidated material of which a streambed, lake, pond, reservoir, or estuary bottom is composed. 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 the 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. The ash mass values of zooplankton and phytoplankton are 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 values are 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 the ash mass and represents the actual matter. The organic mass is expressed in the same units as for ash and dry mass. Wet mass is the mass of living matter plus contained water. Bottom material: See Bed material. Cells/volume refers to the number of cells of any organism which is counted by using a microscope and grid or counting cell. Many planktonic organisms are multicelled and are counted according to the number of contained cells per sample, usually milliliters (mL) or liters (L). 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 natural water color or with carbonaceous organic pollution from sewage or industrial wastes. Chlorophyll refers to the green pigments of plants. Chlorophyll a and b are the two most common green pigments in plants. Color unit is produced by one milligram per liter of platinum in the form of the chloroplatinate ion. Color is expressed in units of the platinum-cobalt scale. 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. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 33 Control designates a feature downstream from the gage that determines the stage-discharge relation at the gage. This feature may be a natural constriction of the channel, 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 o'f the stream or to prevent the intrusion of salt water. Cubic foot per second (ft3/s) is the rate of discharge representing a volume of 1 cubic foot passing a given point during 1 second and is equivalent to 7.48 gallons per second or 448.8 gallons per minute or 0.02832 cubic meters per second. Cubic foot per second-day (ftVs/day) 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, approximately 1.9835 acre-feet, about 646,000 gallons, or 2,445 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 that the runoff is distributed uniformly in time and area. Discharge is the volume of water (or more broadly, volume of fluid plus suspended sediment), that passes a given point within a given period of time. 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. Annual 7-day minimum is 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 statistic.) Dissolved refers to that material in a representative water sample which passes through a 0.45 um 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. 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 the analytical determination of dissolved solids, the bicarbonate (generally a major dissolved component of water) is converted to carbonate. Therefore, in the mathematical calculations of dissolved-solids concentration, the bicarbonate value, in milligrams per liter, is multiplied by 0.492 to reflect the change. Diversity index is a numerical expression of evenness of distribution of aquatic organisms. The formula for diversity index is: __ s d = - Z ^_ Iog2 "±_ n n Where "i 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 stream at a specified location is that area, measured in a horizontal plane, enclosed by a topographic divide from which direct surface runoff from precipitation normally drains by gravity into the stream above the specified point. Figures of drainage area given herein include all closed basins, or noncontribution areas, within the area unless otherwise noted. 3 4 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 Drainage basin is a part of the surface of the earth that is occupied by a drainage system, which consists of a surface stream or a body of impounded surface water together with all tributary surface streams and bodies of impounded surface water. Gage height (G.H.) is the water-surface elevation referred to some arbitrary 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 particular site on a stream, canal, lake, or reservoir where systematic observations of hydrologic data are obtained. Ground-water station is a well at which observations of ground-water level are made, either continuously by recorder, or periodically by hand. In addition, various chemical or physical parameters may be obtained, usually on a periodic basis. 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 equivalent calcium carbonate (CaCO3). Hydrologic Bench-Mark Network is a network 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. Hydrologic unit is a geographic area representing part or all of a surface drainage basin or distinct hydrologic feature as delineated by the Office of Water Data Coordination on the State Hydrologic Unit Maps; each hydrologic unit is identified by an eight-digit number. Land-surface datum (Isd) is. a datum plane that is approximately at land surface at each ground-water observation well. Measuring point (MP) is an arbitrary permanent reference point from which the distance to the water surface in a well is measured to obtain the water level. 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) is a unit expressing the concentration of a chemical element as the mass (micrograms) of the element per unit mass (gram) of material analyzed. Micrograms per liter (UG/L, ug/L) is a unit expressing the concentration of chemical constituents in solution as mass (micrograms) of solute per unit volume (liter) of water. One thousand micrograms per liter is equivalent to one milligram per liter. Milligrams per liter (MG/L, mg/L) is a unit for expressing the concentration of chemical constituents in solution. Milligrams per liter represent the mass of solute per unit volume (liter) of water. Concentration of suspended sediment also is expressed in mg/L, and is based on the mass of sediment per liter of water-sediment mixture. Conversion of chemical concentrations in Mg/L to milliequivalents per liter can be done by using the factors in table 4. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 Table 5. Factors for conversion of chemical constituents in milligrams per liter to milliequivalents per liter. Ion Aluminum ( Al+3 )*........ Ammonia as NH4+1 ........ Barium (Ba+2 )........... Bicarbonate (HCO3-1) . . . . Bromide (Br-1) .......... Calcium (Ca+2) .......... Carbonate (C03-2) ....... Chloride (Cl-1) ......... Chromium (Cr+6 )*........ Cobalt (Co+2) *.......... Copper (Cu+2 )*.......... Cyanide (CN-1) .......... Fluoride (F-l) .......... Hydrogen (H+l) .......... Hydroxide (OH-1) ........ Multiply by 0.11119 .05544 .01456 .01639 .01251 .04990 .03333 .02821 .11539 .03394 .03148 .03844 .05264 .99209 .05880 Ion Iodide (1-1) ......... Iron (Fe+3) .......... Lead (Pb+2) .......... Lithium (Li+1) ....... Magnesium (Mg+2) ..... Manganese (Mn+2 )*.... Nickel (Ni+2) ........ Nitrate (N03-1) ...... Nitrite (N02-1) ...... Phosphate (P04-3) .... Potassium (K+l) ...... Sodium (NA+1) ........ Strontium (Sr+2) ..... Sulfate (S04-2) ...... Zinc (Zn+2) *......... Multiply by 0.00788 .05372 .00965 .14411 .08226 .03640 .03406 .01613 .02174 .03159 .02557 .04350 .02283 .02082 .03060 *Constituent reported in micrograms per liter; multiply by factor and divide results by 1,000 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 in 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 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. National Trends Network (NTN) is a 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). 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 unit area habitat, usually square meters (m2), acres, 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 milliliters (mL) or liters (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. Parameter Code is a 5-digit number used in the U.S. Geological Survey computerized data system, WATSTORE, to uniquely identify a specific constituent. The codes used in WATSTORE are the same as those used in the U.S. Environmental Protection Agency data system, STORET. The Environmental Protection Agency assigns and approves all requests for new codes. Partial-record station is a particular site where limited streamflow and/or water-quality data are collected systematically over a period of years for use in hydrologic analyses. 3 6 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 Particle-size is the diameter, in millimeters (mm), of a particle determined by either sieve or sedimentation methods. Sedimentation methods (pipet, bottom-withdrawal tube, visual-accumulation tube) 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). Particle-size classification used in this report agrees with recommendations made by the American Geophysical Union Subcommittee on Sediment Terminology. The classification is as follows: Classification Size (mm) Method of analysis Clay...... 0.00024 - 0.004 Sedimentation Silt...... .004 - .062 Sedimentation Sand...... .062 - 2.0 Sedimentation or sieve Gravel.... 2.0 -64.0 Sieve 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. Percent composition 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, mass or volume. 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. Pesticides are chemical compounds used to control undesirable organisms. Major categories of pesticides include insecticides, miticides, fungicides, herbicides, and rodenticides. Picocurie (PC, pCi) is one trillionth (1 X 10- 12) of the amount of ratioactivity 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. 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 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 siljceous shell. Their concentrations are expressed as number of cells per milliliter (cells/mL) of sample. 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. 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. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 3 7 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 by the plants (carbon method). Milligrams of carbon per area or volume per unit time [mg C/(m2.time)1 for periphyton and macrophytes and [mg C/(m3.time)T for phytoplankton are units for expressing primary productivity. They define 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 hour or day, depending on the incubation period. Milligrams of oxygen per area or volume per unit time TmgO / (m2.time)1 for periphyton and macrophytes and TmgO /(m3.time)] for phytoplankton are the units for expressing primary productivity. They define 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. Polychlorinated biphenyls (PCBs) are industrial chemicals that are mixtures of chlorinated biphenyl compounds having various percentages of chlorine. They are similar in structure to organochlorine insecticides. Radiochemical program is a network of regularly sampled water-quality stations where samples are collected to be analyzed for radioisotypes. The streams that are sampled represent major drainage basins in the conterminous United States. 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. Return period is the average time interval between occurrences of a hydrological event of a given or greater magnitude, usually expressed in years. May also be called recurrence interval. Runoff in inches (IN, in) shows the depth to which the drainage area would be covered if all the runoff for a given time period were uniformly distributed on it. Sediment is solid material that originates mostly from disintegrated rocks and is transported by, suspended in, or deposited from water; it 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 the bed and very close to it. In this report, bed load is considered to consist of particles in transit within 0.25 ft of the streambed. Bed load discharge (tons per day) is the quantity of bed load measured by dry weight that moves past a section as bed load in a given time. Suspended sediment is the sediment that at any given time is maintained in suspension by the upward components of turbulent currents or that exists in suspension as a colloid. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 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). Mean concentration is the time-weighted concentration of suspended sediment passing a stream section during a 24-hour day. Suspended-sediment discharge (tons/day) is the rate at which dry mass of sediment passes a section of a stream or is the quantity of sediment, as measured by dry mass or volume, that passes a section in a given time. It is calculated in units of tons per day as follows: concentrations (mg/L) x discharge (ft3/s) x 0.0027. Suspended-sediment load is a general term that refers to material in suspension. It is not synonymous with either 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, as measured by dry mass or volume, that passes a section during a given time. Total-sediment load or total load is a term which refers to the total sediment (bed load plus suspended- sediment load) that is in transport. It is not synonymous with total-sediment discharge. 7-day 10-year low flow (7Q10) is the discharge at the 10-year recurrence interval taken from a frequency curve of annual values of the lowest mean discharge for 7 consecutive days (the 7-day low flow). 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 electric 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 about 65 percent of the specific conductance (in micromhos). 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. Stage-discharge relation is the relation between gage height (stage) and volume of water per unit of time, flowing in a channel. Streamfiow 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. Natural substrate refers to any naturally occurring emersed or submersed solid surface, such as a rock or tree, 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. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 Surface area of a lake is that area outlined on the latest U.S.G.S. topographic map as the boundary of the lake and measured by a planimeter in acres. In localities not covered by topographic maps, the areas are computed from the best maps available at the time planimetered. All areas shown are those for the stage when the planimetered map was made. Surficial bed material is that part (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 the total concentration 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 water- suspended sediment sample that is retained on a 0.45 um 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 representative water-suspended sediment sample that is retained on a 0.45 um membrane filter. 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 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. 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........................Arthopoda Class...........................Insecta Order...........................Ephemeroptera Family.........................Ephemeridae Genus..........................Hexagenia Species........................Hexagenia limbata Thermograph is an instrument that continuously records variations of temperature on a chart. The more general term "temperature recorder" is used in the table heading and refers to any instrument that records temperature whether on a chart, a tape, or any other medium. 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 indicates 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. 4 0 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1995 Tons per day (T/DAY) is the quantity of a substance in solution or suspension that passes a stream section during a 24-hour period. Total is the total amount of a given constituent in a representative water-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 water-suspended sediment mixture and that the analytical method determined all of the constituent in the sample.) Total discharge is the total quantity of any individual constituent, as measured by dry mass or volume, that passes through a stream cross-section per unit of time. This term needs to be qualified, such as "total sediment discharge," "total chloride discharge," and so on. Total, recoverable is the amount of a given constituent that is in solution after a representative water-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 paniculate 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. 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 precipitations stations. The purpose of the precipitation stations is to provide an estimate sufficient for hydrologic studies of the tritium input to the United States. Water year in 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, 1980, is called the "1980 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. WSP is used as an abbreviation for "Water-Supply Paper" in references to previously published reports. 41 PUBLICATIONS ON TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS The U.S. Geological Survey 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 sections 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. Geological Survey, Branch of Information Services, Box 25286, Federal Center, Denver, Colorado 80225 (authorized agent of the Superintendent of Documents, Government Printing Office). Prepayment is required. Remittance should be sent by 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 "U.S. Geological Survey Techniques of Water-Resources Investigations." 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, Chapter Dl. 1975. 65 pages. 1-D2. Guidelines for collection and field analysis of ground-water samples for selected unstable constituents, by W. W. Wood: USGS--TWRI Book 1, Chapter D2. 1976. 24 pages. 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, Chapter Dl. 1974. 116 pages. 2-D2. Application of seismic-refraction techniques to hydrologic studies, by F. P. Haeni: USGS--TWRI Book 2, Chapter D2. 1988. 86 pages. 2-E1. Application of borehole geophysics to water-resources investigations, by W. S. Keys and L.M. MacCary: USGS--TWRI Book 2, Chapter El. 1971. 126 pages. 2-E2. Borehole geophysics applied to ground-water investigations, by W. S. Keys: USGS--TWRI Book 2, Chapter E2. 1990. 150 pages. 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, Chapter Fl. 1989. 97 pages. 3-A1. General field and office procedures for indirect discharge measurements, by M. A. Benson and Tate Dalrymple: USGS--TWRI Book 3, Chapter Al. 1967. 30 pages. 3-A2. Measurement of peak discharge by the slope-area method, by Tate Dalrymple and M. A. Benson: USGS--TWRI Book 3, Chapter A2. 1967. 12 pages. 3-A3. Measurement of peak discharge at culverts by indirect methods, by G. L. Bodhaine: USGS--TWRI Book 3, Chapter A3. 1968. 60 pages. 3-A4. Measurement of peak discharge at width contractions by indirect methods, by H. F. Matthai: USGS-TWRI Book 3, Chapter A4. 1967. 44 pages. 3-A5. Measurement of peak discharge at dams by indirect methods, by Harry Hulsing: USGS--TWRI Book 3. Chapter A5. 1967. 29 pages. 42 3-A6. General procedure for gaging streams, by R. W. Carter and Jacob Davidian: USGS--TWRI Book 3, Chapter A6. 1968. 13 pages. 3-A7. Stage measurement at gaging stations, by T. J. Buchanan and W. P. Somers: USGS--TWRI Book 3, Chapter A7. 1968. 28 pages. 3-A8. Discharge measurements at gaging stations, by T. J. Buchanan and W. P. Somers: USGS--TWRI Book 3, Chapter A8. 1969. 65 pages. 3-A9. Measurement of time of travel in streams by dye tracing, by P. A. Kilpatrick and J. P. Wilson, Jr.: USGS--TWRI Book 3, Chapter A9. 1989. 27 pages. 3-A10. Discharge ratings at gaging stations, by E. J. Kennedy: USGS--TWRI Book 3, Chapter A10. 1984. 59 pages. 3-A11. Measurement of discharge by the moving-boat method, by G. F. Smoot and C. E. Novak: USGS—TWRI Book 3, Chapter All. 1969. 22 pages. 3-A12. Pluorometric procedures for dye tracing, Revised, by J. P. Wilson, Jr., E. D. Cobb, and F. A. Kilpatrick: USGS- -TWRI Book 3, Chapter A12. 1986. 34 pages. 3-A13. Computation of continuous records of streamflow, by E. J. Kennedy: USGS—TWRI Book 3, Chapter A13. 1983. 53 pages. 3-A14. Use of flumes in measuring discharge, by F. A. Kilpatrick and V. R. Schneider: USGS--TWRI Book 3, Chapter A14. 1983. 46 pages. 3-A15. Computation of water-surface profiles in open channels, by Jacob Davidian: USGS—TWRI Book 3, Chapter A15. 1984. 48 pages. 3-A16. Measurement of discharge using tracers, by F. A. Kilpatrick and E. D. Cobb: USGS--TWRI Book 3, Chapter A16. 1985. 52 pages. 3-A17. Acoustic velocity meter systems, by Antonius Laenen: USGS--TWRI Book 3, Chapter A17. 1985. 38 pages. 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, Chapter A18. 1989. 52 pages. 3-A19. Levels at streamflow gaging stations, by E.J. Kennedy: USGS—TWRI Book 3, Chapter A19. 1990. 31 pages. 3-A20. Simulation of soluable waste transport and buildup in surface waters using tracers, by P. A. Kilpatrick: USGS--TWRI Book 3, Chapter A20. 1993. 38 pages. 3-A21 Stream-gaging cableways, by C. Russell Wagner: USGS--TWRI Book 3, Chapter A21. 1995. 56 pages. 3-B1. Aquifer-test design, observation, and data analysis, by R. W. Stallman: USGS--TWRI Book 3, Chapter Bl. 1971. 26 pages. 3-B2. Introduction to ground-water hydraulics, a programed text for self-instruction, by G. D. Bennett: USGS-- TWRI Book 3, Chapter B2. 1976. 172 pages. 3-B3. Type curves for selected problems of flow to wells in confined aquifers, by J. E. Reed: USGS--TWRI Book 3, Chapter B3. 1980. 106 pages. 43 3-B4. Regression modeling of ground-water flow, by R. L. Cooley and R. L. Naff: USGS--TWRI Book 3, Chapter B4. 1990. 232 pages. 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, Chapter B4. 1993. 8 pages. 3-B5. Definition of boundary and initial conditions in the analysis of saturated ground-water flow systems--An introduction, by O. L. Franks, T. E. Reilly, and G. D. Bennett: USGS--TWRI Book 3, Chapter B5. 1987. 15 pages. 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, Chapter B6. 1987. 28 pages. 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, Chapter B7. 1992. 190 pages. 3-C1. Fluvial sediment concepts, by H. P. Guy: USGS—TWRI Book 3, Chapter Cl. 1970. 55 pages. 3-C2. Field methods for measurement of fluvial sediment, by H. P. Guy and V. W. Norman: USGS--TWRI Book 3, Chapter C2. 1970. 59 pages. 3-C3. Computation of fluvial-sediment discharge, by George Porterfield: USGS--TWRI Book 3, Chapter C3. 1972. 66 pages. 4-A1. Some statistical tools in hydrology, by H. C. Riggs: USGS--TWRI Book 4, Chapter Al. 1968. 39 pages. 4-A2. Frequency curves, by H. C. Riggs: USGS--TWRI Book 4, Chapter A2. 1968. 15 pages. 4-B1. Low-flow investigations, by H. C. Riggs: USGS—TWRI Book 4, Chapter Bl. 1972. 18 pages. 4-B2. Storage analyses for water supply, by H. C. Riggs and C. H. Hardison: USGS—TWRI Book 4, Chapter B2. 1973. 20 pages. 4-B3. Regional analyses of streamflow characteristics, by H. C. Riggs: USGS—TWRI Book 4, Chapter B3. 1973. 15 pages. 4-D1. Computation of rate and volume of stream depletion by wells, by C. T. Jenkins: USGS--TWRI Book 4, Chapter Dl. 1970. 17 pages. 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, Chapter Al. 1989. 545 pages. 5-A2. Determination of minor elements in water by emission spectroscopy, by P. R. Barnett and E. C. Mallory, Jr.: USGS—TWRI Book 5, Chapter A2. 1971. 31 pages. 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, Chapter A3. 1987. 80 pages. 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, Chapter A4. 1989. 363 pages. 44 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, Chapter A5. 1977. 95 pages. 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, Chapter A6. 1982. 181 pages. 5-C1. Laboratory theory and methods for sediment analysis, by H. P. Guy: USGS--TWRI Book 5, Chapter Cl. 1969. 58 pages. 6-A1. A modular three-dimensional finite-difference ground-water flow model, by M. G. McDonald and A. W. Harbaugh: USGS--TWRI Book 6, Chapter Al. 1988. 586 pages. 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, Chapter A2. 1991. 68 pages. 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, Chapter A3. 1993. 136 pages 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, Chapter A4. 1992. 108 pages. 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, Chapter A5, 1993. 243 pages. 7-Cl. Finite difference model for aquifer simulation in two dimensions with results of numerical experiments, by P. C. Trescott, G. F. Finder, and S. P. Larson: USGS--TWRI Book 7, Chapter Cl. 1976. 116 pages. 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, Chapter C2. 1978. 90 pages. 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, Chapter C3. 1981. 110 pages. 8-A1. Methods of measuring water levels in deep wells, by M. S. Garber and F. C. Koopman: USGS--TWRI Book 8, Chapter Al. 1968. 23 pages. 8-A2. Installation and service manual for U.S. Geological Survey manometers, by J. D. Craig: USGS--TWRI Book 8, Chapter A2. 1983. 57 pages. 8-B2. Calibration and maintenance of vertical-axis type current meters, by G. F. Smoot and C. E. Novak: USGS--TWRI Book 8, Chapter B2. 1968. 15 pages. 45 46 THIS PAGE WAS LEFT BLANK INTENTIONALLY ATLANTIC OCEAN ***« or «**<** d* V <£ A&Qi&ts &&ft*ft ,0105 V010720 EXPLANATION SURFACE-WATER STATION AND NUMBER QUALITY-OF-WATER STATION AND NUMBER QUALITY-OF-WATER PARTIAL RECORD STATION AND NUMBER LAKE-ELEVATION STATION AND NUMBER WELL AND WELL NUMBER -Mao J&*1 Jw*« «,««w Figure 13.--Rio Guajataca basin. RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR LOCATION.--Lat 18°18'01", long 66°52'24", Hydrologie Unit 21010001 at bridge on Highway 111, 0.1 mi (0.2 km) upstream from Quebrada Anon, and 0.4 mi (0.6 km) east of Lares. DRAINAGE AREA.--3.16 mi 9 (8.18 km9 ). WATER-DISCHARGE RECORDS PERIOD OP 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 Hay 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 in), 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT MAY JON JUL SEP 1 6.3 11 2 18 5.0 3 7.9 3.7 4 4.8 4.1 5 4.0 3.4 6 3.6 3.2 7 3.6 3.2 8 12 3.0 9 4.5 3.0 10 3.2 2.8 11 15 8.8 12 8.2 3.9 13 6.9 2.8 14 33 2.8 15 12 2.8 16 7.2 2.8 17 9.0 12 18 16 4.6 19 8.4 3.3 20 13 3.1 21 7.1 2.4 22 6.2 2.1 23 5.6 2.0 24 5.0 1.7 25 4.9 5.6 26 5.7 2.2 27 13 1.8 28 7.6 1.7 29 4.5 1.9 30 4.3 1.7 31 3.6 —— TOTAL 264.1 112.4 MEAN 8.52 3.75 MAX 33 12 MIN 3.2 1.7 AC-FT 524 223 CFSM 2.70 1.19 IN. 3.11 1.32 STATISTICS OF MONTHLY MEAN MEAN 15.9 8.37 MAX 33.7 16.7 (WY) 1991 1971 MIN 8.52 3.75 (WY) 1995 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 6.7 14 2.8 2.0 1.8 1.6 1.8 1.9 1.5 1.4 1.5 7.3 2.5 1.7 1.7 2.5 7.4 3.8 1.9 1.8 1.5 1.4 1.3 1.2 1.3 7.9 2.1 1.7 1.2 1.9 1.2 90.3 2.91 14 1.2 179 .92 1.06 DATA 3.70 7.31 1971 1.35 1991 FOR 1.4 1.8 1.3 1.3 1.4 1.4 1.3 1.3 1.4 1.3 1.6 1.9 16 4.6 19 7.1 2.4 2.0 2.1 2.9 25 12 4.4 6.1 4.6 25 6.5 4.6 4.0 4.0 4.6 174.3 5.62 25 1.3 346 1.78 2.05 FOR WATER 2.90 6.83 1971 .66 1991 3.4 3.7 3.3 3.0 3.0 2.8 3.5 2.9 2.7 2.4 2.3 2.1 2.4 2.4 2.1 2.0 1.9 1.9 2.0 2.0 2.0 3.6 3.0 1.8 5.9 3.7 3.8 3.9 ___ ___ 79.5 2.84 5.9 1.8 158 .90 .94 YEARS 1969 2.13 5.37 1971 .93 1992 5.2 10 2.4 1.4 1.4 1.4 .98 13 3.2 10 3.5 2.7 3.3 3.0 2.4 2.1 2.5 1.6 1.6 1.5 1.4 1.7 1.3 1.4 1.3 1.3 1.2 1.4 1.1 1.1 1.2 87.58 2.83 13 .98 174 .89 1.03 - 1995 2.17 6.38 1971 .92 1994 1994 CALENDAR YEAR 1404. 3. 37 . . 2790 1. 16. 9. 1. . 09 85 May 17 56 Mar 20 €7 Mar 14 22 53 5 7 79 1.2 1.2 1.2 1.1 1.0 1.1 1.0 1.1 1.8 1.5 1.1 3.3 1.0 1.0 1.2 .89 1.1 1.1 .94 .93 .92 1.1 1.0 .98 .91 1.0 1.0 1.3 1.0 .96 ___ 34.93 1.16 3.3 .89 69 .37 .41 1.0 .98 .93 1.0 29 9.6 2.7 14 15 28 29 10 45 66 36 26 19 15 33 38 22 16 12 10 11 15 38 22 15 13 34 627.21 20.2 66 .93 1240 6.40 7.38 21 14 26 16 30 18 22 23 28 36 23 17 14 16 24 28 16 12 14 15 10 8.6 8.1 7.7 7.4 7.2 7.4 7.8 6.9 6.7 490.8 16.4 36 6.7 974 5.18 5.78 6.6 6.5 10 6.8 11 9.3 11 7.9 7.3 6.9 6.9 11 7.4 6.4 6.2 5.4 8.6 5.6 5.5 5.4 5.5 5.7 8.4 5.1 4.5 4.2 4.2 5.5 4.2 3.7 8.8 211.5 6.82 11 3.7 420 2.16 2.49 4.3 14 11 6.8 5.9 6.9 5.5 5.3 6.3 5.6 5.0 4.2 4.8 5.1 4.1 22 7.2 5.1 13 4.9 4.1 3.5 3.2 6.1 5.6 5.3 5.7 4.8 4.3 3.9 5.8 199.3 6.43 22 3.2 395 2.03 2.35 4.3 4.3 6.6 4.6 14 27 43 9.9 15 7.4 9.4 5.7 4.4 4.0 15 63 18 8.7 6.7 6.3 5.5 7.2 26 9.1 5.6 24 30 19 11 15 429.7 14.3 63 4.0 852 4. S3 5.06 , BY WATER YEAR (WY) 3.51 7.63 1993 1.09 1994 FOR 1995 2801 7 66 451 10 5560 2 32 18 4 1 10.6 20.2 1995 3.66 1992 WATER YEAR .62 .68 May 14 .89 Apr 16 .97 Apr 19 Oct 14 .91 Oct 14 .43 .98 .5 .2 7.85 16.4 1995 3.18 1992 4.27 9.85 1969 2.01 1994 WATER 6 e 4 216 5300 21 4420 1 26 14 3 5.47 9.88 1991 3.34 1970 YJARS 1969 .10 .05 .13 .47 .51 .30 .93 .24 .4 .94 Oct Jan Jan Oct Oct 10.8 15.7 1990 5.95 1993 - 1995 1991 1994 7 1990 13 1991 9 1991 7 1990 7 1990 49 RIO GUAJATACA BASIN 50010500 RIO G0AJATACA AT LARES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18 8 18'01", long 66 852'24", at bridge on Highway 111 (km 32.9), 0.1 mi (0.2 km) upstream from Quebrada Anon, and 0.4 mi (0.6 km) northeast of Lares plaza. DRAINAGE AREA.--3.16 mi' (8.18 km 1 ). PERIOD OP RECORD.--Water years 1958-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 18. .. DEC 15. .. FEB 1995 16. .. APR 20. . . OUN 15. .. SEP 18. .. DATE OCT 1994 18. .. DEC 15. .. FEB 1995 16. .. APR 20. .. JUN 15. .. SEP 18. .. TIME 1515 1330 1020 1410 1345 1215 HARD- NESS TOTAL (MG/L AS CACO3) 85 -- -- 95 -- 100 SILICA, DATE OCT 1994 18. . . DEC 15. . . FBB 1995 16. .. APR 20... JUN 15. .. SEP 18. . . K • non-ideal DIS- SOLVED (MG/L AS SI02) 23 — -- 31 -- 28 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 10 1.5 2.3 1.1 11 8.5 CALCIUM DIS- SOLVED (MG/L AS CA) 26 -- __ 27 -- 32 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 128 -- __ 159 -- 160 SPE- CIFIC CON- DUCT- ANCE (US/CM) 218 265 238 247 224 252 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 4.9 — __ 6.6 -- 5.7 SOLIDS, DIS- SOLVED (TONS PER DAY) 3.50 — — 0.46 -- 3.67 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.6 7.7 7.3 7.5 7.6 6.7 SODIUM, DIS- SOLVED (MG/L AS NA) 8.6 -- __ 13 __ 11 RESIDUE TOTAL AT 105 DEG. C SUS- PENDED (MG/L) 32 13 11 12 10 14 TEMPER- ATURE WATER (DEG C) 23.0 22.0 21.0 23.5 24.0 25.0 SODIUM AD- SORP- TION RATIO 0.4 — — 0.6 __ 0.5 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.30 <0.20 0.20 <0.20 0.24 0.20 TUR- BID- ITY (NTU) 46 13 14 9.8 2.8 7.9 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.7 _- __ 2.3 __ 2.8 PHOS- PHORUS TOTAL (MG/L AS P) 0.070 0.070 0.080 0.050 0.030 0.090 OXYGEN, DIS- SOLVED (MG/L) 7.4 8.4 7.4 7.1 7.1 6.6 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 74 110 90 92 80 100 ARSENIC TOTAL (UG/L AS AS) 1 -- __ 1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 87 94 85 87 87 82 SULFIDE TOTAL (MG/L AS S) <0.5 -- __ <0.5 _- -~ BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 13 <10 14 <10 <10 <10 SULFATE DIS- SOLVED (MG/L AS S04) 9.8 -- — 11 — 10 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 20 — -- 30 — — COLI- FORM, FECAL, 0.45 UM-MF (COLS . / 100 ML) 5700 2700 3400 5100 K6200 K6200 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 9.0 -- _- 13 -- 11 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 27000 2000 2300 3600 3800 7200 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 -- -- <0.10 -- <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 -- -- 50 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR—CONTINUED WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 COPPER, IRON, TOTAL TOTAL RBCOV- RECOV- ERABLE ERABLE DATE OCT 1994 18. .. DEC 15. .. FEB 1995 16. .. APR 20. .. JUN 15. .. SEP 18. .. (UG/L (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, MERCURY TOTAL TOTAL RECOV- ERABLE RECOV- ERABLE (UG/L (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- CYANIDE ERABLE TOTAL (UG/L (MG/L MBTHY- LENE BLUE ACTIVE PHENOLS SUB- TOTAL AS CU) AS FE) AS PB) AS HN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) 1000 320 <1 50 50 <0.10 <0.10 <0.010 <0.010 STANCE (MG/L) <0.02 0.02 RIO GUAJATACA BASIN 50010800 LAGO GOAJATACA AT DAMSITE NEAR QUEBRADILLAS, PR LOCATION.--Lat 18°24'02", long 66°55'25", Hydrologie 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 mi 1 (63.71 km1 ) ELEVATION RECORDS PERIOD OP RECORD.--April 1995 to September 1995. 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) hight, 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 lenght 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, Isabels, Hoca, 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. EXTREMES OBSERVED FOR CURRENT PERIOD.--Maximum elevation, 643.45 ft (196.1 m), Sept. 29; minimum elevation, 620.43 ft (189.1 m). May 8. 51 Elevation, in feet 593 600 Capacity Table (based on data from Puerto Rico Electric Power Authority) Contents, in acre-feet Elevation, in feet 0 2,405 625 650 Contents, in acre-feet 15,295 36,403 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX MIN OCT DEC FEB APR MAY JUN JUL AUG SEP 625.54 625.37 625.19 625.12 624.98 624.82 624.95 624.82 624.63 624.45 624.28 624.09 623.92 623.74 623.56 623.36 623.18 622.98 622.78 622.59 622.40 622.23 622.04 621.84 621.66 --- ___ 621.45 621.23 621.01 620.83 620.82 620.73 620.53 621.14 621.69 622.77 624.42 625.32 631.58 635.35 636.82 638.03 638.52 638.90 639.58 639.74 639.52 639.09 638.63 638.35 638.21 638.21 639.37 639.55 639.44 638.99 639.70 639.74 620.53 639.84 639.58 639.31 638.94 638.83 638.97 639.78 639.85 640.01 640.04 640.25 640.07 639.52 A A A A A A A A A 638.96 638.61 638.24 638.08 638.01 637.94 637.86 637.90 ___ _-_ _-- 637.83 637.73 637.65 637.58 638.52 639.00 639.23 639.30 639.28 639.22 639.16 639.12 639.06 638.97 638.88 638.79 639.02 638.98 638.89 638.81 638.69 638.59 638.86 638.85 638.75 638.65 638.55 638.64 638.57 638.47 638.47 639.30 637.58 638.62 638.68 638.66 638.57 638.47 638.52 638.63 638.85 638.93 638.91 638.84 638.76 638.64 638.57 638.74 638.79 638.80 638.59 638.44 638.00 637.52 636.98 636.48 636.27 636.19 636.09 635.98 635.86 635.72 635.61 635.79 638.93 635.61 635.82 635.72 635.59 635.43 635.03 635.09 635.74 635.86 635.84 635.77 635.81 635.73 635.64 635.51 635.54 637.71 638.21 638.35 638.34 638.38 638.41 638.49 639.38 639.81 639.92 640.81 642.53 643.36 643.29 642.83 643.36 635.03 A No gage-height record 52 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 1994 TO SEPTEMBER 1995 DATE OCT 1994 25. .. DEC 09. .. FEE 1995 16... APR 26.. . JUN 22. .. SEP 19... DATE OCT 1994 25... DEC 09. .. FEE 1995 16... APR 26. .. JUN 22. . . SEP 19... TIME 1630 1405 1515 0745 1445 1305 HARD- NESS TOTAL (HG/L AS CACO3) 140 -- — 130 — 150 SILICA, DATE OCT 1994 25. .. DEC 09. .. FEE 1995 16... APR 26. .. JUN 22. .. SEP 19. .. * • Discharge K • non- ideal E - Estimated DIS- SOLVED (MG/L AS SI02) 6.3 — __ 6.3 __ 6.9 values count DIS- CHARGE, INST. CUBIC FEET PER SECOND *65 *65 •70 •65 *65 *60 CALCIUM DIS- SOLVED (MG/L AS CA) 51 __ __ 47 __ 55 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 167 __ -- 155 __ 187 provided SPE- CIFIC CON- DUCT- ANCE (US/CM) 295 305 295 269 305 322 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 3.5 — — 3.6 __ 3.3 SOLIDS, DIS- SOLVED (TONS PER DAY) E 29.3 __ — E 27.2 — E 30.3 by Puerto PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.3 7.7 7.5 7.7 7.9 6.2 SODIUM, DIS- SOLVED (MG/L AS NA) 4.9 __ __ 6.0 __ 5.3 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 5 <1 5 2 <1 8 Rico El« TEMPER- ATURE WATER (DEG C) 25.0 25.0 25.0 27.0 25.0 27.5 SODIUM AD- SORP- TION RATIO 0.2 — __ 0.2 __ 0.2 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.30 0.30 0.30 0.30 0.27 0.76 metric and TUR- BID- ITY (NTU) 1.6 0.70 0.60 1.2 1.2 1.7 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 1.8 __ __ 2.0 __ 1.9 PHOS- PHORUS TOTAL (MG/L AS P) 0.040 0.030 <0.010 <0.010 0.020 0.020 OXYGEN, DIS- SOLVED (MG/L) 0.3 0.6 3.2 5.6 1.1 2.0 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 140 150 140 120 140 170 ARSENIC TOTAL (UG/L AS AS) 2 __ -- <1 __ -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 4 7 39 72 14 26 SULFIDE TOTAL (MG/L AS S) <0.5 __ __ <0.5 __ -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) 100 __ __ <100 __ -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 16 13 <10 11 <10 <10 SULFATE DIS- SOLVED (MG/L AS S04) 8.7 __ __ 8.4 __ 5.5 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 20 _- __ 20 __ -- COLI- FORM, FECAL, 0.45 UH-MF (COLS./ 100 ML) 48 K27 K2 K4 K22 K66 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 6.6 __ __ 9.4 __ 7.2 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 _- -- <1 __ -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K25 Kll K2 K5 K6 K20 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 __ __ <0.10 __ <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 — -- <1 — — Power Authority. RIO GUAJATACA BASIN 50011000 CANAL PRINCIPAL DE DIVERSIONES AT LAGO DE GOAJATACA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 53 DATE OCT 1994 25. .. DEC 09. . . FEB 1995 16. .. APR 26. .. JUN 22. .. SEP 19. .. COPPER, TOTAL RECOV- ERABLE (OG/L AS CO) <10 — — 10 -- -- IRON, TOTAL RECOV- ERABLE (OG/L AS FE) 60 -. -. 740 -- -- LEAD, TOTAL RECOV- ERABLE (DG/L AS PB) <1 — __ <1 -- -- MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MM) 60 __ __ 60 -- -- MERCURY TOTAL RECOV- ERABLE (OG/L AS HG) <0.10 __ __ <0.10 -- — SELE- NIUM, TOTAL (OG/L AS SE) <1 __ __ <1 -- -- SILVER, TOTAL RECOV- ERABLE (OG/L AS AG) <1 -- — <1 -- -- ZINC, TOTAL RECOV- ERABLE (OG/L AS ZN) <10 -- ._ <10 -- -- CYANIDE TOTAL PHENOLS (MG/L TOTAL AS CN) (OG/L) <0.010 <1 __ __ <0.010 <1 __ __ METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) <0.02 — -- 0.05 — -- 54 RIO OUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MODTH NEAR QUEBRADILLAS, PR--Continued 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) upstree 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 OP RECORD.—Water years 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 27. .. JAN 1995 12. .. FEB 17. .. APR 26. .. JTJN 23. .. SEP 20. . . DATE OCT 1994 27. .. JAN 1995 12. .. FEB 17. . . APR 26. .. JTJN 23. .. SEP 20. .. DATE OCT 1994 27. .. JAN 1995 12. .. FEB 17. .. APR 26. .. JUN 23. . . SEP 20... TIME 0800 1000 0925 1100 0715 0715 HARD- NESS TOTAL (HG/L AS CAC03) 200 -- -- 250 -- 220 SILICA, DIS- SOLVED (MG/L AS SI02) 7.9 -- -- 6.1 -- 6.9 DIS- CHARGE, INST. CUBIC FEET PER SECOND 31 14 12 5.3 221 * CALCIUM DIS- SOLVED (MG/L AS CA) 70 -- -- 83 -- 69 SOLIDS , SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 232 -- -- 315 -- 408 SPE- CIFIC CON- DUCT- ANCE (US /CM) 403 483 447 594 315 810 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 5.1 __ — 10 __ 12 SOLIDS, DIS- SOLVED (TONS PER DAY) 19.4 -- -- 4.50 -- -- PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.4 7.5 7.3 7.7 8.2 7.8 SODIUM, DIS- SOLVED (MG/L AS NA) 9.7 __ __ 24 __ 63 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 4 3 <1 4 3 69 TEMPER- ATURE WATER (DEG C) 24.0 22.5 23.0 25.5 25.0 26.0 SODIUM AD- SORP- TION RATIO 0.3 __ — 0.7 — 2 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 <0.20 <0.20 <0.20 <0.20 <0.20 TUR- BID- ITY (NTU) 4.0 0.70 0.70 0.50 7.4 1.5 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 1.3 __ __ 1.2 __ 3.4 PHOS- PHORUS TOTAL (MG/L AS P) 0.010. 0.030 <0.010 <0.010 0.020 0.020 OXYGEN, DIS- SOLVED (MG/L) 5.8 6.0 5.3 6.1 7.2 3.8 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 190 200 190 230 150 190 ARSENIC TOTAL (UG/L AS AS) <1 — -- <1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 68 68 61 74 87 46 SULFIDE TOTAL (MG/L AS S) <0.5 __ __ <0.5 __ -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 <10 10 <10 <10 12 SULFATE DIS- SOLVED (MG/L AS SO4) 7.7 __ -_ 7.1 __ 20 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 10 -- -- 50 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS. / 100 ML) K140 K72 K30 K80 420 K120 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 16 __ __ 46 __ 120 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 510 210 K14 80 710 240 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 __ __ <0.10 __ <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 — -- 2 -- -- K = non-ideal count * a Sample was collected at hwy #2, 2 miles downstream of regular sampling site. 55 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR--Continued WATER-QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 27. .. JAN 1995 12 ... FEB 17. . . APR 26... JUN 23. . . SEP 20. . . COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 IRON, TOTAL RECOV- ERABLE (UG/L AS FE) 100 LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) <x MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 20 MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 SELE- NIUM, TOTAL (UG/L AS SE) <x SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <:l ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) <10 CYANIDE TOTAL (MG/L AS CN) <0.010 PHENOLS TOTAL (OG/L) <x METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) <0.02 70 20 <0.10 <0.010 <0.02 56 THIS PAGE WAS LEFT BLANK INTENTIONALLY ATLANTIC OCEAN 57 ™,——/"HAT IL L Q * 0157 ARECfBO 7 ?X / v< ./ S\ ^»- A / V I ; "/ ' : J,1 |f' f > Ri'» ?• .if -A 4 #(;;:; V ' ......J EXPLANATION Aoi48 SURFACE-WATER STATION AND NUMBER s\.*i **»£«"• J» „ 01 23456 KHX)METERS 01234 MILES Figure 14.--Rio Camuy basin. 58 RIO CAMtTY BASIN 50014600 RIO CAMUY AT TRES PUEBLOS SINKHOLE, PR LOCATION.—Lat 18°20'42", long 66°49'29", Hydrologie Unit 21010002, at Parque de las Cave mas del Rio Camuy, 1.8 mi (2.9 km) southeast from Escuela Segunda Unidad de Santiago Palmer, 4.7 mi (7.6 km) west from Observatorio de Arecibo and 4.8 mi (7.7 km) northeast from Plaza de Lares. DRAINAGE AREA.—Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.—June 1990 to current year. GAGE.—Water-stage recorder and crest-stage gage. Datum of gage is 612.21 ft (186.602 m), above mean sea level. REMARKS.--Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY NOV DEC JAN FEB MAR MAY JUL AUG SEP 1 90 56 2 75 57 3 72 46 4 47 45 5 47 44 6 46 41 7 46 39 8 86 39 9 116 38 10 161 38 11 156 41 12 178 44 13 116 36 14 224 34 15 161 33 16 83 33 17 69 55 18 117 58 19 82 43 20 171 66 21 103 47 22 87 38 23 67 35 24 57 34 25 52 77 26 51 67 27 62 48 28 83 42 29 56 40 30 51 39 31 48 —— TOTAL 2862 1353 MEAN 92.3 45.1 MAX 224 77 MIN 46 33 STATISTICS OF MONTHLY MEAN MEAN 83.9 49.0 MAX 112 55.9 (WY) 1991 1992 MIN 64.5 41.4 (WY) 1993 1994 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM ANNUAL RUNOFF (AC- FT) INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 38 60 50 39 36 35 33 33 33 31 30 29 30 29 28 28 47 67 34 55 34 33 30 28 28 47 46 34 31 29 29 1134 36.6 67 28 29 27 26 26 25 25 24 23 23 23 23 22 29 49 47 87 33 28 26 24 60 110 40 31 32 96 68 40 34 31 29 1190 38.4 110 22 DATA FOR WATER 34.2 42.6 1993 29.8 1991 FOR 27.8 38.4 1995 21.6 1991 27 26 25 25 25 24 24 25 23 22 22 21 21 21 20 20 19 19 18 19 19 65 60 32 66 67 77 50 ___ —— 882 31.5 77 18 YEARS 1990 23.3 31.5 1995 15.4 1994 78 67 66 45 46 51 43 56 57 44 43 41 39 44 40 35 32 31 30 29 28 27 27 27 26 25 26 26 25 24 24 1202 38.8 78 24 - 1995 25.1 38.8 1995 12.9 1994 1994 CALENDAR YEAR 12250 33. 224 10 11 24300 67 23 12 6 Oct 14 May 5 Apr 29 23 23 23 22 22 22 21 20 26 30 22 32 23 19 18 18 29 19 18 17 17 16 16 16 15 18 16 16 16 15 —— 608 20.3 32 15 15 14 14 15 102 114 50 66 159 208 237 196 253 437 346 259 200 193 261 241 159 118 102 92 105 124 126 130 98 93 212 4739 153 437 14 193 129 172 158 278 232 201 258 260 236 161 129 113 103 137 182 120 101 93 150 188 123 98 91 85 81 78 76 79 69 —— 4374 146 278 69 67 63 64 65 129 127 78 71 63 58 55 53 53 52 50 45 43 50 44 40 39 41 39 60 40 36 35 36 38 34 33 1701 54.9 129 33 50 38 53 38 35 47 38 33 38 39 34 31 30 76 56 89 84 64 94 79 55 49 44 40 39 37 37 35 34 33 32 1481 47.8 94 30 32 31 38 42 43 50 200 168 77 67 65 73 62 51 65 420 198 120 91 79 78 80 202 182 103 145 267 317 261 158 ___ 3765 125 420 31 , BY WATER YEAR (WY) 33.3 47.3 1993 12.5 1994 FOR 1995 25291 69. 437 14 15 50160 965 11. 14 161 44 22 83.7 153 1995 36.1 1994 WATER YEAR 3 May 14 May 2 Apr 28 May 13 80 May 13 May 4 61.7 146 1995 32.1 1991 34.4 54.9 1995 18.4 1994 WATER 48 69 30 437 10 11 1030 12 13 90 35 17 41.8 66.0 1991 24.7 1993 YEARS 1990 - .6 .3 .4 May 14 May 5 Apr 29 Oct 31 .42 Oct 31 Mar 23 72.9 125 1995 44.6 1994 1995 1995 1994 1995 1994 1994 1991 1991 1993 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) aoutheaat of achool at Santiago, 0.9 mi (1.4 km) northweat from Eacuela Manuel A. Rivera at Bayaney and 9.1 mi (14.6 km) upatream from mouth. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--Hay 1984 to current year. GAGE.--Water-atage recorder. Elevation of gage ia 341 ft (104 m), from topographic map. REMARKS.--Recorda fair. Gage-height and precipitation satellite telemetry at atation. 59 DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER DAILY MEAN VALUES 1995 DAY DEC FEB MAR APR MAY AUG 1 124 67 2 96 78 3 104 66 4 73 62 5 67 60 6 77 57 7 68 54 8 103 54 9 184 55 10 387 54 11 322 55 12 260 61 13 218 53 14 465 49 15 278 47 16 136 46 17 109 51 18 156 63 19 131 SB 20 327 75 21 264 66 22 220 57 23 127 49 24 99 47 25 90 81 26 87 86 27 81 67 28 112 59 29 76 52 30 70 51 31 67 —— TOTAL 4998 1800 MEAN 161 60.0 MAX 485 86 MIN 67 46 STATISTICS OF MONTHLY MEAN MEAN 199 114 MAX 427 244 (WY) 1966 1986 MIN 81.6 60.0 (WY) 1988 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 48 156 90 64 57 52 46 53 49 46 44 43 43 42 41 43 53 95 57 62 55 46 42 40 39 41 74 54 44 41 40 1702 54.9 156 39 DATA 67.4 97.4 1988 49.7 1989 FOR 40 39 37 37 37 37 38 37 37 38 37 36 60 87 57 123 61 44 38 36 50 146 60 48 43 126 93 61 55 45 42 1725 55.6 146 36 FOR WATER 49.2 BO. 9 1988 33.1 1991 40 36 37 36 36 35 35 37 34 34 34 33 32 31 31 31 31 30 30 30 31 64 93 51 63 91 112 71 ___ ___ 1251 44.7 112 30 YEARS 1984 45.0 78.3 1987 29.2 1992 97 99 B9 64 57 67 58 5B 82 5B 59 57 54 57 59 53 45 43 43 42 41 40 39 36 36 35 34 34 34 33 33 163B 52.8 99 33 - 1995 46.0 66.0 1992 23.7 1994 1994 CALENDAR YEAR 21766 59. 562 16 17 120 37 26 6 May 17 Mar IB Mar 16 33 32 32 31 31 31 30 29 32 45 33 54 39 34 31 31 42 32 30 30 29 2B 2B 27 27 30 29 30 28 28 --- 966 32.2 54 27 28 27 27 27 116 152 58 56 191 326 399 292 413 1080 59B 387 294 317 414 350 219 149 123 121 130 270 244 230 193 166 435 7832 253 10BO 27 332 190 253 319 639 430 353 466 520 430 257 204 170 175 193 258 166 138 154 204 250 156 120 110 102 96 92 92 94 83 7046 235 639 83 78 76 76 BO 150 180 93 85 78 72 68 68 68 69 71 63 66 73 64 61 60 60 61 76 67 62 55 56 60 58 55 2309 74.5 1BO 55 70 6B 71 62 56 161 95 117 88 72 62 56 53 95 B6 104 109 84 128 106 157 102 78 72 68 64 61 5B 55 53 54 2565 62.7 161 53 55 51 50 68 61 264 414 191 100 87 76 91 78 70 65 1270 333 223 156 132 164 134 574 349 167 197 460 694 507 232 7333 244 1270 50 , BY WATER YEAR (WY) 96.9 202 1986 28.0 1994 FOR 1995 41165 113 1270 27 2B 2660 12 26 262 64 33 1B9 624 1986 43.2 1989 WATER YEAR Sep 16 Apr 24 Apr 2B Hay 14 .97 May 14 Hay 4 112 235 1995 52.3 1994 75.9 109 1989 38.8 1994 WATER 103 179 61 3B20 16 17 6450 17 15 202 67 33 67.2 135 1989 47.9 1993 YEARS 1984 - .5 Oct 7 Mar 18 Mar 16 Oct 7 .66 Oct 7 Mar 22 155 273 1964 88.7 1994 1995 1986 1994 1985 1994 1994 1965 1985 1994 60 RIO CAMUY BASIN 50015700 RIO CAMUY NEAR HATILLO, PR LOCATION.--Lat 18°27'44 11 , long 66°49'56", Hydrologic Unit 21010002, 1.8 mi (2.9 km) southwest of Hatillo plaza, and 1.8 mi (2.9 km) southeast of Camuy plaza, 1.2 mi (1.9 km) south of Planta de Purificacion, and 3.3 mi (5.5 km) upstream from Atlantic Ocean. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS PERIOD OP RECORD.--June 1984 to current year. GAGE.--Water-stage recorder. Elevation of gage is 13 ft (4 m), from topographic map. REMARKS.--Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC PEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY NOV DEC PEB MAR APR AUG 1 161 68 2 97 82 3 131 68 4 84 64 5 71 62 6 86 60 7 74 56 8 94 57 9 249 60 10 611 63 11 551 64 12 444 71 13 335 60 14 798 54 15 639 52 16 175 50 17 128 50 18 214 93 19 171 63 20 567 82 21 402 82 22 432 67 23 191 55 24 129 52 25 104 66 26 102 118 27 89 89 28 126 66 29 83 60 30 74 63 31 70 - — TOTAL 7482 1997 MEAN 241 66.6 MAX 798 118 MIN 70 50 STATISTICS OP MONTHLY MEAN MEAN 328 170 MAX 735 439 (WY) 1986 1986 MIN 116 66.6 (WY) 1988 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN -DAY MINIMUM INSTANTANEOUS PEAK PLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW PLOW 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 58 208 156 82 73 63 58 71 65 58 54 52 51 50 47 46 65 100 61 66 61 52 48 46 45 45 72 56 46 43 42 2040 65.8 208 42 DATA 88.0 176 1993 51.4 1992 POR 43 41 40 41 40 40 39 39 39 39 39 38 38 120 58 131 62 49 43 42 40 177 63 50 44 128 122 67 58 48 44 1862 60.1 177 38 POR WATER 62.5 131 1988 46.2 1989 42 40 40 39 38 38 38 39 37 36 36 36 35 35 34 34 33 32 33 34 34 35 143 54 44 122 159 96 ___ --- 1416 50.6 159 32 YEARS 1984 62.5 134 1987 34.1 1992 76 186 152 79 67 75 65 57 90 59 60 58 56 64 70 59 50 47 47 44 42 41 41 40 39 38 37 37 37 37 35 1885 60.8 186 35 - 1995 63.7 88.1 1992 33.1 1994 1994 CALENDAR YEAR 28589 78. 1050 26 27 160 44 30 3 May 17 May 6 Apr 8 35 34 34 33 31 32 31 30 32 47 35 62 48 36 32 33 42 34 32 32 31 32 31 29 29 32 31 31 31 29 —— 1031 34.4 62 29 29 29 28 28 42 311 68 54 183 386 666 693 308 2940 1390 740 517 363 752 573 302 169 137 134 146 348 365 432 282 240 582 13237 427 2940 28 640 230 322 476 871 1040 502 967 1090 1220 394 254 196 204 214 355 202 148 155 199 343 172 122 107 99 93 89 88 95 83 —— 10970 366 1220 83 81 78 76 82 132 247 101 89 84 80 77 76 75 75 79 70 68 78 70 67 65 65 65 77 67 65 62 62 67 63 60 2503 80.7 247 60 70 71 75 69 63 204 178 136 175 92 75 70 64 97 141 93 154 94 154 147 225 192 102 98 95 81 76 73 67 64 65 3360 108 225 63 74 63 61 77 68 447 796 402 129 104 91 104 91 79 77 3150 907 339 230 167 225 194 1070 1010 225 204 880 1530 1300 337 14431 481 3150 61 , BY WATER YEAR (WY) 175 411 1986 30.7 1994 POR 1995 62214 170 3150 28 29 5950 20 397 70 35 366 1586 1986 59.5 1989 WATER YEAR Sep 16 Hay 3 Apr 28 May 14 .18 May 14 159 366 1995 58.5 1994 98.7 161 1990 44.0 1994 WATER 160 335 76 8150 25 27 10700 27 25 309 78 40 112 180 1989 54.8 1993 YEARS 1984 .7 Oct May Apr Oct .75 Oct May 226 481 1995 117 1992 - 1995 1986 1994 7 1985 30 1990 8 1994 7 1985 7 1985 6 1994 ^•x 6A»CES-OW£TA \ c \ 023 \ I 1 027750:' A<4M~S* ( l<t */ */ <* 9o*3ney f Oc^"-™1^ <xrs\ 027250 / « \ ! T S 027090, undurjr-. ^'020050^*] A. \ B .*T'-"\ >* : C H ui0- 0'*0i ,n EXPLANATION ^t,'^''" \*" A 0284 SURFACE-WATER STATION AND NUMBER W 0205 QUALITY-OF-WATER STATION AND NUMBER * * "> Y7n?nnRn QUALITY-OF-WATER PARTIAL RECORD 1 V IMUUDU STATION AND NUMBER I _A 0280 DAILY SEDIMENT STATION AND NUMBER j 0 204 WELL AND WELL NUMBER 1026140 LAKE-ELEVATION STATION AND NUMBER 3 4 f 6 KILOMETERS Figure 15.--Rio Grande de Arecibo basin. 62 RIO GRANDE DE ARECIBO BASIN 50020100 LAGO GARZAS NEAR ADJUNTAS, PR LOCATION.--Lat 16°0e'20", long 66°44'29", Hydrologic Unit 21010002, in power gate tower of Garzas Dam on Rio Vacas, 1.7 mi (2.7 km) upstream from Rio Garzas, and 2.2 mi (3.5 km) southwest of Ad juntas. DRAINAGE AREA.--15.6 mi 9 (40.4 km3 ). ELEVATION RECORDS PERIOD OP RECORD.--January 1986 to May 1969, 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, 1966 at datum 2,376.60 ft (724.449 m), Hay 25 to July 13, 1968 at datum 2,336.06 ft (712.647 m), July 14, 1968 to May 25, 1969 at datum 2,337.62 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 ueed for irrigation and power production. Operated by P.R. Electric Power Authorithy. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,417.66 ft (736.903 m), May 27, 1993; minimum elevation, 2,364.79 ft (720.766 m), Aug. 23, 1966. EXTREMES OBSERVED FOR CURENT YEAR.--Maximum elevation 2,414.43 ft (735.916 m), Sept. 29; minimum elevation, 2,374.66 ft (723.657 m), Feb. 20. Capacity table (based on data from Puerto Rico Electric Power Authorithy) Elevation, in feet 2,364 2,362 2,394 Contents, in acre-feet 660 1,500 2,250 Elevation, in feet 2.415 2.416 Contents, in acre-feet 4,062 4,411 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES OCT NOV FEB APR MAY 1 2 3 4 5 6 7 6 9 10 11 12 13 14 15 16 17 16 19 20 21 22 23 24 25 26 27 26 29 30 31 A A A A A 2366.44 2364.60 2364.15 2383.65 A A A A A A A A A A A 2390.94 2391.64 2392.00 2392.56 2393.22 2393.60 2393.62 2393.94 2394.02 2394.26 2394.36 2394.38 2394.54 2395.79 2395.93 2396.03 2396.11 2396.43 2396.49 2396.65 2396.73 2396.76 2396.77 2396.77 2396.75 2396.73 2396.45 2396.43 2396.47 2396.45 2396.44 2396.40 2396.36 2396.30 2396.24 2396.16 2396.09 2396.50 2396.50 2396.46 2396.44 2396.55 2396.56 2396.64 2396.70 2396.70 2396.66 2396.62 2396.56 2396.50 2396.44 2396.36 2396.26 2396.16 2396.06 2395.96 2395.69 2395.62 2395.72 2395.62 2395.75 2395.70 .2395.64 2395.72 2395.64 2395.56 2395.50 2395.68 2395.64 2395.56 2395.50 2395.36 2395.26 2395.16 2395.04 2394.92 2394.56 2394.36 2394.10 2393.64 2393.61 2393.36 2393.16 2393.18 2393.04 2392.96 2392.96 2392.76 2392.52 2392.26 2392.04 2391.74 2391.44 2391.16 2390.66 2390.55 2390.27 2390.11 2369.60 2369.49 2369.16 2366.84 2368.50 2366.14 2367.65 2367.64 2367.64 2367.76 2367.76 2367.76 2367.43 2386.90 2366.19 2365.62 2365.16 2384.78 2364.46 2364.50 2383.52 2363.04 2361.94 2360.02 A A A A A A A A A ___ ___ —— A A A A A 2369.62 A A A A A A A A A A A A A A A A A A A A A A A A A MAX MIN —— 2396.77 2396.70 —— 2394.36 2395.36 2395.28 2366.50 A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A •-- .__ .__ A A A A A A A A A 2365.32 2365.35 2385.33 2385.27 2365.31 2365.63 2365.97 2385.97 2385.91 2365.62 2385.64 2365.72 2365.64 2365.52 2365.30 2365.16 2364.96 2364.96 2384.82 2364.66 2385.60 2366.16 ___ 2366.60 2366.92 2366.94 2366.60 2367.51 2367.53 2367.51 2387.49 2386.61 2388.63 2368.87 2366.67 2388.87 2386.63 2366.69 2386.91 2368.65 2366.67 2366.53 2366.37 2366.16 2386.03 2367.96 2367.76 2367.70 2367.58 2391.56 2391.70 2391.70 2391.62 --- 2391.70 2366.80 2391.56 2391.34 2391.26 2391.16 2391.10 2391.06 2390.96 2390.66 2390.62 2390.76 2390.73 2390.73 2390.67 2390.61 2390.71 2390.63 2390.77 2390.71 2390.65 2390.69 2390.93 2390.95 2390.93 2390.91 2390.61 2390.71 2390.57 2392.19 2392.05 2392.17 2392.17 2392.19 2390.57 2392.10 2391.96 2391.66 2391.76 2394.54 2394.76 2394.62 2394.72 2394.74 2394.74 2394.70 2394.63 2394.57 2394.51 2394.47 2395.37 2395.47 2396.55 2396.04 2398.42 2396.60 2399.96 2400.70 2401.20 2401.46 2401.63 2401.79 2401.97 2402.11 2402.23 2402.33 2402.33 2391.76 2402.41 2402.53 2402.62 2402.66 2403.02 2403.66 2404.54 2404.76 2404.96 2405.53 2405.53 2405.63 2405.73 2405.61 2406.67 A A A 2412.12 2412.44 2412.61 2413.40 2413.69 2414.16 2414.33 2414.37 2414.42 2414.41 2414.42 2414.41 --- ___ ___ A No gage-height record RIO GRANDE DE ARECIBO BASIN 63 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR WATER-QUALITY RECORDS LOCATION.—Lat 18°10'54", long 66°44'12", at Highway 135 bridge, 1.0 mi (1.6 km) upstream from Lago Ad juntas, and 1.5 mi (2.4 km) northwest of Adjuntas plaza. DRAINAGE AREA.--12.7 mi 2 (32.9 km 2 ) this does not include 6.0 mi 5 (15.6 km1 ) above Lago Garzas. PERIOD OP RECORD.--Water years 1969-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE NOV 1994 02. .. DEC 20. .. PEB 1995 14. .. MAY 08. .. JUN 21. .. SEP 12. .. DATE NOV 1994 02... DEC 20... PEB 1995 14. .. MAY 08. . . JUN 21... SEP 12. .. TIME 1215 0915 0905 1315 0835 0955 HARD- NESS TOTAL (MG/L AS CACO3) 120 -- -- 110 — 100 SILICA, DATE NOV 1994 02. .. DEC 20... PEB 1995 14. .. MAY 08... JUN 21... SEP 12... K = non-ideal DIS- SOLVED (MG/L AS SI02) 30 -- -- 25 -- 28 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 16 10 7.1 39 17 51 CALCIUM DIS- SOLVED (MG/L AS CA) 33 -- -- 29 -- 26 SOLIDS, SUM OP CONSTI- TUENTS, DIS- SOLVED (MG/L) 196 -- -- 180 -- 180 SPE- CIFIC CON- DUCT- ANCE (US/CM) 316 341 394 303 328 278 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 10 _- -- 8.9 — 8.7 SOLIDS, DIS- SOLVED (TONS PER DAY) 8.30 -- -- 18.8 — 24.9 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.4 7.7 7.6 7.3 7.7 6.4 SODIUM, DIS- SOLVED (MG/L AS NA) 19 __ -_ 20 -_ 19 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 6 2 4 3 4 5 TEMPER- ATURE WATER (DEG C) 24.0 20.0 19.5 24.5 23.0 23.5 SODIUM AD- SORP- TION RATIO 0.7 — __ 0.8 __ 0.8 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.30 <0.20 <0.20 <0.20 0.35 0.42 TUR- BID- ITY (NTU) 1.5 2.1 0.80 3.2 0.90 6.7 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 1.8 __ __ 2.3 __ 3.1 PHOS- PHORUS TOTAL (MG/L AS P) 0.060 0.080 0.130 0.060 0.120 0.090 OXYGEN, DIS- SOLVED (MG/L) 8.1 8.3 7.9 7.0 7.7 5.8 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CACO3 110 120 120 94 120 98 ARSENIC TOTAL (UG/L AS AS) <1 -- -- <1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 100 94 90 89 94 71 SULFIDE TOTAL (MG/L AS S) <0.5 __ __ 0.6 -- — — BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 11 <10 11 <10 <10 12 SULFATE DIS- SOLVED (MG/L AS 804) 11 __ -- 9.6 -- 10 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 30 -- -- 20 -- — COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 2800 210 K120 4300 200 3500 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 25 -- -- 29 -- 26 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 530 260 490 4000 200 2700 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 __ -- <0.10 — <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- — <1 — — 64 Rro GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NR ADJUNTAS, PR--CONTINDED WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE NOV 1994 02. .. DEC 20. . . FEB 1995 14. .. MAY oe... JUN 21. . . SEP 12. .. COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (DG/L MANGA- NESE, TOTAL RECOV- ERABLE (DG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (DG/L SILVER, TOTAL RECOV- ERABLE (DG/L ZINC, TOTAL RECOV- ERABLE (DG/L METHY- LENE BLUE CYANIDE ACTIVE TOTAL PHENOLS SUB- (MG/L TOTAL STANCE AS CD) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (DG/L) 200 260 90 70 0.10 <0.10 <0.010 <0.010 (MG/L) 0.02 <0.02 RIO GRANDE DE ARECZBO BASIN 50025000 RIO GRANDE DE ARECIBO NEAR UTUADO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°18'11", long 66°41'59 M , at bridge near Highway 10 at km 56.4, 0.5 mi (0.8 km) downstream from Rio de Caguana, and 2.5 mi (4.0 km) north of Utuado plaza. DRAINAGE AREA.--66.0 mi 2 (170.9 km2 ) this excludes 6.0 mi 2 (15.5 km2 ) upstream from Lago Garzas to Rio Guayanes in the Rio Tallaboa basin. PERIOD OP RECORD.--Water years 1959-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 24. .. DEC 20. .. FEB 1995 13. .. APR 28. . . JUN 20. .. AUG 30. . . DATE OCT 1994 24. .. DEC 20. .. FEB 1995 13. .. APR 28. .. JUN 20. . . AUG 30. . . TIME 1420 0735 1050 1225 1050 0840 HARD- NESS TOTAL (MG/L AS CAC03) 93 -- — 130 -- 120 SILICA, DATE OCT 1994 24. .. DEC 20. . . FEB 1995 13. .. APR 28. .. JtJN 20. .. AUG 30. .. R = non-ideal DIS- SOLVED (MG/L AS SI02) 24 — -- 27 -- 30 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 112 45 21 24 58 57 CALCIUM DIS- SOLVED (MG/L AS CA) 26 -- -- 35 -- 32 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 150 -- -- 201 -- 193 SPE- CIFIC CON- DUCT- ANCE (US/CM) 235 254 324 329 300 290 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 6.9 -- -- 9.3 -- 9.8 SOLIDS, DIS- SOLVED (TONS PER DAY) 45.4 -- — 13.1 -- 29.9 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.4 7.5 7.7 7.6 8.1 7.2 SODIUM, DIS- SOLVED (MG/L AS NA) 12 -- -- 18 -- 15 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 116 130 5 5 30 95 TEMPER- ATURE WATER (DEG C) 27.0 22.0 21.0 28.0 25.0 25.0 SODIUM AD- SORP- TION RATIO 0.5 -- — 0.7 — 0.6 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.30 0.50 <0.20 0.80 0.36 0.24 TUR- BID- ITY (NTU) 96 110 1.0 6.4 12 52 POTAS- SIUM, DIS- SOLVED (MG/L AS R) 2.2 -- -- 2.6 -- 2.1 PHOS- PHORUS TOTAL (MG/L AS P) 0.130 0.180 0.130 0.170 0.140 0.040 OXYGEN, DIS- SOLVED (MG/L) 7.7 7.4 9.0 8.0 7.7 5.6 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CACO3 80 85 110 100 100 110 ARSENIC TOTAL (UG/L AS AS) <1 -- — <1 -- — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 96 84 102 104 94 67 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 -- — — BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 14 16 <10 13 <10 12 SULPATE DIS- SOLVED (MG/L AS SO4) 19 — -- 29 — 21 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 40 — -- 30 — — COLI- FORM, FECAL, 0.45 UM-MF (COLS . / 100 ML) 4500 23000 R1200 2400 K9700 K17000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 12 -- -- 20 -- 17 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 3000 51000 290 540 R1600 2500 PLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 -- -- 0.10 -- 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 2 -- — <1 — -- 66 RIO GRANDE DE ARECIBO BASIN 50025000 RIO GRANDE DE ARECIBO NEAR UTUADO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 24. .. DEC 20. .. PEB 1995 13. .. APR 28... JUN 20. .. AUG 30. .. COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L METHY- LENE BLUE CYANIDE ACTIVE TOTAL PHENOLS SUB- (MG/L TOTAL STANCE AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) 10 2800 270 230 50 <0.10 <0.10 <1 20 <0.010 <0.010 (MG/L) <0.02 0.04 67 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTS AT COABEY NEAR JAYUYA, PR LOCATION. --Lat 18°12'48 n , 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 Gripifias. DRAINAGE AREA.--9.25 mi 1 (23.96 km1 )- WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1989 to current year. GAGE.--water-stage recorder. Elevation oC gage is 1,706 ft (520 m), from topographic map. REMARKS.--Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY NOV DEC JAN MAR APR MAY JUN JUL AUG SEP 1 22 13 2 9.1 56 3 7.2 40 4 6.3 19 5 5.6 16 6 7.3 15 7 7.0 14 8 139 13 9 35 41 10 18 27 11 12 20 12 15 15 13 9.3 14 14 122 12 15 46 12 16 18 11 17 17 10 18 42 10 19 21 9.6 20 14 9.5 21 12 9.0 22 21 8.8 23 114 8.3 24 49 8.1 25 66 9.2 26 30 10 27 28 10 28 21 9.5 29 17 8.8 30 15 8.5 31 14 TOTAL 959.8 467.3 MEAN 31.0 15.6 MAX 139 56 MIN 5.6 8.1 AC-FT 1900 927 CFSM 3.35 1.68 IN. 3.86 1.88 STATISTICS OF MONTHLY MEAN MEAN 37.2 22.6 MAX 70.5 40.0 (WY) 1991 1991 MIN 11.6 10.0 (WY) 1992 1994 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 7.9 7.7 8.3 9.0 7.5 7.2 7.0 6.8 6.6 5.8 5.8 5.7 5.6 5.5 5.2 5.1 5.1 5.1 5.1 4.9 4.7 4.7 4.9 5.1 6.0 6.1 5.3 5.4 5.4 5.4 5.2 185.1 5.97 9.0 4.7 367 .65 .74 DATA 12.1 22.7 1993 5.97 1995 FOR 5.1 5.0 .7 .7 .7 .7 .5 .1 .1 .1 .3 .0 .0 .0 3.9 3.8 3.7 3.6 .0 .3 .1 .0 .1 .1 .0 3.8 3.8 3.8 3.8 3.6 3.6 128.0 4.13 5.1 3.6 254 .45 .51 FOR WATER 16.4 48.1 1992 4.13 1995 3.6 3.6 3.5 3.5 3.3 3.3 3.7 6.3 4.4 5.0 3.9 3.5 3.4 3.1 3.1 3.1 3.2 3.4 3.8 3.9 43 17 6.5 5.2 26 122 60 26 ___ — - 380.3 13.6 122 3.1 754 1.47 1.53 YEARS 1989 11.3 16.0 1993 4.67 1994 71 39 18 17 13 9.6 8.1 7.5 6.8 9.6 16 21 20 21 21 17 13 11 9.7 8.8 8.2 7.7 7.5 6.8 6.5 6.2 6.3 6.2 5.7 5.6 5.5 430.3 13.9 71 5.5 853 1.50 1.73 - 1995 10.4 13.9 1995 4.79 1994 1994 CALENDAR YEAR 4301. 11. 607 2. 2. 8530 1. 17. 19 4. 3. 8 8 Jun 2 3 Jul 27 5 Jul 23 27 30 9 1 5.3 5.1 5.1 5.0 4.9 4.7 4.8 5.1 5.0 5.4 5.0 22 8.9 6.7 5.8 11 13 11 5.6 4.7 4.3 4.8 4.2 4.1 3.9 3.7 3.6 3.5 3.5 3.7 —— 183.4 6.11 22 3.5 364 .66 .74 4.1 3.4 3.2 11 50 60 363 413 709 287 90 45 28 19 43 30 18 15 12 25 19 13 11 10 24 60 156 84 204 156 90 3055.7 98.6 709 3.2 6060 10.7 12.29 63 53 51 48 39 29 26 24 18 17 19 21 15 12 12 11 9.3 8.3 7.6 7.1 6.9 6.5 6.1 5.8 5.5 7.4 120 67 21 15 --- 751.5 25.0 120 5.5 1490 2.71 3.02 12 10 9.2 9.5 9.2 13 11 8.2 7.5 7.0 9.2 9.6 13 14 82 39 16 11 9.1 7.9 8.4 11 8.5 7.4 6.6 6.1 6.1 6.5 8.4 180 64 620.4 20.0 180 6.1 1230 2.16 2.50 19 14 12 9.7 8.4 33 26 13 10 8.6 7.9 7.0 8.5 8.6 7.5 61 25 361 249 154 102 61 47 43 37 29 24 42 43 26 22 1519.2 49.0 361 7.0 3010 5.30 6.11 19 17 16 15 59 682 498 182 70 44 77 52 36 25 137 1800 738 272 108 352 162 78 286 148 71 52 240 97 55 41 6429 214 1800 15 12750 23.2 25.85 , BY WATER YEAR (WY) 19.1 46.4 1993 5.95 1994 FOR 1995 15110 41 1800 3 3 3840 12 3 29970 4 60 77 9 4 41.2 98.6 1995 5.35 1990 WATER YEAR .0 .4 Sep 16 .1 Feb 14 .3 Feb 12 Oct 8 .33 Oct 8 .0 Feb 17 .48 .77 .7 .0 23.2 35.4 1994 10.1 1991 13.0 20.0 1995 2.83 1994 WATER 23 41 10 1800 2 2 5900 13 2 17070 2 34 43 11 4 21.1 49.0 1995 9.82 1994 YEARS 1989 .6 .4 .9 Sep .3 Jul .5 Jul Jun .92 Jun .1 Jul .55 .61 .2 54.9 214 1995 10.8 1994 - 1995 1995 1994 16 1995 27 1994 23 1994 2 1994 2 1994 26 1994 68 LOCATION.--Lat 18°13' Caonillas, 3.3 mi DRAINAGE AREA.--40.4 PERIOD OF RECORD.--We RIO GRANDE DE ARECIBO BASIN 50026050 RIO CAONILLAS ABOVE LAGO CAONILLAS NEAR JAYUYA, PR WATER-QUALITY RECORDS 26", long 66 0 38'22", 300 ft (91 m) off Highway 531, 700 ft (213 m) upstream from (5.3 km) northwest of Jayuya plaza. mi' (104.6 km»)- ,ter years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 Lago DATE NOV 1994 02... DEC 20. .. FBB 1995 14. .. HAY 09. .. JUN 21. .. SEP 11. .. DATE NOV 1994 02. .. DEC 20... FBB 1995 14. .. HAY 09. .. JUN 21. .. SEP 11. .. TIME 1445 1110 1130 0910 1115 0925 HARD- NESS TOTAL (HG/L AS CAC03) 82 -- -- 63 — 69 SILICA, DATE NOV 1994 02... DEC 20. .. FEB 1995 14. .. HAY 09. .. JUN 21. .. SEP 11... K B non-ideal E = Estimated DIS- SOLVED (MG/L AS SI02) 23 -- -- 19 — 24 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 33 16 9.1 E250 37 91 CALCIUM DIS- SOLVED (MG/L AS CA) 22 -_ -- 16 -- 19 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 133 -- -- 106 __ 119 SPE- CIFIC CON- DUCT- ANCE (US /CM) 206 244 250 173 235 180 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 6.5 — — 5.6 -- 5.3 SOLIDS, DIS- SOLVED (TONS PER DAY) 11.6 __ — __ __ 29.5 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.4 7.9 7.8 7.3 7.8 6.6 SODIUM, DIS- SOLVED (MG/L AS NA) 12 __ __ 9.3 -- 10 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 6 3 5 38 5 <1 TEMPER- ATURE WATER (DBG C) 26.0 23.0 23.0 21.0 26.0 24.0 SODIUM AD- SORP- TION RATIO 0.6 _ __ 0.5 __ 0.5 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 <0.20 <0.20 0.30 0.24 0.29 TUR- BID- ITY (NTU) 1.6 2.6 0.60 41 1.5 4.0 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 1.7 __ __ 2.2 -- 2.4 PHOS- PHORUS TOTAL (MG/L AS P) 0.090 0.080 0.080 0.070 0.040 0.050 OXYGEN, DIS- SOLVED (MG/L) 8.2 8.5 8.9 8.1 7.8 8.2 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 69 82 82 43 82 58 ARSENIC TOTAL (UG/L AS AS) <1 __ __ <1 __ -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 102 100 106 93 99 100 SULFIDE TOTAL (MG/L AS S) <0.5 __ __ <0.5 __ -• BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 __ __ <100 __ -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 10 <10 <10 16 <10 12 SULFATE DIS- SOLVED (MG/L AS S04) 15 __ -_ 16 -- 13 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 20 -- __ 30 __ -- COLI- FORM, FECAL, 0.45 DM-MF (COLS./ 100 ML) K100 320 K140 6400 K140 K910 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 11 __ __ 12 -- 11 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -_ __ <1 __ -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K160 K80 K18 20000 K10 440 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 __ — <0.10 -- <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- — 1 -- -- RIO GRANDE DE ARECIBO BASIN 50026050 RIO CAONILLAS ABOVE LAGO CAONILLAS NEAR JAYUYA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 ZINC, TOTAL RECOV- CYANIDE ERABLE TOTAL PHENOLS (UG/L (MG/L TOTAL AS CU) AS FE) AS PB) AS MN) AS HG) AS SB) AS AG) AS ZN) AS CN) (UG/L) 69 DATE COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L NOV 1994 02. .. DEC 20... FEB 1995 14... MAY 09. .. JUN 21. .. SEP 11. .. 180 10 2000 30 <0.10 120 <0.10 <0.010 10 <0.010 METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) <0.02 <0.02 70 RIO GRANDE DE ARECIBO BASIN 50026140 LAGO CAONILLAS AT DAMSITE NEAR OTDADO, PR LOCATION.--Lat 18°16'43", long 66°39'24", Hydrologic Unit 21010001, at Lago CaonillaB Dam on Rio CaonillaB, 2.9 mi (4.7 km) northeast of Plaza de Utuado, 0.3 mi (0.6 km) west from Iglesia Santa Maria del Monte Carmelo, and 1.8 mi (3.0 km) northwest from Hacienda Carbonell. DRAINAGE AREA.--48.4 mi' (125.4 km1 ). ELEVATION RECORDS PERIOD OF RECORD.—March 1991 to current year. Prior to October 1994, published as Lago CaonillaB at CaonillaB. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago CaonillaB 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). Nonoverflow sections on each abutment have a total length of €03 ft (184 m). The dam is the main unit of CaonillaB Hydroelectric Project, and provides 49,000 acre-feet (60 hmj ) of usable storage for power generation at CaonillaB 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. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 825.39 ft (251.58 m), June 7, 1993; minimun elevation, 752.23 ft (229.27 m), Oct. 2, 1994. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 814.22 ft (248.17 m), Jun. 12; minimum elevation, 752.23 ft (229.27 m), Oct. 2. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet 705 750 Contents, in acre-feet 0 8,421 Elevation, in feet 800 830 Contents, in acre-feet 27,982 46,161 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES DAY OCT NOV JAN FEB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX MXN 754.16 753.51 753.53 753.52 753.76 754.18 754.44 756.02 757.26 757.85 758.39 759.56 760.11 760.89 761.48 761.70 761.74 762.31 762.62 763.03 763.57 763.92 764.72 765.30 765.91 766.24 766.57 766.80 766.96 767.12 767.31 767.31 753.51 767.46 767.63 813.90 768.67 768.79 768.86 769.03 769.11 769.33 769.73 769.86 769.97 770.06 770.14 770.20 769.25 768.93 768.99 769.11 769.17 769.20 768.46 768.45 768.46 768.59 768.66 768.70 768.17 768.32 768.35 --- 813.90 767.46 768.45 768.59 768.61 768.62 768.72 768.73 768.74 768.82 768.79 768.78 768.76 768.80 768.78 768.75 768.72 768.83 769.12 769.16 769.17 769.15 768.56 768.53 768.50 768.43 768.41 768.40 768.37 768.34 768.30 768.26 768.21 769.17 768.21 768.16 768.12 768.08 768.03 768.02 767.98 767.93 767.89 767.82 767.78 767.72 767.69 767.70 767.65 767.59 767.56 767.46 767.42 767.34 767.23 767.18 767.13 767.08 A A A A A A A A ___ A A A A A A A A A A A A A A A A A A A A A A A A A A A A ... __. MAR A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A APR A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A J0L AUG SEP A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A .__ 813 813 814 814 813 812 812 812 812 812 812 811 810 810 809 808 808 808 808 808 808 807 806 A A A A A A A .83 .98 .04 .18 .36 .55 .60 .06 .04 .10 .14 .19 .92 .61 .82 .82 .85 .85 .50 .07 .40 .50 .84 --- ___ 806. 806. 805. 805. 804. 804. 803. 803. 803. 804. 803. 802. 802. 800. 800. 799. 798. 797. 795. 794. 793. 792. 792. 790. 790. 789. 788. 787. 786. 786. 786. 806. 786. 17 13 10 03 36 17 81 59 60 43 42 90 05 97 48 95 48 05 71 30 01 80 16 82 66 20 46 41 52 94 51 17 51 786 786 785 785 785 785 784 784 784 784 784 784 784 784 785 785 785 786 787 788 787 788 788 788 788 788 788 788 788 788 788 788 784 .60 .45 .46 .51 .25 .36 .94 .81 .85 .87 .72 .73 .81 .95 .01 .23 .39 .24 .52 .12 .96 .23 .44 .61 .74 .81 .51 .52 .67 .79 .79 .81 .72 788. 788. 788. 788. 788. 790. 792. 792. 792. 793. 793. 794. 794. 795. 794. 805. 807. 808. 809. 810. 810. 809. 810. 810. 810. 810. 811. 812. 812. 812. - 812. 788. 88 58 77 68 94 64 04 42 97 34 97 47 80 08 30 33 55 80 49 18 15 68 24 98 79 58 56 26 20 09 -- 26 58 A No gage-height record 71 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DB 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 ad (1.1 km) downstream from Lago Dos Bocas and 6.6 mi (10.6 km) west of Florida plaza. DRAINAGE ARBA.--169 mi 1 (436 km 1 ) does not include 6.0 mi 1 (15.6 km 1 ) above Lago Garzas. PERIOD OF RECORD.--Water years 1970-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 31. .. DEC 21. .. FEB 1995 13... APR 21. .. JUN 20. .. ADG 30. .. DATE OCT 1994 31. .. DEC 21. .. FEB 1995 13. .. APR 21... JTJN 20. .. ADG 30. .. DATE OCT 1994 31. .. DEC 21. .. FEB 1995 13. .. APR 21. .. JTJN 20. .. ADG 30. .. TIME 1215 0800 0925 0930 0850 1025 HARD- NESS TOTAL (MG/L AS CACO3) 97 -- -- 97 — 97 SILICA, DIS- SOLVED (MG/L AS SIO2) 22 -- -- 20 -- 22 DIS- CHARGE, INST. CUBIC FEET PER SECOND E1000 21 18 21 E600 31 CALCIUM DIS- SOLVED (MG/L AS CA) 27 -- -- 27 __ 27 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 156 -- -- 146 -- 145 SPE- CIFIC CON- DUCT- ANCE (US/CM) 254 245 255 245 220 250 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 7.3 -_ -- 7.1 — 7.1 SOLIDS, DIS- SOLVED (TONS PER DAY) — — -- 8.46 — 12.1 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.1 7.6 7.6 7.4 7.3 6.7 SODIUM, DIS- SOLVED (MG/L AS NA) 13 __ __ 11 __ 11 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MO/L) 7 4 8 <1 18 1 TEMPER- ATURE WATER (DEG C) 27.0 25.0 24.0 26.0 25.0 28.5 SODIUM AD- SORP- TION RATIO 0.6 __ -- 0.5 __ 0.5 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.30 <0.20 <0.20 0.20 0.38 0.46 TUR- BID- ITY (NTU) 5.4 3.5 1.2 0.30 13 2.0 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 3.1 __ -- 2.6 __ 2.4 PHOS- PHORUS TOTAL (MG/L AS P) 0.020 0.010 0.020 <0.010 0.020 0.040 OXYGEN, DIS- SOLVED (MG/L) 4.4 4.4 5.2 5.4 4.0 4.3 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 87 92 95 88 78 82 ARSENIC TOTAL (UG/L AS AS) <1 -- -- <1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 54 52 61 67 48 55 SULFIDE TOTAL (MG/L AS S) <0.5 __ -- <0.5 __ — — BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MO/L) 18 12 <10 <10 <10 <10 SULFATE DIS- SOLVED (MG/L AS S04) 17 __ -- 13 — 13 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 10 -- -- 30 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 2100 300 K18 K10 520 K60 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 14 _- -- 13 __ 13 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 260 300 K10 340 400 K70 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 — -- <0.10 __ 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 -- -- E = Estimated K = non-ideal count 72 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 31. .. DEC 21... PEB 1995 13. .. APR 21... JUN 20. .. AUG 30. . . COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 — -- <10 -- — IRON, TOTAL RECOV- ERABLE (UG/L AS FE) 170 -- __ 40 -_ -- LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) 4 — __ 1 __ — MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 120 __ __ 40 __ -- MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) 0.10 — __ <0.10 — -- SELE- NIUM, TOTAL (UG/L AS SB) <1 -- __ <1 __ -- SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <1 — __ <1 __ — ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) <10 -- __ <10 __ -- CYANIDE TOTAL PHENOLS (MG/L TOTAL AS CN) (UG/L) <0.010 3 __ — <0.010 <1 — — METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) <0.02 -- -- <0.02 -- — 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 Rio Tanama, 3.6 mi (5.8 km) south of Arecibo and 4.9 mi (7.9 km) above mouth, and 6.2 mi (9.97 km) downstream from Lago Dos Bocas. DRAINAGE AREA.—200 mi 2 (520 km2 ), approximately, of which an undetermined amount does not contribute directly to surface runoff. WATER-DISCHARGE RECORDS PERIOD OP RECORD.--April 1982 to current year. GAGE.—Water-stage recorder. Elevation of gage is 30 ft (9 m), from topographic map. REMARKS.—Records fair. 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 73 DAY NOV APR HAY JUN JUL 1 57 191 2 54 118 3 213 363 4 98 338 5 75 176 6 99 90 7 82 52 8 46 50 9 125 65 10 291 273 11 63 72 12 81 91 13 471 60 14 227 43 15 220 123 16 165 377 17 341 78 18 83 149 19 365 43 20 463 43 21 189 62 22 158 170 23 137 234 24 175 62 25 251 39 26 189 67 27 78 101 28 128 91 29 55 45 30 53 35 31 258 — - TOTAL 5290 3701 MEAN 171 123 MAX 471 377 MIN 46 35 AC-FT 10490 7340 CFSM .85 .62 IN. .98 .69 STATISTICS OF MONTHLY MEAN MEAN 629 550 MAX 1984 1413 (WY) 1986 1986 MIN 171 123 (WY) 1995 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 64 34 37 31 31 71 111 38 36 30 29 119 123 89 76 62 49 48 108 50 132 136 129 75 55 87 91 81 56 113 52 2243 72.4 136 29 4450 .36 .42 DATA 287 570 1988 72.4 1995 FOR 73 51 52 78 84 85 54 111 69 117 90 65 108 54 45 43 41 62 221 101 63 103 51 40 60 75 50 44 75 61 364 2590 83.5 364 40 5140 .42 .48 FOR WATER 240 437 1988 83.5 1995 301 102 109 40 39 36 36 36 36 36 36 35 33 33 34 33 33 33 34 32 35 36 38 117 58 59 154 111 ___ --- 1715 61.2 301 32 3400 .31 .32 YEARS 1982 219 428 1988 61.2 1995 65 639 669 266 276 114 115 73 69 87 112 94 80 287 147 74 165 86 112 307 129 67 137 329 206 68 150 102 82 203 104 5414 175 669 65 10740 .87 1.01 - 1995 214 351 1985 91.2 1994 1994 CALENDAR YEAR 38813 106 755 16 22 76990 7. 261 62 28 May 23 Apr 14 Mar 30 53 22 71 91 56 53 52 52 53 52 51 65 56 230 86 52 56 52 46 106 87 46 42 41 40 39 47 122 49 86 51 42 —— 1972 65.7 230 39 3910 .33 .37 44 41 41 48 310 156 107 50 96 757 542 289 157 330 484 890 873 360 452 741 296 463 276 696 408 155 179 406 906 1100 878 12531 404 1100 41 24860 2.02 2.33 403 383 311 168 538 580 325 550 319 360 675 596 555 359 593 564 210 95 201 298 161 472 207 98 158 178 334 218 490 350 10749 358 675 95 21320 1.79 2.00 151 205 78 160 443 201 148 85 182 312 408 286 468 596 325 343 650 665 551 216 50 43 151 372 200 348 374 260 436 127 339 9173 296 665 43 18190 1.48 1.71 110 122 282 228 43 116 190 85 59 60 170 52 29 27 25 22 22 112 219 101 334 55 89 421 281 166 57 166 97 196 125 4061 131 421 22 8050 .65 .76 143 36 102 18 96 126 650 555 158 145 367 100 236 220 208 3620 1920 859 705 732 751 571 470 360 224 470 435 825 581 527 --- 16210 540 3620 18 32150 2.70 3.02 , BY WATER YEAR (WY) 359 617 1986 65.7 1995 FOR 1995 75649 207 3620 18 33 6450 12 150000 1 14 486 111 39 615 2000 1986 178 1994 WATER YEAR Sep 16 Sep 4 Feb 14 Sep 16 .34 Sep 16 .04 .07 368 683 1987 69.3 1994 263 374 1987 62.7 1994 WATER 371 729 132 14800 16 22 45800 18 269000 1 25 766 241 54 254 474 1988 82.8 1994 YEARS 1982 May Apr Mar May .22 May .86 .22 461 1080 1984 99.9 1994 - 1995 1986 1994 18 1985 14 1994 30 1994 18 1985 18 1985 74 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR 0TUADO, PR LOCATION.--Lat 180 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 mi 1 (47.7 km1 ). 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 (286.000 m) above mean sea level. Datum of gage was lowered 3.00 ft (0.914 m) on Oct. 1978. Prior to Nov. 17, 1966, non-recording gage and Nov. 17, 1966 to Sept. 30, 1978 recording gage, both at present site. REMARKS.--Records fair except those for estimated daily discharges, which are poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES NOV APR AUG SEP 1 23 32 2 23 25 3 19 24 4 17 24 5 17 22 6 32 21 7 32 21 8 69 21 9 40 25 10 80 26 11 68 22 12 119 20 13 64 20 14 107 19 15 44 19 16 34 19 17 36 24 18 55 22 19 36 47 20 35 39 21 37 22 22 36 20 23 31 19 24 28 19 25 42 63 26 31 32 27 30 23 28 32 21 29 26 22 30 25 21 31 25 —— TOTAL 1293 754 MEAN 41.7 25.1 MAX 119 63 MIN 17 19 AC-FT 2560 1500 CFSM 2.27 1.37 IN. 2.61 1.52 STATISTICS OF MONTHLY MEAN MEAN 78.7 67.6 MAX 195 159 (VTY) 1990 1969 MIN 25.4 25.1 (WY) 1963 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS e Estimated 23 37 24 21 21 20 19 19 19 18 19 19 19 19 18 27 93 49 39 34 24 22 21 21 23 23 22 22 21 20 20 796 25.7 93 18 1580 1.40 1.61 DATA 42.4 121 1966 21.5 1965 FOR 20 19 19 18 17 18 17 16 17 16 15 15 17 18 24 25 16 16 17 17 19 22 18 17 17 40 26 22 20 18 18 598 19.3 40 15 1190 1.05 1.21 FOR WATER 28.8 50.1 1966 18.0 1974 18 18 17 17 16 16 16 17 13 19 14 14 13 13 13 13 13 13 13 13 14 83 32 24 101 65 53 46 ___ —— 717 25.6 101 13 1420 1.39 1.45 YEARS 1960 24.9 40.5 1961 13.2 1965 55 35 40 39 38 e29 e44 e62 e33 e49 e35 e27 e35 e30 e27 e25 e24 e23 e22 e21 e20 e!9 el9 el9 el9 el8 e!8 e!7 e!8 e!7 e!7 894 28.8 62 17 1770 1.57 1.81 - 1995 24.6 71.2 1972 11.0 1984 1994 CALENDAR YEAR 7267. 19. 119 5. 6. 14420 1. 14. 35 16 10 6 9 Oct 12 4 Aug 4 4 Jul 29 08 69 e!7 e!6 e!6 e!6 e!5 e!5 el6 e29 e36 e22 e25 e20 el9 el8 e!7 el9 e23 el8 el5 e!7 el5 el5 el4 el4 el6 el6 el 6 el6 el5 el6 --- 542 18.1 36 14 1080 .98 1.10 e!5 e!4 e!9 e60 e84 e29 e42 elOS ellO 90 94 64 71 73 204 121 69 68 76 75 58 47 44 41 47 42 47 39 41 41 64 2014 65.0 204 14 3990 3.53 4.07 55 49 90 55 341 90 63 69 85 75 57 52 48 46 50 67 52 46 44 48 42 40 40 39 37 37 38 39 35 34 --- 1863 62.1 341 34 3700 3.37 3.77 33 32 32 33 42 46 38 32 31 29 42 32 40 38 29 27 26 25 26 25 29 26 24 26 28 33 33 32 32 32 33 986 31.8 46 24 1960 1.73 1.99 31 53 39 31 29 31 31 29 31 27 26 25 26 29 24 39 31 36 48 33 29 28 29 27 27 26 25 25 24 24 36 949 30.6 53 24 1880 1.66 1.92 25 24 55 33 49 133 110 53 61 45 87 50 e40 e36 61 412 114 89 78 72 71 64 103 75 63 67 96 98 71 64 --- 2399 80.0 412 24 4760 4.35 4.65 , BY WATER YEAR (WY) 36.5 142 1969 9.70 1984 FOR 1995 13805 37. 412 13 13 4120 13. 12 27380 2. 27. 71 28 16 58.2 193 1963 12.4 1977 WATER YEAR e Sep 16 Feb 9 Feb 13 Jun 5 32 Jun 5 Feb 19 06 91 42.7 116 1979 15.6 1994 36.5 65.7 1981 9.18 1994 HATER 46 71 20 2170 5 6 12200 17 5 33830 2 34 82 32 16 45.7 110 1979 15.9 1994 YEARS 1960 - .7 .1 .7 May 17 . 4 Aug 4 .4 Jul 29 May 18 .45 May 18 .4 Jul 29 .54 .48 73.2 177 1961 25.0 1994 1995 1969 1994 1963 1994 1994 1985 1965 1994 75 RIO GRANGE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Hater 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 REMARKS.--Sediment samples were collected by a local observer on a weekly basis and during high flow events. Estimates for period of missing daily record were made from a sediment transport curve developed from a period of record over 5 years. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 20,400 mg/L November 27, 1968; minimum daily mean, 0 mg/L during water year 1985. SEDIMENT LOADS: Maximum daily, 167,000 tons (152,000 tonnes) May 18, 1985, minimum daily, <0.01 ton (<0.01 tonne) several days during many years. EXTREMES FOR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 2,590 mg/L September 16, 1995; minimum daily mean, 1.0 mg/L April 21, 1995. SEDIMENT LOADS: Maximum daily, 5,340 tons (4,840 tonnes) September 16,1995; minimum daily, eO.05 ton (0.04 tonne) April 20,1995. HATER-QUALITY DATA, HATER YEARS OCTOBER 1994 TO SEPTEMBER 1995 OCT 25 DEC 21 FEB 16 APR 20 •TON 22 SEP 18 OCT 25 CEC 21 FEB 16 APR 20 .TON 22 SEP 18 K * DATE TIME 1994 1400 1110 1995 1250 1045 1255 1025 HARD- NESS TOTAL (MG/L DATE AS CACO3) 1994 69 ... 1995 ... 68 ... 56 non-ideal count DIS- CHARGE, INST. CUBIC FEET PER SECOND 30 24 13 16 41 93 CALCIUM DIS- SOLVED (MG/L AS CA) 18 -- __ 17 -- 14 SPE- CIFIC CON- DUCT- ANCE (US/CM) 180 164 170 172 170 142 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 5.8 -- __ 6.2 __ 5.1 PH HATER WHOLE FIELD (STAND- ARD UNITS) 7.9 7.6 8.4 7.6 7.8 6.3 SODIUM, DIS- SOLVED (MG/L AS MA) 8.6 __ -- 8.0 -- 8.1 TEMPER- ATURE HATER (DBG C) 25.0 20.5 23.5 23.0 25.0 24.0 SODIUM AD- SORP- TION RATIO 0.5 — -- 0.4 — 0.5 TUR- BID- ITY (NTU) 4.0 20 2.3 3.3 6.5 28 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.2 __ __ 2.0 -- 2.8 OXYGEN, DIS- SOLVED (MG/L) 8.2 7.8 10.0 8.5 7.8 6.8 ALKA- LINITY HAT WH TOT FET FIELD MG/L AS CACO3 61 51 61 62 57 64 OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 100 87 118 103 97 83 SULFIDE TOTAL (MG/L AS S) <0.5 -_ -_ <0.5 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 <10 11 <10 <10 10 SULFATE DIS- SOLVED (MG/L AS S04) 13 — -- 13 -- 11 COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 270 K700 K45 230 K210 3000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 8.5 -- __ 8.7 -- 9.9 STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K150 630 K70 K110 420 3900 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 -- -- <0.10 -- <0.10 76 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR—Continued WATER-QUALITY DATA, WATER YEARS OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 25. . . DEC 21. .. FEB 1995 16. .. APR 20. . . JUN 22. .. SEP 18. .. DATE OCT 1994 25. .. DEC 21. . . FEB 1995 16. .. APR 20... JUN 22. .. SEP 18. .. SILICA, DIS- SOLVED (MG/L AS SI 02) 25 — — 24 — 23 COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 118 -- — 116 -- 100 IRON, TOTAL RECOV- ERABLE (UG/L AS FE) SOLIDS, DIS- SOLVED (TONS PER DAY) 9.37 — — 5.01 — 25.2 LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) RESIDUE TOTAL AT 105 DBG. C, SUS- PENDED (MG/L) 4 20 2 2 <1 53 MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.20 <0.20 <0.20 <0.20 <0.20 0.23 MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) PHOS- PHORUS TOTAL (MG/L AS P) 0.040 0.020 <0.010 <0.010 0.020 0.040 SELE- NIUM, TOTAL (UG/L AS SE) ARSENIC TOTAL (UG/L AS AS) <1 — — <1 — — SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) BORON, TOTAL RECOV- ERABLE (UG/L AS B) <10 — — 20 — — CYANIDE TOTAL (MG/L AS CN) CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- PHENOLS TOTAL (UG/L) CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 — — <1 -- -- METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) 310 210 50 20 <0.10 <0.10 <0.010 <0.010 <0.02 <0.02 RIO GRANDE DE ARECIBO BASIN 50026000 RIO TANAMA NEAR UTUADO, PR--Continu«d SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 77 DAY 1 2 3 4 5 6 7 e 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MEAN DISCHARGE (CPS) 23 23 19 17 17 32 32 69 40 80 68 119 64 107 44 34 36 55 36 35 37 36 31 28 42 31 30 32 26 25 25 MEAN CONCEN- TRATION (MG/L) OCTOBER 39 42 43 35 29 64 31 362 40 243 191 987 121 381 16 8 8 73 32 18 34 34 17 12 58 25 18 16 17 19 20 SEDIMENT DISCHARGE (TONS /DAY) 2.5 2.6 2.3 1.7 1.3 14 3.1 244 4.6 135 99.9 1310 23 454 2.1 .74 .78 12 3.1 1.7 3.9 3.5 1.4 .89 17 2.1 1.5 1.4 1.2 1.3 1.3 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) NOVEMBER MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) DECEMBER 32 25 24 24 22 21 21 21 25 26 22 20 20 19 19 19 24 22 47 39 22 20 19 19 63 32 23 21 22 21 33 19 19 16 14 12 9 8 12 19 13 12 10 9 8 8 16 16 158 58 17 17 19 20 317 103 59 23 16 13 4.2 1.3 1.2 1.1 .82 .66 .54 .43 1.2 1.3 .75 .64 .56 .48 .42 .40 1.5 .98 90 8.3 1.0 .94 .95 .99 160 9.1 3.7 1.3 .95 .75 23 37 24 21 21 20 19 19 19 18 19 19 19 19 18 27 93 49 39 34 24 22 21 21 23 23 22 22 21 20 20 15 56 53 31 23 18 17 17 16 14 12 11 8 5 4 24 457 74 63 53 41 30 25 21 17 13 11 11 10 8 6 1.2 6.5 3.5 1.8 1.3 .99 .90 .86 .79 .70 .62 .53 .40 .28 .20 5.1 621 14 19 5.3 2.7 1.8 1.4 1.2 1.0 .84 .67 .63 .57 .43 .35 TOTAL 1293 2353.91 754 296.46 796 696.56 78 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR DTUADO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCBN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY 20 19 19 18 17 18 17 16 17 16 15 15 17 18 24 25 18 18 17 17 19 22 18 17 17 40 26 22 20 18 18 7 7 9 10 12 11 11 10 8 6 5 5 5 5 28 20 9 8 7 6 7 7 8 7 6 41 17 8 5 5 6 .36 .37 .43 .50 .55 .55 .47 .42 .36 .27 .22 .21 .22 .24 6.5 1.6 .45 .37 .32 .28 .35 .43 .37 .33 .30 5.5 1.3 .47 .24 .25 .31 FEBRUARY 18 18 17 17 16 16 16 17 13 19 14 14 13 13 13 13 13 13 13 13 14 83 32 24 101 65 53 46 ___ ___ ___ 7 5 3 2 3 4 5 5 5 16 15 14 14 13 12 8 5 3 4 4 16 363 155 103 522 156 180 88 ___ ___ —— .35 .24 .15 .10 .12 .17 .21 .22 .18 .85 .59 .53 .49 .46 .42 .29 .17 .11 .13 .16 .63 425 14 6.8 376 53 27 18 ___ ___ ___ MARCH 55 35 40 39 38 e29 e44 e62 e33 e49 e35 e27 e35 e30 e27 e25 e24 e23 e22 e21 e20 e!9 el 9 el 9 e!9 el 8 e!8 e!7 el 8 e!7 e!7 114 32 57 40 40 29 26 27 26 25 24 23 21 15 11 8 7 6 6 5 5 4 3 2 2 3 3 3 4 4 4 19 3.0 11 4.4 5.8 e2.4 e2.9 e3.8 e3.2 e2.7 e2.7 el. 9 el. 7 el. 3 e.82 e.54 e.44 e.39 e.35 e.31 e.26 e.19 e.13 e.ll e.12 e.13 e.14 e.15 e.17 e.18 e.17 598 24.54 717 926.37 894 70.40 e Estimated RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MAY 79 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 e!7 e!6 e!6 e!6 e!5 e!5 e!6 e29 e36 e22 e25 e20 e!9 e!8 e!7 e!9 e23 e!8 e!5 e!7 e!5 e!5 e!4 e!4 el6 e!6 e!6 e!6 e!5 e!6 ___ APRIL 3 3 5 9 13 11 8 15 26 13 10 8 7 6 6 6 5 3 2 1 1 2 3 3 3 3 3 3 3 3 ___ e.15 e.15 e.23 e.37 e.55 e.43 e.34 e.95 e2.3 el.l e.64 e.51 e.37 e.31 e.28 e.29 e.30 e.18 e.08 e.05 e.06 e.08 e.ll e.ll e.12 e.13 e.13 e.13 e.12 e.13 ___ e!5 e!4 e!9 e60 e84 e29 e42 elOS ellO 90 94 84 71 73 204 121 69 68 76 75 58 47 44 41 47 42 47 39 41 41 64 3 3 6 75 128 30 22 30 1040 218 322 447 128 127 908 375 103 119 211 148 93 72 61 37 42 18 39 23 12 11 122 e.12 e.12 e.26 e8.3 e24 e4.6 e2.1 e5.5 el810 68 219 298 29 31 2270 178 20 28 89 59 15 9.2 7.2 4.0 6.2 2.0 5.2 2.4 1.4 1.3 50 MEAN DISCHARGE (CPS) 55 49 90 55 341 90 63 69 85 75 57 52 48 46 50 67 52 46 44 48 42 40 40 39 37 37 38 39 35 34 MEAN CONCEN- TRATION (MG/L) JUNE 61 63 436 75 1470 360 77 100 204 136 65 29 18 15 41 205 58 26 16 42 18 8 8 8 8 9 9 10 10 10 SEDIMENT DISCHARGE (TONS /DAY) 13 8.4 345 11 4260 106 13 22 67 31 10 4.2 2.3 1.9 6.5 84 8.2 3.2 1.9 6.9 2.1 .89 .86 .83 .82 .88 .96 1.1 .95 .91 542 10.70 2014 5247.90 1863 5015.80 e Estimated 80 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR 33 32 32 33 42 46 38 32 31 29 42 32 40 38 29 27 26 25 26 25 29 26 24 26 28 33 33 32 32 32 33 986 13805 JULY 10 10 10 14 66 82 120 19 12 10 57 52 55 43 22 19 18 17 16 16 25 23 9 12 24 25 20 17 15 13 12 —— AUGUST . 1. 12 18 13 1. 1. 13 4. 11 4. 1. 1. 1. 1. 1. 1. 2. 1. 1. 1. 2. 1. 1. 1. 1. 1. 107. 21813. 90 86 86 4 6 0 76 8 7 7 3 2 2 1 1 4 7 61 1 9 2 7 4 2 1 1 89 08 31 53 39 31 29 31 31 29 31 27 26 25 26 29 24 39 31 36 48 33 29 28 29 27 27 26 25 25 24 24 36 949 12 103 41 17 14 13 14 16 17 19 20 22 22 27 19 54 43 46 53 36 28 29 38 27 19 14 10 9 8 7 45 —— 1 35 4 1 1 1 1 1 1 1 1 1 1 2 1 9 3 4 7 3 2 2 3 2 1 11 110 .0 .5 .4 .1 .1 .2 .2 .4 .4 .4 .5 .7 .1 .3 .5 .6 .8 .4 .2 .2 .3 .0 .0 .4 .94 .67 .59 .50 .45 .85 MEAN DISCHARGE (CPS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) SEPTEMBER 25 24 55 33 49 133 110 53 61 45 87 50 e40 e36 61 412 114 89 78 72 71 64 103 75 63 67 96 98 71 64 —— 2399 23 17 117 30 66 512 311 71 143 56 380 118 35 22 152 2590 275 103 36 29 28 26 334 146 98 87 253 273 128 99 --- —— 1.6 1.1 38 2.8 12 319 106 11 48 7.2 311 17 e3.8 e2.2 64 5340 85 25 7.6 5.6 5.2 4.5 200 30 17 16 114 115 25 17 ___ 6951.6 e Estimated 81 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAHA NEAR UTUADO, PR--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DATE OCT 1994 12. .. 14. .. 14. .. NOV 25. .. FEB 1995 25. . . MAY 09. .. 12. .. JUN 03. ... 16. .. 16. .. 05. .. SEP 06. .. TIME 1625 1520 1655 1640 2045 1910 1955 1830 1659 1800 1700 1615 DIS- CHARGE, INST. CUBIC FEET PER SECOND 1260 982 184 204 214 e797 332 177 159 208 1670 173 SEDI- MENT, SUS- PENDED (MG/L) 4192 5478 2014 2541 3250 17900 8690 3610 5580 7192 23400 1059 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 14300 14500 1000 1400 1880 e38500 7790 1720 2400 4040 105000 494 SED. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 33 41 38 38 39 28 31 42 40 29 24 54 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 37 45 50 -- 50 34 47 53 50 45 29 64 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 39 52 54 54 63 39 55 60 59 55 34 72 DATE OCT 1994 12. .. 14. .. 14. .. NOV 25. .. FEB 1995 25. .. MAY 09. .. 12. .. JUN 03. .. 05. . . 16. .. 16. .. SEP 06. .. SED. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 47 64 63 73 73 52 71 70 44 70 71 79 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 61 74 69 84 82 64 80 80 54 80 82 88 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 83 86 77 95 95 77 96 94 64 94.7 91 97 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 97 95 84 98 98 91 98 98 78 98 98 99 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 98 98 89 99 99 95 99.5 99 89 99.3 99.6 99.6 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99 99 93 99.7 99.4 97.8 99.8 99.7 95 99.5 99.9 99.8 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 99.7 99.6 97 99.9 99.8 99 99.9 99.9 98.4 99.8 99.9 99.8 e Estimated 82 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DATE OCT 1994 06... 08... 10... 12.. . 12... 14.. . 15... NOV 25... DEC 18... JAN 1995 26.. . PEB 25... 25... MAR 07.. . MAY 05.. . 09.. . 09... 16.. . 19.. . JUN 03... 04.. . 05... 05.. . 16.. . AU6 03.. . 04.. . SEP 06. .. 06... 18... TIME 1432 1630 1350 1650 1805 1605 1640 1545 0840 1419 1645 1915 0820 0906 1815 2025 1640 1745 1715 0829 1800 2310 1710 1219 0829 1235 1425 0839 STREAM- PLOW, INSTAN- TANEOUS (CPS) 16 250 395 784 277 416 40 312 46 54 415 361 e44 e84 e2730 e286 256 231 461 53 651 188 239 37 53 347 217 95 SEDI- MENT, SUS- PENDED (MG/L) 238 4980 1870 12100 7530 2220 2330 2290 233 110 1430 2970 191 126 6750 4870 5510 2730 3910 132 5230 1370 1620 254 132 550 1150 94 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 10 3360 1990 25600 5630 2471 252 1930 29 16 1600 2890 e22 e28 649700 «3760 3810 1700 4870 9 9190 695 1040 25 19 515 673 24 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 99 94 95 93 97 96 73 93 93 95 86 95 99 98 72 92 79 95 85 96 88 95 72 96 96 91 94 94 e Estimated RIO GRANDE DE ARECIBO BASIN 50029400 RIO TANAMA AT CHARCO HONDO, PR LOCATION.--Lat 18°24'52", long 66°42'52", Hydrologic Unit 21010002 on right bank at 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.--57.6 mi 1 (149.2 km>)• 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 (19 m), from topographic map. REMARKS.--Records poor. Diversion 0.8 mi (1.3 km) upstream for municipal supply of Arecibo. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 83 OCT DEC JAN FEE MAR APR MAY JUL AUG SEP 1 49 e48 2 47 85 3 47 e46 4 44 e44 5 40 e46 6 55 e43 7 69 e45 8 92 e44 9 105 e43 10 214 e46 11 232 e47 12 e!80 e43 13 135 e41 14 232 e41 15 265 e40 16 91 e38 17 80 37 18 109 48 19 93 38 20 119 107 21 137 46 22 223 41 23 97 39 24 81 39 25 99 75 26 91 90 27 e60 63 26 e56 50 29 e62 49 30 e48 49 31 e46 --- TOTAL 3299 1512 MEAN 106 50.4 MAX 265 107 M1N 40 37 AC-PT 6520 3000 CFSM 1.84 .87 IN. 2.12 .98 STATISTICS OF MONTHLY MEAN MEAN 161 135 MAX 335 260 (WY) 1990 1982 MIN 72.1 50.4 (WY) 1983 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 46 83 85 56 48 49 46 46 44 41 40 40 40 40 38 39 90 156 54 90 49 49 43 39 39 37 39 39 39 39 40 1619 52.2 156 37 3210 .91 1.05 DATA 79.1 219 1982 36.4 1989 FOR e37 e37 e34 e32 e34 e32 e30 e32 e30 e28 627 29 30 36 29 51 31 29 29 30 33 53 33 30 30 65 62 40 35 31 30 1099 35.1 65 27 2160 .61 .70 FOR WATER 53.7 90.8 1982 22.3 1989 29 29 28 28 27 27 28 31 31 35 29 e29 «31 e29 e28 e27 e29 e28 e28 e29 e29 e31 e210 e56 e96 e370 e!39 e75 ___ ___ --- 1596 56.6 370 27 3150 .98 1.02 YEARS 1969 45.7 85.1 1971 16.7 1989 e78 e350 e74 e90 e58 e60 e57 90 130 69 98 73 e56 72 e62 e54 e52 e50 e48 e46 e44 e42 e40 e39 e39 e38 e37 e37 e36 e36 e35 2079 67.1 350 35 4120 1.16 1.34 - 1995 40.9 70.0 1971 16.6 1988 1994 CALENDAR YEAR 16257 44. 265 20 21 32250 10. 80 34 24 5 Oct 15 Jul 27 Jul 22 77 50 e34 e34 e33 e33 e33 e31 e31 e31 e47 e76 e45 e53 e42 e39 e36 e34 e38 e48 e36 e30 35 30 30 29 29 32 33 33 32 31 --- 1098 36.6 76 29 2180 .64 .71 33 31 29 31 125 176 62 87 221 234 190 226 211 329 403 420 332 205 321 237 162 ellO e!30 ellO e!30 ellO e!60 256 303 245 299 5917 191 420 29 11740 3.31 3.92 325 218 226 183 632 474 269 292 314 431 373 282 e!91 150 138 151 e!43 elOO e94 e90 e96 e86 e90 e90 e78 e74 e74 e76 e79 e72 --- 5969 196 632 72 11640 3.40 3.79 e72 e72 e70 e72 e92 e90 e94 e90 59 56 54 79 58 105 76 56 59 61 52 55 59 65 55 55 59 52 51 52 56 50 51 2016 65.0 105 50 4000 1.13 1.30 55 68 84 56 51 93 154 95 108 88 60 52 51 57 53 53 76 63 98 81 109 149 95 67 61 54 53 52 51 51 67 2294 74.0 154 51 4550 1.28 1.48 72 52 73 85 68 266 368 197 107 115 127 115 82 72 73 1090 511 302 186 165 165 156 242 266 162 162 231 290 213 162 --- 6165 205 1090 52 12230 3.57 3.99 , BY WATER YEAR (WY) 68.1 141 1986 25.9 1989 FOR 1995 34532 94 1090 27 28 4430 12 69490 1 22 224 56 31 136 371 1986 15.8 1989 WATER YEAR .6 Sep 16 Jan 11 Feb 1 Jun 6 .89 Jun 6 .64 .30 91.2 196 1995 23.3 1989 65.2 120 1969 22.0 1989 WATER 86 124 46 2500 4 5 15000 17 62590 1 20 176 63 27 72.3 125 1991 35.1 1994 YEARS 1969 .4 .9 Oct .2 May .4 May May .95 May .50 .39 117 216 1984 44.9 1994 - 1995 1986 1994 7 1995 29 1989 22 1989 18 1995 19 1985 e Estimated 84 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, 8.3 mi (13.4 km) downstream from Dos Bocas Reservoir, 1.9 mi (3.1 km) downstream from Rio TananuS ,_ and 1.6 mi (2.6 km) southeast of Arecibo. DRAINAGE AREA.--200 mi 1 (520 km')/ approximately. PERIOD OF RECORD.—Water years 1963-66, 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 28. .. JAN 1995 13. .. FEB 21. . . APR 21. .. JUN 16. .. SEP 13. .. DATE OCT 1994 28. . . JAN 1995 13. .. FEB 21. .. APR 21. .. JUN 16. . . SEP 13. .. DATE OCT 1994 28. .. JAN 1995 13. .. FEB 21... APR 21... JUN 16. .. SEP 13. .. TIME 1220 0810 1215 1145 0945 0915 HARD- NESS TOTAL (HG/L AS CACO3) 120 -- -- 130 -- 120 SILICA, DIS- SOLVED (HG/L AS SIO2) 16 — — 14 -- 17 DIS- CHARGE, INST. CUBIC FEET PER SECOND 187 161 75 65 E300 E150 CALCIUM DIS- SOLVED (MG/L AS CA) 39 -- -- 40 -- 39 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 164 -- -- 160 -- 154 SPE- CIFIC CON- DUCT- ANCE (US/CM) 273 276 280 278 290 250 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 6.1 — -- 6.3 -- 5.3 SOLIDS, DIS- SOLVED (TONS PER DAY) 82.6 — — 27.8 — — PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.9 7.6 7.8 7.9 7.8 7.2 SODIUM, DIS- SOLVED (MG/L AS NA) 9.6 -- -- 8.7 __ 9.1 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 14 4 <1 3 20 15 TEMPER- ATURE WATER (DEG C) 28.0 23.0 25.0 27.0 25.0 26.0 SODIUM AD- SORP- TION RATIO 0.4 — __ 0.3 __ 0.4 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.30 <0.20 <0.20 <0.20 0.23 0.35 TUR- BID- ITY (NTU) 6.7 2.1 1.2 1.7 13 2.5 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.0 -- -- 1.6 __ 2.1 PHOS- PHORUS TOTAL (MG/L AS P) 0.060 0.030 <0.010 <0.010 0.030 0.180 OXYGEN, DIS- SOLVED (MG/L) 8.9 6.4 8.6 9.7 6.4 5.2 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 110 100 120 110 120 140 ARSENIC TOTAL (UG/L AS AS) <1 -- — <1 — — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 112 73 103 122 77 63 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 __ -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 10 <10 23 <10 <10 16 SULFATE DIS- SOLVED (MG/L AS SO4) 13 -- — 11 -- 10 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 10 -- — 40 -- — COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 600 270 K680 K54 K910 2700 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 12 -- -- 12 -- 11 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K130 240 K120 K150 510 2900 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 -- -- 0.10 -- 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- — <1 -- — K s non-ideal count E m Estimated 85 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) IRON, TOTAL RECOV- ERABLE (UG/L AS FE) LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MM) MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) SELE- NIUM, TOTAL (UG/L AS SE) SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) CYANIDE TOTAL (MG/L AS CN) PHENOLS TOTAL (UG/L) METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) OCT 1994 28. . . JAN 1995 13. .. FEB 21. .. APR 21. .. JUN 16. .. SEP 13. .. 270 160 30 10 <0.10 <0.10 <0.010 <0.010 <0.02 0.02 PESTICIDE ANALYSES DATE JUN 1995 16. .. JUN 1995 16.. . DATE CHLOR- DANE, P,P'- P,P'- ENDO- TECH- ODD DOT DI- DI- SULFAN, PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I TIME 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) 0945 <0 ENDRIN WATER UNFLTRD REC (UG/L) <0.010 PARA- THION, TOTAL (UG/L) .100 <0. ETHION, TOTAL (UG/L) <0.010 PCNS UNFILT RECOVER (UG/L) 010 <0 HEPTA- CHLOR, TOTAL (UG/L) <0.010 PER- THANE TOTAL (UG/L) .100 <0 HEPTA- CHLOR EPOXIDE TOTAL (UG/L) <0.010 TOX- APHENE, TOTAL (UG/L) .010 <0, LINDANE TOTAL (UG/L) <0.010 TOTAL TRI- THION (UG/L) .010 <0 MALA- THION, TOTAL (UG/L) <0.010 2,4-D, TOTAL (UG/L) .010 <0 METH- OXY- CHLOR, TOTAL (UG/L) <0.010 2,4,5-T TOTAL (UG/L) .010 <0, METHYL PARA- THION, TOTAL (UG/L) <0.010 2, 4 -DP TOTAL (UG/L) .010 <0.010 MIREX , TOTAL (UG/L) <0.010 SILVEX, TOTAL (UG/L) JUN 1995 16.. . <0.010 <0.100 <0.100 <1.00 <0.010 <0.010 <0.010 <0.010 <0.010 86 THIS PAGE WAS LEFT BLANK INTENTIONALLY EXPLANATION A0350 SURFACE-WATER STATION AND NUMBER Toso7 QUALITY-OF-WATER STATION AND NUMBER • 210 WELL AND WELL NUMBER 1032290 LAKE-ELEVATION STATION AND NUMBER Figure 16.--Rfo Grande de Manatf basin. 88 RI° GRANDE DE HANATI 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 Rio Botijas, and 250 ft (76 m) upstream from bridge on Highway 599. DRAINAGE AREA.—5.03 mi a (13.03 km2 ). WATER-DISCHARGE RECORDS 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT NOV 1 .69 .88 2 .68 13 3 .72 12 4 .69 .86 5 .67 .91 6 .66 2.3 7 .68 1.5 8 .74 .89 9 1.2 .77 10 .84 .74 11 .76 .74 12 .69 .71 13 .69 .69 14 5.4 .68 15 4.1 .66 16 .80 .64 17 .83 .64 18 2.9 .61 19 1.1 .61 20 .92 .61 21 1.3 .60 22 2.5 .59 23 167 .58 24 14 .50 25 3.4 .56 26 1.5 .57 27 1.2 .57 28 1.1 .72 29 1.0 .66 30 1.0 .96 31 .92 —— TOTAL 220.68 46.75 MEAN 7.12 1.56 MAX 167 13 MIN .66 .50 AC-FT 438 93 CFSM 1.42 .31 IN. 1.63 .35 DEC .75 .68 .69 .70 .69 .69 .69 .66 .67 .65 .68 .66 .67 .65 .65 .65 .61 .61 .61 .61 .61 .61 .61 .61 .65 .68 .62 .73 .64 .61 .61 20.25 .65 .75 .61 40 .13 .15 STATISTICS OF MONTHLY MEAN DATA MEAN 18.3 6.41 MAX 58.0 15.2 (WY) 1990 1991 MIN 1.95 1.56 (WY) 1994 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 5.18 15.8 1982 .65 1995 FOR JAN .61 .60 .57 .59 .60 .58 .59 .61 .64 .73 .78 .63 .67 .72 .74 .76 .78 .78 .78 .78 .80 .80 .78 .76 .71 1.6 1.0 1.3 .90 .92 .73 23.84 .77 1.6 .57 47 .15 .18 FOR WATER 6.24 34.3 1992 .77 1995 FEB .69 .65 .65 .67 .65 .63 .61 .61 .63 .61 .59 .58 .56 .54 .59 .61 .61 .61 .64 .68 .68 .72 .66 .61 .65 5.3 4.5 1.3 —— ___ —— 26.83 .96 5.3 .54 53 .19 .20 YEARS 1981 2.09 2.97 1992 .96 1995 MAR .97 .86 .84 .84 .80 .81 .78 .82 .81 .89 3.1 2.1 9.9 6.4 2.8 .97 .81 .73 .66 .62 .60 .59 .58 .53 .51 .49 .51 .49 .44 e.44 e.44 42.13 1.36 9.9 .44 84 .27 .31 - 1995 1.68 2.46 1990 .90 1994 1994 CALENDAR YEAR 623. 1. 167 m 1240 4. 1. . 94 71 Oct 23 50 NOV 24 57 Nov 21 34 61 7 94 67 APR .45 .50 .47 .46 .47 .47 .48 .48 .48 .47 .50 8.2 .91 .71 .67 1.1 1.3 .87 .76 .72 .70 .75 .78 .79 .76 .75 .75 .74 .75 .74 —— 27.98 .93 8.2 .45 55 .19 .21 MAY .71 .74 1.7 5.4 37 25 165 242 206 186 56 6.7 4.5 6.4 45 45 19 10 11 29 43 18 8.4 8.6 11 33 65 42 13 49 31 1424.15 , BY WATER 5.82 21.0 1993 .93 1995 FOR 1995 3764 10 445 1550 10 7470 2 27 18 45.9 242 .71 2820 9.13 10.53 YEAR (WY) 16.6 45.9 1995 1.42 1989 JUN 12 6.6 11 6.1 3.6 4.4 4.3 3.6 2.5 3.6 3.3 2.7 2.5 1.9 2.2 2.5 3.0 3.9 3.5 2.7 3.7 4.0 5.2 5.1 4.4 4.3 29 23 5.3 3.1 —— 173.0 5.77 29 1.9 343 1.15 1.28 4.97 15.2 1992 .88 1994 WATER YEAR .67 .3 .44 .46 .34 .05 .84 .82 .60 Sep 16 Mar 29 Mar 29 May 8 May 8 JUL 2.3 1.9 1.7 1.7 1.3 1.2 1.3 1.4 1.3 1.0 1.3 1.7 2.4 1.7 2.0 1.5 1.7 2.1 2.4 1.1 1.2 1.3 1.3 1.1 .99 .89 .93 .94 .94 .85 .93 44.37 1.43 2.4 .85 88 .28 .33 3.18 8.40 1991 .88 1994 WATER 7 10 1 445 2320 11 5320 1 19 12 1 AUG .68 .65 1.0 .70 .64 .64 .68 .71 .70 .66 .62 .67 6.3 1.0 .65 .66 .66 1.3 8.2 1.3 1.1 .83 .88 .83 .81 .81 .77 29 23 1.2 .67 88.32 2.85 29 .62 175 .57 .65 3.93 12.3 1989 1.03 1982 YEARS 1981 .34 .3 .49 Sep .20 Oct .33 Oct Jan .53 Jan .46 .84 .8 .84 SEP .72 .72 1.3 .73 20 205 147 200 35 19 15 11 2.9 1.4 27 445 185 87 39 22 15 11 10 8.7 6.6 6.3 54 33 9.9 7.1 —— 1626.37 54.2 445 .72 3230 10.8 12.03 15.6 54.2 1995 .88 1994 - 1995 1995 1994 16 1995 4 1992 11 1992 5 1992 5 1992 e Estimated 89 LOCATION.—Lat 18°14 (1.6 km) north of DRAINAGE AREA.--10.1 PERIOD OF RECORD.--W« RIO GRANDE DE MANATI BASIN 50030700 RIO OROCOVIS NEAR OROCOVIS, PR WATER-QUALITY RECORDS 20", long 66°22'58", at flat low bridge about 300 ft (91 m) northwest of Highway 568, 1.0 mi Orocovis plaza. mi* (26.2 km1 ). iter year 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 20. . . DEC 13. .. FEB 1995 09... APR 19. .. JUN 14. .. AUG 29. . . DATE OCT 1994 20. .. DEC 13. .. FEB 1995 09... APR 19. .. JUN 14. .. AUG 29... DATE OCT 1994 20. .. DEC 13. .. FEB 1995 09. .. APR 19. .. JUN 14... AUG 29. . . TIME 1500 1230 1110 1155 1300 0750 HARD- NESS TOTAL (MG/L AS CAC03) 150 -- — 160 -- 87 SILICA, DIS- SOLVED (MG/L AS SI02) 32 -- -- 28 -- 23 DIS- CHARGE, INST. CUBIC FEET PER SECOND 2.9 1.9 2.3 2.3 5.2 13 CALCIUM DIS- SOLVED (MG/L AS CA) 40 -- -- 43 -- 21 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 228 -- __ 228 -- 137 SPE- CIFIC CON- DUCT- ANCE (US /CM) 359 360 367 381 343 208 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 12 — -- 13 -_ 8.4 SOLIDS, DIS- SOLVED (TONS PER DAY) 1.80 -- __ 1.42 — 4.67 PH WATER WHOLE FIELD (STAND- ARD UNITS) 8.0 8.1 7.9 8.0 8.0 6.9 SODIUM, DIS- SOLVED (MG/L AS NA) 16 -_ -_ 18 -_ 9.7 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 8 3 2 3 1 82 TEMPER- ATURE WATER (DEG C) 23.0 22.0 21.0 23.5 26.0 22.0 SODIUM AD- SORP- TION RATIO 0.6 _- — 0.6 __ 0.5 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 <0.20 <0.20 <0.20 0.32 0.67 TUR- BID- ITY (NTU) 1.9 1.8 0.50 2.0 0.40 88 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 1.7 __ __ 1.9 __ 1.9 PHOS- PHORUS TOTAL (MG/L AS P) 0.170 0.240 0.200 0.300 0.340 0.080 OXYGEN, DIS- SOLVED (MG/L) 7.2 9.2 8.2 8.6 7.0 3.5 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 150 160 160 150 150 84 ARSENIC TOTAL (UG/L AS AS) 1 -- -- <1 -- — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 87 109 96 107 91 42 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 -- — — BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 <10 11 <10 <10 17 SULFATE DIS- SOLVED (MG/L AS SO4) 16 -- — 12 — 10 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 40 -- -- 50 -- — COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 250 K45 K27 2700 K740 21000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 20 -- -- 22 -- 13 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS . PER 100 ML) 800 340 450 320 K390 19000 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 -- — <0.10 -- <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 -- — K = non-ideal count 90 RIO GRANDB DE MANATI BASIN 50030700 RIO OROCOVIS NEAR OROCOVIS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS PE) AS PB) AS MM) AS HG) AS SB) AS AG) AS ZN) AS CN) (UG/L) OCT 1994 20. .. DEC 13. ., PEB 1995 09... APR 19. .. JUN 14. .. AUG 29. .. 120 160 20 <0.10 30 <0.10 <0.010 <0.010 (MG/L) <0.02 0.04 91 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR LOCATION.--Lat 18 e 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 Rio Sana Muerto, and 2.2 mi (3.5 km) south of Morovis. DRAINAGE AREA.--55.2 mi 2 (143.0 km1 )- WATER-DISCHARGE RECORDS PERIOD OP RECORD.--January 1965 to current year. 6A6B.--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 pumpage, about 300 ft (91 m) above the station, influences low-flow discharges. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT JON JUL AUG 1 4.0 10 2 4.0 9.1 3 4.0 9.5 4 3.6 12 5 23 20 6 7.2 16 7 8.4 13 8 7.8 13 9 5.7 16 10 28 14 11 47 12 12 29 17 13 37 e!5 14 41 11 15 30 9.5 16 15 9.0 17 9.1 8.8 18 29 8.6 19 29 7.6 20 48 8.9 21 20 8.7 22 28 9.5 23 138 8.9 24 75 8.2 25 31 7.6 26 18 8.6 27 13 9.1 28 11 9.9 29 10 12 30 9.5 21 31 9.8 --- TOTAL 773.1 343.5 MEAN 24.9 11.4 MAX 138 21 MIN 3.6 7.6 AC-FT 1530 681 CFSM .45 .21 IN. .52 .23 STATISTICS OF MONTHLY MEAN MEAN 157 145 MAX 1037 491 (WY) 1971 1971 MIN 24.0 11.4 (WY) 1978 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAR FLOW INSTANTANEOUS PEAR STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 29 19 13 16 12 12 12 11 10 8.7 7.7 7.1 6.9 6.3 6.3 6.3 6.3 6.0 5.7 5.5 5.3 5.2 4.9 4.8 4.7 5.3 7.1 6.9 6.6 5.6 5.0 268.2 8.65 29 4.7 532 .16 .18 DATA 111 522 1966 8.65 1995 FOR 5.0 5.9 5.4 5.2 5.3 4.9 4.7 4.3 4.5 6.6 9.6 8.7 9.1 8.6 6.7 5.7 5.4 5.5 5.3 5.3 5.9 4.9 4.9 4.6 4.4 39 47 36 29 15 11 323.4 10.4 47 4.3 641 .19 .22 FOR WATER 77.9 191 1992 10.4 1995 8.8 8.0 .6.8 6.5 6.0 6.0 5.7 6.0 7.5 9.6 7.4 6.6 5.6 5.9 6.3 5.6 5.6 6.5 8.1 8.3 8.2 8.8 8.5 6.6 31 77 172 100 ___ ___ --- 548.9 19.6 172 5.6 1090 .36 .37 YEARS 1965 62.8 179 1969 15.3 1994 63 31 19 14 12 10 8.8 e8.8 e8.6 e8.4 e64 638 e40 e58 e60 640 623 el7 6 14 612 ell 69.4 e8.6 7.7 7.0 6.6 6.3 7.0 6.7 5.8 5.6 631.3 20.4 64 5.6 1250 .37 .43 - 1995 65.7 226 1972 12.7 1984 1994 CALENDAR YEAR 5103. 14. 138 3. 4. 10120 . 3. 29 10 5. 3 0 Oct 23 6 Oct 4 0 Jul 22 25 44 2 5.3 .9 .3 .3 .3 .4 .0 3.8 5.3 6.4 5.1 48 33 13 10 11 16 14 8.5 6.9 6.1 6.7 7.0 5.6 5.1 4.8 4.1 3.9 3.8 4.3 --- 263.9 8.80 48 3.8 523 .16 .18 3.5 4.6 9.6 59 115 47 247 285 268 251 222 100 73 157 490 278 138 158 166 268 176 98 60 41 31 54 124 150 65 90 119 4347.7 140 490 3.5 8620 2.54 2.93 54 40 60 e43 e37 e33 629 627 625 e24 625 e23 621 e!6 15 14 14 13 11 11 10 10 9.2 8.3 7.8 7.7 20 120 33 18 --- 779.0 26.0 120 7.7 1550 .47 .52 18 13 13 16 15 14 13 12 11 11 11 13 13 38 25 23 15 13 13 13 16 24 20 15 12 11 12 21 41 24 22 531 17.1 41 11 1050 .31 .36 15 13 18 26 15 13 12 11 11 10 9.8 9.3 8.8 24 21 16 17 15 18 19 14 12 15 31 33 20 16 14 85 27 18 586.9 18.9 85 8.8 1160 .34 .40 31 33 38 63 38 531 348 512 182 102 64 69 53 38 71 1340 426 254 134 100 85 78 67 74 55 48 86 128 72 51 --- 5171 172 1340 31 10260 3.12 3.48 , BY WATER YEAR (WY) 110 412 1969 8.80 1995 FOR 1995 14567 39 1340 3 4 2870 5 28900 9 85 13 5 165 915 1985 15.7 1994 WATER YEAR .9 .9 Sep 16 .5 May 1 .1 Apr 26 Sep 16 .90 Sep 16 .72 .82 .3 62.4 173 1987 6.75 1994 46.7 157 1979 5.54 1994 WATER 95 248 24 17100 3 4 48000 17 69370 1 23 173 49 21 56.0 435 1979 9.70 1984 YEARS 1965 .8 .2 May .5 May .0 Jul May .89 May .73 .57 93.1 386 1979 6.87 1994 - 1995 1971 1994 18 1985 1 1995 22 1994 18 1985 18 1985 e Estimated 92 PERIOD RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI HEAR MOROVTS, PR--Continued WATER-QUALITY RECORDS OP RECORD.--Water years 1968 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 WATER-QUALITY DATA DATE OCT 1994 20. .. DEC 13. .. FEB 1995 09. . . APR 19. .. JUN 14. .. AUG 29. .. DATE OCT 1994 20. .. DEC 13. .. FEB 1995 09. .. APR 19. , . JUN 14. .. AUG 29. . . TIME 1250 1420 0925 0935 1045 0935 HARD- NESS TOTAL (HG/L AS CACO3) 120 __ -- 130 -- 130 SILICA, DATE OCT 1994 20. .. DEC 13. .. FEB 1995 09. .. APR 19. . . JUN 14. .. AUG 29. .. K = non- ideal DIS- SOLVED (HG/L AS SIO2) 24 -- -- 24 — 28 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 39 7.1 6.6 8.3 16 115 CALCIUM DIS- SOLVED (MG/L AS CA) 28 __ -- 31 __ 31 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 173 -- -- 183 -- 197 SPE- CIFIC CON- DUCT- ANCE (US/CM) 275 317 315 316 291 332 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 11 __ — 12 __ 12 SOLIDS, DIS- SOLVED (TONS PER DAY) 18.2 — -- 4.08 -- 61.2 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.9 8.2 7.6 7.9 8.1 7.4 SODIUM, DIS- SOLVED (MG/L AS NA) 13 __ -- 14 __ 14 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 44 10 5 4 3 154 TEMPER- ATURE WATER (DEG C) 25.0 25.5 22.5 25.0 28.0 27.0 SODIUM AD- SORP- TION RATIO 0.5 __ — 0.5 __ 0.5 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.30 <0.20 <0.20 <0.20 0.26 0.64 TUR- BID- ITY (NTU) 48 7.9 3.6 1.3 0.60 82 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.3 __ -- 2.0 __ 2.7 PHOS- PHORUS TOTAL (MG/L AS P) 0.070 0.040 0.040 0.030 <0.020 0.180 OXYGEN, DIS- SOLVED (MG/L) 7.0 8.5 7.6 7.7 8.2 4.5 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CACO3 100 130 130 120 130 140 ARSENIC TOTAL (UG/L AS AS) 1 — -- <1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 84 103 88 95 106 57 SULFIDE TOTAL (MG/L AS S) <0.5 __ -- <0.5 __ -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 __ -- <100 — -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 13 <10 <10 <10 <10 18 SULFATE DIS- SOLVED (MG/L AS SO4) 16 — __ 9.8 -- 8.5 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 30 — -- 40 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 3500 K110 260 5200 K140 2900 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 19 __ -- 18 __ 17 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 4100 K210 240 K170 K40 3100 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 __ — 0.10 -- 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 4 -- -- <1 -- -- 93 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 20... DEC 13... FEB 1995 09. .. APR 19. .. JUN 14. .. AUG 29... MANGA- METHY- COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CU) AS FE) AS PB) AS MM) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) 10 1700 1 90 <0.10 <1 <1 <10 <0.010 2 <0.02 — __ 10 150 <1 40 <0.10 <1 <1 <10 <0.010 <1 0.03 _- __ 94 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 Rio 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 mi 1 (4.25 km 1 ). 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 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 Rio 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.l, 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 2,966 ft (904 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 2,961.70 ft (902.73 m), Oct. 21, 1990; minimun elevation, 2,919.79 ft (899.95 m), May 27, 1988. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 2,961.12 ft (902.54 m), Sep. 27; minimun elevation, 2,930.70 ft (893.28 m), July 21. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet 2,872 2,919 2,925 Contents, in acre-feet 0 361 491 Elevation, in feet 2,943 2,950 2,961 Contents, in acre-feet 1,029 1,308 1,852 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX MIN OCT DEC JAN FEB MAR APR MAY JUL AUG SEP 2936.50 2936.59 2936.66 2936.73 2936.80 2937.08 2937.20 2944.33 2944.76 2945.01 2945.20 2945.34 2945.46 2946.25 2946.48 2946.63 2946.90 2947.31 2947.48 2947.64 2947.78 2948.33 2949.52 2950.60 2951.20 2951.52 2951.80 2952.02 2952.20 2952.36 2952.50 2952.50 2936.50 2952.66 2953.60 2953.83 2954.00 2954.15 2954.32 2954.46 2954.57 2955.27 2955.48 2955.63 2955.77 2955.91 2956.02 2956.12 2956.22 2956.32 2956.42 2956.52 2956.61 2956.70 2956.78 2956.85 2956.92 2957.16 2957.24 2957.31 2957.38 2957.45 2957.53 --- 2957.53 2952.66 2957.59 2957.64 2957.74 2957.81 2957.34 2956.98 2957.03 2957.07 2957.11 2957.16 2957.21 2957.26 2956.85 2956.64 2956.66 2956.68 2956.72 2956.76 2956.80 2956.86 2956.89 2956.94 2957.02 2957.08 2957.18 2957.22 2957.27 2957.29 2956.96 2956.61 2956,65 2957.81 2956.61 2956.69 2956.71 2956.75 2956.53 2956.25 2956.28 2956.30 2956.32 2956.34 2956.36 2956.38 2956.40 2956.16 2956.17 2956.18 2956.20 2955.80 2955.82 2955.84 2955.04 2955.07 2955.08 2955.10 2955.12 2955.14 2955.21 2955.22 2955.25 2955.26 2955.28 2954.46 2956.75 2954.46 2953.78 2953.80 2953.81 2953.82 2953.83 2953.84 2953.95 2953.99 2954.04 2954.06 2954.07 2954.08 2954.09 2954.10 2954.12 2954.13 2954.14 2954.15 2954.18 2954.19 2954.77 2954.78 2954.81 2955.00 2955.29 2956.20 2956.35 2957.14 ___ ___ --- 2957.14 2953.78 2958.72 2959.00 2959.15 2959.36 2959.48 2959.06 A A A A A A A A A A A A A 2954.50 2953.97 2954.04 2953.59 2952.96 2953.01 2953.06 2952.28 2951.43 2950.61 2950.06 2949.43 ___ 2949.47 2949.51 2949.39 2948.46 2947.41 2946.64 2945.69 2945.74 2945.79 2944.89 2944.05 2943.66 2942.70 2942.73 2942.80 2942.86 2943.00 2942.62 2942.25 2941.78 2941.80 2941.84 2941.85 2941.31 2940.68 2939.47 2938.40 2937.21 2937.24 2937.31 2949.51 2937.21 2936.65 2935.61 2934.28 2933.09 2932.64 2931.53 2933.19 2933.67 2937.97 2937.95 2937.09 2936.30 2936.50 2936.67 2936.34 2935.85 2935.99 2935.97 2935.76 2935.93 2936.05 2935.04 2934.23 2934.01 2934.10 2933.93 2935.10 2935.38 2935.82 2936.12 2936.37 2937.97 2931.53 2936.56 2936.01 2936.40 2936.62 2936.83 2935.76 2935.23 2934.84 2934.08 2933.42 2932.94 2932.36 2931.93 2931.83 2931.97 2932.09 2932.21 2932.33 2932.44 2932.53 2932.43 2932.27 2932.09 2932.19 2932.27 2932.41 2932.76 2932.63 2932.60 2932.57 --- 2936.83 2931.83 2932.64 2932.72 2932.61 2932.68 2932.57 2932.52 2932.37 2932.45 2932.51 2932.42 2932.48 2932.40 2932.38 2932.31 2932.55 2932.66 2932.47 2932.30 2931.91 2931.75 2931.51 2931.62 2931.69 2931.77 2931.83 2931.54 2931.62 2931.67 2931.81 2934.38 2934.61 2934.61 2931.51 2934.72 2934.90 2935.08 2935.18 2935.28 2935.55 2935.71 2935.84 2935.95 2936.05 2936.14 2936.21 2936.32 2936.40 2936.50 2936.68 2936.88 2939.09 2939.94 2940.78 2941.17 2941.42 2941.66 2941.88 2942.07 2942.22 2942.38 2942.50 2942.63 2942.77 2942.89 2942.89 2934.72 2943.01 2943.13 2943.24 2943.36 2943.67 2945.93 2947.35 2948.20 2948.56 2948.86 2949.15 2949.43 2949.63 2949.84 2950.81 2954.23 2956.34 2957.19 2957.76 2958.42 2958.88 2959.26 2959.91 2960.34 2960.66 2960.78 2960.84 2960.74 2960.32 2959.96 ___ 2960.84 2943.01 A No gage-height record 95 RIO GRANDE DE MANATI BASIN 50032590 LAGO DE MATRULLAS AT DAMSITE NEAR OROCOVIS, PR LOCATION.—Lat 18°12 / 46 n , long 66°28'50", Hydrologic Unit 21010001, in concrete house at damsits, and 5.8 mi (9.3 km) southwest of Orocovis. DRAINAGE AREA.--4.46 mi> (11.55 km1 ). ELEVATION RECORDS PERIOD OP RECORD.--May 1988 to current year. Prior to October 1994, published as Lago de Matrullas at Damsits. 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 hmj ) 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 Diaz Canal. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,413.56 ft (735.65 m), Jan. 6, 1992; minimum elevation, 2,375.55 ft (724.06 m), Sept. 24, 25, 1994. EXTREMES OBSERVED FOR CURRENT YEAR.—Maximum elevation, 2,395.62 ft (730.18 m), Apr. 3; minimum elevation, 2,375.91 ft (724.18 m), Oct. 1. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet 2,338 2,360 Contents, in acre-feet 2 302 Elevation, in feet 2,399 2,415 Contents, in acre-feet 1,845 2,945 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES DEC DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX MIN CAL YR 1994 MAX 2411.98 MIN 2375.55 A No gage-heigt record JAN FEB MAR APR 2376.06 2376.19 2376.27 2376.34 2376.36 2376.46 2376.56 2376.63 2376.82 2377.10 2377.27 2377.55 2377.83 2378.16 2378.70 2378.93 2379.09 2379.49 2379.77 2379.95 2380.06 2380.17 2381.87 2382.51 2383.02 2383.22 2383.41 2383.58 2383.71 2383.84 2383.96 2383.96 2376.06 2384.05 2384.29 2384.81 2385.04 2385.17 2385.29 2385.42 2385.56 2385.66 2385.74 2385.82 2385.92 2385.97 2385.74 2385.27 2384.73 2384.25 2383.80 2383.64 2383.68 2383.56 2383.12 2382.53 2382.26 2382.23 2382.29 2382.40 2382.23 2382.07 2381.90 —— 2385.97 2381.90 2381.78 2381.81 2381.93 2382.02 2382.08 2382.16 2382.21 2382.29 2382.33 2382.38 2382.43 2382.48 2382.50 2382.43 2382.41 2382.43 2382.47 2382.51 2382.55 2382.60 2382.65 2382.71 2382.78 2382.84 2382.91 2383.01 2383.08 2383.13 2383.19 2383.26 2383.31 2383.31 2381.78 2383.37 2383.43 2383.49 2383.56 2383.61 2383.66 2383.70 2383.76 2383.81 2383.89 2383.98 2384.07 2384.14 2384.20 2384.25 2384.31 2384.34 2384.39 2384.43 2384.16 2384.03 2384.05 2384.07 2384.09 2384.13 2384.48 2384.68 2384.84 2384.91 2384.98 2384.76 2384.98 2383.37 2384.32 2384.14 2384.14 2384.16 2384.20 2384.22 2384.26 2384.35 2384.40 2384.47 2384.52 2384.56 2384.61 2384.65 2384.70 2384.76 2384.81 2384.87 2384.95 2385.01 2385.18 2385.38 2385.49 2385.57 2385.64 2386.86 2387.81 2388.12 ___ ___ —— 2388.12 2384.14 2389.25 2390.74 2391.59 2391.90 2392.09 2392.23 2392.36 2392.46 2392.56 2392.77 2393.06 2393.43 2393.78 2394.12 2394.29 2394.42 2394.57 2394.69 2394.77 2394.86 2394.97 2395.07 2395.04 2395.09 2395.14 2395.21 2395.28 2395.34 2395.39 2395.47 2395.48 2395.48 2389.25 2395.55 2395.60 2395.55 2395.24 2394.82 2394.59 2394.27 2394.24 2394.29 2393.96 2393.53 2393.52 2393.24 2393.20 2393.21 2393.37 2393.64 2393.53 2393.32 2393.08 2392.88 2392.88 2392.92 2392.77 A A A A A A --- ___ MAY A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A AUG A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A SEP A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A 96 RIO GRANDE DE HANATI BASIN 50034000 RIO BADTA NEAR OROCOVIS, PR LOCATION.--Lat 18°14'10", long 66°27'18", Hydrologic Dnit 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 mi» (43.3 km 1 ). WATER-DISCHARGE RECORDS 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 gaye. Datum of gage is 772.82 ft (235.556 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 3.7 4.6 2 3.4 e38 3 3.1 e36 4 3.3 7.1 5 3.2 6.9 6 3.0 6.6 7 3.2 6.4 8 3.5 5.9 9 17 5.2 10 9.4 5.0 11 11 4.7 12 28 4.4 13 11 4.2 14 7.2 4.1 15 25 3.9 16 7.7 3.9 17 6.3 3.9 18 19 3.9 19 14 4.0 20 7.7 4.3 21 5.9 3.8 22 14 3.6 23 251 3.6 24 40 3.5 25 36 3.5 26 18 7.0 27 11 9.0 28 7.8 6.4 29 6.5 5.3 30 5.5 5.0 31 5.0 --- TOTAL 590.4 213.7 MEAN 19.0 7.12 MAX 251 38 MIN 3.0 3.5 AC-FT 1170 424 CFSM 1.14 .43 IN. 1.32 .48 4.9 4.7 12 7.5 5.7 4.9 4.4 4.2 4.0 3.8 3.7 3.6 3.6 3.5 3.6 3.5 3.5 3.7 3.6 3.4 3.4 3.3 3.4 3.5 3.7 3.9 3.9 4.6 4.1 3.7 3.7 133.0 4.29 12 3.3 264 .26 .30 STATISTICS OF MONTHLY MEAN DATA MEAN 88.4 53.9 MAX 392 205 (WY) 1971 1971 MIN 14.6 7.12 (WY) 1994 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 28.1 108 1971 4.29 1995 FOR 3.5 3.3 3.1 3.1 3.1 3.0 3.0 3.0 3.0 3.6 4.0 3.8 3.8 3.4 3.2 3.2 3.1 3.0 3.0 3.1 3.1 3.0 3.0 3.0 3.2 9.7 6.1 5.2 4.5 3.9 3.6 113.6 3.66 9.7 3.0 225 .22 .25 FOR WATER 19.7 83.4 1992 3.66 1995 3.4 3.3 3.2 3.0 3.0 3.0 3.0 3.1 3.3 3.3 3.4 3.4 3.2 3.2 3.1 3.2 3.3 3.4 3.6 3.7 6.7 10 5.1 4.0 3.8 29 43 14 ___ ___ ___ 180.7 6.45 43 3.0 358 .39 .40 YEARS 1969 13.4 30.9 1971 5.70 1994 15 21 9.5 7.0 5.8 5.0 4.4 4.2 3.9 13 20 22 30 35 20 11 8.2 6.7 5.8 5.4 5.1 .9 .8 .6 .3 .1 .1 .3 .2 .1 .1 301.5 9.73 35 3.9 598 .58 .67 - 1995 15.0 59.9 1972 4.18 1994 1994 CALENDAR YEAR 2216. 6. 251 2. 2. 4400 4. 8. 4. 3. 4 07 Oct 23 8 Jul 23 8 Jul 23 36 94 2 1 1 3.9 3.8 3.8 3.8 3.7 3.7 3.7 3.7 3.8 4.1 3.9 16 7.6 5.1 4.1 4.4 18 7.0 4.9 4.2 3.8 4.0 3.7 3.5 3.4 3.3 3.2 3.2 3.1 3.1 --- 147.5 4.92 18 3.1 293 .29 .33 3.1 3.2 11 13 27 38 318 561 633 256 97 58 41 61 157 105 49 31 24 145 105 47 29 23 30 42 248 160 81 85 85 3566.3 115 633 3.1 7070 6.89 7.94 49 35 29 24 21 19 18 17 16 15 15 15 14 13 13 12 12 11 11 11 11 10 10 9.7 9.7 9.7 54 48 16 12 ___ 560.1 18.7 54 9.7 1110 1.12 1.25 10 9.4 8.9 9.2 9.2 8.9 8.5 8.2 8.0 7.9 7.9 8.7 9.4 10 40 36 16 11 9.8 8.7 8.0 8.8 8.6 8.1 7.4 7.0 7.5 8.8 9.8 11 15 345.7 11.2 40 7.0 686 .67 .77 9.4 8.6 8.7 8.2 7.7 8.4 13 9.0 8. 1 7.7 7.3 7.2 9.1 8.6 7.3 7.2 7.7 15 34 22 16 12 10 10 9.4 8.7 8.3 46 64 21 15 434.6 14.0 64 7.2 862 .84 .97 12 11 11 9.8 18 288 233 399 100 55 39 33 26 23 71 850 365 194 106 118 115 79 e68 e62 646 e46 6360 e240 69 54 4122.8 137 850 9.8 8180 8.23 9.18 , BY WATER YEAR (WY) 26.5 80.2 1980 4.92 1995 FOR 1995 10709 29 850 3 3 2790 12 2 21240 1 23 54 7 3 51.9 179 1981 4.24 1994 WATER YEAR .9 .3 Sep 16 .0 Oct 6 .0 Jan 18 May 8 . 99 May 8 . 9 Jan 22 .76 .86 .7 .2 19.6 78.6 1979 3.59 1994 16.0 104 1979 3.22 1994 WATER 33 79 6 3870 2 2 17800 21 2 24560 2 27 63 13 5 20.9 152 1979 3.97 1994 YEARS 1969 9 .3 .56 Oct 8 Jul 8 Jul Oct 90 Oct 6 Jul .03 .58 .2 55.1 149 1979 3.55 1994 - 1995 1979 1994 9 1970 23 1994 23 1994 9 1970 9 1970 26 1994 e Estimated 97 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 Salients, 0.9 mi (1.4 km) upstream from Quebrada Cojo Vales, and 1.2 mi (1.9 km) southeast of Ciales. DRAINAGE AREA.--128 mi j (332 kmj ), excludes 6.0 mi 2 (15.5 kmj ), the runoff from which is diverted through El Guineo and de Matrullas reservoirs. WATER-DISCHARGE RECORDS 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 Rio Grande de Manati at Highway 145 at Ciales at site 1.6 mi (2.6 km) downstream, drainage area 132 mi 2 (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 satsllite telsmetry 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DEC JUL AUG 1 16 32 2 22 25 3 16 63 4 14 45 5 80 35 6 64 41 7 32 31 8 45 33 9 152 43 10 138 40 11 94 51 12 101 36 13 94 40 14 128 28 15 108 24 16 69 23 17 37 22 18 87 24 19 140 22 20 116 30 21 76 37 22 80 27 23 566 23 24 245 23 25 136 23 26 82 32 27 67 43 28 73 39 29 42 42 30 34 63 31 32 --- TOTAL 2986 1040 MEAN 96.3 34.7 MAX 566 63 MIN 14 22 AC-FT 5920 2060 CFSM .75 .27 IN. .87 .30 STATISTICS OF MONTHLY MEAN MEAN 431 343 MAX 2422 1006 (WY) 1971 1971 MIN 91.9 34.7 (WY) 1994 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 88 92 73 54 42 37 35 33 31 28 25 23 23 22 20 24 26 18 17 17 16 16 16 15 16 17 20 22 20 19 16 921 29.7 92 15 1830 .23 .27 DATA 259 1296 1966 29.7 1995 FOR 16 16 16 16 16 15 14 13 13 14 20 22 20 19 17 14 14 13 14 14 14 14 12 12 11 46 141 86 79 47 33 811 26.2 141 11 1610 .20 .24 FOR WATER 187 678 1952 26.2 1995 27 24 23 22 22 21 21 21 22 33 26 25 23 22 22 22 22 23 25 30 31 52 46 34 74 205 618 294 ___ ___ --- 1830 65.4 618 21 3630 .51 .53 YEARS 1946 168 1392 1950 41.6 1957 376 287 117 72 50 39 29 27 27 204 e335 e!40 e!50 e230 e230 e!30 e80 e62 e52 e46 e40 e36 e33 e31 e29 e28 e27 23 23 22 22 2997 96.7 376 22 5940 .76 .87 - 1995 139 477 1969 29.7 1994 1994 CALENDAR YEAR 13413. 36. 566 8. 9. 26610 3! 59 27 15 9 8 Oct 23 5 Jul 28 5 Jul 24 29 90 21 21 21 21 21 21 21 21 40 40 33 177 81 37 28 25 42 43 30 25 22 21 21 21 20 18 17 17 16 16 —— 958 31.9 177 16 1900 .25 .28 16 15 24 130 348 302 1100 2100 2890 1360 e400 e430 e460 e2000 e2200 e580 e310 e430 e640 e640 e!80 e200 176 144 114 324 671 634 383 389 372 19962 644 2890 15 39590 5.03 5.80 258 191 174 169 135 113 100 94 84 77 73 75 64 60 59 57 54 51 49 47 45 45 44 43 39 39 51 311 92 58 --- 2751 91.7 311 39 5460 .72 .80 49 42 41 46 45 43 41 39 37 33 34 36 36 75 92 137 69 52 48 45 44 53 56 47 45 41 42 56 97 69 119 1709 55.1 137 33 3390 .43 .50 72 54 54 56 48 44 58 48 43 40 38 38 36 47 58 50 42 47 164 96 69 51 48 60 67 52 46 44 278 100 97 2045 66.0 278 36 4060 .52 .59 60 83 119 141 82 1500 ioid 1600 493 272 187 185 149 120 200 6160 1540 861 490 482 462 325 333 425 283 226 419 586 315 246 —— 19354 645 6160 60 38390 5.04 5.62 , BY WATER YEAR (WY) 262 1174 1969 28.5 1984 FOR 1995 57364 157 6160 11 13 13700 8 11 113800 1 16 334 45 17 428 2293 1985 29.6 1994 WATER YEAR Sep 16 Jan 25 Jan 19 Sep 16 .98 Sep 16 Jan 24 .23 .67 155 458 1979 17.8 1994 106 438 1979 14.1 1994 WATER 244 520 47. 42700 8. 9. 125000 24 11 176500 1. 25. 443 113 51 151 1212 1979 27.0 1994 YEARS 1946 .3 May .5 Jul .5 Jul Oct .00 Oct Jan .90 .86 282 994 1979 23.9 1994 - 1995 1971 1994 18 1985 28 1994 24 1994 9 1970 9 1970 24 1995 e Estimated 98 RIO GRANDE DE MANATI BASIN 50035500 RIO GRANDE DB 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 Rio Cialitos, 0.5 mi (0.8 km) north of Ciales plaza. DRAINAGE AREA.--136 mi' (352 km1 ) this excludes the 6 mi 1 (15.5 km1 ) upstream from Lago El Guineo and Lago de Matrullas, flow from which is diverted to Rio Jacaguas. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 13. .. DEC 08... FEB 1995 10. . . APR 13... JUN 09. .. AUG 24. .. DATE OCT 1994 13. .. DEC 08. .. FBB 1995 10. .. APR 13. .. JUN 09. .. AUG 24. . . DATE OCT 1994 13. .. DEC 08. . . FEB 1995 10. .. APR 13. .. JUN 09. .. AUG 24... . TIME 0945 1130 1050 0830 0930 0810 HARD- NESS TOTAL (MG/L AS CAC03) 110 -- -- 100 __ 90 SILICA, DIS- SOLVED (MG/L AS SI02) 22 -- — 21 — 23 DIS- CHARGE, INST. CUBIC FEET PER SECOND 46 36 29 157 102 67 CALCIUM DIS- SOLVED (MG/L AS CA) 28 -- -- 28 __ 23 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 160 -- -- 148 — 143 SPE- CIFIC CON- DUCT- ANCE (US /CM) 265 290 284 245 255 243 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 10 -_ -- 7.7 __ 7.8 SOLIDS, DIS- SOLVED (TONS PER DAY) 20.1 -- — 62.9 — 26.0 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.4 8.1 7.9 7.6 8.2 7.2 SODIUM, DIS- SOLVED (MG/L AS NA) 13 __ __ 11 __ 11 RESIDUE TOTAL AT 105 DBG. C, SUS- PENDED (MG/L) 46 4 21 17 6 14 TEMPER- ATURE WATER (DBG C) 25.0 25.0 26.0 24.0 26.5 28.0 SODIUM AD- SORP- TION RATIO 0.5 — __ 0.5 __ 0.5 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.40 <0.20 <0.20 0.30 <0.20 0.63 TUR- BID- ITY (NTU) 39 8.9 20 23 1.0 9.3 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.9 __ _- 2.3 __ 1.6 PHOS- PHORUS TOTAL (MG/L AS P) 0.120 0.050 0.050 0.060 0.030 0.060 OXYGEN, DIS- SOLVED (MG/L) 7.8 8.8 8.1 7.4 8.6 5.0 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 85 110 110 92 100 92 ARSENIC TOTAL (UG/L AS AS) <1 -- — <1 — -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 92 104 99 88 107 64 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 __ -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 87 <10 31 10 <10 <10 SULFATE DIS- SOLVED (MG/L AS SO4) 17 -- — 9.1 __ 9.3 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 30 -- — 10 — -- COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 2700 K150 K1600 3800 K720 390 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 16 -- -- 14 -_ 12 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 380 240 K1200 3800 540 290 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 -- — 0.10 -- 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 — -- K = non-ideal count RIO GRANDE DE MANATI BASIN 50035500 RIO GRANDE DE MANATI AT HIGHWAY 149 AT CIALES, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 99 DATE OCT 1994 13. .. DEC 08. .. FEB 1995 10. .. APR 13. .. •TUN 09... ADG 24. .. COPPER, TOTAL RECOV- ERABLE (DG/L IRON, TOTAL RECOV- ERABLE (DG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (DG/L MERCURY TOTAL RECOV- ERABLE (DG/L SELE- NIUM, TOTAL (DG/L SILVER, TOTAL RECOV- ERABLE (DG/L ZINC, TOTAL RECOV- ERABLE (DG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLDE ACTIVE SUB- STANCE AS CD) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (DG/L) 20 1500 1200 80 80 <0.10 <0.10 <0.010 <0.010 (MG/L) 0.03 <0.02 100 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 mi 1 (44.0 km 1 )- PERIOD OP RECORD.--Water years 1969-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 13. .. DEC 08. . . FEB 1995 10. .. APR 13. .. JUN 09. .. AUG 24. .. DATE OCT 1994 13. .. DEC 08. .. FEB 1995 10. .. APR 13. .. JUN 09. .. AUG 24. .. TIME 1130 1240 0935 1015 1100 0945 HARD- NESS TOTAL (HG/L AS CAC03) 98 -- -- 88 -- 100 SILICA, DATE OCT 1994 13. .. DEC 08. .. FEB 1995 10... APR 13... JUN 09. .. AUG 24. . . K = non-ideal DIS- SOLVED (MG/L AS SI02) 25 -- -- 22 -- 28 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 4.4 4.9 3.6 15 22 14 CALCIUM DIS- SOLVED (HG/L AS CA) 28 __ -- 26 -- 28 SOLIDS , SOU OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 151 __ -- 133 __ 155 SPE- CIFIC CON- DUCT- ANCE (US/CM) 235 291 297 224 238 255 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 6.7 __ -- 5.7 -- 7.2 SOLIDS, DIS- SOLVED (TONS PER DAY) 1.80 __ -_ 5.49 __ 5.77 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.7 8.0 7.8 7.5 8.4 7.3 SODIUM, DIS- SOLVED (MG/L AS NA) 11 __ -- 9.5 -- 11 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 14 5 94 28 2 4 TEMPER- ATURE WATER (DEG C) 24.0 23.0 22.0 23.0 25.5 25.5 SODIUM AD- SORP- TION RATIO 0.5 __ — 0.4 -- 0.5 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.30 0.20 0.20 0.30 0.20 0.36 TUR- BID- ITY (NTU) 4.9 9.4 29 27 0.70 4.6 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.6 __ -- 2.3 -- 1.6 PHOS- PHORUS TOTAL (MG/L AS P.) 0.080 0.110 0.100 0.080 0.030 0.120 OXYGEN, DIS- SOLVED (MG/L) 7.9 8.1 6.7 7.8 8.6 5.3 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 90 120 130 79 98 100 ARSENIC TOTAL (UG/L AS AS) <1 __ __ 3 _ — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 92 92 89 91 105 64 SULFIDE TOTAL (MG/L AS S) <0.5 __ -- <0.5 -- -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 __ _- <100 __ -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 10 23 14 10 <10 <10 SULFATE DIS- SOLVED (MG/L AS SO4) 11 __ — 8.0 -- 7.0 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 20 __ -- <10 __ — COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) K880 24000 K8100 3500 520 2000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 13 __ -- 12 -- 12 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 __ __ <1 __ -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 520 320 K11000 3500 400 2100 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 __ -- <0.10 -- <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 _- -- <1 __ -- RIO GRANDE DE MANATI BASIN 50035950 RIO CIALITOS AT HIGHWAY 649 AT CIALES, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 101 DATE OCT 1994 13. .. DEC 08. .. FEB 1995 10. .. APR 13. .. JUN 09. .. AUG 24. .. COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 — -- <10 _- -- IRON, TOTAL RECOV- ERABLE (UG/L AS FE) 290 -- -- 700 __ -- LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) 1 — -- 5 __ — MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 40 -- -- 60 __ -- MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 — — <0.10 __ — SELE- NIUM, TOTAL (UG/L AS SE) <1 -- -_ <1 __ -- SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <1 — — <1 __ -- ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) <10 -- -- <10 __ -- CYANIDE TOTAL PHENOLS (MG/L TOTAL AS CN) (UG/L) <0.010 <1 __ __ <0.010 3 __ __ METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) 0.04 -- — <0.02 -- -- 102 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR LOCATION.--Lat 18°25'52 n , long 66°31'37", Hyarologic Unit 21010002, at bridge on Highway 2, and 2.3 mi (3.7 km) west of Manatf. DRAINAGE AREA.--197 mi 9 (510 km9 ), approximately, of which about 38 mi 1 (98 km9 ) is partly or entirely noncontributing, excludes 6.0 mi 9 (15.5 km9 ) upstream from Lago El Guineo and Lago de Matrullaa. WATER-DISCHARGE RECORDS PERIOD OP 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. 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 (10.45m). DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT DEC JAN FEB MAR APR MAY JUN AUG SEP 1 61 86 2 57 80 3 67 83 4 54 110 5 51 89 6 182 82 7 82 75 8 121 71 9 156 79 10 192 97 11 162 84 12 127 119 13 129 72 14 182 64 15 155 51 16 121 45 17 67 44 18 71 50 19 154 48 20 152 45 21 115 81 22 151 58 23 557 47 24 521 41 25 252 41 26 194 43 27 142 77 28 165 79 29 127 82 30 101 108 31 92 —— TOTAL 4760 2131 MEAN 154 71.0 MAX 557 119 MIN 51 41 AC-FT 9440 4230 CFSM .78 .36 IN. .90 .40 STATISTICS OF MONTHLY MEAN MEAN 750 546 MAX 2958 1803 (WY) 1971 1971 MIN 154 71.0 (WY) 1995 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 129 126 214 128 104 88 82 84 79 71 65 60 56 54 54 54 98 70 53 49 47 46 45 42 43 47 47 56 50 45 40 2226 71.8 214 40 4420 .36 .42 DATA 368 1498 1971 71.8 1995 FOR 40 38 39 39 37 36 36 34 34 36 37 44 43 41 42 37 34 32 33 37 34 33 33 31 35 77 230 199 167 136 107 1831 59.1 230 31 3630 .30 .35 90 84 79 79 79 79 80 83 86 107 108 88 78 70 64 61 59 56 57 60 58 59 84 75 123 371 731 533 ___ ___ --- 3581 128 731 56 7100 .65 .68 FOR WATER YEARS 1970 246 771 1992 59.1 1995 198 444 1988 72.0 1994 271 715 212 142 104 87 75 71 68 67 395 236 245 362 363 225 141 105 87 74 67 58 53 52 48 46 46 43 42 40 39 4579 148 715 39 9080 .75 .86 - 1995 188 521 1972 56.2 1994 1994 CALENDAR YEAR 28940 79.3 557 32 33 57400 .40 5.46 123 64 47 Oct 23 Jul 25 Jul 23 39 38 36 35 35 35 36 36 40 94 56 133 165 82 55 43 39 63 52 40 35 33 35 36 35 34 33 34 34 35 --- 1496 49.9 165 33 2970 .25 .28 37 35 34 52 385 275 682 2340 3860 4480 1250 803 577 702 3040 3550 941 625 461 953 948 410 278 321 191 341 975 1210 572 555 459 31342 1011 4480 34 62170 5.13 5.92 371 308 283 268 231 205 182 172 161 150 153 146 131 119 116 110 106 98 92 89 86 81 78 74 71 69 68 279 197 115 4609 154 371 68 9140 .78 .87 98 84 74 116 106 90 81 76 71 64 63 72 67 88 155 171 127 90 77 72 68 77 99 80 69 63 64 69 128 122 121 2802 90.4 171 63 5560 .46 .53 109 129 102 102 89 74 92 92 75 74 67 61 58 56 134 102 81 83 161 172 123 101 88 107 115 103 84 74 203 183 131 3225 104 203 56 6400 .53 .61 148 122 98 281 150 1620 1690 2330 771 430 312 272 239 194 174 14700 3320 1730 793 624 809 457 360 608 375 294 258 988 398 301 --- 34846 1162 14700 98 69120 5.90 6.58 , BY WATER YEAR (WY) 366 1037 1993 49.9 1995 FOR 1995 97428 267 14700 31 33 37900 31. 28 193200 1. 18. 460 84 38 693 3178 1985 93.7 1989 WATER YEAR Sep 16 Jan 24 Jan 18 Sep 16 42 Sep 16 Jan 23 35 40 240 747 1987 63.8 1994 158 577 1979 53.0 1994 WATER 366 756 96 55900 31 33 97200 33 28 265500 1 25 648 166 85 216 1644 1979 67.9 1984 YEARS 1970 - .5 May 18 Jan 24 Jul 23 Oct 7 .79 Oct 7 .0 Jan 23 .86 .28 449 1510 1979 67.4 1994 1995 1971 1994 1985 1995 1994 1985 1985 1995 RZO GRANDE DE MANATI BASZN 50038100 RZO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATZ, PR—Continued (National stream-quality accounting network station) WATER-QUALITY RECORDS PERZOD OP RECORD.--Hater years 1969 to current year. WATER-QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 103 DZS- PH OXYGEN, COLZ- CHAROE, SPE- HATER DZS- FORM, STREP- HARD- ZNST. CZFZC WHOLE SOLVED FECAL, TOCOCCZ NESS CALCIUM CDBZC CON- FZELD TEMPER- TOR- OXYGEN, (PER- 0.45 FECAL, TOTAL DZS- FEET DUCT- (STAND- ATDRE BZD- DZS- CENT UM-MF (COLS. (MG/L SOLVED DATE TZME PER ANCE ARD HATER ZTY SOLVED SATDR- (COLS./ PER AS (MG/L SECOND (US /CM) UNITS) (DBG C) (NTU) (MG/L) ATZON) 100 ML) 100 ML) CACO3) AS CA) OCT 1994 21. DEC 12. 1115 117 1405 62 307 326 7.7 7.9 27.0 27.0 2.9 2.9 5.3 9.0 65 111 2000 K1700 9400 490 140 40 150 48 FEB 1995 22. APR 27. JUN 26. AUO 28. OCT 21 DEC 12 FEB 22 APR 27 JUN 26 AUO 28 OCT 21 DEC 12 FEB 22 APR 27 JUN 26 AUO 28 K = 1300 1315 1130 0825 MAGNE- SIUM, DIS- SOLVED DATE (MG/L AS MG) 1994 8.5 8.3 1995 8.0 8.2 8.6 8.1 SOLZDS, DIS- SOLVED (TONS DATE PER DAY) 1994 60.7 35.0 1995 33.3 19.1 36.9 39.3 non-ideal count 59 36 71 77 SODIUM, DIS- SOLVED (MG/L AS NA) 12 11 12 10 12 11 NZTRO- GEN, NO2+NO3 DIS- SOLVED (MG/L AS N) 0.820 0.660 0.430 0.130 0.290 0.510 340 300 315 318 SODIUM AD- SORP- TION RATIO 0.4 0.4 0.4 0.4 0.4 0.4 NZTRO- OEN, AMMONIA DZS- SOLVED (MG/L AS N) 0.020 0.030 <0.015 0.020 0.040 0.030 7.8 7.7 8.0 7.4 POT AS - SZUM, DZS- SOLVED (MG/L AS K) 2.3 1.7 1.6 1.9 2.0 2.1 NZTRO- GEN, AMMONIA DZS- SOLVED (MG/L AS NH4) 0.03 0.04 -- 0.03 0.05 0.04 26.5 29.5 30.0 28.5 ALKA- LINITY HAT WH TOT FET FZELD MG/L AS CAC03 120 150 * 150 130 130 140 NZTRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.40 0.20 <0.20 0.30 0.30 0.20 0.90 1.3 7.7 12 SULFATE DZS- SOLVED (MG/L AS S04) 13 11 7.4 8.3 9.4 8.9 PHOS- PHORUS TOTAL (MG/L AS P) 0.090 0.070 0.040 0.060 0.050 0.030 10.2 9.4 8.8 2.2 CHLO- RZDE, DZS- SOLVED (MG/L AS CL) 16 16 15 12 14 13 PHOS- PHORUS DZS- SOLVED (MG/L AS P) 0.080 -- 0.030 0.020 0.030 -- 126 123 116 28 FLUO- RZDE, DZS- 590 K1200 43000 40000 SZLZCA, DIS- SOLVED SOLVED (MG/L (MG/L AS F) 0.10 <0.10 <0.10 <0.10 0.10 0.10 PHOS- PHORUS ORTHO, DZS- SOLVED (MG/L AS P) 0.070 0.080 0.030 0.030 0.040 0.050 AS SZO2) 20 17 13 19 15 12 PHOS- PHATE, ORTHO, DZS- SOLVED (MG/L AS P04) 0.21 0.25 0.09 0.09 0.07 0.12 210 K200 30000 31000 SOLZDS, RESIDUE AT 180 DEG. C DZS- SOLVED (MG/L) 192 210 211 204 193 188 ALUM- INUM, DIS- SOLVED (UG/L AS AL) 30 -- <10 -- 20 -- 170 54 130 40 140 43 110 38 SOLZDS, SUM OF CONST Z- TUENTS, DZS- SOLVED (MG/L) 188 206 203 196 182 189 BARIUM, DZS- SOLVED (UG/L AS BA) 48 -- 44 -- 52 -- 104 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR—Continued (National stream-quality accounting network station) WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 21. .. DEC 12. .. FEB 1995 22. . . APR 27. .. JUN 26. .. AUG 28. . . COBALT, DIS- SOLVED (UG/L AS CO) <3 — <3 -- <3 -- IRON, DIS- SOLVED (UG/L AS FE) 23 -- 22 -- 16 -- LITHIUM DIS- SOLVED (UG/L AS LI) <4 — <4 -- 4 — MANGA- NESE, DIS- SOLVED (UG/L AS MN) 19 -- 15 __ 50 -_ MERCURY DIS- SOLVED (UG/L AS HG) <0.1 __ 0.2 __ <0.1 __ MOLYB- DENUM, DIS- SOLVED (UG/L AS MO) 10 -- <10 __ <10 __ SELE- NICKEL, NIUM, SILVER, DIS- DIS- DIS- SOLVED SOLVED SOLVED (UG/L (UG/L (UG/L AS NI) AS SE) AS AG) <1 <1 <1.0 — <1 <1 <1.0 __ <1 <1 <1.0 __ STRON- TIUM, DIS- SOLVED (UG/L AS SR) 200 -- 260 -- 240 -- VANA- DIUM, DIS- SOLVED (UG/L AS V) <6 -- 7 __ 8 -- PESTICIDE ANALYSES CHLOR- DANE, P,P'- P,P'- ENDO- TECH- ODD DOT DI- DI- SULFAN, PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I DATE TIME 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) JUN 1995 26... 1130 <0.100 <0. ENDRIN WATER UNFLTRD ETHION, DATE REC TOTAL (UG/L) (UG/L) JUN 1995 26... <0.010 <0.010 PARA- PCNS THION, UNFILT DATE TOTAL RECOVER (UG/L) (UG/L) JUN 1995 26... <0.010 <0.100 010 <0 HEPTA- CHLOR, TOTAL (UG/L) <0.010 PER- THANE TOTAL (UG/L) <0.100 .100 <0. HEPTA- CHLOR EPOXIDE TOTAL (UG/L) <0.010 TOX- APHENE, TOTAL (UG/L) <1.00 PARTICLE -SIZE DISTRIBUTION DATE OCT 1994 21.. . DEC 12.. . FEB 1994 22.. . APR 27.. . JUN 26.. . AUG 28.. . TIME 1115 1405 1300 1315 1130 0825 STREAM- FLOW, INSTAN- TANEOUS (CFS) 117 62 59 36 71 77 010 <0 LINDANE TOTAL (UG/L) <0.010 TOTAL TRI- THION (UG/L) <0.010 .010 <0. MALA- THION, TOTAL (UG/L) <0.010 2,4-D, TOTAL (UG/L) 0.010 .010 <0.010 <0.010 <0.010 METH- METHYL OXY- PARA- CHLOR, THION, MIREX, TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) <0.010 <0.010 <0.010 2,4,5-T 2, 4-DP SILVEX, TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) <0.010 <0.010 <0.010 OF SUSPENDED SEDIMENT SEDI- MENT, SUS- PENDED (MG/L) 23 23 41 25 19 23 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 7.3 3.8 6.5 2.4 3.6 4.8 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 99 98 54 58 86 92 105 LACUNA TORTUGUERO BASIN 50038200 LACUNA 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 Manatl, 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 1994 TO SEPTEMBER 1995 DATE TIME PH WATER WHOLE FIELD TEMPER- (STAND- ATURE ARD WATER UNITS) (DEG C) 100 ML) 100 ML) CACO3 OCT 1994 14... DEC 07... FEB 1995 10... APR 12... JUN 12... AUG 31... 1000 1100 1215 0845 1145 0755 8.3 12 0.0 3.3 0.0 4.3 1600 1440 1200 1490 1400 1150 7.8 7.7 7.9 7.5 8.2 7.4 29.0 27.0 27.0 28.5 30.0 31.0 6.1 5.0 6.2 3.9 4.8 4.0 78 62 77 50 64 53 38 32 37 38 46 44 120 K10 K10 K110 160 340 100 K40 K30 300 K51 K130 120 110 110 110 85 100 COLI- ALKA- FORM, STREP- LINITY FECAL, TOCOCCI WAT WH 0.45 FECAL, TOT FET SULFIDE UM-MF (COLS. FIELD TOTAL (COLS./ PER MG/L AS (MG/L AS S) <0.5 <0.5 RESIDUE NITRO- BORON, COPPER, IRON, MANGA- NESE, ZINC, METHY- LENE DATE OCT 1994 14. .. DEC 07. .. PEB 1995 10... APR 12. .. JUN 12. .. AUG 31. .. AT 105 DEG. C, SUS- PENDED (MG/L) 4 6 <1 6 4 7 MONIA + ORGANIC TOTAL (MG/L AS 1 1 1 1 1 1 N) .4 .0 .3 .3 .2 .5 PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL PHORUS RECOV- RECOV- RECOV- RECOV- RECOV- CYANIDE TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL PHENOLS (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL AS 0. 0. 0. <0. 0. 0. P) AS B) AS CU) AS FE) AS MN) AS ZN) AS CN) (UG/L) 010 90 <10 40 <10 <10 <0.010 <1 010 030 010 90 <10 90 10 <10 <0.010 <1 020 010 BLUE ACTIVE SUB- STANCE (MG/L) 0.06 — -- <0.02 -- — non-ideal count 106 THIS PAGE WAS LEFT BLANK INTENTIONALLY ATLANTIC 107 EXPLANATION 038320 SURFACE-WATER STATION AND NUMBER 0397 QUALITY-OF-WATER STATION AND NUMBER 213 WELL AND WELL NUMBER -Mop or to »**s» ,** JL. Figure 17.--Rio Cibuco basin. 108 RIO CIBUCO BASIN 50036320 RIO CIBUCO BELOW COROZAL, PR LOCATION.--Lat 18°21'13", long 66°20'07", Hydrologic Unit 21010001, on right bank, 150 ft (46 m) downstream from junction with Rio Corozal, and 1.4 mi (2.3 km) northwest of Corozal. DRAINAGE AREA.--15.1 mi a (39.1 km2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--Hay 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES MAR APR SEP 1 1.9 14 2 1.7 12 3 1.8 10 4 2.3 11 5 3.2 14 6 3.6 15 7 49 12 6 24 21 9 6.6 36 10 33 25 11 24 17 12 11 15 13 41 13 14 29 12 15 14 12 16 7.7 11 17 7.6 9.5 16 25 8.9 19 24 9.3 20 26 10 21 16 8.4 22 35 9.0 23 65 9.5 24 34 8.3 25 22 10 26 18 9.0 27 17 12 28 15 13 29 15 27 30 13 18 31 14 —— 9.8 7.6 6.9 6.9 5.5 6.7 6.8 7.0 7.3 5.6 4.3 4.4 4.4 3.7 3.4 3.0 2.5 2.6 2.3 2.2 2.0 2.0 2.4 1.8 1.7 1.7 3.6 2.8 2.6 2.3 2.4 TOTAL 600.4 413.9 128.2 MEAN 19.4 13.8 MAX 65 38 MIN 1.7 8.3 AC-FT 1190 821 CFSM 1.28 .91 IN. 1.48 1.02 STATISTICS OF MONTHLY MEAN MEAN 40.3 43.8 MAX 135 155 (WY) 1991 1971 MIN 8.05 8.15 (WY) 1979 1974 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 4.14 9.8 1.7 254 .27 .32 DATA 34.9 169 1971 4.14 1995 3.6 2.6 2.9 2.6 2.2 1.9 2.1 2.2 2.3 4.8 5.0 4.8 4.5 3.4 2.7 2.5 2.2 1.9 2.7 5.2 3.8 2.5 2.6 2.4 4.4 61 22 27 13 7.9 6.2 214.9 6.93 61 1.9 426 .46 .53 FOR WATER 23.8 69.6 1992 6.93 1995 5.1 4.4 3.9 3.3 3.7 3.7 3.6 4.0 4.7 3.6 3.8 3.5 3.1 3.7 3.6 3.7 4.4 4.5 5.9 8.5 7.6 6.9 5.5 5.3 46 59 119 82 ___ --- 416.0 14.9 119 3.1 825 .98 1.02 YEARS 1969 20.8 51.3 1988 7.75 1994 27 15 10 9.7 8.0 7.3 9.4 8.8 6.9 13 10 7.9 17 56 22 13 8.7 8.1 6.7 6.5 6.3 5.6 4.8 4.2 3.7 2.9 3.6 3.6 2.7 2.6 2.0 313.0 10.1 56 2.0 621 .67 .77 - 1995 21.9 65.1 1981 4.36 1984 FOR 1994 CALENDAR YEAR 2559. 7. 65 . 1. 5080 6. 15 5. 1. 91 01 Oct 23 91 Jul 17 2 Jun 21 46 31 2 7 2.1 1.8 1.5 1.6 1.5 2.1 1.9 1.3 89 14 4.2 34 9.2 4.8 3.8 2.1 9.1 3.8 3.1 2.1 2.0 2.8 2.1 1.5 1.3 1.4 1.2 1.0 .96 1.1 --- 208.36 6.95 89 .96 413 .46 .51 2.1 1.7 2.9 103 51 31 146 281 62 22 12 7.7 27 62 228 181 166 93 63 57 36 e23 18 16 15 13 13 12 31 27 17 1820.4 58.7 281 1.7 3610 3.89 4.48 12 14 17 12 9.7 9.4 8.5 7.8 57 18 12 10 8.9 7.5 7.4 11 7.7 6.3 5.8 6.4 6.7 6.3 5.5 4.5 4.7 5.0 11 20 8.8 5.8 --- 326.7 10.9 57 4.5 648 .72 .80 7.3 6.2 6.4 16 12 9.6 11 9.7 8.5 8.0 14 11 11 22 8.4 6.1 5.9 5.4 8.2 15 13 17 11 7.5 8.2 14 21 32 27 9.6 10 372.0 12.0 32 5.4 738 .79 .92 6.8 23 75 15 9.1 7.5 6.8 6.1 5.8 6.6 5.1 5.2 4.3 4.4 5.0 20 21 12 10 7.2 6.1 6.1 43 35 21 16 11 8.5 9.8 e33 116 561.4 18.1 116 4.3 1110 1.20 1.38 156 36 e76 e31 39 409 145 100 40 29 21 18 16 14 42 493 76 38 28 23 22 19 19 16 16 14 75 31 19 17 --- 2078 69.3 493 14 4120 4.59 5.12 , BY WATER YEAR (WY) 34.2 111 1973 3.32 1984 FOR 1995 7453 20 493 1 2950 11 14780 1 18 39 8 2 46.3 157 1986 3.20 1977 WATER YEAR .26 .4 Sep 16 .96 Apr 29 .2 Apr 24 May 8 .41 May 8 .35 .36 .8 .2 14.8 44.4 1987 1.63 1994 12.2 34.6 1979 2.19 1994 WATER 28 56 7 2370 1 13600 19 20450 1 25 49 13 5 16.7 50.8 1979 3.44 1978 YEARS 1969 - .2 .5 .47 May 18 .91 Jul 17 .2 Jun 21 Nov 7 .80 Nov 7 .87 .40 .3 27.6 73.2 1979 3.88 1994 1995 1971 1994 1985 1994 1994 1979 1979 e Estimated 109 RIO CIBDCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR--Continued WATER-QUALITY RECORDS PERIOD OP RECORD.--Water years 1969-76, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 WATER-QUALITY DATA DATE OCT 1994 17. .. DEC 14. .. FEB 1995 08. .. APR 17. .. JUN 13. .. AUG 31. .. DATE OCT 1994 17. .. DEC 14. .. FEB 1995 08. .. APR 17. .. JUN 13. .. AUG 31. .. DATE OCT 1994 17. .. DEC 14. .. FEB 1995 08. .. APR 17. .. JUN 13... AUG 31. .. TIME 1315 1200 0935 1100 1200 1105 HARD- NESS TOTAL (MG/L AS CACO3) 180 -- -- 150 -- 130 SILICA, DIS- SOLVED (MG/L AS SIO2) 28 — -- 28 -- 26 DIS- CHARGE, INST. CUBIC FEET PER SECOND 7.9 3.8 4.7 13 11 11 CALCIUM DIS- SOLVED (MG/L AS CA) 49 -- -- 38 __ 33 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 284 -- -- 225 -- 193 SPE- CIFIC CON- DUCT- ANCE (US/CM) 465 464 472 370 400 370 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 14 -- -- 13 __ 11 SOLIDS, DIS- SOLVED (TONS PER DAY) 6.09 _- -- 7.96 -- 5.67 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.8 7.8 7.7 7.8 8.1 7.2 SODIUM, DIS- SOLVED (MG/L AS NA) 26 -- -- 19 _- 18 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 4 <1 1 <1 4 20 TEMPER- ATURE WATER (DEG C) 25.0 24.0 22.0 25.0 28.0 27.0 SODIUM AD- SORP- TION RATIO 0.8 — _- 0.7 __ 0.7 NITRO- GEN, AM- MONIA +• ORGANIC TOTAL (MG/L AS N) 0.40 0.50 1.6 0.30 0.31 0.65 TUR- BID- ITY (NTU) 3.7 2.3 1.0 2.7 1.3 29 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 5.0 -- -- 3.9 __ 4.6 PHOS- PHORUS TOTAL (MG/L AS P) 0.620 0.780 0.610 0.830 0.300 0.310 OXYGEN, DIS- SOLVED (MG/L) 6.5 8.0 6.9 7.7 7.4 5.5 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CACO3 130 150 170 130 140 100 ARSENIC TOTAL (UG/L AS AS) 1 __ -- 1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 78 94 78 94 95 69 SULFIDE TOTAL (MG/L AS S) <0.5 -_ -_ <0.5 __ ~~ BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -_ -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 13 <10 23 <10 12 21 SULFATE DIS- SOLVED (MG/L AS S04) 43 -- -- 18 — 15 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 40 -- -- 30 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 5100 K110 51000 K7900 4900 4000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 41 -- -- 27 __ 25 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS . PER 100 ML) 3700 K100 20000 7000 730 7100 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 — -- 0.10 __ <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- — <1 -- -- K = non- ideal count 110 RIO CIBTJCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE COPPER, TOTAL RECOV- ERABLE (UO/L IRON, TOTAL . RECOV- ERABLE (UO/L LEAD, TOTAL RECOV- ERABLE (UO/L MANGA- NESE, TOTAL RECOV- ERABLE (UO/L MERCURY TOTAL RECOV- ERABLE (UQ/L SELE- NIUM, TOTAL (UO/L SILVER, TOTAL RECOV- ERABLE (UO/L ZINC, TOTAL RECOV- ERABLE (UO/L CYANIDE TOTAL (MO/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS FE) AS PB) AS MN) AS HO) AS SB) AS AO) AS ZN) AS CN) (U6/L) OCT 1994 17. .. DEC 14. .. FEB 1995 08. .. APR 17. .. JUN 13. .. AUO 31. .. 250 190 40 40 <0.10 <0.10 <0.010 <0.010 (MO/L) 0.05 0.03 RIO CIBDCO BASIN 50039500 RIO CIBDCO AT VEGA BAJA, PR LOCATION.--Lat 18°26'53", long 66°22'29", Hydrologie Unit 21010002, on left bank, at bridge on Hwy 2, 0.6 mi (1.0 km) downstream from Rio Indio, and 0.8 mi (1.3 km) east of Vega Baja. DRAINAGE AREA.--99.1 mi 1 (256.7 km1 ), of which 25.4 mi 1 (65.8 km1 ), 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 (2.374 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 ft*/s (793 m'/s). DISCHARGE, CUBIC FEET PER SECOND, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 111 DEC FEB MAR ADG SEP 1 15 31 2 14 28 3 13 25 4 12 24 5 12 28 6 12 30 7 13 27 8 175 44 9 34 140 10 71 196 11 139 117 12 83 167 13 29 71 14 119 42 15 177 34 16 37 30 17 21 27 18 56 25 19 119 23 20 167 22 21 51 23 22 144 23 23 206 22 24 188 20 25 93 20 26 61 23 27 45 23 28 38 25 29 34 43 30 31 126 31 29 —— TOTAL 2238 1479 MEAN 72.2 49.3 MAX 206 196 MIN 12 20 AC-FT 4440 2930 CFSM .73 .50 IN. .84 .56 STATISTICS OF MONTHLY MEAN MEAN 156 179 MAX 559 523 (WY) 1986 1980 MIN 45.9 40.0 (WY) 1974 1974 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 70 47 37 36 36 35 35 37 34 30 25 22 21 21 19 18 17 17 17 16 16 15 15 14 14 14 15 32 20 17 16 778 25.1 70 14 1540 .25 .29 DATA 172 1316 1982 25.1 1995 FOR 16 17 15 16 15 15 14 13 15 17 24 23 22 20 17 15 15 14 14 15 22 16 14 14 13 49 181 120 105 42 29 937 30.2 181 13 1860 .31 .35 FOR WATER 90.9 209 1988 30.2 1995 24 21 19 18 18 16 16 18 19 27 21 19 17 16 16 17 19 21 21 28 28 33 27 21 19 118 536 401 ___ --- 1574 56.2 536 16 3120 .57 .59 YEARS 1973 86.5 190 1988 27.2 1994 173 69 46 37 33 29 28 31 28 26 38 28 43 143 114 51 36 30 27 24 22 21 19 20 21 19 19 20 19 18 17 1249 40.3 173 17 2480 .41 .47 - 1995 85.4 339 1990 20.5 1994 1994 CALENDAR YEAR 12008. 32. 319 8. 8. 23820 . 4. 60 22 12 2 9 May 17 1 Jul 25 7 Jul 23 33 51 16 15 15 15 14 14 13 12 14 151 22 89 54 23 19 15 86 25 16 14 12 12 12 11 10 9.3 9.2 9.1 8.7 8.6 ___ 743.9 24.8 151 8.6 1480 .25 .28 7.9 7.5 7.2 7.6 245 44 114 490 438 83 43 107 65 227 325 654 355 573 309 414 241 122 83 65 57 58 59 52 48 111 74 5486.2 177 654 7.2 10880 1.79 2.06 52 66 92 59 45 49 39 34 34 98 35 32 31 29 28 31 38 28 24 23 26 28 26 24 21 21 22 48 44 21 --- 1148 38.3 98 21 2280 .39 .43 20 17 15 18 32 24 21 17 15 13 12 21 19 17 81 22 16 14 14 15 74 82 58 23 21 17 43 52 124 38 32 987 31.8 124 12 1960 .32 .37 23 17 202 78 27 19 15 13 11 12 12 11 10 9.1 50 146 114 59 36 31 19 18 29 282 251 63 37 e28 22 20 e97 1761.1 56.8 282 9.1 3490 .57 .66 e320 e410 elOO e200 e90 ellO elOOO 329 123 59 121 101 37 27 39 1810 685 253 127 79 63 56 50 44 36 32 44 141 52 33 6571 219 1810 27 13030 2.21 2.47 , BY WATER YEAR (WY) 159 667 1987 16.2 1984 FOR 1995 24952 68 1810 7 8 2790 14 7 49490 9 143 28 14 202 655 1985 24.7 1977 WATER YEAR .2 .4 Sep 16 .2 May 3 .1 Apr 28 Sep 16 .89 Sep 16 .2 May 2 .69 .37 73.3 239 1987 12.5 1994 53.0 162 1979 14.0 1994 WATER 120 236 38 14600 7 8 34000 19 7 86790 1 16 223 58 22 80.6 461 1979 21.2 1978 YEARS 1973 .5 Dec .2 May .1 Apr Apr .10 Apr .2 May .21 .42 121 450 1979 26.7 1994 - 1995 1982 1994 13 1981 3 1995 28 1995 12 1987 12 1987 2 1995 112 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR--Continued WATER-QUALITY RECORDS PERIOD OP RECORD.—Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 14. .. DEC 07... PEB 1995 08. .. APR 12. .. JUN 12. .. SEP 08. .. DATE OCT 1994 14... DEC 07. .. FEB 1995 08... APR 12. .. JUN 12. .. SEP 08. .. DATE OCT 1994 14. .. DEC 07... FEB 1995 08. .. APR 12. .. JDN 12. .. SEP 08... TIME 1240 1340 1230 1145 1425 0930 HARD- NESS TOTAL (MO/L AS CAC03 ) 140 — -- 180 — 140 SILICA, DIS- SOLVED (MO/L AS SIO2) IS -- -- 15 -- 17 DIS- CHARGE, INST. CUBIC FEET PER SECOND US 35 19 82 31 338 CALCIUM DIS- SOLVED (MG/L AS CA> 41 -- -- 57 -- 43 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 198 -- -- 245 -- 191 SPE- CIFIC CON- DUCT- ANCE (US /CM) 360 434 469 417 423 340 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 8.1 -- -- 9.2 -- 7.6 SOLIDS, DIS- SOLVED (TONS PER DAY) 62.1 -- -- 54.2 -- 174 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.4 7.8 7.8 7.7 7.8 7.2 SODIUM, DIS- SOLVED (MG/L AS NA) 15 __ -- 18 -_ 12 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 74 3 <1 5 16 180 TEMPER- ATURE WATER (DEG C) 25.0 24.5 24.0 26.5 29.0 26.0 SODIUM AD- SORP- TION RATIO 0.6 __ -- 0.6 __ 0.4 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.60 0.20 <0.20 0.30 0.31 1.10 TUR- BID- ITY (NTU) 72 4.4 1.0 5.2 6.2 140 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 5.2 __ -- 4.3 -- 4.2 PHOS- PHORUS TOTAL (MG/L AS P) 0.290 0.210 0.250 0.180 0.210 0.140 OXYGEN, DIS- SOLVED (MG/L) 4.0 6.6 5.6 5.9 5.9 4.8 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CAC03 110 ISO 190 160 170 120 ARSENIC TOTAL (UG/L AS AS) <1 -- — <1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 47 78 66 74 77 59 SULPIDE TOTAL (MG/L AS S) <0.5 __ -- <0.5 -- -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 31 11 24 17 <10 31 SULFATE DIS- SOLVED (MG/L AS SO4) 25 _- -- 18 -- 18 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 30 -- -- 30 -- -- COLI- FORM, FECAL, 0.45 UM-MP (COLS./ 100 ML) K13000 520 310 K680 K990 K8000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 22 -- -- 27 -- 17 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- — STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 8800 330 310 K1700 390 22000 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 -- — 0.10 -- 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 4 -- -- <1 -- -- RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, P.R. WATER-QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 113 DATE OCT 1994 14. .. DEC 07. .. FEB 1995 oe. .. APR 12. .. JUN 12. .. SEP oe. .. COPPER, TOTAL RECOV- ERABLE (OG/L AS CO) <10 -- -- 10 -- -- IRON, TOTAL RECOV- ERABLE (OG/L AS FE) 2400 __ -- 240 __ -- LEAD, TOTAL RECOV- ERABLE (OG/L AS PB) 1 __ -- <1 __ — MANGA- NESE, TOTAL RECOV- ERABLE (OG/L AS MH) eo __ -_ 30 __ -- MERCURY TOTAL RECOV- ERABLE (OG/L AS HG) <0.10 — — <0.10 __ -- SELE- NIUM, TOTAL (OG/L AS SB) <1 __ -- <1 __ -- SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <1 — — <1 __ -- ZINC, TOTAL RECOV- ERABLE (OG/L AS ZN) 20 -- -- <10 __ -- CYANIDE TOTAL PHENOLS (MG/L TOTAL AS CN) (OG/L) <0.010 <1 __ — <0.010 14 __ __ METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) 0.04 -- -- 0.03 -- -- 114 THIS PAGE WAS LEFT BLANK INTENTIONALLY Drainage bounaones .ndeft-m nat« 045010 044950. „„... ^ t k \M / v_^ ma* ''?»i^ue,! r.csir >. ».'c 3siO»«s 'X» / bf...n '^; A 0460 SURFACE-WATER STATION AND NUMBER V 0430 QUALITY-OF-WATER STATION AND NUMBER 0399 1—7 QUALITY-OF-WATER PARTIAL V 216 RECORD STATION AND NUMBER A 0438 DAILY SEDIMENT STATION AND -^ NUMBER • 039990 WELL AND WELL NUMBER M0450 LAKE-ELEVATION STATION AND ™ NUMBER 115 Figure 18.--Rio de la Plata basin, 116 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 mi* (21.24 km9 ). ELEVATION RECORDS PERIOD OF RECORD.—Hay 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 1,787.61 ft (544.86 m), Jan. 5, 1992; minimum elevation, 1,761.22 ft (536.81 m), May 28, 1995. EXTREMES FOR CURRENT YEAR.—Maximum elevation 1,781.40 ft (543.00 m), Sept. 30; minimum elevation, 1,761.22 ft (536.81 m). May 28. Capacity Table (based on Data from Puerto Rico Electric Power Authority) Contents, in acre-feet Elevation, in feet Elevation, in feet 1,746 0 1,760 2,471 1,769 4,561 1,775 1,780 1,790 Contents, in acre-feet 6,194 7,704 11,048 DAY ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES OCT NOV DEC JAN FEB MAR APR JUN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX KEN 1770.32 1770.28 1770.21 1770.16 1770.09 1770.03 1769.99 1769.95 1769.90 1769.88 1769.83 1769.76 1769.70 1769.64 1769.58 1769.52 1769.49 1769.96 1769.96 1769.95 1769.96 1771.58 1772.87 1773.36 1773.53 1773.59 1773.63 1773.65 1773.65 1773.67 1773.68 1773.68 1769.49 1773.70 1773.70 1773.69 1773.70 1773.72 1773.92 1773.98 1774.05 1774.09 1774.32 1774.38 1774.41 1774.44 1774.45 1774.46 1774.47 1774.47 1774.46 1774.44 1774.42 1774.41 1774.41 1774.40 1774.37 1774.36 1774.39 1774.38 1774.36 1774.36 1774.39 1774.47 1773.69 1774.46 1774.56 1774.59 1774.59 1774.59 1774.58 1774.57 1774.53 1774.51 1774.48 1774.49 1774.47 1774.44 1774.37 1774.33 1774.30 1774.23 1774.14 1774.11 1774.04 1773.99 1773.93 1773.90 1773.83 1773.82 1773.75 1773.73 1773.67 1773.59 1773.53 1773.39 1774.59 1773.39 1773.29 1773.17 1773.09 1772.97 1772.88 1772.80 1772.71 1772.62 1772.53 1772.45 1772.32 1772.27 1772.14 1772.03 1771.92 1771.80 1771.66 1771.56 1771.46 1771.34 1771.21 1771.12 1770.97 1770.90 1770.76 1770.84 1770.70 1770.58 1770.47 1770.35 1770.21 1773.29 1770.21 1770.10 1769.97 1769.90 1769.74 A 1769.52 1769.52 1769.47 1769.39 1769.34 1769.27 1769.16 1769.10 1769.01 1768.95 1768.89 1768.87 1768.89 1768.88 1768.93 1769.35 1769.38 1769.38 1769.38 1770.22 1770.41 1770.46 1770.55 ___ --- _ _ —— 1770.52 1770.51 1770.52 1770.53 1770.53 1770.59 1770.58 1770.58 1770.67 1770.71 1770.81 1770.85 1770.90 1770.92 1770.88 1770.84 1770.83 1770.81 1770.79 1770.65 1770.51 1770.45 1770.33 1770.29 1770.14 1769.98 1769.89 1769.69 1769.61 1769.48 1769.33 1770.92 1769.33 1769.14 1769.00 1768.82 1768.73 1768.60 1768.39 1768.36 1768.10 1767.94 1767.85 1767.63 1767.66 1767.52 1767.39 1767.38 1767.10 1766.95 1766.78 1766.61 1766.32 1766.25 1766.11 1765.93 1765.88 1765.65 1765.58 1765.45 1765.24 1765.00 1764.94 —— 1769.14 1764.94 1764.68 1764.46 1764.33 1764.19 1764.08 1763.81 1763.77 1763.62 A A A A A A A A A 1762.13 1762.05 1762.01 1761.91 1761.75 1761.64 1761.50 1761.42 1761.38 1761.33 1761.26 1761.36 1761.40 1761.51 ___ 1761.65 1762.45 1762.84 1762.95 1762.99 1763.05 1763.17 1763.20 1763.22 1763.29 1763.37 1763.39 1763.41 1763.46 1763.62 1763.65 1763.63 1763.58 1763.53 1763.53 1763.51 1763.47 1763.44 1763.40 1763.37 1763.33 1763.39 1763.37 1763.33 1763.30 1763.65 1761.65 1763.27 1763.24 1763.25 1763.30 1763.34 1763.36 1763.36 1763.36 1763.37 1763.36 1763.37 1763.39 1763.44 1763.45 1763.59- 1763.66 1763.65 1763.72 1763.68 1763.66 1764.04 1764.13 1764.12 1764.12 1764.09 1764.06 1764.49 1764.60 1764.65 1764.89 1764.96 1764.96 1763.24 1764.96 1765.00 1765.11 1765.18 1765.23 1765.27 1765.31 1765.38 1765.42 1765.45 1765.47 1765.50 1765.50 1765.44 1765.38 1765.32 1765.31 1765.48 1766.32 1766.61 1766.78 1766.94 1767.06 1767.18 1767.37 1767.45 1767.50 1767.57 1767.61 1767.66 1767.70 1767.70 1764.96 1767.73 1767.76 1767.81 1767.82 1768.11 1769.53 1770.16 1770.78 1770.97 1771.09 1771.25 1771.37 1771.45 1771.49 1772.71 1775.68 1777.60 1778.09 1778.33 1778.56 1778.96 1779.15 1779.74 1780.01 1780.18 1780.40 1780.57 1780.78 1781.24 1781.40 —— 1781.40 1767.73 A No gage-height record 117 RIO DE LA PLATA BASIN 50043000 RIO DE LA PLATA AT PROYECTO LA PLATA, PR LOCATION.—Lat 18°09'37", long 66°13'44", Hydrologic Unit 21010005, at upstream side of bridge on Highway 173, 0.4 mi (0.$ km) northeast of Proyeeto La Plata, and 2.5 mi (4.0 km) upstream from Rio Usabdn. DRAINAGE AREA.--63.0 mi 1 (163.2 km2 )/ excludes 8.2 mi 2 (21.1 km 1 ) upstream from Carite Reservoir, the flow of which is diverted to Rio Guamani. WATER-DISCHARGE RECORDS PERIOD OF RECORD.—1958 (occasional measurements only), February 1959 to March 1960 (monthly measurements only). April I960 to current year. GAGE.—Water-stage recorder. Elevation of gage is 850 ft (259 m), from topographic map. Prior to Mar. 29, 1961, wire-weight gage read twice daily at sane site and datum. REMARKS.--Records poor. The Puerto Rico Aqueduct and Sewer Authority operates a pumping plant about 5 mi (8 km) upstream which can divert as much as 23 ft'/s (0.65 m5 /s) into Cidra Reservoir. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY NOV DEC MAR AUG SEP 1 ell e!7 2 elO el6 3 e9.4 el5 4 e8.6 e!5 5 e8.6 e!5 6 e8.8 e!8 7 e8.6 e29 8 e9.8 644 9 elO 640 10 e!5 639 11 e24 631 12 e!7 «43 13 ell 627 14 e20 621 15 e!4 620 16 e9.8 e20 17 e9.8 6 19 18 e9.8 e 13 19 e!48 ell 20 e58 e!2 21 e43 elO 22 e21 e9.8 23 el800 e9.6 24 e990 elO 25 e410 elO 26 e!60 e9.9 27 e98 elO 28 e58 e9.9 29 e38 e 17 30 e26 e!8 31 e21 - — TOTAL 4086.2 579.2 MEAN 132 19.3 MAX 1800 44 MIN 8.6 9.6 AC-FT 8100 1150 CFSM 2.41 .35 IN. 2.77 .39 e22 e22 e66 e30 621 e20 e!9 e!7 e!4 e!2 elO elO e!3 e!2 elO elO 612 ell elO e9.9 ell elO elO ell e!3 e!3 e!2 el 6 e!5 e!9 e!3 493.9 15.9 66 9.9 980 .29 .34 STATISTICS OF MONTHLY MEAN DATA MEAN 200 172 MAX 2164 831 (WY) 1971 1978 MIN 7.82 12.1 (WY) 1969 1982 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 96.0 565 1971 9.16 1990 FOR e!2 e!5 616 e20 e22 621 621 e!9 e!8 e24 e35 e27 e28 e20 e!2 e9.8 e8.2 e7.6 e8.2 e8.8 e8.8 e8.2 e8.2 e8.2 e9.8 e9.8 638 641 628 623 e9.8 545.4 17.6 41 7.6 1080 .32 .37 e7.6 e6.6 e6.2 e5.2 e5.2 e5.2 e5.6 e7.8 e!3 elO e7.8 e7.0 e7.6 e7.2 e7.2 e6.4 e8.0 e8.8 e9.2 elO ell e64 e38 e!7 ell e310 e448 e88 ___ ___ 1138.6 40.7 448 5.2 2260 .74 .77 FOR WATER YEARS 1960 63.2 519 1992 7.78 1990 44.6 195 1989 7.65 1990 e43 e!7 69.9 69.8 69.8 e!4 elO e9.6 elO e!5 e30 e23 e33 e58 e60 e35 el9 e!3 elO e9.4 e8.8 elO 614 e!5 614 ell elO elO elO e9.8 elO 561.1 18.1 60 8.8 1110 .33 .38 - 1995 32.8 120 1972 4.72 1977 1994 CALENDAR YEAR 9598. 26. 1800 4. 6. 19040 6. 29 11 7. 0 3 Oct 23 8 Jun 24 1 Jul 30 48 52 0 e9.8 e9.0 e7.4 e6.4 e6.8 e6.8 e7.4 e7.4 e6.4 e6.2 e6.2 e32 e56 e!6 e9.8 ellO e64 e24 e!8 e!7 e!6 e!5 e!5 e9.8 e6.8 e5.8 e5.8 e4.9 e4.3 e4.6 --- 514.6 17.2 110 4.3 1020 .31 .35 e4.9 e5.8 e6.4 e7.2 e!9 e!4 e99 elOO e230 eieo ellO e!4 e6.8 e58 elOO 631 e!4 e!2 e38 e!20 elOO e23 ell 68.8 67.4 68.2 67.8 e58 e32 e35 e98 1559.3 50.3 230 4.9 3090 .92 1.06 e42 e40 e240 e!20 e50 e29 e!7 e!8 ell e!2 e!3 ell elO ell ell ell ell e!2 e!2 elO e9.8 ell elO e8.8 e7.8 e7.8 e240 e270 e68 e30—— 1354.2 45.1 270 7.8 2690 .82 .92 e!9 e!2 ell elO e9.2 elO ell elO elO e9.2 elO e!3 e!7 e58 e!8 e!9 e20 e!5 e!3 elO e8.8 *44 e54 e!9 ell e9.8 e33 e210 el60 e88 e70 1012.0 32.6 210 8.8 2010 .60 .69 e68 e29 e32 6120 e68 e23 e!3 ell elO elO e8.8 e8.4 e8.2 ellO e40 e23 e!5 e!4 e490 e450 e210 e96 e70 ellO e94 e!60 e60 e68 e96 631 e!7 2563.4 82.7 490 8.2 5080 1.51 1.74 ell elO ellO e60 e94 e2000 e2100 el600 e680 e280 e!30 688 674 652 6354 64990 62970 e980 e380 e240 6230 e200 e240 6440 e200 e240 e220 6140 e290 e!70 --- 19573 652 4990 10 38820 11.9 13.29 , BY WATER YEAR (WY) 48.8 323 1971 6.61 1977 FOR 1995 33980 93 4990 4 5 67400 1 23 160 15 7 101 594 1985 6.66 1968 WATER YEAR .9 .1 Sep 16 .3 Apr 29 .2 Apr 26 .70 .07 .8 91.1 629 1970 4.93 1977 81.4 489 1961 5.30 1977 WATER 100 368 19 20300 2 3 73600 36 72780 1 24 153 28 8 130 642 1961 9.45 1967 YEARS 1960 .3 Sep .6 Jul .2 Jul Jan .39 Jan .83 .91 .8 165 975 1960 11.9 1967 - 1995 1971 1994 6 1960 25 1974 6 1977 5 1992 5 1992 e Estimated 118 RIO DR LA PLATA BASIN 50043000 RIO DE LA PLATA AT PROYECTO LA PLATA, P.R. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 12. .. DEC 05. . . FEB 1995 07. .. APR 11. .. JUN 07. . . ADG 02. . . DATE OCT 1994 12. .. DEC 05. .. FEB 1995 07. . . APR 11. .. JUN 07. . . AU6 02. .. TIME 1230 1245 0925 1010 0745 0910 HARD- NESS TOTAL (H6/L AS CAC03) 140 -- — 160 -- 130 SILICA, DATE OCT 1994 12... DEC 05. .. FEB 1995 07. .. APR 11. .. JUN 07. .. ADG 02. .. K s non-ideal DIS- SOLVED (H6/L AS SIO2) 23 -- -- 16 — 23 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 17 20 5.3 6.1 17 27 CALCIUM DIS- SOLVED (MG/L AS CA) 35 -- -- 39 __ 32 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 244 -- -- 284 -- 204 SPE- CIFIC CON- DUCT- ANCE (US/CM) 414 348 446 475 322 326 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 13 -- -- 14 __ 11 SOLIDS, DIS- SOLVED (TONS PER DAY) 11.5 _- — 4.71 — 14.6 PH WATER WHOLE FIELD (STAND- ARD UNITS) 8.3 8.1 8.0 7.6 7.5 7.8 SODIUM, DIS- SOLVED (MG/L AS NA) 37 -- -_ 44 __ 25 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 17 5 3 2 6 13 TEMPER- ATURE WATER (DEG C) 28.5 26.0 22.5 25.5 27.0 27.0 SODIUM AD- SORP- TION RATIO 1 — — 2 __ 1 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.50 0.30 0.50 0.60 0.55 0.54 TUR- BID- ITY (NTU) 4.6 3.2 1.6 2.5 9.0 7.5 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 3.2 -_ __ 4.3 __ 2.5 PHOS- PHORUS TOTAL (MG/L AS P) 0.620 0.390 0.590 0.800 0.420 0.340 OXYGEN, DIS- SOLVED (MG/L) 9.3 7.2 6.8 5.5 4.0 5.7 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 130 120 150 160 110 120 ARSENIC TOTAL (UG/L AS AS) 1 __ -- <1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 121 89 80 70 52 73 SULFIDE TOTAL (MG/L AS S) <0.5 -- __ <0.5 __ -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) 100 __ -- <100 — -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 15 13 15 17 17 13 SULFATE DIS- SOLVED (MG/L AS SO4) 20 -- _- 22 _- 12 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 60 -- -- 90 -- -- COLI- FORM, FECAL, 0.45 UM-MP (COLS./ 100 ML) 390 K860 280 540 420 K900 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 35 -- -- 49 -- 26 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 — -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 320 840 250 K63 370 970 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 -- — 0.10 -- 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 -- -- RIO DE LA PLATA BASIN 50043000 RIO DE LA PLATA AT PROYECTO LA PLATA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 119 DATE COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS KB) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) OCT 1994 12. .. DEC 05. .. FEB 1995 07. .. APR 11. .. JUN 07. .. AUG 02. .. 240 130 30 70 <0.10 <0.10 <0.010 10 <0.010 (MG/L) 0.06 0.07 120 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR LOCATION.--Lat 18°13'23", long 66°13'30", Hydrologie Unit 21010005, on right bank 50 ft (15 m) upstream from bridge off Highway 167 in the Town of ComerJCo, 0.4 mi (0.6 km) southwest of ComerJCo High School, and 0.2 mi (0.3 km) northeast of Plaza de Comerio. DRAINAGE AREA.--109 mi> (282 km9 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD,--December 1988 to current year. GAGB.--Water-stage recorder and crest-stage gage. Datum of gage is 604.2 ft (184.160 m) above mean sea level. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Filtration plant more or less 1,000 feet upstream from station. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT NOV MAR HAY JUN SEP 1 12 17 2 9.7 16 3 8.6 15 4 8.1 15 5 8.1 15 6 8.3 18 7 8.1 21 8 9.5 42 9 10 39 10 16 37 11 24 30 12 17 41 13 12 26 14 20 21 15 15 20 16 10 20 17 10 19 18 75 14 19 135 12 20 53 13 21 40 11 22 23 9.9 23 1830 9.0 24 e800 11 25 e350 11 26 e!46 10 27 84 11 28 55 10 29 36 18 30 26 18 31 21 —— TOTAL 3880.4 569.9 MEAN 125 19.0 MAX 1830 42 MIN 8.1 9.0 AC-FT 7700 1130 CFSM 1.15 .18 IN. 1.33 .20 STATISTICS OF MONTHLY MEAN MEAN 216 84.1 MAX 866 166 (WY) 1991 1993 MIN 40.6 19.0 (WY) 1992 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 22 22 63 34 26 24 21 17 15 13 11 11 14 13 11 11 14 12 11 10 12 11 11 12 14 14 13 17 16 20 14 529 17.1 63 10 1050 .16 .18 DATA 48.5 112 1993 17.1 1995 FOR 13 16 17 20 22 21 21 19 18 24 35 27 28 20 18 14 11 10 11 12 12 11 11 11 15 15 54 59 40 33 22 660 21.3 59 10 1310 .20 .23 FOR WATER 144 732 1992 21.3 1995 18 16 15 14 14 14 15 21 37 25 19 17 19 18 18 16 20 22 23 26 28 121 72 30 22 564 822 154 ___ ___ --- 2200 78.6 822 14 4360 .72 .75 YEARS 1989 83.7 247 1989 24.4 1990 74 35 22 20 20 29 22 19 21 31 56 45 65 107 114 65 37 26 21 17 16 22 29 30 28 24 22 22 22 21 22 1104 35.6 114 16 2190 .33 .38 - 1995 38.9 75.7 1989 20.6 1993 1994 CALENDAR YEAR 12232. 33. 1830 5. 7. 24260 . 4. 41 17 8. 5 5 Oct 23 8 Jun 25 3 Jul 31 31 19 3 19 17 14 12 13 13 14 13 12 12 12 61 107 32 18 225 94 48 37 36 32 30 29 18 13 11 11 9.5 8.3 8.9 979.7 32.7 225 8.3 1940 .30 .34 , BY WATER 52.7 162 1993 22.3 1991 9.1 11 12 14 37 28 307 341 744 573 353 57 21 191 326 130 46 40 126 409 326 76 38 27 23 26 24 189 101 113 308 5026.1 162 744 9.1 9970 1.49 1.72 YEAR (WY) 105 263 1992 19.7 1994 132 125 743 361 156 86 54 60 38 30 24 21 18 19 20 20 20 22 21 18 17 20 19 15 13 13 261 306 65 31 2748 91.6 743 13 5450 .84 .94 65.8 194 1993 13.2 1994 FOR 1995 WATER YEAR 48127.6 132 6230 8.1 8.6 11500 11.68 8.1 95460 1.22 16.50 309 22 11 Sep 16 Oct 4 Oct 2 Sep 16 Sep 16 Oet 4 20 15 12 11 10 12 13 11 11 9.9 13 15 19 111 34 38 39 31 27 20 16 84 111 36 22 17 66 393 295 160 127 1798.9 58.0 393 9.9 3570 .53 .62 81.4 291 1993 10.4 1994 WATER 100 133 35 14600 5 7 127000 29 5 72800 12 144 32 14 125 56 58 143 63 27 17 13 12 12 10 9.4 9.2 130 46 27 18 17 613 557 236 111 85 152 109 214 73 87 113 42 21 3205.6 103 613 9.2 6360 .95 1.10 63.4 114 1993 12.7 1994 YEARS 1989 .3 Jan . 8 Jun .3 Jul Jan .22 Jan . 6 Jun .93 .58 15 14 143 71 110 2430 2470 1990 753 317 156 105 85 61 257 6230 3420 1540 671 410 402 431 418 719 345 409 378 239 526 311 25426 848 6230 14 50430 7.81 8.72 283 848 1995 51.2 1991 - 1995 1993 1994 5 1992 25 1994 31 1994 5 1992 5 1992 24 1994 e Estimated 121 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COHERIO, PR—Continued WATER-QUALITY RECORDS PERIOD OP RECORDS.-- Water years 1989 to current year. PERIOD OP DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGEi October 1989 to September 1995. 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 and during high flow events. EXTREMES FOR PERIOD OP DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 8,800 mg/L Jan. 05, 1992; Minimum daily mean, 1 mg/L November 28, 1994. SEDIMENT LOADS: Maximum daily mean, 950,000 tons (862,000 tonnes) Jan. 05, 1992; Minimum daily mean, 0.04 tons (0.04 tonne) November 28, 1994. EXTREMES POR WATER YEARS 1995.-- SEDIMENT CONCENTRATION: Maximun daily mean, 903 mg/1 September 07, 1995; Minimun daily mean, 1 rog/L November 28, 1994. SEDIMENT LOADS: Maximun daily mean, 18,100 tons (16,400 tonnes) September 16, 1995; Minimun daily mean .04 tons (.04 tonnes) November 28, 1994. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAY 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL 3880.4 —— 5132.76 569.9 —— 23.55 529 —— 16.45 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) OCTOBER 12 9.7 8.6 8.1 8.1 8.3 8.1 9.5 10 16 24 17 12 20 15 10 10 75 135 53 40 23 1830 e800 e350 e!46 84 55 36 26 21 8 6 7 9 10 11 10 10 9 13 15 13 11 11 8 8 7 40 71 19 12 14 757 119 76 48 39 37 35 22 12 .26 .17 .16 .19 .23 .24 .22 .25 .26 .82 .98 .58 .37 .62 .33 .21 .20 22 29 2.7 1.2 .87 4820 e!33 e73 e25 8.8 5.4 3.4 1.6 .70 MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) NOVEMBER 17 16 15 15 15 18 21 42 39 37 30 41 26 21 20 20 19 14 12 13 11 9.9 9.0 11 11 10 11 10 18 18 7 6 7 7 8 10 15 27 23 11 6 21 15 12 10 10 17 28 45 41 31 23 17 12 9 5 2 1 3 11 —— .31 .26 .26 .29 .34 .51 .86 3.1 2.6 1.2 .50 2.3 1.1 .66 .55 .55 .85 1.0 1.4 1.4 .93 .60 .40 .37 .25 .13 .07 .04 .15 .57 DECEMBER 22 22 63 34 26 24 21 17 15 13 11 11 14 13 11 11 14 12 11 10 12 11 11 12 14 14 13 17 16 20 14 13 7 35 14 11 11 10 11 13 14 13 10 8 8 7 7 7 6 6 5 4 3 3 .81 .53 6.2 1.3 .78 .70 .57 .50 .51 .50 .39 .31 .31 .27 .22 .21 .25 .21 .17 .14 .12 .09 .10 .11 .15 .15 .14 .18 .18 .20 .15 e Estimated 122 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) JANDARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 13 16 17 20 22 21 21 19 18 24 35 27 28 20 18 14 11 10 11 12 12 11 11 11 15 15 54 59 40 33 22 4 3 3 3 4 4 4 4 4 7 18 6 4 3 3 3 4 4 4 5 5 6 7 7 8 9 31 58 56 52 29 .13 .14 .15 .18 .21 .23 .23 .21 .19 .48 1.7 .44 .28 .18 .15 .12 .11 .11 .13 .15 .17 .18 .19 .22 .32 .35 6.7 9.2 6.0 4.7 1.8 FEBRUARY 18 16 15 14 14 14 15 21 37 25 19 17 19 18 18 16 20 22 23 26 28 121 72 30 22 564 822 154 ___ ___ 14 7 5 5 4 4 4 4 20 25 23 15 9 6 6 7 8 12 18 28 41 310 401 166 55 350 421 94 ___ ___ . • 2. 1. 1. . . • 1. 2. 3. 135 81 14 3. 722 1260 44 - _ - 69 28 22 18 16 16 16 26 0 6 2 71 46 27 28 29 43 68 2 0 1 3 -- __ -- MARCH 74 35 22 20 20 29 22 19 21 31 56 45 65 107 114 65 37 26 21 17 16 22 29 30 28 24 22 22 22 21 22 15 11 14 17 19 17 10 9 11 20 38 29 42 58 65 56 41 30 22 16 12 9 10 14 17 14 10 7 6 6 6 3. 1. 1. 1. 2. 6. 3. 7. 17 20 10 4. 2. 1. • . 1. 1. . . . . . 4 0 83 90 0 4 57 47 60 3 3 6 6 1 1 2 75 50 51 80 1 3 92 58 40 36 35 36 TOTAL 660 35.35 2200 2275.63 1104 92.30 123 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COHERIO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 19 17 14 12 13 13 14 13 12 12 12 61 107 32 18 225 94 46 37 36 32 30 29 16 13 11 11 9.5 8.3 8.9 APRIL 6 5 5 5 6 6 6 6 6 7 8 12 54 25 18 110 62 31 12 9 6 6 7 7 8 9 10 9 7 6 MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) MAY .29 .24 .19 .17 .19 .21 .23 .21 .19 .21 .26 2.3 17 2.3 .86 89 16 4.0 1.3 .66 .54 .51 .51 .34 .26 .27 .29 .22 .16 .15 9.1 11 12 14 37 28 307 341 744 573 353 57 21 191 326 130 46 40 126 409 326 76 38 27 23 26 24 189 101 113 306 8 11 14 15 43 34 170 191 499 432 185 40 20 78 167 66 30 29 61 321 157 47 25 18 17 17 16 135 53 116 541 4 2 291 195 3240 885 243 6 1 165 179 26 4 3 91 691 169 10 2 1 1 1 1 90 15 67 483 .19 .33 .47 .81 .4 .6 .6 .2 .0 .9 .6 .3 .1 .2 .1 JUNE 132 125 743 361 156 86 54 60 36 30 24 21 18 19 20 20 20 22 21 16 17 20 19 15 13 13 261 306 65 31 73 73 266 174 92 53 31 23 19 15 8 6 7 7 7 8 8 9 9 10 11 12 13 13 11 11 357 60S 111 51 27 28 549 187 40 12 4. 3. 2. 1. . . . • . 1110 807 22 4. - 5 8 0 2 50 35 32 35 38 40 44 51 53 49 51 63 65 52 39 39 4— TOTAL 979.7 139.26 5026.1 6691.80 2748 2605.26 124 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR 20 15 12 11 10 12 13 11 11 9.9 13 15 19 111 34 38 39 31 27 20 16 84 111 36 22 17 66 393 295 160 127 1798.9 48127.6 JULY 27 15 12 13 14 14 14 14 15 15 17 12 12 62 22 24 24 22 18 16 15 42 44 18 15 13 44 184 134 85 66 ... 1.5 .61 .39 .39 .38 .46 .50 .45 .42 .40 .68 .48 1.3 21 2.1 2.6 2.6 1.8 1.3 .87 .67 15 15 1.8 .89 .61 27 209 108 38 26 482.20 65665.63 AUGUST 125 56 58 143 63 27 17 13 12 12 10 9.4 9.2 130 46 27 18 17 613 557 236 111 85 152 109 214 73 87 113 42 21 3205.6 69 38 34 71 40 21 14 14 16 19 17 13 12 63 33 23 14 13 250 308 268 221 61 76 28 108 46 45 71 28 20 24 5.9 5.5 31 7.3 1.6 .69 .50 .55 .60 .47 .34 .32 23 5.0 1.7 .69 .65 746 494 170 68 14 32 9.8 67 9.5 18 26 3.1 1.2 1768.41 MEAN DISCHARGE (CPS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/ DAY) SEPTEMBER 15 14 143 71 110 2430 2470 1990 753 317 156 105 85 61 257 6230 3420 1540 671 410 402 431 418 719 345 409 378 239 526 311 13 12 69 44 54 773 903 449 158 96 59 36 30 29 87 892 434 205 69 31 110 236 166 326 186 194 205 117 256 221 .54 .42 65 13 52 6880 9080 2650 332 85 25 10 6.9 4.8 256 18100 4490 999 130 35 143 284 242 695 174 271 217 77 485 200 25426 46002.66 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR—Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT 725 DATE OCT 1994 23.. . 23.. . 23.. . 23.. . MAY 1995 09.. . SEP 07.. . 07. .. 07.. . 16.. . TIME 0230 0530 1000 1420 2045 1041 1140 1409 0550 DIS- CHARGE, INST. CUBIC FEET PER SECOND 2690 2130 3120 1597 4500 1223 1440 1312 9920 SEDI- MENT, SUS- PENDED (MG/L) 1903 1939 1263 1002 3468 6074 6765 5785 2969 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 13800 11100 10600 4320 42400 20000 26300 20500 79500 SBD. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 52 60 64 76 46 32 38 40 44 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 59 66 72 79 55 45 44 45 54 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 68 73 74 82 63 53 52 51 58 DATE OCT 1994 23. .. 23. .. 23... 23. .. HAY 1995 09. .. SEP 07... 07. .. 07. .. 16... SED. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 77 76 80 84 75 65 63 63 70 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 83 80 81 87 81 77 75 75 79 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 95 98 96 98 96 85 87 87 93 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 98 99.3 98 99.3 98.5 92 94 94 98 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 99. 99. 98. 99. 99. 94 95 95 99. 1 5 7 7 6 5 3 SED. SED. SUSP. SUSP. SIEVE SIEVE DIAM. DIAM. PERCENT PERCENT FINER FINER THAN .500 MM 99. 99. 99. 99. 99. 95 96 97 99. 1. 8 9 4 7 8 7 THAN 00 MM 100 100 100 99. 99. 97 97 98 99. 9 9 9 126 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DATE OCT 1994 23.. . 23.. . 25.. . DEC 01.. . FEB 1995 23.. . MAY 08... 09.. . 10.. . 10.. . 18.. . 20.. . 20... JUN 28... JUL 14.. . AU6 19.. . SEP 06.. . 08.. . 16.. . 17.. . TIME 0350 0730 1547 1540 1720 1515 2145 0005 2235 1430 1621 1910 1750 1514 1940 1050 1545 0220 1704 STREAM- FLOW, INSTAN- TANEOUS (CPS) 2907 3960 175 21 52 231 3240 1540 1480 27 1540 1467 170 56 1867 3837 2610 1923 3291 SEDI- MENT, SUS- PENDED (MG/L) 1250 573 81 92 377 186 2810 1290 275 235 449 1290 541 56 948 1620 274 182 704 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 9810 6130 38 5.2 53 116 24600 5360 1100 17 1870 5160 248 8 4780 16800 1930 945 6260 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 99 96 97 88 99 98 98 99 98 99 99 99 92 95 99 98 98 98 99 727 RIO DE LA PLATA BASIN 50044000 RIO OE LA PLATA NEAR COMERIO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°14'33", long 66°12'28 R , at bridge on Highway 156, 0.56 mi (0.9 km) upstream from dam, about 2.0 mi (3.2 km) northeast of Comerio plaza. DRAINAGE AREA.--139 mi 2 (360 km1 )/ excludes 8.2 «i» (21.1 km1 ) upstream from Carite Reservoir, the flow of which is diverted to Rio Guamani. PERIOD OP RECORD.—Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 06. . . DEC 06. .. FEB 1995 03. .. APR 05. .. JUN 05. .. AUG 01. .. DATE OCT 1994 06. .. DEC 06. .. FEB 1995 03. . . APR 05. .. JUN 05. .. AUG 01... DATE OCT 1994 06. .. DEC 06. .. FEB 1995 03. .. APR 05... JUN 05. .. AUG 01... TIME 1050 1145 0915 0855 1045 0745 HARD- NESS TOTAL (HG/L AS CAC03) 150 -- -- 160 — 120 SILICA, DIS- SOLVED (MG/L AS SI02) 26 -- — 25 -- 22 DIS- CHARGE, INST. CUBIC FEET PER SECOND 21 48 16 12 94 88 CALCIUM DIS- SOLVED (MG/L AS CA) 37 -- -- 36 -- 30 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 261 -_ -- 367 -- 196 SPE- CIFIC CON- DUCT- ANCE (US /CM) 403 403 413 410 312 323 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 15 -- -- 17 -- 11 SOLIDS, DIS- SOLVED (TONS PER DAY) 14.7 -_ -- 12.4 — 46.6 PH WATER WHOLE FIELD (STAND- ARD UNITS) 8.4 8.1 8.1 8.1 7.8 7.8 SODIUM, DIS- SOLVED (MG/L AS NA) 33 __ _- 38 -- 22 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 7 6 3 5 14 23 TEMPER- ATURE WATER (DEG C) 27.0 24.0 22.0 25.0 27.0 27.5 SODIUM AD- SORP- TION RATIO 1 _- — 1 — 0.9 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 1.2 0.20 0.30 0.30 0.69 0.49 TUR- BID- ITY (NTU) 1.0 6.2 1.2 1.7 40 16 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.9 __ __ 3.4 -- 2.9 PHOS- PHORUS TOTAL (MG/L AS P) 0.380 0.200 0.250 0.170 0.220 0.270 OXYGEN, DIS- SOLVED (MG/L) 9.9 8.4 8.8 7.5 6.9 6.7 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CAC03 150 160 150 150 110 120 ARSENIC TOTAL (UG/L AS AS) 2 -- — 1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 123 99 100 93 88 86 SULFIDE TOTAL (MG/L AS S) <0.5 _- -- <0.5 -- -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 10 <10 <10 19 24 SULFATB DIS- SOLVED (MG/L AS S04) 24 — -- 28 — 14 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 60 -- — 70 — -- COLI- PORM, FECAL, 0.45 UM-MP (COLS./ 100 ML) 460 K720 K62000 2100 K1600 570 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 33 -- -- 130 -- 22 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K150 430 600 330 320 810 PLUO- RIDE, DIS- SOLVED (MG/L AS P) 0.10 -- -- 0.10 -- 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 __ -- <1 -- -- K = non-ideal count 128 RIO DE LA PLATA BASIN 50044000 RIO DE LA PLATA NEAR COHERIO, PR—Continue WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 06. .. DEC 06... FEB 1995 03... APR 05. . . JUN 05. .. AUG 01. .. COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS FE) AS PB) AS MN) AS HG) AS SB) AS AG) AS ZN) AS CN) (UG/L) 10 160 150 <1 40 40 <0.10 0.10 <0.010 <0.010 (MG/L) 0.04 0.03 129 RIO DE LA PLATA BASIN 50044830 RIO GUADIANA AT GUADIANA, PR LOCATION.--Lat 18°18'08", long 66°13'24", Hydrologie Dnit 21010005, at left bank downstream side of river, 1.3 mi (2.1 km) East of Plaza de Haranjito, 0.9 mi (1.4 km) west from intersection of roads 167 and 164 at km 8.9 and 2.9 mi (4.7 km) northwest from Repress Comerio. DRAINAGE AREA.--9.19 mi 1 (23.80 km1 ). WATER-DISCHARGE RECORDS PERIOD OP RECORD.--JUly 1990 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 230 ft (70 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Mean daily discharge affected by domestic discharges near station. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY DEC JAN FEB 1 1.4 2.7 2 1.2 2.0 3 1.2 2.0 4 1.2 11 5 1.0 4.5 6 .97 7.9 7 47 4.5 8 7.9 43 9 2.3 35 10 1.8 16 11 2.8 19 12 2.0 e!3 13 3.8 e5.8 14 8.5 e4.1 15 4.3 e3.3 16 2.1 e3.0 17 2.4 e2.9 18 10 e2.9 19 27 e2.8 20 18 e2.6 21 6.2 e2.7 22 25 e3.6 23 56 2.6 24 12 2.5 25 5.3 2.9 26 3.7 3.3 27 3.0 5.2 28 2.5 13 29 2.3 36 30 2.1 35 31 2.9 —— TOTAL 267.87 294.8 MEAN 8.64 9.83 MAX 56 43 MIN .97 2.0 AC-FT 531 585 CFSM .94 1.07 IN. 1.08 1.19 22 13 28 18 13 12 7.0 5.4 5.1 4.2 3.5 3.3 3.1 2.9 2.7 2.6 2.8 2.4 2.3 1.7 1.7 1.9 1.6 1.6 1.6 1.8 1.7 2.3 1.9 1.6 1.7 174.3 5.62 28 1.6 346 .61 .71 STATISTICS OF MONTHLY MEAN DATA MEAN 25.5 13.6 MAX 98.7 18.4 (WY) 1991 1993 MIN 4.51 7.32 (WY) 1992 1992 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 13.0 27.5 1993 5.62 1995 FOR 2.1 2.0 1.8 1.8 1.5 1.6 1.4 1.9 1.6 e9.6 e4.8 9.2 4.4 2.6 2.2 1.9 1.6 2.0 16 9.2 3.4 2.4 2.0 2.1 2.2 71 30 73 14 6.1 4.1 289.5 9.34 73 1.4 574 1.02 1.17 FOR WATER 17.5 42.5 1992 5.70 1994 3.5 3.3 2.8 2.6 2.6 2.6 3.4 3.7 2.9 2.3 2.8 2.2 2.2 2.0 2.4 2.6 2.3 2.9 8.8 5.4 17 6.7 2.7 2.9 57 144 151 165 ___ --- 609.6 21.8 165 2.0 1210 2.37 2.47 YEARS 1990 • 14.8 31.7 1991 6.39 1992 25 10 5.9 5.8 5.8 4.6 5.1 5.3 4.8 100 45 25 101 50 22 12 8.9 7.0 5.5 4.2 4.0 3.3 3.3 2.6 2.8 2.3 3.3 2.6 2.4 2.2 1.8 483.5 15.6 101 1.8 959 1.70 1.96 - 1995 10.4 15.6 1995 3.96 1994 1994 CALENDAR YEAR 1866. 5. 84 . 1. 3700 7. 8. 2. 1. 85 11 Feb 27 97 Oct 6 1 Jul 20 56 56 3 8 3 1.9 1.6 1.7 2.0 2.2 2.1 2.1 2.0 11 2.7 2.6 23 3.5 2.6 2.4 30 6.6 2.6 2.5 2.5 2.5 2.7 2.0 1.9 1.5 1.8 2.1 2.1 1.8 1.8 --- 127.8 4.26 30 1.5 253 .46 .52 1.7 1.7 1.7 12 4.6 2.1 26 122 27 5.4 3.6 2.3 1.9 13 81 48 303 70 18 14 8.8 6.2 6.1 5.6 6.1 5.2 5.1 4.5 4.3 7.5 6.3 824.7 26.6 303 1.7 1640 2.89 3.34 5.0 14 7.8 5.4 4.2 3.9 3.6 3.4 3.3 3.3 2.8 2.8 3.1 2.7 3.4 2.8 2.9 2.3 2.2 2.5 2.8 2.2 2.2 2.0 1.9 2.0 3.5 3.7 2.4 2.1 --- 106.2 3.54 14 1.9 211 .39 .43 1.8 1.7 8.2 12 3.4 2.5 2.4 1.9 1.6 1.6 3.5 2.2 2.3 2.6 1.8 1.4 1.3 1.2 1.5 25 9.0 12 6.1 5.6 4.1 4.1 11 42 25 7.9 6.4 213.1 6.87 42 1.2 423 .75 .86 4.6 8.0 20 8.3 5.3 512 3.5 3.1 3.2 3.2 3.0 3.1 2.7 3.4 3.7 3.2 4.3 4.1 7.7 4.3 3.0 3.6 24 31 19 9.6 7.0 5.6 5.4 4.5 68 284.6 9.18 68 2.7 565 1.00 1.15 19 11 8.7 5.1 26 274 51 21 11 7.0 6.4 7.0 5.7 4.7 36 417 49 24 15 13 10 8.5 10 7.4 7.1 6.6 9.5 8.3 8.5 7.5 --- 1095.0 36.5 417 4.7 2170 3.97 4.43 , BY WATER YEAR (WY) 18.0 52.4 1993 4.26 1995 FOR 1995 4770 13 417 1 2710 9 9460 1 19 25 3 1 30.5 87.2 1993 2.16 1994 WATER YEAR .97 .1 Sep 16 .97 Oct 6 . 7 Jan 3 May 17 .63 May 17 .42 .31 .6 .8 7.03 19.5 1993 1.49 1994 10.1 23.5 1993 1.45 1994 WATER 15 24 5 536 1 6670 13 11010 1 22 27 5 2 7.29 9.53 1993 3.35 1994 YEARS 1990 .2 .5 .96 Jan .97 Oct .1 Jul Jan . 3 6 Jan .65 .46 .8 .1 14.5 36.5 1995 3.57 1994 - 1995 1993 1994 5 1992 6 1994 20 1994 5 1992 5 1992 Estimated 130 RIO DB LA PLATA BASIN 50044830 RIO GUADIANA AT GUADIANA, PR—Continued HATER -QUALITY RECORDS PERIOD OP RECORDS.-- Hater years 1990 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: August 01, 1990 to September 1995. INSTRUMENTATION.-- Automatic sediment sampler since 1990. REMARKS. — Sediment samples were collected by a local observer on a weekly basis and during high flow events. EXTREMES FOR PERIOD OF DAILY RECORD.— SEDIMENT CONCENTRATION: Maximum daily mean, 3,480 mg/L September 16, 1995; Minimum daily mean, 1 mg/L few days. SEDIMENT LOADS: Maximum daily mean, 18,000tons (16, 300tonnes) Jan. 05, 1992; Minimum daily mean, <0.01 ton (<0.01 tonne) several days. EXTREMES FOR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATION: Maximum daily mean, 3,480 mg/L September 16, 1995; Minimum daily mean, 3 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 7,130 tons (6,468 tonnes) May 17, 1995; Minimum daily mean, 0.01 ton (0.01 tonne) May 01, 1995. SEDIMENT DISCHARGE, SUSPENDED ( TONS / DAY ), HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) OCTOBER 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1.4 1.2 1.2 1.2 1.0 .97 47 7.9 2.3 1.8 2.8 2.0 3.8 8.5 4.3 2.1 2.4 10 27 18 6.2 25 56 12 5.3 3.7 3.0 2.5 2.3 2.1 2.9 9 22 23 18 12 14 361 33 13 21 20 39 19 52 30 12 6 32 279 75 29 240 310 62 29 24 24 25 26 27 21 .03 .07 .07 .06 .03 .04 139 1.0 .08 .11 .23 .21 .49 3.8 .35 .07 .04 1.1 59 3.9 .50 63 62 2.1 .43 .24 .19 .17 .16 .16 .16 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) NOVEMBER 2.7 2.0 2.0 11 4.5 7.9 4.5 43 35 16 19 el3 e5.8 e4.1 e3.3 e3.0 e2.9 e2.9 e2.8 e2.6 e2.7 e3.6 2.6 2.5 2.9 3.3 5.2 13 36 35 16 11 8 78 15 37 16 338 234 67 109 53 24 19 18 18 17 13 9 7 17 33 42 35 25 18 21 43 392 246 .11 .06 .04 8.8 .19 1.7 .20 111 28 3.0 12 e2.1 e.37 e.21 e.16 e.15 e.14 e.10 e.07 e.05 e.13 e.31 .30 .23 .19 .16 .47 1.9 67 28 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/ DAY) DECEMBER 22 13 28 18 13 12 7.0 5.4 5.1 4.2 3.5 3.3 3.1 2.8 2.7 2.6 2.8 2.4 2.3 1.7 1.7 1.9 1.6 1.6 1.6 1.8 1.7 2.3 1.9 1.6 1.7 93 78 249 83 46 46 25 17 16 15 16 17 19 37 17 11 11 10 10 7 9 13 19 28 30 31 33 34 35 36 26 5.4 2.8 50 4.1 1.6 1.5 .48 .25 .22 .17 .15 .15 .16 .28 .12 .07 .08 .07 .06 .03 .04 .07 .08 .12 .13 .16 .15 .21 .18 .15 .11 267.87 338.79 294.8 267.14 174.3 69.09 e Estimated 131 RIO DE LA PLATA BASIN 50044830 RIO GUADIANA AT GUADIANA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 2.1 2.0 1.8 1.8 1.5 1.6 1.4 1.9 1.6 e9.6 e4.8 9.2 4.4 2.6 2.2 1.9 1.6 2.0 16 9.2 3.4 2.4 2.0 2.1 2.2 71 30 73 14 6.1 4.1 16 11 11 12 10 7 6 5 6 41 17 38 15 11 10 9 8 8 171 33 31 36 32 28 24 801 204 697 50 13 9 .09 .06 .05 .05 .04 .03 .02 .03 .02 el. 6 e.22 1.4 .19 .08 .06 .05 .03 .05 31 1.1 .29 .23 .17 .16 .15 217 23 182 2.1 .22 .10 MEAN DISCHARGE (CPS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) FEBRUARY 3.5 3.3 2.8 2.6 2.6 2.6 3.4 3.7 2.9 2.3 2.8 2.2 2.2 2.0 2.4 2.6 2.3 2.9 8.8 5.4 17 6.7 2.7 2.9 57 144 151 165 ___ ___ ___ 8 8 7 7 6 5 5 5 6 6 7 7 8 8 9 9 10 10 26 21 114 25 14 10 406 1110 924 663 ___ ___ .08 .07 .05 .05 .04 .04 .05 .05 .05 .04 .05 .04 .04 .05 .06 .07 .06 .08 1.7 .37 11 .54 .10 .08 219 1920 718 536 ___ .__ MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MARCH 25 10 5.9 5.8 5.8 4.6 5.1 5.3 4.8 100 45 25 101 50 22 12 8.9 7.0 5.5 4.2 4.0 3.3 3.3 2.6 2.8 2.3 3.3 2.6 2.4 2.2 1.8 45 27 22 18 15 13 12 10 12 786 392 80 849 101 36 35 24 14 9 9 11 12 12 10 9 7 6 5 7 6 5 3.4 .76 .35 .28 .24 .16 .16 .15 .16 750 74 5.5 289 17 2.2 1.2 .60 .28 .13 .10 .11 .11 .11 .07 .07 .05 .06 .04 .04 .04 .02 TOTAL 289.5 —- 461.59 609.6 —— 3407.76 483.5 —- 1146.39 e Estimated 132 DAY 50044830 RIO DE LA PLATA BASIN RIO GUADIANA AT GUADIANA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) APRIL 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1.9 1.6 1.7 2.0 2.2 2.1 2.1 2.0 11 2.7 2.6 23 3.5 2.6 2.4 30 6.6 2.6 2.5 2.5 2.5 2.7 2.0 1.9 1.5 1.8 2.1 2.1 1.8 1.8 ___ 4 5 7 10 9 7 6 5 94 13 9 256 68 8 6 270 51 33 33 32 21 12 9 11 13 13 6 3 3 3 ___ .02 .02 .03 .05 .05 .04 .03 .03 23 .10 .07 29 .66 .06 .04 158 1.1 .23 .22 .22 .14 .09 .05 .05 .05 .07 .03 .02 .02 .02 ___ MEAN DISCHARGE (CPS) 1 1 1 12 4 2 26 122 27 5 3 2 1 13 81 .48 303 70 18 14 8 6 6 5 6 5 5 4 4 7 6 .7 .7 .7 .6 .1 .4 .6 .3 .9 .8 .2 .1 .6 .1 .2 .1 .5 .3 .5 .3 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) HAY 3 3 4 186 100 6 222 952 144 37 26 15 9 112 816 388 1560 186 65 38 22 13 12 14 30 18 17 17 16 31 11 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) JUNE 29 1 63 1150 19 18 506 70 7130 44 3 1 .01 .02 .02 .9 .03 .54 .25 .10 .05 .2 .5 .53 .22 .20 .20 .54 .25 .24 .20 .19 .83 .21 5. 14 7. 5. 4. 3. 3. 3. 3. 3. 2. 2. 3. 2. 3. 2. 2. 2. 2. 2. 2. 2. 2. 2. 1. 2. 3. 3. 2. 2.— 0 8 4 2 9 6 4 3 3 8 8 1 7 4 8 9 3 2 5 8 2 2 0 9 0 5 7 4 1 - 6 73 50 41 33 30 29 28 23 17 13 10 8 6 6 7 7 8 6 7 14 12 11 10 9 7 14 15 8 7 ___ .08 5.3 1.1 .61 .38 .31 .28 .26 .20 .16 .10 .08 .07 .05 .06 .05 .06 .05 .04 .06 .10 .07 .06 .05 .04 .04 .28 .16 .05 .04 --- TOTAL 127.8 213.51 824.7 9040.23 106.2 10.19 RIO DE LA PLATA BASIN 133 50044830 RIO GUADIANA AT GUADIANA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- DISCHARGE TRATION DAY (CPS) (MG/L) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR 1.8 1.7 8.2 12 3.4 2.5 2.4 1.9 1.6 1.6 3.5 2.2 2.3 2.6 1.8 1.4 1.3 1.2 1.5 25 9.0 12 6.1 5.6 4.1 4.1 11 42 25 7.9 6.4 213.1 4770.97 JULY 7 6 42 84 32 16 9 7 6 5 13 9 8 8 7 7 6 - 6 5 223 34 51 33 30 27 24 41 371 153 33 27 —— SEDIMENT DISCHARGE (TONS/ DAY) MEAN DISCHARGE (CPS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) AUGUST .03 .03 3.0 9.8 .31 .11 .06 .04 .02 .02 .23 .05 .05 .05 .03 .02 .02 .02 .02 67 1.0 2.2 .54 .45 .30 .29 1.6 114 17 .70 .47 219.46 25943.45 4.6 8.0 20 8.3 5.3 5.2 3.5 3.1 3.2 3.2 3.0 3.1 2.7 3.4 3.7 3.2 4.3 4.1 7.7 4.3 3.0 3.6 24 31 19 9.6 7.0 5.6 5.4 4.5 68 284.6 19 38 155 28 17 21 11 10 9 8 8 7 6 11 14 11 11 16 31 14 9 13 192 240 101 35 22 18 14 10 1020 —— .23 2.4 21 .63 .24 .41 .10 .08 .08 .07 .06 .06 .05 .15 .14 .10 .13 .18 .68 .16 .07 .13 42 37 10 .93 .42 .27 .21 .13 1680 1798.11 MEAN DISCHARGE (CPS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MO/L) (TONS/DAY) SEPTEMBER 19 11 8.7 5.1 26 274 51 21 11 7.0 6.4 7.0 5.7 4.7 36 417 49 24 15 13 10 8.5 10 7.4 7.1 6.6 9.5 8.3 8.5 7.5 —— 1095.0 128 55 35 18 262 2250 374 76 39 26 23 20 17 15 346 3480 447 95 27 39 78 50 24 19 19 18 145 19 9 6 — - —— 20 2.9 1.0 .25 49 3390 60 4.4 1.1 .49 .39 .37 .27 .19 81 5270 69 6.4 1.1 1.3 2.2 1.2 .63 .37 .36 .32 6.2 .42 .20 .13 --- 8971.19 134 RIO DB LA PLATA BASIN 50044030 RIO GUADIANA AT GUADIANA, PR--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DATE FBB 1995 25.. . APR 16.. . MAY 15.. . 17... AUG 31.. . SEP 16. . . TIME 1505 2035 1625 1020 1435 0230 DIS- CHARGE, INST. CUBIC FEET PER SECOND 400 202 339 2570 413 276 SEDI- MENT, SUS- PENDED (MG/L) 3157 3620 6106 20105 44100 34774 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 4090 1970 5590 140000 49200 25900 SBD. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 34 40 32 22 20 12 SBD. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 47 57 45 26 30 15 SBD. SUSP. FALL DIAM. PERCENT FINER THAN .000 MM 50 70 50 30 50 16 DATE FBB 1995 25... APR 16. .. MAY 15.. . 17.. . AUG 31.. . SEP 16.. . SBD. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 76 04 74 40 64 25 SBD. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 05 00 05 52 -- 30 SBD. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 95 99 95 66 07 62 SBD. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 90 99.4 99 09 96 93 SBD. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 99 99.6 99.6 96 90 90 SBD. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99.0 99.0 99.9 90 99 99 SBD. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 99.9 99.9 99.9 99 99.7 99.7 RIO DS LA PLATA BASIN 50044630 RIO GUADIANA AT GUADIANA, PR--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT 735 DATE OCT 1994 07.. . 23... NOV 09.. . DEC 02.. . FEB 1995 25.. . MAR 10.. . APR 16.. . MAY 15.. . 15.. . 16.. . 17.. . 17... JDL 20.. . AUG 31.. . SEP 08... 16... 25... TIME 1705 1502 1433 1405 1430 1615 1930 1730 2010 1622 1730 2250 1600 1540 1045 0630 1605 STREAM- FLOW, INSTAN- TANEOUS (CFS) 246 47 76 12 391 556 335 227 167 91 575 347 205 440 20 636 7.5 SEDI- MENT, SUS- PENDED (MG/L) 1260 120 429 66 1050 2010 3630 3010 1020 742 9930 633 1940 5050 422 7390 216 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 650 15 66 2.8 1110 3030 3060 1640 460 162 15400 760 1070 6000 23 12700 4 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 99 63 97 99 97 96 95 96 93 95 65 94 91 92 97 64 92 136 RIO DE LA PLATA BASIN 50044850 RIO GDADIANA NEAR NARANJITO, PR WATER-QUALITY RECORDS LOCATION.—Lat 1B°1B'39'> , long 66°13'28 M , 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 mi 1 (10.3 km1 ). PERIOD OF RECORD.--Water year 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 11. . . DEC 06. .. FEB 1995 03. .. APR 05... JUN 05. .. AUO 01. .. DATE OCT 1994 11. .. DEC 06. .. FEB 1995 03. .. APR 05. .. JUN 05. .. AUO 01. .. DATE OCT 1994 11... DEC 06. .. FEB 1995 03. .. APR 05. . . JUN 05... AUO 01. .. TIME 0845 1300 1040 1115 1240 0910 HARD- NESS TOTAL (MO/L AS CACO3) 180 -_ -- 160 -- 150 SILICA, DIS- SOLVED (MO/L AS SI02) 27 -- -- 26 -- 24 DIS- CHARGE, INST. CUBIC FEET PER SECOND 2.6 12 3.6 4.6 5.0 6.6 CALCIUM DIS- SOLVED (MO/L AS CA) 45 _- -- 36 -- 34 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 274 -- -- 267 -- 206 SPE- CIFIC CON- DUCT- ANCE (US /CM) 429 369 408 390 373 338 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 17 -_ — 16 -- 15 SOLIDS, DIS- SOLVED (TONS PER DAY) 1.92 -- -- 3.28 -- 3.68 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.8 7.9 8.0 7.8 8.1 7.9 SODIUM, DIS- SOLVED (MG/L AS NA) 30 __ -- 22 -- 17 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 10 18 <1 272 3 30 TEMPER- ATURE WATER (DEG C) 24.0 24.5 22.0 25.0 26.5 26.0 SODIUM AD- SORP- TION RATIO 1 __ __ 0.8 -- 0.6 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.40 0.30 0.20 0.30 0.27 0.31 TUR- BID- ITY (NTU) 1.0 23 1.5 260 1.5 27 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 4.8 __ -- 3.5 -- 2.7 PHOS- PHORUS TOTAL (MG/L AS P) 0.510 0.260 0.310 0.250 0.190 0.150 OXYGEN, DIS- SOLVED (MG/L) 5.8 7.8 8.7 7.1 7.4 7.1 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CAC03 130 110 140 140 130 120 ARSENIC TOTAL (UG/L AS AS) 2 — -- 2 -- — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 68 93 99 87 92 87 SULFIDE TOTAL (MG/L AS S) <0.5 __ __ <0.5 -- — — BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- 100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 13 <10 28 13 12 SULFATE DIS- SOLVED (MG/L AS SO4) 30 _- __ 44 -- 17 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 50 -- -- 40 -- — COLI- FORM, FECAL, 0.45 UH-MF (COLS./ 100 ML) 22000 330000 520 5800 2000 510 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 42 -- -- 35 -- 24 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 2000 9900 490 76000 820 K2000 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 -- -- 0.10 -- 0.20 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- 14 -- -- K • non-ideal count RIO DE LA PLATA BASIN 50044850 RIO G0ADIANA NEAR NARANJITO, PR--Continued HATER-QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 737 COPPER, TOTAL RECOV- ERABLE (UG/L AS CO) IRON, TOTAL RECOV- ERABLE (UG/L AS FE) LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) SELE- NIUM, TOTAL (UG/L AS SE) SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) CYANIDE TOTAL (MG/L AS CN) PHENOLS TOTAL (UG/L) METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) OCT 1994 11. .. DEC 06. .. FEB 1995 03. .. APR 05... JUN 05. . . AUG 01. .. 40 150 9500 <1 40 450 <0.10 0.20 <0.010 40 <0.010 0.05 0.06 138 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 ml (4.3 km) West of Road 167, km 15.3, Buena Vista, Bayam6n, 5.2 mi (8.4 km) east of Plaza de Corozal. DRAINAGE AREA.--181 mi> (469 km 1 ). ELEVATION RECORDS PERIOD OP RECORD.—February 1989 to current year. Prior to October 1994, published as Lago La Plata at Daatsite. GAGE.--Hater-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 hra3 ) 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. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 167.02 ft (50.91 m), Jan. 5, 1992; minimum elevation, 107.95 ft (32.90 m), Feb. 21, 1995. EXTREMES FOR CURRENT YEAR.--Maximum elevation, 164.60 ft (50.17 m), Sept. 30; minimum elevation, 107.95 ft (32.90 m), Feb. 21. Capacity Table (based on data from Puerto Rico Aqueduct and Sewer Authority) Elevation, in feet 98.43 131.24 154.60 Contents, in acre-feet 2,760 11,360 22,720 Elevation, in feet 164.05 170.61 175.52 Contents, in acre-feet 28,550 33,160 37,040 ELEVATION (FEET NGVD), HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES DEC JAN MAR APR MAY JOL AUG SEP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX MIN 116.33 116.22 116.07 115.96 115.81 115.63 116.24 116.28 116.18 116.06 115.97 115.97 115.95 115.93 115.96 115.85 115.78 115.82 117.06 118.31 118.97 119.41 128.91 130.81 131.66 132.26 132.08 131.98 131.81 131.56 131.29 132.26 115.63 116.33 116.22 116.07 115.96 115.81 115.63 116.24 116.28 116.18 116.06 130.96 130.89 130.96 130.69 130.32 129.93 129.55 129.39 129.32 129.29 124.13 124.19 124.43 124.69 124.85 124.93 124.89 124.79 124.59 124.33 117.04 116.75 116.37 116.06 115.79 115.52 115.21 114.95 114.66 114.55 112.99 112.75 112.63 112.34 112.11 111.73 111.52 111.22 110.98 111.51 123.46 123.69 124.44 124.39 124.20 124.06 123.94 123.81 123.74 124.71 124.79 124.60 124.28 123.96 123.61 123.35 122.98 122.67 122.35 122.12 119.82 119.49 119.16 119.14 118.99 118.81 119.19 122.08 124.23 127.41 139.84 140.01 141.69 142.52 142.75 142.74 142.66 142.54 142.42 142.28 138.90 138.64 138.42 138.29 138.06 137.82 137.53 137.22 136.90 136.58 136.95 137.18 137.56 137.61 137.55 137.38 137.18 136.92 136.71 136.41 140.51 140.43 140.25 140.33 140.48 152.19 159.22 160.93 160.39 159.92 129.24 129.13 128.86 128.56 128.23 127.91 127.58 127.24 126.86 126.44 126.03 125.66 125.28 124.91 124.51 124.08 123.79 123.54 123.20 122.96 122.62 122.26 121.93 121.58 121.25 120.93 120.58 120.20 119.83 119.47 114.41 114.44 114.25 114.04 113.83 113.48 113.14 113.00 113.00 113.00 112.61 112.31 111.91 111.58 111.21 111.42 111.00 110.52 109.98 109.60 109.07 108.99 108.89 108.74 108.20 108.60 108.81 108.72 108.61 108.95 124.74 124.59 125.24 125.86 126.26 126.38 126.42 126.29 126.24 126.15 126.08 125.88 125.77 126.04 126.05 121.84 121.88 121.94 121.90 121.71 122.41 122.61 122.58 122.47 122.34 122.18 122.12 122.32 122.22 121.95 129.11 129.23 129.25 129.24 132.05 133.26 136.26 A 136.96 137.85 139.37 139.50 139.44 139.31 A 142.10 141.91 141.69 141.46 141.27 141.10 140.88 140.65 140.43 140.22 139.98 139.73 139.45 139.19 138.92 136.29 136.01 135.72 135.51 135.33 135.38 135.12 134.88 134.61 134.81 134.81 134.70 134.79 134.70 134.52 136.15 135.86 135.54 135.26 135.18 135.10 134.96 134.90 135.97 137.65 138.02 138.12 138.51 139.07 139.33 159.78 159.86 159.63 159.60 155.96 160.12 160.17 160.81 161.80 162.25 162.31 162.80 163.08 163.50 163.21 132.26 132.08 131.98 131.81 131.56 131.29 124.12 123.79 123.55 123.52 123.85 ___ 119.11 118.74 118.43 118.08 117.80 117.35 111.98 112 . 18 113.03 113.44 113.35 113 . 14 112.45 119.48 122.79 ___ 125.77 125.53 125.24 124.88 124.51 124.86 121.62 121.23 120.91 120.50 120.18 ___ 139.13 139.03 139.04 139.04 139.17 139.66 138.63 138.51 139.40 139.36 139.16 ___ 134.28 134.28 135.69 136.67 136.91 136.88 139.59 139.61 139.50 139.54 139.46 140.47 163.59 163.75 163.61 164.23 163.91 _ — - 130.96 123.52 124.93 117.35 117.04 111.21 122.79 108.20 126.42 123.46 124.79 120.18 142.75 138.51 138.90 134.28 140.47 134.90 164.23 140.25 A No gage-height record RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM, PR 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, Bayamon, 5.0 mi (8.0 km) east of Plaza de Corozal, 3.0 mi (4.8 km) northeast of Plaza de Naranjito. DRAINAGE AREA.--173 mi 2 (448 km2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.—July 1989 to current year. GAGE.--Water-stage recorder. Elevation of gage is 164 ft (30 m), from topographic map. REMARKS.--Records poor. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. Gage-height satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 139 OCT JUN SEP 1 .00 .00 2 .00 .00 3 .00 .00 4 .00 .00 5 .00 .00 6 .00 .00 7 .06 .00 8 .06 .00 9 .01 .01 10 .00 .00 11 .00 .00 12 .00 .00 13 .00 .00 14 .00 .00 15 .00 .00 16 .00 .00 17 .00 .00 18 .01 .00 19 .00 .00 20 .11 .00 21 .06 .00 22 4.3 .00 23 7.9 .00 24 .09 .00 25 .04 .00 26 .02 .00 27 .01 .00 28 .01 .00 29 .00 .04 30 .00 .07 31 .01 —— TOTAL 12 . 69 0 . 12 MEAN .41 .004 MAX 7.9 .07 HIN .00 .00 AC-FT 25 .2 CFSH .00 .00 IN. .00 .00 STATISTICS OF MONTHLY MEAN MEAN 234 80.8 MAX 1107 225 (WY) 1991 1993 MIN .048 .004 (WY) 1992 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 0.00 .000 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .01 .01 .00 .00 .00 .00 .00 .00 .00 .01 .01 .01 .01 .00 .00 .00 .42 .24 8.6 18 .62 .16 28.10 .91 18 .00 56 .01 .01 DATA FOR WATER 44.1 161 1993 .000 1995 FOR 298 1581 1992 .19 1990 .05 .02 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .01 .02 .06 .02 .00 .00 .00 .00 2.9 .91 ___ ___ 3.99 .14 2.9 .00 7.9 .00 .00 YEARS 1989 44.2 222 1991 .14 1995 .04 .01 .00 .00 .00 .03 .05 .02 .01 .03 .06 .03 .09 .15 .08 .03 .02 .01 .01 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 0.67 .022 .15 .00 1.3 .00 .00 - 1995 22.8 83.2 1990 .022 1995 1994 CALENDAR YEAR 792. 2. 110 f 1570 5. . . 12 17 Jan 24 00 Mar 18 00 Mar 18 013 17 5 00 00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .14 .06 .03 .02 .01 .01 .01 .02 .02 .01 .00 .00 .00 .00 .00 .00 .00 .00 .00 0.33 .011 .14 .00 .7 .00 .00 .00 .00 .00 2.5 .64 .01 .01 .01 .01 .00 .00 .00 .00 .04 12 10 6.7 8.5 .06 .00 36 3.8 .09 .00 .00 .00 .00 .00 .00 .01 .00 80.38 2.59 36 .00 159 .02 .02 .00 .00 .83 .77 .02 .01 .01 .00 .00 .01 .01 .01 .01 .01 .00 .42 .20 .01 .00 .00 .00 .00 .00 .00 .00 .00 6.3 3.4 .04 .00 12.06 .40 6.3 .00 24 .00 .00 .00 .00 .00 .01 .03 .03 .02 .00 .00 .00 .00 .00 .01 .39 .95 15 1.4 .03 .01 .04 8.5 4.4 .21 .05 .04 .03 .76 5.2 .81 .01 .00 37.93 1.22 15 .00 75 .01 .01 .00 .00 .52 .00 1.3 .00 .05 .00 .00 .00 .00 3.2 .00 e!20 .00 62070 .00 61590 .00 6984 .00 6400 .00 693 .00 274 .00 6151 .00 61980 1.1 9990 .81 4340 .09 1570 .05 216 .00 199 .00 273 .00 140 .21 150 .03 415 .00 326 .00 .03 .00 206 .00 209 .00 115 .00 366 .00 —— 4.16 26180.23 .13 873 1.3 9990 .00 .00 8.3 51930 .00 5.05 .00 5.64 , BY WATER YEAR (WY) 46.0 231 1993 .011 1995 FOR 1995 26360 72 9990 20400 17 52290 5 4 164 494 1993 .000 1994 WATER YEAR .66 .2 Sep 16 .00 Oct 1 .00 Oct 10 Sep 16 .26 Sep 16 .42 .67 .3 .00 .00 51.7 220 1993 .002 1994 75.1 384 1993 .037 1994 WATER 106 182 16 27400 127000 34 76470 8 186 19.8 300 104 1047 1993 1989 .020 .001 1989 1991 YEARS 1989 - 1995 1992 .0 1994 Jan 6 1992 .00 Jul 14 1989 .00 Jul 14 1989 Jan 5 1992 .76 Jan 5 1992 .61 .30 .62 .00 e Estimated 140 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA AT BELOW LA PLATA DAM, PR—Continued HATER-QUALITY RECORDS PERIOD OP RECORDS.— Water years 1990 to current year. PERIOD OP DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1989 to September 1995. INSTRUMENTATION.-- Automatic sediment sampler since 1989. EXTREMES POR PERIOD OP DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,180 mg/L Jan. 06, 1992; Minimum daily mean, <.05 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 362,000tons (328,OOOtonnes) Jan. 06, 1992; Minimum daily mean, 0.00 ton (0.00 tonne) several days. EXTREMES POR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,840 mg/L September 16, 1995; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 74,300 tons (67,100 tonnes) September 16, 1995; Minimum daily mean, 0.00 ton (0.00 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) OCTOBER 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 .00 .00 .00 .00 .00 .00 .06 .06 .01 .00 .00 .00 .00 .00 .00 .00 .00 .01 .00 .11 .06 4.3 7.9 .09 .04 .02 .01 .01 .00 .00 .01 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 1 1 1 1 1 1 1 1 .00 .00 .00 .00 .00 .00 •e.Ol •e.Ol •e.Ol .00 .00 .00 .00 .00 .00 .00 .00 •e.Ol .00 •e.Ol •e.Ol .06 .08 .01 .01 .01 .01 .01 .00 .00 •e.Ol NOVEMBER .00 .00 .00 .00 .00 .00 .00 .00 .01 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .04 .07 ___ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ___ .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 •e.Ol •e.Ol DECEMBER .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 TOTAL 12.69 0.14 0.12 •e.Ol 0.00 0.00 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) 141 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 .00 .00 .00 .00 .00 .00 .00 .00 .00 .01 .01 .00 .00 .00 .00 .00 .00 .00 .01 .01 .01 .01 .00 .00 .00 .42 .24 8.6 18 .62 .16 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 4 1 1 .00 .00 .00 .00 .00 .00 .00 .00 .00 <.01 <.01 .00 .00 .00 .00 .00 .00 .00 <. 01 <.01 <.01 <. 01 .00 .00 .00 <.01 <. 01 .16 .25 <. 01 <. 01 FEBRUARY .05 .02 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .01 .02 .06 .02 .00 .00 .00 .00 2.9 .91 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 <.01 <.01 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 < .01 <.01 <.01 <.01 .00 .00 .00 .00 .02 < . 01 MEAN DISCHARGE (CPS) .04 .01 .00 .00 .00 .03 .05 .02 .01 .03 .06 .03 .09 .15 .08 .03 .02 .01 .01 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 MEAN CONCEN- TRATION (MG/L) MARCH 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 SEDIMENT DISCHARGE (TONS/DAY) <.01 <.01 .00 .00 .00 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 TOTAL 28.10 0.41 3.99 0.02 0.67 142 RIO DE IA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .14 .06 .03 .02 .01 .01 .01 .02 .02 .01 .00 .00 .00 .00 .00 .00 .00 .00 .00 --- 0.33 APRIL 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ___ MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MAY .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .01 .01 .01 .01 .01 .01 .01 .01 .01 <.01 .00 .00 .00 .00 .00 .00 .00 .00 .00 <.01 .00 .00 .00 2.5 .64 .01 .01 .01 .01 .00 .00 .00 .00 .04 12 10 6.7 8.5 .06 .00 36 3.8 .09 .00 .00 .00 .00 .00 .00 .01 .00 80.38 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 3 2 2 1 1 7 1 1 1 1 1 1 1 1 1 1 ___ .00 .00 .00 .02 <.01 <.01 <.01 <.01 < .01 .00 .00 .00 .00 <.01 .22 .11 .10 .09 <.01 .00 .73 .02 <.01 .00 .00 .00 .00 .00 .00 <.01 .00 1.30 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) JUNE .00 .00 .83 .77 .02 .01 .01 .00 .00 .01 .01 .01 .01 .01 .00 .42 .20 .01 .00 .00 .00 .00 .00 .00 .00 .00 6.3 3.4 .04 .00 —— 12.06 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 ___ .00 .00 <. 01 <. 01 <.01 <.01 <. 01 .00 .00 <.01 <.01 <. 01 <. 01 <. 01 .00 <.01 <. 01 <. 01 .00 .00 .00 .00 .00 .00 .00 .00 .08 .02 <. 01 .00 0.10 143 DAY RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) JULY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 IB 19 20 21 22 23 24 25 26 27 28 29 30 31 .00 .00 .00 .01 .03 .03 .02 .00 .00 .00 .00 .00 .01 .39 .95 15 1.4 .03 .01 .04 8.5 4.4 .21 .05 .04 .03 .76 5.2 .81 .01 .00 TOTAL 37.93 YEAR « 26360.66 Estimated 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 1 1 1 1 3 2 1 1 1 1 1 2 1 1 1 - .00 .00 .00 <.01 <.01 <.01 <.01 .00 .00 .00 .00 .00 <.01 <.01 .01 .16 <.01 <.01 <.01 <.01 .10 .03 <.01 <.01 <.01 •c.Ol <.01 .05 <.01 •c.Ol .00 0.35 91291.15 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) AUGUST .00 .52 1.3 .05 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 1.1 .81 .09 .05 .00 .00 .00 .21 .03 .00 .00 .00 .00 .00 .00 .00 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 .00 < .01 .01 < .01 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 •c.Ol •c.Ol •c.Ol < .01 .00 .00 .00 •e.Ol < .01 .00 .00 .00 .00 .00 .00 .00 MEAN DISCHARGE (CPS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/ DAY) SEPTEMBER .00 .00 .00 .00 .00 3.2 e!20 e2070 e!590 e9B4 e400 e93 274 e!51 e!9BO 9990 4340 1570 216 199 273 140 150 415 326 .03 206 209 115 366 ___ 1 1 1 1 1 2 8 254 93 55 20 13 37 30 320 1B40 635 76 77 33 29 22 20 23 25 1 15 13 7 29 . • . e!4 e!730 e394 e!51 e26 e3. 52 e!2 e4030 74300 9640 477 47 IB 42 6. 6. 34 74 <t 76 59 24 69 - 00 00 00 00 00 02 4 2 2 01 -- 4.16 0.01 26180,23 912BB.B2 144 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM, PR—Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DATE SEP 1995 08.. . 13... 14.. . 19... 19.. . 19.. . 20.. . TIME 1337 2125 1025 1549 2158 2312 0126 STREAM- PLOW, INSTAN- TANEOUS (CPS) SEDI- MENT, SUS- PENDED (MG/L) SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) SED. SUSP. SIEVE DIAM. PERCENT PINER THAN .062 MM 644 148 150 267 196 196 196 67 48 48 142 125 123 112 116 19 19 102 66 65 59 79 68 65 96 96 96 98 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HIGHWAY 2 NEAR TOA ALTA, PR 145 LOCATION.—Lat ieo 24'41 n , long 66°15'39 n , Hydrologic Unit 21010005, on left bank, at downstream side of bridge on Highway 2, 1.3 mi ( 2.1 km) downstream from Rio 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.--2 08 mi* (539 km 1 ), excludes 6.2 mi 1 (21.2 km1 ) upstream from La go Carite, flow from which is diverted to Rio Guamani. Area at site used prior to September 25, 1984, 200 mi 1 (518 km 1 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1959 (measurement only), January 1960 to current year. Prior to October 1984, published as Rio 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. to October, 1984, at site about 1.0 mi (1.6 km) upstream at mean sea level datum. Prior 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 bridge construction about 1.0 mi (1.6 km) 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 ft 3 /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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13 14 2 12 14 3 11 14 4 11 15 5 11 15 6 12 14 7 13 13 8 13 17 9 12 35 10 11 35 11 12 19 12 13 16 13 13 14 14 20 14 15 26 13 16 14 13 17 13 14 18 22 14 19 20 14 20 17 15 21 22 14 22 31 22 23 81 14 24 43 12 25 23 13 26 18 19 27 17 16 28 15 16 29 15 29 30 14 66 31 15 TOTAL 583 553 MEAN 18.8 18.4 MAX 81 66 MIN 11 12 AC-FT 1160 1100 CFSM .09 .09 IN. .11 .10 33 23 16 17 17 19 18 26 21 17 17 15 14 14 13 13 12 13 13 11 11 11 8.8 9.2 9.8 9.6 10 13 13 11 9.8 458.2 14.8 33 8.8 909 .07 .09 STATISTICS OF MONTHLY MEAN DATA MEAN 475 432 MAX 4813 2015 (WY) 1971 1985 MIN 18.8 18.4 (WY) 1995 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 326 1352 1971 14.8 1995 FOR 14 16 12 12 12 10 10 10 11 28 31 28 35 17 14 13 13 13 12 9.7 8.7 8.7 12 13 8.5 21 48 85 62 27 18 632.6 20.4 85 8.5 1250 .10 .12 FOR WATER 183 929 1992 16.9 1984 14 12 11 9.5 10 12 15 33 16 11 10 11 11 10 9.2 9.3 8.4 7.2 8.5 21 18 27 16 14 13 28 186 335 —— 886.1 31.6 335 7.2 1760 .16 .16 YEARS 1960 128 409 1989 16.0 1983 173 57 31 70 32 22 19 19 19 18 18 19 28 84 92 44 26 21 19 17 17 18 19 19 16 12 10 9.6 8.9 8.7 8.6 974.8 31.4 173 8.6 1930 .16 .18 - 1995 102 468 1969 8.31 1986 1994 CALENDAR YEAR 7227. 19. 165 7. 9. 14340 1. 33 15 11 9 8 Sep 25 7 Aug 4 5 Jun 8 099 35 9.2 18 58 21 14 12 10 11 11 9.9 10 14 15 11 8.2 8.1 18 18 13 11 9.9 10 7.3 8.1 12 11 9.7 9.4 9.0 8.4 --- 395.2 13.2 58 7.3 784 .07 .07 9.0 10 13 12 17 18 100 51 40 23 15 12 12 11 62 485 133 191 91 46 35 28 20 16 15 18 17 13 15 24 26 1578.0 50.9 485 9.0 3130 .25 .29 86 117 310 272 1030 224 57 41 42 40 35 28 26 26 99 88 33 28 25 25 25 22 21 20 18 18 19 24 19 18 —— 2836 94.5 1030 18 5630 .47 .53 16 15 14 19 24 25 14 12 12 13 13 15 14 14 22 12 9.7 9.4 9.6 10 43 181 39 19 17 20 32 34 69 33 23 802.7 25.9 181 9.4 1590 .13 .15 20 18 37 43 25 21 20 18 20 24 19 19 17 19 20 51 122 69 108 52 32 27 33 87 88 38 29 26 24 30 121 1277 41.2 122 17 2530 .21 .24 101 40 28 26 39 568 259 895 921 466 327 101 131 56 800 13500 4350 2430 250 190 249 171 166 295 358 141 210 243 210 264 27785 926 13500 26 55110 4.64 5.17 , BY WATER YEAR (WY) 190 722 1987 5.07 1984 FOR 1995 38761 106 13500 7 9 25400 19 76880 7 119 18 10 356 1939 1985 7.63 1984 WATER YEAR .6 Sep 16 .2 Feb 18 .1 Feb 13 Sep 16 . 60 Sep 16 .53 .22 166 847 1970 11.4 1977 148 690 1961 13.2 1994 WATER 255 824 31 40000 2 2 118000 26 184800 1 17 487 87 17 249 1677 1979 16.5 1976 YEARS 1960 .5 Oct .7 Apr .9 Apr Jan .39 Jan .28 .35 332 1691 1960 19.2 1991 - 1995 1971 1994 9 1970 17 1984 15 1984 5 1992 5 1992 146 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HWY 2 NR TOA ALTA, PR (National stream-quality accounting network station) WATER-QUALITY RECORDS LOCATION.--Lat 18°24'41", long 66°15'39", at Highway 2, 1.3 mi (2.1 km) downstream from Rio 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 ARBA.--208 mi 1 (539 km 1 ), exclude 8.2 mi 1 (21.2 km] ) upstream from Lago Carite, flow from which is diverted to Rio Guamani. PERIOD OP RECORD.--Water years 1958 to current year WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 11.. . DEC 14... FEB 1995 06.. . APR 06. . . JUN 08.. . SEP 07. .. DATE OCT 1994 11. .. DEC 14... FEB 1995 06. .. APR 06. . . JUN 08. .. SEP 07. . . DATE OCT 1994 11. .. DEC 14. .. FEB 1995 06. . . APR 06. .. JUN 08. .. SEP 07. . . DIS- PH OXYGEN, COLI- CHARGE, SPE- WATER DIS- FORM, STREP- HARD- INST. CIFIC WHOLE SOLVED FECAL, TOCOCCI NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- 0.45 FECAL, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT UM-MF (COLS. (MG/L SOLVED TIME PER ANCE ARD WATER ITY SOLVED SATUR- (COLS./ PER AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) 100 ML) 100 ML) CACO3) AS CA) 1145 1500 1145 0910 1145 12 14 12 12 37 1005 193 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 14 13 15 15 13 7.9 SOLIDS, DIS- SOLVED (TONS PER DAY) 11.4 12.1 11.7 10.6 34.9 118 SODIUM, DIS- SOLVED (MG/L AS NA) 30 28 29 29 50 17 NITRO- GEN, NO2+NO3 DIS- SOLVED (MG/L AS N) <0.050 0.060 <0.050 0.050 <0.050 <0.050 550 561 572 541 522 7.0 7.4 7.3 7.2 7.3 25.0 24.0 23.0 23.5 27.5 LV402 LV7.4 SODIUM AD- SORP- TION RATIO 0.9 0.8 0.8 0.8 1 0.6 NITRO- GEN, AMMONIA DIS- SOLVED (MG/L AS N) 0.220 0.430 0.110 0.100 0.100 0.470 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 5.1 4.3 3.6 2.5 6.1 4.4 NITRO- GEN, AMMONIA DIS- SOLVED (MG/L AS NH4) 0.50 0.55 0.14 0.13 0.11 0.15 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 210 210 230 210 180 LV140 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.18 0.80 0.40 0.50 0.30 0.21 0.60 12 1.1 0.90 3.5 49 SULFATE DIS- SOLVED (MG/L AS SO4) 17 20 17 15 31 22 PHOS- PHORUS TOTAL (MG/L AS P) 0.170 0.190 0.130 0.140 0.180 0.190 0.8 0.6 0.4 0.3 1.7 -- CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 44 39 43 43 52 26 PHOS- PHORUS DIS- SOLVED (MG/L AS P) 0.150 0.140 0.090 0.130 0.170 0.180 9 7 5 4 21 -- FLUO- RIDE, DIS- 2000 K1100 390 410 K1300 26000 SILICA, DIS- SOLVED SOLVED (MG/L (MG/L AS F) 0.20 0.10 0.10 0.10 0.10 <0.10 PHOS- PHORUS ORTHO, DIS- SOLVED (MG/L AS P) 0.120 0.140 0.120 0.120 0.130 0.100 AS SI02) 23 20 23 23 15 15 PHOS- PHATE, ORTHO, DIS- SOLVED (MG/L AS PO4) 0.37 0.43 0.37 0.37 0.41 0.34 350 540 330 630 570 16000 SOLIDS, RESIDUE AT 180 DEG. C DIS- SOLVED (MG/L) 337 328 367 328 352 261 ALUM- INUM, DIS- SOLVED (UG/L AS AL) <10 -- <10 -- 10 20 230 69 230 71 260 80 230 68 230 71 160 50 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 329 323 350 322 347 226 BARIUM, DIS- SOLVED (UG/L AS BA) 91 -- 89 -- 90 68 K = non-ideal count LV = laboratory value 747 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HWY 2 MR TOA ALTA, PR—Continued (National stream-quality accounting network station) WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 11. . . DEC 14. .. FBB 1995 06. .. APR 06. .. JUN 08. .. SEP 07. .. COBALT, IRON, DIS- DIS- SOLVED SOLVED (UG/L (UG/L AS CO) AS FE) <3 17 __ <3 95 __ <3 12 <3 26 LITHIUM DIS- SOLVED (UG/L AS LI) <4 — <4 __ <4 14 MANGA- NESE, DIS- SOLVED (UG/L AS MM) 490 __ 400 __ 310 71 MOLYB- MERCURY DENUM, DIS- DIS- SOLVED SOLVED (UG/L (UG/L AS HG) AS MO) <0.1 <10 __ 0.2 <10 __ <0.1 <10 10 NICKEL, DIS- SOLVED (UG/L AS NI) 1 __ 1 __ 2 3 SELE- NIUM, SILVER, DIS- DIS- SOLVED SOLVED (UG/L (UG/L AS SE) AS AG) •< 1 •<! • 0 __ < 1 < 1 . 0 __ •< 1 < 1 . 0 •< 1 •<! . 0 STRON- VANA- TIUM, DIUM, DIS- DIS- SOLVED SOLVED (UG/L (UG/L AS SR) AS 290 _- 360 __ 260 180 V) <6 _- <6 __ <6 <6 PESTICIDE ANALYSES CHLOR- DANE, P,P'- TECH- ODD P,P DOT '- ENDO- DI- DI- SULFAN, PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I DATE TIME 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) JUN 08 1995 1145 <0 BNDRIN WATER UNFLTRD DATE REC (UG/L) .100 <0. ETHION, TOTAL (UG/L) 010 <0 HEPTA- CHLOR, TOTAL (UG/L) .100 <0.010 <0. HEPTA- CHLOR EPOXIDB LINDANE TOTAL TOTAL (UG/L) (UG/L) 010 <0. MALA- THION, TOTAL (UG/L) 010 0.020 <0. METH- METHYL OXY- PARA- CHLOR, THION, TOTAL TOTAL (UG/L) (UG/L) 010 <0.010 MIREX, TOTAL (UG/L) JUN 1995 08... <0.010 <0.010 <0.010 <0.010 <0.010 0.010 <0.010 <0.010 <0.010 2,4,5-T 2, 4-DP SILVEX, TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) <0.010 <0.010 <0.010 DATE JON 1995 08.. . PARA- THION, TOTAL (UG/L) <0.010 PCNS UNFILT RECOVER (UG/L) <0.100 PER- THANE TOTAL (UG/L) <0.100 TOX- APHENE, TOTAL (UG/L) <1.00 TOTAL TRI- THION (UG/L) <0.010 2,4-D, TOTAL (UG/L) <0.010 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DATE OCT 1994 11... DEC 14.. . PEB 1995 06. .. APR 06. .. OtJN 08.. . SEP 11.. . TIME 1145 1500 1145 0910 1145 1005 STREAM- FLOW, INSTAN- TANEOUS (CFS) 12 14 12 12 37 193 SEDI- MENT, SUS- PENDED (MG/L) 36 44 53 54 48 55 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 1.2 1.6 1.7 1.7 4.8 28 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 91 78 63 58 60 99 148 THIS PAGE WAS LEFT BLANK INTENTIONALLY TLAN11C ^^V'^-^ x - i "***>=*<'L3ev.-e~^ t /^AM., L . 149 • ' EXPLANATION A 047560 SURFACE-WATER STATION AND NUMBER T 0476 QUALITY-OF-WATER STATION AND NUMBER 047560 DA|LY SED|MENJ STATION AND NUMBER 220 WELL AND WELL NUMBER 047550 LAKE-ELEVATION STATION AND NUMBER Figure 19.--Rio Hondo to Rio Puerto Nuevo basins. 150 RIO HONDO BASIN 50047530 RIO HONDO AT FLOOD CHANNEL NEAR CATANO, PR WATER-QUALITY RECORDS LOCATION.—Lat 18°26'13", long 66°09'36", at Rio Hondo Channel, 800 ft (245 m) below junction with Rfo 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 OP RECORD.—Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE NOV 1994 07. .. DEC 29. .. FEB 1995 23... MAY 09. .. OUN 26. .. SEP 22. .. DATE NOV 1994 07... DEC 29. .. FEB 1995 23... MAY 09. . . OUN 28. . . SEP 22.. . DATE NOV 1994 07. .. DEC 29... FEB 1995 23. .. MAY 09. .. OUN 26. .. SEP 22. .. TIME 1005 0800 0940 0830 0645 0845 HARD- NESS TOTAL (MG/L AS CACO3) 3300 — — 820 — 410 SILICA, DIS- SOLVED (MG/L AS SI02) 7.1 — — 7.6 — 9.6 SPE- CIFIC CON- DUCT- ANCE (US /CM) 50000 27500 28000 8300 17600 2B200 CALCIUM DIS- SOLVED (MG/L AS CA) 230 -- -- 82 -- 48 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 18100 -- — 4800 -- 1920 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.7 8.0 7.3 7.4 8.0 8.3 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 660 -- __ 150 -- 71 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 21 66 15 20 35 96 TEMPER- ATURE WATER (DEG C) 29.0 25.0 26.0 29.0 31.0 28.0 SODIUM, DIS- SOLVED (MG/L AS NA) 5500 -- __ 1600 -- 570 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 1.0 1.2 1.4 1.6 0.97 1.2- TUR- BID- ITY (NTU) 27 9.4 — 8.4 31 61 SODIUM AD- SORP- TION RATIO 42 — — 24 -_ 12 PHOS- PHORUS TOTAL (MG/L AS P) 0.140 0.170 0.270 0.370 0.060 0.200 OXYGEN, DIS- SOLVED (MG/L) 5.5 4.1 4.2 1.4 5.8 3.2 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 210 -- __ 49 -- 24 ARSENIC TOTAL (UG/L AS AS) 1 -- -- 3 -- — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 70 49 51 19 82 44 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 140 160 130 130 110 100 BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) 100 — — <100 — -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 320 710 — 120 230 45 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- 0.6 -- — - BORON, TOTAL RECOV- ERABLE (UG/L AS B) 2600 -- -- 680 -- — COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) K18000 270000 260000 44000 K86000 34000 SULFATE DIS- SOLVED (MG/L AS SO4) 1400 — — 330 — 140 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 — -- <1 — — STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K100 K14000 K1300 380 200000 2000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 10000 -- -- 2500 -- 1000 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 1 -- -- 1 — — FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.70 -- — 0.30 — <0.10 COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) 40 -- — 20 — — K = non-ideal count RIO HONDO BASIN 50047530 RIO HONDO AT FLOOD CHANNEL NEAR CATANO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 151 DATE NOV 1994 07. .. DEC 29. . . FEB 1995 23.. . MAY 09.. . JUN 28.. . SEP 22. . . IRON, TOTAL RECOV- ERABLE (UG/L AS FE) LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) SELE- NIUM, TOTAL (UG/L AS SE) SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) CYANIDE TOTAL (MG/L AS CN) PHENOLS TOTAL (UG/L) METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) 400 550 150 230 <0.10 <0.010 10 <0.010 0.07 0.11 152 RIO DE BAYAMON BASIN 50047550 LAGO CZDRA AT DAHSZTE NEAR CZDRA, PR LOCATION.—Lat 18°11'57", long 66°08'29", Hydrologic Unit 21010005, at Lago de Cidra Dam on Rio de Bayamon, 1.9 mi (3.0 km) northeast of Plaza de Cidra and 1.8 mi (2.9 km) northwest of Escuela Segunda Unidad de Bayamon. DRAINAGE AREA.--8.26 mi 9 (21.39 km9 ). ELEVATION RECORDS PERIOD OP 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 hm5 ) and provides supple- mental 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. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 1,324.14 ft (403.60 m), July 11, 1993; minimum elevation 1,295.86 ft (394.98 m), April 22, 1995. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 1,321.07 ft (402.66 m), Sept. 30; minimum elevation, 1,295.86 ft (394.98 m), April 22. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet 1,295 1,305 1,309 1,312 Contents, in acre-feet 860 1,970 2,610 3,100 Elevation, in feet 1,319 1,322 1,328 Contents, in acre-feet 4,400 5,200 6,920 DAY 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 MAX MIN ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES NOV DEC MAR APR JUN JUL AUG 1 2 3 4 5 6 7 8 9 10 1301.44 1301.42 1301.33 1301.25 1301.17 1301.08 1301.00 1300.91 1300.82 1300.71 1301.89 1301.81 1301.75 1301.69 1301.63 1301.65 1301.66 1301.66 1301.68 1301.59 1300.31 1300.31 1300.29 1300.27 1300.32 1300.48 1300.54 1300.56 1300.56 1300.50 1298.74 1298.64 1298.57 1298.49 1298.43 1298.33 1298.25 1298.15 1298.10 1298.24 1300.59 1300.55 1300.49 1300.40 1300.30 1300.20 1300.10 1300.10 1300.18 1300.21 1302.35 1302.37 1302.29 1302.33 1302.35 1302.30 1302.18 1302.09 1301.99 1301.76 1298.35 1298.38 1298.27 1298.02 1297.78 1297.65 1297.50 1297.33 1297.20 1297.04 1296.50 1296.63 1296.68 1296.80 1296.98 1297.15 1297.38 1297.93 1298.43 1298.62 1296.99 1297.36 1298.40 1298.94 1299.07 1299.01 1298.95 1298.90 1298.85 1298.83 1299.00 1298.87 1298.72 1298.55 1298.35 1298.13 1297.93 1297.71 1297.47 1297.27 A A A A A A A A A 1302.01 1300.63 1300.53 1299.84 1299.75 1299.65 1301.44 1301.30 1301.10 1300.90 1300.72 1300.42 1300.34 1300.25 1300.17 1300.07 1298.44 1298.61 1298.69 1298.80 1298.89 1300.13 1300.03 1299.94 1299.83 1299.76 1301.55 1301.37 1301.41 1301.55 1301.56 1296.98 1297.10 1297.07 1296.89 1296.71 1298.52 1298.40 1298.23 1298.07 1298.60 1298.79 1298.78 1298.74 1298.67 1298.77 1297. 1297. 1297. 1297. 1297. 12 07 08 11 10 1302.00 1301.97 1301.94 1301.98 1302.05 1299.54 1299.52 1299.63 1299.73 1299.80 1300.54 1300.48 1300.43 1300.37 1300.33 1299.98 1299.87 1299.76 1299.66 1299.58 1298.97 1299.04 1299.12 1299.18 1299.25 1299.70 1299.63 1299.57 1299.54 1299.48 1301.40 1301.24 1301.05 1300.56 1300.07 1296. 1296. 1296. 1296. 1296. 50 33 19 13 03 1299.33 1299.21 1299.00 1298.79 1298.43 1298.90 1298.99 1299.07 1299.13 1299.18 1297.00 1296.90 1296.84 1296.84 1296.88 1302.21 1302.33 1302.68 A A 1299.87 1299.95 1300.83 1301.54 1301.95 1300.27 1300.19 1300.16 1300.08 1300.02 1299.50 1299.43 1299.37 1299.29 1299.21 1299.33 1299.41 1299.49 1299.55 1299.63 1299.67 1299.76 1299.91 1299.97 1300.15 1299.61 1299.19 1298.97 1298.90 1298.82 1295.94 1295.86 1296.07 1296.24 1296.31 1298.09 1297.66 1297.35 1297.10 1296.88 1299.25 1299.29 1299.35 1299.42 1299.50 1297.04 1297.36 1297.46 1297.58 1297.65 26 27 28 29 30 31 1302.09 1302.14 1302.21 1302.20 1302.06 1301.96 1299.99 1299.97 1300.07 1300.15 1300.25 ___ 1299.13 1299.05 1299.07 1299.04 1298.95 1298.84 1299.96 1300.13 1300.33 1300.47 1300.55 1300.57 1300.82 1301.62 1302.10 ___ ___ 1298. 1298. 1298. 1298. 1298. 1298. 72 62 52 42 34 32 1296.32 1296.31 1296.27 1296.31 1296.38 1296.68 1296.49 1296.33 1296.26 1296.51 1296.75 1299.59 1299.48 1299.33 1299.23 1299.13 ___ 1298.01 1298.91 A A A A 1302.21 1299.52 1301.89 1299.97 1300.56 1298.84 1300.57 1298.10 1302.10 1299.48 1302.37 1298.32 1298.38 1295.86 1299.33 1296.26 1299.59 1296.99 SEP A A A A A A A A A A A A A A A A A A A A 1319.80 1320.00 1320.17 1320.33 1320.45 1320.51 1320.53 1320.59 1320.85 1321.07 A No gage-height record 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 Plaza de Cidra. DRAINAGE AREA.--8.31 mi 2 (21.5 km 2 ). 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 A<zueduct and Sewer Authority reservoir upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 753 NOV DEC AUG SEP 1 1.7 13 2 1.7 11 3 1.8 10 4 1.8 11 5 1.7 10 6 1.7 11 7 1.8 9.5 8 1.8 9.3 9 1.7 9.3 10 1.8 8.7 11 1.9 7.9 12 1.8 6.4 13 1.8 7.8 14 1.7 8.7 15 1.7 8.0 16 1.8 8.0 17 1.6 7.9 18 2.0 8.6 19 2.1 7.6 20 2.0 8.0 21 1.9 7.9 22 2.9 8.1 23 3.1 7.6 24 1.8 8.5 25 1.6 8.7 26 1.7 8.5 27 1.6 7.9 28 1.5 9.0 29 22 8.3 30 23 9.3 31 19 —— TOTAL 116.0 265.5 MEAN 3.74 8.85 MAX 23 13 MIN 1.5 6.4 AC-FT 230 527 CFSM .45 1.06 IN. .52 1.19 STATISTICS OF MONTHLY MEAN MEAN 12.6 23.7 MAX 20.5 41.2 (WY) 1992 1992 MIN 3.74 8.85 (WY) 1995 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 7.8 7.9 7.9 6.7 4.0 1.4 3.2 3.2 3.8 8.0 11 9.8 8.9 8.6 9.1 10 9.8 9.2 8.4 6.9 6.6 6.6 6.6 6.8 6.6 7.2 6.8 7.2 7.5 7.0 7.2 221.7 7.15 11 1.4 440 .86 .99 6.9 7.7 5.9 5.3 5.5 6.3 5.4 5.4 4.9 4.2 3.1 6.9 5.5 5.7 6.1 6.6 6.5 7.2 6.9 5.9 4.7 4.9 5.6 4.3 4.3 5.3 3.2 2.3 1.9 5.4 9.3 169.1 5.45 9.3 1.9 335 .66 .76 DATA FOR WATER 14.3 30.4 1992 4.36 1994 FOR 19.3 59.6 1992 5.45 1995 9.2 10 11 9.4 9.7 9.7 10 9.6 9.3 9.7 9.7 9.3 9.0 9.1 8.3 8.3 7.9 7.5 7.8 7.3 8.2 5.8 6.3 6.9 6.7 9.1 7.4 6.2 ___ ___ —— 238.4 8.51 11 5.8 473 1.02 1.07 YEARS 1991 17.2 36.5 1991 7.24 1994 1.8 7.1 8.7 2.3 2.1 7.2 13 8.2 9.4 23 22 22 13 1.0 4.9 12 12 15 52 50 41 35 16 5.0 4.4 4.9 5.4 5.2 5.3 5.3 4.8 419.0 13.5 52 1.0 831 1.62 1.87 - 1995 16.2 23.7 1992 11.4 1994 1994 CALENDAR YEAR 2080. 5. 23 1. 1. 4130 . 9. 11 5. 1. 2 70 Oct 30 2 Jul 25 3 Jul 24 68 30 3 5 4.9 4.6 15 21 21 18 15 15 14 13 11 13 12 11 7.5 5.4 3.9 2.5 1.4 1.3 1.2 1.2 1.2 1.2 1.1 1.0 1.0 .97 .96 .90 --- 221.23 7.37 21 .90 439 .89 .99 , BY WATER 12.4 23.0 1992 7.37 1995 FOR 1995 2570 7 52 289 11 5100 11 13 5 1 .93 .85 .84 .76 .71 .70 .80 2.8 .68 2.0 12 12 12 12 17 13 14 14 23 47 46 44 31 21 16 13 9.3 6.5 5.6 8.4 4.9 392.77 12.7 47 .68 779 1.52 1.76 YEAR (WY) 8.96 12.7 1995 4.13 1993 2.1 2.5 2.8 2.2 5.9 12 12 8.1 6.2 6.0 5.9 5.6 5.7 5.8 2.2 2.3 2.2 2.1 2.1 2.1 2.1 2.6 2.1 1.9 2.0 2.1 16 14 5.8 5.5 —— 149.9 5.00 16 1.9 297 .60 .67 10.8 17.8 1992 3.47 1994 WATER YEAR .72 .04 .68 .80 .25 .85 .49 .8 .0 Mar 19 May 9 May 1 Sep 16 Sep 16 5.6 5.2 6.0 5.5 5.3 5.4 5.3 5.3 5.3 4.4 3.0 1.2 1.1 .92 .98 1.1 1.1 1.1 1.0 1.1 1.3 1.1 1.1 1.0 1.0 1.4 1.5 2.1 1.1 1.0 .97 79.47 2.56 6.0 .92 158 .31 .36 15.0 39.6 1993 1.56 1994 WATER 13 24 5 981 2090 16 9660 1 21 27 9 1 1.0 .91 1.3 1.0 .93 1.0 .85 .91 .87 .91 .91 .93 1.1 .95 .98 1.0 1.0 1.7 2.4 1.0 1.1 1.1 1.2 1.2 1.2 1.2 1.2 1.9 1.5 2.0 1.4 36.65 1.18 2.4 .85 73 .14 .16 11.5 27.5 1991 1.18 1995 YEARS 1991 .3 .7 .93 Jan .60 Aug .80 May Jul .56 Jul .60 .77 .9 .8 1.5 1.4 1.5 1.4 2.0 10 6.8 2.3 2.2 3.7 13 13 13 14 17 26 11 8.3 9.3 8.8 9.4 8.5 8.6 8.5 8.3 8.9 11 9.0 14 8.6 ___ 261.0 8.70 26 1.4 518 1.05 1.17 10.4 16.0 1991 1.64 1994 - 1995 1992 1994 6 1992 6 1992 1 1995 11 1993 11 1993 154 RIO DK BAYAHON BASIN 50047560 RIO DE BAYAMON BRLOW LAGO CIDRA , PR—Continued WATER- QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1991 to current year. PERIOD OF DAILY RECORD. -- SUSPENDED- SEDIMENT DISCHARGES November 1990 to September 1995. INSTRUMENTATION.-- Automatic sediment sampler since 1990. REMARKS. — Sediment samples were collected by a local observer on a weekly basis and during high Clow events. EXTREMES FOR PERIOD OF DAILY RECORD. -- SEDIMENT CONCENTRATION: Maximum daily mean, 3,670 mg/L Jan. 05, 1992; Minimum daily mean, 3 mg/L November 27, 1993. SEDIMENT LOADS: Maximum daily mean, 9,B30tons (8, 920tonnes) Jan. 05, 1992; Minimum daily mean, 0.02 ton (0.02 tonne) November 21, 1993. EXTREMES FOR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATION: Maximum daily mean, 166 mg/L May 15, 1995; Minimum daily mean, 5 mg/L August 07,06,09, 1995. SEDIMENT LOADS: Maximum daily mean, 37 tons (32 tonnes) May 15, 1995; Minimum daily mean, 0.01 ton (0.01 tonne) May 04,06, 1995. SEDIMENT DISCHARGE, SUSPENDED ( TONS / DAY ), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 6 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 26 29 30 31 1.7 1.7 1.6 1.6 1.7 1.7 1.6 1.6 1.7 1.6 1.9 1.6 1.6 1.7 1.7 1.6 1.6 2.0 2.1 2.0 1.9 2.9 3.1 1.6 1.6 1.7 1.6 1.5 22 23 19 OCTOBER 26 19 14 14 15 17 20 24 34 26 25 22 25 26 27 27 26 26 26 25 25 26 26 24 24 24 23 22 22 22 23 NOVEMBER DECEMBER .12 .09 .07 .07 .07 .06 .10 .12 .16 .14 .13 .11 .12 .12 .13 .13 .12 .14 .14 .14 .13 .23 .24 .12 .11 .12 .11 .09 1.4 1.3 1.2 13 11 10 11 10 11 9.5 9.3 9.3 6.7 7.9 6.4 7.8 6.7 6.0 6.0 7.9 6.6 7.6 6.0 7.9 6.1 7.6 6.5 6.7 6.5 7.9 9.0 6.3 9.3 21 20 20 21 20 22 20 20 21 20 21 21 22 25 25 25 24 23 19 23 26 25 24 24 20 17 16 17 16 17 .76 .62 .56 .62 .57 .67 .53 .52 .53 .49 .44 .36 .46 .59 .54 .54 .52 .56 .39 .50 .55 .56 .50 .55 .49 .40 .36 .46 .43 .46 7.6 7.9 7.9 6.7 4.0 1.4 3.2 3.2 3.6 6.0 11 9.6 6.9 6.6 9.1 10 9.6 9.2 6.4 6.9 6.6 6.6 6.6 6.6 6.6 7.2 6.6 7.2 7.5 7.0 7.2 17 17 17 17 17 14 13 13 16 20 21 26 43 60 39 21 13 11 6 10 11 16 23 16 16 16 21 35 61 56 41 .37 .37 .37 .33 .19 .06 .12 .12 .16 .47 .63 .76 1.0 1.4 .96 .56 .35 .29 .19 .21 .20 .33 .43 .34 .30 .35 .40 .69 1.2 1.1 .76 116.0 7.37 265.5 15.57 221.7 15.07 RIO DE BAYAMON BASIN 155 50047560 RIO DE BAYAMON BELOW LAGO CIDRA , PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 6 7 5 5 5 6 5 5 4 4 3 6 5 5 6 6 6 7 6 5 4 4 5 4 4 5 3 2 1 5 9 .9 .7 .9 .3 .5 .3 .4 .4 .9 .2 .1 .9 .5 .7 .1 .6 .5 .2 .9 .9 .7 .9 .6 .3 .3 .3 .2 .3 .9 .4 .3 30 26 20 22 18 16 16 12 13 15 15 20 22 28 30 32 33 34 35 37 38 39 40 42 43 44 46 47 47 30 20 .57 .57 .34 .34 .29 .30 .26 .21 .20 .18 .14 .40 .35 .44 .51 .58 .58 .67 .66 .59 .49 .53 .60 .48 .50 .64 .39 .29 .24 .42 .54 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) FEBRUARY 9.2 10 11 9.4 9.7 9.7 10 9.6 9.3 9.7 9.7 9.3 9.0 9.1 8.3 8.3 7.9 7.5 7.8 7.3 8.2 5.8 6.3 6.9 6.7 9.1 7.4 6.2 ___ ___ 14 20 18 12 17 19 25 22 20 18 18 18 18 18 20 21 21 20 21 22 24 24 27 26 27 28 28 32 -__ -__ ___ .38 .62 .59 .32 .50 .53 .71 .59 .53 .50 .50 .48 .46 .44 .46 .49 .46 .42 .45 .45 .55 .39 .47 .49 .50 .74 .56 .51 ___ ___ 1. 7. 8. 2. 2. 7. 13 8. 9. 23 22 22 13 1. 4. 12 12 15 52 50 41 35 16 5. 4. 4. 5. 5. 5. 5. 4. MARCH 8 1 7 3 1 2 2 4 0 9 0 4 9 4 2 3 3 8 70 149 94 42 23 26 34 38 47 43 35 30 31 33 36 39 42 43 31 21 15 17 19 22 23 23 22 22 21 21 21 .35 3.0 2.3 .26 .13 .59 1.2 .85 1.2 2.6 2.1 1.8 1.1 .09 .48 1.3 1.4 1.7 4.4 2.9 1.7 1.6 .77 .31 .28 .31 .33 .32 .31 .31 .28 TOTAL 169.1 13.30 238.4 14.09 419.0 36.27 156 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA , PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 JAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MEAN DISCHARGE (CFS) 4.9 4.6 15 21 21 18 15 15 14 13 11 13 12 11 7.5 5.4 3.9 2.5 1.4 1.3 1.2 1.2 1.2 1.2 1.1 1.0 1.0 .97 .96 .90 ___ MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) APRIL 19 20 19 19 19 19 18 18 17 17 17 18 16 18 16 17 16 17 15 15 12 13 13 12 10 10 10 9 9 9 .27 .26 .81 1.1 1.1 .89 .77 .75 .67 .63 .54 .64 .56 .56 .34 .26 .18 .12 .06 .05 .04 .05 .05 .04 .03 .03 .03 .02 .03 .02 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MEAN DISCHARGE (CFS) MAY 2 2 12 12 12 12 17 13 14 14 23 47 46 44 31 21 16 13 9 6 5 8 4 .93 .85 .64 .76 .71 .70 .80 .8 .66 .0 .3 .5 .6 .4 .9 8 8 8 6 7 6 7 32 37 39 41 34 29 23 168 34 26 20 15 15 14 12 13 19 12 15 15 17 18 20 21 .02 .02 .02 .01 .02 .01 .02 .55 .07 .22 1.4 1.1 .93 .76 37 1.2 .99 .78 .92 2.0 1.7 1.4 1.1 1.1 .54 .55 .39 .32 .29 .50 .28 2. 2. 2. 2. 5. 12 12 8. 6. 6. 5. 5. 5. 5. 2. 2. 2. 2. 2. 2. 2. 2. 2. 1. 2. 2. 16 14 5. 5. -- 1 5 8 2 9 1 2 0 9 6 7 8 2 3 2 1 1 1 1 6 1 9 0 1 8 5 - MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) JUNE 2, 2, 2, 2. 5. 12 12 8. 6. 6. 5. 5. 5. 5. 2. 2. 2. 2. 2. 2. 2. 2. 2. 1. 2. 2. 16 14 5. 5. .1 ,5 ,8 ,2 .9 1 2 ,0 ,9 ,6 ,7 8 2 ,3 2 .1 ,1 ,1 1 6 1 9 0 ,1 8 5 22 24 29 33 43 64 98 137 76 32 16 13 11 10 12 12 13 16 18 19 20 22 25 31 42 56 75 101 127 56 .13 .17 .22 .20 .72 2.0 3.0 2.9 1.2 .51 .26 .21 .19 .17 .08 .08 .09 .09 .11 . 12 .12 .16 .15 .16 .22 .32 3.5 3.6 2.0 .81 221.23 10.90 392.77 56.21 149.9 23.49 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA , PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 5.6 19 .30 1.0 8 .03 1.5 75 .31 2 5.2 15 .22 .91 7 .02 1.4 77 .28 3 6.0 17 .29 1.3 10 .06 1.5 76 .30 4 5.5 17 .27 1.0 8 .03 1.4 75 .29 5 5.3 16 .25 .93 6 .02 2.0 74 .41 6 5.4 16 .25 1.0 6 .03 10 74 2.0 7 5.3 16 .24 .85 5 .02 6.8 73 1.3 8 5.3 16 .24 .91 5 .02 2.3 72 .44 9 5.3 16 .24 .87 5 .02 2.2 71 .42 10 4.4 16 .21 .91 6 .02 3.7 71 .73 11 3.0 17 .15 .91 6 .02 13 77 2.7 12 1.2 20 .07 .93 7 .02 13 88 3.1 13 1.1 19 .06 1.1 9 .04 13 99 3.6 14 .92 20 .05 .95 11 .03 14 112 4.2 15 .98 20 .06 .98 12 .04 17 115 5.3 16 1.1 21 .06 1.0 15 .05 26 136 20 17 1.1 22 .07 1.0 19 .05 11 116 3.3 18 1.1 37 .13 1.7 21 .12 8.3 116 2.6 19 1.0 17 .05 2.4 22 .18 9.3 116 2.9 20 1.1 12 .04 1.0 25 .07 8.8 117 2.8 21 1.3 8 .04 1.1 29 .09 9.4 117 3.0 22 1.1 9 .03 1.1 33 .10 8.5 118 2.7 23 1.1 9 .03 1.2 51 .22 8.6 123 2.9 24 1.0 8 .03 1.2 54 .17 8.5 130 3.0 25 1.0 8 .03 '1.2 60 .20 8.3 135 3.0 26 1.4 9 .05 1.2 66 .22 8.9 121 2.9 27 1.5 10 .05 1.2 69 .22 11 104 3.0 28 2.1 9 .11 1.9 70 .36 9.0 90 2.2 29 1.1 8 .03 1.5 71 .29 14 94 5.3 30 1.0 8 .03 2.0 73 .40 8.6 80 1.9 31 .97 8 .02 1.4 74 .28 --- --- --- TOTAL 79.47 --- 3.70 36.65 --- 3.44 261.0 --- 86.88 YEAR 2570.72 286.29 158 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA, PR--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DATE MAY 1995 15. .. DIS- CHARGE, INST. CUBIC FEET PER SECOND SEDI- MENT, SUS- PENDED (MG/L) SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) SED. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM SED. SUSP. FALL DIAM. PERCENT FINER THAN . 008 MM 1515 130 10900 3825 43 53 65 DATE MAY 1995 15. .. SED. SUSP. FALL DIAM. PERCENT FINER THAN 016 MM SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 79 86 97 98.9 99.3 99.5 99.7 159 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA, PR--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DATE NOV 1994 03.. . MAY 1995 15... AUG 02.. . SEP 25... TIME 1702 1530 1542 1618 STREAM- PLOW, INSTAN- TANEOUS (CPS) 10 102 0.84 8 SEDI- MENT, SUS- PENDED (MG/L) 19 5570 1300 138 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 0.51 1530 2.9 2.9 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 54 99 80 95 160 RIO DE BAYAHON BASIN 50047600 RIO DE BAYAHON 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 Aguae Buenos plaza DRAINAGE AREA.--18.5 mi' (47.9 km'). PERIOD OF RECORD.--Water years 1958-65, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 12. .. DEC 05. .. FEB 1995 07. . . APR 11... JUN 07. .. AUG 02. . . DATE OCT 1994 12. .. DEC 05. .. FEB 1995 07. .. APR 11. .. JUN 07. . . AUG 02. .. DATE OCT 1994 12. .. DEC 05. .. FEB 1995 07. .. APR 11. . . JUN 07. . . AUG 02. .. TIME 0915 1555 1200 1305 1030 1120 HARD- NESS TOTAL (MG/L AS CAC03) 150 -- -- 110 __ 160 SILICA, DIS- SOLVED (MG/L AS SIO2) 31 -- -- 26 — 32 DIS- CHARGE, INST. CUBIC FEET PER SECOND 5.5 14 12 14 13 5.0 CALCIUM DIS- SOLVED (MG/L AS CA) 35 -- -- 25 -- 38 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 222 -- -- 175 -- 233 SPE- CIFIC CON- DUCT- ANCE (US/CM) 339 343 289 283 310 358 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 15 — -- 11 __ 15 SOLIDS, DIS- SOLVED (TONS PER DAY) 3.29 -- -- 6.66 -- 3.16 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.B 7.8 8.0 7.7 7.8 8.0 SODIUM, DIS- SOLVED (MG/L AS NA) 20 -- __ 17 __ 18 RESIDUE TOTAL AT 105 DBG. C, SUS- PENDED (MG/L) 13 4 1 4 1 11 TEMPER- ATURE WATER (DEG C) 22.0 23.0 21.5 24.5 25.0 26.0 SODIUM AD- SORP- TION RATIO 0.7 — __ 0.7 __ 0.6 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 0.20 <0.20 0.20 0.30 0.32 TUR- BID- ITY (NTU) 0.50 16 1.7 2.0 3.4 5.0 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 1.6 __ __ 2.1 __ 2.7 PHOS- PHORUS TOTAL (MG/L AS P) 0.030 0.050 0.040 0.040 0.060 0.020 OXYGEN, DIS- SOLVED (MG/L) 6.3 6.7 8.5 7.6 7.8 7.4 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 130 110 110 100 100 140 ARSENIC TOTAL (UG/L AS AS) 1 -- — <1 — — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 72 79 98 95 97 94 SULFIDE TOTAL (MG/L AS S) <0.5 -- __ <0.5 __ ~~ BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 11 10 <10 29 10 <10 SULFATE DIS- SOLVED (MG/L AS SO4) 21 — — 14 __ 19 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 30 — — 30 — — COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 250 2400 K690 420 410 490 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 20 -- __ 20 __ 24 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 450 2000 990 K1300 500 880 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 -- — <0.10 __ <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 -- -- K = non-ideal count RIO DE BAYAMON BASIN 50047600 RIO DE BAYAMON NEAR AGUAS BUENAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 161 DATE OCT 1994 12. .. DEC 05. .. FEB 1995 07. .. APR 11. .. JUN 07. .. AUG 02. .. COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS FE) AS PB) AS MM) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) 20 <0.10 <0.10 <0.010 <0.010 (MG/L) 0.02 <0.02 162 RIO DE BAYAMON BASIN 50047650 RIO BAYAMON NR BAYAMON, PR LOCATION.--Lat lB°20'OB n , long 66°08'13", Hydrologic Unit 21010005, on left bank, at rook quarry near Highway 174, 1.3 mi (2.1 km) south of colonia Santa Rosa and 4.7 mi (7.6 km) south of Bayamon. DRAINAGE AREA.--41.B mi 1 (106.3 km1 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--September 1964 to October 1970, June 19BB to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 96 ft (30 m), from topografic map. REMARKS.--Records fair. 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES NOV DEC JAN MAR MAY AUG 1 4.7 5.6 2 4.4 5.6 3 4.1 5.6 4 4.2 6.2 5 3.6 6.2 6 3.6 5.6 7 26 5.6 6 17 15 9 7.1 16 10 5.6 6.6 11 5.2 7.5 12 .6 6.1 13 .2 5.6 14 .3 5.5 15 .4 5.5 16 .1 5.3 17 .5 5.2 16 7.1 4.9 19 7.4 5.6 20 10 7.4 21 7.7 7.8 22 33 6.6 23 66 5.9 24 24 5.4 25 9.1 5.7 26 7.2 6.3 27 6.7 7.6 26 6.2 11 29 6.1 17 30 6.0 42 31 6.0 TOTAL 336.5 256.9 MEAN 10.9 6.56 MAX 66 42 MIN 3.6 4.9 AC-FT 667 510 CFSM .26 .20 IN. .30 .23 44 12 16 30 33 9.4 7.1 6.7 6.0 5.7 5.7 5.5 5.5 5.4 5.3 5.6 5.1 5.2 5.1 4.6 .6 .7 .5 .3 .5 .4 .5 5.5 4.9 5.2 5.1 277.5 6.95 44 4.3 550 .21 .25 STATISTICS OF MONTHLY MEAN DATA MEAN 31.6 45.4 MAX 129 174 (WY) 1991 1970 MIN 4.30 7.91 (WY) 1969 1965 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 43.4 263 1966 5.19 1966 FOR 5.3 5.2 5.3 5.6 4.6 5.0 5.0 5.2 6.5 7.5 6.5 12 6.5 7.2 6.3 6.4 6.4 6.4 6.2 15 9.2 9.9 9.4 10 10 56 19 22 11 6.9 6.1 313.6 10.1 56 4.8 622 .24 .26 7.5 6.6 €.2 5.9 5.6 5.7 5.5 5.6 5.6 5.6 5.5 5.3 5.2 5.0 5.0 6.0 6.5 6.5 25 19 17 14 6.9 11 40 94 70 131 ___ —— 535.3 19.1 131 5.0 1060 .46 .46 FOR WATER YEARS 1964 34.6 159 1969 5.30 1966 21.6 75.3 1989 4.75 1965 57 21 44 33 39 47 17 11 6.6 6.6 6.2 9.3 35 34 14 9.5 6.4 7.6 7.0 6.4 6.6 6.7 6.2 6.1 5.7 5.0 4.9 5.5 5.5 4.6 5.0 467.6 15.7 57 4.6 967 .36 .43 - 1995 18.4 52.9 1990 3.56 1965 1994 CALENDAR YEAR 2904.0 7.96 66 2.6 2.7 5760 .19 2.56 14 5.6 3.4 Oct 23 Jul 12 Jul 11 4.9 4.5 4.3 6.4 6.9 7.0 6.6 6.7 6.6 5.6 10 10 7.1 6.2 6.9 12 6.6 5.4 5.1 4.2 4.0 4.0 3.6 4.2 3.6 3.6 3.4 3.6 3.2 3.5 —— 169.7 5.66 12 3.2 337 .14 .15 2.6 3.2 3.2 3.3 3.5 5.6 6.6 16 24 6.6 6.7 5.2 4.7 3.9 6.0 15 6.2 7.5 5.6 6.3 4.5 3.9 3.9 .0 .2 .7 .2 .5 .5 5.6 5.2 199.1 6.42 24 2.6 395 .15 .18 4.1 6.1 66 19 12 11 10 9.2 9.3 9.2 9.2 6.2 6.4 7.5 7.0 10 10 9.5 10 13 14 13 12 11 11 10 27 31 17 15 --- 411.7 13.7 66 4.1 617 .33 .37 14 14 13 25 26 26 19 15 14 12 15 24 17 16 17 13 12 12 12 12 69 31 27 23 23 21 45 69 117 37 26 616 26.4 117 12 1620 .63 .73 23 94 159 42 27 26 21 20 17 17 17 16 15 65 46 31 32 160 396 136 29 162 120 139 63 26 20 17 16 33 57 2066 66.7 396 15 4100 1.60 1.64 31 43 24 16 36 623 162 106 36 33 36 63 45 42 64 741 111 42 16 15 15 14 14 14 13 13 13 16 17 14 --- 2656 66.5 623 13 5270 2.12 2.36 , BY WATER YEAR (WY) 21.9 72.7 1971 5.36 1965 FOR 1995 6530. 23. 623 2. 3. 4190 11. 16920 7. 42 6. 4. 43.6 131 1966 4.85 1994 WATER YEAR 1 4 Sep 6 6 May 1 2 Apr 29 Sep 6 63 Sep 6 56 59 4 5 19.9 60.6 1970 3.66 1994 22.2 46.6 1970 4.01 1994 WATER 32 59 10 5500 2 2 26000 20 23360 10 57 13 4 42.6 137 1970 7.47 1994 YEARS 1964 - .3 .7 .9 Oct 9 .2 Apr 19 .4 Apr 14 Get 9 .20 Oct 9 .77 .49 .7 43.3 146 1969 6.02 1967 1995 1966 1994 1970 1965 1965 1970 1970 163 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 Rio de Bayamdn, and 2.3 mi (3.7 km) southeast of Bayamon plaza. DRAINAGE AREA.--73.2 mi 1 (189.6 km 1 ). PERIOD OP RECORD.--Hater years 1958, 1964, 1971-73, 1976, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 05. .. DEC 05. . . FEB 1995 03. . . APR 05. . . JUN 05. . . AU6 02. . . DATE OCT 1994 05... DEC 05... FEB 1995 03. . . APR 05. . . JTJN 05. . . AU6 02... DATE OCT 1994 05. .. DEC 05. .. FEB 1995 03. .. APR 05. .. JUN 05. .. AU6 02. . . TIME 1035 0825 0725 0715 0950 0745 HARD- NESS TOTAL (MG/L AS CACO3) 210 — — 200 -- 80 SILICA, DIS- SOLVED (MG/L AS SIO2) 33 __ __ 33 -- 39 DIS- CHARGE, INST. CUBIC FEET PER SECOND * * * * * * CALCIUM DIS- SOLVED (MG/L AS CA) 57 -_ __ 48 __ 19 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 317 -- -- 390 -- 213 SPE- CIFIC CON- DUCT- ANCE (US/CM) 470 425 500 510 490 490 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 16 — — 20 — 7.8 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 14 27 12 21 53 5 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.4 7.2 7.3 7.1 7.8 7.2 SODIUM, DIS- SOLVED (MG/L AS NA) 35 __ __ 87 __ 20 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.50 0.50 0.50 0.40 1.0 1.0 TEMPER- ATURE WATER (DEG C) 28.0 25.0 24.0 25.0 27.0 27.0 SODIUM AD- SORP- TION RATIO 1 __ — 3 __ 1 PHOS- PHORUS TOTAL (MG/L AS P) 0.280 0.200 0.210 0.220 0.170 0.230 TUR- BID- ITY (NTU) 0.70 23 11 8.2 4.7 3.1 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 3.7 __ __ 6.1 __ 1.9 ARSENIC TOTAL (UG/L AS AS) 3 __ __ -- __ -- OXYGEN, DIS- SOLVED (MG/L) 3.0 3.6 2.2 2.6 1.2 1.6 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CACO3 190 160 160 200 200 160 BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) 200 -- -- <100 — — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 38 43 26 31 15 20 SULFIDE TOTAL (MG/L AS S) <0.5 _- _- <0.5 -- — — BORON, TOTAL RECOV- ERABLE (UG/L AS B) 60 -- -- 50 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 11 14 15 10 16 <10 SULFATE DIS- SOLVED (MG/L AS SO4) 17 __ — 16 __ 8.9 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 __ -- <1 -- — COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) K9200 K190000 23000 4100 K19000 K72000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 41 -- __ 60 -- 20 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 790 4300 K1800 910 K1800 7100 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.20 — — 0.20 — 0.10 COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 -- -- 10 — — * = Discharge measurement values not available due to ponded conditions. K = non-ideal count 164 RIO DE BAYAMON BASIN 50047990 RIO GUAYNABO NEAR BAYAMON, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 OCT 1994 05.. . DEC 05.. . FEB 1995 03.. . APR 05... JUN 05.. . AUG 02.. . IRON, TOTAL RECOV- ERABLE (UG/L AS FE) 400 LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) <1 MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 320 MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 SELE- NIUM, TOTAL (UG/L AS SE) <1 SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <1 ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) <10 CYANIDE TOTAL (MG/L AS CN) •cO.010 PHENOLS TOTAL (UG/L) <! METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L} 0.07 670 350 <0.10 <1 30 <0.010 <1 0.08 165 RIO DE BAYAMON BASIN 50048510 RIO DE BAYAMON AT FLOOD CHANNEL AT BAYAMON, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'29 H , long 66°09'04 H , at bridge on Highway 890, 1.0 nd (1.6 km) downstream from bridge on High- way 2, and 3.2 mi (5.1 km) above mouth. DRAINAGE AREA.--71.9 mi' (186.2km 1 ). PERIOD OP RECORD.—Hater 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. HATER-QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 05. . . DEC 05. .. FEB 1995 03. .. APR 05. . . JtJN 05. .. AUG 02. .. DATE OCT 1994 05. .. DEC 05. .. FEB 1995 03. .. APR 05. .. JUN 05. .. AUG 02. .. TIME 0720 0945 0855 0945 1125 0930 HARD- NESS TOTAL (MG/L AS CACO3) 210 -- -- 180 -- 170 SILICA, DATE OCT 1994 05. .. DEC 05. .. FEB 1995 03. .. APR 05. . . JtJN 05. .. AUG 02. .. K = non-ideal DIS- SOLVED (MG/L AS SI02) 31 -- -- 25 -- 29 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 2.7 107 4.4 4.9 18 9.0 CALCIUM DIS- SOLVED (MG/L AS CA) 55 -- -- 47 -- 47 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 306 -- -- 312 -- 278 SPE- CIFIC CON- DUCT- ANCE (US /CM) 470 305 480 465 437 470 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 18 -- — 15 — 13 SOLIDS, DIS- SOLVED (TONS PER DAY) 2.24 -- — 4.16 — 6.74 PH HATER WHOLE FIELD (STAND- ARD UNITS) 7.2 7.1 7.0 7.1 7.5 7.2 SODIUM, DIS- SOLVED (MG/L AS NA) 29 _- -- 33 -- 30 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 9 62 18 20 15 14 TEMPER- ATURE HATER (DEG C) 28.0 25.0 25.0 28.5 27.0 29.0 SODIUM AD- SORP- TION RATIO 0.9 — -- 1 _- 1 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.40 0.50 2.0 4.3 0.85 0.80 TUR- BID- ITY (NTU) 1.9 62 3.9 3.7 32 9.0 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.6 __ -- 3.7 -- 3.6 PHOS- PHORUS TOTAL (MG/L AS P) 0.090 0.140 0.230 0.770 0.150 0.070 OXYGEN, DIS- SOLVED (MG/L) 3.8 5.0 1.4 2.4 5.0 2.6 ALKA- LINITY HAT WH TOT FET FIELD MG/L AS CACO3 200 110 170 220 180 170 ARSENIC TOTAL (UG/L AS AS) 2 -- — 2 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 48 59 17 31 62 34 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 -- — — BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 11 14 21 54 16 <10 SULFATE DIS- SOLVED (MG/L AS S04) 16 -- — 15 — 14 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 40 -- -- 70 -- -- COLI- FORM, FECAL, 0.45 UM-MP (COLS./ 100 ML) K690 520000 41000 460000 25000 K60000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 34 -- -- 41 -- 39 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K190 7600 810 27000 K1000 2700 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 -- — 0.10 — 0.20 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 — -- <1 -- — 166 RIO DE BAYAMON BASIN 50048510 RIO DE BAYAMON AT FLOOD CHANNEL AT BAYAMON, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 05. .. DEC 05. .. FEB 1995 03... APR 05. .. JUN 05. .. AUG 02. .. COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 __ -- 10 -- -- IRON, TOTAL RECOV- ERABLE (UG/L AS FE) 450 __ -- 1300 -- -- LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) <1 __ -_ 3 -_ __ MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 420 __ __ 1500 __ __ MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 __ -- <0.10 __ __ SELE- NIUM, TOTAL (UG/L AS SE) <1 __ _- <1 _- _- SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <1 __ -- <1 -- __ ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) <10 __ -- 30 -- -- CYANIDE TOTAL PHENOLS (MG/L TOTAL AS CN) (UG/L) <0.010 <1 __ __ <0.010 2 __ __ METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) 0.06 __ -- 1.9 -- -- PESTICIDE ANALYSES CHLOR- DANE, P,P'- P,P'- ENDO- TECH- ODD DOT DI- DI- SULFAN, PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I DATE TIME 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) JUN 1995 05... 1125 <0 ENDRIN WATER UNFLTRD DATE REC (UG/L) JUN 1995 05... <0.010 PARA- THION, DATE TOTAL (UG/L) JUN 1995 05... <0.010 .100 <0. ETHION, TOTAL (UG/L) <0.010 PCNS UNFILT RECOVER (UG/L) <0.100 ,010 <0 HEPTA- CHLOR, TOTAL (UG/L) <0.010 PER- THANE TOTAL (UG/L) <0.100 .100 <0, HEPTA- CHLOR EPOXIDE TOTAL (UG/L) <0.010 TOX- APHENE, TOTAL (UG/L) <1.00 .010 <0. LINDANE TOTAL (UG/L) <0.010 TOTAL TRI- THION (UG/L) <0.010 .010 <0. MALA- THION, TOTAL (UG/L) 0.010 2,4-D, TOTAL (UG/L) 0.170 .010 0, METH- OXY- CHLOR, TOTAL (UG/L) <0.010 2,4,5-T TOTAL (UG/L) <0.010 .040 <0. METHYL PARA- THION, TOTAL (UG/L) <0.010 2, 4-DP TOTAL (UG/L) <0.010 ,010 <0.010 MIREX , TOTAL (UG/L) <0.010 SILVEX, TOTAL (UQ/L) <0.010 RIO PUERTO NUEVO BASIN 50046770 RIO PIEDRAS AT EL SENORIAL, PR LOCATION.--Lat ie°21'51", long 66°03'56", Hydrologic Unit 21010005, on right bank, in the Riberas of Sefiorial Housing area, 0.6 mi (1.0 km) west of Highway 176 and 2.7 mi (4.3 km) southwest of Rio Piedras Plaza. DRAINAGE AREA.--7.49 mi 1 (19.40 km 1 ). 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 wastes water discharge 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 167 DEC SEP 1 2.7 35 2 2.4 5.5 3 2.5 4.8 4 2.3 5.5 5 2.5 5.1 6 2.4 4.7 7 3.1 4.5 8 45 21 9 30 40 10 3.7 59 11 2.9 8.5 12 2.7 5.5 13 2.7 4.9 14 2.5 4.6 15 2.6 4.5 16 2.3 4.4 17 3.2 4.5 18 9.8 4.1 19 4.8 78 20 12 6.2 21 3.7 4.8 22 47 4.7 23 60 5.1 24 21 5.5 25 8.6 25 26 6.4 19 27 5.3 51 28 4.7 15 29 5.1 51 30 5.0 49 31 4.5 —— TOTAL 313.4 540.4 MEAN 10.1 18.0 MAX 60 78 MIN 2.3 4.1 AC-FT 622 1070 CFSM 1.35 2.40 IN. 1.56 2.68 36 94 26 12 12 12 8.7 6.9 6.1 10 6.1 5.6 5.7 5.0 5.4 4.4 5.6 4.3 4.3 4.9 4.7 5.9 5.3 5.8 4.2 5.3 8.9 4.8 3.9 4.9 3.5 332.2 10.7 94 3.5 659 1.43 1.65 6.6 4.1 8.5 3.0 2.9 4.0 2.8 4.3 7.1 e!4 2.9 33 3.1 3.0 2.0 2.6 1.7 2.2 12 2.0 2.2 1.6 1.5 1.6 1.5 41 e!2 e!9 e4.8 e4.6 e3.9 215.5 6.95 41 1.5 427 .93 1.07 STATISTICS OF MONTHLY MEAN DATA FOR WATER MEAN 24.2 22.9 MAX 57.3 59.8 (WY) 1991 1993 MIN 8.48 7.51 (WY) 1992 1991 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 15.5 40.5 1993 7.29 1994 FOR 14.5 24.4 1992 6.95 1995 e3.8 e2.5 e2.8 e3.1 e2.6 e2.5 e3.1 e2.1 el. 9 el. 6 e9.7 e2.0 e2.1 e2.0 el. 9 2.3 2.7 4.6 87 12 25 3.6 44 3.6 180 36 30 182 ___ ___ --- 656.5 23.4 182 1.6 1300 3.13 3.26 YEARS 1988 13.5 23.6 1991 4.66 1994 129 19 257 22 11 9.0 7.9 9.0 7.1 5.8 6.5 6.2 19 14 5.9 4.2 3.8 4.5 4.3 4.4 8.0 3.8 3.8 3.5 3.5 3.3 3.9 3.7 3.1 3.0 2.9 592.1 19.1 257 2.9 1170 2.55 2.94 - 1995 12.0 19.5 1990 3.65 1994 1994 CALENDAR YEAR 2899. 7. 133 1. 1. 5750 1. 14. 12 4. 2. 7 94 Aug 28 8 Jun 22 9 Jun 18 06 40 0 3 2.9 2.8 2.8 2.4 2.2 2.2 3.1 2.5 2.5 6.6 2.1 3.7 1.7 1.6 15 3.8 2.2 1.8 1.9 2.2 2.4 2.3 1.9 1.8 1.7 1.7 1.7 1.8 1.8 1.8 --- 84.9 2.83 15 1.6 168 .38 .42 1.9 1.9 1.9 2.0 3.6 12 3.8 3.2 3.0 2.6 2.5 2.6 2.7 3.3 32 2.8 1.9 1.7 1.7 2.0 1.5 1.5 1.4 1.5 1.9 2.1 1.6 3.2 2.2 7.3 3.8 117.1 3.78 32 1.4 232 .50 .58 31 14 26 3.6 31 2.4 1.7 4.7 4.0 41 3.1 1.9 1.6 1.3 25 50 1.9 1.3 1.5 6.6 2.1 1.8 1.8 1.7 1.7 2.1 1.8 1.9 1.7 1.5 —— 271.7 9.06 50 1.3 539 1.21 1.35 1.4 1.3 4.8 16 21 27 2.3 2.2 2.1 2.0 4.5 2.6 2.6 18 2.4 1.6 1.5 1.5 1.5 1.6 59 10 15 5.0 2.0 1.9 30 30 5.6 2.0 1.8 280.2 9.04 59 1.3 556 1.21 1.39 1.6 1.4 7.3 1.3 1.5 20 1.3 1.4 1.5 1.1 .99 .91 .84 6.3 1.2 1.0 3.4 48 25 2.3 2.6 1.2 8.2 6.3 1.9 1.3 2.2 1.0 .97 14 152 320.01 10.3 152 .84 635 1.38 1.59 7.6 3.1 2.5 2.7 9.4 321 15 4.4 2.5 2.2 41 45 4.0 1.8 32 176 11 2.9 1.8 21 34 3.0 2.3 1.7 1.4 1.2 2.1 7.0 28 2.3 789.9 26.3 321 1.2 1570 3.52 3.92 , BY WATER YEAR (WY) 13.0 23.9 1993 2.83 1995 FOR 1995 4513. 12. 321 1. 2960 12. 8950 1. 22. 30 3. 1. 16.5 47.2 1992 3.38 1994 WATER YEAR 91 4 Sep 6 84 Aug 13 1 Aug 7 Sep 6 71 Sep 6 65 42 7 6 12.6 24.8 1989 2.66 1994 16.4 38.0 1993 4.22 1994 WATER 17 24 7 621 1 4680 16 12290 2 30 36 7 3 22.4 66.9 1992 6.60 1990 YEARS 1988 .0 .1 .76 Aug .84 Aug .1 Aug Aug .08 AUG .27 .78 .6 .1 23.5 59.5 1989 6.90 1991 - 1995 1993 1994 21 1992 13 1995 7 1995 24 1988 24 1988 e Estimated 168 RIO PUERTO MUEVO BASIN 50048770 RIO PIEDRAS AT EL SENORIAL, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORDS-.-- Water years 1988 to current year. PERIOD OP DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGEi April 1988 to September 1995. INSTRUMENTATION.-- Automatic sediment sampler since 1988. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 24,600 mg/L Sep. 18, 1989; Minimum daily mean, 2 mg/L November 18, 1988. SEDIMENT LOADS: Maximum daily mean, el!4,000tons (e!03,OOOtonnes) Sep. 18, 1989; Minimum daily mean, 0.02 ton (0.02 tonne) June 9, 1994. EXTREMES FOR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,340 mg/L February 28, 1995; Minimum daily mean, S mg/1 several days. SEDIMENT LOADS: Maximum daily mean, 4,910 tons (4,450 tonnes) March 03, 1995; Minimum daily mean, 0.01 ton (0.01 tonne) August 12-13, 1995. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN DISCHARGE DAY (CFS) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL 2.7 2.4 2.5 2.3 2.5 2.4 3.1 45 30 3.7 2.9 2.7 2.7 2.5 2.6 2.3 3.2 9.8 4.8 12 3.7 47 60 21 8.6 6.4 5.3 4.7 5.1 5.0 4.5 313.4 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) OCTOBER 16 16 17 17 17 18 55 674 617 46 31 30 28 27 26 25 49 169 95 441 55 585 1650 814 203 116 114 67 88 95 66 . 2. 253 149 • 19 3. 42 1. 412 338 61 4. 2. 1. . 1. 1. 1296. 12 11 11 10 12 12 2 47 25 22 20 18 18 15 66 5 1 9 0 8 85 3 5 81 95 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) NOVEMBER 35 5. 4. 5. 5. 4. 4. 21 40 59 8. 5. 4. 4. 4. 4. 4. 4. 78 6. 4. 4. 5. 5. 25 19 51 15 51 49 -- 540. 5 8 5 1 7 5 S S 9 6 5 4 5 1 2 8 7 1 5 - 4 506 89 79 111 64 65 78 676 902 847 261 128 89 77 69 63 79 62 594 185 89 75 72 69 462 498 1030 570 622 1410 —— ___ 190 1. 1. 2. 1. 86 242 541 6. 1. 1. . • 1. . 476 4. 1. . 110 55 141 32 114 223 - 2239. 3 0 0 90 83 1 4 9 2 95 84 74 1 68 2 1 96 95 99 -- 14 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) DECEMBER 36 94 26 12 12 12 8. 6. 6. 10 6. 5. 5. 5. 5. 4. 5. 4. 4. 4. 4. 5. 5. 5. 4. 5. 8. 4. 3. 4. 3. 332. 7 9 1 1 6 7 0 4 4 6 3 3 9 7 9 3 8 2 3 9 8 9 9 5 2 770 1790 1290 268 584 416 206 154 120 288 132 92 64 52 50 48 46 44 42 41 40 39 39 38 37 37 213 194 100 54 40 ___ 128 865 99.9 8.6 23 21 7.5 4.6 2.2 26 2.2 1.4 1.0 .70 .73 .57 .69 .50 .49 .54 .50 .63 .55 .60 .43 .52 20 2.6 1.0 .74 .38 1222.57 RIO PUERTO NDEVO BASIN 169 50048770 RIO PIEDRAS AT EL SENORIAL, PR--Continu«d SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 6.6 4.1 8.5 3.0 2.9 4.0 2.8 4.3 7.1 e!4 2.9 33 3.1 3.0 2.0 2.6 1.7 2.2 12 2.0 2.2 1.6 1.5 1.6 1.5 41 «12 019 «4.8 04.6 03.9 204 145 303 34 31 28 27 89 239 312 37 708 89 73 68 63 58 40 200 46 53 39 27 19 13 963 348 567 81 63 49 4. 1. 14 . 1. 13 042 144 . . 37 • . . 166 032 060 01. 0. 0. 7 6 27 24 30 20 3 43 74 60 36 45 26 25 25 31 17 11 08 05 0 75 53 MEAN DISCHARGE (CPS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) MEAN DISCHARGE (CPS) FEBRUARY 03.8 02.5 02.8 03 . 1 02.6 02.5 03 . 1 02 .1 01.9 01.6 09.7 02.0 02. 1 02.0 01.9 2.3 2.7 4.6 87 12 25 3.6 44 3.6 180 36 30 182 ___ ___ ___ 52 31 29 28 26 25 89 25 13 11 335 70 56 45 36 45 82 136 900 494 615 86 254 16 1180 1490 1110 2340 ___ ___ ___ 0. 0. 0. 0. 0. 0. 01. 0. 0. 0. 031 0. 0. 0. 0. 1. 7. 909 29 91 265 . 2520 153 116 2100 - - - 68 20 22 22 19 16 6 14 07 05 37 32 24 19 38 6 1 97 16 -- __ -- 129 19 257 22 11 9. 7. 9. 7. 5. 6. 6. 19 14 5. 4. 3. 4. 4. 4. 8. 3. 3. 3. 3. 3. 3. 3. 3. 3. 2. MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) MARCH 0 9 0 1 8 5 2 9 2 8 5 3 4 0 8 8 5 5 3 9 7 1 0 9 1910 367 2010 981 319 271 234 300 178 110 262 143 904 550 108 52 14 11 10 10 213 69 59 50 42 36 30 25 22 18 15 1260 29 4910 69 9.4 6.9 5.0 9.1 3.5 1.7 10 2.7 65 32 1.8 .60 .15 .13 .12 .12 14 .71 .61 .47 .40 .32 .32 .26 .18 .15 .12 TOTAL 215.5 --- 522.95 656.5 --- 6228.86 592.1 --- 6433.76 « Estimated 170 DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 RIO PUERTO NUBVO BASIN 50048770 RIO PIEDRAS AT EL SENORIAL, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) 2.9 2.8 2.8 2.4 2.2 2.2 3.1 2.5 2.5 6.6 2.1 3.7 1.7 1.6 15 3.8 2.2 1.8 1.9 2.2 2.4 2.3 1.9 1.8 1.7 1.7 1.7 1.8 1.8 1.8 ___ APRIL 13 11 9 8 7 7 6 6 5 93 19 84 21 13 284 63 13 7 7 7 7 6 6 6 6 6 6 6 6 6 ___ MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MAY .10 .08 .07 .05 .04 .04 .05 .04 .04 12 .12 1.5 .09 .06 95 1.3 .08 .04 .04 .04 .04 .04 .03 .03 .03 .03 .03 .03 .03 .03 ___ 1.9 1.9 1.9 2.0 3.6 12 3.8 3.2 3.0 2.6 2.5 2.6 2.7 3.3 32 2.8 1.9 1.7 1.7 2.0 1.5 1.5 1.4 1.5 1.9 2.1 1.6 3.2 2.2 7.3 3.8 6 6 6 6 60 115 44 23 17 12 9 6 5 57 578 40 14 12 11 24 23 19 15 12 10 19 11 34 17 107 72 .03 .03 .03 .03 1.5 15 .49 .19 .13 .08 .06 .04 .04 2.0 440 .42 .07 .05 .05 .19 .09 .08 .06 .05 .05 .18 .05 1.1 .10 16 2.0 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) JUNE 31 14 26 3.6 31 2.4 1.7 4.7 4.0 41 3. 1 1.9 1.6 1.3 25 50 1.9 1.3 1.5 6.6 2.1 1.8 1.8 1.7 1.7 2.1 1.8 1.9 1.7 1.5 495 368 476 58 489 53 44 126 121 459 68 34 23 15 576 471 67 60 53 191 19 16 14 12 10 8 7 6 6 6 ___ 176 37 112 .63 230 .43 .29 11 5.8 201 .62 .18 .10 .05 181 418 .35 .21 .21 13 .11 .08 .07 .05 .04 .05 .03 .03 .03 .02 ___ TOTAL 84.9 111.10 117.1 480.19 271.7 1388.38 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SENORIAL, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- DISCHARGE TRATION DAY (CPS) (MG/L) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR 1.4 1.3 4.8 16 21 27 2.3 2.2 2.1 2.0 4.5 2.6 2.6 18 2.4 1.6 1.5 1.5 1.5 1.6 59 10 15 5.0 2.0 1.9 30 30 5.6 2.0 1.8 280.2 4513.91 JULY 5 5 148 315 514 502 23 20 18 16 140 23 32 184 23 13 12 11 10 13 400 265 303 106 20 37 906 590 157 12 10 —— SEDIMENT DISCHARGE (TONS /DAY) MEAN DISCHARGE (CPS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) AUGUST 9. 54 83 107 5. 61 • . 391 14 31 8. • 1. 133 127 3. . • 1031. 29953. 02 02 1 15 12 10 09 2 17 40 16 06 05 05 04 08 5 11 6 9 07 05 04 08 1. 1. 7. 1. 1. 20 1. 1. 1. 1. 6. 1. 1. 3. 48 25 2. 2. 1. 8. 6. 1. 1. 2. 1. . 14 152 320. 6 4 3 3 5 3 4 5 1 99 91 84 3 2 0 4 3 6 2 2 3 9 3 2 0 97 01 10 9 174 8 8 330 11 8 7 6 6 5 5 167 9 5 82 650 892 24 53 8 230 174 13 7 30 8 6 207 1340 —— .04 .03 20 .03 .03 123 .04 .03 .03 .02 .02 .01 .01 21 .03 .02 3.6 240 92 .16 .80 .02 20 8.6 .07 .03 .49 .02 .02 46 2240 2816.15 MEAN DISCHARGE (CPS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) SEPTEMBER 7.6 3.1 2.5 2.7 9.4 321 15 4.4 2.5 2.2 41 45 4.0 1.8 32 176 11 2.9 1.8 21 34 3.0 2.3 1.7 1.4 1.2 2.1 7.0 28 2.3 789.9 209 33 25 23 298 1850 507 72 20 19 603 543 81 15 237 983 409 33 14 294 414 61 36 30 27 24 39 107 418 22 --- —— 6.5 .28 .16 .16 28 4410 36 .96 .14 .16 414 187 1.2 .07 72 517 18 .27 .07 158 183 1.7 .40 .13 .10 .08 .37 16 130 .14 --- 6181.89 772 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SENORIAL, PR--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DATE NOV 1994 29. .. 29. .. DEC 02. . . FEB 1995 25. .. MAY 15. .. JUN 16. .. JUL 21. .. AUG 18. . . SEP 06. .. DATE NOV 1994 29. .. 29. .. DEC 02. . . FEB 1995 25. .. MAY 15. .. JUN 16. .. JUL 21. .. AUG 18. .. SEP 06. .. TIME 1345 1510 1415 1522 1940 1340 2100 2125 0730 SED. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 88 67 71 41 43 57 59 87 48 DIS- CHARGE, INST. CUBIC FEET PER SECOND 82 175 269 582 493 930 461 282 2000 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 91 78 81 51 52 66 68 90 54 SEDI- MENT, SUS- PENDED (MG/L) 2100 4220 5720 30400 7960 6830 5580 3500 7620 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 99 95 96 58 68 78 82 98 66 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 466 2000 4150 47800 10600 17100 6920 2660 41100 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 99 98 98 69 78 85 88 99 76 SED. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 75 33 43 15 23 39 42 70 30 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 99.6 99 99 86 89 92 92 99.6 84 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 79 41 50 20 28 43 45 73 36 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99.9 99 99.7 98 97 97 97 99.8 94 SED. SUSP. FALL DIAM. PERCENT FINER THAN . 008 MM 84 50 61 28 31 49 50 78 40 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 100 99.9 99.9 99.6 99.9 99 99 99.9 99 173 RIO PUERTO NDEVO BASIN 50048770 RIO PIEDRAS AT EL SENORIAL, PR--Continued HATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT NOV 1994 19.. . DEC 01... 02.. . FEB 1995 23.. . OUN 01.. . 10.. . 15.. . 15.. . 16.. . JUL 23.. . 28.. . AUG 21. .. SEP 06.. . 16.. . TIME 1750 1515 1655 1422 1200 1355 1145 1415 1500 1020 1715 1330 0650 0740 STREAM- FLOW, INSTAN- TANEOUS (CFS) 265 249 97.0 261 168 324 267 210 99.6 190 3060 7.00 2960 270 SEDI- MENT, SUS- PENDED (MG/L) 2070 1760 1480 2120 4000 2060 2840 1640 1290 680 167 113 9320 947 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 1480 1180 388 1490 1810 1800 2050 930 347 349 1380 2.1 74500 700 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 97 86 94 91 87 91 75 86 98 89 81 92 48 75 774 RIO PUERTO NUEVO BASIN 50048800 RIO PIEDRAS NEAR RIO PIEDRAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°22'15 n , long 66°03'40", at bridge on Winston Churchill Avenue in the El Senorial Housing area, 0.5 mi (0.8 km) west of Highway 176, and 2.5 mi (4.0 km) southwest of Rio Piedras plaza. DRAINAGE AREA.--8.17 mi 1 (20.9 km5 ). PERIOD OF RECORD.--Water years 1972 to current year. WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 17. .. DEC 12. .. FEE 1995 21. .. APR 17... JUN 12... AUG 10. . . DATE OCT 1994 17. .. DEC 12. .. FBB 1995 21... APR 17. .. JUN 12. .. AUG 10. . . TIME 0800 1140 0900 0825 0635 0715 HARD- NESS TOTAL (MG/L AS CACO3) 130 -- -- 150 -- 170 SILICA, DATE OCT 1994 17. .. DEC 12. .. FEB 1995 21. . . APR 17. .. JUN 12... AUG 10. .. K = non-ideal DIS- SOLVED (MG/L AS SIO2) 24 -- -- 26 -- 31 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 5.7 6.3 12 5.7 5.1 4.3 CALCIUM DIS- SOLVED (MG/L AS CA) 37 -- -- 40 -- 45 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 231 -- -- 252 -- 282 SPE- CIFIC CON- DUCT- ANCE (US/CM) 401 455 382 404 480 495 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 10 -- __ 11 __ 14 SOLIDS, DIS- SOLVED (TONS PER DAY) 3.54 -- -- 3.87 -_ 3.23 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.2 7.1 7.2 7.1 7.2 7.2 SODIUM, DIS- SOLVED (MG/L AS NA) 24 -- __ 25 __ 30 RESIDUE TOTAL AT 105 DBG. C, SUS- PENDED (MG/L) 32 10 -- 15 9 2 TEMPER- ATURE WATER (DBG C) 25.5 25.5 24.0 24.5 24.0 27.0 SODIUM AD- SORP- TION RATIO 0.9 _- — 0.9 __ 1 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 2.6 2.6 4.4 0.50 0.32 2.8 TUR- BID- ITY (NTU) 13 26 41 7.3 3.2 1.5 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 3.7 -_ __ 3.1 __ 3.8 PHOS- PHORUS TOTAL (MG/L AS P) 0.330 0.350 0.540 0.110 0.070 0.350 OXYGEN, DIS- SOLVED (MG/L) 4.0 3.4 5.4 5.6 3.8 2.3 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CACO3 140 160 130 170 150 180 ARSENIC TOTAL (UG/L AS AS) 3 _- — 2 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 48 41 63 66 45 28 SULFIDB TOTAL (MG/L AS S) <0.5 -- __ <0.5 __ -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) 200 -- -- 100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 43 38 21 14 <10 21 SULFATB DIS- SOLVED (MG/L AS SO4) 17 -- __ 13 __ 14 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 50 -- -- 40 -- — COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 260000 44000 K610000 K90000 22000 K600000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 31 -- __ 32 __ 36 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 — -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 77000 46000 310000 23000 9000 720000 PLUO- RIDB, DIS- SOLVED (MG/L AS F) 0.20 -- __ 0.10 __ 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 1 -- -- <1 -- -- RIO PUERTO NUEVO BASIN 50048800 RIO PIEDRAS NEAR RIO PIEDRAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 175 DATE OCT 1994 17. .. DEC 12. .. FEB 1995 21. .. APR 17. .. JDN 12. .. AUG 10. .. MANGA- METHY- COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) <10 960 3 360 <0.10 <1 <1 30 <0.010 <1 0.46 -- -_ 10 540 1 120 <0.10 <1 <1 20 <0.010 7 0.09 -- -- PESTICIDE ANALYSES CHLOR- DANE, P,P'- P,P'- ENDO- TECH- ODD DOT DI- DI- SULFAN, PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I DATE TIME TOTAL TOTAL TOTAL RECOVER TOTAL RECOVER TOTAL TOTAL TOTAL (OG/L) (OG/L) (OG/L) (OG/L) (OG/L) (UG/L) (UG/L) (OG/L) (OG/L) JON 1995 12... 0635 <0 ENDRIN WATER UNFLTRD DATE REC (OG/L) JUN 1995 12... <0.010 PARA- THION, DATE TOTAL (OG/L) JUN 1995 12... <0.010 .100 <0. ETHION, TOTAL (UG/L) <0.010 PCNS UNPILT RECOVER (UG/L) <0.100 010 <0 HEPTA- CHLOR, TOTAL (UG/L) <0.010 PER- THANE TOTAL (UG/L) <0.100 .100 <0. HEPTA- CHLOR EPOXIDE TOTAL (UG/L) <0.010 TOX- APHENE, TOTAL (UG/L) •cl.OO 010 <0, LINDANE TOTAL (UG/L) <0.010 TOTAL TRI- THION (UG/L) <0.010 .010 <0, MALA- THION, TOTAL (UG/L) <0.010 2,4-D, TOTAL (UG/L) <0.010 .010 0 METH- OXY- CHLOR, TOTAL (UG/L) <0.010 2,4,5-T TOTAL (UG/L) <0.010 .030 <0, METHYL PARA- THION, TOTAL (UG/L) <0.010 2, 4-DP TOTAL (UG/L) <0.010 .010 <0.010 MIREX, TOTAL (UG/L) <0.010 SILVBX, TOTAL (UG/L) <0.010 176 RIO PUERTO NUEVO BASIN 50049100 RIO PIBDRAS AT HATO REY, PR LOCATION.--Lat 18<>24'34", long 66°04'10", Hydrologic Unit 21010005, at bridge on Avenida Pifteiro near Bxpreso Las Americas (Luia A. Perre), and 0.8 mi (1.3 km) southwest of Hato Key. DRAINAGE AREA.--15.4 mi 1 (39.9 km 1 ). 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 ft'/s (0.06 m'/s)), 20 ft (6 m) upstream from gaging station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT NOV MAR APR JUL AUG 1 10 77 2 6.2 10 3 5.0 5.2 4 4.8 16 5 4.9 4.8 6 5.4 6.1 7 54 18 8 59 123 9 146 193 10 55 297 11 9.8 55 12 16 30 13 7.1 23 14 6.0 19 15 5.1 18 16 4.8 18 17 13 41 18 53 16 19 58 593 20 77 52 21 29 24 22 86 14 23 132 13 24 84 11 25 15 129 26 8.5 115 27 28 76 28 8.5 31 29 11 110 30 9.4 106 31 11 TOTAL 1022.5 2244.1 MEAN 33.0 74.8 MAX 146 593 MIN 4.8 4.8 AC-FT 2030 4450 CFSM 2 . 17 4 . 92 IN. 2.50 5.49 38 142 89 65 47 53 36 35 25 23 21 16 16 15 14 14 21 12 12 13 11 11 10 11 e8.9 10 e27 18 9.9 12 13 848.8 27.4 142 8.9 1680 1.80 2.08 STATISTICS OF MONTHLY MEAN DATA MEAN 64.0 77.7 MAX 134 235 (WY) 1991 1993 MIN 16.6 23.9 (WY) 1992 1991 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 50.9 168 1993 18.8 1992 FOR 51 10 15 10 8.8 11 8.5 12 41 60 23 134 14 11 8.5 9.0 7.0 7.9 35 11 8.0 7.1 7.1 7.3 8.0 113 54 97 12 8.9 9.2 819.3 26.4 134 7.0 1630 1.74 2.01 10 8.3 7.2 7.2 7.3 7.1 8.5 8.2 7.1 9.6 75 8.8 8.0 8.0 17 12 11 44 137 58 84 18 e571 e69 604 115 172 341___ ___ --- 2433.3 86.9 604 7.1 4830 5.72 5.96 FOR WATER YEARS 1972 40.6 97.4 1993 12.9 1973 42.0 86.9 1995 10.8 1992 565 152 380 105 34 27 38 36 40 32 34 28 105 59 20 16 14 14 13 13 29 11 11 12 13 12 19 11 11 11 11 1876 60.5 565 11 3720 3.98 4.59 - 1995 40.3 78.5 1972 11.5 1994 1994 CALENDAR YEAR 10588. 29. 593 4. 5. 21000 1. 25. 68 13 6. 6 0 Nov 19 6 Jul 11 9 Sep 29 91 91 3 11 11 10 11 13 13 15 11 14 25 11 18 8.7 8.6 65 48 17 7.7 7.6 7.6 8.3 8.7 7. 1 7.1 7.3 7.5 7.1 7.1 6.9 6.6 --- 406.9 13.6 65 6.6 807 .89 1.00 6.6 6.6 6.6 6.6 e54 el33 47 9.1 5.2 5.6 4.7 8.4 7.0 27 275 74 9.5 8.2 11 60 12 13 12 11 11 109 18 54 50 92 36 1183.1 38.2 275 4.7 2350 2.51 2.90 130 89 118 48 84 61 33 31 28 1050 109 57 41 100 103 149 21 11 15 27 16 14 12 13 13 24 22 9.2 8.6 19--- 2455.8 81.9 1050 8.6 4870 5.39 6.01 7.1 6.5 23 79 142 160 12 12 5.4 5.6 13 6.9 7.8 123 14 8.3 7.7 7.5 6.5 46 253 143 96 26 13 9.8 342 114 60 29 36 1815.1 58.6 342 5.4 3600 3.85 4.44 44 75 100 21 17 99 29 18 18 14 9.7 8.7 9.1 47 10 6.5 51 178 151 20 76 17 73 57 14 9.6 16 6.7 6.5 73 501 1775.8 57.3 501 6.5 3520 3.77 4.35 108 128 27 22 49 1170 136 e62 e48 e43 e780 e840 e80 e35 158 696 104 50 32 254 301 72 68 34 29 59 37 63 115 22 --- 5622 187 1170 22 11150 12.3 13.76 , BY WATER YEAR (WY) 60.2 150 1972 13.6 1995 FOR 1995 22502. 61. 1170 4. 6. 8350 19. 44630 4. 55. 129 18 7. 45.0 97.5 1992 4.12 1972 WATER YEAR 7 7 Sep 6 7 May 11 7 Apr 28 Jun 10 81 Jun 10 06 07 1 43.8 81.9 1995 20.0 1994 46.8 97.4 1993 12.8 1994 WATER 51. 84. 28. 3210 1. 1. 8640 20. 37400 3. 46. 117 21 8. 52.8 84.2 1988 20.2 1993 YEARS 1972 - 6 0 7 Aug 20 2 Jun 28 2 Jul 5 Jun 17 77 Jun 17 40 15 9 73.5 187 1995 26.3 1972 1995 1993 1994 1972 1972 1972 1970 1970 e Estimated 177 RIO PUERTO NOEVO BASIN 50049100 RIO PIEDRAS AT HATO KEY, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'34", long 66°04'10", at bridge on Avenida Pifiiero at Expreso Las Americas, and 0.8 mi (1.3 km) southwest of Hato Key. DRAINAGE AREA.--15.4 mi' (39.9 km 1 ). PERIOD OP RECORD.--Water years 1971 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 17. .. DEC 28. . . FEB 1995 21. . . APR 17... JUN 20. . . AUO 10. . . DATE OCT 1994 17. .. DEC 28. . . FEB 1995 21. .. APR 17. .. JUN 20. .. AUO 10. . . TIME 1035 0940 1045 1015 1125 1135 HARD- NESS TOTAL (HO/L AS CACO3) 140 -- -- 140 -- 170 SILICA, DATE OCT 1994 17... DEC 28. .. FEB 1995 21. . . APR 17. . . JUN 20. . . AUO 10. . . K = non- ideal DIS- SOLVED (HO/L AS SIO2) 26 -- -- 22 -- 28 count DIS- CHAROE, INST. CUBIC FEET PER SECOND 15 13 17 17 12 12 CALCIUM DIS- SOLVED (MG/L AS CA) 41 -- -- 40 -- 50 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 257 -- -- 226 -- 287 SPE- CIFIC CON- DUCT- ANCE (US/CM) 446 335 448 384 552 500 MAGNE- SIUM, DIS- SOLVED (MO/L AS HO) 9.0 -- -- 9.3 -- 12 SOLIDS, DIS- SOLVED (TONS PER DAY) 10.6 -- -- 10.1 -- 9.00 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.3 7.2 7.2 7.1 7.5 7.4 SODIUM, DIS- SOLVED (HO/L AS NA) 29 -- -- 23 -- 33 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 25 9 16 24 6 3 TEMPER- ATURE WATER (DEG C) 28.0 25.0 23.5 27.0 29.0 31.0 SODIUM AD- SORP- TION RATIO 1 -- -- 0.9 -- 1 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 5.2 1.1 2.3 1.4 1.3 1.7 TUR- BID- ITY (NTU) 2.9 2.8 4.8 7.8 2.2 2.3 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 5.2 __ __ 3.4 _- 4.2 PHOS- PHORUS TOTAL (MG/L AS P) 0.620 0.210 0.350 0.220 0.220 0.360 OXYOEN, DIS- SOLVED (MG/L) 1.0 4.4 4.3 4.8 2.7 3.8 ALKA- LINITY WAT WH TOT FET FIELD HO/L AS CACO3 160 180 150 140 180 180 ARSENIC TOTAL (UG/L AS AS) 3 -- -- 2 -- -- OXYOEN, DIS- SOLVED (PER- CENT SATUR- ATION) 13 52 50 59 35 51 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 -- - - BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) 100 -- -- 100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MO/L) 150 21 29 30 16 19 SULFATE DIS- SOLVED (HG/L AS SO4) 16 -- -- 16 -- 15 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 70 -- -- 40 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS. / 100 ML) 560000 320000 440000 230000 37000 26000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 35 -- -- 28 -- 37 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- — STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 240000 61000 76000 K180000 88000 24000 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.20 -- -- 0.10 -- 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 1 -- -- 1 -- -- 178 RIO PUERTO NDEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS FE) AS PB) AS MN) AS HG) AS SB) AS AG) AS ZN) AS CN) (UG/L) OCT 1994 17. .. DEC 28. .. FEB 1995 21. .. APR 17. .. JUN 20. . . AUG 10. .. 10 880 910 310 170 <0.10 <0.10 40 <0.010 20 <0.010 (MG/L) 1.0 0.28 179 RIO PUERTO NUEVO BASIN 50049820 LACUNA SAN JOSE NO. 2 AT SAN JUAN, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°25'46 n , long 66°02'10", 0.2 mi (0.3 km) eaat of Cano de Martin Pena, and 650 ft (200 m) aouth of lala Guachinango. DRAINAGE AREA.--Indeterminate. PERIOD OP RECORD.--Water yeara 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE NOV 1994 16. .. FEB 1995 24. .. MAR 16. . . MAY 10. .. JUN 29. .. JUL 05. .. SEP 25. .. DATE NOV 1994 16. .. FEB 1995 24. .. MAR 16. .. MAY 10. .. JUN 29. .. JUL 05. .. SEP 25. .. TIME 0950 0920 0845 1020 1120 1020 0945 COLI- FORM, FECAL, 0.45 DM-MF (COLS./ 100 ML) K70000 K86000 K670 K10 K670 370 K71000 SPE- CIFIC CON- DUCT- ANCE (US/CM) 28600 28600 32300 30400 23600 32500 21700 STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K16000 3700 67 K45 K10 40 3500 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.6 6.5 7.2 7.3 8.3 7.0 7.0 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 150 130 110 89 92 100 110 TEMPER- ATURE WATER (DEG C) 29.5 27.0 26.5 29.0 31.5 28.0 29.0 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 9 20 18 15 15 3 29 TRANS- PAR- ENCY (SECCHI DISK) (IN) 10.8 36.0 41.8 43.2 19.2 18.0 38.4 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 2.8 3.0 2.6 1.4 2.1 1.1 3.0 OXYGEN, DIS- SOLVED (MG/L) 1.0 0.5 4.7 1.6 10.4 5.7 3.0 PHOS- PHORUS TOTAL (MG/L AS P) 0.680 0.450 0.570 0.290 0.720 0.230 0.810 OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 13 7 57 23 152 71 41 CARBON, ORGANIC TOTAL (MG/L AS C) 13 8.8 5.2 8.2 8.9 6.4 7.9 K = non-ideal count 180 RIO PUERTO NtJEVO BASIN 50049920 BAHIA DE SAN JUAN NO. 5 AT SAN JUAN, PR WATER-QUALITY RECORDS LOCATION--Lat .t. J.B-ZO-J/ , xong e& w i south from U.S. Naval .determinate CORD--Water • us' ii , u .« mi <u, Reservation. . t> Km; we uonstitu' years 1974 to present. WATER- QUALITY DATE NOV 1994 07. .. DEC 29. .. FEB 1995 23. .. HAY 09. .. JUN 26. .. SEP 22. . . DATE NOV 1994 07... DEC 29. .. FEB 1995 23. .. MAY 09. .. JUN 26. .. SEP 22. .. TIME 1120 0650 1030 1005 1000 0945 COLI- FORH, FECAL, 0.45 UM-HF (COLS./ 100 ML) K270 K1700000 K600000 270000 26000 K78000 DATA, WATER YEAR SPE- CIFIC CON- DUCT- ANCE (US/CM) 50000 36900 >50000 6600 36000 15500 STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K100 K170000 71000 36000 K160 40000 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.6 7.3 7.2 7.2 7.7 6.3 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 110 150 150 150 150 120 OCTOBER TEMPER- ATURE WATER (DEG C) 30.0 27.5 27.0 30.0 30.0 28.0 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 15 11 27 12 7 24 1994 TO SEPTEMBER TRANS- PAR- ENCY (SECCHI DISK) (IN) 14.0 16.0 19.2 10.0 12.4 7.20 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.40 4.1 4.6 3.3 2.6 0.90 OXYGEN, DIS- SOLVED (MG/L) 4.5 0.6 3.6 0.2 4.1 1.3 PHOS- PHORUS TOTAL (MG/L AS P) 0.030 0.660 0.650 0.470 0.530 0.110 1995 OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 56 9 47 3 61 17 CARBON, ORGANIC TOTAL (MG/L AS C) 2.0 15 12 11 4.6 6.3 K = non-ideal count cion, and 0.5 mi EXPLANATION SURFACE-WATER STATION A 0509 AND NUMBER w „„, QUALITY-OF-WATER STATION T Ubb4 AND NUMBER Y7 QUALITY-OF-WATER PARTIAL v 0575 RECORD STATION AND NUMBER *0564 DAILY SEDIMENT STATION AND NUMBER 222 WELL AND WELL NUMBER n,on LAKE-ELEVATION STATION Ubyu AND NUMBER Figure 20.--Rio Grande de Loiza basin. 182 RIO GRANDE DE LOIZA BASIN 50050300 QUEBRADA BLASINA NEAR CAROLINA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°23'27", long 65°58'28 n , 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 mi 2 (7.67 km2 ). PERIOD OP RECORD.—Water years 1973 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 18. .. DEC 09. .. FEB 1995 07. .. HAY 01. .. JUN 26. .. AUG 11... DATE OCT 1994 18. .. DEC 09. .. FEB 1995 07... HAY 01. .. JUN 26. .. AUG 11... DATE OCT 1994 18. .. DEC 09. .. FEB 1995 07... HAY 01. .. JUN 26... AUG 11. .. TIME 1025 0945 1055 0945 0735 1005 HARD- NESS TOTAL (HG/L AS CAC03) 130 — — 180 -- 160 SILICA, DIS- SOLVED (HG/L AS SIO2) 15 -- -_ 29 — 25 DIS- CHARGE, INST. CUBIC FEET PER SECOND 12 6.7 5.4 4.8 10 6.6 CALCIUM DIS- SOLVED (HG/L AS CA) 40 -- -- 57 -_ 51 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (HG/L) 195 -- __ 319 -- 286 SPE- CIFIC CON- DUCT- ANCE (US/CH) 353 500 500 490 490 505 MAGNE- SIUM, DIS- SOLVED (MG/L AS HG) 6.2 — — 10 — 8.7 SOLIDS, DIS- SOLVED (TONS PER DAY) 6.28 — — 4.17 — 5.13 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.2 7.4 7.3 7.0 7.3 7.3 SODIUM, DIS- SOLVED (HG/L AS NA) 17 -- __ 35 __ 28 RESIDUE TOTAL AT 105 DEC. C, SUS- PENDED (MG/L) 458 15 4 5 26 10 TEMPER- ATURE WATER (DBG C) 26.0 25.0 25.0 27.0 25.0 28.0 SODIUM AD- SORP- TION RATIO 0.7 — __ 1 — 1 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (HG/L AS N) 3.4 1.1 0.90 4.2 0.88 1.1 TUR- BID- ITY (NTU) 280 5.1 1.6 2.1 15 6.0 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 4.2 -- __ 4.1 __ 3.6 PHOS- PHORUS TOTAL (HG/L AS P) 0.710 0.230 0.220 0.610 0.210 0.180 OXYGEN, DIS- SOLVED (HG/L) 4.0 3.0 2.3 1.8 3.0 1.2 ALKA- LINITY WAT WH TOT FET FIELD HG/L AS CACO3 120 190 170 210 160 200 ARSENIC TOTAL (UG/L AS AS) 3 -- -- 2 — — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 48 36 27 22 36 15 SULFIDE TOTAL (HG/L AS S) <0.5 — __ 0.8 __ -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) 200 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 110 27 18 27 23 16 SULFATE DIS- SOLVED (MG/L AS SO4) 17 — -_ 12 — 13 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 50 -- — 70 — — COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 470000 22000 32000 41000 8000 K9500 CHLO- RIDE, DIS- SOLVED (HG/L AS CL) 24 -- -- 46 _- 37 . CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 550000 870 2500 32000 900 4400 FLUO- RIDE, DIS- SOLVED (HG/L AS F) 0.10 — — 0.10 — 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 5 — — <1 — — K = non-ideal count 183 RIO GRANDE OB LOIZA BASIN 50050300 QUEBRADA BLASINA NEAR CAROLINA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUB ACTIVE SUB- STANCE AS CU) AS FB) AS PB) AS MN) AS HG) AS SB) AS AG) AS ZN) AS CN) (UG/L) (MG/L) OCT 1994 18. .. DEC 09. .. FEE 1995 07... MAY 01... JUN 26. .. AUG 11. . . 10 7000 7 3700 <0.10 50 <0.010 <1 0.13 410 840 <0.10 <0.010 8 0.08 184 RIO GRANDE DE LOIZA BASIN 50050900 RIO GRANDE DE LOIZA AT QUEBRADA ARENAS, PR LOCATION.--Lat 18°07'10", long 65°59'22", Hydrologio Unit 21010005, at intersection of Highways 181 and 9990, 0.2 mi (0.3 km) upstream from confluence with Rio Emajagua and about 7.1 mi (11.4 km) southwest of San Lorenzo. DRAINAGE AREA.--6.00 mi* (15.54 km1 ). WATER-DISCHARGE RECORDS PERIOD OP RECORD.--October 1977 to current year. GAGE.—Water-stage recorder. Elevation of gage is 640 ft (195 m), from topographic map. REMARKS.--Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC PEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT NOV FEE MAR APR JUN JUL AUG 1 9.4 23 2 9.6 21 3 10 21 4 9.9 60 5 9.7 29 6 9.2 109 7 13 77 8 9.7 95 9 9.7 55 10 10 117 11 9.2 65 12 8.0 41 13 7.5 34 14 8.5 30 15 8.2 28 16 6.9 26 17 7.4 25 18 21 24 19 10 23 20 8.5 23 21 12 25 22 102 34 23 292 25 24 261 21 25 207 26 26 75 34 27 45 43 28 35 28 29 30 35 30 27 41 31 25 —— TOTAL 1306.4 1238 MEAN 42.1 41.3 MAX 292 117 MIN 6.9 21 AC-PT 2590 2460 CPSM 7.02 6.88 IN. 8.10 7.69 STATISTICS OP MONTHLY MEAN MEAN 40.9 46.3 MAX 123 122 (WY) 1986 1988 MIN 13.1 8.34 (WY) 1990 1990 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW- INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW PLOW ANNUAL RUNOFF (AC-PT) ANNUAL RUNOFF (CPSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 171 198 64 59 37 29 26 24 23 22 57 28 28 31 70 29 25 25 23 22 21 25 24 27 27 22 19 22 18 17 16 1229 39.6 198 16 2440 6.61 7.62 DATA 24.7 55.2 1988 6.65 1990 POR 16 15 16 16 17 15 14 14 14 13 12 16 13 14 15 12 12 12 11 11 10 10 10 9.9 10 58 16 14 13 12 11 451.9 14.6 58 9.9 896 2.43 2.80 10 11 9.9 9.1 8.9 8.4 18 17 11 10 12 10 9.3 8.7 10 16 18 20 30 35 183 35 19 15 225 52 48 39___ ___ --- 898.3 32.1 225 8.4 1780 5.35 5.57 POR WATER YEARS 1978 18.2 56.1 1992 8.16 1990 18.2 38.0 1982 6.36 1979 24 20 18 27 42 42 28 46 39 27 22 22 26 20 17 16 15 15 14 14 14 13 13 12 13 12 12 12 12 12 11 630 20.3 46 11 1250 3.39 3.91 - 1995 12.8 33.1 1989 5.07 1979 1994 CALENDAR YEAR 9089.4 24.9 593 4.9 5.4 18030 4.15 56.35 41 11 6.3 Sep 20 May 3 Apr 27 11 11 11 11 12 11 13 11 10 9.6 14 27 13 11 11 15 10 9.5 9.2 9.1 8.6 8.3 8.1 8.0 7.9 7.4 7.3 7.3 7.3 7.3 --- 316.9 10.6 27 7.3 629 1.76 1.96 7.0 6.6 6.3 6.0 6.5 6.7 12 14 13 8.4 7.2 6.6 6.1 6.0 6.3 6.0 5.8 5.6 6.2 12 8.6 8.2 6.4 8.0 6.4 6.1 6.1 8.1 16 39 47 314.2 10.1 47 5.6 623 1.69 1.95 33 218 130 102 35 33 27 17 11 9.2 48 11 8.8 9.1 53 28 15 11 8.7 7.8 10 8.3 7.0 6.2 6.0 5.5 5.3 5.2 4.9 4.7 —— 878.7 29.3 218 4.7 1740 4.88 5.45 4.8 4.6 4.7 12 13 11 13 11 8.6 6.7 7.0 15 12 12 36 33 18 19 13 10 13 20 24 14 12 15 148 34 25 95 45 709.4 22.9 148 4.6 1410 3.81 4.40 27 39 93 32 24 21 25 70 49 42 40 38 34 31 29 29 34 115 510 156 74 52 39 36 74 32 25 43 26 20 18 1877 60.5 510 18 3720 10.1 11.64 17 16 15 14 21 291 126 88 41 31 48 42 31 25 106 365 311 84 58 111 76 54 85 53 43 38 38 35 82 37 ___ 2382 79.4 365 14 4720 13.2 14.77 , BY WATER YEAR (WY) 12.8 27.1 1985 4.64 1979 POR 1995 12231. 33. 510 4. 4. 11770 8. 4. 24260 5. 75. 70 17 7. 32.0 77.5 1985 9.56 1988 WATER YEAR 8 5 Aug 19 6 Jul 2 9 Jun 27 Aug 19 05 Aug 19 5 Jun 29 59 84 3 37.4 122 1979 11.3 1985 36.1 92.3 1993 12.5 1986 WATER 29. 49. 14. 1250 3. 3. 18200 17. 2. 21150 4. 66. 50 15 6. 31.5 90.0 1979 9.30 1991 YEARS 1978 2 6 5 Oct 1 May 6 May Jan 52 Jan 8 Hay 87 11 9 39.2 94.3 1979 11.8 1981 - 1995 1979 1990 6 1985 7 1979 1 1979 5 1992 5 1992 5 1979 185 RIO GRANDE DE LOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR LOCATION.--Lat 18°09'40", long 65°58'58", Hydrologic Unit 21010005, 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 mi j (8.42 km3 ). 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT DEC JAN JUN JUL AUG 1 1.1 2.1 2 1.2 1.8 3 1.4 1.8 4 1.5 2.1 5 1.6 2.2 6 1.6 17 7 1.7 8.2 8 1.7 14 9 1.6 9.0 10 1.7 7.5 11 1.6 6.5 12 1.4 4.4 13 1.6 3.3 14 1.6 2.7 15 1.7 2.7 16 1.6 3.0 17 1.8 2.6 18 e5.3 1.9 19 2.0 1.7 20 1.6 1.7 21 1.4 2.5 22 5.1 2.1 23 25 1.8 24 39 1.4 25 12 3.7 26 6.8 9.8 27 4.6 9.9 28 3.4 3.7 29 2.9 6.6 30 2.5 8.0 31 2.1 —— TOTAL 140.1 145.7 MEAN 4.52 4.86 MAX 39 17 MIN 1.1 1.4 AC-FT 278 289 CFSM 1.39 1.49 IN. 1.60 1.67 STATISTICS OF MONTHLY MEAN MEAN 10.4 16.1 MAX 47.8 36.9 (WY) 1986 1985 MIN 2.75 2.49 (WY) 1993 1990 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN -DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 11 11 7.0 6.1 4.7 4.5 4.2 3.7 3.2 3.0 2.9 2.7 2.6 3.3 4.8 3.2 2.8 2.5 2.4 2.3 2.2 2.3 2.4 2.1 2.0 2.0 2.0 2.3 2.0 1.5 1.5 110.2 3.55 11 1.5 219 1.09 1.26 1.7 1.7 2.5 2.2 1.7 1.5 1.4 1.3 1.3 1.3 1.4 3.4 2.1 1.7 1.4 1.2 1.2 1.1 1.0 .99 .95 .91 .90 .87 .87 5.7 2.5 3.6 2.4 1.7 1.5 53.99 1.74 5.7 .87 107 .54 .62 DATA FOR WATER 6.90 30.1 1988 1.49 1990 FOR 4.39 9.94 1992 1.74 1995 1.3 1.1 1.2 1.2 1.2 1.1 1.2 1.3 1.0 3.5 1.6 1.2 .96 .79 .81 .91 1.1 1.0 1.3 1.0 9.3 3.8 2.0 1.4 6.9 7.1 5.3 4.3 ___ ___ --- 64.87 2.32 9.3 .79 129 .71 .74 YEARS 1984 3.93 8.21 1989 1.32 1985 2.8 2.2 1.6 3.1 5.0 2.5 2.1 2.3 3.3 2.4 1.8 1.5 2.2 4.5 3.5 2.9 2.5 2.2 1.9 1.7 1.6 1.5 1.4 1.2 1.2 .98 1.2 .93 .88 .88 .83 64.60 2.08 5.0 .83 128 .64 .74 - 1995 4.00 20.7 1989 1.64 1993 1994 CALENDAR YEAR 1216. 3. 201 . 2410 1. 13. 5. 1. 98 33 Sep 20 33 May 20 37 Apr 26 03 93 3 6 56 .80 .79 .79 .78 .95 .85 1.1 .87 .70 .67 .90 2.2 1.1 .88 .87 e.86 .74 .81 .92 .93 .89 .82 .82 .83 .95 .96 .96 .94 .90 .88 —— 27.46 .92 2.2 .67 54 .28 .31 .93 .93 .84 .83 .85 .90 1.2 4.2 2.2 .95 .81 .75 .72 .72 .76 .75 .68 .66 .67 .92 .83 .79 .67 e.65 e.53 .73 .96 1.1 2.4 6.9 4.7 41.53 1.34 6.9 .53 82 .41 .48 2.4 15 32 10 4.0 2.1 1.6 1.0 .75 .61 .54 .55 .44 .41 4.6 4.1 2.9 1.5 .94 1.0 1.2 .74 .62 .57 .54 .53 7.1 3.0 1.4 1.0 —— 103.14 3.44 32 .41 205 1.06 1.18 .85 .76 .68 .66 2.2 1.4 1.4 1.0 .84 .78 .70 4.6 10 7.0 8.2 8.9 11 8.9 4.2 2.3 2.0 2.6 1.8 5.1 3.6 1.7 71 12 6.1 10 5.1 197.37 6.37 71 .66 391 1.96 2.26 3.9 2.7 9.0 3.4 2.6 2.2 2.0 2.8 2.4 2.3 2.2 2.1 2.2 2.4 2.5 2.6 3.4 30 63 24 13 16 11 8.9 25 11 7.5 5.9 4.9 4.7 4.9 280.5 9.05 63 2.0 556 2.78 3.21 4.2 3.5 2.7 2.7 10 84 26 30 13 7.7 6.8 5.6 4.0 3.0 36 69 42 21 14 14 14 8.4 11 6.6 5.5 5.0 4.9 4.2 8.9 4.7 472.4 15.7 84 2.7 937 4.85 5.41 , BY WATER YEAR (WY) 2.16 4.88 1989 .75 1994 FOR 1995 1701 4 84 2920 10 3380 1 19 9 2 7.46 31.5 1985 .62 1994 5.63 21.3 1987 2.12 1994 WATER YEAR .86 .66 .41 .61 .34 .39 .43 .48 .9 .1 .80 Sep 6 Jun 14 Jun 8 Sep 6 Sep 6 Jun 13 5.79 15.0 1993 2.02 1986 WATER 6 12 2 457 7400 14 4910 2 28 12 2 6.30 20.2 1988 1.95 1994 YEARS 1984 .78 .3 .50 Dec . 33 May . 37 Apr May .58 May .30 May .09 .36 .4 .9 8.23 15.7 1995 1.36 1990 - 1995 1988 1990 7 1987 20 1994 26 1994 17 1985 17 1985 21 1994 e Estimated 186 RIO GRANDE DE LOIZA BASIN 50051150 QDEBRADA BLANCA AT EL JAGUAL, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1985 to 1986 and water year 1989 to current year. PERIOD OP DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1984 to September 1986 and from October 1989 to September 1995. INSTRUMENTATION.-- Automatic sediment sampler since 1989. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis and during high flow events. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 7,300 mg/L Oct. 06, 1985; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 4,940 tons (23,400 tonnes) May 17, 1985; Minimum daily mean, <0.01 ton (<0.01 tonne) several days. EXTREMES FOR CURRENT YEAR 1995.-- SEDIHENT CONCENTRATION: Maximum daily mean, 635 mg/L July 27, 1995; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 597 tons (538 tonnes) September 06, 1995; Minimum daily mean, <0.01 ton (,0.01 tonnes) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 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 1.1 3 .01 2.1 4 .02 11 44 3.4 2 1.2 6 .02 1.8 10 .05 11 100 3.1 3 1.4 10 .04 1.8 14 .07 7.0 38 .74 4 1.5 5 .02 2.1 16 .09 6.1 16 .26 5 1.6 2 .01 2.2 12 .07 4.7 5 .06 6 1.6 2 .01 17 76 19 4.5 4 .05 7 1.7 3 .01 8.2 8 .17 4.2 5 .06 8 1.7 2 .01 14 71 6.7 3.7 10 .10 9 1.6 1 .01 9.0 14 .36 3.2 24 .21 10 1.7 1 <.01 7.5 7 .15 3.0 12 .10 11 1.6 1 <.01 6.5 6 .11 2.9 5 .04 12 1.4 1 <.01 4.4 7 .08 2.7 2 .02 13 1.6 3 .01 3.3 7 .06 2.6 2 .01 14 1.6 6 .02 2.7 7 .05 3.3 6 .09 15 1.7 8 .04 2.7 5 .03 4.8 15 .21 16 1.6 11 .05 3.0 2 .02 3.2 8 .07 17 1.8 12 .05 2.6 2 .02 2.8 6 .05 18 e5.3 32 e.62 1.9 3 .02 2.5 5 .03 19 2.0 19 .10 1.7 3 .01 2.4 4 .03 20 1.6 8 .03 1.7 2 .01 2.3 5 .03 21 1.4 3 .01 2.5 2 .02 2.2 7 .04 22 5.1 51 2.5 2.1 6 .03 2.3 8 .05 23 25 99 9.6 1.8 13 .06 2.4 9 .06 24 39 219 27 1.4 8 .03 2.1 9 .05 25 12 38 1.4 3.7 10 .13 2.0 8 .05 26 6.8 10 .18 9.8 39 6.3 2.0 8 .04 27 4.6 4 .05 9.9 43 1.8 2.0 7 .04 28 3.4 2 .02 3.7 15 .15 2.3 5 .03 29 2.9 2 .01 6.6 18 .42 2.0 2 .01 30 2.5 1 .01 8.0 18 .40 1.5 1 <.01 31 2.1 1 .01 —— —— —— 1.5 3 .01 TOTAL 140.1 —— 41.85 145.7 —— 36.43 110.2 —— 9.04 e Estimated RIO GRANDE DE LOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 187 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1.7 1.7 2.5 2.2 1.7 1.5 1.4 1.3 1.3 1.3 1.4 3.4 2.1 1.7 1.4 1.2 1.2 1.1 1.0 .99 .95 .91 .90 .87 .87 5.7 2.5 3.6 2.4 1.7 1.5 6 10 5 2 3 5 4 3 2 1 1 8 2 3 6 10 5 3 14 15 14 13 12 9 6 11 3 2 1 1 6 .03 .05 .03 .01 .02 .02 .01 .01 .01 <.01 <.01 .11 .01 .01 .02 .03 .02 .01 .04 .04 .03 .03 .03 .02 .01 .23 .02 .02 .01 .01 .02 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) FEBRUARY 1.3 1.1 1.2 1.2 1.2 1.1 1.2 1.3 1.0 3.5 1.6 1.2 .96 .79 .81 .91 1.1 1.0 1.3 1.0 9.3 3.8 2.0 1.4 6.9 7.1 5.3 4.3 ___ ___ 21 12 6 3 2 1 1 1 1 27 16 8 4 9 25 35 41 19 8 3 41 12 3 1 25 22 14 12 ___ ___ .07 .04 .02 .01 .01 <.01 <.01 <.01 <.01 .28 .07 .03 .01 .02 .05 .09 .12 .05 .03 .01 2.4 .13 .02 <.01 1.5 .53 .22 .17 ___ MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/ DAY) MARCH 2.8 2.2 1.6 3.1 5.0 2.5 2.1 2.3 3.3 2.4 1.8 1.5 2.2 4.5 3.5 2.9 2.5 2.2 1.9 1.7 1.6 1.5 1.4 1.2 1.2 .98 1.2 .93 .88 .88 .83 9 7 5 7 17 15 17 19 14 11 13 16 15 11 3 2 2 2 2 1 1 1 1 1 1 1 1 2 3 3 • 3 .07 .04 .02 .09 .24 .10 .10 .12 .12 .07 .06 .07 .09 .18 .03 .02 .01 .01 .01 .01 .01 .01 .01 .01 .01 .01 .01 .01 .01 .01 .01 TOTAL 53.99 0.91 64.87 5.88 64.60 1.50 188 RIO GRANDE DE LOIZA BASIN 50051150 QOEBRADA BLANCA AT EL JAGUAL, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 .80 .79 .79 .78 .95 .85 1.1 .87 .70 .67 .90 2.2 1.1 .88 .87 e.86 .74 .81 .92 .93 .89 .82 .82 .83 .95 .96 .96 .94 .90 .88 APRIL 2 1 1 1 2 1 1 1 2 2 3 4 4 4 4 5 5 7 9 9 8 5 3 2 2 2 5 15 17 19 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MAY .01 .01 .01 .01 .01 .01 .01 .01 .01 .01 .01 .02 .01 .01 .01 e.Ol .01 .02 .02 .02 .02 .01 .01 <.01 •c.Ol <.01 .01 .04 .04 .05 .93 .93 .84 .83 .85 .90 1.2 4.2 2.2 .95 .81 .75 .72 .72 .76 .75 .68 .66 .67 .92 .83 .79 .67 e.65 e.53 .73 .96 1.1 2.4 6.9 4.7 18 12 7 4 2 2 2 16 12 1 4 11 6 2 1 1 1 2 4 7 13 16 5 1 1 2 3 5 12 18 12 .05 .03 .02 .01 <.01 <.01 .01 .58 .11 <.01 .01 .02 .01 <.01 <.01 <.01 <.01 <.01 .01 .02 .03 .03 .01 •c.Ol <.01 <.01 .01 .02 .12 .49 .16 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) •TONE 2.4 15 32 10 4.0 2.1 1.6 1.0 .75 .61 .54 .55 .44 .41 4.6 4.1 2.9 1.5 .94 1.0 1.2 .74 .62 .57 .54 .53 7.1 3.0 1.4 1.0 8 47 170 24 10 5 4 6 9 10 9 9 11 13 10 18 20 11 7 4 3 5 7 7 6 5 20 10 7 5 .05 3.0 21 .67 .11 .03 .02 .02 .02 .02 .01 .01 .01 .01 .15 .22 .16 .05 .02 .01 .01 .01 .01 .01 .01 .01 2.4 .09 .03 .01 27.46 0.32 41.53 1.75 103.14 28.18 e Estimated 189 RIO GRANDE DE-LOIZA BASIN 50051150 QUEBRADA BLAHCA AT EL JAGUAL, PR--Continu«d SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR .85 .76 .68 .66 2.2 1.4 1.4 1.0 .84 .78 .70 4.6 10 7.0 8.2 8.9 11 8.9 4.2 2.3 2.0 2.6 1.8 5.1 3.6 1.7 71 12 6.1 10 5.1 197.37 1701.86 JULY 3 2 1 1 6 3 7 12 17 17 4 13 58 13 23 28 28 27 18 8 3 3 2 10 7 3 635 32 15 46 20 —— MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) AUGUST .01 <.01 •c.Ol •c.Ol .04 .01 .03 .03 .04 .03 .01 .24 7.4 .38 .99 .75 1.3 .69 .22 .05 .02 .02 .01 .26 .08 .01 228 1.1 .27 2.8 .31 245.10 1421.31 3.9 2.7 9.0 3.4 2.6 2.2 2.0 2.8 2.4 2.3 2.2 2.1 2.2 2.4 2.5 2.6 3.4 30 63 24 13 16 11 8.9 25 11 7.5 5.9 4.9 4.7 4.9 280.5 12 28 61 28 9 7 5 8 11 11 11 12 14 13 5 2 2 183 567 112 41 63 30 23 126 31 17 10 6 3 3 —— .13 .20 1.6 .28 .06 .04 .03 .06 .07 .07 .07 .07 .08 .08 .04 .02 .02 29 120 7.7 1.5 4.1 1.2 .56 14 .90 .34 .17 .08 .04 .04 182.55 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) SEPTEMBER 4.2 3.5 2.7 2.7 10 84 26 30 13 7.7 6.8 5.6 4.0 3.0 36 69 42 21 14 14 14 8.4 11 6.6 5.5 5.0 4.9 4.2 8.9 4.7 ___ 472.4 3 3 4 4 39 540 137 169 19 6 2 2 3 3 250 417 237 27 9 29 47 11 40 10 4 6 9 9 13 12 ___ —— .03 .03 .03 .03 2.6 597 24 17 .69 .12 .04 .04 .03 .03 63 120 35 1.7 .33 1.3 2.1 .26 1.4 .19 .06 .08 .12 .10 .32 .17 867.80 190 RIO GRANDE DE LOIZA BASIN 50051150 QDEBRADA BLANCA AT EL JAGOAL--Continued HATER QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DATE OCT 1994 24.. . DEC 02.. . JAN 1995 09.. . SEP 25.. . TIME 1010 1040 1035 1020 STREAM- FLOW, INSTAN- TANEOUS (CPS) 63 10 1.3 29 SEDI- MENT, SUS- PENDED (MG/L) 170 89 2 192 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 29 2. 0. 15 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 98 4 90 01 50 98 191 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR LOCATION.—Lat 18°10'24 H , long 65°58'38", Hydrologic Unit 21010005, on left downstream side of bridge on Highway 181, 0.2 ml (0.3 km) upstream from Rio Granda de Lo£za, and 1.5 mi (2.4 km) southwest of San Loranzo. DRAINAGE AREA.--3.74 mi 9 (9.69 km 9 )* WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1984 to currant year. OAGE.--Water-stage recorder and crast-stage gage. Elevation of gage is 330 ft (100 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT DEC JAN MAR MAY JUN JUL AUO 1 1.1 1.3 2 1.0 1.2 3 .98 1.2 4 .92 4.6 5 .92 1.6 6 1.0 20 7 1.2 6.5 8 1.3 11 9 1.2 8.6 10 1.2 7.8 11 1.1 6.6 12 1.1 3.7 13 1.1 2.7 14 1.0 2.1 15 1.0 1.7 16 .97 1.6 17 1.1 1.5 18 10 1.4 19 1.8 1.3 20 1.4 1.4 21 1.3 1.5 22 17 1.4 23 38 1.3 24 71 1.2 25 17 2.1 26 5.9 9.2 27 3.3 10 28 2.3 3.6 29 1.8 12 30 1.5 11 31 1.4 —— TOTAL 191.89 141.1 MEAN 6.19 4.70 MAX 71 20 MIN .92 1.2 AC-FT 381 280 CFSM 1.66 1.26 IN. 1.91 1.40 STATISTICS OF MONTHLY MEAN MEAN 9.29 13.4 MAX 36.2 33.4 (WY) 1986 1988 MIN 2.31 2.72 (WY) 1987 1990 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK PLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 18 17 8.7 5.6 3.8 3.5 3.2 2.7 2.5 2.2 2.0 1.9 3.0 2.8 3.3 2.0 1.8 1.7 1.7 1.7 1.7 1.8 2.0 1.9 1.8 1.8 1.6 1.8 1.6 1.6 1.5 108.2 3.49 18 1.5 215 .93 1.08 DATA 5.32 22.8 1988 1.17 1990 FOR 1.7 1.5 1.6 1.7 1.4 1.5 1.3 1.3 1.4 1.3 1.2 1.5 1.3 1.1 1.0 1.0 .92 .92 .92 .92 .92 .91 .85 .91 .93 3.4 1.5 1.8 1.3 1.1 1.0 40.10 1.29 3.4 .85 80 .35 .40 .94 .92 1.0 1.0 1.1 1.1 1.2 1.3 1.4 3.1 1.5 1.4 1.3 1.2 1.1 1.2 1.2 1.2 1.1 1.1 2.5 2.4 1.3 1.1 4.6 6.8 4.8 2.5 ___ ___ —— 51.36 1.83 6.8 .92 102 .49 .51 FOR WATER YEARS 1984 4.66 23.4 1992 1.16 1990 3.16 10.3 1984 1.23 1990 2.1 1.7 1.2 2.0 2.1 1.4 1.3 1.3 1.8 1.-7 1.3 1.2 1.3 1.2 1.5 1.9 1.7 1.7 1.5 1.3 1.4 1.2 1.0 1.0 1.2 1.1 el.O el.O el.O el.O e.92 43.02 1.39 2.1 .92 85 .37 .43 - 1995 3.20 17.4 1989 1.15 1992 1994 CALENDAR YEAR 1468.94 4.02 314 .45 .54 2910 1.08 14.61 5.8 1.2 .63 Sep 20 Aug 17 May 26 e.85 e.85 a. 85 e.85 a. 78 e.68 a. 65 e.62 a. 67 a. 60 e.60 el. 5 a. 88 e.70 a. 70 a. 74 e.71 e.62 e.54 e.53 e.50 e.50 a. 51 a. 47 e.50 e.50 e.50 e.48 e.41 a. 43 --- 19.72 .66 1.5 .41 39 .18 .20 e.45 e.45 al.4 e9.0 a. 44 a22 a. 41 a. 43 e.46 e.62 e3.0 el. 2 e.56 a. 50 a. 56 e.56 e.57 e.45 e.44 e.45 a. 60 a. 60 e.65 e.61 e.44 e.38 e.43 e.46 e.47 a. 55 e.66 el. 8 e4.5 e3.0 26.70 .86 4.5 .38 53 .23 .27 e8.4 e2.4 el. 4 el. 2 .76 .56 .45 .41 .42 .32 .30 e3.3 e3.2 el. 8 .99 .70 .76 .90 .58 .48 .43 .41 e.40 e3.5 e2.3 el.O e.78 --- 70.55 2.35 22 .30 140 .63 .70 e.68 e.58 a. 56 a. 48 el. 6 e.98 e.98 e.78 e.68 e.60 a. 56 a4.0 a8.4 a5.8 e6.8 e7.0 e8.6 a7.0 e3.0 el. 6 el. 5 el. 9 el. 3 a3.8 e2.8 el. 6 e56 e6.2 e5.9 e20 5.0 166.68 5.38 56 .48 331 1.44 1.66 2.7 1.2 13 2.9 2.1 2.0 2.2 2.1 1.9 1.7 1.4 1.3 1.2 1.2 1.2 1.1 1.2 35 64 12 6.3 21 7.8 5.4 19 5.8 3.5 2.7 2.4 2.1 1.8 229.2 7.39 64 1.1 455 1.98 2.28 1.9 1.7 1.4 1.3 5.4 175 24 23 10 5.8 5.6 4.6 3.6 3.1 48 117 39 19 12 9.3 12 7.0 9.4 5.7 4.8 4.4 4.6 4.4 6.7 4.7 574.4 19.1 175 1.3 1140 5.12 5.71 , BY WATER YEAR (WY) 2.39 6.60 1985 .66 1995 FOR 1995 1662 4 175 2000 10 3300 1 16 8 1 7.03 35.8 1985 .86 1995 WATER YEAR .92 .56 Sep 6 .30 Jun 14 .43 Apr 29 Sep 6 . 60 Sep 6 .71 Aug 3 .22 .54 .6 .4 .54 6.08 15.0 1984 1.63 1994 5.50 20.5 1993 1.45 1994 WATER 6 10 3 472 9320 17 4630 1 23 10 1 5.32 14.4 1988 1.51 1994 YEARS 1984 .39 .4 .19 .29 .41 .10 .26 .71 .21 .9 .90 Nov Sep May May May May 11.7 29.0 1989 1.88 1990 - 1995 1988 1990 27 1987 12 1990 19 1990 17 1985 17 1985 30 1990 e Estimated 192 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR--Continue WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1984 to 1986 and water years 1989 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1994 to September 19*95. INSTRUMENTATION: Automatic sediment sampler since 1984. REMARKS:-- Sediment samples were collected by a local observer on a weekly basis and during high flow events. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 7,300 mg/L Oct. 06, 1985; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 11,100 tons (10,100 tonnes) Jan. 05, 1992; Minimum daily mean, <0.01 ton (<0.01 tonne) several days. EXTREMES FOR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATION: Maximum daily mean, 839 mg/L September 06, 1995; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 1,630 tons (1,480 tonnes) September 06, 1995 ; Minimum daily mean, e<0.01 ton (e<0.01 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE )AY (CFS) (MG/L) (TONS/DAY) MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) OCTOBER 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1.1 1.0 .98 .92 .92 1.0 1.2 1.3 1.2 1.2 1.1 1.1 1.1 1.0 1.0 .97 1.1 10 1.8 1.4 1.3 17 38 71 17 5.9 3.3 2.3 1.8 1.5 1.4 3 5 6 9 11 10 9 11 13 16 19 18 8 3 3 4 4 45 17 11 5 175 167 295 75 19 15 14 13 12 11 .01 .01 .02 .02 .03 .03 .03 .04 .05 .05 .06 .05 .02 .01 .01 .01 .01 2.8 .08 .04 .02 49 30 71 4.1 .33 .13 .08 .06 .05 .04 1. 1. 1. 4. 1. 20 6. 11 8. 7. 6. 3. 2. 2. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 2. 9. 10 3. 12 11 -- MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) NOVEMBER 3 2 2 6 6 5 6 8 6 7 7 1 7 6 5 4 3 4 5 4 3 2 1 2 6 - 8 6 5 18 7 140 23 47 31 34 27 18 18 15 5 4 5 7 9 12 15 10 7 5 9 131 88 14 126 119 .03 .02 .02 .70 .03 26 .44 3.3 .78 .87 .51 .18 .13 .09 .02 .02 .02 .03 .03 .05 .06 .04 .02 .02 .06 31 4.2 .13 8.0 3.3 _-- 18 17 8. 5. 3. 3. 3. 2. 2. 2. 2. 1. 3. 2. 3. 2. 1. 1. 1. 1. 1. 1. 2. 1. 1. 1. 1. 1. 1. 1. 1. DECEMBER 7 6 8 5 2 7 5 2 0 9 0 8 3 0 8 7 7 7 7 8 0 9 8 8 6 8 6 6 5 85 150 40 17 9 11 14 15 8 6 4 3 14 12 16 7 5 4 3 2 1 3 5 4 3 2 2 2 3 4 5 18 7.5 .98 .26 .09 .10 .12 .11 .05 .03 .02 .02 .14 .13 .15 .04 .02 .02 .01 .01 .01 .01 .03 .02 .01 .01 .01 .01 .01 .02 .02 TOTAL 191.89 158.19 141.1 80.10 108.2 27.96 RIO GRANDE DE LOIZA BASIN I 93 50051160 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR-Continue SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL 1.7 1.5 1.6 1.7 1.4 1.5 1.3 1.3 1.4 1.3 1.2 1.5 1.3 1.1 1.0 1.0 .92 .92 .92 .92 .92 .91 .85 .91 .93 3.4 1.5 1.8 1.3 1.1 1.0 40.10 6 6 4 4 7 12 6 2 1 3 8 10 10 12 14 14 6 2 2 3 3 4 5 10 17 10 6 8 12 17 19 .03 .03 .02 .02 .03 .05 .02 .01 .00 .01 .03 .04 .03 .04 .04 .04 .01 .01 .01 .01 .01 .01 .01 .02 .04 .09 .02 .04 .04 .05 .05 0.86 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MEAN DISCHARGE (CFS) FEBRUARY .94 .92 1.0 1.0 1.1 1.1 1.2 1.3 1.4 3.1 1.5 1.4 1.3 1.2 1.1 1.2 1.2 1.2 1.1 1.1 2.5 2.4 1.3 1.1 4.6 6.8 4.8 2.5 --- 51.36 20 23 24 22 20 17 9 6 18 38 18 7 3 3 7 8 8 7 7 7 16 30 28 24 31 36 61 23 ___ ___ --- .05 .06 .06 .06 .06 .05 .03 .02 .06 .32 .08 .03 .01 .01 .02 .02 .02 .02 .02 .02 .11 .19 .09 .07 .90 .94 .87 .14 ___ ___ --- 4.33 2.1 1.7 1.2 2.0 2.1 1.4 1.3 1.3 1.8 1.7 1.3 1.2 1.3 1.2 1.5 1.9 1.7 1.7 1.5 1.3 1.4 1.2 1.0 1.0 1.2 1.1 el.O el.O el.O el.O e.92 43.02 MARCH 9 .05 7 .03 6 .02 9 .06 7 .04 5 .02 5 .02 7 .02 6 .03 4 .02 6 .02 8 .02 10 .04 15 .05 18 .07 9 .04 4 .02 5 .02 5 .02 6 .02 7 .02 8 .02 9 .02 10 .03 11 .03 12 .04 12 e.03 5 e.Ol 2 e.Ol 2 e.Ol 3 e.Ol 0.88 e Estimated 194 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR-Continu« SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 JAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MEAN DISCHARGE (CPS) «.85 «.85 «.85 «.85 «.78 e.68 e.65 «.62 «.67 e.60 e.60 • 1.5 «.88 e.70 e.70 «.74 e.71 «.62 «.54 «.53 «.50 «.50 «.51 e.47 «.50 «.50 e.50 «.48 «.41 «.43 ___ MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) APRIL 2 1 1 1 1 1 2 3 3 4 8 12 5 2 2 1 1 3 7 11 13 7 4 3 8 17 9 4 2 2 «<.01 «<.01 e<.01 e<. 01 «<.01 e<.01 e<.01 «<.01 «.01 «.01 e.Ol «.03 «.02 «<.01 «<.01 «<.01 «<.01 «<.01 «.01 «.02 «.02 «.01 «<.01 «<.01 «.01 «.02 «.01 «<.01 e<.01 «<.01 TOTAL 19.72 0.18 MEAN DISCHARGE (CPS) «.45 «.45 «.44 «.41 «.43 «.46 e.62 «3.0 el. 2 e.56 «.50 e.56 e.56 e.57 «.45 «..44 «.45 e. 60 e.60 «.65 e.44 e.38 «.43 «.46 e.47 «.55 e.66 «1.8 «4.5 «3.0 26.70 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) MAY 1 4 9 6 3 5 8 11 7 4 3 3 6 11 16 8 4 10 20 14 8 5 4 5 9 16 16 15 15 21 28 «< e< e e «< e e e e e «< e< e e e e «< e e e e e «< e< e e e e e e e .01 .01 .01 .01 .01 .01 .01 .04 .04 .01 .01 .01 .01 .02 .02 .01 .01 .01 .03 .02 .01 .01 .01 .01 .01 .02 .02 .02 .05 .17 .28 MEAN DISCHARGE (CPS) •1.4 •9.0 •22 e8.4 e2.4 el. 4 el. 2 .76 .56 .45 .41 .42 .32 .30 •3.3 e3.2 el. 8 .99 .70 .76 .90 .58 .48 .43 .41 e.40 •3.5 e2.3 el.O e.78 MEAN CONCEN- TRATION (MG/L) •TONE 19 16 60 58 19 16 15 9 6 9 16 25 23 23 41 61 31 13 8 17 31 15 7 S 10 14 19 23 11 5 SEDIMENT DISCHARGE (TONS/DAY) e.ll e.23 •2.5 •2.4 e.26 «.08 «.05 «.02 e.Ol e.Ol *.02 *.03 *.02 *.02 *.16 «.53 *.21 • .05 • .02 e.03 *.07 • .03 • .01 e.Ol e.Ol • .02 e.08 • .18 • .05 • .01 0.84 70.55 7.23 e Eatimated RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR-Continue SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) e e e e el e e e e e e e4 e8 e5 e6 e7 e8 e7 e3 el el el el e3 e2 el e56 e6 e5 e20 5 TOTAL 166 YEAR e 1662 .68 .58 .56 .48 .6 .98 .98 .78 .68 .60 .56 .0 .4 .8 .8 .0 .6 .0 .0 .6 .5 .9 .3 .8 .8 .6 .2 .9 .0 .68 .92 JULY 5 5 6 12 19 10 6 7 9 12 14 15 23 17 19 27 32 19 12 18 25 19 14 10 7 5 62 69 24 231 32 —— MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) AUGUST e.Ol e.Ol e.Ol e.02 e.05 e.04 e.02 e.02 e.02 e.02 e.02 e.07 e.39 e.33 e.33 e.50 e.67 e.39 e.15 e.10 e.ll e.09 e.06 e.06 e.06 e.03 e5.1 e6.1 e.39 e59 .56 74.73 2478.10 2.7 1.2 13 2.9 2.1 2.0 2.2 2.1 1.9 1.7 1.4 1.3 1.2 1.2 1.2 1.1 1.2 35 64 12 6.3 21 7.8 5.4 19 5.8 3.5 2.7 2.4 2.1 1.8 229.2 13 5 82 25 12 10 13 8 6 10 18 17 15 15 20 24 17 97 308 47 11 94 27 22 126 23 13 8 6 5 3 —— .11 .02 5.2 .21 .07 .05 .08 .05 .03 .05 .07 .06 .05 .05 .06 .07 .05 23 88 1.6 .20 13 .63 .32 11 .38 .12 .06 .04 .03 .02 144.68 1. 1. 1. 1. 5. 175 24 23 10 5. 5. 4. 3. 3. 48 117 39 19 12 9. 12 7. 9. 5. 4. 4. 4. 4. 6. 4. -- 574. SEPTEMBER 9 7 4 3 4 8 6 6 6 1 3 0 4 7 8 4 6 4 7 7 - 4 2 4 6 10 25 839 45 109 25 9 9 12 3 3 348 400 195 47 20 19 47 19 34 14 5 7 11 10 19 19 ___ —— .01 .02 .02 .03 .82 1630 4.6 7.3 .74 .14 .19 .15 .03 .02 132 166 28 2.5 .64 .53 1.8 .38 .96 .22 .06 .09 .14 .12 .37 .24 1978.12 Estimated 196 RIO GRANDE DE LOIZA BASIN 50051180 QDEBRADA SALVATIERRA NR. SAN LORENZO, PR--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1993 TO SEPTEMBER 1994 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DATE OCT 1994 22. .. NOV 06. .. 26. .. SEP 1995 06. . . 16. .. TIME 1917 1225 2322 0650 0030 DIS- CHARGE, INST. CUBIC FEET PER SECOND 172 95 79 975 110 SEDI- MENT, SUS- PENDED (MG/L) 4650 2961 4671 8683 3433 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 2160 759 996 22900 1020 SED. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 60 73 61 17 25 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 68 77 68 25 30 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 72 80 76 33 35 DATE OCT 1994 22. . . NOV 16.. . 26... SEP 1995 06.. . 16.. . SED. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 80 88 83 41 45 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 88 89 88 51 52 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 97 98 98 64 65 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 98 99 99.6 79 74 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 99 99.7 99.9 88 81 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99.6 99.7 99.9 93 88 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 100 99.8 100 97 96 197 RIO GRANDE DE LOIZA BASIN 50051180 QUBBRADA SALVATIERRA NEAR SAN LORENZO--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DATE OCT 1994 22. .. 24.. . NOV 06.. . 27.. . 30.. . JAN 1995 23.. . JUN 02.. . JDL 30.. . SEP 06.. . 06.. . 16.. . 16.. . TIME 2037 0950 1315 0042 1010 1010 1040 1520 0610 0850 0330 1020 STREAM- PLOW, INSTAN- TANEOUS (CPS) 74 124 143 28 12 0.85 9 145 115 439 547 67 SEDI- MENT, SUS- PENDED (MG/L) 922 348 646 905 142 4 368 2700 4530 1090 438 196 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 184 116 249 68 4.6 0.01 9 1060 1410 1290 647 35 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 98 98 97 98 94 100 81 93 74 90 88 98 198 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR LOCATION.--Lat 18°09'13", long 65°57'20", Hydrologic Unit 21010005, at downstream side of bridge on Highway 912, at Barrio Cerro Gordo, 2.8 mi (4.5 km) south of San Lorenzo. DRAINAGE AREA.--10.2 mi 2 (26.4 km2 ). WATER-DISCHARGE RECORDS PERIOD OP RECORD.--October 1977 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 490 ft (150 m), from topographic map. Prior to Oct. 1, 1983, at site 2,000 ft (610 m) downstream at different datum. REMARKS.--Records poor. Sand removal at a commercial level is practiced at times during the year. This takes place about one hundred feet downstream from the low water control. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT DEC JAN FEB JUN AUG 1 17 21 2 17 20 3 16 19 4 16 19 5 15 23 6 15 39 7 18 54 8 17 43 9 17 43 10 16 49 11 16 50 12 16 32 13 16 29 14 17 29 15 17 29 16 18 28 17 17 29 18 20 29 19 19 29 20 20 30 21 19 33 22 25 32 23 86 33 24 120 30 25 125 35 26 54 42 27 26 45 28 23 37 29 22 44 30 21 48 31 21 —— TOTAL 882 1023 MEAN 28.5 34.1 MAX 125 54 HIN 15 19 AC-FT 1750 2030 CFSH 2.79 3.34 IN. 3.22 3.73 STATISTICS OF MONTHLY MEAN MEAN 61.0 71.2 MAX 176 196 (WY) 1986 1988 MIN 14.4 19.2 (WY) 1992 1982 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 77 183 48 46 35 34 32 30 29 29 34 30 29 29 34 27 26 26 25 25 24 24 25 23 22 22 21 21 20 20 20 1070 34.5 183 20 2120 3.38 3.90 DATA 45.3 163 1988 12.5 1992 FOR 20 19 20 19 19 18 18 18 19 18 18 18 19 19 21 19 18 18 19 19 19 18 17 16 16 37 23 20 19 18 17 596 19.2 37 16 1180 1.88 2.17 FOR WATER 29.4 50.0 1993 14.6 1990 16 17 15 15 14 13 14 17 14 16 13 13 11 11 10 12 14 11 13 18 79 47 26 21 74 55 39 39 ___ ___ --- 657 23.5 79 10 1300 2.30 2.40 YEARS 1977 27.1 67.5 1984 11.0 1992 27 21 21 33 49 31 26 44 34 28 24 23 25 23 22 21 20 19 18 17 16 16 16 16 15 15 15 15 14 14 14 692 22.3 49 14 1370 2.19 2.52 - 1995 21.8 45.4 1989 11.3 1992 1994 CALENDAR YEAR 9193. 25. 921 7. 8. 18240 2. 33. 34 18 9. 6 2 Sep 20 9 Jun 24 5 Jun 19 47 53 9 14 13 14 13 15 14 16 e!4 e!2 ell e!3 21 13 e!2 ell e!4 e!2 ell ell ell ell ell ell elO elO elO elO elO e9.8 e9.6 --- 367.4 12.2 21 9.6 729 1.20 1.34 e9.6 e9.6 e9.4 e9.3 e9.0 e9.3 e9.6 ell 17 ell e9.8 e9.6 e9.3 e9.3 el3 elO e9.8 e9.8 e!2 15 16 13 11 11 11 11 12 12 16 24 e31 380.4 12.3 31 9.0 755 1.20 1.39 23 e70 78 59 e33 29 25 23 20 20 20 18 18 19 45 42 36 22 19 18 18 17 16 15 15 e!5 e!5 e!4 e!4 e!4 --- 790 26.3 78 14 1570 2.58 2.88 e!4 e!3 e!3 e!5 e20 e!7 e!7 e!7 e!4 e!2 e!2 e!6 e!3 e!7 e!7 e29 e23 e21 e!6 e!4 e!4 e!6 e20 e!6 e!4 e!3 e!27 51 27 40 45 713 23.0 127 12 1410 2.25 2.60 35 32 75 40 27 24 23 29 23 19 17 15 14 14 13 13 16 e45 el!3 51 31 38 30 26 63 31 22 18 18 15 15 945 30.5 113 13 1870 2.99 3.45 14 13 12 12 22 264 73 54 34 29 51 53 44 33 47 155 247 76 57 70 72 51 50 45 41 39 40 40 40 37 1815 60.5 264 12 3600 5.93 6.62 , BY WATER YEAR (WY) 19.9 46.0 1985 10.7 1980 FOR 1995 9930 27 264 9 9 1400 10 19700 2 36 48 19 11 46.1 155 1985 9.68 1990 WATER YEAR .8 .2 Sep 6 . 0 May 5 .4 Apr 30 Sep 6 . 8 6 Sep 6 .67 .22 46.0 140 1979 10.9 1994 42.8 118 1979 15.4 1994 WATER 42 89 18 2900 7 8 13200 9 30880 4 56 66 24 12 44.6 202 1979 14.5 1991 YEARS 1977 - .6 .7 .6 Aug 31 . 1 Feb 4 .5 Jun 19 Aug 31 .44 Aug 31 .18 .78 55.6 216 1979 16.9 1980 1995 1979 1990 1979 1981 1994 1979 1979 e Estimated RIO GRANDE DE LOIZA BASIN 50051800 RIO GRANDE DE LOIZA AT HWY 183 NEAR SAN LORENZO, PR LOCATION.--Lat 18°11'09", long 65°57'42", Hydrologic Unit 21010005, at upstream side of bridge on Highway 183 by-pass, 0.4 mi (0.6 km) south from Plaza de San Lorenzo, 1.4 mi (2.2 km), southwest from Escuela Rafael Col6n Garcia and 2.0 mi (3.2 km) northwest from Escuela Segunda Unidad de Carlos Zayas. DRAINAGE AREA.--25.0 mi' (64.8 km1 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.—February 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 262 ft (80 m), from topographic map. REMARKS.--Records fair except those for estimated discharges, which are poor. Water purification plant located about 0.2 mi (0.3 km) upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 199 DAY NOV DEC JAN FEB MAR APR MAY AUG SEP 1 42 57 2 41 54 3 36 51 4 35 85 5 33 73 6 33 172 7 40 198 8 38 164 9 38 155 10 38 164 11 33 166 12 30 99 13 29 83 14 27 71 15 30 65 16 26 62 17 24 61 18 81 60 19 38 54 20 40 56 21 38 61 22 97 64 23 334 63 24 332 53 25 288 64 26 193 93 27 110 143 28 86 68 29 72 95 30 66 120 31 60 - — TOTAL 2408 2774 MEAN 77.7 92.5 MAX 334 198 MIN 24 51 AC-FT 4780 5500 CFSM 3.11 3.70 IN. 3.58 4.13 STATISTICS OF MONTHLY MEAN MEAN 118 134 MAX 266 222 (WY) 1991 1992 MIN 77.6 92.5 (WY) 1993 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CPSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 150 319 194 163 116 102 91 80 73 67 96 79 74 71 130 83 74 73 69 69 65 67 76 71 70 68 63 64 59 56 54 2886 93.1 319 54 5720 3.72 4.29 DATA 88.5 110 1993 69.7 1994 FOR 55 54 55 59 53 53 48 48 48 46 46 56 57 47 52 43 41 41 40 40 39 38 37 36 37 140 65 55 50 38 36 1553 50.1 140 36 3080 2.00 2.31 FOR WATER 97.4 192 1992 50.1 1995 32 36 33 33 29 27 28 55 40 54 39 40 e32 e30 29 40 63 44 69 80 233 141 72 56 226 244 188 168 --- 2161 77.2 244 27 4290 3.09 3.22 YEARS 1990 63.8 102 1994 21.0 1992 131 100 86 103 204 136 116 154 135 110 85 78 87 86 70 64 58 52 51 49 47 45 45 41 37 37 35 36 33 32 30 2373 76.5 204 30 4710 3.06 3.53 - 1995 45.7 76.5 1995 17.4 1992 1994 CALENDAR YEAR 24451 67. 1870 14 16 48500 2. 36. 108 46 21 0 Sep 20 Aug 17 May 30 68 38 30 28 27 26 27 26 29 28 22 20 20 58 29 23 21 36 22 19 19 18 18 15 16 16 15 14 15 14 13 14 678 22.6 58 13 1340 .90 1.01 13 13 13 12 12 19 19 28 67 27 20 15 15 14 18 16 14 14 15 26 32 23 19 16 18 14 18 21 31 92 106 780 25.2 106 12 1550 1.01 1.16 55 240 299 203 94 70 58 52 40 35 68 40 34 36 168 147 124 69 53 47 64 48 38 32 31 29 34 39 27 24 2298 76.6 299 24 4560 3.06 3.42 22 22 18 19 48 37 34 37 31 25 23 51 67 73 97 131 84 70 57 37 36 63 59 57 46 32 386 177 108 164 196 2307 74.4 386 18 4580 2.98 3.43 114 96 234 119 76 62 51 74 65 48 46 36 34 35 33 28 38 192 600 260 164 168 126 120 217 117 87 79 83 60 55 3517 113 600 28 6980 4.54 5.23 51 48 47 42 66 903 290 303 177 133 153 172 129 107 212 629 493 298 230 249 255 193 223 185 153 140 130 125 190 141 --- 6467 216 903 42 12830 8.62 9.62 , BY WATER YEAR (WY) 28.3 41.5 1993 16.8 1992 FOR 1995 30202 82. 903 12 13 5490 14. 59910 3. 44. 180 55 20 69.6 186 1992 25.2 1995 WATER YEAR 7 Sep 6 May 4 Apr 29 Sep 6 88 Sep 6 31 94 116 290 1992 42.3 1994 97.6 208 1993 42.3 1994 WATER 94 134 67 3380 6 7 40700 31 68340 3 51 164 56 22 90.6 132 1992 39.3 1994 YEARS 1990 .3 .8 Jan .3 Apr .4 Apr Jan .37 Jan .77 .26 145 255 1992 59.7 1990 - 1995 1992 1994 5 1992 29 1992 25 1992 5 1992 5 1992 e Estimated 200 RIO GRANDE DE LOIZA BASIN 50051600 RIO GRANDE DE LOIZA AT HWY 163 NEAR SAN LORENZO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1990 to current year. PERIOD OP DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE! February 1990 to September 1995. INSTRUMENTATION.-- Automatic sediment sampler since 1990. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis and during high flow events EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,340 mg/L September 20, 1994; Minimum daily mean, 5 mg/L Several days. SEDIMENT LOADS: Maximum daily mean, 46,600 tons (42,400 tonnes) Jan. 05, 1992; Minimum daily mean, 0.20 ton (0.16 tonne) May 05, 1992. EXTREMES FOR HATER YEARS 1990-92.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,560 mg/L August 16, 1995; Minimum daily mean, 4 mg/L December 30, 1994. SEDIMENT LOADS: Maximum daily mean, 5,470 tons (4950 tonnes) September 06, 1995; Minimum daily mean, 0.67 ton (0.59 tonne)December 30, 1994. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN CONCEN- SEDIMENT THATION DISCHARGE (MG/L) (TONS/DAY) DECEMBER MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) OCTOBER 1 2 3 4 5 6 7 6 9 10 11 12 13 14 15 16 17 16 19 20 21 22 23 24 25 26 27 26 29 30 31 TOTAL 42 41 36 35 33 33 40 36 36 36 33 30 29 27 30 26 24 61 36 40 38 97 334 332 268 193 110 66 72 66 60 2408 20 21 24 31 42 60 76 52 33 27 64 124 100 73 51 35 27 91 56 33 51 173 642 463 444 103 41 25 16 13 12 2 2 2 2 3 5 6 5 3 2 5 10 7 5 4 2 1 23 6 3 5 136 790 514 519 62 12 5 3 2 1 2162 .2 .4 .3 .9 .7 .3 .1 .4 .4 .6 .6 .7 .2 .2 .5 .6 .3 .7 .1 .6 .5 .3 .9 .1 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MEAN DISCHARGE (CFS) NOVEMBER 57 54 51 65 73 172 196 164 155 164 166 99 63 71 65 62 61 60 54 56 61 64 63 53 64 93 143 66 95 120 --- 2774 26 52 65 101 56 266 358 233 340 354 277 63 36 15 13 15 30 51 39 26 21 25 26 21 15 30 161 23 62 136 --- 4. 7. 9. 30 11 213 207 135 146 196 137 23 6. 2. 2. 2. 5. 6. 5. 4. 3. 4. 4. 3. 2. 15 102 4. 20 44 -- 1361. 0 5 0 6 9 3 5 0 3 6 2 5 4 6 0 6 3 - 7 150 319 194 163 116 102 91 60 73 67 96 79 74 71 130 63 74 73 69 69 65 67 76 71 70 66 63 64 59 56 54 2666 150 319 194 163 116 102 91 60 73 67 96 79 74 71 130 63 74 73 69 69 65 67 76 71 70 66 63 64 59 56 54 292 946 340 232 149 76 40 23 26 32 420 535 104 24 176 29 19 15 11 7 5 6 14 17 20 23 20 16 6 4 5 215 1000 179 102 47 21 9.6 5.0 5.0 5.6 134 119 21 4.6 74 6.5 3.7 2.9 2.1 1.2 .83 1.5 2.6 3.3 3.9 4.2 3.5 2.6 1.3 .67 .76 1964.16 RIO GRANDE DB LOIZA BASIN 50051800 RIO GRANDE DB LOIZA AT HWY 183 NEAR SAN LORENZO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 201 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 55 54 55 59 53 53 48 48 48 46 46 56 57 47 52 43 41 41 40 40 39 38 37 36 37 140 65 55 50 38 36 7 9 14 17 13 9 8 7 7 13 22 22 22 20 18 17 15 14 13 12 11 10 10 13 20 313 324 252 205 147 58 1.1 1.4 2.1 2.7 1.8 1.3 1.0 .88 .90 1.6 2.7 3.4 3.3 2.6 2.6 2.0 1.7 1.5 1.4 1.3 1.1 1.0 .95 1.2 2.0 158 58 37 28 16 5.7 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) FEBRUARY MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MARCH 32 36 33 33 29 27 28 55 40 54 39 40 «32 «30 29 40 63 44 69 80 233 141 72 56 226 244 188 168 25 28 34 35 36 38 44 42 35 62 41 22 14 21 27 27 26 28 29 32 440 212 101 63 863 653 214 143 2. 2. 3. 3. 2. 2. 3. 6. 3. 9. 4. 2. el. el. 2. 2. 4. 3. 5. 7. 438 93 20 9. 1770 537 106 64 2 7 0 1 8 8 4 4 7 4 2 4 2 8 2 9 5 3 5 1 6 131 100 86 103 204 136 116 154 135 110 85 78 87 86 70 64 58 52 51 49 47 45 45 41 37 37 35 36 33 32 30 98 65 44 106 300 146 176 66 42 32 37 44 48 35 26 30 33 30 26 23 21 18 16 14 13 11 11 15 20 25 27 35 18 10 47 182 67 58 27 15 9.5 8.4 9.3 11 8.2 5.0 5.1 5.1 4.2 3.6 3.1 2.6 2.2 2.0 1.6 1.3 1.1 1.0 1.4 1.8 2.1 2.3 1553 346.23 2161 3112.2 2373 550.9 « Estimated 202 RIO GRANDE DE LOIZA BASIN 50051800 RIO GRANDE DE LOIZA AT HWY 183 NEAR SAN LORENZO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 30 28 27 26 27 26 29 28 22 20 20 58 29 23 21 36 22 19 19 18 18 15 16 16 15 14 15 14 13 14 ___ APRIL 23 18 16 23 33 39 42 32 23 17 17 38 28 29 27 30 25 27 43 107 198 167 129 103 94 83 56 39 33 28 1.8 1.4 1.2 1.6 2.4 2.8 3.3 2.4 1.4 .95 .91 6.3 2.2 1.8 1.5 3.0 1.5 1.4 2.2 5.2 9.4 6.9 5.4 4.4 3.8 3.1 2.2 1.5 1.1 1.1 ___ MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MAY MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) JUNE 13 13 13 12 12 19 19 28 67 27 20 15 15 14 18 16 14 14 15 26 32 23 19 16 18 14 18 21 31 92 106 25 23 23 30 41 57 80 125 164 54 39 33 38 44 46 31 22 25 30 32 30 23 25 29 44 63 65 66 70 140 99 .87 .79 .82 1.0 1.3 2.9 4.0 9.8 33 4.0 2.2 1.4 1.5 1.7 2.3 1.3 .84 .94 1.2 2.2 2.7 1.4 1.2 1.3 2.2 2.4 3.1 3.7 6.0 47 30 55 240 299 203 94 70 58 52 40 35 68 40 34 36 168 147 124 69 53 47 64 48 38 32 31 29 34 39 27 24 47 582 607 207 57 42 32 19 11 10 49 28 21 17 309 360 125 39 14 16 58 41 31 25 19 14 25 57 31 22 7.0 462 516 113 15 7.9 5.0 2.7 1.2 .98 12 3.1 1.9 1.6 174 142 44 7.4 2.0 2.1 10 5.3 3.3 2.2 1.5 1.1 3.5 6.3 2.3 1.4 TOTAL 678 84.16 780 175.06 2298 1557.78 RIO GRANDE DE LOIZA BASIN 50051800 RIO GRANDE DE LOIZA AT HWY 183 NEAR SAN LORENZO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) JULY 203 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR 22 22 18 19 48 37 34 37 31 25 23 51 67 73 97 131 84 70 57 37 36 63 59 57 46 32 386 177 108 164 196 2307 30202 22 22 18 19 48 37 34 37 31 25 23 51 67 73 97 131 84 70 57 37 36 63 59 57 46 32 386 177 108 164 196 29 40 52 52 60 117 187 121 71 52 105 160 137 49 116 148 54 33 23 32 89 62 36 23 20 18 725 84 25 214 257 1. 2. 2. 2. 7. 12 17 12 5. 3. 6. 22 63 14 69 54 12 6. 3. 3. 8. 11 5. 3. 2. 1. 1250 47 7. 174 161 7 4 6 8 9 9 5 5 1 6 1 5 6 5 4 5 7 MEAN DISCHARGE (CPS) MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) AUGUST 114 96 234 119 76 62 51 74 65 48 46 36 34 35 33 28 38 192 600 260 164 168 126 120 217 117 87 79 83 60 55 94 54 285 65 40 30 23 19 15 10 26 24 16 13 26 50 61 1560 1280 468 257 96 39 30 373 126 41 27 70 13 44 29 15 199 22 8. 5. 3. 3. 2. 1. 5. 2. 1. 1. 2. 3. 6. 1020 2670 332 114 45 13 9. 271 41 9. 8. 17 2. 6. 3 0 1 8 7 3 1 3 5 3 3 8 5 7 8 2 2 4 SEPTEMBER 51 48 47 42 66 903 290 303 177 133 153 172 129 107 212 629 493 298 230 249 255 193 223 185 153 140 130 125 190 141 ___ 137 158 165 174 193 868 96 651 256 71 105 177 22 16 294 632 434 50 41 42 42 38 22 12 7 8 8 9 125 151 ___ 19 21 21 20 36 5470 130 580 127 26 69 88 7 4 257 1420 724 41 26 28 29 20 13 6 3 2 2 2 77 58 - .9 .7 .2 .1 .8 .8 .9 -- 1993.3 27529.31 3517 4871.3 6467 9330.4 204 RIO GRANDE DE LOIZA BASIN 50051800 RIO GRANDE DE LOIZA AT HWY 183 NEAR SAN LORENZO, PR—Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DATE AUG 1995 18. .. 18. .. SEP 06. .. 06. .. DATE AUG 1995 18. .. 18. .. SEP 06. .. 06. .. TIME 0950 1010 0745 0800 SED. SUSP. FALL DIAM. PERCENT FINER THAN 016 MM 51 54 49 52 DIS- CHARGE, INST. CUBIC FEET PER SECOND 296 282 5490 4800 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 76 78 62— SEDI- MENT, SUS- PENDED (MG/L) 7390 6770 5330 3540 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 98 98 73 81 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 5900 5160 79000 45900 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 99.6 99.6 89 92 SED. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 25 26 25 29 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 99.8 99.8 96 98 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 29 31 31 34 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99.9 99.9 99 99.6 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 38 39 38 40 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 99.9 99.9 99.6 99.8 RIO GRANDE DE LOIZA BASIN 50051800 RIO GRANDE DE LOIZA AT HWY 183 NEAR SAN LORENZO, PR--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT 205 DATE OCT 1994 24.. . NOV 09. .. DEC 02. .. JAN 1995 27. .. FEB 27.. . APR 21.. . JDN 16.. . AUG 19.. . 25.. . SEP 06.. . 06. . . 09.. . 16. .. 17... TIME 0930 1000 1000 0930 0955 0950 1015 1030 0940 0715 0925 0955 0430 0835 STREAM- FLOW, INSTAN- TANEOUS (CFS) 489 142 323 64.0 125 18.0 139 1690 300 2890 3610 184 2290 1590 SEDI- MENT, SUS- PENDED (MG/L) 302 351 1840 317 213 221 411 3060 727 5950 2110 279 1650 1000 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 399 135 1600 55 72 11 154 14000 589 46400 20600 139 10200 4290 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 93 99 91 98 99 99 98 93 99 86 88 99 88 94 206 RIO GRANDS DE LOIZA BASIN 50053025 RIO TURABO ABOVE BORINQUEN, PR LOCATION. --Lat 18°09'35", long 66°02'26", Hydrologic Unit 21010005, on left bank at Highway 765, 1.2 mi (1.9 km) south of Villa Borinquen, 8.1 mi (13.0 km) upstream from Rio Grande de Loiza. DRAINAGE AREA.--7.14 mi 1 (18.49 km'). WATER-DISCHARGE RECORDS PERIOD OP RECORD.--January 1990 to current year. GAGE.—Water-stage recorder and crest-stage gage. 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY NOV DEC JAN MAR APR MAY JUL AUG 1 7.1 11 2 6.7 10 3 7.6 10 4 7.5 10 5 7.2 10 6 6.5 e54 7 8.1 e28 8 7.4 e56 9 6.5 e27 10 6.8 e35 11 7.0 e23 12 6.3 e!5 13 5.6 15 14 6.6 15 15 6.7 15 16 5.4 16 17 6.0 14 18 e24 14 19 e!7 13 20 elO 13 21 e!5 13 22 ell8 13 23 e287 12 24 e271 12 25 e65 13 26 e30 e20 27 e21 e!9 28 e!6 e28 29 e!5 e!4 30 e!3 e25 31 12 - — TOTAL 1029.0 573 MEAN 33.2 19.1 MAX 287 56 MIN 5.4 10 MED 7.6 14 AC-PT 2040 1140 CFSM 4.65 2.68 IN. 5.36 2.99 e30 e86 e!6 e!4 13 11 11 9.8 12 12 13 13 12 12 16 11 10 10 10 9.9 9.5 9.5 9.6 9.5 9.0 8.8 8.6 9.0 8.8 8.7 8.7 431.4 13.9 86 8.6 10 856 1.95 2.25 STATISTICS OP MONTHLY MEAN DATA MEAN 22.7 23.3 MAX 48.2 37.9 (WY) 1991 1992 MIN 10.3 18.7 (WY) 1994 1991 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC- FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 15.5 23.1 1991 10.6 1994 FOR 8.9 8.7 8.9 9.2 9.4 9.4 9.3 9.3 9.4 9.2 9.4 14 9.8 8.5 8.3 7.7 7.3 6.9 7.0 7.0 6.9 7.0 6.8 6.5 6.8 40 14 22 12 10 9.1 318.7 10.3 40 6.5 9.1 632 1.44 1.66 8.3 8.1 7.7 7.4 7.4 7.1 8.9 9.0 7.4 8.4 8.2 7.8 6.6 6.2 6.2 8.2 11 7.4 7.8 10 149 25 18 11 79 168 62 27 ___ ___ ___ 698.1 24.9 168 6.2 8.2 1380 3.49 3.64 FOR WATER YEARS 1990 17.9 47.5 1992 7.85 1990 15.3 24.9 1995 8.93 1990 19 14 11 15 22 12 12 13 13 10 9.4 12 13 34 15 12 12 12 11 11 10 9.8 9.6 9.3 8.8 8.3 8.2 7.8 7.1 6.9 6.9 375.1 12.1 34 6.9 11 744 1.69 1.95 - 1995 10.4 12.1 1995 7.35 1993 1994 CALENDAR YEAR 5130.9 14.1 287 3.3 3.8 10180 1.97 26.73 20 7.7 4.5 Oct 23 Aug 17 Aug 11 6.3 6.6 6.3 6.1 7.0 6.5 8.2 6.6 6.0 5.7 5.9 13 7.2 6.5 12 11 7.9 7.1 6.9 6.8 6.3 6.4 6.2 6.0 5.9 5.8 5.7 5.9 5.6 5.5 208.9 6.96 13 5.5 6.3 414 .98 1.09 5.3 5.1 5.2 5.1 6.9 6.9 7.1 14 10 6.7 6.1 5.6 5.5 5.2 5.7 6.1 5.8 5.5 6.0 6.0 6.2 5.8 5.4 5.8 5.5 5.7 5.9 6.7 9.3 33 14 233.1 7.52 33 5.1 5.9 462 1.05 1.21 9.3 78 130 23 15 12 11 9.0 7.7 7.6 8.6 8.1 7.7 7.8 16 13 15 8.9 7.6 7.1 8.1 7.2 6.4 6.1 5.6 5.6 9.2 7.0 5.3 5.1 --- 468.0 15.6 130 5.1 8.1 928 2.18 2.44 5.0 4.8 4.6 5.5 7.5 5.8 5.7 6.1 5.3 5.0 4.8 7.5 4.4 4.2 4.8 6.5 6.1 6.4 5.5 4.8 5.2 5.7 7.7 8.3 5.6 4.8 6.5 29 18 36 24 261.1 8.42 36 4.2 5.7 518 1.18 1.36 13 12 40 18 12 11 9.9 10 9.6 8.3 7.9 8.2 7.9 7.7 8.2 8.1 8.3 21 126 91 40 33 36 33 64 38 27 26 26 20 16 797.1 25.7 126 7.7 16 1580 3.60 4.15 13 11 8.2 8.8 e80 e730 e!40 129 37 23 20 20 16 13 235 480 421 156 54 45 49 31 101 39 28 24 36 22 179 44 3193.0 106 730 8.2 38 6330 14.9 16.64 , BY WATER YEAR (WY) 7.81 10.7 1993 6.18 1990 FOR 1995 8586. 23. 730 4. 5. 1170 11. 3. 17030 3. 44. 36 9. 5. 15.9 31.9 1993 6.11 1994 WATER YEAR 5 5 Sep 6 2 Jul 14 1 Jul 9 Sep 17 10 Sep 17 7 Jul 30 29 74 4 7 22.7 48.9 1992 9.59 1991 21.2 54.6 1993 8.42 1995 WATER 19 24 12 730 3 3 12000 21 3 14220 2 37 30 9 5 18.3 25.7 1995 6.98 1994 YEARS 1990 .6 .0 .1 Sep .3 Aug . 8 Aug Jan .07 Jan .3 Aug .75 .36 .8 .6 35.2 106 1995 14.1 1990 - 1995 1992 1994 6 1995 17 1994 11 1994 5 1992 5 1992 7 1994 e Estimated RIO GRANDE DE LOIZA BASIN 50053025 RIO TURABO ABOVE BORINQDEN, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Nater years 1990 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: January 1990 to September 1995. INSTRUMENTATION.-- Automatic sediment sampler since 1990. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis and during high flow events. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1030 mg/L July 11, 1994; Minimum daily mean, 1 mg/L Several days. SEDIMENT LOADS: Maximum daily mean, 4,920 tons (4,460 tonnes) Jan. 05, 1992; Minimum daily mean, 0.01 ton (0.01 tonne) Several days. EXTREMES FOR CURRENT YEAR 1995. SEDIMENT CONCENTRATION: Maximum daily mean, 864 mg/L September 17, 1995; Minimum daily mean, 4 mg/L Several days. SEDIMENT LOADS: Maximum daily mean, 1,300 tons (1,180 tonnes) September 17, 1995; Minimum daily mean, 0.06 ton (0.05 tonne) October 13,16,17, 1994. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), NATBR YEAR OCTOBER 1994 TO SEPTEMBER 1995 207 MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCBN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL 7.1 6.7 7.6 7.5 7.2 6.5 8.1 7.4 6.5 6.8 7.0 6.3 5.6 6.6 6.7 5.4 6.0 e24 e!7 elO e!5 elie e287 e271 e65 e30 e21 e!6 e!5 e!3 12 1029.0 6 10 16 15 11 9 12 19 25 16 e 55 21 19 26 52 549 360 74 64 95 100 102 100 70 ___ . . . . . . e6. el. e. el. e36 e721 e372 e!3 e6. e5. e4. e3. e3. 2. 1190. 12 18 32 30 21 15 26 37 45 29 16 08 06 07 07 06 06 5 2 54 5 7 2 3 9 5 2 75 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) NOVEMBER 11 10 10 10 10 e54 e29 e56 e27 e35 e23 el5 15 15 15 16 14 14 13 13 13 13 12 12 13 e20 e!9 e28 e!4 e25 —— 573 45 29 19 13 11 422 51 96 29 51 31 9 9 12 12 11 12 13 14 16 16 17 17 17 18 20 22 25 28 32 --- 1.4 .82 .51 .34 .31 e292 e3.8 e36 e2.4 e9.3 e2.1 e.38 .37 .48 .50 .46 .45 .50 .50 .53 .58 .59 .56 .56 .61 e.64 el. 2 el. 6 el. 5 el. 7 --- 361.91 e30 e96 e!6 el4 13 11 11 9. 12 12 13 13 12 12 16 11 10 10 10 9. 9. 9. 9. 9. 9. 8. 8. 9. 8. 8. 8. 431. DECEMBER 8 9 5 5 6 5 0 8 6 0 e 7 7 4 38 85 63 24 34 31 23 17 ie 21 23 16 10 7 6 7 7 10 14 20 15 8 11 18 14 11 12 15 18 21 24 ___ e2.9 el4 e9.9 e.97 1.1 .88 .66 .49 .58 .68 .84 .56 .33 .22 .27 .20 .20 .28 .38 .52 .38 .22 .28 .44 .33 .25 .28 .36 .43 .50 .56 38.89 e Estimated 208 RIO GRANDB DE LOIZA BASIN 50053025 RIO TDRABO ABOVE BORINQQEN, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MO/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 16 19 20 21 22 23 24 25 26 27 28 29 30 31 8.9 8.7 8.9 9.2 9.4 9.4 9.3 9.3 9.4 9.2 9.4 14 9.8 8.5 8.3 7.7 7.3 6.9 7.0 7.0 6.9 7.0 6.8 6.5 6.8 40 14 22 12 10 9.1 27 30 27 23 20 14 10 7 9 13 20 30 21 9 8 10 13 17 24 31 30 26 23 21 21 46 17 15 13 42 66 .65 .70 .64 .57 .49 .36 .24 .17 .22 .34 .51 1.2 .57 .20 .19 .22 .26 .33 .45 .59 .57 .49 .42 .38 .38 7.9 .66 .92 .46 1.1 1.6 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) FEBRUARY 8.3 8.1 7.7 7.4 7.4 7.1 8.9 9.0 7.4 8.4 8.2 7.8 6.6 6.2 6.2 8.2 11 7.4 7.8 10 149 25 18 11 79 168 62 27 ___ ___ 49 36 27 21 28 43 61 32 13 13 16 19 23 22 17 14 16 21 27 23 466 225 146 128 226 339 111 43 1.1 .79 .56 .42 .55 .81 1.5 .80 .25 .30 .36 .40 .42 .37 .26 .31 .47 .43 .57 .64 337 16 7.1 4.0 110 370 24 3.1 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MARCH 19 14 11 15 22 12 12 13 13 10 9.4 12 13 34 15 12 12 12 11 11 10 9.8 9.6 9.3 8.6 8.3 8.2 7.8 7.1 6.9 6.9 35 33 31 33 36 39 30 12 12 12 14 17 19 54 15 10 11 13 16 21 29 28 21 15 16 20 25 29 28 25 23 1.9 1.3 .90 1.4 2.1 1.3 .97 .41 .41 .34 .36 .52 .69 6.9 .63 .33 .38 .40 .50 .61 .80 .75 .53 .38 .39 .45 .55 .62 .54 .46 .42 TOTAL 318.7 23.78 698.1 884.53 375.1 28.24 RIO GRANDE DE LOIZA BASIN 50053025 RIO TURABO ABOVE BORINQUEN, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MAY 209 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 6.3 6.6 6.3 6.1 7.0 6.5 8.2 6.6 6.0 5.7 5.9 13 7.2 6.5 12 11 7.9 7.1 6.9 6.8 6.3 6.4 6.2 6.0 5.9 5.8 5.7 5.9 5.6 5.5 APRIL 22 22 22 23 23 23 23 24 24 25 25 26 26 25 31 28 25 23 25 30 35 25 16 11 11 13 15 14 12 11 ___ .38 .40 .38 .37 .43 .41 .52 .43 .39 .38 .40 .88 .50 .45 1.3 .88 .54 .44 .47 .55 .59 .43 .27 .18 .18 .20 .22 .22 .19 .16 5.3 5.1 5.2 5.1 6.9 6.9 7.1 14 10 6.7 6.1 5.6 5.5 5.2 5.7 6.1 5.8 5.5 6.0 6.0 6.2 5.8 5.4 5.8 5.5 5.7 5.9 6.7 9.3 33 14 11 11 11 11 11 11 11 20 14 10 11 12 14 17 20 17 14 12 13 16 19 18 15 14 16 19 24 21 17 43 19 .16 .15 .15 .15 .21 .21 .21 1.0 .42 .19 .18 .18 .21 .24 .31 .29 .22 .17 .21 .26 .32 .27 .22 .21 .23 .30 .38 .38 .41 7.2 .80 MEAN DISCHARGE (CFS) 9.3 78 130 23 15 12 11 9.0 7.7 7.6 8.6 8.1 7.7 7.8 16 13 15 8.9 7.6 7.1 8.1 7.2 6.4 6.1 5.6 5.6 9.2 7.0 5.3 5.1 MEAN CONCEN- TRATION (MG/L) JUNE 12 137 255 31 13 14 19 28 32 34 35 29 23 19 24 22 19 19 19 20 23 28 35 44 56 68 59 46 35 27 SEDIMENT DISCHARGE (TONS/ DAY) .31 95 168 2.0 .54 .47 .57 .67 .65 .69 .81 .63 .48 .39 1.0 .78 .73 .44 .39 .38 .51 .55 .60 .72 .85 1.0 1.4 .88 .51 .37 TOTAL 208.9 13.14 233.1 15.84 468.0 282.32 210 RIO GRANDE DE LOIZA BASIN 50053025 RIO TURABO ABOVE BORINQUEN, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) 5.0 4.8 4.6 5.5 7.5 5.8 5.7 6.1 5.3 5.0 4.8 7.5 4.4 4.2 4.8 6.5 6.1 6.4 5.5 4.8 5.2 5.7 7.7 8.3 5.6 4.8 6.5 29 18 36 24 JULY 20 20 78 66 44 30 23 19 16 17 20 23 26 29 32 25 16 11 11 12 14 16 19 21 25 29 32 57 25 61 36 TOTAL 261.1 --- YEAR e 8586.5 Estimated .27 .26 .97 .97 .88 .47 .36 .31 .22 .23 .26 .47 .31 .33 .42 .43 .27 .19 .16 .16 .20 .25 .39 .48 .37 .37 .56 8.1 1.9 17 2.8 40.36 6969.53 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) AUGUST 13 12 40 18 12 11 9 10 9 8 7 8 7 7 8 8 8 21 126 91 40 33 36 33 64 38 27 26 26 20 16 .9 .6 .3 .9 .2 .9 .7 .2 .1 .3 16 10 74 22 13 15 18 20 13 8 5 5 6 7 8 10 11 24 227 120 62 46 52 48 109 58 40 32 27 24 20 13 1 1 89 32 6 4 5 4 25 6 2 2 2 1 .57 .30 .1 .44 .42 .48 .57 .35 .17 .10 .10 .12 .14 .18 .21 .26 .5 .8 .0 .7 .3 .0 .9 .3 .0 .3 .85 797.1 202.16 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) SEPTEMBER 13 11 8.2 8.8 e80 e730 e!40 129 37 23 20 20 16 13 235 480 421 156 54 45 49 31 101 39 28 24 36 22 179 44 3193.0 17 15 14 13 12 11 177 150 50 15 11 11 12 12 425 597 864 129 12 8 53 51 184 57 25 15 41 24 351 67 .58 .43 .30 .30 e.94 e8.6 e!50 62 5.4 .98 .60 .61 .50 .42 679 1100 1300 79 1.7 .96 11 4.6 102 6.2 1.9 .99 11 1.4 358 8.2 3897.61 RIO GRANDE DE LOIZA BASIN 50053025 RIO TURABO ABOVE BORINQUEN, PR—Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT 277 DATE OCT 1994 22. .. 22. .. NOV 06. .. SEP 1995 15... DATE OCT 1994 22... 22. . . NOV 06. .. SEP 1995 15. .. TIME 1930 2000 1225 1527 SED. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 87 86 81 78 DIS- CHARGE, INST. CUBIC FEET PER SECOND 45 234 468 830 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 89 90 87 86 SEDI- MENT, SUS- PENDED (MG/L) 3101 2930 9086 3865 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 98 99 99.5 92 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 376 1850 11500 8660 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 99 99.6 99.8 98.7 SED. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 65 64 49 52 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 99.7 99.8 99.9 99.5 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 69 72 56 60 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99.8 99.9 99.9 99.7 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 75 76 69 66 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 99.9 100 100 99.9 272 RIO GRANDE DE LOIZA BASIN 50053025 RIO TURABO ABOVE BORINQUEN, PR—Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT OCT 1994 27. .. NOV 06.. . JAN 1995 17.. . JUN 02.. . 03... AUG 23. .. SEP 07.. . 07.. . 15.. . 15... 15.. . 22. . . TIME 1652 1325 1242 1112 0442 1640 1612 2337 1442 1647 1837 1300 STREAM- PLOW, INSTAN- TANEOUS (CPS) SEDI- MENT, SUS- PENDED (MG/L) SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 19 206 7.3 266 354 58 301 476 439 460 S14 31 98 923 13 5S1 162 1550 494 1030 2000 1090 3190 25S 513 0.2 417 155 243 401 1320 2370 1350 7010 21 90 99 SO 96 95 95 98 98 99 98 91 96 213 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR LOCATION.--Lat 18°14'33", long 66°00'34», Hydrologic Unit 21010005, on right bank 250 ft (76 m) upstream from bridge on Highway 189, 1.2 mi (1.9 km) downstream from Rio Turabo, and 1.8 mi (2.9 km) east of Plaza de Caguas. DRAINAGE AREA.--89.8 mi 2 (232.6 km2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.—1959 (low-flow measurement only), February to November 1959 (monthly measurements only). December 1959 to current year. GAGE.—Water-stage recorder. Datum of gage is 143.28 ft (43.672 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES NOV MAY JUN JUL SEP 1 45 e86 2 43 681 3 38 676 4 35 e98 5 33 108 6 32 420 7 34 317 8 41 296 9 37 277 10 41 200 11 37 245 12 37 124 13 37 98 14 e34 84 15 e37 77 16 e35 77 17 e32 72 18 154 72 19 90 65 20 90 68 21 53 71 22 170 71 23 1070 76 24 1670 63 25 742 75 26 367 108 27 169 213 28 125 94 29 105 135 30 e98 164 31 e90 --- TOTAL 5621 4011 MEAN 181 134 MAX 1670 420 MIN 32 63 AC-FT 11150 7960 CFSM 2.02 1.49 IN. 2.33 1.66 STATISTICS OF MONTHLY MEAN MEAN 361 320 MAX 1910 1131 (WY) 1971 1988 MIN 44.2 64.9 (WY) 1968 1968 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 191 840 274 198 146 119 112 110 89 79 96 101 86 82 el80 89 69 66 65 62 61 62 74 66 66 62 62 61 55 51 49 3723 120 840 49 7380 1.34 1.54 DATA 226 714 1988 33.6 1968 FOR 50 51 54 56 49 49 45 44 46 51 46 57 69 50 49 46 42 42 40 39 39 38 36 36 37 189 122 83 70 52 42 1719 55.5 189 36 3410 .62 .71 FOR WATER 143 559 1992 45.3 1968 39 37 38 38 34 31 31 52 43 51 40 41 35 31 30 35 53 48 58 63 536 247 101 75 577 627 293 198 ___ --- 3482 124 627 30 6910 1.38 1.44 YEARS 1960 108 291 1984 35.6 1968 162 e!40 el!6 el30 e240 e!80 114 126 128 104 80 78 85 116 83 64 55 50 47 45 42 40 39 37 33 32 32 31 30 28 28 2515 81.1 240 28 4990 .90 1.04 - 1995 91.2 306 1989 23.2 1968 1994 CALENDAR YEAR 36386 99. 4590 18 20 72170 1. 15. 152 53 24 7 Sep 20 Jul 15 JUl 11 11 07 28 27 27 27 27 32 33 40 29 28 27 75 55 36 31 50 42 30 29 27 26 24 22 22 23 21 21 21 19 19 --- 918 30.6 75 19 1820 .34 .38 20 20 19 19 20 26 32 56 114 45 30 26 23 40 29 71 37 26 25 40 44 33 28 26 25 25 22 26 41 95 189 1272 41.0 189 19 2520 .46 .53 121 508 1060 337 161 103 83 70 50 43 62 48 38 34 244 277 177 91 62 60 90 62 47 39 35 80 50 68 38 e36 --- 4174 139 1060 34 8280 1.55 1.73 e32 e32 e26 e27 e70 e52 e50 e52 e47 e37 e34 e74 e96 e!07 el45 el90 el23 elOO e84 e54 e52 e92 e86 e84 e66 51 1370 603 288 248 433 4805 155 1370 26 9530 1.73 1.99 164 126 539 211 119 91 73 89 98 69 63 53 48 45 51 41 46 479 e!230 e600 e272 437 208 212 474 199 145 112 130 92 84 6600 213 1230 41 13090 2.37 2.73 76 68 71 59 115 3680 926 730 271 179 171 222 150 113 1020 3800 2100 704 363 368 383 252 313 261 191 190 176 169 422 216 —— 17759 592 3800 59 35220 6.59 7.36 , BY WATER YEAR (WY) 89.0 355 1978 30.6 1995 FOR 1995 56599 155 3800 19 19 13700 15 19 112300 1 23 290 65 28 240 863 1985 33.7 1974 WATER YEAR Sep 16 Apr 29 Apr 29 Sep 6 .60 Sep 6 Apr 30 .73 .45 244 1283 1979 34.1 1975 225 660 1961 21.8 1974 WATER 214 526 82 17900 11 11 71500 31 17 155200 2 32 353 105 38 252 949 1979 51.4 1994 YEARS 1960 .3 Oct Apr Apr Sep . 17 Sep Aug .39 .42 265 764 1979 37.4 1967 - 1995 1979 1967 9 1970 8 1968 8 1968 6 1960 6 1960 18 1994 e Estimated 274 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1959 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1983 to September 1995. INSTRUMENTATION.— USD-49 sediment sampler since October 1983. Sediment pumping sampler since 1984. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean,14,500 mg/L Nov 27, 1987; Minimum daily mean, 8 mg/L January 23, 1992. SEDIMENT LOADS: Maximum daily mean, 227,000 tons (205,890 tonnes) Nov 27, 1987; Minimum daily mean, 0.65 tons (0.59 tonnes) May 25,1995. EXTREMES FOR CURRENT YEAR.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,710 mg/L September 16, 1995 ; minimum daily mean, 9 mg/L October 5, 1994. SEDIMENT LOADS: Maximum daily mean, 21,500 tons (19,500 tonnes) September 16, 1995; minimum-daily 0.65 ton (0.59 tonnes) May 25,1995. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 12... DEC 15... FEB 1995 09. .. APR 11. .. JtJN 09. .. AUG 14... DATE OCT 1994 12. .. DEC 15. .. FEB 1995 09. .. APR 11. .. JUN 09... AUG 14. .. TIME 1000 0800 0820 0820 0745 0820 HARD- NESS TOTAL (MG/L AS CAC03) 80 -- -- 72 -- 78 DIS- CHARGE, INST. CUBIC FEET PER SECOND 38 154 44 27 53 45 CALCIUM DIS- SOLVED (MG/L AS CA) 21 -- -- 18 -- 21 SPE- CIFIC CON- DUCT- ANCE (US /CM) 263 240 364 305 274 232 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 6.7 -- — 6.6 — 6.3 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.2 7.2 7.0 7.0 7.2 7.0 SODIUM, DIS- SOLVED (MG/L AS NA) 24 -- -- 23 -- 23 TEMPER- ATURE WATER (DBG C) 28.0 25.0 23.0 25.0 27.0 28.0 SODIUM AD- SORP- TION RATIO 1 — — 1 -- 1 TUR- BID- ITY (NTU) 53 160 26 8.1 6.8 14 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.6 -- -- 1.9 -- 2.3 OXYGEN, DIS- SOLVED (MG/L) 6.6 6.6 4.4 5.2 6.3 3.2 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 82 69 89 80 81 82 OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 83 77 50 62 79 41 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 10 12 11 <10 12 10 SULFATE DIS- SOLVED (MG/L AS SO4) 16 — -- 14 -- 12 COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 2900 K7400 K6400 3600 470 3000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 22 -- -- 24 -- 22 STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 5500 K1700 330 2000 390 280 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.20 -- -- 0.10 -- 0.10 K = non-ideal count DATE OCT 1994 12. .. DEC 15. .. FEB 1995 09. .. APR 11. .. JUN 09... AUG 14. .. DATE OCT 1994 12. .. DEC 15. .. FEB 1995 09. . . APR 11. .. JUN 09... AUG 14... RIO GRANDB DB LOIZA BASIN 50055000 RIO GRANDB DE LOIZA AT CAGUAS, PR—Continued WATER-QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 215 SILICA, DIS- SOLVED (MG/L AS SI 02) 34 — — 33 — 35 COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) SOLIDS , SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 176 -- -- 169 -- 171 IRON, TOTAL RECOV- ERABLE (UG/L AS FE) SOLIDS, DIS- SOLVED (TONS PER DAY) 18.1 — — 12.5 — 20.8 LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) RESIDUE TOTAL AT 105 DBG. C, SUS- PENDED (MG/L) 69 188 30 16 14 17 MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS HN) NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.40 0.30 0.40 0.40 0.36 0.30 MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) PHOS- PHORUS TOTAL (MG/L AS P) 0.150 0.200 0.180 0.100 0.130 0.210 SELE- NIUM, TOTAL (UG/L AS SE) ARSENIC TOTAL (UG/L AS AS) 1 — — <1 — — SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) BORON, TOTAL RECOV- ERABLE (UG/L AS B) 30 — -- 30 — — CYANIDE TOTAL (MG/L AS CN) CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- PHENOLS TOTAL (UG/L) CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 — — <1 -- -- MBTHY- LENB BLUB ACTIVE SUB- STANCE (MG/L) 3000 540 290 210 <0.10 <0.10 20 <0.010 <0.010 <0.02 0.03 216 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGDAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) OCTOBER 1 2 3 4 5 6 7 e 9 10 11 12 13 14 15 16 17 IS 19 20 21 22 23 24 25 26 27 28 29 30 31 45 43 38 35 33 32 34 41 37 41 37 37 37 e34 e37 e35 e32 154 90 90 53 170 1070 1670 742 367 169 125 105 e98 e90 45 34 22 14 9 13 25 44 54 60 66 71 49 29 19 41 103 133 78 73 48 148 757 903 441 230 105 78 46 32 24 5. 3. 2. 1. 1. 2. 4. 5. 6. 6. 7. 5. e2. el. e4. e9. 57 19 19 7. 166 2680 4860 1300 282 48 27 13 e8. e7. 5 9 2 3 82 1 3 9 4 6 5 0 0 8 9 0 9 0 6 0 NOVEMBER e86 e81 e76 e98 108 420 317 296 277 200 245 124 98 84 77 77 72 72 65 68 71 71 76 63 75 108 213 94 135 164 ___ 18 14 12 32 164 296 247 224 236 152 203 83 50 35 26 38 33 23 17 21 30 43 60 56 61 77 208 87 83 123 ___ e5. e3. e2. e!3 48 619 222 253 200 110 146 28 13 7. 5. 7. 6. 4. 2. 3. 5. 8. 12 9. 13 23 136 23 32 54 -- 9 4 4 9 3 8 5 5 9 8 8 2 5 - MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) - (MG/L) (TONS/DAY) DECEMBER 191 840 274 198 146 119 112 110 89 79 96 101 86 82 elSO 89 69 66 65 62 61 62 74 66 66 62 62 61 55 51 49 109 644 209 147 103 99 110 91 80 56 71 78 42 22 92 103 75 55 42 31 24 22 21 21 18 16 14 13 15 19 23 84 1550 161 79 41 32 33 27 19 12 20 22 9. 4. e34 25 15 10 7. 5. 3. 3. 4. 3. 3. 2. 2. 2. 2. 2. 3. 7 9 3 2 9 7 2 8 2 7 4 1 2 6 1 TOTAL 5621 9564.72 4011 2018.9 3723 2225.0 e Estimated RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGDAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 217 DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) JANUARY 50 51 54 56 49 49 45 44 46 51 46 57 69 50 49 46 42 42 40 39 39 38 36 36 37 189 122 83 70 52 42 23 21 20 19 18 18 17 16 15 15 14 36 56 34 23 18 14 11 11 11 12 15 20 25 40 138 182 121 91 70 54 3 2 2 2 2 2 2 1 1 2 1 6 11 4 3 2 1 1 1 1 1 1 1 2 4 98 62 27 17 10 6 .1 .9 .9 .9 .4 .3 .0 .9 .9 .0 .8 .0 .6 .0 .2 .6 .2 .1 .2 .3 .6 .9 .4 .0 .2 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) FEBRUARY 39 37 38 38 34 31 31 52 43 51 40 41 35 31 30 35 53 48 58 63 536 247 101 75 577 627 293 198 42 34 29 27 46 83 125 58 31 41 20 16 16 17 17 28 41 27 31 44 339- 248 96 82 322 482 249 164 4. 3. 3. 2. 4. 6. 11 7. 3. 6. 2. 1. 1. 1. 1. 2. 6. 3. 4. 7. 942 183 27 17 1590 1080 220 94 4 5 0 8 2 9 8 6 0 2 8 6 4 4 8 0 5 9 8 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MARCH 162 el40 el!6 e!30 e240 elSO 114 126 128 104 80 78 85 116 83 64 55 50 47 45 42 40 39 37 33 32 32 31 30 28 28 166 76 64 60 114 83 99 77 89 47 24 21 58 84 29 17 17 18 20 21 21 21 17 13 11 13 16 22 28 32 34 78 e25 e22 e20 e58 e28 32 27 31 13 5. 4. 14 26 6. 2. 2. 2. 2. 2. 2. 2. 1. 1. 1. 1. 1. 2. 2. 2. 2 3 7 8 6 5 6 6 4 2 8 3 96 1 4 8 2 4 5 1719 289.4 3482 4239.6 2515 423.36 e Estimated 218 RIO GRANDE DB LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAO0AS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 )AY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MEAN DISCHARGE (CPS) 28 27 27 27 27 32 33 40 29 28 27 75 55 36 31 50 42 30 29 27 26 24 22 22 23 21 21 21 19 19 ___ MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) APRIL MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MAY MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) JUNE 28 27 27 27 27 32 33 40 29 28 27 75 55 36 31 50 42 30 29 27 26 24 22 22 23 21 21 21 19 19 35 29 23 18 15 26 30 25 14 15 15 31 51 24 12 28 38 20 12 12 14 16 16 16 17 17 20 26 32 37 2.7 2.1 1.7 1.3 1.1 2.2 2.7 2.8 1.1 1.1 1.1 7.3 8.1 2.3 1.0 4.6 4.3 1.6 .92 .90 .97 1.0 .96 .97 1.0 .97 1.1 1.4 1.7 2.0 20 20 19 19 20 26 32 56 114 45 30 26 23 40 29 71 37 26 25 40 44 33 28 26 25 25 22 26 41 95 189 43 49 55 55 52 49 39 50 109 84 66 51 40 40 28 58 32 22 15 20 33 22 15 10 10 11 12 19 36 81 133 2 2 2 2 2 3 3 12 34 10 5 3 2 5 2 12 3 1 1 2 3 2 1 1 4 28 76 .3 .6 .8 .8 .8 .5 .4 .3 .6 .4 .0 .5 .3 .6 .0 .6 .9 .0 .1 .72 .65 .72 .74 .4 .1 121 508 1060 337 161 103 83 70 50 43 62 48 38 34 244 277 177 91 62 60 90 62 47 39 35 80 50 68 38 e36 85 344 680 223 159 113 27 21 22 24 50 42 24 17 165 189 121 80 60 52 42 24 33 42 37 55 46 37 17 15 30 597 2310 209 70 31 6 4 2 2 9 5 2 1 128 142 59 20 10 9 11 4 4 4 3 17 6 7 1 1 .1 .0 .9 .7 .5 .5 .5 .6 .8 .0 .2 .5 .6 .3 .5 .7 .5 TOTAL 918 62.99 1272 234.83 4174 3711.9 e Estimated RZO GRANDB DE LOIZA BASIN 219 50055000 RZO GRANDB DE LOIZA AT CAQUAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR e Estii «32 •32 •26 •27 •70 •52 •50 •52 •47 •37 •34 •74 •96 • 107 • 145 • 190 • 123 • 100 • 84 • 54 •52 •92 • 86 • 84 •66 51 1370 603 288 248 433 4805 56599 Dated JULY 14 16 18 22 39 29 21 24 28 31 27 23 21 26 32 75 159 162 151 102 48 56 65 73 70 64 743 376 272 155 317 —— MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) AUGUST • 1 el • 1 •1 •5 •4 •2 •3 •3 •3 •2 •3 •4 •7 • 11 •35 • 65 •49 • 37 • 19 •6 • 11 • 16 • 17 • 12 8 5280 684 241 140 430 7109 87936. .3 .4 .4 .6 .0 .8 .9 .4 .7 .5 .6 .2 .9 .1 .9 .8 .5 90 164 126 539 211 119 91 73 89 98 69 63 53 48 45 51 41 46 479 •1230 •600 •272 437 208 212 474 199 145 112 130 92 84 6600 126 100 316 174 82 49 35 52 36 25 38 49 40 38 43 37 45 197 748 202 252 312 146 256 327 123 52 29 97 50 22 —— 57 34 532 105 27 12 6. 12 9. 4. 6. 7. 5. 4. 6. 4. 5. 545 •3050 • 194 •244 446 82 143 522 69 21 8. 36 13 5. 6218. 9 7 7 6 0 2 6 0 1 6 7 1 2 MEAN DISCHARGE (CPS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) SEPTEMBER 76 68 71 59 115 3680 926 730 271 179 171 222 150 113 1020 3800 2100 704 363 368 383 252 313 261 191 190 176 169 422 216 --- 17759 26 45 79 119 96 728 419 571 186 114 89 143 44 14 406 1710 1070 105 35 144 74 23 132 124 16 50 145 134 336 197 --- —— 5.3 8.3 15 19 37 14700 1680 1370 139 56 42 91 18 4.3 3300 21500 7300 268 34 177 77 15 139 97 8.6 30 69 61 460 118 --- 51838.5 220 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE OE LOIZA AT CAGUAS, PR--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT SED. SED. SED. DIS- SEDI- SUSP. SUSP. SUSP. DATE OCT 1994 23. .. NOV 30. .. JUN 1995 03. .. AUG 19. .. 19... SEP 06. .. TIME 0640 1700 1050 1224 1525 1511 CHARGE, INST. CUBIC FEET PER SECOND 2630 146 1367 «1530 «1317 3175 SEDI- MENT, SUS- PENDED (MG/L) 1567 693 13S1 1116 105S 1362 . MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 11100 273 5100 «4610 «3760 11700 FALL DIAM. PERCENT FINER THAN .002 MM 68 90 65 67 56 58 FALL DIAM. PERCENT FINER THAN .004 MM 71 89 67 76 64 58.1 FALL DIAM. PERCENT FINER THAN .008 MM 81 96 83 82 73 68.1 DATE OCT 1994 23. .. NOV 30. . . JUN 1995 03. .. AUG 19. .. 19. .. SEP 06. .. SED. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 89 93 90 88 79 77 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM -- 97 94 86 85 83 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 99.4 99.7 98.9 98 97 97 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 99.7 99.9 99.8 99.5 99 99 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 99.8 99.9 99.9 99.8 99.5 99.6 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 1 99.9 100 100 100 99.7 99.8 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .00 MM 100 100 100 100 100 100 e Estimated RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT 221 DATE OCT 1994 22.. . 23.. . 26. . . DEC 02.. . 02. .. 03.. . MAR 1995 01.. . MAY 10.. . OUN 17... OUL 27.. . 27.. . 27. .. AUG 03.. . 19.. . SEP 06.. . 28.. . TIME 2332 0717 1802 0904 1049 1610 1720 1720 1000 1027 1620 1727 1555 1331 1549 1631 STREAM- PLOW, INSTAN- TANEOUS (CPS) 1470 2213 253 1500 1510 317 112 36 196 3284 2187 1920 765 e2086 2800 155 SEDI- MENT, SUS- PENDED (MG/L) 489 1460 110 895 932 167 140 80 126 2380 995 924 371 363 496 901 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 1940 8720 75 3620 3800 143 42 7.8 67 21100 5870 4790 766 e2040 3750 377 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 95 97 98 95 98 99 92 96 93 99 98 98 99 93 98 99 e Estimated 222 RIO GRANDE DE LOIZA BASIN 50055100 RIO CAGUITAS NEAR AGUAS BUENAS, PR LOCATION.--Lat 18°14'48", long 66°05'37'', Hydrologic Unit 21010005, on right bank 450 ft (137 m) upstream from bridge on Highway 777, 1.0 mi (1.6 km) southeast from Aguas Buenas, 3.9 mi (6.3 km) northwest from Caguas, and 2.1 mi (3.4 km) southwest from Las Carolinas. DRAINAGE AREA.--5.30 mi j (13.72 km*). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1990 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 394 ft (120 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT JAN FEB APR 1 2.7 2.5 2 2.4 2.4 3 2.4 2.3 4 2.4 2.2 5 2.4 2.2 6 2.4 3.1 7 2.9 2.7 8 3.2 2.6 9 2.6 2.6 10 2.5 3.8 11 2.6 2.7 12 2.5 2.4 13 2.5 2.3 14 2.5 2.2 15 2.5 2.1 16 2.4 2.1 17 2.6 2.1 18 4.4 2.2 19 5.5 2.1 20 4.6 2.1 21 2.9 2.4 22 6.6 2.2 23 14 2.1 24 11 2.0 25 4.1 2.5 26 3.0 2.5 27 2.8 2.3 28 2.8 2.5 29 2.6 7.9 30 2.7 4.6 31 2.6 —— TOTAL 113.1 79.7 MEAN 3.65 2.66 MAX 14 7.9 MIN 2.4 2.0 AC-FT 224 158 CFSM .69 .50 IN. .79 .56 STATISTICS OF MONTHLY MEAN MEAN 9.03 7.89 MAX 20.9 12.3 (WY) 1991 1993 MIN 3.65 2.66 (WY) 1995 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 3.6 4.6 3.2 3.0 3.2 2.9 2.6 2.5 2.4 2.3 2.2 2.2 2.2 2.2 2.1 2.1 2.0 2.0 2.0 1.9 1.9 1.9 1.9 1.9 1.9 1.8 2.0 2.3 1.9 1.9 1.9 72.5 2.34 4.6 1.8 144 .44 .51 DATA 7.27 13.4 1993 2.34 1995 FOR 1.9 1.9 2.1 2.1 1.9 1.9 2.2 2.1 2.3 3.1 2.4 3.7 2.3 2.2 2.1 2.0 2.0 2.0 2.7 2.4 2.0 2.0 2.0 1.9 1.9 7.0 3.0 4.7 2.6 2.3 2.1 76.8 2.48 7.0 1.9 152 .47 .54 FOR WATER 8.28 16.7 1992 2.48 1995 2.0 1.9 1.9 1.8 1.8 1.8 1.8 1.8 1.7 1.7 1.7 1.6 1.7 1.7 1.9 2.0 1.9 1.8 2.0 2.2 6.5 4.0 3.5 4.4 10 6.1 3.8 7.9 ___ --- 82.9 2.96 10 1.6 164 .56 .58 YEARS 1990 5.02 8.00 1991 2.96 1995 3.9 3.2 3.1 3.5 3.2 2.8 2.7 2.9 2.6 2.6 2.9 3.2 5.3 4.7 3.1 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2.1 2.0 2.0 1.8 1.8 1.8 1.7 1.7 1.7 83.1 2.68 5.3 1.7 165 .51 .58 - 1995 5.23 8.87 1990 2.68 1995 1994 CALENDAR YEAR 1267. 3. 14 1. 1. 2510 . 8. 5. 2. 1. 8 47 Oct 23 5 Aug 3 5 Aug 2 66 90 6 9 8 1.7 1.7 1.7 1.6 1.6 1.6 1.8 1,9 1.8 1.7 1.8 3.0 2.0 2.0 2.7 2.7 2.3 1.9 1.9 1.8 1.8 1.8 1.7 1.7 1.7 1.7 1.5 1.4 1.4 1.3 --- 55.2 1.84 3.0 1.3 109 .35 .39 1.5 1.9 2.1 2.2 2.4 3.0 3.1 19 4.0 2.5 2.4 2.4 2.5 e3.6 e6.0 4.6 3.6 3.6 3.7 3.7 3.4 3.3 2.9 2.8 2.8 2.8 2.9 2.9 4.0 6.6 4.0 116.2 3.75 19 1.5 230 .71 .82 3.2 5.8 9.2 3.2 3.7 3.3 3.6 3.6 4.6 4.1 3.7 3.7 3.8 4.8 6.0 5.5 4.5 2.8 2.7 3.8 4.8 3.1 2.9 2.8 2.8 4.0 3.8 3.2 2.7 2.7 —— 118.4 3.95 9.2 2.7 235 .74 .83 2.6 2.5 2.5 2.4 2.4 2.4 2.7 2.3 2.1 1.9 2.3 2.2 2.4 2.5 2.2 2,2 2.2 2.4 2.4 2.3 2.3 7.8 2.6 2.2 2.6 2.9 14 9.0 5.6 3.2 3.0 102.1 3.29 14 1.9 203 .62 .72 2.9 2.9 11 3.2 2.8 2.9 2.8 2.8 2.8 2.9 2.9 2.8 2.9 3.2 3.2 3.6 3.5 53 60 11 6.9 8.8 7.4 7.6 8.3 6.1 5.1 4.2 3.5 3.4 3.3 247.7 7.99 60 2.8 491 1.51 1.74 3.3 3.2 3.1 3.1 7.6 143 29 12 5.7 3.6 3.1 2.9 2.7 2.6 14 118 34 12 7.9 5.8 4.5 3.4 4.2 3.1 2.9 2.9 11 4.6 4.6 3.1 --- 460.9 15.4 143 2.6 914 2.90 3.23 , BY WATER YEAR (WY) 5.41 13.1 1993 1.84 1995 FOR 1995 1608 4 143 1 1 1480 15 1 3190 11 6 2 1 6.41 18.0 1993 2.48 1990 WATER YEAR .6 .41 Sep 6 .3 Apr 30 .5 Apr 25 Sep 6 .29 Sep 6 . 3 Aug 3 .83 .29 .0 .6 .8 4.28 8.05 1993 2.32 1994 6.47 18.6 1993 1.86 1994 WATER 6 11 4 235 1 1 2290 18 1 4940 1 17 9 4 2 6.34 11.2 1993 1.85 1994 YEARS 1990 .81 .1 .41 Jan .3 Apr .5 Apr Sep .28 Sep .3 Aug .29 .47 .5 .6 .2 7.93 15.4 1995 3.32 1994 - 1995 1993 1995 5 1992 30 1995 25 1995 18 1993 18 1993 3 1995 e Estimated tO tO 10 tO tO <J *k |-t *k Ol 10 *k U1 *k tO tO tO 10 tO 10 10 tOtOUtOtO tOtOtOtOtO OOOO OOOOO -J IO IO IO tO 10 10 to tO tO tO tO tO tO W tO tO tO tO (J tO tO tO W K tO tO tO tO tO (-> K tO IO N) N) Co 224 RIO GRANDE DE LOIZA BASIN 50055100 RIO CAGUITAS NEAR AGDAS BUENAS , PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1.9 1.9 2.1 2.1 1.9 1.9 2.2 2.1 2.3 3.1 2.4 3.7 2.3 2.2 2.1 2.0 2.0 2.0 2.7 2.4 2.0 2.0 2.0 1.9 1.9 7.0 3.0 4.7 2.6 2.3 2.1 13 10 11 13 14 16 18 20 13 16 8 18 16 13 12 11 10 9 15 8 6 6 6 6 6 12 9 9 8 8 8 .06 .05 .06 .07 .07 .08 .11 .11 .08 .15 .05 .20 .10 .08 .07 .06 .05 .05 .17 .05 .03 .03 .03 .03 .03 .28 .08 .11 .06 .05 .05 MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) FEBRUARY 2.0 1.9 1.9 1.8 1.8 1.8 1.8 1.8 1.7 1.7 1.7 1.6 1.7 1.7 1.9 2.0 1.9 1.8 2.0 2.2 6.5 4.0 3.5 4.4 10 6.1 3.8 7.9 ___ 9 9 10 10 15 22 31 26 20 15 12 10 8 9 11 13 13 14 14 14 42 22 19 16 303 41 22 56 ___ .05 .05 .05 .05 .07 .10 .15 .13 .09 .07 .05 .04 .04 .04 .05 .07 .07 .07 .08 .08 1.3 .24 .18 .20 26 .70 .23 1.6 ___ ___ MARCH 3.9 3.2 3.1 3.5 3.2 2.8 2.7 2.9 2.6 2.6 2.9 3.2 5.3 4.7 3.1 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2.1 2.0 2.0 1.8 1.8 1.8 1.7 1.7 1.7 22 19 17 26 45 76 86 86 86 87 88 85 50 25 13 11 10 10 12 15 18 15 12 10 9 9 10 10 9 7 6 .23 .16 .15 .25 .38 .57 .63 .66 .61 .61 .68 .74 .71 .32 .11 .08 .07 .07 .08 .09 .11 .09 .07 .05 .05 .05 .05 .05 .04 .03 .03 76.8 2.50 82.9 31.85 83.1 7.82 225 RIO GRANDE DE LOIZA BASIN *• ^ ** 50055100 RIO CAGDITAS NEAR AGUAS BUENAS , PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1.7 1.7 1.7 1.6 1.6 1.6 1.8 1.9 1.8 1.7 1.8 3.0 2.0 2.0 2.7 2.7 2.3 1.9 1.9 1.8 1.8 1.8 1.7 1.7 1.7 1.7 1.5 1.4 1.4 1.3 ___ APRIL 7 8 10 12 14 16 15 15 14 14 13 31 20 10 13 16 12 10 10 11 12 11 10 9 10 12 13 12 10 8 ___ .03 .04 .04 .05 .06 .07 .07 .07 .07 .06 .06 .27 .11 .06 .13 .15 .08 .05 .05 .05 .06 .05 .05 .04 .05 .05 .05 .04 .04 .03 MEAN DISCHARGE (CPS) 1.5 1.9 2.1 2.2 2.4 3.0 3.1 19 4.0 2.5 2.4 2.4 2.5 *3.6 *6.0 4.6 3.6 3.6 3.7 3.7 3.4 3.3 2.9 2.8 2.8 2.8 2.9 2.9 4.0 6.6 4.0 MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) MAY 8 8 8 7 7 7 7 1110 589 23 24 24 22 20 25 27 20 17 17 20 21 21 20 19 16 13 10 10 9 34 29 JUNE .03 .04 .04 .04 .05 .06 .06 163 8.5 .16 .16 .16 .15 e.19 e.47 .36 .20 .16 .18 .20 .20 .19 .16 .14 .12 .10 .08 .08 .10 .87 .32 3.2 5.8 9.2 3.2 3.7 3.3 3.6 3.6 4.6 4.1 3.7 3.7 3.8 4.8 6.0 5.5 4.5 2.8 2.7 3.8 4.8 3.1 2.9 2.8 2.8 4.0 3.8 3.2 2.7 2.7 18 35 70 48 37 35 39 44 49 55 61 55 48 41 36 33 29 27 26 28 39 30 25 24 24 28 33 29 28 48 ___ .15 .57 2.0 .42 .38 .31 .37 .43 .61 .61 .61 .55 .49 .53 .59 .48 .36 .20 .19 .32 .53 .25 .20 .18 .18 .37 .33 .25 .21 .35 ___ TOTAL 55.2 —— 2.03 116.2 —— 176.57 118.4 —— 13.02 e Estimated RIO GRANDE DE LOIZA BASIN 50055100 RIO CAGUITAS NEAR AQUAS BUENAS , PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR MEAN DISCHARGE (CPS) 2.6 2.5 2.5 2.4 2.4 2.4 2.7 2.3 2.1 1.9 2.3 2.2 2.4 2.5 2.2 2.2 2.2 2.4 2.4 2.3 2.3 7.8 2.6 2.2 2.6 2.9 14 9.0 5.6 3.2 3.0 102.1 1608.6 MEAN CONCEN- TRATION (MG/L) JULY 89 110 113 65 35 19 17 18 18 19 20 21 22 24 25 29 34 41 44 46 48 1440 271 67 40 26 126 79 59 53 47 —— SEDIMENT DISCHARGE (TONS/DAY) .62 .74 .77 .43 .23 .12 .12 .11 .11 .10 .12 .13 .15 .16 .15 .17 .21 .27 .29 .29 .31 70 2.0 .39 .29 .20 7.2 3.2 .90 .46 .39 90.63 4709.84 MEAN DISCHARGE (CPS) 2.9 2.9 11 3.2 2.8 2.9 2.8 2.8 2.8 2.9 2.9 2.8 2.9 3.2 3.2 3.6 3.5 53 60 11 6.9 8.8 7.4 7.6 8.3 6.1 5.1 4.2 3.5 3.4 3.3 247.7 MEAN CONCEN- TRATION (MG/L) AUGUST 47 48 1100 98 45 36 28 23 24 27 30 29 26 24 22 20 18 794 1020 151 212 357 305 222 161 112 55 25 11 10 12 —— SEDIMENT DISCHARGE (TONS /DAY) .37 .37 56 .87 .34 .28 .22 .18 .19 .21 .24 .22 .20 .20 .19 .19 .17 331 323 4.9 3.9 8.5 6.0 4.6 3.6 1.9 .76 .29 .11 .09 .10 749.19 MEAN DISCHARGE (CPS) 3.3 3.2 3.1 3.1 7.6 143 29 12 5.7 3.6 3.1 2.9 2.7 2.6 14 118 34 12 7.9 5.8 4.5 3.4 4.2 3.1 2.9 2.9 11 4.6 4.6 3.1 460.9 MEAN CONCEN- TRATION (MG/L) SEPTEMBER 14 14 14 14 46 1620 693 110 29 17 14 12 11 11 410 1730 399 116 42 25 21 24 27 30 33 32 598 42 20 15 --- —— SEDIMENT DISCHARGE (TONS /DAY) .12 .12 .12 .12 1.6 2360 76 4.1 .47 .16 .11 .10 .08 .07 116 910 47 3.9 .90 .40 .26 .23 .31 .25 .26 .25 82 .58 .26 .13 --- 3605.90 RIO GRANDE DE LOIZA BASIN 50055100 RIO CAGOITAS NEAR AGOAS BOENAS, PR--Continued HATER QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT 227 DATE FEE 1995 22. . . MAY 08. .. JOL 22. .. AOG 03. .. SEP 05. .. 06. .. 07. .. 27. .. DATE FEE 1995 22. .. MAY 08... JOL 22. .. AOG 03... SEP 05... 06. .. 07... 27. .. TIME 1527 1622 1332 1100 2252 0751 1701 1652 SED. SOSP. FALL DIAM. PERCENT FINER THAN .016 MM -- 84 85.9 83 79 43 84 90 DIS- CHARGE, INST. CUBIC FEET PER SECOND 3.7 37 39 20 78 902 92 61 SED. SOSP. FALL DIAM. PERCENT FINER THAN .031 MM -- 84 86 84 84 54 85 93 SEDI- MENT, SUS- PENDED (MG/L) 2150 12200 14455 2382 3917 18300 1752 8610 SED. SOSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 99 98 99 97 94 64 98 98.9 SEDI- MENT, DIS- CHARGE, SOS- P ENDED (T/DAY) 21.5 1220 1520 128 825 44600 435 1420 SED. SOSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 99.4 99 99.3 98 96 73 98 99.4 SED. SOSP. FALL DIAM. PERCENT FINER THAN .002 MM 85 47 56 53 39 19 58 64 SED. SOSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 99.6 99.7 99.5 99 98 90 99.2 99.6 SED. SOSP. FALL DIAM. PERCENT FINER THAN .004 MM __ 60 75 73 51 26 69 78 SED. SOSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99.8 99.9 99.7 99.6 99.2 97 99.8 99.8 SED. SOSP. FALL DIAM. PERCENT FINER THAN .008 MM 87 76 85 82 63 33 78 88 SED. SOSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 100 99.9 99.9 99.9 99.7 99 100 100 228 RIO GRANDE DE LOIZA BASIN 50055100 RIO CAGUITAS NEAR AGUAS BUENAS, PR—Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OP SUSPENDED SEDIMENT DATE OCT 1994 18.. . 21.. . 22... 22... MAY 1995 09... JUN 26... JUL 27.. . ADG 18... 18... SEP 06.. . 15.. . 17.. . 27... TIME 1537 1508 2012 2242 1245 1238 1400 1752 1917 0637 2337 1545 1552 STREAM- PLOW, INSTAN- TANEOUS (CPS) 4.9 2.9 33 18 2.9 2.8 29 56 578 52 130 33 71 SEDI- MENT, SUS- PENDED (MG/L) 248 291 1850 291 669 788 535 18100 5080 1460 5470 554 2520 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 3.3 2.3 165 14 5 6 42 2740 7100 205 1920 49 483 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 97 87 88 88 99 98 95 97 83 96 93 98 94 RIO GRANDE DE LOIZA BASIN 50055170 RIO CAGUITAS NEAR CAGUAS, PR LOCATION.--Lat 18°13'59", long 66°02'53", Hydrologic Unit 21010005, on left bank, 0.9 mi (1.4 km) southwest from Plaza de Caguas, 0.6 mi (1.0 km) northeast from Escuela Bunker, and 1.2 mi (1.9 km) northwest from Escuela Antonio S. Pedreira. 229 DRAINAGE AREA.--8.27 mi 1 (21.42 km 2 )- WATER-DISCHARGE RECORDS PERIOD OP RECORD.--May 1992 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 216 ft (66 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY AUG SEP 1 7.0 e5.1 2 6.0 e5.0 3 5.4 e4.7 4 4.7 e4.6 5 4.0 e4.6 6 3.4 e6.2 7 4.0 e5.4 8 7.1 e5.2 9 9.6 e5.2 10 6.7 e7.8 11 5.5 e5.6 12 4.2 e5.0 13 3.6 e4.7 14 3.3 e4.6 15 3.1 e4.3 16 3.1 e4.3 17 3.7 e4.3 18 e8.4 e4.5 19 e6.5 e4.3 20 e!9 e4.3 21 e6.0 e4.8 22 e27 e4.5 23 e45 e4.2 24 e!9 e4.0 25 e8.6 e5.0 26 e6.4 e5.0 27 e5.8 e4.7 28 e5.8 e5.2 29 e5.2 e7.0 30 e5.3 elO 31 e5.2 —— TOTAL 257.6 154.1 MEAN 8.31 5 . 14 MAX 45 10 MIN 3.1 4.0 AC-FT 511 306 CFSM 1.00 .62 IN. 1.16 .69 STATISTICS OF MONTHLY MEAN MEAN 12.6 22.7 MAX 16.0 37.4 (WY) 1994 1993 MIN 8.31 5.14 (WY) 1995 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS e7.2 e9.0 e6.4 e6.0 e6.2 e5.6 e5.0 e4.8 e4.7 e4.6 e4.5 e4.4 e4.4 e4.4 e4.2 e4.1 e4.0 e4.0 e3.8 e3.6 e3.0 e2.8 e2.6 e2.5 e2.4 e2.9 e3.0 e2.6 e2.4 e2.2 e2.0 129.3 4.17 9.0 2.0 256 .50 .58 DATA 16.4 37.0 1993 4.17 1995 FOR el. 9 el. 8 el. 7 el. 6 el. 5 el. 4 el. 4 el. 3 el. 2 e2.5 e3.0 e2.5 e2.2 el. 8 el. 5 el. 4 el. 3 el. 2 el.l el.O el. 8 el. 3 el.O e.90 e.85 e4.7 e5.2 e3.4 e2.5 e2.0 el. 8 58.75 1.90 5.2 .85 117 .23 .26 el. 6 el. 5 el. 3 el. 3 el. 2 el.l el.O .98 .97 .95 .93 .91 .88 .88 .86 .84 .82 .84 .82 .80 e8.0 e7.0 e6.5 e3.5 e2.5 elO e6.0 e4.5 ___ ___ —— 68.48 2.45 10 .80 136 .30 .31 FOR WATER YEARS 1992 9.92 20.0 1993 1.90 1995 6.16 9.20 1993 2.45 1995 e3.2 e3.9 e2.5 e2.2 el. 9 el. 8 el. 6 el. 5 el. 4 el. 4 el. 3 el. 5 e2.5 e6.0 e3.5 e2.5 e2.0 el. 5 el. 3 el. 4 el. 2 el.O .82 .79 .79 .78 .81 .78 .79 .77 .76 54.19 1.75 6.0 .76 107 .21 .24 - 1995 4.45 6.26 1993 1.75 1995 1994 CALENDAR YEAR 2075.45 5.69 78 .76 .83 4120 .69 9.34 8.1 4.5 1.7 Sep 20 Jun 8 Jun 8 .77 .79 .77 .74 .79 .77 .79 .81 .84 .84 .90 3.1 1.8 1.5 2.3 2.8 1.7 el. 5 el. 3 el. 2 el.l el.O .97 .95 .90 .84 .82 .78 .74 .72 34.83 1.16 3.1 .72 69 .14 .16 , BY WATER 11.0 27.8 1993 1.16 1995 FOR 1995 3046. 8. 508 . 1910 24. 6040 1. 13. 8. 2. e.74 e.76 e.82 e.90 el. 2 el. 5 e7.0 e50 elO e4.5 e2.5 e2.0 el. 8 e2.7 e4.0 e3.2 e2.4 e2.4 e2.5 e2.5 e2.3 e2.2 e2.0 el. 9 el. 9 el. 9 e2.0 e2.0 e2.9 e4.4 e2.8 129.72 4.18 50 .74 257 .51 .58 YEAR (WY) 15.9 41.2 1993 2.31 1994 «2.2 e4.1 e6.0 e2.2 e2.6 e2.3 e2.4 e2.4 e3.1 e2.8 e2.5 e2.5 e2.6 e3.3 e3.9 e3.6 e3.1 e2.1 e2.0 e2.8 e3.7 e2.4 e2.2 e2.1 e2.1 e3.0 e2.8 e2.4 e2.0 el. 9 —— 83.1 2.77 6.0 1.9 165 .33 .37 6.65 14.9 1993 1.71 1994 WATER YEAR 57 35 72 77 43 01 70 0 6 89 Sep 6 Apr 30 Apr 27 Sep 6 Sep 6 e2.1 e2.0 el. 9 el. 9 el. 9 el. 9 e2.0 el. 9 el. 8 el. 8 el. 8 el. 9 el. 8 el. 9 el. 8 el. 8 el. 9 el. 8 el. 9 el. 9 e3.0 e6.0 63.0 62.0 62.5 e3.5 elO 65.8 63.7 62.5 62.3 82.0 2.65 10 1.8 163 .32 .37 14.7 45.5 1993 2.65 1995 WATER 13. 24. 8. 508 . . 3010 26. 9950 1. 22. 21 6. 1. e2.2 e2.3 elO e2.5 e2.2 e2.2 e2.3 e2.2 e2.2 62.3 e2.3 e2.4 62.5 62.7 62.9 63.5 63.7 e9.0 e25 elO e7.0 e6.0 e6.4 e6.0 e5.2 e3.8 e3.5 e3.0 e2.8 e2.7 e2.8 143.6 4.63 25 2.2 285 .56 .65 10.3 20.2 1993 4.63 1995 YEARS 1992 7 5 33 Sep 72 Apr 77 Apr Sep 10 Sep 66 57 6 7 e2.7 e2.6 e2.6 62.5 elOO 508 250 182 e!25 e70 e30 e20 e 15 elO e8. 0 275 74 e35 e 18 e!3 elO e8.0 e7.0 e6.6 e6.5 e6.4 e35 e!4 e8. 0 e6.0 1850.9 61.7 508 2.5 3670 7.46 8.33 29.4 61.7 1995 12.3 1994 - 1995 1993 1994 6 1995 30 1995 27 1995 18 1983 18 1983 e Estimated 230 RIO GRANDE DE LOIZA BASIN 50055170 RIO CAGDITAS NEAR CA6DAS, PR--Continued WATER-QUALITY RECORDS PERIOD OP RECORDS.— Water years 1992 to current year. PERIOD OP DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: June 1992 to September 1995. INSTRUMENTATION.-- Automatic sediment sampler since 1992. REMARKS.-- Sediment Samples were collected by a local observer on a weekly basis and during high flow event* EXTREMES POR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,960 mg/L September 06, 1995; Minimum daily mean, 1 mg/L July 16-19, 1994. SEDIMENT LOADS: Maximum daily mean,14,000 tons (12,700 tonnes) December 26, 1992; Minimum daily mean, eO.Ol ton (eO.Ol tonne) several days. EXTREMES POR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATION: Maximum daily 4 mg/L July 12-13, 1995. »an, 2,960 mg/L September 06, 1995; Minimum daily mean. SEDIMENT LOADS: Maximum daily mean, 6,640 tons (6,170 tonnes) September 06, 1995; Minimum daily mean, eO.Ol ton (eO.Ol tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) )AY 1 2 3 4 5 6 7 6 9 10 11 12 13 14 15 16 17 16 19 20 21 22 23 24 25 26 27 28 29 30 31 MEAN DISCHARGE (CPS) 7.0 6.0 5.4 4.7 4.0 3.4 4.0 7.1 9.6 6.7 5.5 4.2 3.6 3.3 3.1 3.1 3.7 e6.4 e6.5 e!9 e6.0 e27 e45 el9 eB.6 e6.4 e5.6 e5.B e5.2 e5.3 e5.2 OCTOBER 11 11 16 15 14 13 9 13 22 24 16 15 22 27 26 20 16 32 30 103 7 52 102 55 13 11 15 20 19 11 15 .20 .17 .23 .20 .15 .12 .10 .26 .56 .43 .24 .16 .21 .24 .22 .16 .16 e.69 ell TOTAL 257.6 e.07 e21 e22 e2.1 e.23 e.19 e.25 e.31 e.26 e.16 e.22 63.46 MEAN DISCHARGE (CPS) e5.1 e5.0 e4.7 e4.6 e4.6 e6.2 e5.4 e5.2 e5.2 e7.6 e5.6 e5.0 e4.7 e4.6 e4.3 e4.3 e4.3 e4.5 e4.3 e4.3 e4.6 e4.5 e4.2 e4.0 e5.0 e5.0 e4.7 e5.2 e7.0 elO ._- MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) NOVEMBER 13 .16 10 6 6 9 6 11 24 19 14 16 33 32 13 10 11 15 19 24 22 20 20 20 19 19 19 19 19 16 16 .13 .10 .11 .11 .12 .17 .34 .27 .24 .29 .46 .43 .16 .11 .13 .17 .23 .26 .26 .25 .25 .23 .22 .23 .26 .25 .25 .30 .41 ___ --- MEAN DISCHARGE (CPS) e7.2 e9.0 e6.4 e6.0 e6.2 e5.6 e5.0 e4.6 e4.7 e4.6 e4.5 e4.4 e4.4 e4.4 e4.2 e4.1 e4.0 e4.0 e3.6 e3.6 e3.0 e2.6 e2.6 e2.5 e2.4 e2.9 e3.0 e2.6 e2.4 e2.2 e2.0 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) DECEMBER 16 .41 16 16 17 17 17 17 17 17 16 16 16 16 16 16 15 15 15 15 15 15 14 14 14 14 14 14 13 13 13 13 .39 .36 .29 .26 .27 .24 .22 .21 .21 .20 .19 .19 .19 .16 .17 .17 .16 .16 .15 .13 .11 .10 .10 .09 .10 .11 .10 .09 .06 .07 154.1 6.94 129.3 5.72 e Estimated RIO GRANDE DB LOIZA BASIN 231 50055170 RIO CAGUITAS NEAR CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL MEAN DISCHARGE (CPS) el. 9 el. 8 el. 7 el. 6 el. 5 el. 4 el. 4 el. 3 el. 2 e2.5 e3.0 e2.5 e2.2 el. 8 el. 5 el. 4 el. 3 el. 2 el.l el.O el. 8 el. 3 el.O • .90 e.85 •4.7 e5.2 e3.4 e2.5 e2.0 el. 8 58.75 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) JANUARY 13 .07 13 13 13 12 12 12 12 12 12 12 12 11 11 11 11 11 11 11 11 10 10 10 10 10 14 8 9 11 12 19 .06 .06 .06 .05 .05 .05 .04 .04 .06 .09 .08 .07 .06 .05 .04 .04 .04 .03 .03 .04 .04 .03 .03 .02 .09 .11 .10 .08 .07 .10 1.78 MEAN DISCHARGE (CPS) el. 6 el. 5 •1.3 el. 3 el. 2 •1.1 •1.0 .98 .97 .95 .93 .91 .88 .88 .86 .84 .82 .84 .82 .80 eB.O e7.0 •6.5 e3.5 e2.5 elO •6.0 e4.5 ___ ___ —— MEAN CONCEN- TRATION (MG/L) FEBRUARY 20 21 20 15 19 19 18 17 18 12 9 16 26 22 11 12 14 14 12 11 167 155 92 53 22 26 32 21 —— 68.48 --- SEDIMENT DISCHARGE (TONS /DAY) e.09 e.09 e.07 e.05 e.06 e.06 • .05 e.05 • .05 e.03 e.02 e.04 e.06 e.05 e.02 e.03 e.03 e.03 • .03 e.02 el. 7 •3.1 el. 7 e.71 e.18 e.40 • .68 e.29 ___ —— 9.69 MEAN DISCHARGE (CPS) e3.2 •3.9 •2.5 •2.2 el. 9 •1.8 el. 6 el. 5 el. 4 el. 4 el. 3 el. 5 e2.5 e6.0 •3.5 e2.5 e2.0 el. 5 el. 3 •1.4 el. 2 el.O .82 .79 .79 .78 .81 .78 .79 .77 .76 54.19 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) MARCH 19 .20 13 9 7 9 12 16 19 11 15 19 12 7 16 14 12 11 10 9 8 7 6 10 13 8 9 18 11 6 5 5 .12 .08 .05 .05 .06 .07 .08 .04 .06 .07 .04 .04 .18 .18 .10 .07 .05 .03 .03 .02 .02 .02 .03 .02 .02 .04 .02 .01 .01 .01 —— 1.82 e Estimated 232 RIO GRANDE DE LOIZA BASIN 50055170 RIO CAGCTITAS NEAR CAGtTAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 .77 .79 .77 .74 .79 .77 .79 .81 .84 .84 .90 3.1 1.8 1.5 2.3 2.8 1.7 el. 5 el. 3 el. 2 el.l el.O e.97 e.95 e.90 .84 .82 .78 .74 .72 APRIL 6 6 7 8 9 10 12 18 18 26 18 30 23 25 17 41 43 39 36 33 30 28 26 24 22 20 20 20 20 20 ___ MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MAY .01 .01 .02 .02 .02 .02 .03 .04 .04 .06 .04 .31 .11 .10 .11 .30 .20 e.18 e.14 e.ll e.09 e.08 .07 .06 .05 .05 .05 .04 .04 .04 e.74 e.76 e.82 a. 90 el. 2 el. 5 e7.0 e50 elO e4.5 e2.5 e2.0 el. 8 e2.7 e4.0 e3.2 e2.4 e2.4 e2.5 e2.5 e2.3 e2.2 e2.0 el. 9 el. 9 el. 9 e2.0 e2.0 e2.9 e4.4 e2.8 20 20 20 20 20 20 20 186 57 28 25 22 19 14 14 14 13 11 9 8 8 18 17 15 14 14 14 14 15 18 19 e.04 e.04 e.04 a. 05 .06 e.07 e.19 e81 e3.6 e.53 e.23 e.13 e.10 e.09 e.12 e.13 e.10 e.07 e.06 e.05 e.05 e.ll .10 .08 .07 .07 .07 .08 .10 .18 .18 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) JUNE e2.2 e4.1 e6.0 e2.2 e2.6 e2.3 e2.4 e2.4 e3.1 e2.8 e2.5 e2.5 e2.6 e3.3 e3.9 e3.6 e3.1 e2.1 e2.0 e2.8 e3.7 e2.4 e2.2 e2.1 e2.1 e3.0 e2.8 e2.4 e2.0 el. 9 16 118 99 14 10 10 19 25 11 16 25 28 30 29 29 42 42 41 31 31 23 16 15 13 17 27 19 10 12 10 ___ e.ll el.O el. 3 e.16 e.07 e.06 e.12 e.16 e. 08 e.13 e.18 e.19 e.20 e.23 e.28 e.42 e.37 e.28 e.17 e.20 e.20 e.13 e.09 e.08 e.10 e.18 e.15 e.07 e.07 e.05 TOTAL 34.83 2.44 129.72 87.79 83.1 6.83 e Estimated RIO GRANDB DE LOIZA BASIN 50055170 RIO CAGUITAS NEAR CAGUAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) 233 i 2 3 4 5 6 7 e 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR e Estimated JULY «2.1 «2.0 el. 9 el. 9 el. 9 el. 9 e2.0 el. 9 el. 6 el. 8 el. 6 el. 9 el. 8 el. 9 el. 8 el. 8 el. 9 el. 8 el. 9 el. 9 «3.0 e6.0 e3.0 e2.0 e2.5 e3.5 >10 e5.8 e3.7 e2.5 e2.3 82.0 16.57 16 10 7 19 12 14 14 13 12 12 10 4 4 5 9 15 13 11 26 12 7 353 52 16 35 32 33 34 35 36 37 —— e.09 e.06 e.03 e.10 e.06 e.07 e.07 e.07 e.06 e.06 e.05 e.02 e.02 e.02 e.04 e.08 e.06 e.06 e.13 e.06 e.05 e4.8 e.72 e.10 e.21 e.26 e.55 e.70 e.44 e.29 e.24 9.57 9457.54 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MEAN DISCHARGE (CPS) AUGUST e2 e2 elO e2 e2 e2 e2 e2 e2 e2 e2 e2 e2 e2 e2 e3 e3 e9 e25 elO e7 e6 e6 e6 e5 e3 e3 e3 e2 e2 e2 143 .2 .3 .5 .2 .2 .3 .2 .2 .3 .3 .4 .5 .7 .9 .5 .7 .0 .0 .0 .4 .0 .2 .8 .5 .0 .8 .7 .8 .6 38 39 40 41 42 38 22 28 26 24 23 21 20 19 18 17 16 27 215 292 305 298 236 186 147 116 92 72 57 45 36 .23 .24 .57 .59 .27 .23 .13 .17 .16 .15 .14 .14 .13 .13 .14 .15 .16 .50 e9.7 e!3 e6.9 e5.2 e3.9 e3.1 e2.2 el. 4 e.90 e.64 e.45 e.34 e.26 52.22 e2. e2. e2. e2. elOO 508 250 182 e!25 e70 e30 e20 e!5 elO e8. 275 74 e35 e!8 e!3 elO e8. e7. e6. e6. e6. e35 e!4 e8. e6.— 1850. MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) SEPTEMBER 7 6 6 5 0 0 0 6 5 4 0 0 - 9 28 22 18 14 643 2980 633 623 17 10 16 19 21 23 63 997 89 36 23 18 14 8 8 13 15 18 24 35 21 19 e. e. e. e. e238 6840 738 366 e6. e2. e2. el. e. e. e8. 975 18 e3. el. e. e. e. e. e. e. e. el. e2. e. e. - 9209. 11 16 12 10 0 2 0 3 98 77 6 8 3 75 43 19 16 24 27 31 2 2 60 39— 28 234 RIO GRANDE DE LOIZA BASIN 50055170 RIO CAGUITAS NEAR CAGUAS, PR--Continued HATER QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DATE OCT 1994 13. .. 22. .. 24. .. JAN 1995 28. .. FEB 21... APR 16. .. JUN 02. .. 21. .. JUIi 21... 22. .. AUO 19. .. SEP 05. .. 19. . . TIME 1705 2239 0915 0900 1045 0930 0950 0900 0605 1855 0930 0930 1635 STREAM- FLOW, INSTAN- TANEOUS (CFS) 3.4 e206 elS e3.4 eS e2.8 e4.1 e3.7 e3 e6 e25 elOO elS SEDI- MENT, SUS- PENDED (MO/L) 133 461 203 8 223 47 229 91 1380 1430 294 174 296 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 1.2 e256 e.9 eO.07 e4.8 eO.4 e2.5 eO.9 ell. 2 e23.2 e!9.8 e47 el4.4 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 89 78 85 72 99 97 95 97 99.6 99.8 95 94 94 e Estimated 235 RIO CRANDE DE LOIZA BASIN 50055225 RIO CAGUITAS AT VILLA BLANCA AT CAGUAS, PR LOCATION.--Lat 180 14'55 M , long 66°01'40", Hydrologic Unit 21010005, on left bank, at C. 4 street Villa Blanca housing area at Caguas, 1.8 mi (2.9 km) upstream from Rio Crande de Loiza, and 0.95 mi (1.53 km) northeast from Caguas Plaza. DRAINAGE AREA.--11.71 mi 1 (30.33 km'). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 164 ft (50 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. Low-flow affected by pluvial discharge about 50 ft upstream from station. DISCHARGE, CUBIC FEET PER SECOND, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY NOV FEB APR HAY JUN JUL AUG SEP 1 eB.O e7.2 2 e7.0 e7.0 3 e6.4 e6.6 4 e6.2 e6.4 5 eS.6 e6.4 6 e7.0 e9.0 7 e8.4 e7.9 6 e9.6 e7.4 9 e7.6 e7.4 10 e6.4 ell 11 e7.6 eS.O 12 e6.e e7.0 13 e6.2 e6.e 14 e6.0 e6.6 15 eS.6 e6.2 16 e5.6 e6.2 17 e7.6 e6.2 Id eSO e6.6 19 e72 e6.2 20 e60 e6.2 21 e!5 e7.0 22 e73 e6.6 23 eieO e6.2 24 e!40 e6.0 25 e9.3 e7.4 26 e8.6 e7.4 27 e8.2 e6.6 28 e8.2 e6.4 29 e7.2 elOO 30 e8.0 e70 31 e7.6 TOTAL 765.1 366.3 MEAN 24.7 12.2 MAX 180 100 HIN 5.6 6.0 MED 7.6 6.8 AC-FT 1520 727 CFSM 2.11 1.04 IN. 2.43 1.16 e25 e59 e9.6 e8.8 e9.8 e8.6 e7.6 e7.4 e7.2 e6.8 e6.6 e6.6 e6.6 e6.6 e6.2 e6.2 e6.0 e6.0 e6.0 e5.6 e5.6 e5.6 e5.6 e5.6 e5.6 e5.3 e6.0 e6.8 e5.6 e5.6 e5.6 275.1 8.87 59 5.3 6.2 546 .76 .87 STATISTICS OF MONTHLY MEAN DATA MEAN 24.5 36.2 MAX 27.6 56.8 (WY) 1993 1993 MIN 20.0 12.2 (WY) 1992 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 24.1 58.4 1993 8.87 1995 FOR e5.6 e5.6 e6.2 e6.2 e5.6 e5.6 e6.6 e6.2 e6.8 e41 e20 e47 e6.8 e6.4 e6.2 e6.0 e6.0 e6.0 e8.0 e7.2 e6.0 e6.0 e6.0 e5.6 e5.6 e90 e25 e60 e7.6 e6.8 e6.2 439.8 14.2 90 5.6 6.2 872 1.21 1.40 e5.8 e5.6 e5.6 e5. e5. e5. e5. e5. eS.O eS.O eS.O e4.7 eS.O eS.O e5.6 e6.0 e5.6 e5.4 e6.0 e5.4 e86 e32 e25 e35 e!30 e82 e30 ellO ___ ___ --- 637.7 22.8 130 4.7 5.6 1260 1.94 2.03 FOR WATER YEARS 1991 39.9 120 1992 14.2 1995 18.0 23.8 1991 10.8 1992 e20 elO e9.2 ell e9.6 e8.4 e8.2 e9.0 e8.0 e8.0 e8.8 e9.6 e52 e36 e9.4 e8.2 e7.8 e7.6 e7.2 e7.0 e6.6 e6.4 e6.4 e6.0 e6.0 e5.6 e5.6 e5.6 e5.2 e5.2 e5.2 318.8 10.3 52 5.2 8.0 632 .88 1.01 - 1995 10.7 15.3 1991 7.54 1994 1994 CALENDAR YEAR 3323 9 180 1 1 6590 10 14 5 2 .3 .10 Oct 23 . 3 Jun 8 . 4 Jun 8 .78 .56 .8 .4 e5.2 e5.2 e5.2 e4.8 e4.8 e4.6 eS.O e5.8 e5.4 e5.2 e5.6 e9.2 e6.0 e5.6 e8.4 e8.4 e6.4 eS.8 e6.8 e5.8 e5.6 eS.O eS.O e5.4 e5.4 e5.6 e5.8 e6.4 e6.8 e6.4 --- 179.6 5.99 9.2 4.6 5.6 356 .51 .57 e6.0 e6.6 e5.6 e6.0 e!5 e39 e40 e270 e21 e!6 e!3 e!3 e!4 e35 e76 e!8 e!4 e!4 e!5 e20 e!5 e!4 e!3 e!2 e!2 e!3 e!4 e!4 e40 e96 e22 922.2 29.7 270 5.6 14 1830 2.54 2.93 elB e46 e!40 e21 e25 e22 e25 e25 e39 e33 e30 e30 e32 e41 e60 e45 e38 e29 e28 e33 e41 e26 e23 e21 e21 e34 e31 e26 e20 e20 --- 1023 34.1 140 18 29 2030 2.91 3.25 e!9 e!9 e!9 elB elB e!8 e22 e!8 e!6 e!4 e!8 e!5 e!7 e!9 e!6 e!6 e!6 e!8 e!8 e!6 e!6 e!20 e!9 e!6 e!9 e21 e210 e64 e41 e23 e20 919 29.6 210 14 18 1820 2.53 2.92 e!9 e!9 e!70 e23 el 9 e21 e!9 e!9 e!9 e21 e21 e!9 e20 e23 e23 e27 e25 e485 e258 e80 e50 e64 e54 e56 e62 e44 e36 e29 e25 e24 e23 1797 58.0 485 19 24 3560 4.95 5.71 e23 e22 e21 e21 ellO e!450 e205 e68 e36 e26 e23 e21 e20 e!9 e!70 e468 ellO e40 e33 e28 e21 e!7 e21 e!6 e!5 e!5 e56 e23 e23 e!6 3137 105 1450 15 23 6220 8.93 9.97 , BY WATER YEAR (WY) 14.7 39.8 1993 5.49 1994 FOR 1995 10780 29 1450 4 5 7920 17 21380 2 34 56 9 5 28.1 59.8 1993 3.35 1994 WATER YEAR .6 .5 Sep 6 .6 Apr 6 .0 Mar 31 Sep 6 .26 Sep 6 .52 .25 .6 .6 19.0 34.1 1995 2.86 1994 29.1 74.6 1993 4.13 1994 WATER 27 40 11 1930 1 1 13400 19 20230 2 32 39 13 5 29.2 58.0 1995 3.82 1994 YEARS 1991 .9 .1 .9 Jan .3 Jun .4 Jun Jan .91 Jan .39 .41 .2 42.0 105 1995 8.82 1994 - 1995 1993 1994 5 1992 8 1994 8 1994 5 1992 5 1992 e Estimated 236 RIO GRANDE DE LOIZA BASIN 50055225 RIO CAG0ITAS AT VILLA BLANCA AT CAGDAS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1991 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: December 1990 to September 1995. INSTRUMENTATION.-- Automatic sediment sampler since 1991. REMARKS.-- Sediment samples collected by local observer on a weekly basis and during high flow events. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,430 mg/L Jan. 05, 1992; Minimum daily mean, 5 mg/L Several days. SEDIMENT LOADS: Maximum daily mean, 8,820 tons (8,000 tonnes) Jan. 05, 1992; Minimum daily mean, eO.03 ton (eO.02 tonne) June 15, 1994. EXTREMES FOR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,420 mg/L September 16, 1995; Minimum daily mean, 6 mg/L Several days. SEDIMENT LOADS: Maximum daily mean, 4,830 tons (4,360 tonnes) September 06, 1995; Minimum daily mean, eO.09 ton (eO.08 tonne) May 04, 1995. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 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 e8.0 10 e.21 e7.2 13 e.27 e25 86 elO 2 e7.0 10 e.19 e7.0 11 e.22 e59 139 e!5 3 e6.4 10 e.18 e6.8 9 e.18 e9.6 160 e!2 4 e6.2 13 e.22 e6.4 9 e.16 e8.8 171 e4.2 5 e5.8 18 e.30 e6.4 10 e.17 e9.8 180 e4.5 6 e7.0 24 e.42 e9.0 10 e.21 e8.6 146 e3.6 7 e8.4 21 e.45 e7.9 11 e.24 e7.6 107 e2.3 8 e9.6 16 e.39 e7.4 11 e.24 e7.4 80 el.6 9 e7.6 13 e.30 e7.4 12 e.24 e7.2 87 el.7 10 e6.4 16 e.29 ell 13 e.32 e6.8 109 e2.1 11 e7.6 21 e.40 e8.0 14 e.36 e6.6 136 e2.5 12 e6.8 27 e.53 e7.0 15 e.30 e6.6 162 e2.9 13 e6.2 27 e.47 e6.8 17 e.32 e6.6 192 e3.4 14 e6.0 24 e.40 e6.6 19 e.35 e6.6 224 e4.0 15 e5.8 22 e.35 e6.2 21 e.37 e6.2 206 e3.6 16 e5.6 19 e.30 e6.2 21 e.35 e6.2 173 e2.9 17 e7.6 17 e.29 e6.2 20 e.33 e6.0 148 e2.4 18 e50 29 e2.4 e6.6 18 e.32 e6.0 144 e2.3 19 e72 147 e25 e6.2 17 e.30 e6.0 144 e2.3 20 e60 126 e23 e6.2 16 e.27 e5.6 143 e2.2 21 e!5 26 e2.5 e7.0 15 e.27 e5.6 127 el.9 22 e73 151 e!9 e6.6 15 e.27 e5.6 108 el. 6 23 e!80 392 e!27 e6.2 14 e.24 e5.6 339 e5.1 24 e!40 305 e!33 e6.0 13 e.21 e5.6 555 e8.4 25 e9.3 102 e!6 e7.4 12 e.22 e5.6 549 e8.3 26 e8.6 30 e.72 e7.4 12 e.23 e5.3 539 e7.9 27 e8.2 12 e.28 e6.8 11 e.21 e6.0 476 e7.3 28 e8.2 12 e.27 e6.4 10 e.18 e6.8 406 e7.0 29 e7.2 15 e.31 elOO 85 e!2 e5.6 342 e5.7 30 e8.0 18 e.37 e70 156 e36 e5.6 242 e3.7 31 e7.6 16 e.34 —— —— —— e5.6 161 «2.4 TOTAL 765.1 --- 355.88 366.3 —— 55.35 275.1 --- 144.8 e Estimated RIO GRANDE DE 1XDIZA BASIN 237 50055225 RIO CAGUITAS AT VILLA BLANCA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 e5.6 e5.6 e6.2 e6.2 e5.6 e5.6 e6.6 e6.2 e6.8 e41 e20 e47 e6.8 e6.4 e6.2 eS.O eS.O eS.O e8.0 e7.2 eS.O eS.O eS.O e5.6 e5.6 e90 e25 e60 e7.6 e6.8 e6.2 107 71 63 60 57 48 39 31 32 109 257 135 79 54 57 66 70 49 32 21 21 23 26 31 38 108 137 108 85 67 51 el. 6 el.l el.O el.O e.91 e.73 e.63 e.54 e.56 e6.6 e20 ell e4.7 e.97 e.98 el.l el.l e.79 e.60 e.44 e.37 e.37 e.42 e.49 e.58 e!2 e!9 e!2 eS.O el. 3 e.89 e5 e5 e5 e5 e5 e5 e5 e5 e5 e5 e5 e4 e5 e5 e5 e6 e5 e5 e6 e5 e86 e32 e25 e35 e!30 e82 e30 ellO - _ - MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) FEBRUARY .8 .6 .6 . . .0 .0 .0 .7 .0 .0 .6 .0 .6 .4 .0 .4 ——— 38 29 30 127 172 181 191 202 212 223 219 212 204 197 191 184 174 163 154 146 139 131 117 104 92 85 72 112 e.62 e.45 e.45 el. 9 e2.5 62.6 e2.8 62.9 63.0 63.0 63.0 62.8 e2.7 e2.7 e2.7 62.9 e2.7 62.4 62.4 62.2 ell e!9 69.0 68.3 e!8 e24 elO e22 e20 elO 69. ell 69. e8. e8. e9. e8. e8. e8. 69. e52 e36 69. e8. e7. e7. e7. e7. e6. 66. e6. e6. e6. e5. e5. e5. e5. e5. e5. MARCH 2 6 4 2 0 0 0 8 6 4 2 8 6 2 0 6 4 4 0 0 6 6 6 2 2 2 71 44 33 25 19 15 13 11 11 19 40 80 121 94 61 32 16 8 8 10 13 16 19 23 21 18 15 14 19 30 45 e!2 el. 7 e.86 e.69 e.54 e.36 e.29 e.26 e.25 6.41 e.90 e2.0 e8.3 ell e3.4 e.77 e.34 e.17 e.17 e.20 e.23 e.27 e.33 e.38 e.34 e.28 e.23 6.21 e.28 e.42 e.63 TOTAL 439.8 109.77 637.7 168.02 318.8 48.21 « Estimated 238 RIO GRANDS DE LOIZA BASIN 50055225 RIO CAGUITAS AT VILLA BLANCA AT CAGUAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 eS. e5. e5. e4. e4. e4. e8. eS. e5. e5. eS. e9. e6. e5. e8. e8. e6. e5. e6. e5. eS. e5. e5. eS. e5. e5. eS. e6. e6. e6. -- 2 2 2 8 8 6 0 8 4 2 6 2 0 6 4 4 4 8 8 8 6 0 0 4 4 6 8 4 8 4 - APRIL 43 .60 37 32 27 24 20 17 15 13 11 10 8 8 9 9 9 10 10 10 10 10 9 9 8 7 7 6 6 6 6 .52 .45 .37 .31 .26 .29 .28 .19 .16 .14 .16 .17 .13 .17 .21 .19 .16 .17 .17 .15 .13 .12 .11 .11 .10 .09 .10 .11 .11 ___ ___ MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MAY e6.0 e6.6 e5.6 e6.0 elS e39 e40 e270 e21 e!6 e!3 e!3 e!4 e35 e76 e!8 e!4 e!4 elS e20 elS e!4 e!3 e!2 e!2 e!3 e!4 e!4 e40 e96 e22 6 6 6 6 38 93 138 444 429 67 118 245 66 94 150 62 44 43 46 54 46 43 35 11 411 45 11 9 71 91 64 e. e. e. e. el. e6. e!5 e!46 e98 e3. e4. eS. e2. e6. e21 e7. el. el. el. e2. e2. el. el. e. e!3 el. e. e. e5. e!6 e9. 10 10 10 09 1 6 4 5 6 4 2 3 9 6 8 5 2 7 3 38 5 41 34 4 0 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) JUNE el 8 e46 e!40 e21 e25 e22 e25 e25 e39 e33 e30 e30 e32 e41 e60 e45 e38 e29 e28 e33 e41 e26 e23 e21 e21 e34 e31 e26 e20 e20 ___ 45 16 181 73 25 10 12 14 13 12 10 10 9 11 108 99 21 15 17 21 77 51 32 25 21 18 15 12 10 9 ___ e2.5 el. 3 e44 elS el.S e.61 e.75 e.96 el.l el.l e.87 e.78 e.78 el.l e!5 e!4 e2.4 el. 4 el. 3 el. 7 e7.7 e4.6 e2.1 el.S el. 2 el. 3 el. 3 e.96 e.64 e.49 ___ TOTAL 179.6 6.23 922.2 379.52 1023 129.94 e Estimated 239 RIO GRANDE DE LOIZA BASIN 50055225 RIO CAGDITAS AT VILLA BLANCA AT CAGUAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAY 1 2 3 4 5 6 7 a 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) el 9 e!9 e!9 el8 el8 el8 e22 el8 e!6 e!4 el8 e!5 e!7 e!9 e!6 e!6 e!6 el8 el8 e!6 e!6 e!20 e!9 e!6 e!9 e21 e210 e64 e41 e23 e20 JOLY 8 7 8 8 7 7 7 8 8 10 14 18 18 16 14 13 13 12 14 18 29 194 111 45 36 32 111 114 80 40 21 TOTAL 919 — - YEAR e 10780.6 Estimated MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) A0GUST e. e. e. e. e. e. e. e. e. e. e. e. e. e. e. e. e. e. e. e. el. e29 e!9 e2. el. el. e!9 e35 ell e3. el. 135. 10480. 42 37 40 38 36 35 39 41 37 42 59 78 76 77 67 58 55 56 69 80 3 1 7 7 5 2 12 28 e!9 e!9 e!70 e23 e!9 e21 e!9 e!9 e!9 e21 e21 e!9 e20 e23 e23 e27 e25 e485 e258 e80 e50 e64 e54 e56 e62 e44 e36 e29 e25 e24 e23 1797 16 13 188 82 51 41 33 26 19 13 10 9 8 8 8 7 7 587 590 143 131 128 32 114 120 15 11 14 19 18 17 —— e. e. e4l el9 e2. e2. el. el. e. e. e. e. e. e. e. e. e. e346 e602 e63 e22 e!9 e5. e!7 e!9 e2. el. el. el. el. el. 1176. 82 65 9 2 8 4 98 73 55 47 44 47 48 50 50 1 3 1 2 4 2 1 29 MEAN DISCHARGE (CPS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) SEPTEMBER e23 e22 e21 e21 ellO el450 e205 e68 e36 e26 e23 e21 e20 e!9 e!70 e468 ellO e40 e33 e28 e21 e!7 e21 e!6 e!5 el5 e56 e23 e23 e!6 3137 15 14 13 12 132 958 190 571 76 20 12 11 11 11 222 1420 493 93 39 27 22 19 24 32 43 43 389 84 51 43 --- —— e.95 e.86 e.77 e.70 e22 e4930 e!76 e!39 ell el. 7 e.77 e.67 e.60 e.55 e91 e2250 e!64 e!2 e3.9 e2.2 el. 5 e.98 el. 2 el. 6 el. 8 el. 8 e39 e9.1 e3.2 e2.3 ___ 7771.15 240 RIO GRANDE DE LOIZA BASIN 50055225 RIO CAGOITAS AT VILLA BLANCA AT CAGOAS, PR—Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DATE FEE 1995 25. .. MAY oe... SEP 06. . . 06. .. 06. .. 16. .. 16. .. 27. .. DATE FEB 1995 25. .. MAY oe... SEP 06. . . 06. . . 06. .. 16. .. 16. .. 27. .. TIME 1627 1730 0430 0545 1230 0327 0417 1400 SED. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 62 73 62 53 80 67 62 83 DIS- CHARGE, INST. CUBIC FEET PER SECOND e3899 e!355 1268 5530 535 824 620 e56 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 76 76 77 65 87 78 68 89 SEDI- MENT, SUS- PENDED (MG/L) 4850 1730 4980 9490 7670 4480 5800 4490 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 85 88 87 78 93 89 84 95 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) eSlOOO e6330 17000 142000 11100 9970 9700 e680 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 91 94 94 93 97 96 93 98 SED. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 37 53 27 28 40 38 40 54 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 96 98 97 98 99 99 97 99 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 40 57 35 34 53 42 44 61 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 98.9 99.4 99 99.6 99.7 99.8 98 99.8 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 49 66 46 42 66 54 55 73 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 99.5 99.7 99.4 99.9 99.9 99.9 99 99.9 e Estimated RIO GRANDE DE LOIZA BASIN 241 50055225 RIO CAGUITAS AT VILLA BLANCA AT CAGUAS, PR—Continued HATER QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 22.. . DEC 05.. . JAN 1995 26.. . PEB 07.. . MAY 05.. . AUG 08. .. SEP 06. . . 06.. . 08.. . 15.. . 16.. . 16.. . 16.. . 16.. . 17.. . SILT AND TIME 2030 1510 1405 1526 1330 0001 0400 1225 1350 2247 0517 1047 1415 1505 1518 CLAY PERCENT OF SUSPENDED SEDIMENT SED. SEDI- SUSP. STREAM- PLOW, INSTAN- TANEOUS (CPS) e73 e9.8 e90 e5.4 e!5 e!9 493 881 55 183 770 484 373 318 132 SEDI- MENT, SUS- PENDED (MG/L) 303 2180 171 908 3280 3030 5500 662 4430 6270 2920 1030 720 600 608 MENT, DIS- CHARGE, SUS- PENDED (T/DAY) e60 e58 e41 e!3 e!33 e!55 7320 1570 658 3100 6070 1350 725 515 217 SIEVE DIAM. PERCENT PINER THAN .062 MM 83 98 93 91 100 91 94 96 74 62 88 92 92 94 96 e Estimated 242 RIO GRANGE DE LOIZA BASIN 50055250 RIO CAQUITAS AT HIGHWAY 30 AT CAQUAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°15'll n , long 66°01'26", at Highway 30 bridge, and 0.8 mi (1.3 km) east of Caguae plaza. DRAINAGE AREA.--14.1 mi' (36.5 km'). PERIOD OP RECORD.—Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 11. .. DEC 12. .. FEB 1995 08. .. APR 07. .. JUN 08. .. AUG 14. . . DATE OCT 1994 11. .. DEC 12. .. FEB 1995 08... APR 07. .. JUN 08. .. AUG 14. .. TIME 0850 0850 0930 0720 0900 1040 HARD- NESS TOTAL (MG/L AS CACO3) 170 -- -- 160 -- 160 SILICA, DATE OCT 1994 11. .. DEC 12. .. FEB 1995 08. .. APR 07. .. JUN 08. .. AUG 14. .. K = non- ideal DIS- SOLVED (MG/L AS SIO2) 38 -- -- 33 -- 33 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 14 20 16 13 17 14 CALCIUM DIS- SOLVED (MG/L AS CA) 45 -- -_ 43 __ 42 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 432 -- -- 368 -- 388 SPE- CIFIC CON- DUCT- ANCE (US/CM) 664 631 620 564 644 710 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 14 __ __ 12 __ 13 SOLIDS, DIS- SOLVED (TONS PER DAY) 16.7 — -- 12.5 — 14.6 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.1 7.1 7.2 7.1 7.3 7.5 SODIUM, DIS- SOLVED (MG/L AS HA) 71 __ __ 53 __ 57 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED •(MG/L) 23 17 7 22 16 10 TEMPER- ATURE WATER (DEG C) 29.5 24.0 25.0 28.0 29.0 30.0 SODIUM AD- SORP- TION RATIO 2 __ __ 2 __ 2 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 18 15 24 14 18 15 TUR- BID- ITY (NTU) 3.3 23 6.5 4.1 3.6 2.5 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 11 __ __ 7.3 __ 9.2 PHOS- PHORUS TOTAL (MG/L AS P) 2.80 2.00 1.50 1.70 2.10 2.40 OXYGEN, DIS- SOLVED (MG/L) 1.0 3.8 1.0 4.0 0.2 2.4 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 200 180 200 200 200 210 ARSENIC TOTAL (UG/L AS AS) 3 -- -- 2 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 13 46 12 49 3 32 SULFIDE TOTAL (MG/L AS S) <0.5 __ __ <0.5 __ ~~ BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 85 73 110 110 81 72 SULFATE DIS- SOLVED (MG/L AS 804) 53 __ __ 40 __ 39 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 160 -- — 110 -- — COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 52000 470000 270000 K760000 32000 24000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 80 -- __ 60 __ 69 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 270 550000 5200 460000 8300 K5000 FLUO- RIDB, DIS- SOLVED (MG/L AS F) 0.20 -- __ 0.20 _- 0.20 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 37 -- -- 7 -- — 243 RIO GRANDE DE LOIZA BASIN 50055250 RIO CAGUITAS AT HIGHWAY 30 AT CAGUAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 11. .. DEC 12... FEB 1995 08. .. APR 07... JUN 08... AUG 14. .. MANGA- MBTHY- COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LBNE TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- NIOM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SOB- (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CTJ) AS FE) AS PB) AS MN) AS HG) AS SB) AS AG) AS ZN) AS CN) (UG/L) (MG/L) 20 410 2 300 <0.10 <1 2 30 <0.010 <1 1.6 __ __ 20 800 3 720 <0.20 <1 2 50 <0.010 12 3.9 __ -- 244 RIO GRANDE DE LOIZA BASIN 50055390 RIO BAIROA AT BAIROA, PR LOCATION.—Lat 18°15'32", long 66°02'24", Hydrologic Unit 21010005, on left bank, in the Bairoa Housing Area, 1.6 mi (2.6 km) northwest of Plaza de Caguas, 4.1 mi (6.6 km) east of Plaza de Aguas Buenas, and 0.9 mi (1.4 km) northwest of Escuela Fepita Garriga. DRAINAGE AREA.--5.08 mi 2 (13.15 km2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1990 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 131 ft (40 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. Mean daily discharge affected by domestic discharge from nearby station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY DEC MAY SEP 1 5.9 4.9 2 3.4 4.9 3 3.2 4.5 4 3.2 4.4 5 3.3 4.4 6 3.0 4.8 7 7.9 4.0 8 13 4.0 9 4.3 5.1 10 3.3 4.6 11 3.6 4.3 12 3.3 3.9 13 3.6 3.8 14 3.3 3.5 15 3.4 3.7 16 3.1 3.5 17 3.9 3.2 18 8.6 3.2 19 8.0 3.3 20 12 3.3 21 4.8 5.0 22 26 3.7 23 35 3.6 24 14 3.6 25 6.0 11 26 4.8 4.5 27 5.0 4.5 28 6.2 4.1 29 5.3 30 30 5.0 20 31 6.2 --- TOTAL 221.6 171.3 MEAN 7.15 5.71 MAX 35 30 MIN 3.0 3.2 AC-FT 440 340 CFSM 1.41 1.12 IN. . 1.62 1.25 STATISTICS OF MONTHLY MEAN MEAN 10.1 10.1 MAX 25.3 22.2 (WY) 1991 1993 MIN 4.30 5.71 (WY) 1992 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 7.4 17 11 23 9.7 5.9 5.3 4.9 4.6 4.5 4.4 4.5 4.6 4.7 4.8 4.3 4.5 4.5 4.2 4.0 4.1 3.9 3.9 4.0 4.0 3.7 4.5 4.4 3.4 3.6 3.5 180.8 5.83 23 3.4 359 1.15 1.32 DATA 9.09 19.7 1993 4.63 1992 FOR 3.5 3.4 3.6 3.9 3.7 3.7 3.7 3.9 4.0 6.0 4.2 10 3.5 3.4 3.3 3.2 3.0 3.0 4.7 4.0 3.0 2.8 2.7 2.7 2.6 14 3.8 6.0 3.0 2.7 2.6 127.6 4.12 14 2.6 253 .81 .93 FOR WATER 7.87 13.6 1992 4.12 1995 2.8 2.8 2.5 2.3 2.3 2.3 2.6 2.5 2.8 3.1 3.2 2.7 2.8 2.6 3.4 3.5 2.8 2.2 2.7 2.5 13 2.4 2.1 2.1 22 5.5 5.8 35 ___ ___ --- 142.3 5.08 35 2.1 282 1.00 1.04 YEARS 1991 5.00 8.60 1991 3.42 1994 7.2 5.4 5.6 6.2 5.3 4.6 4.2 4.5 4.6 4.6 4.2 5.3 10 7.8 4.3 3.8 3.5 3.6 3.5 3.5 3.4 3.2 3.1 2.9 3.0 2.6 2.4 2.6 2.6 2.9 3.0 133.4 4.30 10 2.4 265 .85 .98 - 1995 3.91 5.18 1991 2.87 1994 1994 CALENDAR YEAR 1714. 4. 35 2. 2. 3400 . 12. 6. 3. 2. 5 70 Oct 23 2 Apr 22 3 Apr 20 92 55 3 8 7 3.0 2.9 2.6 2.5 2.5 2.5 3.0 2.3 2.3 2.6 2.7 5.5 3.1 2.7 13 2.9 2.8 2.1 2.3 2.1 2.0 1.8 1.8 1.9 1.9 2.0 2.1 2.3 2.4 2.3 —— 85.9 2.86 13 1.8 170 .56 .63 2.2 2.3 2.0 2.2 3.0 8.1 8.4 23 4.3 3.3 2.8 2.7 2.8 2.7 3.1 3.5 3.4 3.1 2.5 4.2 2.1 2.0 1.9 2.0 1.6 1.9 1.7 1.9 2.0 3.1 2.6 112.4 3.63 23 1.6 223 .71 .82 2.5 6.9 4.5 2.4 2.2 2.1 2.1 2.3 2.2 2.3 2.3 2.4 2.2 2.2 2.4 2.4 2.3 2.4 2.3 2.3 2.8 2.3 2.0 2.0 1.9 4.1 6.4 4.3 1.7 1.5 —— 81.7 2.72 6.9 1.5 162 .54 .60 1.7 1.3 1.6 1.6 1.6 1.6 2.1 1.8 1.7 1.8 3.6 3.3 15 7.0 3.3 2.7 2.6 3.5 3.6 e8.5 5.6 e50 8.1 6.2 3.2 2.1 16 7.9 4.0 3.9 2.6 179.5 5.79 50 1.3 356 1.14 1.31 2.5 2.5 32 5.8 3.6 3.3 3.0 3.1 2.9 2.8 2.8 2.4 2.3 2.0 2.2 4.7 3.2 74 27 4.9 3.4 3.9 5.5 6.7 4.7 3.1 2.9 2.5 2.4 2.4 3.6 228.1 7.36 74 2.0 452 1.45 1.67 2.3 2.2 2.0 1.9 14 232 77 51 34 33 25 19 18 18 38 162 56 22 12 9.0 7.9 5.6 6.5 5.2 4.5 4.5 11 4.4 4.2 3.7 —— 885.9 29.5 232 1.9 1760 5.81 6.49 , BY WATER YEAR (WY) 3.88 7.20 1993 2.61 1992 FOR 1995 2550 6 232 1 1 925 10 5060 1 18 11 3 2 6.25 12.5 1993 2.91 1994 WATER YEAR .5 .99 Sep 6 .3 Jul 2 .6 Jun 30 Sep 6 .96 Sep 6 .38 .68 .5 .1 4.95 8.64 1993 2.72 1995 8.59 16.5 1991 4.35 1994 WATER 7 10 4 337 1 1 1580 12 5330 1 19 11 4 2 6.37 7.64 1992 4.09 1991 YEARS 1991 .35 .3 .52 Dec .3 Jul .6 Jun Jan .32 Jan .45 .67 .3 .6 12.0 29.5 1995 4.50 1991 - 1995 1993 1994 26 1992 2 1995 30 1995 5 1992 5 1992 e Estimated 245 RIO GRANDE DE LOIZA BASIN 50055390 RIO BAIROA AT BAIROA, PR--Continued WATER-QUALITY RECORDS PERIOD OP RECORDS.-- Water years 1991 to current year. PERIOD OP DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1994 to September 1995. INSTRUMENTATION.-- Automatic sediment sampler since 1991. REMARKS:— Sediment samples ware collected by a local observer on a weekly basis and during high flows events EXTREMES POR PERIOD OP DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 4,310 mg/L Dec 26, 1992; Minimum daily mean, 2 mg/L Several days. SEDIMENT LOADS: Maximum daily mean, 3,910 tons (3,550 tonnes) Dec 26, 1992; Minimum daily mean, 0.02 ton (0.01 tonne) Several days. EXTREME POR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,080 mg/L September 16, 1995; Minimum daily mean, 3 mg/L Several days. SEDIMENT LOADS: Maximum daily mean, 852 tons (773 tonnes) September 06, 1995; Minimum daily mean, 0.02 ton (0.02 tonne) Several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) OCTOBER 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL 5.9 3.4 3.2 3.2 3.3 3.0 7.9 13 4.3 3.3 3.6 3.3 3.6 3.3 3.4 3.1 3.9 8.6 8.0 12 4.8 26 35 14 6.0 4.8 5.0 6.2 5.3 5.0 6.2 221.6 39 20 24 27 32 30 199 533 49 26 18 17 20 23 24 22 31 236 214 395 33 312 949 591 78 19 11 33 12 9 93 ___ .78 .19 .21 .23 .28 .24 9.8 59 .61 .23 .18 .15 .20 .20 .22 .18 .36 9.8 9.9 20 .43 78 100 25 1.3 .25 .15 1.2 .17 .12 2.8 322.18 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) NOVEMBER MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) DECEMBER 4.9 4.9 4.5 4.4 4.4 4.8 4.0 4.0 5.1 4.6 4.3 3.9 3.8 3.5 3.7 3.5 3.2 3.2 3.3 3.3 5.0 3.7 3.6 3.6 11 4.5 4.5 4.1 30 20 62 63 138 223 307 475 603 479 457 633 469 342 191 97 49 26 23 26 28 24 71 37 30 24 258 38 31 28 631 507 .84 1.0 1.7 2.7 3.6 6.5 6.5 5.1 7.2 7.7 5.4 3.6 2.0 .92 .50 .24 .20 .22 .25 .21 2.2 .37 .29 .23 18 .47 .37 .31 108 48 7. 17 11 23 9. 5. 5. 4. 4. 4. 4. 4. 4. 4. 4. 4. 4. 4. 4. 4. 4. 3. 3. 4. 4. 3. 4. 4. 3. 3. 3. 4 7 9 3 9 6 5 4 5 6 7 8 3 5 5 2 0 1 9 9 0 0 7 5 4 4 6 5 373 551 335 608 401 88 25 21 26 31 29 24 21 18 17 18 18 20 22 23 24 21 17 14 13 12 49 43 17 11 8 8.6 39 14 53 12 1.4 .36 .28 .32 .38 .34 .30 .26 .22 .22 .21 .22 .24 .25 .25 .26 .22 .18 .15 .14 .12 1.2 .68 .15 .10 .07 171.3 234.62 180.8 135.12 246 RIO GRANDE DE LOIZA BASIN 50055390 RIO BAIROA AT BAIROA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 3.5 3.4 3.6 3.9 3.7 3.7 3.7 3.9 4.0 6.0 4.2 10 3.5 3.4 3.3 3.2 3.0 3.0 4.7 4.0 3.0 2.8 2.7 2.7 2.6 14 3.8 6.0 3.0 2.7 2.6 9 12 16 20 17 12 9 9 8 126 32 245 21 16 14 14 14 25 93 260 224 194 167 144 124 320 27 133 18 14 12 .09 .11 .16 .22 .17 .12 .09 .09 .09 3.3 .39 16 .20 .15 .13 .12 .11 .20 3.5 2.8 1.8 1.4 1.2 1.1 .87 20 .28 3.0 .14 .11 .08 FEBRUARY 2.8 2.8 2.5 2.3 2.3 2.3 2.6 2.5 2.8 3.1 3.2 2.7 2.8 2.6 3.4 3.5 2.8 2.2 2.7 2.5 13 2.4 2.1 2.1 22 5.5 5.8 35 10 9 8 7 6 5 11 6 4 5 6 7 7 8 39 21 15 10 10 9 354 20 13 10 270 107 106 721 .08 .07 .05 .04 .04 .03 .08 .04 .03 .04 .05 .05 .05 .06 .89 .20 .11 .06 .07 .06 26 .13 .08 .05 41 2.2 2.4 141 MEAN DISCHARGE (CPS) 7.2 5.4 5.6 6.2 5.3 4.6 4.2 4.5 4.6 4.6 4.2 5.3 10 7.8 4.3 3.8 3.5 3.6 3.5 3.5 3.4 3.2 3.1 2.9 3.0 2.6 2.4 2.6 2.6 2.9 3.0 MEAN CONCEN- TRATION (MG/L) MARCH 133 19 71 392 85 34 23 16 11 8 30 62 341 225 95 49 24 12 10 9 8 7 7 6 6 7 7 8 9 7 5 SEDIMENT DISCHARGE (TONS/DAY) 3.1 .28 2.2 6.7 1.2 .43 .27 .19 .14 .10 .53 .96 14 6.3 1.1 .50 .22 .12 .09 .08 .07 .06 .06 .05 .05 .05 .05 .05 .06 .05 .04 TOTAL 127.6 58.02 142.3 214.96 133.4 39.10 RIO GRANDE DE LOIZA BASIN 50055390 RIO BAIROA AT BAIROA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MAY 247 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 3.0 2.9 2.6 2.5 2.5 2.5 3.0 2.3 2.3 2.6 2.7 5.5 3.1 2.7 13 2.9 2.8 2.1 2.3 2.1 2.0 1.8 1.8 1.9 1.9 2.0 2.1 2.3 2.4 2.3 APRIL 3 4 7 10 14 15 21 6 4 3 3 83 10 10 410 22 12 10 8 8 7 7 6 5 4 4 6 9 12 14 .03 .03 .05 .06 .10 .10 .21 .03 .02 .02 .02 2.0 .09 .07 55 .18 .09 .05 .05 .04 .04 .03 .03 .02 .02 .02 .04 .05 .08 .08 2.2 2.3 2.0 2.2 3.0 8.1 8.4 23 4.3 3.3 2.8 2.7 2.8 2.7 3.1 3.5 3.4 3.1 2.5 4.2 2.1 2.0 1.9 2.0 1.6 1.9 1.7 1.9 2.0 3.1 2.6 16 18 21 21 21 91 295 388 81 18 10 10 10 13 17 21 27 23 17 139 12 11 9 28 14 11 7 5 4 21 13 .09 .11 .11 .13 .17 7.9 28 75 1.0 .16 .08 .07 .08 .10 .14 .20 .24 .19 .12 5.7 .07 .06 .05 .16 .06 .06 .03 .02 .02 .25 .10 MEAN DISCHARGE (CPS) 2.5 6.9 4.5 2.4 2.2 2.1 2.1 2.3 2.2 2.3 2.3 2.4 2.2 2.2 2.4 2.4 2.3 2.4 2.3 2.3 2.8 2.3 2.0 2.0 1.9 4.1 6.4 4.3 1.7 1.5 MEAN CONCEN- TRATION (MG/L) JUNE 10 97 85 33 21 14 9 7 5 4 5 7 10 13 12 10 8 7 7 10 17 9 14 21 27 67 140 90 25 16 SEDIMENT DISCHARGE (TONS /DAY) .06 6.1 1.8 .22 .13 .08 .05 .04 .03 .03 .03 .05 .06 .08 .08 .06 .05 .05 .04 .07 .16 .05 .08 .11 .14 3.4 16 2.7 .12 .06 TOTAL 85.9 58.65 112.4 120.47 81.7 31.93 248 RIO GRANDB DE LOIZA BASIN 50055390 RIO BAIROA AT BAIROA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) 1.7 1.3 1.6 1.6 1.6 1.6 2.1 1.8 1.7 1.8 3.6 3.3 15 7.0 3.3 2.7 2.6 3.5 3.6 e8.5 5.6 e50 8.1 6.2 3.2 2,1 16 7.9 4.0 3.9 2.6 JULY 11 28 91 76 38 20 14 10 8 6 78 42 160 82 22 11 7 6 19 188 123 649 197 33 15 9 390 195 32 69 14 TOTAL 179.5 --- YEAR e 2550.5 Estimated MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) AUGUST .05 .10 .41 .32 .17 .09 .08 .05 .04 .03 1.8 .51 28 4.9 .23 .08 .05 .05 .27 e!3 3.3 «143 5.1 .54 .14 .05 29 6.9 .38 1.6 .10 240.34 3546.21 2.5 2.5 32 5.8 3.6 3.3 3.0 3.1 2.9 2.8 2.8 2.4 2.3 2.0 2.2 4.7 3.2 74 27 4.9 3.4 3.9 5.5 6.7 4.7 3.1 2.9 2.5 2.4 2.4 3.6 228.1 12 11 411 42 17 12 8 7 6 5 5 5 4 4 4 119 19 606 648 39 12 52 137 201 69 16 12 10 11 15 91 ... .08 .07 68 .73 .17 .11 .07 .06 .05 .04 .04 .03 .03 .02 .02 4.4 .16 276 61 .57 .11 .98 3.9 6.6 1.0 .14 .09 .06 .07 .11 3.1 427.81 MEAN DISCHARGE (CPS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) SEPTEMBER 2.3 2.2 2.0 1.9 14 232 77 51 34 33 25 19 16 18 38 162 56 22 12 9.0 7.9 5.6 6.5 5.2 4.5 4.5 11 4.4 4.2 3.7 885.9 9 7 7 6 232 574 249 86 42 38 99 46 15 6 623 1080 86 27 27 123 50 15 260 66 10 5 135 34 11 9 ... .05 .04 .03 .03 24 852 61 12 3.8 2.9 10 2.4 .74 .27 90 563 13 1.6 .86 4.1 1.0 .22 5.2 .93 .13 .06 13 .44 .12 .09 --- 1663.01 RIO GRANDE DE LOIZA BASIN 50055J90 RIO BAIROA AT BAIROA, PR—Continued HATER QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT 249 DATE OCT 1994 08... 08. .. 22... NOV 25. .. DEC 03. .. FEB 28... APR 15... HAY 08... SEP 06. .. DATE OCT 1994 08.. . 08.. . 22.. . NOV 25.. . DEC 03... FEB 28.. . APR 15... MAY 08.. . SEP 06.. . TIME 1354 1600 0905 1137 1633 1337 1445 1516 0719 SED. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 82 84 83 82 95 -- 86 75 78 DIS- CHARGE, INST. CUBIC FEET PER SECOND 84 11 95 74 29 69 75 60 655 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 87 90 88 89 — 84 90 83 84 SEDI- MENT, SUS- PENDED (MG/L) 6136 849 2394 3908 1392 5116 5970 5285 4217 SBD. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 99 95 97 99.1 99.5 92 98 95 93 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 1390 25 614 781 109 953 1210 856 7460 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 99.8 96 99.7 99.8 99.6 96 99 98 97 SED. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 50 76 64 57 84 48 58 53 56 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 99.9 96.8 99.9 99.9 99.9 97 99.6 98.9 99 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 60 80 70 64 91 53 65 57 64 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99.9 97.1 100 100 100 98 99.8 99.1 99.6 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 71 85 72 68 93 62 75 64 71 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 100 97.2 100 100 100 99 99.9 99.5 99.9 250 RIO GRANDE DE LOIZA BASIN 50055390 RIO BAIROA AT BAIROA, PR—Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DATE OCT 1994 08.. . 19. .. 22.. . 22.. . NOV 29... FEB 1995 21.. . 28. . . 28.. . 28.. . APR 15.. . HAY 06... 07... 20.. . JUN 27... JUL 03.. . 27.. . AUG 03.. . 31.. . SEP 05.. . 07.. . 27... TIME 1510 1717 1835 2206 1543 1605 1412 1452 1736 1630 1822 1609 1617 2010 1725 1605 0444 1729 1522 1956 1412 STREAM- FLOW, INSTAN- TANEOUS (CFS) 27.0 13.0 35.0 105 105 58.0 115 99.0 115 76.0 62.0 76.0 2.20 88.0 1.40 31 9.50 2.70 38.0 94.0 120 SEDI- MENT, SUS- PENDED (MG/L) 1080 785 26200 1600 1940 1200 1170 532 1310 1960 692 4080 157 2960 126 479 2010 361 825 552 797 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 79 28 2480 454 550 188 363 142 407 402 116 837 0.93 703 0.48 40 52 2.6 85 140 258 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 97 99 99.7 95 99 94 99 99 99 98 97 99 98 99 96 96 98 99 70 99 95 251 RIO GRANDE DE LOIZA BASIN 50055400 RIO BAIROA NEAR CAGUAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°15'28", long 66°02'13", at bridge on Highway 1, about 2.5 mi (4.0 km) upstream from Rio Grande de Loiza, and 1.4 mi (2.3 km) north of Caguas plaza. DRAINAGE AREA.--5.4 mi 1 (14.0 km1 ). PERIOD OF RECORD.--Water years 1958, 1962-66, 1973-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 11. .. DEC 12. .. FEB 1995 08. .. APR 07. .. •TON 08. .. AUG 16. .. DATE OCT 1994 11. .. DEC 12. .. FEB 1995 08. . . APR 07. .. •TON 08. . . AUG 16. .. DATE OCT 1994 11. .. DEC 12... FEB 1995 08. . . APR 07. . . JtJN 08. . . AUG 16. .. TIME 1020 0950 1035 0900 1045 0825 HARD- NESS TOTAL (MG/L AS CAC03) 170 -- -- 130 -- 160 SILICA, DIS- SOLVED (MG/L AS SI02) 33 — __ 24 — 31 DIS- CHARGE, INST. CUBIC FEET PER SECOND 3.2 3.1 2.5 2.2 2.0 1.2 CALCIUM DIS- SOLVED (MG/L AS CA) 43 -- -- 34 __ 40 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 274 __ __ 219 -- 266 SPE- CIFIC CON- DUCT- ANCE (US /CM) 456 459 418 363 480 482 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 16 — — 11 — 15 SOLIDS, DIS- SOLVED (TONS PER DAY) 2.34 -- __ 1.33 -- 0.85 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.2 7.2 7.5 7.2 7.2 7.2 SODIUM, DIS- SOLVED (MG/L AS NA) 30 -_ -- 23 -- 29 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 22 6 5 34 10 5 TEMPER- ATURE WATER (DEG C) 26.5 24.0 24.0 26.0 26.0 27.0 SODIUM AD- SORP- TION RATIO 1 — — 0.9 — 1 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 1.4 0.60 0.80 1.2 0.47 0.84 TUR- BID- ITY (NTU) 2.0 2.6 1.9 13 1.7 1.4 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 5.0 __ -- 4.1 -- 5.0 PHOS- PHORUS TOTAL (MG/L AS P) 0.510 0.440 0.640 0.470 0.430 0.450 OXYGEN, DIS- SOLVED (MG/L) 2.6 4.4 3.2 4.0 5.0 1.2 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 150 160 150 120 160 150 ARSENIC TOTAL (UG/L AS AS) 3 -- _- 2 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 32 51 37 49 61 15 SULFIDE TOTAL (MG/L AS S) <0.5 __ -- <0.5 -- — — BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- __ <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 11 18 13 50 12 12 SULFATE DIS- SOLVED (MG/L AS SO4) 20 -- -- 17 -- 16 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 60 __ — 50 — -- COLI- FORM, FECAL, 0.45 UM-MF (COLS. / 100 ML) 480000 60000 K86000 350000 7400 K8900 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 37 -_ -- 34 -- 40 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 57000 9700 K23000 360000 900 K1500 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.20 _- -- 0.10 __ 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 3 -- -- 7 — __ K = non-ideal count 252 RIO GRANDE DE LOIZA BASIN 50055400 RIO BAIROA NEAR CAGDAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 11. .. DEC 12. .. FEB 1995 08. .. APR 07. .. JUN 08. . . AUQ 16. . . COPPER, TOTAL RECOV- ERABLE (UQ/L AS CU) <10 IRON, TOTAL RECOV- ERABLE (UQ/L AS FE) 830 LEAD, TOTAL RECOV- ERABLE (UQ/L AS PB) 1 MANGA- NESE, TOTAL RECOV- ERABLE (UQ/L AS MN) 100 MERCURY TOTAL RECOV- ERABLE (UQ/L AS HO) <0.10 SELE- NIUM, TOTAL (UQ/L AS SB) <± SILVER, TOTAL RECOV- ERABLE (UQ/L AS AQ) <± ZINC, TOTAL RECOV- ERABLE (UQ/L AS ZN) 20 CYANIDE TOTAL (MQ/L AS CN) <0.010 PHENOLS TOTAL (UQ/L) <± METHY- LENE BLUE ACTIVE SUB- STANCE (MQ/L) 0.26 20 2100 200 <0.10 40 <0.010 4 0.55 RIO GRANDE DE LOIZA BASIN 50055750 RIO GURABO BELOW EL MANGO, PR LOCATION.--Lat 18°14'02», long 65°53'07«, Hydrologic Unit 21010005, on left bank, 2.43 mi (3.91 km) northeast of Plaza de Juncos, 1.3 mi (2.1 km) southeast of Escuela La Placita and 0.35 mi (0.56 km ) southwest of El Mango. 253 DRAINAGE AREA.--22.3 mi 1 (57.8 km2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 230 ft (70 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. Low-flow is affected by sewage discharges from a water treatment plant, 0.60 mi (0.96m) upstream from gaging station since 1990. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT DEC AUG 1 9.0 7.1 2 8.4 6.1 3 8.2 5.1 4 8.0 6.6 5 7.7 12 6 7.6 391 7 8.5 53 8 8.3 39 9 7.9 66 10 7.9 219 11 8.9 112 12 8.8 25 13 7.5 14 14 7.1 10 15 24 8.9 16 10 8.1 17 7.7 7.2 18 8.7 6.7 19 9.4 5.8 20 41 33 21 15 81 22 11 28 23 299 11 24 552 8.0 25 130 48 26 31 89 27 18 103 28 14 36 29 11 e!30 30 9.0 314 31 7.8 --- TOTAL 1312.4 1883.6 MEAN 42.3 62.8 MAX 552 391 MIN 7.1 5.1 AC-FT 2600 3740 CFSM 1.90 2.82 IN. 2.19 3.14 153 446 145 61 42 28 21 12 10 8.3 7.6 8.3 8.0 6.7 6.2 5.8 5.1 4.7 4.4 4.4 4.9 4.6 7.5 6.0 5.5 5.5 5.0 5.5 5.0 4.0 3.9 1044.9 33.7 446 3.9 2070 1.51 1.74 3.8 3.9 4.2 6.4 4.7 4.4 3.5 3.2 3.3 3.6 3.8 7.4 8.8 6.3 4.5 4.0 3.6 3.2 3.3 3.1 2.8 2.8 2.8 2.9 2.9 37 11 24 9.6 6.6 5.2 196.6 6.34 37 2.8 390 .28 .33 STATISTICS OF MONTHLY MEAN DATA FOR WATER MEAN 50.7 75.9 MAX 161 109 (WY) 1991 1992 MIN 4.01 35.5 (WY) 1993 1991 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 34.9 59.0 1991 12.0 1994 FOR 30.4 65.8 1992 6.34 1995 4.0 3.7 3.5 3.2 3.1 3.0 2.9 7.7 4.9 13 6.2 4.5 3.7 3.1 2.9 3.8 4.8 5.3 7.5 7.7 120 26 9.9 7.1 1060 152 138 257 ___ ___ —— 1868.5 66.7 1060 2.9 3710 2.99 3.12 YEARS 1990 32.2 66.7 1995 10.4 1993 40 20 14 13 14 15 12 22 13 12 9.2 32 27 24 12 8.1 7.1 6.8 6.3 6.1 6.4 6.1 6.0 5.9 6.2 6.4 6.4 6.4 6.1 5.8 5.7 381.0 12.3 40 5.7 756 .55 .64 - 1995 12.3 18.1 1991 5.63 1993 1994 CALENDAR YEAR 9266. 25. 839 3. 3. 18380 1. 15. 40 8. 4. 2 4 Sep 20 3 Jul 12 7 May 27 14 46 9 6 5.7 5.5 5.7 4.9 5.0 5.4 5.6 5.7 4.9 4.8 4.8 21 9.0 5.6 4.4 14 6.6 5.0 4.2 3.7 3.5 3.2 2.7 2.5 2.5 2.8 2.6 2.5 2.5 2.3 --- 158.6 5.29 21 2.3 315 .24 .26 2.2 2.2 2.2 2.3 6.3 4.4 3.4 4.2 3.6 3.5 3.0 2.6 2.3 2.0 1.9 2.5 2.6 2.5 2.8 5.9 3.8 3.2 3.0 2.6 2.7 4.0 9.4 24 26 57 29 227.1 7.33 57 1.9 450 .33 .38 24 105 433 38 17 11 21 12 6.4 32 70 29 24 16 277 292 37 15 13 11 11 12 9.6 8.3 7.2 6.6 7.6 13 7.9 7.0 —— 1573.6 52.5 433 6.4 3120 2.35 2.63 6.5 6.0 5.6 17 14 17 11 8.2 8.1 5.9 5.1 15 11 21 41 39 22 13 12 7.6 18 117 21 12 7.6 7.9 374 63 44 36 24 1010.5 32.6 374 5.1 2000 1.46 1.69 21 57 434 39 18 14 15 16 15 8.8 7.3 5.7 4.9 4.4 3.9 3.8 9.9 219 326 44 46 202 27 24 40 17 12 10 9.2 8.9 10 1672.8 54.0 434 3.8 3320 2.42 2.79 8.2 6.8 6.5 6.1 166 1210 111 43 28 22 22 22 19 17 246 1570 475 101 42 155 51 31 175 43 26 45 27 20 73 28 --- 4795.6 160 1570 6.1 9510 7.17 8.00 , BY WATER YEAR (WY) 8.70 11.0 1993 5.29 1995 FOR 1995 16125 44 1570 1 2 4460 16 31980 1 26 94 8 3 32.5 123 1992 4.83 1990 WATER YEAR .2 .2 Sep 16 .9 May 15 .3 Apr 28 Feb 25 .42 Feb 25 .98 .90 .3 .2 50.6 117 1992 14.7 1991 43.0 147 1993 6.74 1994 WATER 40 52 22 1710 1 1 5870 17 29350 1 24 73 10 3 29.7 54.0 1995 10.2 1993 YEARS 1990 .5 .3 .0 Jul .1 Oct .4 Oct Nov .38 Nov .82 .68 .8 67.7 160 1995 34.9 1990 - 1995 1992 1994 11 1993 27 1992 22 1992 8 1991 8 1991 e Estimated 254 RIO GRANDE DE LOIZA BASIN 50055750 RIO GURABO BELOW EL MANGO, PR—Continued WATER-QUALITY RECORDS PERIOD OP RECORDS.-- Water year 1990 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: March 1990 to September 1995. INSTRtFMENTATION.--Automatic sediment sampler since 1990. REMARKS:— Sediment samples were collected by a local observer on a weekly basis and during high flow events EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,000 mg/L Oct. 21, 1990; Minimum daily mean, 4 mg/L April 7,1991. SEDIMENT LOADS: Maximum daily mean, 7,110 tons (6,450 tonnea) Nov. 08, 1991; Minimum daily mean, 0.05 ton (0.3 tonne) several days. EXTREMES FOR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATION: Maximum daily mean, 615 mg/L September 06, 1995; Minimum daily mean, 6 mg/L May 3, 1995. SEDIMENT LOADS: Maximum daily mean, 3,010 tons (2,730 tonnes) September 06, 1995; Minimum daily mean, 0.04 ton (0.04 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) OCTOBER 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 9.0 8.4 8.2 8.0 7.7 7.6 8.5 8.3 7.9 7.9 8.9 8.8 7.5 7.1 24 10 7.7 8.7 9.4 41 15 11 299 552 130 31 18 14 11 9.0 7.8 35 38 40 42 45 47 50 52 50 46 43 39 37 33 67 41 34 33 33 96 54 44 445 486 204 87 73 67 62 56 52 .87 .85 .88 .91 .93 .97 1.1 1.2 1.1 .98 1.0 .93 .74 .63 5.0 1.1 .71 .77 .85 14 2.1 1.3 499 939 89 7.5 3.6 2.5 1.8 1.4 1.1 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) NOVEMBER 7.1 6.1 5.1 6.6 12 391 53 39 66 219 112 25 14 10 8.9 8.1 7.2 6.7 5.8 33 81 28 11 8.0 48 89 103 36 e!30 314 47 43 40 34 37 310 110 89 134 262 190 65 51 49 47 45 43 41 39 80 155 74 37 28 101 169 198 75 170 436 . . 2. 707 17 10 28 348 73 4. 1. 1. 1. . 58 47 6. 1. . 23 79 68 7. el!4 451 - 91 72 55 61 0 6 9 4 1 98 84 75 61 6 1 61 3 -- 153 446 145 61 42 28 21 12 10 8. 7. 8. 8. 6. 6. 5. 5. . . . 7. 6. 5. 5. 5. 5. 5. 4. 3. DECEMBER 3 6 3 0 7 2 8 1 7 4 4 9 6 5 0 5 5 0 5 0 0 9 247 481 245 116 94 78 64 55 52 50 48 46 44 43 41 43 45 47 50 52 55 56 52 47 43 39 36 33 30 28 26 242 718 120 19 11 5.8 3.2 1.7 1.4 1.1 .99 1.0 .96 .77 .70 .67 .63 .61 .59 .62 .72 .69 1.0 .77 .64 .59 .49 .49 .41 .30 .27 1312.4 1583.82 1883.6 2055.58 1044.9 1137.11 e Estimated 255 RIO GRANDE DE LOZZA BASIN 50055750 RIO GURABO BELOW EL MANGO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 3.8 3.9 4.2 6.4 4.7 4.4 3,5 3.2 3.3 3.6 3.8 7.4 8.8 6.3 4.5 4.0 3.6 3.2 3.3 3.1 2.8 2.8 2.8 2.9 2.9 37 11 24 9.6 6.6 5.2 24 22 20 18 17 17 16 16 16 16 15 20 36 29 32 37 43 50 58 68 76 66 55 45 37 63 56 51 50 50 49 .24 .23 .22 .32 .22 .20 .15 .14 .14 .15 .16 .52 .85 .50 .39 .40 .42 .44 .53 .57 .56 .50 .41 .35 .29 15 1.7 3.2 1.3 .86 .69 4 3 3 3 3 3 2 7 4 13 6 4 3 3 2 3 4 5 7 7 120 26 9 7 1060 152 138 257 . - - MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) FEBRUARY .0 .7 .5 .2 .1 .0 .9 .7 .9 .2 .5 .7 .1 .9 .8 .8 .3 .5 .7 .9 .1 __ -- -- 49 49 49 49 49 48 48 48 48 48 48 48 49 49 46 42 40 38 37 35 206 83 35 27 563 215 218 282 ___ ___ .54 .49 .46 .42 .40 .39 .38 1.0 .64 1.7 .80 .59 .48 .40 .36 .43 .52 .55 .75 .73 152 6.8 .94 .52 3320 126 91 221 ___ ___ ___ 40 20 14 13 14 15 12 22 13 12 9. 32 27 24 12 8. 7. 6. 6. 6. 6. 6. 6. 5. 6. 6. 6. 6. 6. 5. 5. MARCH 2 1 1 8 3 1 4 1 0 9 2 4 4 4 1 8 7 136 71 47 44 39 45 41 58 39 33 33 76 72 67 42 29 26 25 25 25 24 24 24 23 23 23 22 22 22 21 21 15 3.9 1.8 1.5 1.5 2.0 1.3 3.7 1.4 1.1 .83 8.3 6.1 4.8 1.4 .64 .49 .47 .43 .40 .42 .39 .38 .38 .38 .39 .38 .38 .36 .34 .32 196.6 31.67 1868.5 3930.29 381.0 61.18 256 RIO GRANDE DE LOIZA BASIN 50055750 RIO GORABO BELOW EL MANGO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 5. 5. 5. 4. 5. 5. 5. 5. 4. 4. 4. 21 9. 5. 4. 14 6. 5. 4. 3. 3. 3. 2. 2. 2. 2. 2. 2. 2. 2. -- 7 5 7 9 0 4 6 7 9 8 8 0 6 4 6 0 2 7 5 2 7 5 5 8 6 5 5 3 - APRIL 21 20 20 21 25 28 33 37 43 49 55 66 33 25 20 43 42 38 36 34 33 32 30 29 28 23 19 16 13 11 ___ MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MAY .32 .30 .31 .28 .33 .41 .49 .58 .56 .64 .72 4.0 .82 .38 .24 1.9 .76 .51 .41 .35 .31 .27 .22 .20 .19 .17 .14 .11 .09 .07 ___ 2 2 2 2 6 4 3 4 3 3 3 2 2 2 1 2 2 2 2 5 3 3 3 2 2 4 9 24 26 57 29 .2 .2 .2 .3 .3 .4 .4 .2 .6 .5 .0 .6 .3 .0 .9 .5 .6 .5 .8 .9 .8 .2 .0 .6 .7 .0 .4 9 7 6 7 8 9 10 12 14 16 18 21 24 28 31 30 27 25 23 22 20 18 17 16 15 14 13 64 72 111 75 .05 .04 .04 .04 .13 .11 .10 .14 .14 .15 .15 .15 .15 .15 .16 .20 .19 .17 .18 .34 .20 .16 .14 .11 .11 .14 .34 5.4 5.4 28 6.5 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) JUNE 24 105 433 38 17 11 21 12 6.4 32 70 29 24 16 277 292 37 15 13 11 11 12 9.6 8.3 7.2 6.6 7.6 13 7.9 7.0 ___ 63 185 379 94 60 55 50 44 39 76 140 73 51 48 443 451 138 136 133 122 77 46 39 39 38 37 36 35 35 34 ___ 4.3 74 730 10 2.7 1.6 2.8 1.4 .67 34 34 6.2 3.3 2.1 468 523 13 5.7 4.6 3.7 2.3 1.4 1.0 .87 .74 .66 .75 1.3 .74 .64 ___ TOTAL 158.6 16.08 227.1 49.28 1573.6 1935.47 257 RIO GRANDE DE LOIZA BASIN 50055750 RIO GORABO BELOW EL MANGO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN DISCHARGE DAY 1 2 3 4 5 6 7 e 9 10 11 12 13 14 15 16 17 IB 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR (CPS) 6.5 6.0 5.6 17 14 17 11 8.2 8.1 5.9 5.1 15 11 21 41 39 22 13 12 7.6 18 117 21 12 7.6 7.9 374 63 44 36 24 1010.5 16125.2 MEAN CONCEN- TRATION (MG/L) JULY 33 33 32 31 31 30 29 27 20 16 12 11 15 56 85 103 69 49 34 25 76 201 61 41 35 31 215 178 157 134 92 —— SEDIMENT DISCHARGE (TONS/DAY) .58 .52 .48 1.4 1.2 1.4 .88 .59 .45 .25 .17 .45 .95 3.6 19 11 4.1 1.7 1.1 .50 31 120 3.6 1.4 .72 .65 329 30 19 12 6.1 603.79 20521.24 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) AUGUST 21 57 434 39 18 14 15 16 15 8.8 7.3 5.7 4.9 4.4 3.9 3.8 9.9 219 326 44 46 202 27 24 40 74 273 384 104 53 25 22 20 19 18 17 17 16 14 11 11 37 248 325 109 102 322 89 68 92 9 50 1050 12 2 1 498 333 13 16 282 6 4 11 .4 .5 .94 .81 .85 .77 .43 .34 .26 .22 .16 .12 .11 .3 .7 .3 17 12 10 9.2 8.9 10 1672.8 55 39 28 30 30 29 2.6 1.2 .78 .75 .72 .81 2301.07 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) SEPTEMBER 8.2 6.8 6.5 6.1 166 1210 . Ill 43 28 22 22 22 19 17 246 1570 475 101 42 155 51 31 175 43 26 45 27 20 73 28 4795.6 28 27 26 26 170 615 132 57 45 36 31 34 33 32 166 266 395 184 103 167 118 63 245 169 80 98 79 62 138 90 221 3010 48 6. 3. 2. 1. 2. 1. 1. 824 1460 528 55 12 211 16 5. 316 20 5. 15 5. 3. 31 7. 62 50 46 42 7 5 2 9 0 7 4 8 5 6 4 2 6815.90 258 RIO GRANDE DE LOIZA BASIN 50055750 RIO GORABO BELOW EL MANGO, PR—Continued HATER QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT 1995 DATE NOV 1994 30. .. AUG 1995 03. .. TIME 1400 0646 DIS- CHARGE, INST. CUBIC FEET PER SECOND 333 2550 SEDI- MENT, SUS- PENDED (MG/L) 1345 3123 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 1210 21500 SED. SED. SUSP. SUSP. FALL FALL DIAM. DIAM. PERCENT PERCENT FINER FINER THAN THAN .002 MM .004 MM 76 52 81 69 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 84 68.5 DATE NOV 1994 30. .. AUG 1995 03. .. SED. SUSP. FALL DIAM. PERCENT FINER THAN 016 MM 87 77 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 89 84 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 97 97 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 99 99 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 99.6 99.7 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99.8 99.8 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 100 99.9 259 RIO GRANDE DE LOIZA BASIN 50055750 RIO GURABO BELOW EL MANGO--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DATE OCT 1994 23... 23... 23.. . NOV 26. . . 30.. . 30.. . FEB 1995 28. . . 28.. . JUN 02... JUL 21... 27.. . AU6 03... 18. .. 19... SEP 05.. . 15... 27.. . TIME 0346 0357 0402 1315 1504 1714 0629 0703 1530 2330 1400 1330 2018 1105 1922 2200 1230 STREAM- FLOW, INSTAN- TANEOUS (CFS) 496 504 512 20 557 333 462 567 120 40 746 352 1133 671 735 1330 26 SEDI- MENT, SUS- PENDED (MG/L) 585 496 436 182 720 590 174 167 261 633 735 582 742 916 1140 597 153 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 783 675 603 10 1080 530 217 256 64 68 1480 553 2270 1660 2260 2140 10 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 99 95 98 73 99 99 99 99 98 99 72 97 99 97 99 99 95 260 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR LOCATION.--Lat 18°12'58", long 65°55'34", Hydrologic Unit 21010005, on left bank at Highway 919, 0.5 mi (0.8 km) upstream from Quebrada Don Victor, 1.7 mi (2.7 km) upstream from Rio Gurabo and 1.0 mi (1.6 km) south of Juncos. DRAINAGE AREA.--16.4 mi 2 (42.5 km 2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1971 to current year. GAGE.--Water-stage recorder. Elevation of gage is 320 ft (98 m), from topographic map. REMARKS.--Records poor. Minor diversion from public water supply tank, 0.5 mi upstream, during low flow. Gage-height and precipitation satellite telemetry at station. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate discharges (no stages were recorded) of major floods are as follows: Sept. 6, 1960, 37,100 ftVs (1,050 mVs), Oct. 9, 1970, 18,200 ftVs (515 m3/s) . DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 8.9 9.2 2 8.4 9.1 3 8.3 8.8 4 7.6 10 5 7.3 10 6 7.4 52 7 8.0 26 8 7.2 16 9 7.2 31 10 7.4 24 11 6.9 30 12 6.3 15 13 6.9 12 14 6.4 11 15 6.3 9.9 16 6.6 9.4 17 6.7 8.5 18 13 8.7 19 8.9 8.3 20 9.8 17 21 7.8 88 22 15 15 23 374 11 24 129 9.2 25 106 45 26 27 97 27 16 88 28 12 26 29 11 94 30 9.9 54 31 9.4 —— TOTAL 872.6 853.1 MEAN 28.1 28.4 MAX 374 97 MIN 6.3 8.3 AC-FT 1730 1690 CFSM 1.72 1.73 IN. 1.98 1.94 STATISTICS OF MONTHLY MEAN MEAN 74.7 89.6 MAX 293 461 (WY) 1986 1988 MIN 19.9 19.5 (WY) 1993 1990 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 44 128 60 31 23 17 16 13 12 12 12 12 18 12 11 12 12 11 11 11 11 13 13 11 11 12 10 10 10 9.9 9.8 598.7 19.3 128 9.8 1190 1.18 1.36 DATA 55.2 550 1988 11.0 1990 FOR 10 11 11 12 10 10 10 10 11 11 11 12 16 13 11 11 11 11 11 10 9.5 9.6 10 11 11 55 15 12 11 8.8 8.1 384.0 12.4 55 8.1 762 .76 .87 FOR WATER 22.9 77.0 1992 11.4 1976 8.0 7.9 7.2 7.5 7.6 7.6 7.8 11 9.9 30 12 11 9.5 9.3 9.6 11 12 11 11 12 138 43 18 18 194 59 32 26 ___ ___ —— 740.9 26.5 194 7.2 1470 1.61 1.68 YEARS 1971 18.5 47.9 1984 7.21 1974 16 20 14 23 48 17 13 13 39 16 11 10 13 12 8.5 8.0 7.3 6.8 6.8 6.4 6.2 6.1 5.9 5.6 5.4 5.0 4.9 4.8 4.9 4.5 4.7 366.8 11.8 48 4.5 728 .72 .83 - 1995 19.1 39.7 1973 7.01 1977 1994 CALENDAR YEAR 7090. 19. 1240 1. 1. 14060 1. 16. 29 9. 2. 8 4 Sep 20 4 Jul 15 7 Jul 10 18 08 8 4 5.0 4.7 4.6 4.5 5.6 5.2 6.0 6.1 5.1 4.9 5.1 28 6.6 5.5 4.5 8.4 4.8 4.2 3.8 4.2 3.7 3.7 3.7 3.5 2.8 2.4 2.3 2.2 2.0 1.9 —— 155.0 5.17 28 1.9 307 .32 .35 2.0 1.8 1.9 2.0 2.5 3.9 3.2 3.7 6.8 3.5 2.8 2.6 2.2 1.9 1.9 2.3 3.2 2.3 3.5 17 8.4 4.8 3.4 2.7 3.1 5.1 13 6.5 11 25 18 172.0 5.55 25 1.8 341 .34 .39 192 e365 597 113 51 54 49 36 25 24 27 34 25 43 403 253 81 43 33 28 32 25 22 20 19 20 19 21 19 18 --- 2691 89.7 597 18 5340 5.47 6.10 18 18 18 17 62 34 29 25 21 19 20 72 27 25 97 46 27 17 14 12 13 19 12 11 9.8 9.3 426 59 64 72 43 1356.1 43.7 426 9.3 2690 2.67 3.08 26 23 305 40 24 20 19 27 20 17 15 14 13 13 12 12 21 234 211 35 90 204 40 31 49 24 19 17 16 15 15 1621 52.3 305 12 3220 3.19 3.68 14 13 13 13 79 702 98 69 40 28 41 49 26 21 184 870 394 108 55 368 98 50 44 37 32 68 39 32 39 31 3655 122 870 13 7250 7.43 8.29 , BY WATER YEAR (WY) 14.8 41.7 1985 5.17 1995 FOR 1995 13466 36 870 1 2 3180 9 26710 2 30 68 12 4 50.2 268 1985 5.02 1990 WATER YEAR .2 .9 Sep 16 . 8 May 2 .0 Apr 28 Jun 3 .43 Jun 3 .25 .55 .5 50.4 188 1979 4.95 1994 46.9 163 1981 4.61 1994 WATER 48 121 17 9100 1 1 40000 25 1 35220 2 40 71 18 6 59.7 231 1979 4.71 1994 YEARS 1971 - .6 .1 Dec 8 .4 Jul 15 .7 Jul 10 Dec 8 .63 Dec 8 .4 Apr 21 .96 .28 .8 79.3 255 1979 10.8 1987 1995 1988 1990 1987 1994 1994 1987 1987 1988 e Estimated RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1983 to 1986 and water year 1989 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1994 to September 1995. INSTRUMENTATION.-- Automatic sediment sampler since 1984. REMARKS:— Sediment samples were collected by a local observer on a weekly basis and during high flow events. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,600 mg/L Oct. 06, 1985; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 46,300 tons (42,000 tonnes) May 18, 1985; Minimum daily mean, 0.01 ton (0.01 tonne) several days. EXTREMES FOR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1090 mg/L September 16, 1995; Minimum daily mean, 4 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 3,400 tons (3,080 tonnes) September 16, 1995; Minimum daily mean, 0.02 tons (0.02 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 261 MEAN MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE >AY (CFS) (MG/L) (TONS/DAY) OCTOBER 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 8.9 8.4 8.3 7.6 7.3 7.4 8.0 7.2 7.2 7.4 6.9 6.3 6.9 6.4 6.3 6.6 6.7 13 8.9 9.8 7.8 15 374 129 106 27 16 12 11 9.9 9.4 9 7 7 7 8 8 8 8 9 10 11 13 14 16 18 19 20 26 18 25 18 42 936 323 246 50 16 12 10 11 13 .22 .16 .16 .15 .15 .15 .17 .16 .17 .20 .21 .21 .27 .27 .30 .34 .36 .89 .48 .66 .38 2.3 2930 142 101 3.9 .68 .40 .31 .30 .33 MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) NOVEMBER 9.2 9.1 8.8 10 10 52 26 16 31 24 30 15 12 11 9.9 9.4 8.5 8.7 8.3 17 88 15 11 9.2 45 97 88 26 94 54 15 17 19 24 20 120 64 37 98 176 77 34 28 23 17 12 8 6 4 44 238 37 25 19 117 240 243 64 214 162 .36 .41 .45 .73 .54 40 4.8 1.7 10 12 8.0 1.3 .91 .66 .45 .31 .19 .14 .09 5.4 143 1.5 .76 .47 30 137 72 4.9 91 24 MEAN DISCHARGE (CFS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) 44 128 60 31 23 17 16 13 12 12 12 12 18 12 11 12 12 11 11 11 11 13 13 11 11 12 10 10 10 9.9 9.8 DECEMBER 111 285 222 81 51 29 16 20 19 18 17 16 40 21 11 11 12 13 15 16 17 19 17 15 14 12 11 10 9 9 9 25 136 44 7.1 3.2 1.4 .68 .71 .64 .57 .54 .53 2.2 .67 .34 .35 .38 .39 .43 .48 .52 .63 .58 .47 .41 .39 .32 .28 .25 .24 .23 TOTAL 872.6 3187.28 853.1 593.07 598.7 229.93 262 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JDNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) JANUARY MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) FEBRUARY MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MARCH 10 11 11 12 10 10 10 10 11 11 11 12 16 13 11 11 11 11 11 10 9.5 9.6 10 11 11 55 15 12 11 8.8 8.1 9 8 8 8 8 8 8 8 7 7 7 10 47 29 24 19 15 12 10 8 6 7 8 8 10 137 43 35 32 29 26 .24 .24 .24 .25 .22 .22 .22 .21 .22 .21 .20 .34 2.3 1.0 .71 .55 .45 .34 .27 .21 .16 .17 .20 .25 .29 33 1.7 1.2 .91 .69 .57 8.0 7.9 7.2 7.5 7.6 7.6 7.8 11 9.9 30 12 11 9.5 9.3 9.6 11 12 11 11 12 138 43 18 18 194 59 32 26 24 22 20 18 16 15 13 12 12 75 24 17 12 9 10 14 16 18 21 24 364 116 47 45 248 152 92 67 .51 .46 .38 .36 .33 .30 .28 .36 .33 8.0 .79 .48 .32 .23 .27 .40 .51 .54 .64 .75 206 18 2.7 2.3 599 35 10 4.8 16 20 14 23 48 17 13 13 39 16 11 10 13 12 8.5 8.0 7.3 6.8 6.8 6.4 6.2 6.1 5.9 5.6 5.4 5.0 4.9 4.8 4.9 4.5 4.7 26 43 28 50 130 51 40 32 102 46 25 21 29 23 17 9 8 7 7 7 6 6 6 5 5 5 5 4 4 4 4 1.1 2.5 1.1 8.6 22 2.4 1.4 1.1 13 2.0 .77 .57 1.1 .73 .38 .19 .15 .13 .13 .11 .11 .10 .09 .08 .07 .07 .06 .06 .05 .05 .05 TOTAL 384.0 47.78 740.9 894.04 366.8 60.25 263 RIO GRANDE OE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JTJNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 5. 4. 4. 4. 5. 5. 6. 6. 5. 4. 5. 28 6. 5. 4. 8. 4. 4. 3. 4. 3. 3. 3. 3. 2. 2. 2. 2. 2. 1. -- 0 7 6 5 6 2 0 1 1 9 1 6 5 5 4 8 2 8 2 7 7 7 5 8 4 3 2 0 9 - APRIL 4 4 5 5 5 5 5 5 6 6 7 69 17 13 9 23 26 24 20 16 13 10 8 6 5 5 5 5 4 4 ___ MEAN MEAN CONCEN- SEDIMENT MEAN DISCHARGE TRATION DISCHARGE DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) MAY .06 .06 .06 .06 .07 .07 .08 .09 .08 .08 .10 8.7 .31 .19 .11 .54 .34 .27 .20 .18 .13 .10 .08 .06 .04 .03 .03 .03 .02 .02 ___ 2. 1. 1. 2. 2. 3. 3. 3. 6. 3. 2. 2. 2. 1. 1. 2. 3. 2. 3. 17 8. 4. 3. 2. 3. 5. 13 6. 11 25 18 0 8 9 0 5 9 2 7 8 5 8 6 2 9 9 3 2 3 5 4 8 4 7 1 1 5 4 5 5 5 5 5 5 6 6 6 7 7 8 8 40 20 12 10 9 7 10 31 13 24 59 43 .02 .02 .02 .02 .03 .05 .04 .05 .09 .05 .04 .04 .03 .03 .03 .04 .06 .05 .08 3.9 .52 .15 .09 .06 .06 .19 1.6 .24 .79 10 2.9 192 e365 597 113 51 54 49 36 25 24 27 34 25 43 403 253 81 43 33 28 32 25 22 20 19 20 19 21 19 18 ___ MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) JUNE 338 712 1020 309 130 64 30 25 23 21 19 70 59 154 755 522 233 110 82 74 67 61 55 50 45 43 42 41 41 40 ___ 366 e795 2120 102 18 9.5 4.0 2.4 1.5 1.4 1.4 6.7 4.0 21 1030 402 54 13 7.3 5.7 5.8 4.1 3.2 2.7 2.4 2.3 2.2 2.3 2.1 1.9 TOTAL 155.0 12.19 172.0 21.29 2691 4993.9 e Estimated 264 )AY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MEAN DISCHARGE (CPS) 18 18 18 17 62 34 29 25 21 19 20 72 27 25 97 46 27 17 14 12 13 19 12 11 9.8 9.3 426 59 64 72 43 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALBNCIANO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) JULY TOTAL 1356.1 YEAR 13466.2 39 38 37 37 153 96 69 50 30 18 23 152 170 72 191 145 65 26 10 14 17 43 25 16 10 6 395 134 107 167 116 —— 1.9 1.8 1.8 1.6 40 9.2 5.6 3.4 1.7 .91 1.5 39 21 6.5 129 22 5.7 1.2 .41 .46 .60 2.3 .83 .46 .25 .15 874 24 23 58 17 1295.27 24836.70 MEAN MEAN CONCEN- SEDIMENT MEAN DISCHARGE TRATION DISCHARGE DISCHARGE (CPS) (MG/L) (TONS/DAY) (CPS) AUGUST 26 23 305 40 24 20 19 27 20 17 15 14 13 13 12 12 21 234 211 35 90 204 40 31 49 24 19 17 16 15 15 58 50 435 47 18 15 13 48 26 19 16 14 11 10 8 7 139 971 521 96 198 409 10B 66 95 46 40 36 35 34 33 4.1 3.1 eoo 5.6 1.2 .79 .66 4.3 1.4 .87 .64 .50 .40 .33 .26 .23 16 2350 400 9.2 87 345 12 5.6 14 3.0 2.1 1.7 1.5 1.4 1.3 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) SEPTEMBER 14 13 13 13 79 702 98 69 40 28 41 49 26 21 164 870 394 108 55 368 98 50 44 37 32 68 39 32 39 31 ___ 32 31 30 29 200 831 190 276 234 149 127 245 81 59 390 1090 690 221 17 268 40 9 10 10 11 141 111 86 102 79 1.2 1.1 1.0 1.0 86 2690 52 52 25 11 22 33 5.8 3.4 941 3400 842 73 2.7 1080 14 1.3 1.2 1.0 .92 49 12 7.3 11 6.6 ___ 1621 4074.18 3655 9429.52 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR—Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1943 TO SEPTEMBER PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT 265 1995 DATE OCT 1994 23... 23. .. NOV 21. .. FEB 1995 25. .. JUN 03. .. TIME 0230 0350 0040 1950 0030 DIS- CHARGE, INST. CUBIC FEET PER SECOND 1700 2310 498 1620 iee SEDI- MENT, SUS- PENDED (MG/L) 14400 3792 2912 3409 6104 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 6610 23600 3915 14900 3100 SED. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 29 59 77 60 55 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 39 60 83 65 57 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 43 67 — 70 67 DATE OCT 1994 23... 23.. . NOV 21. . . FEB 1995 25.. . JUN 03.. . SED. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 53 75 88 75 77 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 65 80 92 82 84 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 80 94 98.8 91 97 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 94 98 99.4 97 99.1 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 98.6 99.3 99.7 98.9 99.6 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99.6 99.6 99.9 99.7 99.8 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 99.9 99.9 100 99.9 99.9 266 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR—Continued HATER QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DATE OCT 1994 23.. . 23... NOV 06... 06.. . 10. .. 21. . . 21.. . DEC 03.. . FEB 1995 15.. . 21... 21.. . 25.. . 26.. . OUN 02.. . 02... 03... 15.. . 15.. . JUL 27.. . 29.. . ADG 18.. . 19.. . SEP 18.. . 20.. . TIME 0215 0915 1305 1440 1336 0005 0300 1500 1115 0845 2000 2230 0030 1315 2040 0600 0105 0450 0705 0405 0600 0615 1545 2150 STREAM- PLOW, INSTAN- TANEOUS (CFS) 479 206 208 207 17.0 236 216 39.0 9.2 252 191 408 206 238 243 1610 233 714 212 208 26.0 512 86.0 357 SEDI- MENT, SUS- PENDED (MG/L) 7670 370 343 518 161 783 494 187 12 816 465 508 378 1340 1650 892 2270 623 680 86 464 693 195 409 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 9920 206 193 290 7.4 499 288 20 0.29 555 240 560 210 861 1080 3880 1430 1200 389 48 33 958 45 394 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 96 99 91 98 83 97 99.8 92 78 98 96 98 99.6 98 99 96 98 97 84 95 97 97 89 98 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO, PR LOCATION.--Lat 18°15'30", long 65°58'05", Hydrologic Unit 21010005, on left bank, at bridge on Highway 181, 0.3 mi (0.5 km) east of Gurabo, and 4.5 mi (7.6 km) upstream from Rio Grande de Loiza. 267 DRAINAGE AREA.--60.2 mi' (155.9 km2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1958 (occasional low-flow measurements only), January to September 1959 (monthly measurements only), October 1959 to current year. GAGE.—Water-stage recorder and crest-stage gage. Datum of gage is 131.58 ft (40.106 m) above mean sea level. Prior to Oct. 1, 1989 datum 5.0 ft (1.5 m) higher. REMARKS.—Records fair. Gage-height and precipitation satellite telemetry at station. Low flow affected by diversions for water supply about, 400 ft (121m) upstream from station by A.A.A. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT NOV JAN JUN AUG SEP 1 14 12 2 13 11 3 13 11 4 12 23 5 11 33 6 11 293 7 12 116 8 12 84 9 12 87 10 12 96 11 14 172 12 13 64 13 11 38 14 10 28 15 18 24 16 18 21 17 14 19 18 30 19 19 18 17 20 39 20 21 29 142 22 22 63 23 505 31 24 536 23 25 209 55 26 70 118 27 36 182 28 25 84 29 18 206 30 15 273 31 13 —— TOTAL 1785 2365 MEAN 57.6 78.8 MAX 536 293 MIN 10 11 AC-FT 3540 4690 CFSM .96 1.31 IN. 1.10 1.46 STATISTICS OF MONTHLY MEAN MEAN 219 216 MAX 1414 1045 (WY) 1971 1988 MIN 16.0 37.3 (WY) 1968 1974 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 116 370 263 106 83 64 53 35 29 25 23 23 28 23 21 19 17 17 16 15 16 16 21 21 18 17 18 18 15 13 12 1531 49.4 370 12 3040 .82 .95 12 13 13 16 15 14 12 12 12 15 14 18 20 19 15 10 9.7 9.8 13 14 15 17 17 15 19 71 44 42 27 17 17 577.5 18.6 71 9.7 1150 .31 .36 DATA FOR WATER 154 863 1988 10.7 1968 FOR 59.9 204 1992 16.4 1968 15 14 13 13 15 14 15 23 23 36 23 15 11 10 10 13 16 17 16 25 176 93 21 15 1230 301 129 205 ___ ___ --- 2507 89.5 1230 10 4970 1.49 1.55 YEARS 1960 46.7 131 1989 12.6 1968 82 49 35 28 54 31 29 31 39 36 22 33 38 41 29 19 16 15 14 14 14 13 11 11 13 12 13 13 13 14 12 794 25.6 82 11 1570 .43 .49 - 1995 39.4 97.5 1985 11.2 1965 1994 CALENDAR YEAR 15276. 41. 1870 6. 7. 30300 . 9. 81 18 9. 0 9 Sep 20 4 Apr 5 8 Feb 8 70 44 8 13 14 13 13 13 14 16 17 15 14 13 40 23 12 9.3 32 28 14 8.5 7.4 6.7 6.0 5.7 5.2 5.2 5.6 6.5 7.3 7.5 7.3 —— 392.2 13.1 40 5.2 778 .22 .24 5.9 6.7 7.3 7.0 10 12 10 8.3 12 14 11 9.1 8.3 9.3 6.7 25 15 5.3 4.5 12 22 9.0 6.7 6.1 5.2 5.4 15 14 41 38 70 431.8 13.9 70 4.5 856 .23 .27 72 233 629 132 57 46 42 41 22 16 56 50 35 24 334 301 105 49 30 24 27 21 16 13 12 12 12 15 12 9.6 --- 2447.6 81.6 629 9.6 4850 1.36 1.51 8.7 7.8 7.1 12 24 36 20 15 11 8.8 7.4 31 25 39 41 85 33 20 16 10 9.5 75 31 16 10 8.2 382 131 78 67 73 1338.5 43.2 382 7.1 2650 .72 .83 31 57 518 85 34 22 19 19 24 14 10 8.3 7.0 6.3 6.0 6.3 8.5 648 663 97 71 281 71 48 63 39 25 20 18 17 17 2953.4 95.3 663 6.0 5860 1.58 1.83 14 11 10 9.6 64 1760 201 107 65 42 36 47 31 23 127 2580 569 198 93 286 160 74 107 121 81 90 96 70 116 91—— 7279.6 243 2580 9.6 14440 4.03 4.50 , BY WATER YEAR (WY) 42.5 108 1978 13.1 1995 FOR 1995 24402 66 2580 4 5 6110 17 48400 1 15 119 18 8 148 746 1985 12.7 1990 WATER YEAR .6 .9 Sep 16 .5 May 19 .8 Apr 21 Feb 25 .21 Feb 25 .11 .08 .8 130 468 1970 16.8 1972 116 376 1993 20.7 1994 WATER 130 286 42 21100 4 5 21100 27 93940 2 29 205 48 17 165 610 1979 24.8 1967 YEARS 1960 .2 Sep .5 May .5 Sep Sep .70 Sep .15 .27 216 1225 1960 8.76 1967 - 1995 1979 1967 6 1960 19 1995 21 1967 6 1960 6 1960 268 RIO GRANDE DE LOZZA BASIN 50057000 RIO GURABO AT GURABO--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1984 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1983 to September 1995. INSTRUMENTATION.-- USD-49 sediment sampler, since 1984. Automatic sediment sampler, since 1984. REMARKS:-- Sediment samples were collected by a local observer on a weekly basis and during high flow events. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 9,220 mg/L Nov 27, 1987; Minimum daily mean, 3 mg/L August 09, 1994. SEDIMENT LOADS: Maximum daily mean, 686,000 tons (622,340 tonnes) Nov 27, 1987; Minimum daily mean, 0.08 tons (0.07 tonne) August 08, 1994. EXTREMES FOR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1070 mg/L September 16, 1995; minimum daily mean, 4 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 4,280 tons (3,880 tonnes) February 25, 1995; minimum daily 0.07 tons (0.06 tonne) May 01, 1995. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) OCTOBER 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 14 13 13 12 11 11 12 12 12 12 14 13 11 10 18 18 14 30 18 39 29 22 505 536 209 70 36 25 18 15 13 11 12 12 13 13 13 16 20 20 18 16 14 12 10 15 25 19 29 17 39 32 40 397 339 187 91 48 27 15 12 11 .43 .44 .43 .42 .39 .40 .53 .66 .63 .56 .61 .52 .36 .28 .90 1.2 .70 2.5 .87 4.6 2.7 3.2 939 610 112 18 4.8 1.8 .75 .50 .39 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) NOVEMBER 12 11 11 23 33 293 116 84 87 96 172 64 38 28 24 21 19 19 17 20 142 63 31 23 55 118 182 84 206 273 10 9 9 18 27 137 109 77 61 180 246 146 75 47 30 20 28 50 82 58 126 64 44 28 55 99 135 79 141 227 2 2 230 38 17 15 103 120 26 7 3 1 1 1 2 3 3 56 11 3 1 13 43 69 19 130 177 .33 .28 .26 .6 .6 .8 .6 .9 .1 .4 .5 .9 .0 .7 .7 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) DECEMBER 116 370 263 106 83 64 53 35 29 25 23 23 28 23 21 19 17 17 16 15 16 16 21 21 18 17 18 18 15 13 12 131 383 329 193 150 116 91 78 69 61 44 30 20 14 13 12 12 11 10 9 8 11 17 23 20 16 13 11 10 11 11 50 430 275 55 34 20 13 7. 5. 4. 2. 1. 1. . . 1. f . . 5 5 1 8 9 5 88 71 63 57 50 43 37 35 49 96 3 99 76 63 50 43 38 36 1785 1710.57 2365 1103.67 1531 911.54 RIO GRANDE DE LOIZA BASIN 269 50057000 RIO GURABO AT GURABO--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 12 13 13 16 15 14 12 12 12 15 14 IS 20 19 15 10 9.7 9.8 13 14 15 17 17 15 19 71 44 42 27 17 17 11 11 11 11 11 12 12 12 12 12 12 25 23 14 15 15 16 16 13 9 7 7 7 7 7 61 56 34 47 45 44 .35 .39 .41 .48 .47 .42 .38 .39 .39 .48 .43 1.4 1.3 .74 .62 .42 .41 .42 .46 .36 .30 .33 .31 .29 .39 15 7.4 3.9 3.4 2.1 2.0 MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) FEBRUARY 15 14 13 13 15 14 15 23 23 36 23 15 11 10 10 13 16 17 16 25 176 93 21 15 1230 301 129 205 ___ 42 39 36 33 30 27 27 34 29 33 10 8 7 7 6 9 15 24 27 27 228 988 28 20 448 337 101 173 ___ ___ 1.8 1.5 1.3 1.2 1.2 1.1 1.1 2.2 1.8 3.5 .63 .32 .21 .18 .18 .32 .68 1.1 1.1 1.8 196 423 1.6 .80 4280 389 36 101 ___ ___ ___ MARCH 82 49 35 28 54 31 29 31 39 36 22 33 38 41 29 19 16 15 14 14 14 13 11 11 13 12 13 13 13 14 12 154 91 54 57 59 37 34 33 37 47 33 33 38 42 24 36 26 15 18 24 33 44 33 20 13 14 19 26 34 25 14 35 12 5.1 4.3 8.6 3.1 2.6 2.9 4.1 4.6 2.0 3.3 3.9 4.7 2.0 1.8 1.1 .61 .67 .89 1.2 1.5 1.0 .59 .45 .46 .69 .90 1.2 .96 .45 TOTAL 577.5 46.14 2507 5450.62 794 112.67 270 DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) 13 14 13 13 13 14 16 17 15 14 13 40 23 12 9. 32 28 14 8. 7. 6. 6. 5. 5. 5. 5. 6. 7. 7. 7. -- 3 5 4 7 0 7 2 2 6 5 3 5 3 - APRIL 9 13 20 33 50 39 24 15 14 16 17 32 25 13 10 39 41 47 40 39 38 37 28 20 14 10 7 5 4 4 ___ MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MAY .32 .49 .73 1.1 1.7 1.5 1.0 .70 .59 .57 .58 3.8 1.7 .43 .25 5.1 3.3 1.9 .93 .78 .69 .59 .43 .27 .19 .15 .13 .11 .09 .08 ___ 5 6 7 7 10 12 10 8 12 14 11 9 8 9 6 25 *5 5 4 12 22 9 6 6 5 5 15 14 41 38 70 .9 .7 .3 .0 .3 .1 .3 .3 .7 .3 .5 .0 .7 .1 .2 .4 4 5 5 5 9 30 33 34 35 36 35 35 33 25 19 48 80 19 8 22 49 19 8 5 6 9 22 24 33 31 83 .07 .08 .10 .09 .35 .94 .90 .75 1.1 1.3 1.1 .85 .73 .63 .34 7.3 3.9 .27 .09 1.0 3.1 .47 .15 .08 .08 .13 .99 .92 3.8 3.4 16 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) JUNE 72 233 629 132 57 46 42 41 22 16 56 50 35 24 334 301 105 49 30 24 27 21 16 13 12 12 12 15 12 9.6 71 165 445 116 61 48 41 46 36 27 51 48 29 18 222 224 115 55 37 24 16 14 14 14 13 13 13 13 14 15 22 110 1120 43 9. 5. 4. 5. 2. 1. 8. 6. 2. 1. 240 207 35 7. 3. 1. 1. • . . - 6 8 6 2 2 2 6 7 8 2 4 0 6 2 77 60 49 43 43 41 51 45 38 -- TOTAL 392.2 30.20 431.8 51.01 2447.6 1842.57 RIO GRANDE DE LOIZA BASIN 50057000 RIO GORABO AT GORABO--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 277 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR 8.7 7.8 7.1 12 24 36 20 15 11 8.8 7.4 31 25 39 41 85 33 20 16 10 9.5 75 31 16 10 8.2 382 131 78 67 73 1338.5 24402.6 JULY 15 12 9 13 24 23 13 15 16 17 13 30 28 45 44 86 43 30 23 20 20 67 44 37 25 16 132 100 75 86 166 —— .37 .26 .17 .45 2.0 2.6 .69 .57 .49 .40 .25 3.6 2.0 4.9 8.9 21 3.9 1.6 .98 .53 .53 16 3.7 1.6 .70 .36 229 37 16 22 38 420.55 24834.79 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) AUGUST MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) 31 57 518 85 34 22 19 19 24 14 10 8.3 7.0 6.3 6.0 6.3 8.5 648 663 97 71 281 71 48 63 39 25 20 18 17 51 51 352 112 32 20 13 14 16 18 17 14 12 11 9 10 12 168 350 99 70 259 98 90 62 50 30 19 17 15 4 8 744 30 3 1 1 759 590 27 14 274 19 12 11 5 2 1 .4 .3 .0 .2 .65 .72 .0 .67 .46 .32 .24 .18 .15 .19 .30 .4 .1 .0 .79 .66 17 2953.4 17 .83 2512.56 SEPTEMBER 14 11 10 9.6 64 1760 201 107 65 42 36 47 31 23 127 2580 569 198 93 286 160 74 107 121 81 90 96 70 116 91 7279.6 18 13 10 9 58 556 121 58 36 23 18 48 27 14 79 1070 929 156 87 162 172 79 87 134 87 77 73 36 92 79 . . 33 3940 74 17 6. 2. 1. 6. 2. . 183 4140 1460 94 22 355 84 16 42 45 19 20 20 6. 30 20 69 40 28 23 5 6 8 2 3 89 8 10642.69 272 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO, PR- -Continued HATER QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DATE OCT 1994 23. .. DEC 02... FEB 1995 22. .. JUN 03. .. JUL 27. .. AUG 03. .. 18. .. SEP 15. .. TIME 0525 0445 0015 0452 1115 0740 2015 2335 DIS- CHARGE, INST. CUBIC FEET PER SECOND 1800 456 230 1080 551 938 822 1350 SEDI- MENT, SUS- PENDED (MG/L) 3168 1640 4801 2733 676 2420 2958 1399 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 15400 2019 2980 7970 1006 6130 6560 5100 SED. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 58 81 49 52 73 53 53 60 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 62 89 59 66 77 60 65 67 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 69 92 69 76 80 82 71 71 DATE OCT 1994 23. .. DEC 02.. . FEB 1995 22.. . JUN 03.. . JUL 27.. . AUG 03.. . 18.. . SEP 15. .. SED. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 79 94 80 85 83 80 84 78 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 90 — 47 86 85 80 87 80 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 96 98 94 96 96 99.7 96 96 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 98.9 99.8 96 98 97 99.7 98 98 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 99.9 99.9 98 98.8 98 99.7 99 99 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99.9 99.9 99 99 99 99.7 99 99.5 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 100 100 99.6 99.4 99.3 99.9 99.6 100 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO, PR—Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT 273 DATE OCT 1994 23... 23.. . 26.. . NOV 30... DEC 02... 03... 04... FEE 1995 18.. . 21.. . 21... JUN 03.. . 03.. . 15.. . JUL 27.. . AUG 18.. . SEP 06... 16. .. 16.. . TIME 0410 0825 1702 1638 0345 1710 0200 1317 1845 2130 0537 1212 1355 1400 2215 0820 0120 1554 STREAM- FLOW, INSTAN- TANEOUS (CFS) 618 926 60 380 535 142 544 18 502 373 1794 512 432 910 5021 1975 3750 1714 SEDI- MENT, SUS- PENDED (MG/L) 626 376 75 326 532 236 365 26 231 692 1380 506 424 224 406 2200 582 306 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 1040 940 12 334 768 90 536 1.3 313 697 6680 699 494 550 5500 11700 5890 1420 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 90 98 98 98 95 99 99 99 99 99 96 99 99 98 99 89 96 92 274 RIO GRANDE DE LOIZA BASIN 50057025 RIO GURABO NEAR GURABO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°15'56", long 65°59'04", at bridge on Highway 941, 1.2 mi (1.9 km) west-northwest from gaging station 50057000, and 1.0 mi (1.6 km) northwest of Gurabo plaza. DRAINAGE AREA.--62.8 mi 1 (162.7 km1 ). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 12. .. DEC 07.. . FEB 1995 08.. . APR 10.. . JUN 08.. . AUG 04. . . DATE OCT 1994 12. . . DEC 07... FEB 1995 08. .. APR 10. .. OUN 08. .. AUG 04... DATE OCT 1994 12. .. DEC 07. . . FEB 1995 08. .. APR 10. .. JUN 08. . . ADG 04. .. DIS- PH OXYGEN, OXYGEN COLI- CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP- HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI NESS CUBIC CON- FIELD TEMPER- TOR- OXYGEN, (PER- ICAL 0.45 FECAL, TOTAL FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH DM-MF (COLS. (MG/L TIME PER ANCE ARD WATER ITY SOLVED SATTJR- LEVEL) (COLS./ PER AS SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) 0735 1050 0810 0735 0715 0715 CALCIUM DIS- SOLVED (MG/L AS CA) 32 -- -- 30 -- 13 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 283 -- -- 270 -- 118 E14 460 7.1 28 E53 298 6.9 27 E14 430 7.1 25 E14 500 7.1 26 E48 241 6.9 29 E96 375 6.6 27 MAGNE- SODIUM SIUM, SODIUM, AD- DIS- DIS- SORP- SOLVBD SOLVED TION (MG/L (MG/L RATIO AS MG) AS NA) 16 38 1 __ -- 16 39 1 __ 4.8 15 0.9 RESIDUE NITRO- TOTAL N1TRO- GEN, AM- AT 105 GEN, MONIA + DEG. C, ORGANIC ORGANIC BUS- TOTAL TOTAL FENDED (MG/L (MG/L (MG/L) AS N) AS N) 20 1.6 1-.6 20 0.80 0.80 15 0.90 0.90 16 1.2 1.2 20 1.5 0.86 56 1.1 2.5 .5 .0 .0 .0 .0 .0 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 5.7 __ __ 5.0 -- 2.0 NITRO- GEN, TOTAL (MO/L AS N) 1.6 0.80 0.90 1.2 1.5 1.1 12 22 7.2 6.8 7.6 30 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 150 100 130 130 94 50 PHOS- PHORUS TOTAL (MG/L AS P) 0.260 0.340 0.600 0.390 0.310 0.500 1.8 23 1.6 20 2.0 24 2.0 24 4.8 62 4.8 60 SULFATE SULFIDE DIS- TOTAL SOLVED (MG/L (MG/L AS S) AS S04) <0.5 27 __ — <0.5 24 __ 3.8 BARIUM, TOTAL ARSENIC RECOV- TOTAL ERABLE (UG/L (UG/L AS AS) AS BA) 2 <100 __ __ 2 <100 — — 23 25 25 17 20 13 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 41 __ -- 47 -- 13 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 60 -- -- 60 -- -- K1800 4300 5600 460 9200 25000 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.20 __ -- 0.20 -- 0.10 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- 21000 150 5900 800 220 140 2600 42000 52 SILICA, DIS- SOLVED (MG/L AS SIO2) 33 -- -- 31 -- 36 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 -- -- E - Estimated K * non-ideal count RIO GRANDE DE LOIZA BASIN 50057025 RIO GURABO NEAR GURABO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 275 DATE OCT 1994 12. .. DEC 07. .. FEB 1995 06. .. APR 10. .. JUN 06. .. AUG 04. .. COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 — — <10 — — IRON, TOTAL RECOV- ERABLE (UG/L AS FE) £20 -- -- 620 -- -- LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) 5 — -- 2 -- -- MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 570 -- -_ 940 -- -- MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 -- — <0.10 — — SELE- NIUM, TOTAL (UG/L AS SE) <1 -- __ <1 -- — SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <1 -- — <1 -- — ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) 20 -- -- 10 -- -- CYANIDE TOTAL PHENOLS (MG/L TOTAL AS CN) (UG/L) •cO.010 <1 __ — •cO.010 <1 — — MBTHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) 0.06 — — 0.07 — — 276 RIO GRANDE DE LOIZA BASIN 50058350 RIO CANAS AT RIO CANAS, PR LOCATION.--Lat 18°17'41«, long 66°02'44", Hydrologic Unit 21010005, at right bank, off road 798, upstream side of bridge on Highway 52, 0.5 mi (0.8 km ) northeast from Escuela Segunda Unidad de Francisco Valdes, and 0.8 mi (1.3 km) north of La Barra. DRAINAGE AREA.--7.53 mi a (19.50 km*). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March 1990 to current year. GAGE.—Water-stage recorder and crest-stage gage. Elevation of gage is 164 ft (50 m), from topographic map. REMARKS.—Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT JAN JUN AUG SEP 1 5.6 1.7 2 2.2 1.5 3 1.8 1.5 4 1.5 1.7 5 1.3 1.5 6 1.3 1.4 7 5.8 1.5 8 56 8.8 9 10 84 10 3.1 62 11 2.2 11 12 1.8 5.2 13 1.7 3.9 14 1.5 3.3 15 1.4 3.3 16 1.4 3.7 17 1.7 2.9 18 4.9 2.6 19 13 2.6 20 25 2.6 21 4.2 3.9 22 42 3.1 23 61 2.3 24 22 2.1 25 5.4 7.5 26 2.7 2.9 27 1.9 13 28 . 1.6 11 29 1.6 27 30 1.6 24 31 1.7 TOTAL 288.9 303.5 MEAN 9.32 10.1 MAX 61 84 MIN 1.3 1.4 AC-FT 573 602 CFSM 1.24 1.34 IN. 1.43 1.50 63 16 46 28 16 6.8 3.4 2.8 2.5 2.2 2.9 2.3 2.5 2.3 1.6 1.5 1.5 1.4 1.6 2.3 2.0 2.0 1.7 1.8 1.6 1.6 7.0 3.4 1.7 1.5 1.5 232.4 7.50 63 1.4 461 1.00 1.15 STATISTICS OF MONTHLY MEAN DATA MEAN 15.6 14.3 MAX 39.4 36.2 (WY) 1991 1993 MIN 4.60 7.18 (WY) 1992 1991 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 12.1 29.9 1993 5.55 1994 FOR 1.5 1.6 2.0 1.7 1.5 1.3 1.3 1.2 1.6 11 2.5 17 11 2.2 5.5 2.2 1.7 1.7 2.4 2.3 1.6 1.6 1.4 1.4 1.3 35 9.4 24 6.2 4.5 3.9 163.5 5.27 35 1.2 324 .70 .81 FOR WATER 10.3 24.5 1992 4.48 1994 3.5 2.9 2.7 2.3 2.4 2.3 2.5 2.8 2.7 2.4 2.2 2.2 2.2 2.2 2.5 5.9 2.3 4.3 16 3.0 . 27 3.8 2.3 1.9 170 62 13 177 ___ —— 526.3 18.8 177 1.9 1040 2.50 2.60 YEARS 1990 10.4 18.8 1995 4.29 1994 25 9.2 14 9.5 5.7 4.8 5.3 4.3 3.7 3.3 3.2 4.1 17 19 6.5 4.9 4.3 4.0 3.9 3.8 3.7 3.3 3.0 2.9 2.8 2.6 2.7 2.8 2.5 2.4 2.3 186.5 6.02 25 2.3 370 .80 .92 - 1995 4.94 6.02 1995 2.48 1994 1994 CALENDAR YEAR 2160. 5. 224 1. 1. 4280 . 10. 8. 2. 1. 0 92 Aug 28 1 Jun 8 2 Jun 8 79 67 8 9 6 2.2 2.1 2.0 1.9 1.9 1.9 2.9 2.0 1.7 4.8 2.4 5.4 2.2 1.9 6.8 12 5.8 4.3 4.0 3.7 3.2 3.1 2.9 2.6 2.4 2.4 2.2 2.2 2.2 2.2 —— 97.3 3.24 12 1.7 193 .43 .48 2.0 2.0 1.8 1.8 3.8 16 37 45 8.5 3.2 2.7 2.6 2.2 2.2 16 3.4 2.4 2.1 2.3 2.8 2.4 1.7 1.6 1.3 26 2.5 2.2 1.7 2.9 1.8 1.5 205.4 6.63 45 1.3 407 .88 1.01 1.4 6.0 3.9 4.8 2.2 1.7 1.3 1.3 44 5.4 3.1 3.0 2.2 2.0 1.8 1.7 1.7 1.5 1.4 2.9 2.1 1.6 1.5 1.4 2.0 1.8 14 6.7 2.2 1.7 —— 128.3 4.28 44 1.3 254 .57 .63 1.6 1.4 3.9 7.0 4.2 7.5 2.4 1.8 1.6 1.4 4.8 3.2 19 6.9 3.1 1.9 1.6 1.4 1.6 2.6 4.8 6.2 3.8 2.3 3.3 2.9 37 37 13 10 4.3 203.5 6.56 37 1.4 404 .87 1.01 3.0 16 83 8.1 4.8 4.6 3.4 2.7 2.7 2.8 2.8 2.6 2.2 5.3 4.8 48 7.9 105 71 17 7.7 21 29 31 16 9.2 7.7 6.0 5.2 10 71 611.5 19.7 105 2.2 1210 2.62 3.02 13 7.2 6.0 5.2 41 467 96 69 56 54 87 177 47 29 62 249 55 20 9.6 21 9.9 7.4 7.4 6.5 5.7 5.7 24 8.1 22 7.4 --- 1675.1 55.8 467 5.2 3320 7.42 8.28 , BY WATER YEAR (WY) 5.26 11.1 1993 3.24 1995 FOR 1995 4622 12 467 1 1 2920 19 1 9170 1 22 28 3 1 9.89 19.5 1992 2.50 1994 WATER YEAR .2 .7 Sep 6 .2 Jan 8 . 5 Jan 2 Sep 6 .01 Sep 6 .1 Jul 18 .68 .83 .0 .6 8.23 20.0 1993 1.78 1994 9.79 24.9 1993 3.40 1990 WATER 11 15 5 467 1 1 3830 20 1 8140 1 20 18 4 2 11.4 19.7 1995 4.36 1990 YEARS 1990 .2 .9 .77 Sep . 1 Jun .2 Jun Oct .55 Oct . 0 Jun .49 .28 .8 .2 15.6 55.8 1995 4.74 1994 - 1995 1993 1994 6 1995 8 1994 8 1994 17 1990 17 1990 21 1994 RIO GRANDE DE LOIZA BASIN 50058350 RIO CANAS AT RIO CANAS, PR—Continued WATER-QUALITY RECORDS PERIOD OP RECORDS.-- Water years 1990 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1994 to September 1995. INSTRUMENTATION.-- Automatic sediment sampler since 1990. REMARKS:-- Sediment samples were collected by a local observer on a weekly basis and during high flow events EXTREMES FOR PERIOD OF DAILY RECORD.— SEDIMENT CONCENTRATION! Maximum daily mean, 3,600 mg/L August 28, 1994; Minimum daily mean, 1 mg/L September 11,1991. SEDIMENT LOADS: Maximum daily mean, 10,800 tons (9,800 tonnes) August 28, 1994; Minimum daily mean, 0.01 ton (0.01 tonne) January 08, 1995. EXTREMES FOR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATION: Maximum daily mean, 3,430 mg/L August 18, 1995; Minimum daily mean, 4 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 9,590 tons (8,700 tonnes) September 06, 1995; Minimum daily mean, 0.01 ton (0.01 tonne) January 08, 1995. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 277 MEAN DISCHARGE DAY (CFS) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 5.6 2.2 1.8 1.5 1.3 1.3 5.8 56 10 3.1 2.2 1.8 1.7 1.5 1.4 1.4 1.7 4.9 13 25 4.2 42 61 22 5.4 2.7 1.9 1.6 1.6 1.6 1.7 MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) OCTOBER 114 42 15 12 11 10 103 2050 135 29 18 11 8 6 5 5 5 47 198 1710 64 814 1080 307 49 21 22 33 48 37 23 NOVEMBER 2.3 .29 .08 .05 .04 .04 7.9 1190 5.1 .25 .11 .06 .04 .03 .02 .02 .02 1.4 22 646 1.3 421 303 41 .78 .15 .11 .14 .21 .16 .10 1.7 1.5 1.5 1.7 1.5 1.4 1.5 8.8 84 62 11 5.2 3.9 3.3 3.3 3.7 2.9 2.6 2.6 2.6 3.9 3.1 2.3 2.1 7.5 2.9 13 11 27 24 15 9 9 10 12 11 11 109 2780 1240 124 22 12 10 9 7 7 7 7 7 22 42 29 24 78 25 189 296 430 335 .07 .04 .04 .05 .05 .04 .04 9.1 2220 1120 4.5 .33 .13 .09 .08 .07 .05 .05 .05 .05 .50 .36 .18 .13 3.6 .20 19 13 72 36 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) DECEMBER 63 16 46 28 16 6.8 3.4 2.8 2.5 2.2 2.9 2.3 2.5 2.3 1.6 1.5 1.5 1.4 1.6 2.3 2.0 2.0 1.7 1.8 1.6 1.6 7.0 3.4 1.7 1.5 1.5 2600 236 1120 407 450 82 24 28 49 80 64 42 27 18 12 8 6 5 5 5 5 5 5 5 5 5 93 116 72 72 70 1370 13 409 37 26 1.6 .22 .21 .32 .48 .50 .26 .19 .11 .05 .03 .02 .02 .02 .03 .03 .03 .02 .02 .02 .02 8.5 1.3 .33 .29 .28 TOTAL 288.9 2643.70 303.5 3499.80 232.4 1869.90 278 RIO GRANDE DE LOIZA BASIN 50058350 RIO CANAS AT RIO CANAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN DISCHARGE (CPS) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1.5 1.6 2.0 1.7 1.5 1.3 1.3 1.2 1.6 11 2.5 17 11 2.2 5.5 2.2 1.7 1.7 2.4 2.3 1.6 1.6 1.4 1.4 1.3 35 9.4 24 6.2 4.5 3.9 65 60 55 49 25 10 4 4 4 156 124 243 208 84 70 64 58 54 62 76 89 81 71 62 55 488 105 325 50 35 28 .27 .25 .29 .22 .10 .03 .02 .01 .02 17 .92 33 29 .49 1.1 .38 .27 .25 .40 .46 .39 .35 .26 .23 .20 101 5.9 36 .84 .42 .30 3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 5 2 4 16 3 27 3 2 1 170 62 13 177 _ - - MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) FEBRUARY .5 .9 .7 .3 .4 .3 .5 .8 .7 .4 .2 .2 .2 .2 .5 .9 .3 .3 .0 .8 .3 .9 __ --— 23 26 31 34 28 22 17 13 10 8 6 6 7 7 8 49 22 40 3340 2630 468 82 45 42 2460 1270 303 2060 ___ ___ .22 .20 .22 .21 .18 .14 .11 .10 .07 .05 .04 .04 .04 .04 .05 2.5 .14 .94 708 35 75 .97 .29 .22 6710 888 14 4490 ___ ___ ___ 25 9. 14 9. 5. 4. 5. 4. 3. 3. 3. 4. 17 19 6. 4. 4. 4. 3. 3. 3. 3. 3. 2. 2. 2. 2. 2. 2. 2. 2. MARCH 2 5 7 8 3 3 7 3 2 1 5 9 3 0 9 8 7 3 0 9 8 6 7 8 5 4 3 318 207 274 245 119 85 61 45 42 43 43 41 268 294 157 93 55 33 21 13 9 6 6 8 11 16 21 30 39 25 11 24 5.4 25 5.8 1.8 1.1 .85 .52 .42 .38 .37 .45 29 20 2.8 1.3 .65 .35 .22 .14 .09 .05 .05 .06 .09 .11 .16 .22 .26 .16 .07 TOTAL 163.5 230.37 526.3 12926.77 186.5 121.87 DAY 1 2 3 4 5 6 7 e 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 RIO GRANDE DE LOIZA BASIN 50058350 RIO CANAS AT RIO CANAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 279 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) APRIL 2.2 2.1 2.0 1.9 1.9 1.9 2.9 2.0 1.7 4.8 2.4 5.4 ' 2.2 1.9 6.8 12 5.8 4.3 4.0 3.7 3.2 3.1 2.9 2.6 2.4 2.4 2.2 2.2 2.2 2.2 6 6 7 9 11 14 19 24 IB 65 87 70 37 16 98 164 58 59 56 42 31 24 24 26 29 31 29 28 27 27 .03 .03 .04 .04 .05 .07 .14 .13 .08 2.7 .58 1.1 .22 .09 12 11 .92 .69 .61 .42 .27 .20 .19 .19 .19 .20 .17 .17 .16 .16 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MAY 2.0 2.0 1.8 1.8 3.8 16 37 45 8.5 3.2 2.7 2.6 2.2 2.2 16 3.4 2.4 2.1 2.3 2.8 2.4 1.7 1.6 1.3 26 2.5 2.2 1.7 2.9 1.8 1.5 27 27 27 23 34 250 1280 1280 96 27 24 28 31 22 222 37 44 57 44 34 33 35 36 37 1310 74 37 32 31 31 29 .15 .14 .13 .11 .57 48 521 512 3.4 .23 .17 .20 .18 .13 36 .33 .27 .32 .27 .26 .21 .16 .16 .13 980 .51 .22 .15 .24 .15 .12 MEAN DISCHARGE (CPS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) JUNE 1.4 6.0 3.9 4.8 2.2 1.7 1.3 1.3 44 5.4 3.1 3.0 2.2 2.0 1.8 1.7 1.7 1.5 1.4 2.9 2.1 1.6 1.5 1.4 2.0 1.8 14 6.7 2.2 1.7 17 69 16 40 12 9 7 7 629 100 47 30 19 13 17 29 43 30 19 36 43 18 11 7 14 14 236 97 42 31 .06 1.5 .16 1.7 .08 .04 .02 .02 561 1.7 .40 .25 .11 .07 .08 .13 .19 .12 .07 .47 .24 .08 .04 .03 .21 .07 35 2.9 .25 .14 TOTAL 97.3 32.84 205.4 2105.91 128.3 607.13 280 RIO GRANDE DE LOIZA BASIN 50058350 RIO CANAS AT RIO CANAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- DISCHARGE TRATION DAY (CPS) (MG/L) JULY 1 1.6 22 2 1.4 14 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR 3. 7. 4. 7. 2. 1. 1. 1. 4. 3. 19 6. 3. 1. 1. 1. 1. 2. 4. 6. 3. 2. 3. 2. 37 37 13 10 4. 203. 4622. 9 0 2 5 4 8 6 4 8 2 9 1 9 6 4 6 6 8 2 8 3 3 9 3 5 2 48 68 20 116 26 24 21 18 44 61 294 67 23 25 21 21 21 21 38 55 47 29 23 19 564 886 142 179 143 —— SEDIMENT DISCHARGE (TONS/DAY) .10 .05 2. 1. 9. 1. 62 1. • , . . 1. , • 112 305 7. 10 1. 519. 47881. 2 4 24 4 17 12 09 07 1 54 8 21 13 09 08 09 15 72 8 50 19 20 15 1 7 39 08 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) AUGUST 3.0 26 .22 16 223 25 83 8 4 4 3 2 2 2 2 2 2 5 4 48 7 105 71 17 7 21 29 31 16 9 7 6 5 10 71 611 .1 .8 .6 .4 .7 .7 .8 .8 .6 .2 .3 .8 .9 .7 .2 .7 .0 .2 .5 1720 84 36 37 12 9 10 11 11 11 10 38 41 1790 65 3430 1130 151 29 273 441 461 180 78 38 21 20 136 2740 —— 1540 2 1 939 1 1760 266 7 29 54 61 7 2 11 2120 6832 .0 .48 .55 .11 .06 .07 .08 .08 .07 .06 .4 .64 .5 .8 .63 .9 .0 .79 .34 .28 .06 MEAN MEAN CONCEN- DISCHARGE TRATION (CPS) (MG/L) SEPTEMBER 13 465 7.2 92 6. 5. 41 467 96 69 56 54 87 177 47 29 62 249 55 20 9. 21 9. 7. 7. 6. 5. 5. 24 8. 22 7. -- 1675. 0 2 6 9 4 4 5 7 7 1 4 - 1 73 56 666 2690 71 35 35 35 1650 1900 159 51 1100 2680 784 59 14 284 59 22 23 24 25 23 317 46 284 79 --- —— SEDIMENT DISCHARGE (TONS/DAY) 24 1.8 1. 205 9590 19 6. 5. 5. 853 2820 24 4. 487 2170 130 3. . 48 1. • 48 1. 38 1. - 16491. 2 79 5 2 1 0 8 37 7 44 46 43 39 36 2 6— 34 RIO GRANDE DE LOIZA BASIN 50058350 RIO CANAS AT CANAS, PR—Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OP SUSPENDED SEDIMENT 281 DATE SEDI- MENT, STREAM- SEDI- DIS- PLOW, KENT, CHARGE, INSTAN- SUS- SUS- TIME TANEOUS FENDED FENDED SED. SUSP. SIEVE DIAM. PERCENT FINER THAN (CPS) (MG/L) (T/DAY) .062 MM OCT 1994 OB. .. 19. .. 20... 22... NOV 10... 09... DEC 01... 14. .. JAN 1995 26... FEE 25. .. 26. .. 28. .. MAR 01... MAY 08. .. 17. .. •TON 09. .. JtTL 06. .. 27. .. 26... ADG IB... SEP 06... 16... 1550 1735 0235 2330 1317 1047 1302 1705 1135 1932 1507 1817 1736 1837 1745 1702 1543 1545 1827 1522 1416 0042 341 11 218 139 694 366 461 2.7 17 171 1520 183 17 199 2 442 27 79 191 187 232 212 21000 475 28000 3460 12800 5180 9820 16 183 4600 11070 1610 425 7820 69 13700 1640 1360 11400 5030 1400 3830 19300 14 16500 1300 24000 5120 12200 0.12 8.4 2120 45400 795 19 4200 0.37 16300 119 290 5880 2540 877 2190 97 99 96 97 93 84 97 79 98 94 87 92 98 97 99 84 99 99 99 98 88 92 282 RIO GRANDE DE LOIZA BASIN 50058350 RIO CANAS AT CANAS, PR--Continued HATER QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OP SUSPENDED SEDIMENT DATE OCT 1994 08. .. NOV 09. .. 09... DEC 03. .. 03. .. FEB 1995 19. .. 28... HAY 07. .. 25. . . OUN 09... 09. .. AGO 16... 16. .. 31. .. 31... DATE OCT 1994 08... NOV 09. . . 09... DEC 03... 03... PEB 1995 19.. . 28.. . MAY 07. .. 25.. . JUN 09... 09.. . AGO 16. .. 16.. . 31.. . 31.. . TIME 1630 1122 1720 1607 1650 2012 1422 1707 1237 1807 1827 1337 1800 1537 1607 SED. SUSP. PALL DIAM. PERCENT FINER THAN .016 MM 76 48 79 70 81 64 52 75. 64 66 68 75 78 47 57 DIS- CHARGE, INST. CUBIC FEET PER SECOND 200 647 75 243 151 212 1180 207 298 398 256 199 123 858 852 SED. SUSP. PALL DIAM. PERCENT FINER THAN .031 MM 87 64 87 80 88 82 64 89 80 74 82 84 86 60 71 SEDI- MENT, SUS- PENDED (MG/L) 16960 16200 7620 6540 5365 34000 15500 22300 32160 15700 23500 15200 2710 17300 20200 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 98 81 98 94 97 96 79 98 93 90 95 97 98 75 86 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 9160 28300 1540 4290 2190 19500 4940 12500 25900 16900 16200 8170 900 40100 46500 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 99.6 94 99 98 99 99.6 91 99.7 99 98 99 99 99.6 91 95 SED. SUSP. PALL DIAM. PERCENT FINER THAN .002 MM 40 25 45 38 48 25 25 33 26 34 31 36 46 28 25 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 99.9 98 99.8 99.6 99.8 99.9 96 99.9 99.8 99 99.8 99.9 99.8 96 99 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 52 31 52 46 56 34 33 44 34 38 38 48 57 35 34 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99.9 99 99.9 99.7 99.9 99.9 98 99.9 99.9 99.6 99.9 99.9 99.9 99 99.7 SBD. SUSP. PALL DIAM. PERCENT FINER THAN .008 MM 62 35 65 60 71 46 41 57 46 48 51 61 65 37 43 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 99.9 99.8 99.9 99.9 99.9 99.9 99 99.9 99.9 99.7 99.9 99.9 99.9 99.6 99.9 RIO GRANDE DE LOIZA BASIN 50058350 RIO CANAS AT CANAS, PR—Continued HATER QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBDTION OF SUSPENDED SEDIMENT 283 DATE SEP 1995 07. .. 11. . . 15. .. TIME 0736 1422 2322 DIS- CHARGE, INST. CUBIC FEET PER SECOND 2850 378 239 SEDI- MENT, SUS- PENDED (MO/L) 12900 13800 14600 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 99300 14100 9420 SED. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 30 33 33 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 33 36 38 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 44 42 46 SEP 1995 07.. . 11.. . 15.. . SED. SUSP. FALL DIAM. PERCENT FINER THAN 016 MM 56 54 62 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 66 68 78 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 78 86 93 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 89 95 98 SED. SED. SED. SUSP. SUSP. SUSP. SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. PERCENT PERCENT PERCENT FINER FINER FINER THAN THAN THAN .250 MM .500 MM 1.00 MM 93 99 99.8 95 99.7 99.9 98 99.9 99.9 284 RIO GRANDE DE LOIZA BASIN 50059000 LAGO LOIZA AT DAHSITE NEAR TRUJILLO ALTO, PR LOCATION.--Lat 18°19'49", long 66°01'00", Hydrologic Unit 21010005, at pump site at damsite, and 1.9 mi (3.1 km) south of Trujillo Alto plaza. DRANAIGE AREA.--208 mi 1 (539 km 1 ). ELEVATION RECORDS PERIOD OF RECORD.—December 1967 to current year. Prior to October 1994, published as Lago Loiza at Damsite. GAGE.—Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lake is formed by Loiza Dam, a concrete structure completed in 1954. Useable capacity of impoundment is 30,000 acre-ft (37.0 hm3 ) . Out flow from lake is controlled by five slide gates in powerplant and pump intake structure, four sluice gates, and concrete spillway with eight radial gates. Lake is used for municipal water supply and intermittent power generation. Gage-height satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 147.42 ft (44.93 m), Sept. 16, 1969; minimum elevation, 108.52 ft (33.08 m), July 18, 1994. EXTREMES FOR CURRENT YEAR.--Maximum elevation 135.10 ft (41.18 m) , Aug. 3; minimum elevation, 115.83 ft (35.30 m). May 30. 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 98.4 5,000 128.6 18,000 111.5 8,900 137.8 26,000 120.4 13,000 147.6 35,000 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES DAY OCT NOV DEC JAN FEE MAR APR MAY JUN JUL AUG SEP 1 132.88 134.09 134.65 133.11 129.98 134.74 132.18 A 117.39 129.75 134.36 133.97 2 132.70 134.02 134.15 132.96 129.76 134.86 131.91 123.58 121.09 129.48 134.52 133.89 3 132.54 133.94 133.97 132.82 129.54 134.62 131.67 123.12 127.33 129.23 134.18 133.81 4 132.36 133.94 134.65 132.70 129.32 134.66 131.40 122.63 128.35 128.99 134.54 133.65 5 132.19 134.00 134.33 132.54 129.04 134.92 131.18 122.26 128.59 128.85 134.60 125.67 6 131.98 134.70 134.55 132.37 128.80 134.92 130.93 121.98 128.63 128.79 134.60 128.99 7 131.84 134.44 134.69 132.21 A 134.62 130.71 121.92 128.61 128.68 134.60 132.87 8 132.42 134.47 134.77 132.00 A 134.70 130.50 122.22 128.57 128.43 134.54 134.69 9 132.40 134.63 134.79 131.82 A 134.80 130.26 122.36 128.58 128.21 134.54 134.49 10 132.26 134.77 134.78 131.78 128.04 134.86 130.01 122.21 128.43 127.92 134.46 134.79 11 132.06 134.53 134.78 131.64 127.88 134.84 129.71 121.86 128.44 127.74 134.32 134.49 12 131.84 134.71 134.80 131.90 127.66 134.87 129.70 121.49 128.38 127.60 134.18 134.41 13 131.66 134.81 134.80 131.88 127.42 134.61 129.58 121.09 128.27 127.74 134.02 134.69 14 131.38 134.81 134.78 131.74 127.16 134.83 129.35 120.84 128.09 128.06 133.84 134.79 15 131.19 134.79 134.82 131.66 126.90 134.85 129.26 120.52 129.70 128.10 133.69 122.13 16 130.96 134.77 134.80 131.49 126.68 134.81 129.22 120.60 131.10 128.66 133.65 131.63 17 130.77 134.69 134.72 131.27 126.48 134.71 129.11 120.46 131.50 128.68 133.55 134.51 18 131.06 134.63 134.63 131.07 126.33 134.61 128.86 120.10 131.49 128.64 133.93 134.58 19 131.30 134.59 134.54 130.90 126.24 134.49 128.60 119.70 131.37 128.56 134.33 134.32 20 131.96 134.59 134.46 130.68 126.14 134.37 128.28 A 131.31 128.40 134.51 134.82 21 132.00 134.65 134.35 130.46 128.30 134.22 127.96 A 131.30 128.24 134.51 134.30 22 132.42 134.60 134.23 130.25 129.16 134.07 127.63 A 131.19 128.84 134.31 134.34 23 134.40 134.54 134.17 129.99 129.28 133.91 127.28 118.51 130.99 128.86 134.79 134.56 24 134.80 134.47 134.08 129.74 129.26 133.75 126.92 118.04 130.77 128.80 134.55 134.50 25 134.74 134.64 133.98 129.52 134.18 133.57 126.56 117.70 130.58 128.70 134.65 134.48 26 27 28 29 30 31 MAX 134.84 134.81 134.82 133.11 —— 134.92 —— —— 131.50 134.70 134.79 134.82 MIN 130.77 133.94 133.26 129.52 —— 132.37 —— —— 117.39 127.60 133.55 122.13 CAL YR 1994 MAX 134.84 MIN 108.62 A No gage-height record 134.66 134.84 134.12 134.14 134.14 134.11 134.18 134.30 134.54 134.57 134.77 ___ 133.86 133.82 133.72 133.58 133.41 133.26 130.04 130.32 130.50 130.48 130.36 130.19 134.48 134.52 134.34 ___ 133.39 133.21 133.03 132.79 132.58 132.37 126.19 125.78 A A A___ 117.19 116.62 116.18 116.01 116.13 117.07 130.57 130.60 130.54 130.29 130.03 128.48 132.84 133.68 134.20 134.62 134.70 134.23 134.35 134.37 134.41 134.47 133.97 134.67 134.77 134.47 134.79 134.55 ___ 285 RIO GRANDE DE LOIZA BASIN 50059000 LAGO LOIZA AT DAMSITE NEAR TRUJILLO ALTO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°19'49", long 66°01'00", at pumphouse at damsite, and 1.9 mi (3.1 km) south of Tru- jillo Alto plaza. DRAINAGE AREA.--208 mi 1 (539 km1 ). PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 13.. . DEC 15.. . FEB 1995 08... APR 10.. . JUN 09.. . AUG 04.. . TIME 0915 1045 1110 0940 0930 0820 SPE- CIFIC CON- DUCT- ANCE (US/CM) 204 250 373 315 307 290 PH WATER WHOLE FIELD (STAND- ARD UNITS) 6.6 6.6 6.7 6.7 6.6 6.5 TEMPER- ATURE WATER (DEG C) 27.0 27.0 26.5 27.0 27.0 28.0 OXYGEN, DIS- SOLVED (MG/L) 0.3 0.6 0.4 1.4 1.5 1.8 OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 4 7 5 17 18 23 OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 25 26 15 20 17 15 COLI- FORM, FECAL, 0.45 UM-MF (COLS. / 100 ML) K34 K23 K16 Kll K240 310 STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 470 K13 K13 40 580 200 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 59 67 100 98 85 79 SULFIDE TOTAL (MG/L AS S) <0.5 -- — <0.5 -- -- DATE OCT 1994 13. .. DEC 15. .. FEB 1995 08. .. APR 10. .. JUN 09. . . AUG 04. .. RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 30 8 7 7 32 12 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 1.0 0.70 0.80 1.1 0.90 1.3 PHOS- PHORUS TOTAL (MG/L AS P) 0.160 0.140 0.100 0,110 0.100 0.120 BORON, COPPER, IRON, TOTAL TOTAL TOTAL RECOV- RECOV- RECOV- ERABLE ERABLB ERABLE (UG/L (UG/L (UG/L AS B) AS CU) AS FE) 30 <10 1600 __ __ 40 20 150 __ __ MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS HN) 610 -- -- 350 -- — ZINC, TOTAL RECOV- CYANIDE ERABLE TOTAL PHENOLS (UG/L (MG/L TOTAL AS ZN) AS CN) (UG/L) 10 10 •cO.010 <0.010 <1 METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) 0.04 0.07 non-ideal count 286 RIO GRANDE DE LOIZA BASIN 50059050 RIO GRANDE DE LOIZA BELOW DAHSITE, PR LOCATION.--Lat 18°20'33" , long 66°00'20", Hydrologic Unit 21010005, on left bank of Highway 175, 1.1 mi (1.8 km) downstream of Lago Loiza Dam. DRAINAGE AREA.--209 mi 2 (541 km 2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1986 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 32 ft (10 m), from topographic map. REMARKS.--Records poor. Flow regulated by Lago Loiza Dam. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY NOV MAY JUN 1 el. 7 6.4 2 el. 7 2.1 3 el. 8 1.4 4 e2.0 1.7 5 el. 7 1.4 6 e2.2 146 7 el. 9 325 8 e2.7 208 9 el. 8 239 10 e2.2 166 11 el. 9 312 12 62.4 3.2 13 62.0 1.8 14 62.3 1.8 15 e2.4 1.7 16 62.4 2.3 17 62.8 1.8 18 3.0 1.8 19 2.9 2.4 20 7.2 2.6 21 2.9 69 22 2.0 32 23 674 1.7 24 1500 1.8 25 504 11 26 245 33 27 1.7 433 28 229 3.1 29 1.8 208 30 1.5 235 31 1.3 —— TOTAL 3212.2 2456.0 MEAN 104 81.9 MAX 1500 433 MIN 1.3 1.4 AC-FT 6370 4870 CFSM .50 .39 IN. .57 .44 238 884 481 2.1 193 3.3 2.5 2.6 2.5 2.7 2.9 2.6 2.7 2.6 2.6 2.5 2. 2. 2. 2. 2. 2. 2.0 2.0 2.0 2.0 2.2 2.6 2.9 2.3 2.1 1862.1 60.1 884 2.0 3690 .29 .33 2.0 2.1 2.0 2.1 2.0 1.9 2.0 2.0 2.0 2.9 4.0 5.0 3.4 3.2 2.8 3.0 2.9 2.9 2.7 2.6 2.4 2.4 2.4 2.3 2.2 2.9 2.9 2.1 1.6 1.4 1.2 77.3 2.49 5.0 1.2 153 .01 .01 STATISTICS OF MONTHLY MEAN DATA FOR WATER MEAN 249 572 MAX 842 2732 (WY) 1991 1988 MIN 44.7 81.9 (WY) 1992 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 414 2603 1988 17.2 1994 FOR 152 733 1992 2.49 1995 1.0 1.0 1.0 1.1 1.0 .97 1.0 1.1 .97 .90 1.0 .98 .94 .83 .93 1.0 .94 .89 9.0 2.8 2.0 1.7 6.2 2.2 22 727 192 532 ___ ___ --- 1514.45 54.1 727 .83 3000 .26 .27 YEARS 1987 78.2 242 1989 4.52 1990 20 2.3 118 2.2 1.5 1.4 113 1.4 1.1 1.1 1.0 1.1 124 2.1 1.4 1.3 1.1 .92 .77 .54 .69 .69 .78 .65 .67 .78 .66 .91 1.8 .95 .82 405.63 13.1 124 .54 805 .06 .07 - 1995 52.1 299 1989 6.45 1990 1994 CALENDAR YEAR 12914. 35. 3260 25620 2. 11 2. 1. 87 4 Sep 20 48 Aug 13 49 Aug 11 17 30 6 4 .84 .95 1.1 1.1 1.2 1.1 1.1 .92 .92 1.2 1.3 .92 .78 .93 1.1 1.8 1.4 1.3 1.5 1.5 1.5 1.5 1.5 1.4 1.3 1.3 1.5 1.1 1.0 .97 —— 36.03 1.20 1.8 .78 71 .01 .01 .97 1.0 1.2 .80 2.2 1.7 1.1 .90 .94 .70 .57 .48 .42 .49 .66 1.2 .84 .59 .58 1.1 4.2 .75 .60 .70 .88 1.3 1.4 .97 .86 .97 .98 32.05 1.03 4.2 .42 64 .00 .01 1.2 2.5 1.4 .91 .88 .98 .96 .97 .88 2.4 1.7 .94 .70 .81 .83 1.2 1.3 .78 .78 .81 .86 .62 .53 .49 .50 .64 1.2 4.1 20 19 —— 70.87 2.36 20 .49 141 .01 .01 13 1.5 1.2 2.0 1.3 3.4 1.2 1.0 1.0 1.0 1.0 .87 .72 .97 1.3 .97 .86 1.0 1.2 1.0 1.8 5.1 1.8 1.1 .98 .99 6.2 234 3.3 .71 140 432.47 14.0 234 .71 858 .07 .08 6166 62.4 e712 6408 6215 el!7 623 63.2 62.2 1.8 1.1 1.5 1.6 1.6 1.7 1.6 1.7 1200 3270 6496 6144 529 2.0 201 238 212 1.1 1.1 1.1 1.6 367 8325.3 269 3270 1.1 16510 1.28 1.48 2.6 1.7 1.5 2.9 3230 5090 3.3 2.2 230 3.9 276 335 3.3 3.6 4190 4210 881 626 366 268 539 189 189 228 82 122 185 193 220 206—— 21880.0 729 5090 1.5 43400 3.49 3.89 , BY WATER YEAR (WY) 34.7 112 1987 1.20 1995 FOR 1995 40304 110 5090 38500 26 79940 7 228 1 103 367 1992 1.03 1995 WATER YEAR .40 Sep 6 .42 May 13 .61 May 9 Oct 24 .16 Oct 24 .53 .17 .8 .83 178 784 1987 1.96 1994 165 672 1993 1.62 1994 WATER 212 652 37 51200 124000 39 153700 1 13 377 8 2 173 718 1988 2.21 1994 YEARS 1987 .8 Nov .42 May .49 Aug Nov . 57 Nov .01 .79 .6 .2 407 1612 1989 29.7 1990 - 1995 1988 1994 27 1987 13 1995 11 1994 27 1987 27 1987 e Estimated RIO GRANDE DE LOIZA BASIN 50059050 RIO GRANDE DE LOIZA BELOW DAM SITE LOIZA, PR—Continued WATER-QUALITY RECORDS PERIOD OP RECORD.-- Water years 1987 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: December 1986 to September 1995. INSTRUMENTATION.— Automatic sediment sanpler, since 1987. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 946 mg/L January 05, 1992; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 98,600 tons (89,400 tonnes) January 06 , 1992; Minimum daily mean, <0.01 tons (<0.01 tonne) several days. EXTREMES FOR CURRENT YEAR 1995.-- SEDIMBNT CONCENTRATION: Maximum daily mean, 944 mg/L September 6, 1995; minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 25,800 tons (23,400 tonnes) September 6, 1995; minimum daily <0.01 tons (<0.01 tonne) several days. 257 SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) OCTOBER 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 el. 7 el. 7 el. 8 e2.0 el. 7 e2.2 el. 9 e2.7 el. 8 e2.2 el. 9 e2.4 e2.0 «2.3 e2.4 e2.4 e2.8 3.0 2.9 7.2 2.9 2.0 674 1500 504 245 1.7 229 1.8 1.5 1.3 4 .02 4 5 5 6 6 7 7 8 8 9 10 10 11 12 13 14 .02 .02 .03 .03 .03 .04 .05 .04 .05 .05 .06 .06 .07 .08 .09 .10 15 .12 16 .13 26 .51 20 .16 15 .08 49 361 143 3760 77 271 47 131 10 .05 30 114 15 .07 13 .05 11 .04 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) NOVEMBER 6.4 2.1 1.4 1.7 1.4 146 325 208 239 166 312 3.2 1.8 1.8 1.7 2.3 1.8 1.8 2.4 2.6 69 32 1.7 1.8 11 33 433 3.1 208 235 18 15 13 12 12 33 56 45 50 48 63 17 13 12 12 14 13 13 12 12 18 26 13 12 22 20 43 16 34 39 72 149 108 124 77 163 42 6 1 17 211 112 132 .63 .09 .05 .06 .05 .17 .06 .06 .06 .10 .06 .06 .08 .09 .4 .06 .06 .4 .14 238 884 481 2 193 3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 DECEMBER .1 .3 .5 .6 .5 .7 .9 .6 .7 .6 .6 .5 .0 .0 .0 .0 .2 .6 .9 .3 .1 41 86 38 13 37 17 15 15 15 15 15 15 15 15 15 15 15 14 14 14 14 14 14 14 14 14 14 14 16 17 16 128 468 240 .07 104 .16 .10 .11 .10 .11 .11 .11 .11 .10 .10 .10 .10 .09 .09 .09 .09 .09 .08 .08 .08 .08 .09 .10 .14 .10 .09 TOTAL 3212.2 4639.05 2456.0 1216.68 1862.1 942.67 e Estimated 288 RIO GRANDE OB LOIZA BASIN 50059050 RIO GRANDE OB LOIZA BELOW DAM SITE LOIZA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE THAT ION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 € 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 2.0 2.1 2.0 2.1 2.0 1.9 2.0 2.0 2.0 2.9 4.0 5.0 3.4 3.2 2.8 3.0 2.9 2.9 2.7 2.6 2.4 2.4 2.4 2.3 2.2 2.9 2.9 2.1 1.6 1.4 1.2 16 16 15 15 15 14 14 14 13 14 19 20 18 17 17 16 16 16 15 15 14 14 14 13 13 13 12 12 11 9 8 .09 .09 .08 .08 .08 .08 .08 .07 .07 .12 .21 .26 .16 .15 .12 .13 .13 .12 .11 .11 .09 .09 .09 .08 .08 .10 .10 .07 .05 .03 .02 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) FEBRUARY 1.0 1.0 1.0 1.1 1.0 .97 1.0 1.1 .97 .90 1.0 .98 .94 .83 .93 1.0 .94 .89 9.0 2.8 2.0 1.7 6.2 2.2 22 727 192 532 ___ 7 6 5 4 4 3 3 2 2 2 2 2 2 1 1 1 1 1 111 366 169 80 39 15 20 50 46 267 ___ —— .02 .02 .01 .01 .01 .01 .01 .01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 11 3.1 .86 .38 .61 .09 20 362 107 595 ___ ___ MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MARCH 20 2.3 118 2.2 1.5 1.4 113 1.4 1.1 1.1 1.0 1.1 124 2.1 1.4 1.3 1.1 .92 .77 .54 .69 .69 .78 .65 .67 .78 .66 .91 1.8 .95 .82 148 15 34 20 17 14 35 12 12 12 13 13 36 14 11 8 7 6 5 4 3 2 2 2 2 1 1 1 8 10 8 5.5 .10 61 .12 .07 .05 62 .05 .04 .04 .03 .04 65 .08 .04 .03 .02 .01 .01 <.01 .01 .01 .01 .01 .01 .01 .01 .01 .06 .03 .02 TOTAL 77.3 —— 3.14 1514.45 —— 1100.14 405.63 —— 194.35 o on RIO GRANDE DE LOIZA BASIN ^ ° 50059050 RIO GRANDE DE LOIZA BELOW DAM SITE LOIZA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 .84 .95 1.1 1.1 1.2 1.1 1.1 .92 .92 1.2 1.3 .92 .78 .93 1.1 1.8 1.4 1.3 1.5 1.5 1.5 1.5 1.5 1.4 1.3 1.3 1.5 1.1 1.0 .97 ___ APRIL 6 5 4 3 3 3 3 4 4 4 4 3 3 2 2 1 1 1 1 2 2 3 3 4 5 5 6 6 7 7 ___ MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MAY .02 .01 .01 .01 .01 .01 .01 .01 .01 .01 .01 .01 .01 .01 <.01 .01 <.01 •c.Ol •c.Ol .01 .01 .01 .01 .02 .02 .02 .02 .02 .02 .02 ___ .97 1.0 1.2 .80 2.2 1.7 1.1 .90 .94 .70 .57 .48 .42 .49 .66 1.2 .84 .59 .58 1.1 4.2 .75 .60 .70 .88 1.3 1.4 .97 .86 .97 .98 8 9 9 10 12 12 10 8 6 5 4 3 3 3 3 2 2 2 2 2 12 8 7 6 5 5 5 5 5 6 6 .02 .02 .03 .02 .09 .06 .03 .02 .02 .01 .01 <.01 <.01 <.01 <.01 .01 -c.Ol <.01 <.01 .01 .15 .02 .01 .01 .01 .02 .02 .01 .01 .02 .02 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) JUNE 1.2 2.5 1.4 .91 .88 .98 .96 .97 .88 2.4 1.7 .94 .70 .81 .83 1.2 1.3 .78 .78 .81 .86 .62 .53 .49 .50 .64 1.2 4.1 20 19 ___ 6 10 15 20 26 34 42 37 31 27 23 19 16 14 12 10 8 7 6 5 5 6 6 7 8 8 9 15 23 27 ___ .02 .07 .06 .05 .06 .09 .11 .10 .08 .17 .11 .05 .03 .03 .03 .03 .03 .02 .01 .01 .01 .01 .01 .01 .01 .02 .03 .23 2.0 2.6 ___ TOTAL 36.03 --- 0.34 32.05 --- 0.65 70.87 --- 6.09 290 ^^V RIO GRANDE DE LOIZA BASIN 50059050 RIO GRANDE DE LOIZA BELOW DAM SITE LOIZA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) JULY 13 1 1 2 1 3 1 1 1 1 1 1 1 1 1 1 5 1 1 6 234 3 140 TOTAL 432 YEAR e 40304 .5 .2 .0 .3 .4 .2 .0 .0 .0 .0 .87 .72 .97 .3 .97 .86 .0 .2 .0 .8 .1 .8 .1 .98 .99 .2 .3 .71 .47 .40 24 11 10 9 9 17 14 14 13 12 12 11 11 10 10 9 9 8 8 7 8 21 33 69 146 246 113 71 14 8 34 —— 1.6 .05 .03 .05 .03 .17 .05 .04 .03 .03 .03 .03 .02 .03 .03 .02 .02 .02 .03 .02 .06 .35 .16 .20 .38 .67 1.5 129 .28 .02 79 213.95 49160.28 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) AUGUST e!66 e2. e712 e408 e215 el!7 e23 e3. e2. 1. 1. 1. 1. 1. 1. 1. 1. 1200 3270 e496 e!44 529 2. 201 238 212 1. 1. 1. 1. 367 8325. 4 2 2 8 1 5 6 6 7 6 7 0 1 1 1 6 3 57 22 117 146 105 75 47 27 15 9 9 9 9 8 8 8 8 27 192 103 56 80 14 37 44 36 10 9 9 8 56 —— e64 e. e361 e!70 e62 e24 e3. e. e. 476 1800 e257 e56 241 . 82 136 117 . 209 4059. 14 1 24 09 05 03 03 04 04 04 03 04 08 03 03 03 04 08 MEAN DISCHARGE (CFS) ! 2. 1. 1. 2. 3230 5090 3. 2. 230 3. 276 335 3. 3. 4190 4210 881 626 366 268 539 189 189 228 82 122 185 193 220 206— 21880. 6 7 5 9 3 2 9 3 6 - 0 Estimated MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) SEPTEMBER 32 .23 28 .12 24 .09 21 .16 94 1540 944 25800 465 4.5 171 1.1 56 104 20 .25 59 148 65 193 96 .85 87 .84 124 2010 177 4680 99 509 73 260 111 215 58 132 83 291 46 105 45 105 46 126 26 54 38 59 46 104 46 102 50 124 41 115 36784.14 RIO GRANDE DE LOIZA BASIN 50059050 RIO GRANDE DE LOIZA BELOW DAMSITE LOIZA, PR—Continued HATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT 291 DATE FEE 1995 28.. . MAR 01... JUL 26. .. AUG 18... 19... SEP 07... 14... 15... 15... 16... 19... 20. .. TIME 1730 1315 1230 2213 1402 1215 1300 1611 1841 0536 1150 1011 STREAM- FLOW, INSTAN- TANEOUS (CFS) 2040 2.00 1.20 18400 8780 2.90 2.60 20000 21900 15400 7.70 5.10 SEDI- MENT, SUS- PENDED (MO/L) 174 88 305 89 185 380 89 130 268 574 144 30 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 958 0.48 1.0 4420 4390 3.0 0.62 7020 15800 23900 3.0 0.41 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 98 82 95 92 94 99.5 95 95 95 99 99 75 292 RIO GRANDE DE LOIZA BASIN 50059100 RIO GRANDE DE LOIZA BELOW TRUJILLO ALTO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°21'35», long 660 00'15« r 100 ft (30 m) downstream of Highway 181 bridge, 0.4 mi (0.6 km) northwest of Trujillo Alto plaza, and 2.2 mi (3.5 km) northeast of Lago Loiza Reservoir. DRAINAGE AREA.--213 mi 1 (552 km 1 )' PERIOD OP RECORD.--Water years 1981 to current year. REMARKS: Plow controlled by Lago Loiza reservoir. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 13.. . DEC 15.. . PEB 1995 09.. . APR 11.. . JUN 20.. . AUG 16.. . DATE OCT 1994 13. .. DEC 15.. . PEB 1995 09.. . APR 11.. . JUN 20. . . AUG 16.. . DIS- PH CHARGE, SPE- WATER INST. CIPIC WHOLE CUBIC CON- FIELD TEMPER- TUR- OXYGEN, PEET DUCT- (STAND- ATURE BID- DIS- TIME PER ANCE ARD WATER ITY SOLVED SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) 0815 5.9 442 7.1 26.0 4.5 0.4 0955 7.9 441 7.7 26.0 1.9 4.8 1025 2.2 564 7.7 28.0 2.3 5.6 1035 5.3 499 7.4 27.5 5.2 5.6 0825 1.9 499 7.4 27.5 8.7 3.5 1020 E2.0 438 7.4 30.0 2.3 7.7 ALKA- MAGNE- SODIUM POTAS- LINITY CALCIUM SIUM, SODIUM, AD- SIUM, WAT WH DIS- DIS- DIS- SORP- DIS- TOT PET SULPIDE SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L AS CA) AS M6) AS NA) AS K) CACO3 AS S) 39 14 30 1 3.8 140 <0.5 150 190 37 15 30 1 2.9 130 <0.5 210 31 12 27 1 3.2 150 RESIDUE NITRO- SOLIDS, TOTAL NITRO- GEN, AM - DIS- AT 105 GEN, MONIA +• NITRO- PROS- OXYGEN, OXYGEN COLI- DIS- DEMAND, PORM, STREP- HARD- SOLVED CHEM- FECAL, TOCOCCI NESS (PER- ICAL 0.45 FECAL, TOTAL CENT (HIGH UM-MF (COLS. (MG/L SATUR- LEVEL) (COLS./ PER AS ATION) (MG/L) 100 ML) 100 ML) CACO3) 5 14 3100 230 160 59 10 120 80 70 15 K160 K20 70 17 K16000 3200 150 44 16 2300 840 101 14 K860 K1200 130 SOLIDS, CHLO- PLUO- SILICA, SUM OP SULPATE RIDE, RIDE, DIS- CONSTI- DIS- DIS- DIS- SOLVED TUENTS, SOLVED SOLVED SOLVED (MG/L DIS- (MG/L (MG/L (MG/L AS SOLVED AS S04) AS CL) AS P) SIO2) (MG/L) 40 32 0.10 23 260 __ __ 18 30 0.10 28 239 __ 16 27 0.10 26 232 CHRO- BARIUM, BORON, CADMIUM MIUM, TOTAL TOTAL TOTAL TOTAL' SOLVED DEG. C, ORGANIC ORGANIC GEN, PHORUS ARSENIC RECOV- RECOV- RECOV- RECOV- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE DATE OCT 1994 13. .. DEC 15. . . PEB 1995 09. .. APR 11. .. JUN 20. . . AUG 16. .. PER PENDED (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L DAY) (MG/L) AS N) AS N) AS N) AS P) AS 4.11 10 0.50 0.50 0.50 0.120 3 0.30 0.30 0.60 0.090 <1 0.40 0.40 0.40 0.130 3.39 12 0.50 0.50 0.50 0.130 21 0.80 0.69 0.80 0.120 E 1.25 4 0.60 0.59 0.60 0.140 AS) AS BA) AS B) AS CD) AS CR) 1 <100 50 <1 <1 _ _ <1 <100 40 <1 <1 _ _ E = Estimated K o non-ideal count 293 RIO GRANDE DE LOIZA BASIN 50059100 RIO GRANDE DE LOIZA BELOW TRUJILLO ALTO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 13... DEC 15. . . FEB 1995 09. .. APR 11. .. JUN 20. .. AUG 16. .. COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS FB) AS PB) AS MN) AS HG) AS SB) AS AG) AS ZN) AS CN) (UG/L) 550 10 430 180 <0.10 150 <0.10 10 <0.010 10 <0.010 (MG/L) 0.06 0.12 294 RIO GRANDE DE LOIZA BASIN 50061000 RIO GRANDE DE LOIZA AT CAROLINA, PR LOCATION.--Lat 18°22'39", long 65°57'08", Hydrologic Dnit 21010005, on upstream right bank of Highway 3 bridge, at Km 11.5, 0.5 mi (0.8 km) southeast of Carolina Plaza, 3.3 mi (5.3 km) west of Canovanae Plaza and 2.5 mi (4.0 km) southwest of Cerro San Jose, and 8.8 mi (14.2 km) downstream from Rio Grande de Loiza mouth. DRAINAGE AREA.--243 mi 1 (629 km 1 )- WATER-STAGE RECORDS PERIOD OF RECORD.--January 1991 to current year. GAGE.—Water-stage recorder. Elevation of gage is 32.8 ft (10.0 m), from topographic map. REMARKS.--Flow regulated by Lago Loiza Dam and also by tidal changes. Gage-height and precipitation satellite telemetry at station. EXTREMES FOR PERIOD OF RECORD.--Maximum gage-height, 33.18 ft (10.113 m), Jan. 6, 1992; minimum, 3.91 ft (1.192 m), Aug. 6, 1991. EXTREMES FOR CURRENT YEAR.--Maximum gage-height, 21.41 ft (6.525 m), September 6; minimum 4.27 ft (1.301 m) , May 18. DAY OCT NOV GAGE HEIGHT, FEET, JAN WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES FEB MAR APR MAY SEP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX MIN 5.41 5.45 5.42 5.38 5.40 5.44 5.41 5.36 5.98 5.58 5.44 5.42 5.43 5.62 5.81 5.59 5.61 6.18 6.60 7.19 5.90 5.51 6.94 8.20 6.95 6.32 5.18 5.84 5.20 5.23 5.32 8.20 5.18 A A A A A A A A A A A A A A 5.28 5.25 5.35 5.26 5.17 5.35 5.36 5.84 5.22 5.28 5.47 5.94 7.10 5.47 6.27 6.73 --- ___ ___ 6.33 7.56 6.71 5.42 5.86 5.53 5.15 5.18 5.18 5.21 5.42 5.45 5.26 5.12 5.06 5.10 5.07 5.40 5.45 5.22 5.06 5.00 5.04 5.06 5.17 5.54 5.47 5.52 5.44 5.49 5.71 7.56 5.00 5.95 6.11 6.28 6.49 6.66 6.36 5.13 5.11 5.31 5.61 6.11 6.64 5.07 4.92 5.02 5.04 5.25 5.12 5.18 5.25 5.14 5.36 5.61 5.83 6.06 6.38 6.73 5.48 4.85 4.81 4.81 6.73 4.81 4.82 4.88 5.05 5.27 5.41 5.59 5.83 6.04 6.23 6.43 6.61 6.72 6.79 5.09 5.08 5.35 5.60 5.79 6.20 6.48 5.25 5.26 6.09 5.49 5.29 6.98 6.75 7.07 ___ —— 7.07 4.82 5.76 5.16 5.40 5.05 4.82 4.78 5.44 4.85 4.70 4.77 4.82 5.30 6.01 5.39 5.17 5.37 5.25 4.96 4.90 4.89 4.91 5.04 5.26 5.40 5.60 5.70 5.90 6.10 6.20 6.30 6.20 6.30 4.70 5.08 5.05 5.19 5.36 5.50 5.67 5.79 5.89 6.00 6.16 6.33 6.50 6.67 6.74 6.82 6.87 .94 .81 .86 .85 .79 .84 .89 .99 5.11 5.29 5.42 5.53 5.59 5.67 --- 6.87 4.79 5.75 5.85 5.95 6.01 5.89 5.23 5.22 5.25 5.22 5.31 5.45 5.58 5.68 5.95 6.52 6.50 .90 .80 .80 .90 .90 .80 .80 .82 .79 4.89 5.09 5.37 5.41 5.28 5.39 6.52 4.79 5.54 5.86 6.13 5.35 5.16 5.19 5.30 5.45 5.63 6.23 6.61 5.33 5.24 5.24 5.33 5.36 5.38 5.38 5.33 5.31 5.36 5.38 5.39 5.32 5.28 5.30 5.37 5.78 5.66 5.51 --- 6.61 5.16 5.48 5.40 5.30 5.34 5.54 5.90 5.71 5.46 5.33 5.34 5.44 5.57 5.69 5.92 6.37 5.98 5.63 5.43 5.35 5.32 5.40 6.37 5.96 5.58 5.36 5.27 6.35 6.80 6.13 5.09 5.84 6.80 5.09 5.69 5.04 7.19 6.07 4.93 5.01 4.96 4.92 4.98 5.03 5.06 5.32 5.34 5.34 5.13 5.12 5.13 5.36 A A A A 5.52 6.03 6.04 6.06 5.33 5.31 5.25 5.30 6.94 ___ ___ 6.21 5.29 5.19 5.24 9.17 12.08 6.52 5.77 6.00 5.58 6.11 6.36 5.48 5.18 9.24 12.41 7.39 7.82 6.26 6.53 7.21 6.05 5.80 6.27 5.04 5.85 5.69 5.75 5.90 5.95 12.41 5.04 A No gage-height record RIO GRANDE DE LOIZA BASIN 50061800 RIO CANOVANAS NEAR CAMPO RICO, PR LOCATION.—Lat 18°19'08", long 65°53'21", Hydrologic Unit 21010005, at upstream sida of bridga, on pavad secondary road, 0.4 mi (0.6 km) northeast of junction of Highways 185 and 186, 1.5 mi (2.4 km) south of Campo Rico, and 4.4 mi (7.1 km) south of Lolza, DRAINAGE AREA.--9.84 mi> (25.48 km1 )• WATER-DISCHARGE RECORDS PERIOD OP RECORD.--March 1967 to currant yaar. GAGE.--Water-stage racordar and crast-staga gaga. Elavation of gaga is 225 ft (68 m), from topographic map. REMARKS.--Racords fair except thosa for estimated daily discharges and Mar. 5-23, which ara poor. DISCHARGE, CUBIC PEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 295 DAY OCT JAN FEE MAR APR MAY OUN AtJG SEP 1 4.2 4.2 2 3.9 3.9 3 e3 . 9 3.6 4 e3.7 3.3 5 e3.7 3.5 6 e3.6 48 7 e3.9 22 8 a4.2 45 9 e3.9 e35 10 a5.5 e31 11 «4.0 29 12 3.1 9.7 13 3.0 6.5 14 3.0 a4 . 8 15 3.6 a4.0 16 3.9 e3.7 17 3.3 e3 . 8 18 7.2 a4.8 19 5.0 4.9 20 43 4.3 21 13 aS.l 22 7.7 a6.2 23 87 a4.9 24 124 a4.0 25 29 all 26 12 all 27 7.4 12 28 6.0 8.6 29 5.1 66 30 a4.4 130 31 4.3 —— TOTAL 419.5 533.8 MEAN 13.5 17 . 8 MAX 124 130 MIN 3.0 3.3 AC-PT 832 1060 CPSM 1.38 1.81 IN. 1.59 2.02 STATISTICS OP MONTHLY MEAN MEAN 41.8 44.9 MAX 273 125 (WY) 1971 1985 MIN 6.74 6.66 (WY) 1968 1981 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK PLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW PLOW ANNUAL RUNOFF (AC-PT) ANNUAL RUNOFF (CPSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 49 50 52 57 37 29 23 17 14 12 12 11 9.7 9.4 8.7 7.4 7.3 7.7 7.1 6.4 6.4 7.2 7.4 7.0 6.6 6.5 6.5 8.8 7.2 6.4 6.0 502.7 16.2 57 6.0 997 1.65 1.90 DATA 33.0 116 1971 5.82 1968 POR 5.7 6.1 6.5 6.7 5.7 5.1 5.0 5.2 6.3 6.6 7.3 48 15 8.6 7.4 .7 .5 .5 .6 .4 .0 .0 3.6 3.7 3.9 84 64 90 22 all a9.3 468.4 15.1 90 3.6 929 1.54 1.77 a7.9 a7.1 a€.3 a6.8 a5.7 «6.5 a6.9 a7.6 a6.4 a6.6 5.8 5.2 5.1 4.9 4.8 5.3 5.4 6.2 7.7 9.8 21 22 8.4 6.7 158 53 a!35 164 --_ --_ 696.1 24.9 164 4.8 1380 2.53 2.63 POR WATER YEARS 1967 23.5 62.4 1969 6.66 1977 19.3 48.4 1988 4.04 1977 33 19 16 14 13 11 10 12 9.5 9.2 8.0 25 22 54 al6 all 9.2 9.2 a9.5 9.8 7.8 7.3 7.7 7.3 6.8 6.7 7.6 7.6 6.7 7.5 7.7 401.1 12.9 54 6.7 796 1.31 1.52 - 1995 14.1 36.2 1969 3.54 1977 1994 CALENDAR YEAR 3725 10 176 2 2 7390 1 14 20 5 3 .2 .2 Sap 20 .4 May 30 .€ Apr 21 .04 .08 .7 .0 7.6 6.7 7.3 7.0 7.0 7.1 6.5 6.4 6.6 6.4 6.9 30 12 8.3 9.6 11 8.7 7.6 7.9 7.1 6.8 7.6 6.1 5.3 5.5 5.3 5.8 5.8 5.7 5.5 237.1 7.90 30 5.3 470 .80 .90 5.3 5.3 5.4 7.6 9.9 8.6 7.0 7.1 10 6.2 5.2 4.7 4.2 6.8 6.5 8.4 6.8 5.2 5.0 5.3 4.7 4.6 4.3 4.0 3.9 3.9 5.2 5.9 13 13 7.1 200.1 6.45 13 3.9 397 .66 .76 5.8 14 36 11 5.7 4.7 5.0 5.2 3.8 3.4 24 15 8.5 5.4 6.2 12 8.0 4.5 3.5 3.5 3.7 4.1 3.8 3.4 3.2 2.9 130 26 7.9 4.6 —— 374.8 12.5 130 2.9 743 1.27 1.42 4.0 3.8 3.8 13 13 13 6.3 4.4 4.3 3.5 3.5 4.5 11 19 32 28 14 9.5 9.0 5.9 74 104 17 11 8.5 13 151 74 43 29 23 753.0 24.3 151 3.5 1490 2.47 2.85 26 33 188 30 19 16 17 17 17 11 10 9.5 8.9 8.5 8.4 8.0 9.6 31 102 27 16 13 21 30 21 15 13 13 29 80 54 901.9 29.1 188 8.0 1790 2.96 3.41 32 20 18 17 70 a586 a59 32 23 19 26 19 16 15 181 859 107 61 38 31 29 25 29 23 19 17 17 15 27 19 --- 2449 81.6 859 15 4860 8.30 9.26 , BY WATER YEAR (WY) 15.3 53.2 1971 4.36 1994 POR 1995 7937 21 859 2 3 3680 9 15740 2 30 43 7 3 28.9 93.2 1969 4.28 1974 WATER YEAR .5 .7 Sap 16 .9 Jun 26 .4 Oet 11 Sap 6 .45 Sap 6 .21 .01 .7 .9 18.6 63.7 1970 2.80 1974 18.9 63.7 1979 3.72 1974 WATER 26 58 10 3160 1 15000 13 19370 2 36 43 12 5 25.5 137 1979 5.69 1991 YEARS 1967 - .7 .0 .5 Oct 9 .80 Jul 24 .5 Jul 18 Sap 13 .10 Sap 13 .80 Jul 24 .72 .93 .0 33.5 103 1979 5.20 1967 1995 1971 1994 1970 1977 1977 1982 1982 1977 a Estimated 296 THIS PAGE WAS LEFT BLANK INTENTIONALLY /""> 3 X - -, ^'^ -\*'* A- J '^ s-* ^x^v^^J \< — ™\ ,*C "X l i | Dfair-oat bo^da*1 * ---W VX \ \\ !i j • - .- / \ \ \ \ ~"-< /, ? i! -' \ ••" . i / v ;. \ LAS PfEORAS 'X/-/«^» ~^-T' x'"V;" J ^ • x . \'\ ! y "^,'^v I / i"fe N\>^.^ '^< ^V'X ^....Ul "^^1; v ^ N* S- *A "" 4t"°*) ', : ^^, il /..^^- Xsc^ K? / >.. -hA f'-\ >\. ^X^ \5r Av'' ^ x f / i : ~—--. s^. °-, i re'; i —•• V-' - ,' M -, '- -a^Ci 1 v x_x ; —A ^fti >f_---._~ 'xxt, r-^ „.,* \r*" \, f' ^''^^i^Lr^l/' \ "ae EXPLANATION 0670 SURFACE-WATER STATION AND NUMBER QUALITY-OF-WATER STATION AND NUMBER DAILY SEDIMENT STATION AND NUMBER RF04 WELL AND WELL NUMBER 6 KILOMETERS 297 0 1 Figure 21.--Northeastern river basins the Rio Herrera to Rio Anton Ruiz basins. 298 RIO ESPIRITU SANTO BASIN 50063440 QUEBRADA SONADORA NEAR EL VERDE, PR LOCATION.—Lat 18°19'24", long 650 49'03", Hydrologic Unit 21010005, in Caribbean National Forest, at El Yunque, 0.6 mi (1.0 km) upstream from Rio Espiritu Santo, 0.2 mi (0.3 km) upstream from Highway 186, and about 1.2 mi (1.9 km) south of El Verde. DRAINAGE AREA.--1.01 mi 2 (2.62 km2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March 1983 to current year. GAGE.—Water-stage recorder and crest-stage gage. Elevation of gage is 1,230 ft (375 m), from topographic map. REMARKS.--Records poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT JAN AUG 1 2.6 1.1 2 1.6 .84 3 1.2 .73 4 1.0 .71 5 .92 .96 6 .84 10 7 .88 24 8 1.0 e4 . 0 9 1.4 e20 10 2.6 e3.5 11 1.7 el.l 12 .79 e.62 13 .60 e.50 14 .55 e.46 15 .46 e.38 16 .42 e.46 17 .46 e.42 18 .66 e.46 19 1.7 e.42 20 58 e.92 21 4.6 e5.0 22 13 e!4 23 18 8.4 24 18 3.4 25 6.3 13 26 3.2 23 27 2.3 14 28 1.7 5.9 29 1.4 27 30 1.4 46 31 1.4 —— TOTAL 150.68 231.28 MEAN 4.86 7.71 MAX 58 46 MIN .42 .38 AC-FT 299 459 CFSM 4.81 7.63 IN. 5.55 8.52 52 59 25 29 15 12 9.5 10 e20 e6.3 e9.7 e5.8 68.5 65.3 64.0 e3.7 e3.2 63.0 62.4 62.1 e2.3 2.2 2.7 2.1 1.6 2.0 1.5 6.2 2.0 1.0 .73 309.83 9.99 59 .73 615 9.90 11.41 STATISTICS OF MONTHLY MEAN DATA MEAN 5.86 10.1 MAX 17.1 20.1 (WY) 1986 1985 MIN .22 2.47 (WY) 1993 1991 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 8.12 21.6 1988 .95 1990 FOR 1.8 4.4 3.0 2.1 .82 .59 .41 .32 3.4 1.4 5.1 31 9.7 11 12 6.5 4.1 3.3 2.8 2.4 2.0 1.6 1.6 1.5 1.2 41 69 48 3.5 1.6 1.1 278.24 8.98 69 .32 552 8.89 10.25 .84 .66 .51 .45 .39 .33 .42 .60 .27 .19 2.3 .46 .18 .11 2.3 11 2.5 5.7 12 3.6 4.0 1.4 .70 .71 55 18 79 46 ___ —— 249.62 8.91 79 .11 495 8.83 9.19 FOR WATER YEARS 1983 6.72 10.8 1988 3.41 1985 6.55 12.0 1988 1.59 1992 5.7 2.3 1.7 6.6 7.1 1.4 12 4.8 15 3.3 1.3 6.6 20 5.2 1.7 1.2 1.0 .96 .90 .85 .80 .74 .70 .64 .59 .58 .61 .61 .55 .51 .48 106.42 3.43 20 .48 211 3.40 3.92 - 1995 3.13 14.7 1990 1.59 1993 1994 CALENDAR YEAR 1842 5 62 3650 5 67 14 1 .10 .05 Feb 20 .00 Apr 5 .01 Mar 31 .00 .85 .5 .14 .46 .43 .38 .31 .36 .35 .28 .26 .20 .18 .15 4.9 1.2 .57 9.8 16 3.0 .82 .49 .35 .33 .56 .43 .36 .33 .32 .30 .26 .18 .14 —— 43.70 1.46 16 .14 87 1.44 1.61 , BY WATER 4.87 9.99 1987 1.09 1984 FOR 1995 2698 7 79 791 7 5350 7 99 20 2 .16 .19 .26 39 56 35 14 11 11 4.3 2.2 2.0 .70 .27 43 42 11 5.6 7.3 6.6 16 4.8 2.5 2.0 1.3 1.5 18 5.4 48 8.9 8.0 407.98 13.2 56 .16 809 13.0 15.03 YEAR (WY) 8.58 15.9 1992 3.25 1994 6.0 25 44 4.8 2.5 12 5.8 2.2 1.7 1.6 26 17 15 6.9 12 23 4.2 2.5 1.9 4.0 4.4 2.1 1.3 .95 .76 .65 .57 .67 .71 .74 —— 230.95 7.70 44 .57 458 7.62 8.51 6.00 13.7 1987 .98 1985 WATER YEAR .86 .39 .11 .21 .56 .07 .32 .40 .3 .43 Feb 27 Feb 14 Apr 27 Oct 20 Oct 20 Feb 14 .75 .73 5.3 22 24 18 3.9 1.8 1.2 .91 .92 1.7 7.7 3.2 10 9.4 2.2 4.9 2.2 1.5 18 23 3.5 2.8 2.4 2.2 63 27 7.4 12 3.2 286.81 9.25 63 .73 569 9.16 10.56 6.70 12.8 1983 2.36 1991 5.7 7.0 32 2.8 1.7 2.2 6.9 13 4.8 2.9 1.7 1.2 .95 .82 .70 .68 1.4 22 15 3.2 4.5 9.3 16 6.0 3.3 1.5 1.2 1.2 15 13 5.1 202.75 6.54 32 .68 402 6.48 7.47 6.74 14.5 1988 .53 1993 WATER YEARS 1983 6.73 9.48 4.09 216 .00 .01 2230 9.42 .00 4880 6.67 90.58 17 2.7 .42 Dec Aug Mar Dec Dec Aug 2.1 1.2 1.1 .90 14 52 3.7 11 2.4 1.7 7.1 3.7 1.8 1.0 8.9 640 67.0 63.6 62.4 62.5 63.1 62.1 el. 7 el. 5 el. 3 el. 2 el. 2 1.5 16 2.9 —— 200.60 6.69 52 .90 398 6.62 7.39 6.36 15.6 1989 2.34 1986 - 1995 1988 1994 7 1987 14 1993 31 1994 7 1987 7 1987 14 1993 e Estimated RIO ESPIRITU SANTO BASIN 50063500 QUEBRADA TORONJA AT EL VERDE, PR LOCATION.--Lat 18°19'43", long 65°49'14", Hydrologic Unit 21010005, in Caribbean National Forest, at downstream side of culvert on Highway 186, 0.2 mi (0.3 km) upstream from Rio Espiritu Santo, and about 0.9 mi (1.4 km) south of El Verde. DRAINAGE AREA.--0.064 mi 2 (0.166 km 2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--April 1983 to current year. GAGE.—Water-stage recorder, crest-stage gage and concrete broad-V-notch crested weir. Elevation of gage is 876 ft (267 m), from topographic map. REMARKS.--Records poor. Gage-height satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 299 OCT DEC APR JUN JUL AU6 SEP 1 e.14 e.15 2 e.12 e.16 3 e.13 e.14 4 e.ll e.15 5 e.ll e.12 6 e.ll e.36 7 e.15 e2.1 8 e.13 e6.4 9 e.13 e.95 10 e.ll e4.9 11 e.10 e.76 12 e.10 e.27 13 e.10 e.15 14 e.09 e.12 15 e.08 e.ll 16 e.09 e.09 17 e.13 e.ll 18 e.15 e.10 19 e.12 e.ll 20 el. 9 e.10 21 e.21 e.22 22 e.29 e.18 23 e.54 e.10 24 6.68 6.08 25 6.24 6.23 26 6.19 e.57 27 6.18 6.90 28 6.16 6.19 29 6.17 62.0 30 6.17 63.3 31 e.16 — - TOTAL 7.09 25.12 MEAN .23 .84 MAX 1.9 6.4 MZN .08 .08 AC-FT 14 50 CFSM 3.81 14.0 IN. 4.40 15.57 65.6 69.5 63.0 e3.7 el.l el.O e.54 e.47 e.93 e.38 e.36 e.33 e.27 e.23 6.21 6.18 6.18 e.15 e.13 e.13 6.18 e.24 e.22 6.21 e.18 e.15 6.19 e.26 e.17 6.19 e.17 30.55 .99 9.5 .13 61 16.4 18.94 e.14 e.16 6.19 e.15 e.17 e.15 e.17 e.15 e.26 e.18 e.18 el. 3 e.29 e.23 e.17 e.14 e.14 e.15 e.17 e.13 e.14 e.14 e.15 e.14 e.17 6.51 e5.0 e6.2 6^35 e.23 6.19 17.84 .58 6.2 .13 35 9.59 11.06 STATISTICS OF MONTHLY MEAN DATA FOR WATER MEAN .29 .67 MAX 1.35 1.56 (WY) 1986 1993 MIN .059 .15 (WY) 1992 1991 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS. 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS .53 1.55 1993 .091 1990 FOR .38 1.39 1993 .14 1986 e.22 e.20 6.21 e.17 e.18 e.14 e.20 e.20 e.16 e.17 e.24 e.15 e.18 e.14 e.20 e.25 6.21 e.56 e.93 e.35 e.25 e.18 e.59 e.23 e5.5 el. 8 e!2 e6.5 ___ ___ —— 32.11 1.15 12 .14 64 19.1 19.91 YEARS 1983 .34 1.15 1995 .092 1987 1994 CALENDAR YEAR 119. . 9. . 238 5. 74. . . 85 33 5 00 00 47 31 54 12 03 Dec 2 Mar 13 Mar 30 6.91 e.62 e.50 e.70 e.45 e.29 e2.0 6.44 6.55 e.29 e.27 e.26 e.37 e.26 .11 .11 .13 .13 .24 .22 .12 .13 .14 .15 .10 .28 .13 .11 6.21 62.1 e.23 el. 9 e.17 e.14 e.ll e.17 e.17 e.13 e.13 e.10 e.13 e.10 e.22 e.22 e.22 6.19 .23 .21 .20 .13 .11 .13 .10 .07 .06 .07 .05 .07 .04 .04 e.14 —— 10.69 7.61 .34 .25 2.0 2.1 .10 .04 21 15 5.75 4.23 6.63 4.72 6.03 6.03 6.04 e.37 el. 2 e.12 e.05 e.04 e.04 6.03 e.09 e.12 e.54 e.07 e.94 e.25 e.05 6.03 e.ll e.06 e.ll e.05 e.04 e.03 e.03 e.04 e.18 e.14 e.40 e.76 e.25 6.24 .20 1.2 .03 12 3.35 3.87 e.09 e.26 e.35 e.08 e.04 e.12 e.10 e.05 e.04 e.03 e.15 e.70 e.29 e.13 e.ll e.14 e.09 e.06 e.05 e.07 e.08 e.06 e.05 e.04 e.04 e.04 e.04 e.ll e.06 e.04 --- 3.51 .12 .70 .03 7.0 1.95 2.18 e.04 e.04 e.04 e.33 e.50 e.34 e.10 e.06 e.05 e.05 e.05 e.18 e.43 e.32 e.33 6.41 e.14 e.13 e.ll e.07 e.90 e.98 e.25 e.16 e.14 6.19 e4.9 e.90 e.40 e.30 e.20 13.04 .42 4.9 .04 26 7.01 8.08 6.49 6.41 el. 4 e.25 e.15 e.12 e.12 e.47 e.30 e.13 e.ll e.09 e.08 e.07 e.06 e.07 e.10 e.42 e.64 6.21 e.16 e.16 e.40 e.60 6.21 e.15 e.14 e.16 e.56 e.62 e.36 9.21 .30 1.4 .06 18 4.95 5.71 e.20 e.13 e.10 e.09 e.25 el. 8 e.40 e.23 e.18 e.14 e.34 e.20 e.14 e.12 e.60 e8.2 e.67 e.27 6.21 e.24 e.54 e.29 e.17 e.15 e.14 e.13 e.12 e.12 e.33 e.17 16.67 .56 8.2 .09 33 9.26 10.34 - 1995, BY WATER YEAR (WY), .22 .21 .63 .61 1990 1987 .016 .035 1994 1984 .37 1.17 1993 .080 1994 .27 .61 1987 .056 1991 FOR 1995 WATER YEAR 179.68 .49 12 .03 .04 32 1.93 356 8.20 111.40 .82 .17 .06 Feb 27 May 1 Apr 27 Nov 8 Nov 8 .35 1.70 1993 .046 1991 .27 .54 1988 .054 1993 WATER YEARS 1983 .35 .78 .17 12 .00 .00 101 2.61 .00 253 5.82 79.08 .70 .15 .05 May Mar Mar Aug Aug Apr .32 .61 1989 .060 1991 - 1995 1993 1984 2 1993 13 1994 30 1994 13 1990 13 1990 10 1983 e Estimated 300 RIO ESPIRITU SANTO BASIN 50063800 RIO ESPIRITU SANTO NEAR RIO GRANDS, PR LOCATION.--Lat 18°21'37 n , long 65°48'49 n , Hydrologic Unit 21010005, at downstream side of bridge on Highway 966, 0.1 mi (0.2 km) upstream from Quebrada Jimenez, and 1.9 mi (3.1 km) southeast of Rio Grande. DRAINAGE AREA.--8.62 mi 1 (22.33 km1 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1959 to April 1963 (annual low-flow and occasional measurements only), August 1966 to current year. GAGE.—Water-stage recorder and crest-stage gage. Elevation of gage is 40 ft (12 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. REVISIONS.--The maximum discharge for period of record has been revised to 21,200 ft'/s (600 m'/s), Aug. 13, 1990, gage-height, 16.62 ft (5.06 m). DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DEC MAR SEP 1 15 el2 2 14 ell 3 14 elO 4 15 e9.3 5 14 e8.8 6 14 e80 7 15 e90 8 16 e360 9 15 e!50 10 18 el80 11 21 e64 12 16 e25 13 13 e!9 14 14 e!8 15 14 e!6 16 14 e!5 17 14 e!9 18 15 e21 19 16 e!3 20 332 e!2 21 21 e38 22 51 e52 23 67 27 24 98 16 25 37 53 26 e26 59 27 e!9 92 28 e!6 33 29 el4 157 30 el2 221 31 e!3 —— TOTAL 993 1881.1 MEAN 32.0 62.7 MAX 332 360 MIN 12 8.8 AC-FT 1970 3730 CFSM 3.72 7.27 IN. 4.29 8.12 STATISTICS OF MONTHLY MEAN MEAN 60.5 84.8 MAX 202 196 (WY) 1971 1985 MIN 12.3 29.1 (WY) 1969 1982 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 307 408 128 150 76 65 46 46 91 33 40 28 34 27 23 20 e20 e!8 e!7 e!7 15 14 15 e!8 e!7 el 5 el4 e41 e23 el 9 e!8 1803 58.2 408 14 3580 6.75 7.78 DATA 73.2 179 1971 16.8 1994 FOR el8 e22 e26 e28 el9 e!7 el6 e!5 e24 e24 e30 e340 e70 e39 e45 e32 e24 e21 e!9 e!8 e!7 e!6 e!5 e!6 e!5 e260 e250 e280 e62 e33 e25 1836 59.2 340 15 3640 6.87 7.92 e23 el9 e!8 el 6 e!5 e!4 e!4 e!6 e!8 e!5 e!7 el6 e!3 e!2 e!2 e20 e21 e21 e58 e58 e85 e46 e68 el 8 e300 el60 e520 e420 —— 2033 72.6 520 12 4030 8.42 8.77 FOR WATER YEARS 1966 52.4 119 1969 18.5 1977 50.1 117 1982 10.8 1983 el20 e45 e35 e38 e45 e29 e64 e68 e60 e42 e27 e93 el20 e!60 e49 e31 e27 e25 e21 e20 e!9 e!8 e!7 e!6 el5 el4 el6 e!5 el3 el3 e!2 1287 41.5 160 12 2550 4.82 5.55 - 1995 39.6 153 1990 10.2 1994 1994 CALENDAR YEAR 10250.1 28.1 408 5.0 5.6 20330 3.26 44.23 58 14 6.6 Dec 2 Aug 4 Aug 2 ell elO e9.8 e9.6 e9.3 elO e9.6 e8.8 e8.6 e8.6 e8.6 e49 e!4 ell e35 e52 e20 el5 e!3 ell e9.6 ell e9.8 e8.8 e!3 e8.2 e8.6 e7.6 e7.2 e7.8 —— 415.5 13.8 52 7.2 824 1.61 1.79 e7.8 e7.3 e7.3 e8.2 e9.2 elO e23 e!5 e!3 e8.4 e7.8 e9.3 e!20 e!5 e210 e40 e9.2 e7.4 e22 e!2 e22 e9.0 e7.2 e6.4 e6.4 e7.3 e35 e27 e72 el50 e40 944.2 30.5 210 6.4 1870 3.53 4.07 e!2 e35 e49 ell e7.4 el8 e!3 e6.4 e5.6 e4.8 e20 elOO e40 e!7 e!6 e20 e!2 e8.2 e7.6 elO ell eS.O e6.2 e6.0 e5.8 e6.2 e5.4 e!5 eS.O e6.4 ___ 491.0 16.4 100 4.8 974 1.90 2.12 e5.8 e5.4 e7.4 e48 e82 e60 ell 10 9.6 7.9 8.6 12 21 15 20 33 9.6 12 9.9 7.1 102 91 19 16 18 12 365 104 40 38 26 1226.3 39.6 365 5.4 2430 4.59 5.29 44 69 222 37 26 25 36 80 58 35 28 29 34 31 e28 e28 e28 el51 e!65 e30 e20 e25 e52 e38 e21 e!6 e!6 e!6 e56 e26 e!6 1486 47.9 222 16 2950 5.56 6.41 el6 e!6 e!6 e!5 23 251 18 26 15 11 29 14 12 e8.6 e70 e380 e64 e35 e23 e24 e30 e20 el6 e!4 e!3 el2 ell 27 129 35 --- 1373.6 45.8 380 8.6 2720 5.31 5.93 , BY WATER YEAR (WY) 43.2 119 1981 6.27 1984 FOR 1995 15769. 43. 520 4. 6. 2710 7. 31280 5. 68. 92 18 8. 67.3 185 1979 14.9 1973 WATER YEAR 7 2 Feb 27 8 Jun 10 9 Jun 21 Oct 20 02 Oct 20 01 05 6 45.3 120 1970 10.0 1975 50.6 114 1983 11.1 1975 WATER 57 98 21 2600 4 4 21200 16 41270 6 89 122 25 10 59.1 123 1988 18.5 1994 YEARS 1966 .0 .6 .6 Dec .1 Jul .4 Jun Aug . 62 Aug .61 .80 56.5 191 1989 17.7 1971 - 1995 1979 1994 7 1987 3 1975 30 1975 13 1990 13 1990 e Estimated RIO ESPIRITU SANTO BASIN 50063800 RIO ESPIRITU SANTO NEAR RIO GRANDS, PR--Continued HATER-QUALITY RECORDS PERIOD OF RECORD.--Hater years 1958, 1961-66, 1968 to current year. HATER-QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 301 DATE OCT 1994 18. . . DEC 09. . . PEB 1995 07. .. APR 21. . . JUN 12. .. AUG 11. . . DATE OCT 1994 18. .. DEC 09. . . FEE 1995 07. .. APR 21. .. JUN 12... AUG 11... TIME 0815 0755 0850 0900 1045 0815 HARD- NESS TOTAL (M6/L AS CACO3) 33 _- 35 42 — 25 SILICA, DATE OCT 1994 18. .. DEC 09. . . PEB 1995 07. .. APR 21. .. JUN 12. .. AUG 11... K = non- ideal DIS- SOLVED (MG/L AS SI02) 19 __ 21 23 -- 15 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 17 112 14 9.6 25 28 CALCIUM DIS- SOLVED (M6/L AS CA) 7.5 -- 7.5 9.2 — 5.6 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 73 __ -- 80 -- 59 SPE- CIFIC CON- DUCT- ANCE (US /CM) 100 53 114 114 68 70 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 3.5 -- 3.9 4.5 — 2.6 SOLIDS, DIS- SOLVED (TONS PER DAY) 3.40 __ — 2.09 — 4.38 PH HATER WHOLE FIELD (STAND- ARD UNITS) 6.9 6.4 6.8 6.7 6.6 6.4 SODIUM, DIS- SOLVED (MG/L AS NA) 7.5 __ 7.9 9.0 -- 6.4 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 3 17 2 3 4 2 TEMPER- ATURE HATER (DEG C) 25.0 22.0 22.0 24.0 23.0 26.0 SODIUM AD- SORP- TION RATIO 0.6 __ 0.6 0.6 — 0.6 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 0.40 <0.20 <0.20 0.21 0.26 TUR- BID- ITY (NTU) 5.4 16 1.5 1.2 4.7 4.0 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 0.60 __ 0.70 0.80 -- 0.50 PHOS- PHORUS TOTAL (MG/L AS P) 0.030 0.020 <0.010 <0.010 0.020 0.020 OXYGEN, DIS- SOLVED (MG/L) 6.6 6.0 6.0 5.4 8.2 8.4 ALKA- LINITY HAT HH TOT PET FIELD MG/L AS CACO3 39 13 35 35 16 30 ARSENIC TOTAL (UG/L AS AS) <1 __ — 1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 78 72 67 63 95 103 SULFIDE TOTAL (MG/L AS S) <0.5 __ __ <0.5 -- ~- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -_ -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 26 12 <10 14 <10 SULFATE DIS- SOLVED (MG/L AS SO4) 2.3 -_ 0.70 1.9 — 1.9 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 20 __ -- 30 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS. / 100 ML) 2100 540 K2100 460 320 K620 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 9.5 -- 10 11 -- 8.8 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 3300 470 370 920 180 2700 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 -- <0.10 <0.10 -- <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 -- — 302 RIO ESPIRITO SANTO BASIN 50063800 RIO ESPIRIT0 SANTO NEAR RIO GRANDE, PR--Continued HATER-QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 18. .. DEC 09. .. FEB 1995 07. .. APR 21... JTJN 12. . . AUG 11. .. COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) 310 280 20 <0.10 30 0.20 <0.010 <0.010 (MG/L) <0.02 0.03 RIO ESPIRITU SANTO BASIN 50064200 RIO GRANDE NEAR EL VERDE, PR LOCATION.--Lat 18°20'42", long 65°50'30", Hydrologic Unit 21010005, on left bank 250 ft (7.6 m) upstream side of bridge at Hwy 960, 0.05 mi (0.08 km) southwest of junction of Highways 956 and 960, 1.1 mi (1.8 km) west of El Verde, and 2.7 mi (4.3 km) south of Rio Grande. DRAINAGE AREA.--7.31 mi 1 (18.93 km1 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.—Hay 1967 to December 1970, January 1972 to September 1982, August 1990 to current year. GAGE.—Water-stage recorder. Elevation of gage is 131 ft (40 m), from topographic map. REMARKS.—Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 303 JAN FEB SEP 1 6.8 7.1 2 6.1 6.7 3 5.6 6.3 4 5.3 5.9 5 5.2 5.8 6 5.2 43 7 5.6 48 8 6.0 196 9 5.7 82 10 8.0 97 11 6.9 42 12 5.4 16 13 4.8 11 14 12 9.6 15 24 8.4 16 6.9 7.9 17 5.3 9.8 18 10 11 19 13 7.0 20 194 6.4 21 19 20 22 21 27 23 93 12 24 103 7.7 25 36 26 26 15 26 27 11 65 28 9.1 22 29 8.1 113 30 7.3 154 31 7.6 —— TOTAL 671.9 1099.6 MEAN 21.7 36.7 MAX 194 196 MIN 4.8 5.8 AC-FT 1330 2180 CFSM 2.97 5.01 IN. 3.42 5.60 127 153 87 100 81 59 39 34 47 26 24 22 23 20 19 16 14 14 13 12 11 11 12 13 12 11 10 19 11 9.0 8.6 1057.6 34.1 153 8.6 2100 4.67 5.38 8.6 10 12 13 9.0 7.9 7.3 7.1 11 11 14 132 26 15 17 13 9.3 8.0 7.6 7.3 6.8 6.5 6.4 6.6 6.2 136 139 141 28 17 13 852.6 27.5 141 6.2 1690 3.76 4.34 STATISTICS OF MONTHLY MEAN DATA FOR WATER MEAN 59.1 70.0 MAX 392 172 (WY) 1971 1970 MIN 8.45 14.3 (WY) 1969 1981 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 48.9 140 1971 13.8 1968 FOR 42.0 151 1969 10.1 1977 12 10 9.2 8.7 8.4 7.9 7.7 13 9.4 7.8 8.5 8.2 6.9 6.3 6.3 9.2 14 14 26 26 39 21 31 8.2 137 71 239 179 ___ ___ —— 944.7 33.7 239 6.3 1870 4.62 4.81 YEARS 1967 30.9 76.4 1969 5.80 1977 33 20 16 17 20 13 29 31 27 18 12 41 53 71 21 14 12 11 9.7 9.2 8.9 8.2 7.5 7.2 6.7 6.3 6.9 6.8 5.9 5.9 5.3 553.5 17.9 71 5.3 1100 2.44 2.82 - 1995 21.5 54.4 1969 4.50 1977 1994 CALENDAR YEAR 7133. 19. 293 3. 3. 14150 2. 36. 42 9. 4. 5 5 Feb 20 0 Aug 7 3 Jul 22 67 30 1 5 5.0 4.6 4.5 4.4 4.2 4.5 4.3 3.9 3.8 3.8 3.8 22 6.4 4.9 15 23 8.9 6.6 e6.1 5.3 4.7 5.4 4.7 e4.2 e6.0 e3.9 e4.0 e3.6 e3.5 e3.7 —— 188.7 6.29 23 3.5 374 .86 .96 , BY WATER 28.4 119 1978 6.29 1995 e3.7 e3.5 e3.5 e3.9 e4.5 e4.8 ell e7.0 e6.0 e4.0 e3.8 e4.5 e56 e7.4 elOO e30 eS.O e3.7 e!2 e6.4 e!2 e4.8 e4.0 e3.5 e3.5 e4.0 e!9 e!5 e40 e80 e29 495.5 16.0 100 3.5 983 2.19 2.52 YEAR (WY) 54.1 203 1969 10.2 1974 e8.8 e27 e37 e8.2 e4.6 e!3 elO e4.8 e4.0 e3.5 e!5 e76 e35 e!3 e!2 e!5 elO e6.2 e5.6 e7.6 e8.2 e5.8 e4.8 e4.5 e4.3 e4.6 e4.1 ell 5.9 4.4 —— 373.9 12.5 76 3.5 742 1.70 1.90 31.4 86.5 1968 6.22 1975 FOR 1995 WATER YEAR 9779.8 26.8 439 3.5 3.6 2320 10.94 3.4 19400 3.67 49.77 65 12 4.6 Sep 16 Apr 29 Apr 28 Sep 6 Sep 6 Jul 2 3.9 3.6 4.7 31 53 37 12 7.0 5.6 5.3 5.1 16 45 33 34 43 15 14 12 7.2 94 101 26 17 14 20 205 108 43 32 21 1068.4 34.5 205 3.6 2120 4.71 5.44 36.9 109 1969 8.66 1994 WATER 41 87 17 3470 2 2 17400 15 1 29700 5 76 80 17 6 51 43 125 24 15 12 12 49 30 13 11 9.0 8.0 7.3 6.6 6.7 10 37 86 22 17 17 40 66 25 16 15 16 59 64 44 956.6 30.9 125 6.6 1900 4.22 4.87 42.3 90.0 1968 7.39 1991 YEARS 1967 .0 .1 .3 May .2 Aug .5 Aug sep . 50 Sep .6 Mar .61 .19 .6 23 13 11 9.8 63 314 43 25 20 15 37 21 15 12 77 439 77 46 27 28 34 24 19 16 15 14 13 13 35 18—— 1516.8 50.6 439 9.8 3010 6.92 7.72 48.2 153 1975 12.4 1967 - 1995 1969 1994 21 1969 15 1991 10 1991 16 1975 16 1975 13 1977 e Estimated 304 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA, PR LOCATION.--Lat 18°19'46", long 65°45'04", Hydrologic Unit 21010005, on left bank, at bridge on Highway 988, 1.4 mi (2.3 km) west of Sabana, 2.0 mi (3.2 km) downstream from Rio de la Mina, and 3.2 mi (5.1 km) southeast of Mameyes. DRAINAGE AREA.--6.88 mi 2 (17.82 km2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.—August 1967 to December 1973, June 1983 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 275 ft (84 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 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY DEC JUN 1 e!7 18 2 e!3 15 3 e!3 15 4 elO 16 5 10 15 6 10 97 7 11 134 8 12 128 9 22 120 10 70 160 11 31 86 12 20 38 13 17 29 14 20 24 15 14 22 16 13 20 17 14 31 18 15 21 19 25 19 20 151 23 21 33 83 22 73 55 23 97 33 24 79 21 25 36 51 26 24 48 27 21 75 28 19 32 29 18 77 30 19 119 31 18 - — TOTAL 945 1625 MEAN 30.5 54.2 MAX 151 160 MIN 10 15 AC-FT 1870 3220 CFSM 4.43 7.87 IN. 5.11 8.79 STATISTICS OF MONTHLY MEAN MEAN 65.4 81.3 MAX 240 191 (WY) 1971 1985 MIN 20.3 36.3 (WY) 1969 1974 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 128 297 100 113 67 53 40 37 45 30 33 24 31 28 24 22 38 25 22 20 19 23 26 29 40 27 26 40 28 26 25 1486 47.9 297 19 2950 6.97 8.03 33 38 32 28 25 23 22 21 39 27 34 87 51 50 49 37 29 26 24 23 23 22 21 22 19 127 146 157 45 33 28 1341 43.3 157 19 2660 6.29 7.25 DATA FOR WATER 60.6 164 1971 16.6 1990 FOR 53.5 105 1969 25.0 1985 24 24 22 21 20 20 23 24 20 19 29 21 19 18 32 53 40 35 49 40 69 38 28 26 203 54 234 219 -__ ___ —— 1424 50.9 234 18 2820 7.39 7.70 YEARS 1967 42.4 68.0 1988 21.7 1968 52 37 31 47 46 29 92 47 e!24 e49 e32 e39 e73 e50 e35 31 27 26 24 23 22 22 20 20 20 19 19 18 17 17 17 1125 36.3 124 17 2230 5.27 6.08 - 1995 38.3 79.7 1990 18.1 1968 1994 CALENDAR YEAR 12222. 33. 509 7. 10 24240 4. 66. 66 22 13 2 5 Feb 19 5 Aug 13 Aug 11 87 09 17 16 15 14 20 16 15 14 14 13 14 32 19 17 26 55 24 19 18 17 17 17 17 16 16 15 15 15 14 14 551 18.4 55 13 1090 2.67 2.98 13 12 11 31 53 41 28 36 26 17 13 19 38 22 254 120 27 19 23 34 46 20 15 14 19 36 117 70 175 119 86 1554 50.1 254 11 3080 7.29 8.40 61 90 139 55 42 81 61 42 37 36 198 153 107 70 81 88 56 44 40 47 48 38 33 34 37 30 28 23 20 22 1841 61.4 198 20 3650 8.92 9.95 19 19 29 50 59 50 26 26 24 24 20 26 35 22 33 34 27 37 25 24 44 84 43 33 42 42 171 107 58 57 37 1327 42.8 171 19 2630 6.22 7.18 53 70 107 51 42 46 79 70 53 43 41 51 42 29 23 23 49 104 119 53 63 60 59 53 44 36 33 35 60 62 48 1701 54.9 119 23 3370 7.98 9.20 45 39 39 45 96 193 49 72 42 42 61 46 38 31 36 326 99 57 45 46 59 44 37 34 31 31 32 35 54 34 --- 1838 61.3 326 31 3650 8.91 9.94 , BY WATER YEAR (WY) 39.8 83.1 1973 14.5 1984 FOR 1995 16758 45 326 10 11 3280 6 33240 6 90 96 33 16 65.8 147 1970 18.7 1973 WATER YEAR .9 Sep 16 Oct 4 Oct 2 May 15 .99 May 15 .67 .61 56.1 112 1970 12.4 1985 49.5 93.4 1969 20.3 1994 WATER 55 78 33 2780 6 9 20500 13 5 40420 8 110 102 33 16 52.9 81.4 1988 20.4 1994 YEARS 1967 - .8 .0 .1 Sep 18 .9 Apr 20 .4 Jun 12 Sep 18 .91 Sep 18 . 1 Apr 8 .11 .19 56.0 166 1989 26.6 1986 1995 1971 1994 1989 1970 1985 1989 1989 1970 e Estimated RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA,PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1992 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1992 to September 1995. INSTRUMENTATION.— Automatic sediment sampler, since 1993. REMARKS:-- Sediment samples were collected by a local observer on a weekly basis and during high flow events. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 203 mg/L December 29, 1992; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 1,490 tons (1,340 tonnes) December 17, 1982; Minimum daily mean, 0.03 tons (0.02 tonne) October 05, 1994. 305 EXTREMES FOR WATER YEARS 1993, 1995-- Water Suspended-sediment concentration (mg/1) Year maximun daily minimun daily Suspended-sediment discharge (tons per day) maximun daily minimun daily 1993 1994 1995 203 125 78 (dec. 29) (feb. 19) (sep. 16) SEDIMENT DISCHARGE, SUSPENDED DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MEAN DISCHARGE (CFS) 22 19 17 23 25 49 28 25 26 26 21 22 20 19 IB 19 19 19 19 31 21 46 30 21 20 19 19 18 25 27 61 MEAN CONCEN- TRATION (MG/L) OCTOBER 3 3 2 3 3 12 6 5 5 4 4 4 3 3 3 3 2 2 2 4 2 6 4 3 3 2 2 2 3 3 11 SEDIMENT DISCHARGE (TONS/DAY) 1 (several 1 (several 1 (several (TONS/DAY), MEAN DISCHARGE (CFS) days) days) days) 1490 446 293 WATER YEAR OCTOBER MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS /DAY) (dec. 29) (feb. 19) (sep. 16) 0.07 (dec. 17) eO.02 (aug. 13) 0.03 (oct. 05) 1992 TO SEPTEMBER 1993 MEAN DISCHARGE (CFS) NOVEMBER .17 .13 .11 .25 .21 4.9 .48 .37 .33 .31 .22 .21 .18 .15 .14 .13 .12 .11 .11 .38 .11 1.7 .33 .16 .14 .12 .12 .10 .24 .22 2.1 40 51 84 331 68 65 48 40 48 141 36 39 35 49 39 85 62 181 65 79 70 199 68 63 53 40 101 108 145 105 ___ 8 7 13 168 12 9 8 6 12 31 5 5 5 8 7 23 11 42 9 15 13 34 11 9 8 6 18 22 32 18 .98 1.0 3.6 367 2.4 1.8 1.1 .78 1.6 35 .48 .75 .49 1.4 .79 12 2.1 30 1.7 6.1 3.7 20 2.1 1.5 1.2 .63 5.7 9.2 23 6.2 52 44 42 80 41 86 37 33 30 28 28 25 25 28 35 26 23 25 24 24 23 71 31 68 70 246 73 87 678 262 146 MEAN CONCEN- TRATION (MG/L) DECEMBER 6 3 4 15 9 29 6 6 6 6 5 5 5 5 3 1 1 1 2 2 3 11 4 12 14 113 15 19 203 52 19 SEDIMENT DISCHARGE (TONS /DAY) .78 .41 .47 4.0 .99 20 .60 .51 .46 .42 .40 .36 .35 .39 .35 .10 .07 .08 .10 .13 .16 3.3 .34 2.7 2.9 112 3.1 5.0 1490 60 8.1 TOTAL 774 14.35 2538 544.30 2491 1718.57 306 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA,PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1992 TO SEPTEMBER 1993 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATXON DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 108 89 67 e56 e94 e96 e72 e54 e46 e46 e45 e43 50 52 47 45 34 29 29 27 24 174 54 34 104 36 57 105 178 62 53 20 15 10 9 8 8 7 7 6 6 6 5 8 7 6 5 5 4 3 3 2 27 8 5 21 7 8 23 34 10 8 6.6 4.3 2.1 el. 4 el.l .98 .91 .84 .78 .72 .67 .62 1.2 1.0 .87 .65 .41 .31 .25 .20 .15 26 1.4 .50 8.9 .68 1.3 23 22 1.7 1.1 FEBRUARY 46 47 50 48 42 39 37 35 32 31 30 97 44 34 30 27 28 28 25 161 129 42 60 40 32 e30 e32 e28 ___ ___ 6 6 8 6 4 3 2 2 1 1 1 19 6 4 4 3 3 3 3 25 20 6 10 6 5 4 4 3 ___ .80 .81 1.0 .73 .49 .33 .24 .17 .12 .09 .12 9.9 .69 .39 .30 .23 .23 .22 .21 26 8.8 .65 2.2 .66 .39 e.33 e.29 e.25 ___ MARCH e28 e39 e32 e26 25 24 24 29 23 22 21 20 26 21 25 83 45 32 68 34 26 22 76 95 35 40 28 29 24 23 24 3 3 2 2 2 2 3 3 2 2 2 2 2 2 2 17 7 6 10 4 3 3 12 17 4 5 4 3 3 3 3 e.22 e.19 e.17 «.15 .14 .15 .18 .26 .13 .12 .11 .11 .14 .12 .19 10 .93 .62 2.3 .35 .25 .19 3.3 6.4 .42 .61 .29 .27 .21 .18 .17 TOTAL 2010 112.64 1304 56.64 1069 28.87 e Estimated RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1992 TO SEPTEMBER 1993 307 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TOMS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 IB 19 20 21 22 23 24 25 26 27 28 29 30 31 28 26 51 24 25 23 20 19 62 35 22 22 31 26 22 38 36 51 32 43 32 21 20 18 19 28 32 34 65 526 ___ APRIL 2 2 6 3 2 2 2 3 13 4 3 3 4 4 4 6 5 10 6 7 5 3 3 2 2 3 3 4 30 94 ___ .17 .15 .91 .18 .16 .13 .13 .16 6.7 .50 .18 .18 .42 .28 .24 .95 .62 2.3 .48 1.3 .44 .19 .15 .12 .11 .23 .26 .42 48 406 ___ MEAN DISCHARGE (CPS) 145 250 127 46 43 32 32 74 e205 e62 e35 e27 e27 159 46 35 30 30 e28 e33 e31 e28 e28 e31 92 50 236 65 40 59 68 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) MAY MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) JUNE 28 46 19 7 6 5 4 15 33 9 5 2 3 29 7 7 6 6 5 5 5 5 4 4 18 11 73 8 5 8 16 19 40 9.8 .91 .93 .42 .36 13 e34 el. 6 e.48 e.16 e.23 15 .89 .62 .50 .47 .41 .46 .41 .35 .33 .35 5.0 1.9 50 1.6 .54 1.4 4.7 75 53 48 44 39 37 42 41 42 74 37 32 66 39 74 49 31 37 274 e!26 e43 77 42 39 44 51 39 33 45 89 12 4 4 4 3 3 3 2 2 8 5 4 11 5 13 6 2 4 141 15 7 12 6 6 6 6 6 6 8 15 3.0 .63 .52 .42 .33 .28 .29 .25 .23 2.0 .51 .34 3.2 .58 3.0 .91 .22 .40 139 e4.9 e.95 3.0 .69 .63 .72 .82 .63 .54 1.3 4.2 TOTAL 1431 472.06 2194 205.82 1762 174.49 e Estimated 308 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA,PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1992 TO SEPTEMBER 1993 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) AUGUST MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR 34 51 121 42 39 36 105 93 66 49 342 78 59 83 158 152 80 69 60 50 46 101 218 103 69 73 66 50 47 47 48 2635 21431 JULY 5 9 22 6 5 5 22 14 11 9 58 11 3 11 33 30 12 10 9 8 7 19 56 18 12 10 9 9 9 9 8 —— .46 1.8 10 .65 .57 .46 12 3.4 2.0 1.2 95 2.4 .46 6.0 24 17 2.6 2.0 1.5 1.1 .85 13 53 5.2 2.2 1.9 1.7 1.2 1.1 1.1 1.1 266.95 3710.17 MEAN DISCHARGE (CPS) 50 56 53 51 47 46 46 44 42 44 47 41 37 34 45 76 54 69 73 43 34 53 66 38 32 30 27 29 28 39 65 1439 8 8 8 7 7 7 7 6 6 6 6 6 5 5 7 13 8 27 12 5 4 8 11 5 4 4 3 3 3 5 9 1.1 1.2 1.1 1.0 .88 .84 .81 .75 .69 .71 .74 .62 .54 .48 1.1 3.1 1.2 27 3.1 .58 .36 2.0 2.1 .49 .33 .30 .26 .26 .24 .62 1.8 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) SEPTEMBER e32 8 el. 3 e50 10 el. 4 e45 e84 e45 ellO elOO e52 e49 e35 e38 e36 e35 e27 e60 e400 elOO e92 e30 e26 e24 e23 e28 e22 e52 e21 e40 e30 e46 e52 11 12 13 14 15 15 12 9 6 5 4 5 13 32 17 7 3 3 4 5 5 6 7 7 7 7 7 7 el. 4 e2.0 e2.1 e2.7 e4.2 e3.0 el. 6 e.98 e.63 e.48 e.34 e.40 el. 6 e!6 ell el. 8 .52 .26 .27 .29 .36 .41 .65 .64 .56 .66 .71 .92 56.30 1784 59.18 e Estimated RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED {TONS/DAY), WATER YEAR OCTOBER 1993 TO SEPTEMBER 1994 309 DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) OCTOBER e56 e38 e56 e40 e30 e44 63 38 34 34 34 42 30 26 24 74 69 41 50 53 38 125 83 48 36 39 43 49 32 28 25 25 6 7 7 5 9 14 5 4 4 4 6 4 3 3 14 12 7 8 8 6 46 27 7 6 5 8 10 4 3 3 el 6 e3. e2. el. e. el. 3. . • 4. 3. . 1. 1. 68 6. . • 1. 1. . 8 1 0 48 2 9 55 37 37 36 85 36 24 22 2 7 74 7 2 58 3 92 53 49 2 7 38 25 20 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) NOVEMBER 1422 123.89 24 23 21 21 20 20 22 44 57 36 29 25 40 93 130 103 74 129 67 51 42 40 37 39 33 80 44 32 42 61 1479 3 3 2 2 2 2 3 8 10 6 3 3 6 16 25 20 13 45 11 6 5 5 5 5 5 14 7 5 4 11 .18 .16 .14 .13 .12 .11 .16 1.2 1.6 .62 .25 .20 .78 4.7 9.6 6.5 2.7 38 2.2 .88 .60 .53 .49 .51 .44 3.7 .87 .42 .49 2.3 DECEMBER 80.58 37 32 28 36 43 35 25 23 23 e23 e21 20 20 20 18 17 17 21 76 119 56 27 23 22 21 23 58 60 27 30 31 1032 6 4 4 5 6 6 4 3 3 3 3 2 2 2 2 2 2 2 14 30 9 4 3 3 2 2 10 10 3 5 4 .56 .37 .27 .57 .76 .56 .26 .21 .19 e.18 e.15 .13 .12 .11 .10 .09 .09 .13 5.1 20 2.0 .27 .20 .17 .14 .18 1.8 1.8 .25 .39 .36 37.51 Estimated 310 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA,PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1993 TO SEPTEMBER 1994 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) JANUARY MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) FEBRUARY MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MARCH 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL 57 73 39 38 38 29 32 31 31 34 66 41 38 44 28 28 38 27 27 36 35 26 e22 e!8 e!9 e!7 e!7 e44 e72 e70 e!8 1133 9 13 5 5 6 4 4 4 3 5 11 5 5 7 4 3 6 4 3 5 5 4 4 4 3 3 3 6 11 10 2 1.9 2.9 .55 .54 .67 .32 .39 .31 .28 .52 2.0 .58 .64 .88 .27 .26 .60 .26 .24 .53 .46 .28 e.22 e.17 e.17 e.15 e.14 e.76 e2.6 e2.5 e.ll 30 35 24 42 36 27 30 26 22 21 21 21 20 34 25 42 24 57 509 228 54 80 39 32 31 34 27 23 5 6 3 6 5 3 5 3 2 1 1 1 2 4 4 6 4 9 125 35 8 15 4 2 2 3 4 4 .43 .63 .20 1.0 .48 .25 .41 .22 .10 .06 .07 .08 .09 .53 .27 .80 .23 2.6 446 36 1.2 6.1 .46 .19 .16 .35 .32 .23 22.20 1594 499.46 24 83 37 23 21 20 19 18 17 18 20 56 20 16 15 14 14 14 13 14 15 14 14 14 14 14 19 22 26 20 15 663 4 14 7 4 3 2 1 1 1 1 2 9 4 3 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 .25 3.6 .77 .26 .15 .10 .07 .05 .05 .06 .09 1.8 .22 .14 .09 .08 .07 .06 .05 .05 .05 .04 .04 .04 .04 .04 .05 .06 .07 .05 .04 8.53 e Estimated RIO MAMBYES BASIN 50065500 RIO MAMBYES NEAR SABANA,PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1993 TO SEPTEMBER 1994 311 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 17 15 14 13 13 17 24 20 14 39 85 37 18 24 37 65 73 46 21 18 17 15 14 14 14 13 15 15 14 14 ___ APRIL 1 1 1 1 1 2 3 3 2 7 22 5 1 3 6 24 17 8 7 8 7 6 5 4 4 3 3 2 2 2 ___ .05 .04 .04 .03 .03 .09 .32 .15 .08 1.1 11 .61 .06 .21 .99 16 3.8 1.2 .38 .38 .31 .25 .19 .17 .14 .12 .12 .10 .08 .08 ___ MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MAY JUNE 14 13 13 16 49 26 16 24 56 97 44 30 21 132 56 69 37 24 20 19 18 18 17 17 19 17 16 16 21 17 19 2 2 2 2 9 4 2 3 11 22 7 3 2 42 10 17 9 7 6 5 4 3 3 3 3 3 2 2 2 2 2 .07 .07 .07 .09 2.9 .27 .10 .22 4.6 9.0 .92 .24 .14 51 1.6 7.4 .91 .45 .31 .23 .18 .14 .13 .12 .13 .11 .10 .10 .13 .10 .10 31 19 28 26 44 63 23 20 18 17 26 21 20 15 24 19 111 54 25 19 16 15 14 15 19 123 23 18 35 64 5 3 4 5 7 11 1 1 1 2 3 3 3 2 3 3 41 16 14 11 8 6 4 3 2 31 6 3 5 10 .46 .15 o33 .33 1.0 3.4 .08 .06 .07 .08 .27 .20 .15 .09 .21 .14 30 2.3 .93 .56 .36 .24 .17 .13 .13 28 .36 .15 .68 3.4 TOTAL 755 38.12 971 81.93 965 74.43 312 RIO MAMBYES BASIN 50065500 RIO MAMBYES NEAR SABANA,PR--Continu«d SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1993 TO SEPTEMBER 1994 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) JULY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 23 18 23 16 16 30 21 24 16 13 13 13 11 11 9.6 9.0 10 119 19 13 12 11 10 10 e8.8 e!2 e!5 e!9 e30 e!6 e58 3 3 3 2 2 4 3 3 2 2 2 2 2 1 1 1 1 45 7 5 4 3 2 2 1 2 6 12 8 3 11 TOTAL £29.4 --- YEAR e 12099.2 Estimated .22 .13 .18 .09 .08 .46 .16 .16 .10 .08 .07 .06 .05 .04 .03 .03 .03 40 .36 .19 .12 .08 .06 .04 .03 .07 .22 .67 .76 .11 2.9 47.58 1075.01 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) AUGUST e24 e!5 ell ell e9.2 e30 e!4 ell e9.6 e22 ell e8.5 e7.5 e!2 ell elO elO e49 e45 e30 e20 e23 e43 e37 e39 e20 e23 e27 e20 e!5 e!4 4 2 1 1 1 5 2 2 1 3 2 1 1 1 2 1 1 20 14 8 5 3 12 7 7 2 3 4 2 2 2 e.30 e.06 e.03 e.03 e.02 e.81 e.09 e.05 e.03 e.20 e.05 e.03 e.02 e.05 e.05 e.04 e.03 ell e2.4 e.62 e.27 e.21 e4.4 e.71 e.99 e.13 e.18 e.29 e.ll e.07 .06 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) SEPTEMBER el4 el5 el3 e!3 e!2 e46 e50 e40 e22 e65 e29 e!7 e!6 e!9 e25 e29 e20 e21 e29 e!39 e30 e21 e21 e!9 e20 e!7 e!5 e!5 e!4 e20 1 1 1 1 1 8 17 7 3 11 4 2 2 2 4 4 3 2 3 27 6 3 2 2 2 2 2 2 1 1 e.05 e.05 e.04 e.04 e.04 el. 4 e8.8 e.97 e.18 e2.7 e.33 e.09 e.09 e.10 e.30 e.32 e.16 e.ll e.48 e20 e.47 e.16 e.ll e.ll e.ll e.09 e.09 e.07 e.05 e.06 --- 631.8 23.22 824 37.56 RIO MAMEYES BASIN 313 50065500 RIO MAMS YES NEAR SABAHA,PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) OCTOBER 1 2 3 4 5 6 7 B 9 10 11 12 13 14 15 16 17 IB 19 20 21 22 23 24 25 26 27 26 29 30 31 e!7 e!3 el3 elO 10 10 11 12 22 70 31 20 17 20 14 13 14 15 25 151 33 73 97 79 36 24 21 19 IB 19 IB 1 1 1 1 1 2 4 2 3 13 5 2 5 10 B 4 2 1 4 56 5 13 20 12 6 5 5 2 1 4 12 e.05 e.04 e.03 e.03 .03 .07 .12 .07 .26 3.5 .46 .10 .22 .52 .33 .16 .OB .05 .36 56 .79 2.7 B.3 3.1 .54 .35 .27 .13 .06 .21 .59 NOVEMBER IB 15 15 16 15 97 134 12 B 120 160 B6 3B 29 24 22 20 31 21 19 23 B3 55 33 21 51 4B 75 32 77 119 10 7 4 4 4 32 32 46 32 23 16 10 9 B 7 6 7 5 4 4 17 9 4 2 10 7 19 6 14 27 .49 .27 .17 .17 .16 24 42 20 29 21 4.9 1.0 .66 .51 .39 .31 .65 .27 .20 .24 5.4 1.5 .39 .14 1.7 1.0 6.3 .52 5.1 10 DECEMBER 12 B 297 100 113 67 53 40 37 45 30 33 24 31 2B 24 22 3B 25 22 20 19 23 26 29 40 27 26 40 2B 26 25 31 53 17 25 17 22 15 9 B 6 4 3 4 4 3 2 6 4 3 3 2 3 3 5 6 4 4 6 2 2 2 24 49 4.9 13 3.0 3.1 1.7 .94 1.1 .45 .36 .22 .34 .32 .17 .12 .66 .26 .19 .14 .11 .19 .22 .52 .71 .28 .26 .70 .18 .14 .13 TOTAL 945 79.52 1625 17B.46 14B6 107.45 e Estimated 314 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA,PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAY MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL 33 38 32 28 25 23 22 21 39 27 34 87 51 50 49 37 29 26 24 23 23 22 21 22 19 127 146 157 45 33 28 1341 4 5 3 4 3 2 9 9 7 6 5 16 7 7 8 6 3 2 2 2 2 2 3 3 2 27 38 45 8 6 5 .40 .61 .27 .30 .19 .16 .52 .53 .76 .48 .48 5.7 1.1 1.0 1.0 .57 .25 .15 .13 .13 .12 .13 .15 .17 .12 14 34 24 .99 .57 .40 89.38 24 24 22 21 20 20 23 24 20 19 29 21 19 18 32 53 40 35 49 40 69 38 28 26 203 54 234 219 1424 4 4 3 1 2 3 3 3 1 1 5 4 5 6 4 9 5 3 8 6 13 4 3 2 50 7 54 54 .29 .24 .18 .07 .10 .18 .20 .17 .07 .05 .53 .25 .26 .28 .52 1.7 .64 .35 1.0 .67 4.3 .43 .25 .16 77 1.3 66 60 217.19 52 37 31 47 46 29 92 47 e!24 e49 e32 e39 e73 e50 e35 31 27 26 24 23 22 22 20 20 20 19 19 18 17 17 17 1125 5 6 16 21 10 8 21 7 34 9 5 6 11 6 2 2 3 2 2 1 1 1 1 1 1 1 1 1 1 1 1 .71 .53 1.4 2.6 1.4 .60 9.5 .99 «25 el. 3 e.48 e.69 e3.7 e.98 e.18 .13 .19 .17 .12 .08 .06 .08 .08 .05 .05 .05 .05 .05 .05 .05 .05 51.37 e Estimated RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA,PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 315 MEAN MEAN CONCEN- SEDIMENT MEAN DISCHARGE TRATION DISCHARGE DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) (CPS) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 17 16 15 14 20 16 15 14 14 13 14 32 19 17 26 55 24 19 18 17 17 17 17 16 16 15 15 15 14 14 APRIL 1 1 1 1 2 2 2 3 4 5 5 6 3 2 4 11 4 2 2 1 1 2 2 6 14 9 3 1 1 2 ___ .05 .04 .04 .04 .13 .10 .10 .11 .14 .17 .20 .59 .14 .11 .34 2.1 .23 .11 .08 .05 .05 .07 .10 .24 .61 .38 .14 .05 .05 .08 ___ 13 12 11 31 53 41 28 36 26 17 13 19 38 22 254 120 27 19 23 34 46 20 15 14 19 36 117 70 175 119 86 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) MAY TOTAL 551 6.64 1554 3 5 5 7 10 6 4 5 3 1 1 2 6 4 77 26 2 1 5 5 8 3 2 2 3 5 28 13 38 22 15 .__ .11 .15 .15 1.0 2.5 .78 .32 .52 .22 .05 .04 .10 1.0 .25 293 17 .19 .05 .36 .72 1.3 .17 .09 .08 .15 .78 21 2.4 28 7.8 3.6 383.88 MEAN DISCHARGE (CPS) 61 90 139 55 42 81 61 42 37 36 198 153 107 70 81 88 56 44 40 47 48 38 33 34 37 30 28 23 20 22 1841 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) JUNE 10 16 28 9 5 14 8 7 6 5 39 30 23 7 9 19 21 20 18 47 44 3 3 4 6 9 13 7 2 5 1.6 4.0 12 1.3 .53 3.1 1.3 .75 .56 .51 42 21 8.7 1.5 1.9 5.0 3.2 2.3 1.9 7.0 6.0 .37 .26 .40 .63 .76 .97 .41 .11 .31 130.37 316 RIO MAMBYES BASIN 50065500 RIO MAMBYES NEAR SABANA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR 19 19 29 50 59 50 26 26 24 24 20 26 35 22 33 34 27 37 25 24 44 84 43 33 42 42 171 107 58 57 37 1327 16758 JULY 6 4 3 7 14 10 4 21 17 10 4 3 5 3 5 5 4 6 4 3 8 18 12 10 7 5 37 24 9 10 6 —— MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) AUGUST .30 .18 .33 1.2 3.3 1.9 .29 1.5 1.0 .66 .22 .23 .55 .20 .65 .46 .31 .62 .28 .20 3.2 5.5 1.3 .91 .81 .52 28 11 1.5 1.9 .59 69.61 1642.05 53 70 107 51 42 46 79 70 53 43 41 51 42 29 23 23 49 104 119 53 63 60 59 53 44 36 33 35 60 62 48 1701 8 11 34 26 12 7 27 13 8 7 8 18 15 12 9 5 6 29 33 18 14 12 8 10 5 5 6 8 13 15 8 —— 1.6 2.3 11 3.6 1.3 .90 9.7 2.6 1.2 .76 1.1 2.4 1.7 .99 .53 .33 .90 11 28 2.6 2.5 2.3 1.5 1.5 .58 .47 .55 .78 4.4 4.5 1.0 104.59 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) SEPTEMBER 45 39 39 45 96 193 49 72 42 42 61 46 38 31 36 326 99 57 45 46 59 44 37 34 31 31 32 35 54 34 --- 1838 4 3 2 2 11 53 8 13 7 6 6 4 2 2 3 78 26 12 3 1 8 10 8 7 6 5 5 3 75 39 --- —— .44 .29 .26 .27 5.7 75 1.1 3.6 .77 .73 .98 .50 .24 .17 .56 103 7.0 2.0 .38 .12 1.5 1.2 .83 .66 .51 .43 .44 .31 11 3.6 --- 223.59 317 RIO MAMBYES BASIN 50065500 RIO MAMEYES NR SABANA, PR--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OP SUSPENDED SEDIMENT DATE DEC 1994 01... MAY 1995 15.. . 15.. . SEP 16.. . TIME 1950 1504 2216 0526 DIS- CHARGE, INST. CUBIC FEET PER SECOND 651 884 2202 1007 SEDI- MENT, SUS- PENDED (MG/L) 276 302 552 162 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 485 721 3282 440 SED. SUSP. PALL DIAM. PERCENT FINER THAN .002 MM 39 35 26 45 SED. SUSP. PALL DIAM. PERCENT FINER THAN .004 MM 46 42 30 51 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 55 51 34 55 DATE DEC 1994 01.. . MAY 1995 15... 15.. . SEP 16.. . SED. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 68 62 46 64 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 77 69 51 71 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 84 75 58 74 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 95 93 79 92 SED. SED. SED. SUSP. SUSP. SUSP. SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. PERCENT PERCENT PERCENT FINER FINER FINER THAN THAN THAN .250 MM .500 MM 1.00 MM 98 99 94 98 99 99.6 98 98 99.7 99.9 99 99 318 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SAB ANA, PR—Continued HATER QUALITY DATA, HATER YEAR OCTOBER 1993 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OP SUSPENDED SEDIMENT DATE AUG 1994 23.. . SEP 07.. . 07.. . 07.. . 20. . . 20.. . OCT 20.. . NOV 27... 30.. . DEC 01.. . 02... 02. .. 02. .. 02.. . 02. . . 02.. . 02. . . JAN 1995 26.. . MAR 09.. . HAY 29... JDN 11.. . JUL 28.. . SEP 16.. . 16., . 16.. . 16.. . 16.. . 16.. . TIME 1955 2045 2115 2145 1200 1331 0940 1325 1420 2025 0325 0345 0405 0543 0613 0643 1455 1006 1756 1440 1615 162S 0610 0615 0725 0740 0800 OS02 STREAM- PLOW, INSTAN- TANEOUS (CPS) 265 319 287 219 313 244 208 79.0 225 479 600 576 453 555 547 454 440 182 390 118 880 285 925 707 893 1060 701 700 SEDI- MENT, SUS- PENDED (MG/L) 104 154 138 151 52 37 49 35 45 159 93 125 423 44 65 52 56 67 120 7 144 84 90 83 60 71 74 76 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 74 132 107 89 44 24 28 7.5 27 206 151 194 517 66 96 64 66 33 126 2.2 342 65 225 158 145 203 140 144 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 89 92 88 88 91 83 96 91 93 84 84 89 98 77 84 75 83 94 78 88 65 79 89 83 82 85 86 77 RIO SABANA BASIN 50067000 RIO SABANA AT SABANA, PR LOCATION.--Lat 18°19'52", long 65°43'52", Hydrologic Unit 21010005, on right bank along Highway 988, 0.3 mi (0.5 km) north of junction of Highways 988 and 983 in Sabana, and 3.3 mi (5.3 km) south of Lu<juillo. DRAINAGE AREA.--3.96 mi a (10.26 km 1 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1979 to current year. GAGE.—Water-stage recorder and crest-stage gage. Elevation of gage is 260 ft (80 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. 319 DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT JAN FEB APR AUG 1 3.7 3.9 2 3.0 2.9 3 3.0 2.9 4 2.7 3.0 5 2.7 3.8 6 2.9 87 7 3.0 144 8 3.7 82 9 6.6 95 10 57 207 11 8.3 69 12 3.1 17 13 2.8 9.2 14 2.9 6.6 15 2.8 5.4 16 2.8 4.9 17 3.1 4.9 18 4.8 4.3 19 3.6 4.2 20 141 5.2 21 14 33 22 100 19 23 133 13 24 101 7.2 25 19 16 26 8.3 22 27 5.5 50 28 4.7 12 29 3.9 37 30 3.3 89 31 4.5 —— TOTAL 660.7 1060.4 MEAN 21.3 35.3 MAX 141 207 MIN 2.7 2.9 AC-FT 1310 2100 CFSH 5.38 8.93 IN. 6.21 9.96 STATISTICS OF MONTHLY MEAN MEAN 21.3 31.4 MAX 66.4 79.7 (WY) 1986 1988 MIN 6.48 8.15 (WY) 1983 1981 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 41 316 65 87 31 22 18 16 19 13 15 12 13 21 13 12 19 11 9.2 8.4 7.8 9.3 12 36 37 12 9.4 13 7.6 6.6 6.0 918.3 29.6 316 6.0 1820 7.48 8.63 DATA 24.6 64.1 1982 3.92 1990 7.9 11 6.7 6.0 5.9 5.3 4.9 4.7 7.8 5.3 5.0 7.9 6.6 5.4 4.4 4.1 3.6 3.6 3.2 3.1 3.3 2.9 3.2 4.1 3.2 62 49 100 11 6.4 5.2 362.7 11.7 100 2.9 719 2.95 3.41 FOR WATER 12.8 33.0 1992 6.12 1986 4.4 4.1 3.6 3.5 3.3 3.0 3.5 3.5 3.1 2.9 2.9 2.7 2.4 2.6 3.3 7.7 6.5 5.5 5.7 4.6 10 5.3 3.0 2.6 96 17 89 131 ___ ___ --- 432.7 15.5 131 2.4 858 3.90 4.06 YEARS 1980 12.3 22.2 1988 2.94 1983 15 8.2 6.0 8.5 8.0 5.3 96 14 60 17 7.1 6.4 45 15 7.5 6.1 5.7 5.0 .7 .8 .6 .1 .5 3.8 3.8 3.5 3.5 3.3 2.9 3.0 2.7 385.0 12.4 96 2.7 764 3.14 3.62 - 1995 11.6 36.0 1987 2.71 1994 FOR 1994 CALENDAR YEAR 4440. 12. 316 1. 1. 8810 3. 41. 19 3. 1. 8 2 Dec 2 1 Jun 15 3 Jun 10 07 72 3 5 2.6 2.6 2.8 2.7 3.3 3.2 2.9 2.6 3.1 3.0 2.6 4.6 2.8 2.4 8.9 18 4.0 2.9 2.5 2.4 2.4 2.5 2.4 2.4 3.2 2.6 2.7 2.6 2.5 2.6 —— 105.8 3.53 18 2.4 210 .89 .99 2.6 2.5 2.5 2.7 3.2 3.5 8.2 5.1 4.4 2.9 2.8 3.2 117 13 211 78 8.8 5.6 24 13 24 10 7.9 7.0 6.8 7.0 40 31 83 165 48 943.7 30.4 211 2.5 1870 7.69 8.87 14 41 58 13 8.8 21 16 7.6 6.2 5.2 45 150 74 21 18 22 13 9.2 8.3 11 12 8.9 7.1 6.5 6.4 6.8 6.2 5.7 5.7 12—— 639.6 21.3 150 5.2 1270 5.38 6.01 6.8 5.4 6.0 24 11 24 13 13 9.0 8.5 8.7 11 11 10 13 13 12 18 15 15 16 29 19 18 18 18 167 53 27 47 28 687.4 22.2 167 5.4 1360 5.60 6.46 24 30 55 23 20 24 96 39 28 25 22 19 18 19 19 20 26 156 119 54 78 61 37 24 22 20 20 20 32 56 30 1236 39.9 156 18 2450 10.1 11.61 20 20 19 20 130 219 39 36 27 24 33 29 25 23 28 553 384 e!20 e78 e66 e76 e42 e29 e23 e!9 21 20 21 22 19 --- 2185 72.8 553 19 4330 18.4 20.53 , BY WATER YEAR (WY) 11.7 33.5 1990 2.20 1984 FOR 1995 9617 26 553 2 2 1810 12 2 19080 6 90 71 9 2 32.5 63.9 1982 4.65 1994 WATER YEAR .3 .3 Sep 16 .4 Feb 13 .5 Apr 18 Nov 7 . 62 Nov 7 .1 Feb 12 .65 .34 .2 .9 20.7 50.6 1987 4.70 1985 15.5 31.3 1989 5.84 1986 WATER 19 28 7 887 1 9600 19 14040 4 66 37 8 2 17.5 39.9 1995 3.09 1994 YEARS 1980 .4 .2 .85 Sep .96 Apr .0 Apr Jan .74 Jan . 8 6 Apr .89 .48 .4 .6 20.1 72.8 1995 7.23 1987 - 1995 1988 1994 18 1989 10 1983 6 1983 5 1992 5 1992 17 1983 e Estimated 320 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR LOCATION.--Lat 18°17'56", long 65 0 41'42», Hydrologic Unit 21010005, on left bank off Highway 976, 0.1 mi (0.2 km) upstream from Highway 977 bridge, 0.3 mi (0.5 km) downstream from Quebrada Penon, 1.1 mi (1.8 km) northeast of Colonia Parafso, and 3.3 mi (5.3 km) southwest of Fajardo. DRAINAGE AREA.--14.9 mi 1 (38.6 km 1 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1960-61 (occasional low and peak-flow measurements only). March 1961 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 137.60 ft (41.940 m) above mean sea level. Due to flood damage, gage datum has had changes as follows: Mar. 24, 1961 to Hay 5, 1969, 138.95 ft (42.352 m) ; Hay 6, 1969 to Mar. 16, 1972, 135.05 ft (41.163 m); Har. 17, 1972 to Mar 25, 1975, 138.60 ft (42.245 m). REMARKS.--Records fair. Low flow affected by diversions for water supply about 400 m upstream from gaging station (estimated mean daily discharges is 9.0 ft'/s (0.255 mVs). Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DEC FEB APR AUG SEP 1 7.1 10 2 6.3 9.2 3 5.8 8.7 4 6.2 8.8 5 7.2 9.2 6 8.1 101 7 7.7 224 8 5.5 338 9 13 234 10 118 569 11 21 233 12 11 73 13 9.2 36 14 8.5 22 15 8.7 16 16 6.4 14 17 4.9 39 18 13 17 19 62 20 20 136 16 21 28 105 22 105 104 23 162 49 24 144 57 25 37 151 26 19 78 27 14 211 28 12 82 29 11 174 30 10 264 31 11 —— TOTAL 1018.6 3272.9 MEAN 32.9 109 MAX 162 569 HIN 4.9 8.7 AC-FT 2020 6490 CFSH 2.21 7.32 IN. 2.54 8.17 STATISTICS OF MONTHLY MEAN MEAN 93.1 104 MAX 260 295 (WY) 1971 1975 HIN 19.1 26.0 (WY) 1969 1994 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL HEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 217 946 305 270 170 113 79 58 64 40 44 33 59 48 35 27 29 24 21 20 19 25 62 69 159 39 22 33 16 12 11 3069 99.0 946 11 6090 6.64 7.66 DATA 80.2 237 1976 14.9 1990 FOR 12 27 12 11 12 11 9.2 9.0 18 11 15 23 39 23 14 13 8.7 7.5 7.3 6.6 6.2 5.9 6.0 6.0 5.9 231 159 253 47 27 20 1056.3 34.1 253 5.9 2100 2.29 2.64 FOR WATER 44.2 101 1969 15.4 1977 17 16 13 12 10 9.8 9.9 14 9.8 8.5 15 11 8.2 7.5 17 29 23 15 15 24 47 17 8.8 7.4 221 64 354 435 ___ —— 1438.9 51.4 435 7.4 2850 3.45 3.59 YEARS 1961 37.4 80.4 1982 10.8 1983 91 40 27 52 55 22 35 29 195 62 26 45 160 82 28 21 17 15 14 12 12 11 11 10 11 9.7 10 9.7 8.4 8.0 7.2 1136.0 36.6 195 7.2 2250 2.46 2.84 - 1995 35.1 109 1987 9.70 1977 1994 CALENDAR YEAR 11762. 32. 946 2. 3 . 23330 2. 29. 77 9. 4. 6 2 Dec 2 7 Aug 16 2 Jul 21 16 37 6 2 • 7.2 6.8 6.6 7.0 8.1 8.8 6.0 5.2 14 8.0 6.4 37 9.4 6.5 11 32 11 7.7 6.0 5.4 5.2 5.0 4.9 4.7 5.6 4.5 4.3 4.2 3.8 4.5 —— 256.8 8.56 37 3.8 509 .57 .64 4.9 4.9 4.3 6.6 6.8 14 16 27 56 17 12 9.8 33 24 191 192 24 13 16 17 18 9.5 6.9 6.2 11 15 144 87 327 521 209 2043.9 65.9 521 4.3 4050 4.42 5.10 91 122 173 67 40 86 60 36 31 22 262 274 123 64 87 66 110 38 27 33 27 23 19 16 15 16 14 13 11 32 --- 1998 66.6 274 11 3960 4.47 4.99 17 11 23 41 46 48 19 17 14 12 42 56 43 25 58 37 23 56 26 32 34 83 37 23 25 45 387 137 72 70 45 1604 51.7 387 11 3180 3.47 4.00 36 46 152 40 28 45 104 126 60 36 33 24 21 18 17 21 46 284 156 45 70 24 21 21 19 18 22 20 23 30 26 1632 52.6 284 17 3240 3.53 4.07 21 22 22 20 190 403 91 85 49 37 41 32 29 24 63 915 754 241 150 127 144 81 55 43 36 34 33 33 69 28 --- 3872 129 915 20 7680 8.66 9.67 , BY WATER YEAR (WY) 44.0 129 1963 4.02 1984 FOR 1995 22398. 61. 946 3. 4. 4710 8. 44430 4. 55. 159 23 6. 92.9 399 1979 17.7 1973 WATER YEAR 4 4 Dec 2 8 Apr 29 4 Apr 27 Nov 10 41 Nov 10 12 92 9 59. 9 166 1962 10.0 1985 50.3 132 1969 11.4 1994 WATER 65 140 19 8800 1 1 23500 20 47610 4 59 127 32 10 56.4 159 1979 9.70 1994 YEARS 1961 - .7 .0 Sep 18 . 0 Hay 6 .5 Apr 18 Sep 18 .00 Sep 18 .86 Hay 3 .41 .93 86.2 421 1989 18.9 1994 1995 1979 1994 1989 1984 1984 1989 1989 1984 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.—Water years 1960 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 321 DATE OCT 1994 31. .. DEC 20. .. FEB 1995 10. .. APR 19. .. JUN 21. .. AUG 21. .. DATE OCT 1994 31. .. DEC 20. .. FEB 1995 10. .. APR 19. .. JUN 21. .. AUG 21. .. DATE OCT 1994 31. .. DEC 20. .. FEB 1995 10. .. APR 19. .. JUN 21. .. AUG 21. . . TIME 0940 0815 0830 0945 0815 0855 HARD- NESS TOTAL (HG/L AS CACO3) 34 -- 34 36 -- 33 SILICA, DIS- SOLVED (HG/L AS SI02) 25 -- -- 25 — 22 DIS- CHARGE, INST. CUBIC FEET PER SECOND 11 18 8.8 5.6 28 42 CALCIUM DIS- SOLVED (HG/L AS CA) 7.8 -- 7.7 8.1 -- 7.4 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 110 _- -- 95 -- 75 SPE- CIFIC CON- DUCT- ANCE (US /CM) 129 129 198 130 116 102 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 3.6 __ 3.7 3.9 __ 3.5 SOLIDS, DIS- SOLVED (TONS PER DAY) 3.20 __ -- 1.43 — 8.51 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.1 6.7 6.9 6.9 6.8 6.5 SODIUM, DIS- SOLVED (MG/L AS NA) 11 __ 13 12 __ 10 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 1 <1 <1 1 2 128 TEMPER- ATURE WATER (DEG C) 25.5 23.5 23.0 25.0 24.5 25.5 SODIUM AD- SORP- TION RATIO 0.8 — 1 0.9 __ 0.8 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 <0.20 <0.20 <0.20 <0.20 0.18 TUR- BID- ITY (NTU) 0.80 0.80 0.70 0.50 1.2 13 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 1.3 __ 1.4 1.1 __ 1.6 PHOS- PHORUS TOTAL (MG/L AS P) <0.010 <0.010 0.020 <0.010 0.020 0.190 OXYGEN, DIS- SOLVED (MG/L) 7.5 6.4 5.4 3.4 7.6 5.6 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 70 41 43 46 36 28 ARSENIC TOTAL (UG/L AS AS) <1 — -- <1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 91 74 62 40 90 68 SULFIDE TOTAL (MG/L AS S) <0.5 __ __ <0.5 __ -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 __ -- <100 — — OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 <10 13 <10 <10 15 SULFATE DIS- SOLVED (MG/L AS SO4) 5.2 __ 3.4 3.7 __ 3.8 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 20 — -- 20 -- -- COLI- FORM, FECAL, 0.45 UM-MP (COLS./ 100 ML) K170 K170 K20 K54 170 K1900 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 14 __ 13 14 __ 10 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 _- -- <1 — -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 2100 K54 K160 210 250 K2100 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 __ <0.10 <0.10 __ <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 — -- <1 -- -- K = non-ideal count 322 RIO FAJARDO BASIN 50071000 RIO PAJARDO NEAR PAJARDO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 COPPER, TOTAL RECOV- ERABLE (OG/L AS CO) IRON, TOTAL RECOV- ERABLE (UG/L AS FE) LEAD, TOTAL RECOV- ERABLE (OG/L AS PB) MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) SELE- NIUM, TOTAL (UG/L AS SE) SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) CYANIDE TOTAL (MG/L AS CN) PHENOLS TOTAL (UG/L) METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) OCT 1994 31. .. DEC 20... FEB 1995 10. .. APR 19... JUN 21. . . AUG 21. .. 90 120 10 10 <0.10 <0.10 <0.010 <0.010 <0.02 <0.02 PESTICIDE ANALYSES DATE JUN 1995 21.. . PCB, TOTAL (OG/L) ALDRIN, TOTAL (UG/L) CHLOR- DANE, TECH- NICAL TOTAL (UG/L) P,P'- DDD UNFILT RECOVER (UG/L) DDE, TOTAL (OG/L) P,P'- DDT UNFILT RECOVER (UG/L) DI- AZINON, TOTAL (UG/L) DI- ELDRIN TOTAL (UG/L) ENDO- SULFAN, I TOTAL (OG/L) 0815 <0.100 <0.010 <0.100 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 ENDRIN WATER UNFLTRD ETHION, DATE REC TOTAL (UG/L) (UG/L) JUN 1995 21... HEPTA- METH- METHYL HEPTA- CHLOR MALA- OXY- PARA- CHLOR, EPOXIDE LINDANE THION, CHLOR, THION, MIREX, TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL (UG/L) (UG/L) (OG/L) (UG/L) (OG/L) (UG/L) (UG/L) <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 JUN 1995 21... PARA- PCNS THION, UNFILT TOTAL RECOVER (UG/L) (UG/L) PER- THANB TOTAL (UG/L) TOX- APHENE, TOTAL (UG/L) <0.010 <0.100 <0.100 <1.00 TOTAL TRI- THION (OG/L) 2,4-D, TOTAL (UG/L) 2,4,5-T TOTAL (UG/L) 2, 4-DP TOTAL (UG/L) SILVEX, TOTAL (UG/L) <0.010 <0.010 <0.010 <0.010 <0.010 RIO FAJARDO BASIN 50072500 RIO FAJARDO BELOW FAJARDO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°19'35", long 65°36'47 M , 1.2 mi (1.9 km) southwest of Playa de Fajardo, and 0.5 mi (0.6 km) east of Fajardo plaza. DRAINAGE AREA.--23.4 mi> (60.6 km 1 ). PERIOD OF RECORD.—Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 323 DATE OCT 1994 31... DEC 20. .. FEE 1995 10. .. APR 19. .. JUN 21. .. AUG 21. .. DATE OCT 1994 31. .. DEC 20. .. FEE 1995 10. .. APR 19. .. JUN 21. .. AUG 21. . . DATE OCT 1994 31. .. DEC 20. .. FEE 1995 10... APR 19. . . JUN 21. .. AUG 21. . . TIME 1100 0945 0955 1155 0935 1020 HARD- NESS TOTAL (MG/L AS CACO3) 39 -- -- 41 -- 30 SILICA, DIS- SOLVED (MG/L AS SIO2) 23 __ -- 22 -- 22 DIS- CHARGE, INST. CUBIC FEET PER SECOND 14 26 15 e.o 42 46 CALCIUM DIS- SOLVED (MG/L AS CA) 8.6 -- -- 9.1 -- 6.6 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 131 -_ -- 101 -- ei SPE- CIFIC CON- DUCT- ANCE (US /CM) 146 152 202 160 134 lie MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 4.3 -- -- 4.5 -- 3.4 SOLIDS, DIS- SOLVED (TONS PER DAY) 5.03 __ -- 2.16 -- 10.5 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.2 6.7 7.0 7.5 6.6 6.5 SODIUM, DIS- SOLVED (MG/L AS NA) 13 -- -- 14 -- 10 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 4 <1 3 <1 5 3 TEMPER- ATURE WATER (DEG C) 27.0 25.0 27.0 27.0 25.5 26.5 SODIUM AD- SORP- TION RATIO 0.9 -- -- 0.9 __ 0.8 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 <0.20 <0.20 <0.20 <0.20 0.26 TUR- BID- ITY (NTU) 1.5 1.7 1.1 2.6 1.4 6.5 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 0.90 __ -_ 1.1 __ 1.1 PHOS- PHORUS TOTAL (MG/L AS P) <0.010 0.020 <0.010 <0.010 0.020 0.030 OXYGEN, DIS- SOLVED (MG/L) 6.0 2.0 5.6 5.6 6.3 7.6 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 96 49 43 46 36 36 ARSENIC TOTAL (UG/L AS AS) <1 -_ -- <1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 75 24 69 71 76 96 SULFIDE TOTAL (MG/L AS S) <0.5 __ -- <0.5 __ ~~ BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 11 <10 22 <10 <10 <10 SULFATE DIS- SOLVED (MG/L AS SO4) 6.6 -- -- 4.9 -- 4.2 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 40 -- -- 30 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 350 240 K45 120 200 2400 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 16 _- -- 17 -- 12 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 3400 550 K30 100 60 320 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 -- -- <0.10 -- <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 -- -- K = non-ideal count 324 RIO PAJARDO BASIN 50072500 RIO PAJARDO BELOW PAJARDO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) OCT 1994 31. . . DEC 20. .. FEB 1995 10. .. APR 19. .. JUN 21. .. AUG 21. . . 20 160 780 <1 60 <0.10 <0.010 <0.010 (MG/L) 0.02 <0.02 RIO BLANCO BASIN 50074950 QUEBRADA GUABA NEAR NAGUABO, PR LOCATION.—Lat 18°17'02", long 65°47'20", Hydrologic Unit 21010005, on right bank, oft Highway 191 at El Yunque Caribbean National Forest, 4.8 mi (7.7 km) southeast of Campamento Eliza Colberg, 1.3 mi (2.1 km) southeast of Mt. Britton, 2.0 mi (3.2 km) northwest of Pico del Bate and 7.3 mi (11.7 km) southeast of Rio Grande Plaza. 325 DRAINAGE AREA.--0.05 mi 1 (0.13 km 1 ). WATER-DISCHARGE RECORDS PERIOD OP RECORD.--JUne 1992 to current year. GAGE.--Water-stage recorder. Elevation of gage is 2,100 ft (640 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 PEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT DEC JAN FEB APR MAY JUN SEP 1 .19 .13 2 .19 .11 3 .18 .10 4 .17 .11 5 .16 .10 6 .12 .53 7 .11 .74 8 .11 .46 9 .32 .58 10 .71 .83 11 .19 .22 12 .15 . 17 13 .26 .14 14 .23 .13 15 .19 . 13 16 .11 .12 17 .16 .42 18 .17 .20 19 e.40 .13 20 el. 4 .16 21 e.35 .33 22 .70 .27 23 1.0 .18 24 .92 .20 25 .36 .27 26 .21 .39 27 .20 .70 28 .16 .29 29 .15 .92 30 .15 .58 31 .13 TOTAL 9.85 9.64 MEAN .32 .32 MAX 1.4 .92 MIN .11 .10 AC-PT 20 19 CPSM 2.65 2.68 IN. 3.05 2.99 STATISTICS OP MONTHLY MEAN MEAN .33 .48 MAX .41 .76 (WY) 1994 1993 MIN .25 .32 (WY) 1993 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK PLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOPP (AC-FT) ANNUAL RUNOPP (CPSM) ANNUAL RUNOPP (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 1.1 1.7 .64 .87 .55 .35 .31 .25 .34 .26 .25 .23 .25 .22 .20 .24 .23 .22 .18 .18 .18 .17 .18 .17 .27 .23 .19 .21 .19 .19 .19 10.74 .35 1.7 .17 21 2.89 3.33 DATA .39 .61 1993 .22 1994 FOR .18 .25 .21 .19 .19 .19 .19 .18 .24 .27 .37 .60 .32 .28 .32 .23 .23 .20 .17 .16 .14 .13 .12 .12 .12 .63 1.4 .86 .28 .24 .24 9.25 .30 1.4 .12 18 2.49 2.87 .25 .22 .23 .22 .24 .23 .33 .25 .21 .22 .32 .24 .23 .24 .34 .33 .27 .25 .22 .16 .19 .11 .12 .11 1.7 .58 2.6 1.6 ___ ___ --- 12.01 .43 2.6 .11 24 3.57 3.72 FOR WATER YEARS 1992 .38 .55 1993 .28 1994 .45 .60 1994 .32 1993 .37 .33 .27 .32 .26 .22 .41 .27 .38 .25 .24 .40 .78 .58 .33 .30 .27 .25 .23 .22 .22 .22 .20 .20 .21 .21 .28 .24 .25 .26 .23 9.20 .30 .78 .20 IB 2.47 2.85 - 1995 .27 .30 1995 .23 1994 1994 CALENDAR YEAR 117.78 .32 6.1 .09 .12 234 2.69 36.51 .60 .22 .13 Feb 19 Apr 4 Mar 30 .22 .22 .22 .21 .18 .15 .13 .13 .14 .13 .11 .27 .14 .13 .17 .68 .26 .25 .28 .24 .23 .23 .23 .22 .22 .21 .21 .20 .20 .21 --- 6.42 .21 .68 .11 13 1.78 1.99 .22 .27 .21 .35 .34 .29 .24 .25 .26 .23 .21 .19 .18 .19 .71 .42 .24 .24 .30 .39 .33 .23 .21 .21 e.31 e.25 e.70 e.62 e.85 e.60 e.42 10.46 .34 .85 .18 21 2.81 3.24 .36 .55 .82 .30 .22 .42 .39 .24 .19 .29 .94 .51 .35 .35 .65 .41 .31 .29 .26 .32 .34 .23 .21 .22 .26 .25 .28 .29 .27 .25 --- 10.77 .36 .94 .19 21 2.99 3.34 .21 .20 .49 .51 .85 .60 .28 .21 .20 .16 .21 .18 .38 .19 .31 .40 .17 .27 .19 .28 .47 .46 .24 .19 .16 .28 1.3 .50 .33 .30 .23 10.75 .35 1.3 .16 21 2.89 3.33 .42 .32 .62 .25 .18 .22 .22 .69 .25 .19 .19 .14 .18 .17 .16 .20 .33 .60 .33 .26 .31 .26 .27 .28 .23 .21 .20 .19 .29 .41 .28 8.85 .29 .69 .14 18 2.38 2.74 .22 .20 e.16 e.15 el.O e2.5 e.35 1.4 .46 .20 .37 .27 e.21 e.14 e.39 3.2 .62 .39 .35 .51 .53 .45 .44 .42 .39 .40 .41 .43 .55 .36 --- 17.47 .58 3.2 .14 35 4.85 5.42 , BY WATER YEAR (WY) .29 .33 1994 .21 1995 POR 1995 125 3 42 9 249 2 38 .43 .61 1993 .33 1994 WATER YEAR .41 .34 .2 Sep 16 . 10 Nov 3 .12 Oct 30 Peb 25 .71 Peb 25 .86 .88 .62 .25 .15 .34 .36 1995 .32 1993 .59 1.18 1992 .22 1994 WATER 6 64 10 265 3 41 .32 .56 1992 .19 1993 YEARS 1992 .37 .43 .32 .1 Jul .09 Apr . 12 Mar May . 11 May .05 .41 .72 .26 .16 .41 .58 1995 .34 1993 - 1995 1993 1994 16 1992 4 1994 30 1994 1 1993 1 199' e Estimated 326 RIO BLAHCO BASIN 50075000 RIO ICACOS NEAR NAGUABO, PR LOCATION.--Lat 18°16'38", long 65°47'09", Rydrologic Unit 21010005, in Caribbean National Forest, at Highway 191, at El Yunque, 1.6 mi (2.6 km) upstream from confluence with Rio Cubuy, 2.8 mi (4.5 km) north of Florida, and 5.3 mi (8.5 km) northwest of Naguabo Plaza. DRAINAGE AREA.--1.26 mi 1 (3.26 km 1 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.—July 1945 to March 1953 (operated by Puerto Rico Water Resources Authority), annual maximum, water years 1953-62, annual low-flow measurements 1962-66, October 1979 to current year. GAGE.--Water-stage recorder, crest-stage gage and sharp-crested weir. Elevation of gage is 2,020 ft (616 m), from topographic map. REHARKS.--Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT DEC JAN APR JOL SEP 1 .6 4.6 2 .5 3.9 3 .5 3.5 4 .3 4.9 5 .0 4.0 6 3.7 29 7 3.5 34 8 3.8 39 9 7.9 42 10 26 56 11 6.4 15 12 5.2 8.3 13 11 6.7 14 6.3 5.9 15 4.4 5.5 16 3.8 4.5 17 3.7 19 18 3.8 6.2 19 17 4.7 20 88 4.5 21 13 19 22 29 14 23 40 5.8 24 34 3.9 25 9.3 11 26 5.4 12 27 4.5 25 28 4.3 8.4 29 4.0 37 30 4.1 35 31 3.8 --- TOTAL 367.8 472.3 MEAN 11.9 15.7 MAX 88 56 MIN 3.5 3.5 AC-FT 730 937 CFSM 9.42 12.5 IN. 10.86 13.94 STATISTICS OF MONTHLY MEAN MEAN 15.3 18.3 MAX 32.1 46.8 (WY) 1986 1951 MIN 4.78 8.00 (WY) 1993 1948 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 42 94 33 41 31 22 15 14 19 10 10 8.7 13 7.9 6.9 7.2 8.4 7.7 7.0 7.0 7.2 10 12 11 19 12 12 12 9.1 8.1 8.0 525.2 16.9 94 6.9 1040 13.4 15.51 DATA 15.3 31.3 1988 4.99 1990 FOR 9.5 13 10 8.4 8.0 7.7 7.2 6.9 10 8.4 8.9 21 14 11 15 10 8.2 8.0 7.2 7.2 7.2 6.4 6.7 6.0 5.8 48 65 48 11 8.8 8.5 421.0 13.6 65 5.8 835 10.8 12.43 8.0 7.4 8.0 7.7 7.4 8.0 9.6 9.0 9.0 8.2 15 10 9.2 10 18 17 13 12 14 9.8 14 6.3 5.1 4.7 94 29 107 75 ___ —— 545.4 19.5 107 4.7 1080 15.5 16.10 FOR WATER YEARS 1945 12.8 26.9 1952 6.65 1994 13.6 44.0 1950 4.86 1983 14 11 8.8 18 11 6.9 19 11 27 10 9.5 23 37 30 12 10 9.8 9.0 8.2 8.0 7.7 7.2 7.2 6.9 6.4 6.4 7.6 6.4 6.4 6.2 5.7 367.3 11.8 37 5.7 729 9.40 10.84 - 1995 10.5 26.1 1949 3.90 1951 1994 CALENDAR YEAR 3460.8 9.48 119 2.8 3.4 6860 7.53 102.18 19 5.4 3.6 Feb 19 Sep 5 Mar 4 5.7 5.7 5.7 5.7 5.7 5.4 5.1 5.1 5.1 5.1 5.1 12 5.3 5.1 6.0 19 7.8 7.1 6.4 6.4 6.3 5.7 6.1 6.4 6.4 6.4 6.2 5.7 5.4 5.1 —— 194.2 6.47 19 5.1 385 5.14 5.73 , BY WATER 12.3 34.4 1950 4.77 1984 FOR 1995 5073. 13. 139 3. 4. 779 5. 3. 10060 11. 149. 29 8. 5. 5.1 5.1 4.5 8.7 8.4 7.3 5.9 6.3 5.3 4.8 5.2 5.4 5.1 5.1 36 18 6.9 6.1 8.6 11 8.8 6.1 5.7 5.3 6.8 7.1 23 17 52 28 17 345.6 11.1 52 4.5 685 8.85 10.20 YEAR (WY) 16.8 26.3 1948 6.84 1994 10 23 37 10 6.9 17 15 6.9 5.7 7.7 37 23 14 12 22 12 9.2 6.8 6.2 8.6 8.1 7.4 6.4 6.3 5.7 5.8 5.8 5.5 5.1 5.1 --- 351.2 11.7 37 5.1 697 9.29 10.37 12.1 20.5 1987 5.19 1985 WATER YEAR 4 9 5 0 66 5 0 79 7 1 Sep 16 Oot 7 Oct 28 Feb 25 Feb 25 Oot 30 5.1 4.9 12 15 28 19 7.2 6.0 5.6 5.1 7.8 6.7 17 7.1 16 20 8.0 21 13 13 20 23 8.1 7.6 6.6 14 62 29 14 13 9.0 443.8 14.3 62 4.9 880 11.4 13.10 13.6 38.8 1952 7.21 1994 WATER 14. 21. 8. 470 1. 2. 2860 8. 2. 10330 11. 153. 29 8. 4. 25 16 31 10 8.8 12 15 32 13 11 9.5 8.4 8.0 7.2 7.2 7.6 16 32 18 9.9 13 9.4 13 13 9.9 8.2 7.4 7.9 17 19 9.7 425.1 13.7 32 7.2 843 10.9 12.55 14.1 24.5 1945 5.91 1993 YEARS 1945 - 3 0 00 Sep 18 5 Mar 22 0 Apr 7 Apr 21 96 Apr 21 9 Aug 29 3 69 1 5 6.9 6.2 5.8 5.0 31 87 12 32 12 10 19 10 8.6 7.4 18 139 39 18 14 16 16 12 11 10 9.6 9.3 9.1 11 20 9.6 614.5 20.5 139 5.0 1220 16.3 18.14 16.7 37.6 1989 7.03 1986 1995 1952 1994 1989 1946 1946 1983 1983 1992 SEA EXPLANATION AQ920 SURFACE-WATER STATION AND NUMBER V 0835 QUALITY-OF-WATER STATION AND NUMBER AQC WELL AND WELL NUMBER 'LAKE-ELEVATION STATION AND NUMBER 093050 Figure 22.--Southeastern river basins the Rio Humacao to Rfo Seco basins. IS) N 328 RIO HDMACAO BASIN 50081000 RIO HUMACAO AT LAS PXEDRAS, PR LOCATION.--Lat 18°10'27", long 65°52'11", Hydrologic unit 21010005, on left bank at downstream side of bridge on Highway 921, 0.6 mi (1.0 km) southeast of junction with Highway 30, 0.6 mi (1.3 km) downstream from Quebrada Blanca and 0.6 mi (1.3 km) south of Las Piedras. DRAINAGE AREA.--6.65 mi» (17.22 km2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.—September 1956 to December 1967 (monthly discharge measurements), July 1974 to September 1977, October 1967 to current year. GAGE.—Water-stage recorder and crest-stage gage. Elevation of gage is 260 ft (79 m), from topographic map. Prior to July 1974, crest-stage gage at different datum. July 1974 to September 1977 at site 90 ft (27 m) upstream at present datum. REMARKS.--Records fair except those above 1,000 fts/s (26.3 m'/s), which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT JAN APR MAY JUN 1 7.6 7.6 2 7.7 7.7 3 7.7 7.4 4 7.3 7.2 5 7.2 7.7 6 7.1 20 7 9.2 22 6 7.3 20 9 7.1 16 10 7.1 27 11 6.9 23 12 6.6 13 13 7.2 12 14 6.5 11 15 6.7 9.9 16 6.3 9.6 17 7.2 10 16 6.4 10 19 11 9.1 20 12 13 21 7.9 14 22 13 9.6 23 95 11 24 34 9.1 25 33 19 26 14 19 27 11 16 28 9.6 15 29 6.9 21 30 6.5 21 31 6.2 --- TOTAL 397.4 422.5 MEAN 12 . 6 14 . 1 MAX 95 27 MIN 6.3 7.2 AC-FT 768 638 CFSM 1.93 2.12 IN. 2.22 2.36 STATISTICS OF MONTHLY MEAN MEAN 29.5 38.3 MAX 74.9 126 (WY) 1975 1968 MIN 12 . 8 14 . 1 (WY) 1995 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 26 37 38 30 21 20 17 16 15 15 15 14 15 14 14 13 12 12 12 13 13 13 13 13 13 12 12 11 11 10 10 500 16.1 36 10 992 2.43 2.80 DATA 31.1 112 1968 11.5 1992 FOR 11 10 11 11 10 10 10 10 10 10 9.7 9.7 12 12 12 11 11 10 10 9.7 9.7 9.6 9.1 11 10 15 10 9.9 11 9.7 9.4 324.5 10.5 15 9.1 644 1.57 1.62 9.0 9.1 8.7 6.4 8.4 7.9 8.6 10 11 24 10 6.9 6.3 6.0 7.6 8.3 13 9.3 8.9 11 48 20 11 9.6 76 26 11 12 —— 412.2 14.7 76 7.8 618 2.21 2.31 FOR WATER YEARS 1974 18.5 34.1 1992 10.5 1995 15.4 22.1 1994 11.0 1977 9.6 13 9.3 16 54 15 13 14 20 12 10 9.6 9.7 9.4 8.6 6.3 8.0 7.9 6.0 8.0 7.9 7.7 7.6 7.9 8.2 6.0 7.7 7.8 7.5 7.6 7.6 349.5 11.3 54 7.5 693 1.70 1.96 - 1995 11.5 16.4 1989 9.10 1993 1994 CALENDAR YEAR 5175.7 14.2 337 5.4 5.9 10270 2.13 26.95 19 10 7.2 Sep 20 Jul 14 Jul 11 6.0 8.0 6.0 8.0 9.5 6.5 9.4 9.0 8.6 6.2 18 17 9.0 6.1 7.7 8.3 6.4 8.1 16 9.9 7.7 7.4 7.1 6.6 6.8 6.6 6.6 6.6 6.5 6.3 264.3 8.61 18 6.3 524 1.32 1.46 6.3 6.0 5.6 5.7 6.3 6.1 5.8 6.4 6.9 6.5 6.0 5.7 5.5 5.5 5.6 5.8 5.5 5.8 6.3 9.5 10 6.6 6.0 6.2 6.2 9.3 9.3 10 12 25 22 247.6 7.99 25 5.5 491 1.20 1.39 28 52 140 46 27 24 19 14 13 15 15 21 17 21 43 46 27 17 14 13 14 12 11 11 10 9.7 9.5 9.4 9.0 9.1 716.7 24.0 140 9.0 1430 3.60 4.02 9.0 6.6 8.2 6.0 18 13 13 11 10 6.5 8.9 12 6.5 8.3 17 21 13 12 11 9.3 12 10 11 10 9.1 8.7 213 27 26 22 16 595.1 19.2 213 8.0 1160 2.89 3.33 17 16 78 21 16 15 15 15 12 11 10 10 9.7 9.2 9.4 10 13 24 35 16 17 20 13 13 22 13 11 11 10 10 10 514.3 16.6 76 9.2 1020 2.49 2.86 10 10 9.7 9.7 21 183 27 20 16 14 36 29 18 15 27 162 86 39 27 56 34 25 23 22 20 21 19 19 19 18 1039.4 34.6 163 9.7 2060 5.21 5.81 , BY WATER YEAR (WY) 9.22 13.1 1976 5.86 1977 FOR 1995 5785. 15. 213 5. 5. 956 4. 5. 11480 2. 32. 25 10 7. 14.5 42.2 1992 7.26 1990 WATER YEAR 5 9 Jul 27 5 May 13 6 May 12 Jun 3 45 Jun 3 5 May 5 36 36 1 16.0 29.0 1992 5.91 1977 16.8 36.1 1993 7.95 1990 WATER 21. 37. 12. 1670 2. 2. 20800 34. 15290 3. 43. 31 13 6. 18.3 32.7 1977 9.45 1974 YEARS 1974 1 6 1 Nov 2 Jul 6 Jul Sep 40 Sep 17 13 9 30.8 54.1 1975 10.0 1990 - 1995 1968 1990 27 1987 15 1974 19 1974 6 1960 6 1960 RIO HUMACAO BASIN 329 50082000 RIO HUMACAO AT HIGHWAY 3 AT HUMACAO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°08'49", long 650 49'37", at bridge on Highway 3,300 ft (91 m) downstream from Quebrada Mariana, and 0.4 mi (0.6 km) south of Humaeao. DRAINAGE AREA.--17.3 mi 1 (44.8 km1 )• PERIOD OP RECORD.--Water year* 1958-66, 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 25. .. DEC 07. .. FEB 1995 13. .. APR 06. .. OXJN 07. .. AUG 08. .. DATE OCT 1994 25. .. DEC 07... FEB 1995 13. . . APR 06. .. OXJN 07. .. AUG 08. . . TIME 1015 0950 1015 1040 1005 0925 HARD- NESS TOTAL (MG/L AS CACO3) 59 -- -- 110 -- 86 SILICA, DATE OCT 1994 25. . . DEC 07. .. FEB 1995 13. .. APR 06. . . JUN 07. .. AUG 08. .. E = Estimated K = non-ideal DIS- SOLVED (MG/L AS SIO2) 25 -- -- 42 — 37 count DIS- CHARGE, INST. CUBIC FEET PER SECOND E100 34 12 9.9 30 25 CALCIUM DIS- SOLVED (MG/L AS CA) 16 -- -- 30 -- 23 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 109 -- -- 217 -- 185 SPE- CIFIC CON- DUCT- ANCE (US /CM) 117 275 319 301 250 310 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 4.7 — -- 7.7 • 6.9 SOLIDS, DIS- SOLVED (TONS PER DAY) E 29.4 -- — 5.81 -- 12.5 PH WATER WHOLE FIELD (STAND- ARD UNITS) 6.9 7.2 6.9 7.1 6.9 7.1 SODIUM, DIS- SOLVED (MG/L AS NA) 16 -- _- 28 -- 23 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 72 22 3 30 21 15 TEMPER- ATURE WATER (DEG C) 24.0 24.0 26.0 28.0 27.0 28.0 SODIUM AD- SORP- TION RATIO 0.9 — — 1 -- 1 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.50 0.20 4.1 0.70 0.41 0.38 TUR- BID- ITY (NTU) 74 20 2.5 13 17 6.4 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.9 __ _- 2.0 -- 2.4 PHOS- PHORUS TOTAL (MG/L AS P) 0.120 0.070 0.540 0.090 0.060 0.120 OXYGEN, DIS- SOLVED (MG/L) 6.8 4.8 3.8 4.8 6.8 8.6 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 30 92 100 100 89 100 ARSENIC TOTAL (UG/L AS AS) <1 -- — <1 — -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 80 56 46 60 84 109 SULFIDE TOTAL (MG/L AS S) <0.5 _- -- <0.5 -- ~ ~ BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) 100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 21 10 33 11 13 10 SULFATE DIS- SOLVED (MG/L AS SO4) 8.8 — — 9.5 -- 7.3 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 40 -- -- 30 -- -- COLI- FORM, FECAL, 0.45 OM-MF (COLS . / 100 ML) 24000 3700 440000 45000 K16000 5000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 18 __ -- 38 -- 25 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K1500 1300 29000 6100 1100 K1700 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 — -- 0.10 — 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 — -- 330 RIO HUMACAO BASIN 50082000 RIO HUMACAO AT HIGHWAY 3 AT HUMACAO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 25. .. DEC 07. . . FEB 1995 13. .. APR 06. .. JUN 07. . . AUG 08. .. COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 __ — 10 __ — IRON, TOTAL RECOV- ERABLE (UG/L AS FE) 2100 __ __ 940 __ __ LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) 1 __ __ 2 __ — MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 200 __ __ 290 __ __ MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 — __ <0.10 __ __ SELE- NIUM, TOTAL (UG/L AS SE) <1 __ __ <1 __ __ SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <1 __ — <1 __ __ ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) 10 __ __ 20 __ __ CYANIDE TOTAL PHENOLS (MG/L TOTAL AS CN) (UG/L) •eO.010 3 __ — <0.010 <1 __ — MBTHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) <0.02 _- __ 0.04 __ — ttIO GUAYANES BASIN 50083500 RIO GUAYANES AT YABUCOA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°03'33", long 65°54'03", at bridg* on Highway 182, 1.4 mi (2.2 km) w«et-northw«»t of plaza. DRAINAGE AREA.--17.2 mi 1 (44.6 km1 ). PERIOD OF RECORD.--Water years 1958-62, 1968-70, 1980 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 331 Yabucoa DATE OCT 1994 06. .. DEC 06... FEB 1995 06. .. APR 12. .. JUN 06... AUG 07... DATE OCT 1994 06. .. DEC 06... FEB 1995 06. .. APR 12... JTJN 06. .. AUG 07... TIME 1040 1020 1025 1030 1030 1035 HARD- NESS TOTAL (HG/L AS CAC03) 56 -- -- 83 -- 170 SILICA, DATE OCT 1994 06... DEC 06. .. FEB 1995 06. .. APR 12. .. JTJN 06. . . AUG 07. . . K • non- ideal DIS- SOLVED - (HG/L AS SIO2) 37 -- -- 36 ~- 25 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 26 79 26 41 56 28 CALCIUM DIS- SOLVED (MG/L AS CA) 14 -_ -- 20 __ 45 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 131 -- -_ 150 -- 194 SPE- CIFIC CON- DUCT- ANCE (US/CM) 176 173 200 266 142 180 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 5.0 __ -- 8.0 __ 14 SOLIDS, DIS- SOLVED (TONS PER DAY) 9.10 -- __ 16.5 _- 14.8 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.1 6.5 7.0 6.7 6.7 6.8 SODIUM, DIS- SOLVED (MG/L AS NA) 15 __ -- 21 _- 23 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 17 '49 35 37 71 20 TEMPER- ATURE WATER (DEG C) 26.0 24.0 23.0 25.0 26.0 27.5 SODIUM AD- SORP- TION RATIO 0.9 __ -- 1 __ 0.8 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.20 <0.20 0.30 0.50 0.37 0.43 TUR- BID- ITY (NTU) 5.0 26 23 9.2 37 8.0 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 1.6 __ __ 1.4 __ 3.0 PHOS- PHORUS TOTAL (MG/L AS P) 0.050 0.050 0.030 0.120 0.110 0.100 OXYGEN, DIS- SOLVED (MG/L) 7.4 1.4 4.0 4.8 7.2 4.4 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 66 56 67 57 54 67 ARSENIC TOTAL (UG/L AS AS) 1 -- -- <1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 89 16 46 57 87 55 SULFIDE TOTAL (MG/L AS S) <0.5 __ -- <0.5 __ -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 <10 <10 <10 12 15 SULFATE DIS- SOLVED (MG/L AS S04) 4.4 __ -- 8.4 __ 14 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 20 -- -- 20 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS. / 100 ML) 440 K1700 K8200 37000 K6400 K7500 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 14 __ -- 21 -- 30 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 __ -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K1500 K1900 720 26000 4900 K17000 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 __ -- 0.10 -- 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- 1 -- -- 332 RIO GUAYANES BASIN 50083500 RIO GUAYANES AT YABUCOA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 06. .. DEC 06. . . FEB 1995 06. .. APR 12. .. JUN 06. . . AUG 07. .. COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 IRON, TOTAL RECOV- ERABLE (UG/L AS FE) 1200 LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) <3. MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 140 MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 SELE- NIUM, TOTAL (UG/L AS SB) <x SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <x ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) <10 CYANIDE TOTAL (MG/L AS CN) <0.010 PHENOLS TOTAL (UG/L) <! METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) 0.02 60 14000 490 <0.10 60 <0.010 2 <0.02 PESTICIDE ANALYSES CHLOR- DANE, P,P'- P,P'- ENDO- TECH- ODD DOT DI- DI- SULFAN, PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I DATE TIME 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) JUN 1995 06... 1030 <0 ENDRIN WATER UNFLTRD DATE REC (UG/L) JUN 1995 06... <0.010 PARA- THION, DATE TOTAL (UG/L) .100 <0. ETHION, TOTAL (UG/L) <0.010 PCNS UNFILT RECOVER (UG/L) ,010 <0 HEPTA- CHLOR, TOTAL (UG/L) <0.010 PER- THANE TOTAL (UG/L) .100 <0, HEPTA- CHLOR EPOXIDE TOTAL (UG/L) <0.010 TOX- APHENE, TOTAL (UG/L) .010 <0, LINDANE TOTAL (UG/L) <0.010 TOTAL TRI- THION (UG/L) ,010 <0 MALA- THION, TOTAL (UG/L) <0.010 2,4-D, TOTAL (UG/L) .010 <0 METH- OXY- CHLOR, TOTAL (UG/L) <0.010 2,4,5-T TOTAL (UG/L) .010 <0 METHYL PARA- THION, TOTAL (UG/L) <0.01Q 2, 4-DP TOTAL (UG/L) .010 <0.010 MIREX, TOTAL (UG/L) <0.010 SILVEX, TOTAL (UG/L) JUN 1995 06.. . <0.010 <0.100 <0.100 <1.00 <0.010 <0.010 <0.010 <0.010 <0.010 RIO GUAYANES BASIN 50086500 RIO GUAYANES ABOVE MOUTH AT PLAYA DE GUAYANES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°03'45", long 65°49'42", at old railroad crossing, 0.2 mi (0.3 km) from mouth, 0.4 mi (0.6 km) west of Playa de Guayanes, and 3.5 mi (5.6 km) northeast of Yabucoa plaza. DRAINAGE AREA.--34.0 mi 1 (88.1 km'). PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 333 DATE OCT 1994 25. .. DEC 07. .. FEB 1995 13. .. APR 06. .. JUN 07. . . AUG 08. . . DATE OCT 1994 25... DEC 07... FEB 1995 13. .. APR 06. .. JUN 07. .. AUG 08. .. DATE OCT 1994 25. . . DEC 07. . . FEB 1995 13. .. APR 06. .. JUN 07. .. AUG 08. .. TIME 0825 0830 0835 0835 0820 0810 HARD- NESS TOTAL (MG/L AS CAC03) 32 -- -- 56 -- 46 SILICA, DIS- SOLVED (HG/L AS SIO2) 22 -- -- 37 -- 32 DIS- CHARGE, INST. CUBIC FEET PER SECOND E100 101 25 30 59 56 CALCIUM DIS- SOLVED (MG/L AS CA) 7.7 -- -- 14 -- 12 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 80 -- -- 146 __ 123 SPE- CIFIC CON- DUCT- ANCE (US /CM) 117 184 285 173 162 165 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 3.0 -- -- 5.0 -- 4.0 SOLIDS, DIS- SOLVED (TONS PER DAY) E21.6 -- __ 11.8 __ 18.7 PH WATER WHOLE FIELD (STAND- ARD UNITS) 6.9 6.8 7.2 7.0 6.9 7.0 SODIUM, DIS- SOLVED (MG/L AS NA) 10 -_ -_ 17 __ 15 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 166 50 15 19 41 65 TEMPER- ATURE WATER (DEG C) 24.0 24.0 25.0 27.5 26.0 27.0 SODIUM AD- SORP- TION RATIO 0.8 __ __ 1 -- 1 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.80 0.20 <0.20 0.30 0.32 0.61 TUR- BID- ITY (NTU) 120 28 8.1 13 39 55 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.8 __ -- 2.1 -- 2.0 PHOS- PHORUS TOTAL (MG/L AS P) 0.170 0.080 0.030 0.040 0.040 0.140 OXYGEN, DIS- SOLVED (MG/L) 6.8 5.8 4.7 6.0 6.8 6.8 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 30 62 66 75 61 65 ARSENIC TOTAL (UG/L AS AS) <1 -- -- <1 __ — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 81 68 56 74 82 85 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 -- - - BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) 100 -- -- <100 _- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 25 10 <10 13 <10 15 SULFATE DIS- SOLVED (MG/L AS SO4) 5.2 -- -- 6.4 -- 5.0 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 100 -- -- 20 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS. / 100 ML) 24000 K1400 3300 K1200 2900 47000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 11 -- __ 19 _- 14 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K1400 2100 7600 860 2100 K1700 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 -- -- 0.10 -- 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 -- -- E = Estimated K = non-ideal count 334 RIO GUAYANES BASIN 50086500 RIO GUAYANES ABOVE MOUTH AT PLAYA DE GUAYANES, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 25. . . DEC 07. .. FEB 1995 13. .. APR 06. .. JUN 07. .. AUG 08. .. COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS FE) AS PB) AS MN) AS HG) AS SB) AS AG) AS ZN) AS CN) (UG/L) 10 4500 1000 220 120 <0.10 <0.10 20 <0.010 10 <0.010 (MG/L) <0.02 0.03 RIO HAUNABO BASIN 50090500 RIO MAUNABO AT LIZAS, PR LOCATION.--Lat 18«>01'38", long 65°56'24", Hydrologic Unit 21010005, on right bank, off Highway 759 at Lizas, about 1.0 mi (1.6 km) downstream from Quebrada Coroco, and about 3.0 mi (4.8 km) northwest of Maunabo. 335 DRAINAGE AREA.--5.38 mi 1 (13.93 km1 )- HATER-DISCHARGE RECORDS PERIOD OP RECORD.—February 1971 to January 1985, February 1991 to current year. GAGE.--Hater-stage recorder and crest-stage gage. Elevation of gage is 230 ft (70 m), from topographic map. REMARKS.—Records poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY DEC FEB MAR JUL AUG SEP 1 ell e!5 2 ell e20 3 elO e45 4 e9.4 e37 5 e9.4 e74 6 ell e64 7 elO e84 8 elO e68 9 e9.6 e88 10 e9.6 e80 11 e9.0 e50 12 e9.0 e41 13 e9.0 e38 14 e8.4 e32 15 e8.4 e30 16 e9.0 e29 17 e20 e28 18 ell e27 19 e9.6 e28 20 e9.6 e42 21 e62 e35 22 6160 e45 23 6120 e38 24 e68 e45 25 e42 e64 26 e30 e!20 27 e25 e50 28 e21 e38 29 el 9 e50 30 e!8 e76 31 e!8 TOTAL 787.0 1481 MEAN 25.4 49.4 MAX 160 120 MIN 8.4 15 AC-FT 1560 2940 CFSM 4.72 9.18 IN. 5.44 10.24 STATISTICS OF MONTHLY MEAN MEAN 27.0 32.3 MAX 52.6 88.9 (WY) 1979 1978 MIN 10.4 7.46 (WY) 1994 1982 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS e!60 e72 e64 e45 e32 e31 e27 e23 e23 e27 e29 e22 e20 e70 630 620 e!7 616 e!6 e!6 el 6 620 e!8 e!8 616 616 e!5 e!4 e!4 e!3 e!3 933 30.1 160 13 1850 5.59 6.45 DATA 18.3 35.2 1978 8.74 1994 FOR e 14 e 15 e 14 e!3 e!3 12 12 11 12 12 11 11 11 11 13 11 11 11 10 9.2 8.6 8.3 8.2 8.4 8.5 11 8.5 8.8 8.1 7.8 7.7 331.1 10.7 15 7.7 657 1.99 2.29 7.6 7.5 7.3 7.2 6.9 7.2 12 10 8.5 14 9.9 8.6 7.7 7.5 9.6 13 12 11 13 15 81 23 13 11 57 26 34 188 ___ 628.5 22.4 188 6.9 1250 4.17 4.35 FOR HATER YEARS 1971 12.5 27.1 1992 7.79 1981 11.9 24.5 1982 6.10 1979 29 22 16 18 32 16 14 14 12 11 11 10 10 9.7 9.9 9.4 9.3 9.1 8.9 8.4 8.3 8.1 7.8 7.7 7.4 7.1 7.1 6.9 6.8 6.6 6.4 359.9 11.6 32 6.4 714 2.16 2.49 - 1995 9.60 18.9 1976 4.32 1979 1994 CALENDAR YEAR 6125.6 16.8 270 4.2 4.5 12150 3.12 42.36 38 8.4 5.2 Sep 20 Jul 6 Jul 11 6.2 6.3 6.2 5.9 6.9 6.3 7.6 6.0 5.4 5.2 5.0 7.4 5.2 4.8 4.6 4.8 5.5 5.3 5.4 4.7 4.4 4.5 4.6 4.6 4.7 4.5 4.4 4.5 e4.3 e4.3 159.5 5.32 7.6 4.3 316 .99 1.10 e4.3 e4.1 64.1 e5. 0 e6.6 ell e!7 630 6.3 4.5 4.2 4.1 3.9 4.0 5.8 5.4 4.3 4.3 4.4 7.0 5.4 4.3 4.0 6.0 7.1 13 6.6 5.4 9.9 7.5 14 223.5 7.21 30 3.9 443 1.34 1.55 31 55 41 24 12 9.2 15 9.7 7.8 7.2 11 9.4 7.8 13 36 17 13 10 9.3 8.8 11 9.7 7.8 7.4 7.0 6.7 6.5 6.3 6.2 6.8 422.6 14.1 55 6.2 838 2.62 2.92 6.3 6.0 6.0 e7.3 e9.5 e7.8 e8.5 ell e8.2 e6.1 e6.7 e9.0 e6.4 e6.1 e8.5 e!2 e7.5 e6.0 e5.3 e4.8 e4.9 e7.7 e5.3 e4.7 e6.5 ell e!6 e9.4 e6.0 e7.2 eS.O 235.7 7.60 16 4.7 468 1.41 1.63 e6.2 4.9 10 7.6 6.6 6.9 8.8 16 9.6 8.9 7.7 6.6 6.4 6.0 5.6 5.9 7.4 26 137 44 18 25 18 14 13 9.6 8.1 7.4 7.2 6.7 6.5 471.6 15.2 137 4.9 935 2.83 3.26 6.4 6.8 7.2 6.9 17 77 34 27 16 13 28 21 20 21 37 138 68 35 29 43 40 31 38 30 27 131 58 30 50 29--- 1115.3 37.2 138 6.4 2210 6.91 7.71 , BY WATER YEAR (WY) 6.98 10.8 1976 3.92 1979 FOR 1995 7148. 19. 188 3. 4. 2060 9. 14180 3. 49. 43 10 5. 13.2 25.1 1979 5.13 1974 WATER YEAR .7 .6 Feb 28 . 9 May 13 .3 Apr 27 Sep 26 .70 Sep 26 .64 .43 ,3 17.1 47.1 1979 4.40 1974 17.3 40.2 1993 3.70 1974 WATER 18. 36. 10. 2480 2. 2. 9950 17. 13020 3. 45. 32 11 5. 22.9 131 1979 6.18 1974 YEARS 1971 0 7 8 Aug 2 Jul 8 Jul Sep 46 Sep 34 38 2 25.7 81.5 1979 7.99 1980 - 1995 1979 1994 31 1979 16 1974 11 1974 20 1994 20 1994 e Estimated 336 RIO MAUNABO BASIN 50091000 RIO MAUNABO AT MAUNABO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°00'24", long 65 0 54'19", at bridge on Highway 3, 0.4 mi (0.6 km) southwest of Maunabo plaza, and 1.3 mi (2.1 km) upstream from mouth. DRAINAGE AREA.--12.4 mi 1 (32.1 km 1 ). PERIOD OF RECORD.--Water years 1958-66, 1975 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 06. .. DEC 06. .. FEE 1995 06. . . APR 12. .. JUN 06. .. AUG 07. .. DATE OCT 1994 06. .. DEC 06. . . FEE 1995 06. .. APR 12. .. JUN 06. .. AUG 07. .. TIME 0840 0845 0815 0745 0845 0840 HARD- NESS TOTAL (MG/L AS CAC03) 86 -- -- 56 — 170 SILICA, DATE OCT 1994 06. .. DEC 06. .. FEE 1995 06... APR 12... JUN 06. . . AUG 07. . . K = non-ideal DIS- SOLVED (HG/L AS SI02) 34 -- __ 36 -- 18 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 3.2 5.3 12 15 18 10 CALCIUM DIS- SOLVED (MG/L AS CA) 22 -- -- 14 -- 53 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 208 -- -- 147 -- 236 SPE- CIFIC CON- DUCT- ANCE (US /CM) 456 215 312 196 238 260 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 7.6 -- — 5.1 -- 10 SOLIDS, DIS- SOLVED (TONS PER DAY) 1.77 — — 5.79 __ 6.51 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.2 6.8 7.2 7.0 6.7 6.8 SODIUM, DIS- SOLVED (MG/L AS NA) 21 __ -- 17 __ 32 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 11 37 16 372 6 14 TEMPER- ATURE WATER (DEG C) 26.5 25.0 23.0 25.0 26.5 27.0 SODIUM AD- SORP- TION RATIO 1 — __ 1 — 1 NITRO- GEN .AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.30 <0.20 o.eo 0.30 0.23 0.25 TUR- BID- ITY (NTU) 2.9 29 8.3 200 5.0 4.5 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.4 -- -- 1.6 -- 1.4 PHOS- PHORUS TOTAL (MG/L AS P) 0.100 0.050 0.080 0.050 0.030 0.060 OXYGEN, DIS- SOLVED (MG/L) 2.6 5.8 4.6 3.3 8.0 4.4 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CAC03 150 60 95 90 64 93 ARSENIC TOTAL • (UG/L AS AS) 2 -- __ <1 — -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 32 69 53 39 98 55 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 -- — — BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 12 <10 35 <10 10 SULFATE DIS- SOLVED (MG/L AS S04) 10 — __ 4.1 — 40 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 30 __ __ 20 — — COLI- FORM, FECAL, 0.45 UM-MF (COLS. / 100 ML) 480000 f K850 3700 2500 3900 2200 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 21 -- -- 15 -- 26 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 57000 2600 280 560 870 34000 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 — -- 0.10 -- 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- — <1 -- — RIO MAUNABO BASIN 337 50091000 RIO MAUNABO AT MAUNABO, PR- -Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 06. . . DEC 06. . . FEB 1995 06. . . APR 12. .. JUN 06. . . AUG 07. .. COPPER, IRON, TOTAL TOTAL RECOV- RECOV- ERABLE ERABLE (UG/L (UG/L AS CO) AS FE) <10 490 __ __ 20 1600 __ __ MANGA- LEAD, NESE, TOTAL TOTAL RECOV- RECOV- ERABLE ERABLE (UG/L (UG/L AS PB) AS MN) 1 70 __ __ 2 110 __ __ MERCURY TOTAL SELE- RECOV- NIUM, ERABLE TOTAL (UG/L (UG/L AS HG) AS SE) <0.10 <1 __ __ <0.10 <1 __ __ SILVER, ZINC, TOTAL TOTAL RECOV- RECOV- CYANIDE ERABLE ERABLE TOTAL PHENOLS (UG/L (UG/L (MG/L TOTAL AS AG) AS ZN) AS CN) (UG/L) <1 <10 <0.010 <1 __ __ <1 10 <0.010 2 __ __ METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) 0.03 -- -- <0.02 -- -- 338 RIO CHICO BASIN 50091800 RIO CHICO AT PROVIDENCIA, PR WATER-QUALITY RECORDS LOCATION.--Lat 17°59'16", long 66°00'18", at flat low bridge 200 ft (61 m) south of Highway 3, 0.5 mi (0.8 km) above mouth, and 1.5 mi (2.4 km) southeast of Patillae plaza. DRAINAGE AREA.--4.9 mi 1 (12.8 km1 ). PERIOD OF RECORD.—Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 28. .. DEC 13. .. FEB 1995 14. .. APR 18. .. JUN 15. .. AUG 09. .. DATE OCT 1994 28. .. DEC 13. .. FEB 1995 14. .. APR 18. .. JUN 15. .. AUG 09. .. TIME 0850 0835 0840 0815 0755 0805 HARD- NESS TOTAL (MG/L AS CACO3) 92 -- -- £6 — 84 SILICA, DATE OCT 1994 28... DEC 13. .. FKB 1995 14... APR 18. .. JTJN 15. .. AUG 09. . . K « non- ideal DIS- SOLVED (MG/L AS SIO2) 30 — __ 27 -- 27 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 6.4 7.8 2.4 0.58 13 1.9 CALCIUM DIS- SOLVED (MG/L AS CA) 22 -- -- 17 -- 20 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 195 -- -- 225 -- 211 SPE- CIFIC CON- DUCT- ANCE (US /CM) 322 295 392 428 250 400 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 9.0 __ — 5.6 — 8.2 SOLIDS, DIS- SOLVED (TOMS PER DAT) 3.35 — -- 0.35 -- 1.08 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.7 7.4 7.4 6.8 7.3 7.1 SODIUM, DIS- SOLVED (MG/L AS HA) 31 __ -_ 52 __ 39 RESIDUE TOTAL AT 105 DSG. C, SUS- PENDED (MO/L) 8 15 21 11 156 9 TEMPER- ATURE WATER (DEG C) 25.5 25.0 26.0 28.0 25.0 28.0 SODIUM AD- SORP- TION RATIO 1 — -- 3 — 2 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.40 0.60 1.6 2.5 1.9 1.2 TUR- BID- ITY (NTU) 1.9 15 1.5 4.2 88 1.9 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.1 __ -- 9.6 — 5.6 PHOS- PHORUS TOTAL (MG/L AS P) 0.440 0.460 1.90 3.20 0.540 1.70 OXYGEN, DIS- SOLVED (MG/L) 4.6 5.0 5.2 1.6 5.8 3.5 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 98 94 82 54 84 89 ARSENIC TOTAL (UG/L AS AS) <1 -- -- 1 — -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 55 59 63 20 69 44 SULFIDE TOTAL (MG/L AS S) <0.5 __ -- <0.5 -_ — — BARIUM, TOTAL RECOV- ERABLE (UO/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 13 28 48 42 51 SULFATE DIS- SOLVED (MG/L AS SO4) 16 -- — 28 — 19 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 40 -- — 130 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS . / 100 ML) K720 38000 K7200 K1600 3700 2100 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 26 -- -- 53 _- 39 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 610 3600 3900 K1300 600 K900 FLUO- RIDB, DIS- SOLVED (MG/L AS F) 0.10 — -- 0.10 — 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 — — RIO CHICO BASIN 50091800 RIO CHICO AT PROVIDENCIA, PR—Continued WATSR-QDALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 339 COPPER, TOTAL RECOV- ERABLE (OG/L IRON, TOTAL RECOV- ERABLE (OG/L LEAD, TOTAL RECOV- ERABLE (OG/L MANGA- NESE, TOTAL RECOV- ERABLE (OG/L MERCURY TOTAL RECOV- ERABLE (OG/L SELE- NIUM, TOTAL (OG/L SILVER, TOTAL RECOV- ERABLE (OG/L ZINC, TOTAL RECOV- ERABLE (OG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CO) AS PE) AS PB) AS MN) AS HO) AS SE) AS AG) AS ZN) AS CN) (OG/L) (MG/L) OCT 1994 28. .. DEC 13. .. FEB 1995 14... APR 18... JUN 15. .. AOG 09. .. 20 20 190 190 20 30 <0.10 <0.10 10 <0.010 2 0.04 20 <0.010 340 RIO GRANDE DE PATILLAS BASIN 50092000 RIO GRANDE DE PATILLAS NEAR PATILLAS, PR LOCATION.--Lat 18°02'04", long 66°01'58", Hydrologic Unit 21010004, on left bank, at foot bridge, off Highway 184, 1.2 mi (1.9 km) upstream from Lago Patilias Dam and 2.2 mi (3.5 km) northwest of Patillas. DRAINAGE AREA.--18.3 mi 2 (47.4 km*). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1959 to October 1965 (annual low-flow and occasional measurements only), January 1966 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 235 ft (72 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT NOV DEC FEB MAR JUN JUL AUG SEP 1 24 27 2 23 24 3 23 27 4 22 37 5 21 31 6 21 61 7 23 53 8 21 70 9 21 56 10 20 71 11 20 66 12 19 43 13 19 34 14 19 31 15 18 27 16 18 25 17 19 24 18 41 23 19 22 22 20 20 23 21 20 e27 22 68 e23 23 248 e29 24 180 e24 25 103 e28 26 65 e40 27 45 e82 28 37 e35 29 32 25 30 29 31 31 27 —— TOTAL 1288 1119 MEAN 41.5 37.3 MAX 248 82 MIN 18 22 AC-FT 2550 2220 CFSM 2.27 2.04 IN. 2.62 2.27 STATISTICS OF MONTHLY MEAN MEAN 98.9 92.0 MAX 593 393 (WY) 1971 1978 MIN 14.4 16.1 (WY) 1968 1968 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 46 107 48 42 32 25 21 18 15 e!5 e!7 e!8 el4 e!3 e60 e30 e24 e22 e21 e20 e20 e20 e26 ©23 e23 e21 e21 e20 e!9 e!8 e!7 836 27.0 107 13 1660 1.47 1.70 DATA 51.3 152 1971 8.63 1968 FOR e!7 e!8 e!9 e!8 e!7 e!7 e!6 e!5 e!5 e!8 e!5 e!9 e24 e!8 e!7 e!6 e!5 e!5 e!4 el3 e!3 e!2 ell ell e!2 e66 e40 e29 e24 e21 el8 593 19.1 66 11 1180 1.05 1.21 e!6 e!5 e!6 e!6 e!5 e!3 e!3 e23 e!8 e22 e!7 e!8 e!5 e!2 ell e!5 e22 e20 e25 e27 elOO e62 e40 e32 elOO ellO e70 e56 ___ --- . --- 919 32.8 110 11 1820 1.79 1.87 FOR WATER YEARS 1966 33.8 125 1992 14.0 1973 28.1 94.6 1982 7.09 1973 e45 e37 e30 e33 e68 e50 e31 e36 e37 e30 e23 e22 e24 e33 e29 e25 e22 e21 e20 e!9 e!8 el8 e!7 el6 el5 e!4 e!4 e!3 el3 el2 e!2 797 25.7 68 12 1580 1.40 1.62 - 1995 23.9 43.8 1972 6.74 1968 1994 CALENDAR YEAR 8474.1 23.2 353 8.5 9.1 16810 1.27 17.23 37 16 10 Sep 20 May 2 Apr 27 ell ell ell ell ell el4 e!5 e!8 e!3 e!2 ell e29 e21 e!3 ell e!9 e!5 ell elO e9.6 e9.2 e8.6 e7.8 e7.8 e7.8 e7.0 e7.0 e7.0 e6.4 e6.4 —— 351.6 11.7 29 6.4 697 .64 .71 e6.4 e6.4 e6.0 e6.0 e6.6 e9.0 e!2 e22 e44 e!5 elO e8.4 e7.4 e!4 e!3 e31 e!5 e9.2 e7.6 e!6 el8 e!3 ell elO e9.4 e9.4 e8.6 e9.8 e!2 el6 e31 413.2 13.3 44 6.0 820 .73 .84 e20 e!78 148 92 50 38 42 31 25 25 86 31 25 25 57 48 34 27 25 23 27 24 21 20 19 18 20 20 18 18 --- 1235 41.2 178 18 2450 2.25 2.51 17 16 16 22 24 20 21 20 18 17 17 22 53 35 42 56 32 32 26 24 56 56 32 32 30 26 73 46 45 71 66 1063 34.3 73 16 2110 1.87 2.16 40 35 54 36 29 26 25 31 29 25 22 24 24 23 23 22 25 46 277 91 52 46 38 34 41 28 23 21 22 18 17 1247 40.2 277 17 2470 2.20 2.53 16 16 16 15 21 203 157 162 63 45 51 53 43 39 119 478 307 162 103 88 120 82 148 116 84 99 105 76 163 92 3242 108 478 15 6430 5.91 6.59 , BY WATER YEAR (WY) 21.7 43.4 1976 9.98 1968 FOR 1995 13103. 35. 478 6. 6. 1400 7. 25990 1. 26. 70 22 11 52.2 172 1969 10.3 1974 WATER YEAR 8 9 Sep 16 0 May 3 3 Apr 29 Aug 19 75 Aug 19 96 64 65.1 200 1979 13.1 1974 65.2 164 1979 14.1 1974 WATER 56 117 19 4780 4 5 30900 4 41090 3 42 97 27 12 70.3 231 1979 17.2 1994 YEARS 1966 - .7 .8 Sep 16 . 8 May 9 . 0 Apr 10 Jan 5 .6 May 13 .10 .11 84.6 314 1979 12.1 1967 1995 1979 1994 1975 1968 1968 1992 1968 e Estimated RIO GRANDE DE PATILLAS BASIN 50092000 RIO GRANDE DE PATILLAS NEAR PATILLAS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1960 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 341 DATE OCT 1994 28... DEC 13. .. FEB 1995 14. .. APR 18. . . JUN 15. .. AUG 09. .. DATE OCT 1994 28... DEC 13. .. FEB 1995 14. .. APR 18. .. JUN 15. .. AUG 09... TIME 1050 1025 1020 1040 1000 1020 HARD- NESS TOTAL (MG/L AS CAC03) 50 -- -- 54 -- 42 SILICA, DATE OCT 1994 28... DEC 13. .. FEB 1995 14. .. APR 18. .. JUN 15. .. AUG 09. . . K = non-ideal DIS- SOLVED (MG/L AS SI02) 25 -- — 22 -- 21 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 40 14 12 9.7 48 29 CALCIUM DIS- SOLVED (MG/L AS CA) 12 __ -- 13 _- 9.6 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 107 -- -- 114 -- 95 SPE- CIFIC CON- DUCT- ANCE (US/CM) 167 160 160 167 130 140 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 4.9 -- -- 5.2 -- 4.3 SOLIDS, DIS- SOLVED (TONS PER DAY) 11.5 -_ -- 3.0 -- 7.4 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.3 7.6 7.4 7.7 7.1 7.6 SODIUM, DIS- SOLVED (MG/L AS NA) 14 __ __ 15 _- 12 RESIDUE TOTAL AT 105 DBG. C, SUS- PENDED (MG/L) 2 4 4 2 35 6 TEMPER- ATURE WATER (DEG C) 26.0 25.0 25.0 26.0 25.0 28.0 SODIUM AD- SORP- TION RATIO 0.9 __ -- 0.9 __ 0.8 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 <0.20 <0.20 <0.20 0.27 0.22 TUR- BID- ITY (NTU) 1.0 2.8 0.30 0.40 23 0.60 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 0.60 __ -- 1.1 __ 0.60 PHOS- PHORUS TOTAL (MG/L AS P) <0.010 0.010 <0.010 0.010 0.030 0.020 OXYGEN, DIS- SOLVED (MG/L) 7.4 5.4 7.5 4.2 7.5 5.8 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CAC03 46 51 49 59 52 48 ARSENIC TOTAL (UG/L AS AS) <1 -- -- <1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 89 64 89 51 89 74 SULFIDE TOTAL (MG/L AS S) <0.5 __ -- <0.5 -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 10 <10 <10 <10 11 <10 SULFATE DIS- SOLVED (MG/L AS S04) 11 -- -- 10 -_ 8.1 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 30 -- -- 20 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS . / 100 ML) 210 3600 K140 220 4300 310 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 12 -- -- 12 -- 11 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS . PER 100 ML) 220 490 K170 610 K12300 290 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 -_ -- 0.20 -- <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 -- -- 342 DATE OCT 1994 28. .. DEC 13. .. FEB 1995 14. .. APR 18. .. JUN 15. .. AUG 09. . . RIO GRANDE DE PATILLAS BASIN 50092000 RIO GRANDE DE PATILIAS NEAR PATILIAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) 50 40 10 <0.10 <0.10 <0.010 <0.010 (M6/L) 0.02 RIO PATILLAS BASIN 50093045 LAOO PATILLAS AT DAMSITE NEAR PATILLAS, PR LOCATION.--Lat 18°01'15", long 66°01'19", Hydrologic Unit 21010004, on right bank, in a concrete tower at Damaite, 1.05 mi (1.69 km) northeaat from Patillaa plaza, 0.45 mi (0.72 km) northeast from Eacuela Segunda Unidad de Real and 2.30 mi (3.70 km) from Eacuela Segunda Unidad de Jeaua Maria Rodrfguez. DRAINAGE AREA.--25.2 mi 1 (65.3 km1 ). ELEVATION RECORDS PERIOD OF RECORD.--March 1995 to September 1995. GAGE.—Water atage recorder. Datum of gage ia mean aea level. 343 REMARKS.--Lago Patillaa waa completed in 1914. The dam ia a aemihydraulic earthfill atructure about 147 ft (45 m) height, a top width of 15 ft (4.6 m), maximum pool elevation oC 230 ft (70.1 m), a baae width of 625 ft (190 m) , a creat lenght of 1,067 ft (325 m) and haa maximum pool atorage of 17,073 ac-ft (21.05 hm3 ) . The Patillaa Dam ia owned by the Puerto Rico Electric Power Authority (P.R.B.P.A) and ita primary purpoae ia for irrigation of landa aerved by the Patillaa irrigation canal. Gage-height and precipitation satellite telemetry at atation. EXTREMES OBSERVED FOR CURRENT PERIOD.—Maximum elevation 222.37 ft (67.78 m), Sept. 16; minimum elevation, 211.19 ft (64.37 m). May 29. Capacity Table (baaed on data from Puerto Rico Electric Power Authority) Elevation, in feet 143 190 Contenta, in acre-feet 0 5,492 Elevation, in feet 200 225 Contenta, in acre-feet 7,752 15,005 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES DAY 1 2 3 4 5 6 7 B 9 10 11 12 13 14 15 16 17 IB 19 20 21 22 23 24 25 26 27 2B 29 30 31 MAX MIN DEC JAN FEB APR MAY SEP 220. 220. 220. 220. 220. 219. 219. 219. 219. 219. 219. 219. _ - 97 67 30 17 01 92 BO 92 B5 74 64 58 __ — 219.45 219.34 219.22 219.09 219.00 218.90 218.79 218.68 218.55 21B.43 21B.34 218.30 218.19 21B.OB 218.01 217.93 217.83 217.67 217.47 217.31 217.17 217.03 216. BB 216.74 216.59 216.45 216.29 216.20 216.09 215. 96 —— 219.45 215. 98 215. 215. 215. 215. 215. 214. 214. 214. 214. 214. 214. 213. 213. 213. 213. 213. 213. 212. 212. 212. 212. 212. 211. 211. 211. 211. 211. 211. 211. 211. 211. 215. 211. 81 65 43 23 03 83 69 52 38 20 03 85 67 50 32 20 01 82 62 49 31 16 98 81 65 54 39 25 29 34 59 81 25 211 213 214 215 215 215 215 215 215 215 216 216 216 216 216 217 217 217 217 217 217 217 217 217 217 217 216 216 216 216 217 211 .82 .90 .74 .18 .28 .37 .57 .66 .70 .73 .33 .42 .43 .48 .94 .22 .31 .34 .38 .37 .41 .43 .35 .28 .19 .06 .95 .84 .73 .60 --- .43 .82 216. 216. 216. 216. 216. 215. 215. 215. 215. 215. 215. 215. 215. 215. 215. 216. 216. 216. 216. 216. 216. 216. 216. 216. 216. 216. 217. 217. 217. 218. 218. 218. 215. 47 33 19 10 08 97 88 79 68 56 46 41 60 65 86 17 19 23 18 15 48 85 95 97 96 93 40 60 81 32 70 70 41 218 218 219 219 219 219 219 219 219 219 219 219 219 219 219 219 219 219 221 221 220 220 220 220 220 220 219 219 219 218 218 221 218 .85 .99 .32 .42 .47 .48 .52 .67 .73 .71 .65 .60 .53 .46 .38 .30 .31 .62 .14 .06 .78 .64 .50 .33 .25 .03 .80 .49 .23 .99 .88 .14 .85 218.88 218.78 218.74 218.66 216.88 219.81 221.61 221.37 220.89 220.82 221.06 221.08 221.28 221.37 219.37 221.08 221.70 220.93 220.91 221.19 222.01 221.84 222.02 221.09 A A A No gage-height record 344 THIS PAGE WAS LEFT BLANK INTENTIONALLY EXPLANATION A 1080 SURFACE-WATER STATION AND NUMBER V 1065 QUALITY-OF-WATER STATION AND NUMBER 1109 DAILY SEDIMENT STATION AND NUMBER 87 WELL AND WELL NUMBER 11 n LAKE-ELEVATION STATION AND NUMBER ™» «^«. / -•v?^^'~-"^'^W-V,s!t»^""J'' - Map orea SEA Figure 23.--South coast river basins the Rio Salinas to Rio Jacaguas basins. 346 50100200 RIO SALINAS BASIN RIO LAPA NEAR RABO DEL BUEY, PR LOCATION.—Lat a8°03'36", long 66°14'28", Hydrologic Unit 21010004, on left bank, at bridge on Highway 1, Km 9.7, 1.5 mi (2.4 km) north of Rabo del Buey, and 4.4 mi (7.1 km) northeast of Salinas Plaza. DRAINAGE AREA,—9.92 mi 2 (25.69 km2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.—1953-63 (annual low-flow measurements only), September 1988 to current year. GAGE.—Water-stage recorder and crest-stage gage. Elevation of gage is 394 ft (120 m), from topographic map. REMARKS.—Records poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES SEP 1 .02 1.1 2 .01 1.1 3 .00 1.1 4 .00 1.1 5 .00 1.1 6 .00 1.1 7 .01 1.0 8 .00 .99 9 .00 .99 10 .00 1.0 11 .00 1.0 12 .00 1.1 13 .00 1.3 14 .00 1.3 15 .00 1.2 16 .00 1.2 17 .13 1.2 18 .47 1.2 19 .31 1.1 20 .15 1.1 21 .09 1.2 22 23 1.2 23 92 1.1 24 3.8 .99 25 2.1 .99 26 1.5 .96 27 2.0 .92 28 1.3 .92 29 1.2 .94 30 1.1 .95 31 1.1 —— TOTAL 130.29 32.45 MEAN 4.20 1.08 MAX 92 1.3 MIN .00 .92 AC-FT 258 64 CFSM .42 .11 IN. .48 .12 STATISTICS OF MONTHLY MEAN MEAN 14.6 6.03 MAX 76.1 28.4 (WY) 1991 1991 MIN 1.46 1.07 (WY) 1992 1994 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS e.92 .75 .80 .76 .79 .86 .84 .75 .75 .75 .74 .73 .75 .75 .74 .70 .70 .70 .76 .76 .72 .71 .77 .77 .76 .75 .74 .67 .66 .68 .64 23.17 .75 .92 .64 46 .07 .09 DATA 1.92 6.09 1991 .75 1995 .65 .65 .68 .65 .65 .68 .65 .60 .60 .56 .55 .52 .52 .52 .51 .46 .43 .42 .40 .38 .36 .36 .34 .35 .37 .39 .34 .33 .33 .33 .33 14.91 .48 .68 .33 30 .05 .06 FOR WATER 10.9 68.8 1992 .47 1994 .33 .33 .33 .31 .31 .31 .33 .33 .32 .33 .31 .29 .29 .29 .29 .27 .27 .27 .27 .27 .35 .49 .46 .44 24 53 4.4 1.1 —— 90.29 3.22 53 .27 179 .32 .34 YEARS 1988 3.22 12.4 1991 .49 1990 1.1 1.0 .99 .99 .91 .86 .86 .86 .87 .86 .86 .86 .86 .94 .99 .97 .92 .92 .92 .92 .92 .93 .92 .92 .89 .88 .92 .92 .98 .99 1.0 28.73 .93 1.1 .86 57 .09 .11 - 1995 1.03 2.08 1992 .44 1990 FOR 1994 CALENDAR YEAR 270. . 92 m . 536 . 1. . . . 32 74 Oct 23 00 Jun 24 00 Jul 21 074 01 99 29 00 1.1 1.0 .99 .98 .99 .99 1.1 1.1 1.1 1.1 1.1 1.3 1.1 1.1 1.8 1.3 1.2 1.2 1.2 1.3 1.3 1. 1. 1. 1. 1. 1. 1. 1. 1.—— 37.05 1.23 1.8 .98 73 .12 .14 el. 3 el. 3 el. 3 el. 3 el. 2 2.5 2.5 2.5 1.7 1.5 1.5 1.4 1.4 1.4 1.4 1.5 1.4 1.2 .99 1.4 1.2 1.1 1.1 1.0 1.1 1.1 1.2 1.3 1.3 1.4 1.6 44.09 1.42 2.5 .99 87 .14 .16 1.9 1.8 1.7 1.9 1.7 1.5 1.5 1.6 1.7 1.8 2.0 2.0 1.8 1.7 1.7 1.6 1.6 1.6 1.6 1.5 1.9 1.7 1.7 1.6 1.6 1.6 1.8 1.8 1.6 1.5 —— 51.0 1.70 2.0 1.5 101 .17 .19 1.4 1.3 1.2 1.3 1.4 1.4 1.4 1.2 1.1 .98 .87 .75 2.1 2.0 2.1 2.1 1.9 1.8 1.5 1.3 1.5 1.8 1.9 1.8 1.5 1.4 1.9 2.0 2.9 4.1 4.4 54.30 1.75 4.4 .75 108 .18 .20 3.2 2.5 2.4 2.3 2.1 1.8 1.8 1.8 1.8 1.7 1.7 1.6 1.4 1.4 1.4 1.3 1.3 1.5 1.9 2.6 2.6 2.3 2.1 1.9 1.7 1.5 1.4 1.3 1.4 1.3 1.4 56.4 1.82 3.2 1.3 112 .18 .21 1.3 1.2 1.2 1.1 1.4 9.3 224 28 4.3 2.0 1.4 1.2 .99 .76 1.6 349 6387 c58 el. 7 e.93 e4.3 e.89 e5.5 67.5 6.99 e.62 6.43 e.32 6.46 6.26 —— 1097.65 36.6 387 .26 2180 3.66 4.08 , BY WATER YEAR (WY) 1.09 3.07 1992 .28 1990 FOR 1995 1660 4 387 2200 10 3290 6 2 1 5.97 36.6 1992 .086 1994 2.91 10.4 1993 .036 1994 WATER YEAR .33 .55 .00 .00 .85 .00 .45 .18 .0 .1 .33 Sep 17 Oct 3 Oct 8 Sep 7 Sep 7 Oct 1 1.93 7.80 1993 .009 1994 WATER 5 11 1080 15700 17 3840 7 5 1 2.32 6.06 1990 .001 1994 YEARS 1988 .30 .2 .57 Jan .00 Jun .00 Jul Jan . 82 Jan .00 Jun .53 .20 .7 .1 .16 11.5 36.6 1995 .11 1994 - 1995 1991 1994 5 1992 24 1994 21 1994 5 1992 5 1992 22 1994 e Estimated RIO SALINAS BASIN 50100450 RIO MAJADA AT LA PLENA, PR LOCATION.--Lat 18°02'40 M , long 66°12'27 M , Hydrologic Unit 21010004, on right bank, upstream side of bridge on Hwy 712, about 0.3 mi (0.5 km) southwest of La Plena. DRAINAGE AREA.--16.7 mi 2 (43.3 km'). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1973 to April 1979 (montly measurements only), September 1988 to current year. GAGE.--Water-stage recorder. Elevation of gage is 410 ft (125 m), from topographic map. REMARKS.-Records fair except those for estimated daily discharges, which are poor. Some regulation at low flow upstream from station by local residents for agricultural purposes. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 347 OCT JAN JUN JUL AUG 1 e.04 2.0 2 e.02 1.7 3 e.OO 1.6 4 e.OO 1.5 5 e.OO 2.0 6 e.OO 1.9 7 e.02 3.0 8 e.OO 3.0 9 e.OO 2.4 10 e.OO 2.6 11 e.OO 2.9 12 e.OO 2.1 13 e.OO 1.9 14 e.OO 1.8 15 e.OO 1.8 16 e.06 1.7 17 e.30 1.3 18 e.84 1.3 19 e.58 el. 2 20 e.30 el. 2 21 e.16 el. 2 22 e35 el. 2 23 e50 el.l 24 e25 el.O 25 15 el.O 26 9.2 el.l 27 5.8 e.98 28 3.8 e.90 29 3.5 el.O 30 2.9 el.l 31 2.2 — - TOTAL 154.72 49.48 MEAN 4.99 1.65 MAX 50 3.0 HIN .00 .90 AC-FT 307 98 CFSM .30 .10 IN. .34 .11 STATISTICS OF MONTHLY MEAN MEAN 14.5 7.46 MAX 76.4 25.2 (WY) 1991 1991 MIN 1.43 1.53 (WY) 1992 1994 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS e.98 e.78 e.94 e.78 e.68 e.71 e.70 e.58 e.60 e.52 e.62 e.50 e.58 e.50 e.56 e.48 e.45 .47 .52 .52 .57 .50 .63 .60 .66 .63 .59 .79 .70 .59 .49 19.22 .62 .98 .45 38 .04 .04 DATA 3.35 9.67 1991 .62 1995 .46 .40 .44 .45 .52 .44 .36 .33 .34 .40 .36 .30 .37 .39 .28 .33 .43 .30 .30 .25 .27 .30 .25 .26 .28 .40 .81 .49 .45 .42 .24 11.62 .37 .81 .24 23 .02 .03 FOR WATER 11.8 68.8 1992 .37 1995 .14 .14 .19 .18 .21 .19 .19 .29 .49 .51 .43 .34 .26 .22 .24 .23 .38 .44 .52 .44 1.7 3.7 1.8 .82 14 8.3 2.9 1.4 ___ ___ 40.65 1.45 14 .14 81 .09 .09 YEARS 1973 3.45 12.1 1991 .63 1990 1.0 .82 .71 .65 .64 .59 .59 .56 .59 .79 .65 .91 .91 .86 .93 .75 .73 .63 .55 .68 .75 .75 .70 .65 .58 .53 .55 .52 .49 .40 .38 20.84 .67 1.0 .38 41 .04 .05 - 1995 1.78 3.92 1991 .59 1990 FOR 1994 CALENDAR YEAR 353. , 50 . . 701 1. . . 22 97 Oct 23 00 Oct 3 00 Oct 8 058 79 3 35 01 .34 .33 .31 .32 .31 .31 .27 .26 .30 .32 .29 .65 .64 .40 .53 .71 .55 .37 .28 .24 .20 .19 .18 .18 .09 .11 .14 .15 .13 .04 —— 9.14 .30 .71 .04 18 .02 .02 .00 .00 .00 .00 .00 .00 2.8 1.4 .70 .36 .28 .21 .15 .08 .05 .05 .15 .12 .08 .08 .41 .28 .20 .13 .13 .11 .11 .11 .03 .06 .38 8.46 .27 2.8 .00 17 .02 .02 .48 1.7 2.7 .84 .42 .38 .56 .57 .40 .27 .22 .22 .19 .21 .28 .41 .31 .28 .27 .21 .17 .16 .16 .18 .19 .16 .17 .16 .16 .07 ___ 12.50 .42 2.7 .07 25 .02 .03 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .46 .95 .91 .93 .71 .62 9.0 1.6 .81 .61 .44 .66 3.4 2.6 3.9 6.1 33.70 1.09 9.0 .00 67 .07 .08 1.7 1.1 1.1 .81 .74 .44 .38 .39 .43 .34 .24 .22 .20 .14 .08 .08 .08 .35 .88 2.3 1.7 .86 .66 .73 .53 .28 .16 .13 .12 .11 .15 17.43 .56 2.3 .08 35 .03 .04 .19 .18 .39 .34 .31 4.5 el20 el8 e6.0 e3.8 e3.3 e3.0 3.5 1.9 7.0 173 135 46 9.9 6.0 11 6.1 15 16 6.9 4.9 3.9 3.2 4.2 3.0 --- 616.51 20.6 173 .18 1220 1.23 1.37 , BY WATER YEAR (WY) 1.50 3.69 1992 .30 1995 FOR 1995 994 2 173 435 5 1970 2 3 4.60 25.5 1992 .21 1994 WATER YEAR .27 .72 Sep 16 .00 Oct 3 .00 Oct 8 Sep 17 .98 Sep 17 .16 .21 .2 .45 .04 3.61 12.1 1992 .042 1994 3.23 12.9 1993 .17 1994 WATER 5 12 1520 15200 17 4110 4 8 1 2.39 7.74 1992 .010 1994 YEARS 1973 .67 .1 .81 Jan .00 Oct .00 Oct Jan .19 Jan .34 .61 .0 .6 .18 10.1 30.1 1989 .16 1994 - 1995 1992 1994 5 1992 3 1994 8 1994 5 1992 5 1992 e Estimated 348 RIO COAMO BASIN 50106100 RIO COAMO AT COAMO, PR LOCATION.--Lat 18°05'00", long 66°21'16", Hydrologic Unit 21010004, on Highway 14 bridge, 0.8 mi (1.3 km) northeast from Parcjue Atletico, 1.2 mi (1.9 km) southeast from (W.C.P.R.) Antena de Radio. DRAINAGE AREA.--3.5 mi» (112.7 km2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1987 to current year. GAGE.--water-stage recorder and crest-stage gage. Elevation of gage is 335 ft (110 m), from topographic map. REMARKS.--Records poor. Low flow is affected by domestic discharges about 200 ft (65.6 m), upstream from gaging station. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY NOV DEC FEE 1 el. 4 e7.1 2 el. 3 e9.4 3 el. 2 e7.6 4 el.l e6.2 5 el.l e6.4 6 el.l e6.0 7 el. 4 e5.9 8 el. 6 e5.8 9 e76 e5.2 10 e!20 eS.O 11 e56 eS.O 12 eS8 e4.7 13 e!3 e4.8 14 e64 e4.8 IS e46 e4.2 16 e9.2 e4.0 17 e62 e4.0 18 e22 e4.1 19 e20 e4.1 20 e6.2 e4.4 21 eS.9 e4.1 22 e28 e3.9 23 e242 e3.6 24 e39 e3.6 25 e41 e4.6 26 e29 e4.1 27 elS e3.7 28 ell e3.7 29 69.4 e3.6 30 e9.1 e3.7 31 e7.7 —— TOTAL 999.7 147.3 MEAN 32.2 4.91 MAX 242 9.4 MIN 1.1 3.6 AC-FT 1980 292 CFSM .74 .11 IN. .85 .13 STATISTICS OF MONTHLY MEAN MEAN 61.1 27.9 MAX 274 62.9 (WY) 1991 1988 MIN 10.3 4.91 (WY) 1989 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS e3.6 e!3 e7.9 e4.9 e4.2 e3.8 e3.6 e3.3 e3.1 e3.0 e2.9 e2.9 e2.9 e2.9 e3.1 e3.1 e3.1 e3.2 e2.8 e2.9 e2.9 e2.9 e2.9 e3.1 e4.0 e3.7 e3.1 e3.8 e4.0 e3.4 e2.9 116.9 3.77 13 2.8 232 .09 .10 e3.0 e3.1 e3.0 e3.0 e3.0 e3.2 e3.1 e3.0 e2.9 e2.7 e2.6 e2.5 e2.6 e2.6 e2.6 e2.4 e2.2 e2.2 e2.4 e2.5 e2.4 e2.4 e2.5 e2.6 e3.0 e2.7 e2.7 e2.8 e2.8 e2.8 e2.8 84.1 2.71 3.2 2.2 167 .06 .07 DATA FOR WATER 19.0 83.8 1988 3.72 1989 FOR 20.2 79.0 1992 2.71 1995 e3.0 e3.1 e3.1 e3.1 e3.3 e3.6 e3.6 e3.5 e3.7 e3.5 e3.4 e3.6 e3.6 e3.6 e3.6 e3.6 e3.6 e3.6 e3.7 e3.8 e5.7 e4.7 e3.9 e3.8 e96 e34 e!8 e6.3 ___ ___ --- 242.0 8.64 96 3.0 480 .20 .21 YEARS 1987 9.40 17.0 1988 3.17 1989 e4.8 e29 e7.5 e4.9 e4.8 e4.0 e3.5 e3.4 e3.2 e4.9 e7.0 e4.3 e3.5 e3.6 e3.6 e3.1 e2.8 e2.9 e3.5 e3.4 e3.2 e2.9 e2.8 e2.6 e2.6 e2.4 e2.5 e2.2 e2.0 el. 8 e2.0 134.7 4.35 29 1.8 267 .10 .12 - 1995 5.71 9.79 1988 3.09 1987 1994 CALENDAR YEAR 2037. 5. 242 1. 4040 . 1. 5. 2. 1. 98 58 Oct 23 94 Sep 5 1 Sep 5 13 74 8 8 3 el. 9 el. 8 el. 9 el. 8 el. 9 el. 7 el. 7 el. 8 el. 7 el. 9 e2.7 e3.6 e3.2 e3.1 e3.1 e3.4 e4.4 e4.2 e3.2 e2.2 e2.1 e2.2 e2.5 e2.4 e2.1 e2.1 e2.5 e2.5 e2.6 e2.6 —— 74.8 2.49 4.4 1.7 148 .06 .06 e2.6 e2.6 e2.8 e3.0 e4.8 e8.7 e21 e30 eSl e29 e31 elS e9.9 elO e8.4 eS.l e7.2 e6.7 e6.4 e89 e32 e!2 e7.0 e6.3 e6.3 e!3 e63 eSl e!7 e!4 e!4 582.8 18.8 89 2.6 1160 .43 .50 e!2 ell ell elO e9.3 e9.2 e9.1 e8.7 e8.4 eS.l e7.9 e7.6 e7.1 e6.8 e6.8 e6.5 e6.2 e5.9 e5.6 e5.3 eS.l e4.7 e4.3 e4.1 e3.9 e3.6 e!3 e4.5 e3.9 e3.8 —— 213.4 7.11 13 3.6 423 .16 .18 e3.8 e3.6 e3.3 e3.3 e3.3 e3.3 e3.3 e3.3 e3.3 e3.3 e3.2 e3.1 e!3 e7.9 e5.6 e7.5 e5.3 e4.5 e4.4 e3.8 e3.7 e3.6 e3.6 e3.6 e3.6 e3.6 e3.6 e4.0 e4.6 e4.3 e7.3 137.6 4.44 13 3.1 273 .10 .12 8.3 6.8 7.4 6.8 5.9 12 6.9 4.7 4.0 3.8 3.4 3.3 3.3 3.1 3.0 2.8 3.1 6.3 10 9.0 7.2 5.4 6.3 6.0 5.2 .8 .4 .0 .1 .2 3.8 169.3 5.46 12 2.8 336 .13 .14 3.5 3.7 4.2 3.6 4.6 29 32 73 28 18 12 9.9 7.9 6.9 11 199 170 60 29 23 20 17 24 19 16 38 32 28 24 22 968.3 32.3 199 3.5 1920 .74 .83 , BY WATER YEAR (WY) 10.4 27.6 1987 2.49 1995 FOR 1995 3870 10 242 1 1 3180 9 7680 3 23 3 2 17.6 69.6 1992 1.66 1989 WATER YEAR .9 .6 Oct 23 . 1 Oct 4 . 2 Oct 1 Oct 23 .87 Oct 23 .24 .31 .9 .5 16.5 76.1 1987 1.99 1989 7.61 15.5 1988 .78 1989 WATER 18. 36. 4. 1580 51,600 25. 13380 . 5. 35 6. 2. 9.24 23.3 1990 1.28 1994 YEARS 1987 5 8 52 Jan 67 Aug 70 Jul Jan 67 Jan 42 77 7 1 24.6 66.6 1989 1.61 1994 - 1995 1991 1994 5 1992 2 1989 27 1989 8 1992 8 1992 e Estimated RIO COAMO BASIN 50106500 RIO COAMO NEAR COAMO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°03'52", long 66°22'10", Hydrologic Unit 21010004, on Highway 153 bridge, 0 Rio de la Mina, and 1.6 mi (2.9 km) south of Coamo plaza. DRAINAGE AREA.--46.0 mi 1 (119.1 km1 ) . PERIOD OF RECORD.—Water years 1978 to current year. WATER-QUALITY RECORDS, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 349 . 4 mi (0.6 km) above DATE OCT 1994 26. .. DEC 08. . . FEE 1995 17. .. APR 20. .. JUN 14. .. AUG 03. . . DATE OCT 1994 26. .. DEC 06. .. FEE 1995 17. .. APR 20. .. JON 14... ADG 03... TIME 0630 0810 0945 1150 0735 0825 HARD- NESS TOTAL (MG/L AS CAC03) 200 __ __ 250 __ 230 SILICA, DATE OCT 1994 26... DEC 06. .. FEE 1995 17. .. APR 20. . . JUN 14. .. AUG 03. .. K s non-ideal DIS- SOLVED (HO/L AS SIO2) 30 __ __ 29 _- 32 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 32 6.1 3.0 3.2 6.7 6.9 CALCIUM DIS- SOLVED (MG/L AS CA) 52 -- -- 67 -- 59 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 299 -- -- 366 _- 339 SPE- CIFIC CON- DUCT- ANCE (US/CM) 510 612 550 647 612 515 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 16 — -- 21 -- 19 SOLIDS, DIS- SOLVED (TONS PER DAY) 25.5 -- -- 3.35 -- 6.31 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.8 7.6 7.7 7.9 7.6 7.6 SODIUM, DIS- SOLVED (MG/L AS NA) 27 -- -- 34 -- 31 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 10 2 <1 6 4 3 TEMPER- ATURE WATER (DEG C) 24.0 24.0 25.0 26.5 24.0 25.0 SODIUM AD- SORP- TION RATIO o.e — -- 0.9 — 0.9 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.50 0.30 <0.20 <0.20 <0.20 0.29 TUR- BID- ITY (NTU) 4.7 0.60 0.30 1.1 0.20 1.9 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 3.3 -- -- 2.5 -- 2.6 PHOS- PHORUS TOTAL (MG/L AS P) 0.240 0.200 0.170 0.130 0.110 0.140 OXYGEN, DIS- SOLVED (MG/L) 5.2 3.4 3.2 2.4 6.0 4.2 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 240 200 230 250 210 210 ARSENIC TOTAL (UG/L AS AS) 1 -- — <1 — — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 62 40 38 30 71 51 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 -- — — BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 <10 <10 <10 11 <10 SULFATE DIS- SOLVED (MG/L AS S04) 39 -- -- 40 — 33 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 60 -- -- 80 -- -- COLI- FORM, FECAL, 0.45 UM-MP (COLS./ 100 ML) 22000 560 3500 K680 1600 2100 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 34 -- -- 42 -- 36 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 7100 720 660 270 340 2000 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.20 — -- 0.20 -- 0.20 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 — -- <1 -- -- 350 RIO COAMO BASIN 50106500 RIO COAMO NEAR COAMO, PR--Continued WATER-QUALITY RECORDS, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCX 1994 26. .. DEC 08. .. PEB 1995 17. .. APR 20... JUN 14. .. AUG 03... COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) 10 __ — <10 __ -- IRON, TOTAL RECOV- ERABLE (UG/L AS PE) 530 __ __ 180 __ _- LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) <1 __ __ <1 __ __ MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 70 __ __ 70 __ __ MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 — __ <0.20 _ __ SELE- NIUM, TOTAL (UG/L AS SE) <1 __ __ <1 __ __ SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <1 __ __ <1 __ — ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) <10 -- __ <10 __ -_ CYANIDE TOTAL PHENOLS (MG/L TOTAL AS CN) (UG/L) <0.010 <1 __ __ <0.010 1 __ __ METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) 0.02 -- -- 0.02 __ -- RIO DBSCALABRADO BASIN 50108000 RIO DBSCALABRADO NEAR LOS LLANOS, PR LOCATION.--Lat 18°03'08", long 66°25'34", Hydrologic Unit 21010004, at bridge on Highway 14, 1.5 mi (2.4 km) west of Los Llanos, and 5.3 mi (8.5 km) east of Juana Diaz. 351 DRAINAGE AREA.--12.9 mi' (33.4 km'). WATER-DISCHARGE RECORDS PERIOD OP RECORD.—1959-65 (annual low-flow measurements only), 1965 (annual maximum discharge), January 1966 to June 1969, July to December 1969 (maximum discharge only), February 1984 to current year. GAGE.—Water-stage recorder. Elevation of gage is 220 ft (67 m), from topographic map. REMARKS.--Records poor. Some regulation at low flow by local resident upstream from station. DISCHARGE, CUBIC PEST PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT NOV DEC FEE MAR APR MAY JUL ADO SEP 1 .17 e9.0 2 .15 e3.8 3 .13 e2.1 4 .11 el. 3 5 .16 el.O 6 .17 .94 7 .18 .96 8 .14 .80 9 .14 .78 10 .14 .96 11 .14 .74 12 e33 .66 13 e2.7 .60 14 .87 .58 15 .54 .56 16 .10 .56 17 .87 .54 18 25 .66 19 e4.5 .86 20 el. 6 .76 21 el.l .59 22 e4.1 .56 23 e57 .48 24 e26 .33 25 e!6 .29 26 e!2 .21 27 e6.8 .28 28 e3.9 .27 29 e2.5 .24 30 el. 6 .14 31 el. 2 TOTAL 203.01 31.35 MEAN 6.55 1.04 MAX 57 9.0 MIN .10 .14 AC-FT 403 62 CFSM .51 .08 IN. .59 .09 STATISTICS OF MONTHLY MBAN MBAN 28.0 15.2 MAX 117 41.0 (WY) 1986 1985 MIN 2.02 1.04 (WY) 1968 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MBAN HIGHEST ANNUAL MBAN LOWEST ANNUAL MBAN HIGHEST DAILY MBAN LOWEST DAILY MBAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS .11 .31 .49 .21 .13 .11 .09 .07 .07 .07 .05 .05 .04 .04 .05 .03 .05 .06 .04 .11 e.10 .08 .39 .17 1.1 .88 .21 1.3 2.3 .35 .18 9.24 .30 2.3 .03 18 .02 .03 .15 .11 .19 .22 .18 .17 .20 .27 .33 .40 .28 .27 .24 .21 .18 .19 .20 .23 .26 .23 .26 .44 .83 .28 .46 1.0 .51 .40 .41 .34 .32 9.76 .31 1.0 .11 19 .02 .03 DATA FOR WATER 5.22 24.5 1988 .19 1968 FOR 4.96 36.4 1992 .057 1968 .29 .23 e.58 e6.6 .22 e238 .22 .25 .26 .45 .37 .34 .28 .23 .23 .22 .21 .30 .25 .23 .23 .23 .23 .76 .43 .53 .44 384 e276 el. 4 e.74 ___ ___ 669.57 23.9 384 .21 1330 1.85 1.93 YEARS 1966 3.56 23.9 1995 .020 1968 .54 .40 .36 .33 .31 .76 el. 8 e2.8 el.l .62 .47 .47 .44 .38 .35 .33 .30 .20 .46 .63 .65 .71 .74 .95 1.4 2.3 2.0 1.4 268.38 8.66 238 .20 532 .67 .77 - 1995 1.62 8.66 1995 .012 1968 1994 CALENDAR YEAR 583. 1. 67 1160 . 1. 1. 48 60 Apr 6 00 May 24 00 May 24 12 68 3 41 02 .97 .63 .54 .47 .33 .34 .38 .28 .33 .32 .43 1.3 .89 .45 .27 .27 7.4 2.7 .05 .04 .02 .03 .08 .04 .03 .03 .02 .02 .02 .01 ___ 18.69 .62 7.4 .01 37 .05 .05 .01 .01 .01 42 21 4.5 6.9 53 e92 e!25 e42 ell e4.0 e2.1 el. 5 1.6 .66 .45 .32 70 12 3.3 1.6 1.2 1.0 34 12 e!40 e90 e52 e44 869.16 28.0 140 .01 1720 2.17 2.51 e30 e24 e21 e25 29 18 26 18 13 11 4.7 3.2 2.8 2.5 2.4 2.1 1.4 1.1 .89 .73 .74 .40 .25 .21 .15 33 10 6.1 2.8 2.3 292.77 9.76 33 .15 581 .76 .84 1.9 1.3 1.7 1.3 2.3 1.8 1.5 1.4 1.2 .96 .81 .67 .53 .61 .83 22 1.2 1.1 .81 .40 .21 1.5 .23 .16 .12 .11 .74 3.4 4.1 34 7.5 96.39 3.11 34 .11 191 .24 .28 .11 .08 .17 .10 .09 .08 .08 .07 .07 .06 .07 .07 .06 .06 .05 .17 .43 154 e28 e5.0 e3.6 e2.0 el. 8 e2.3 el. 4 el.l el.O e.92 e.88 el. 2 e.76 205.78 6.64 154 .05 408 .51 .59 e.58 e.52 e.50 e.74 e.50 e2.0 e!5 ell e26 e6.0 e3.4 e3.0 e2.4 .45 1.7 136 173 55 40 23 12 6.2 29 27 12 14 16 6.3 6.5 3.2 632.99 21.1 173 .45 1260 1.64 1.83 , BY WATER YBAR (WY) 3.67 18.8 1985 .000 1968 FOR 1995 3307 9 384 2980 9 6560 9 21 15.3 62.2 1985 .032 1968 WATER YEAR .09 .06 Feb 25 .01 Apr 30 .01 Apr 27 Feb 25 .84 Feb 25 .70 .54 .59 .08 5.29 25.2 1987 .000 1967 2.40 10.5 1991 .000 1967 WATER 8 18 1 2600 30000 24 6460 9 13 1 3.57 9.11 1988 .19 1990 YEARS 1966 .92 .4 .69 .00 .00 .37 .69 .40 .3 .04 Oct Jun Jun Oct Oct 12.9 40.2 1985 .063 1967 - 1995 1986 1994 7 1985 22 1966 22 1966 7 1985 7 1985 e Estimated 352 RIO JACAGUAS BASIN 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR LOCATION.--Lat 18°07'37", long 66°27'24", Hydrologic Unit 21010004, on right bank, off a dirt road about 0.3 mi (0.5 km) from road 553, 2.4 mi (3.9 km) southeast from Villalba plaza, and 0.2 mi (0.3 km) downstream from confluence with Quebrada Limon. DRAINAGE AREA.--7.64 mi" (19.79 km"). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--April 1989 to current year. GAGE.--water stage recorder. Elevation of gage is 525 ft (160 m ), from topographic map. REMARKS.—Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT NOV DEC 1 4.0 42 2 3.8 12 3 3.4 9.2 4 3.4 5.4 5 3.3 4.7 6 3.4 4.2 7 4.0 3.8 8 4.5 3.7 9 29 3.4 10 119 3.7 11 54 3.3 12 57 2.9 13 13 2.7 14 63 2.7 15 40 2.7 16 9.1 2.6 17 6.0 2.6 18 22 3.2 19 14 4.0 20 6.1 3.1 21 5.4 2.6 22 28 2.5 23 267 2.3 24 84 2.3 25 81 5.0 26 46 4.2 27 26 3.1 28 14 2.7 29 9.4 2.5 30 7.0 2.5 31 5.3 —— TOTAL 1035.1 151.6 MEAN 33.4 5.05 MAX 267 42 MIN 3.3 2.3 AC-FT 2050 301 CFSM 2.35 .36 IN. 2.71 .40 STATISTICS OF MONTHLY MEAN MEAN 42.6 15.1 MAX 109 40.1 (WY) 1991 1991 MIN 4.61 2.19 (WY) 1992 1992 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 2.3 14 14 5.2 3.6 2.9 2.6 2.4 2.2 2.1 2.1 2.1 2.0 2.1 2.1 2.0 2.7 2.9 2.2 5.8 5.1 3.1 2.9 2.6 4.1 4.3 3.0 3.7 3.0 2.5 2.3 113.9 3.67 14 2.0 226 .26 .30 DATA 6.47 12.4 1993 1.42 1992 2.2 2.1 1.9 1.9 2.0 1.9 1.9 1.8 1.8 1.7 1.9 1.9 2.0 2.0 1.8 1.7 1.7 1.7 1.7 1.6 1.6 1.5 1.6 1.5 2.4 1.8 1.6 1.5 1.6 1.6 1.5 55.4 1.79 2.4 1.5 110 .13 .15 FOR WATER 10.8 43.1 1992 1.79 1995 1.6 1.6 1.6 1.5 1.6 1.8 1.7 1.8 2.1 3.2 1.9 1.7 1.7 1.7 1.6 1.7 1.8 1.8 1.7 1.7 11 5.3 2.6 2.2 37 101 26 5.7 ___ ___ —— 226.6 8.09 101 1.5 449 .57 .59 YEARS 1989 4.50 8.09 1995 2.37 1990 4.1 24 5.1 3.0 2.3 2.0 1.8 1.7 1.7 15 6.1 3.1 2.6 2.7 2.5 2.1 2.0 1.9 1.9 1.9 2.5 2.0 1.8 1.8 1.7 1.7 1.7 1.7 1.7 1.7 1.7 107.5 3.47 24 1.7 213 .24 .28 - 1995 3.37 4.71 1991 1.67 1990 FOR 1994 CALENDAR YEAR 2070. 5. 267 B . 4110 . 5. 5. 2. 1. 97 67 Oct 23 84 Jun 30 97 Jun 29 40 43 8 7 2 1.7 1.7 1.7 1.7 1.7 1.7 1.9 1.9 1.8 1.9 2.5 3.6 2.4 2.1 2.0 6.3 37 4.1 2.7 2.3 2.0 1.9 2.0 2.0 2.0 2.0 2.1 2.3 2.4 2.3 —— 103.7 3.46 37 1.7 206 .24 .27 2.4 2.5 2.8 4.3 13 16 54 234 316 98 26 10 5.4 3.6 8.1 20 15 13 12 303 96 40 25 18 21 74 365 227 140 113 82 2360.1 76.1 365 2.4 4680 5.36 6.18 62 53 60 43 43 34 40 26 17 16 16 17 18 16 12 7.6 7.1 6.6 6.2 6.0 5.9 5.5 5.1 4.9 4.7 8.4 15 13 6.4 5.0 580.4 19.3 62 4.7 1150 1.36 1.52 4.7 4.5 4.0 4.5 5.4 4.7 4.7 4.2 4.3 3.9 3.8 3.5 6.2 5.4 14 40 8.7 6.3 5.5 5.0 4.4 6.0 5.7 5.0 4.8 4.3 4.4 13 11 42 14 257.9 8.32 42 3.5 512 .59 .68 6.6 6.3 6.2 5.2 4.6 30 20 9.5 7.9 7.1 5.7 5.3 6.6 6.8 5.5 4.8 4.8 42 38 28 16 14 18 11 8.6 7.3 6.9 6.8 9.0 5.5 4.6 358.6 11.6 42 4.6 711 .81 .94 4.1 3.9 5.9 4.0 13 115 89 209 49 27 25 18 9.9 8.0 28 447 165 73 37 84 64 45 81 63 40 39 69 56 39 35—— 1945.8 64.9 447 3.9 3860 4.57 5.10 , BY WATER YEAR (WY) 8.25 26.3 1993 1.46 1990 FOR 1995 7296 20 447 1 1 4230 10 1 14470 1 19 47 4 1 23.0 76.1 1995 1.42 1990 WATER YEAR .6 .0 Sep 16 .5 Jan 22 .6 Jan 27 May 20 .04 May 20 . 5 Mar 8 .41 .12 .5 .7 11.8 35.4 1992 1.23 1990 7.28 14.4 1992 .71 1990 WATER 14 20 4 676 8700 13 10290 1 13 33 3 1 7.64 11.9 1989 2.74 1990 YEARS 1989 .2 .0 .02 Jan .45 Aug .61 Jul Jan .24 Jan .44 Aug .00 .59 .9 .3 27.5 64.9 1995 3.21 1994 - 1995 1995 1994 5 1992 7 1990 9 1990 5 1992 5 1992 7 1990 RIO JACAG0AS BASIN 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR—Continued 353 WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1988 to 1995. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: April 198B to September 1995. INSTRUMENTATION.-- Automatic sediment sampler since 1989.. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis and during high flow events EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION! Maximum daily mean, 3,280 mg/L October 23, 1994; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 18,300 tons (16,600 tonnes) January 05, 1992; Minimum daily mean, <0.01 ton (<0.01 tonne) several days. EXTREMES FOR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATION: Maximum daily mean, 3,280 mg/L October 23, 1994; Minimum daily mean, 3 mg/L January 30, April 03-04, 1995. SEDIMENT LOADS: Maximum daily mean, 4,030 tons (3,660 tonnes) May 20, 1995; Minimum daily mean, 0.01 ton (0.01 tonne) January 29, 1995. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN DISCHARGE DAY (CFS) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 4 3 3 3 3 3 4 4 29 119 54 57 13 63 40 9 6 22 14 6 5 28 267 84 81 46 26 14 9 7 5 .0 .8 .4 .4 .3 .4 .0 .5 .1 .0 .1 .4 .4 .0 .3 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) OCTOBER 63 41 26 17 14 14 13 13 175 1730 698 887 145 853 103 24 22 30 25 15 14 132 3280 479 615 71 12 8 7 6 5 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) NOVEMBER . f , 61 2430 272 252 6. 556 17 2. . 38 3940 124 148 10 f t . 68 42 24 16 13 13 14 15 8 59 36 0 96 25 22 83 30 16 11 08 42 12 9.2 5.4 4.7 4.2 3.8 3.7 3.4 3.7 3.3 2.9 2.7 2.7 2.7 2.6 2.6 3.2 4.0 3.1 2.6 2.5 2.3 2.3 5.0 4.2 3.1 2.7 2.5 2.5 ___ 221 54 19 11 10 9 9 6 4 8 23 20 11 7 8 11 14 18 22 21 18 15 13 11 14 15 9 11 20 23 ___ 118 2.6 .48 .17 .12 .11 .09 .06 .03 .08 .20 .16 .08 .05 .06 .08 .10 .16 .25 .18 .12 .10 .08 .06 .25 .18 .08 .08 .13 .16 ___ MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) DECEMBER 2.3 14 14 5.2 3.6 2.9 2.6 2.4 2.2 2.1 2.1 2.1 2.0 2.1 2.1 2.0 2.7 2.9 2.2 5.8 5.1 3.1 2.9 2.6 4.1 4.3 3.0 3.7 3.0 2.5 2.3 17 48 26 14 9 7 6 8 11 11 9 8 7 5 5 6 11 23 16 15 11 7 7 6 12 27 17 20 34 34 30 .11 6.0 1.1 .20 .09 .06 .04 .05 .06 .06 .05 .05 .04 .03 .03 .03 .11 .19 .10 .37 .18 .07 .06 .04 .21 .33 .14 .20 .27 .23 .19 TOTAL 1035.1 7862.71 151.6 124.30 113.9 10.69 354 RIO JACAGUAS BASIN 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAY 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) JAN0ARY 2.2 2.1 1.9 1.9 2.0 1.9 1.9 1.8 1.8 1.7 1.9 1.9 2.0 2.0 1.8 1.7 1.7 1.7 1.7 1.6 1.6 1.5 1.6 1.5 2.4 1.8 1.6 1.5 1.6 1.6 1.5 27 24 21 19 17 15 13 12 10 12 14 17 21 30 44 62 45 26 14 7 8 10 13 9 6 7 10 8 5 3 5 .16 .14 .11 .10 .09 .08 .07 .06 .05 .05 .07 .09 .11 .16 .21 .29 .21 .12 .06 .03 .03 .04 .05 .04 .04 .03 .04 .03 .02 .01 .02 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) FEBRUARY 1.6 1.6 1.6 1.5 1.6 1.8 1.7 1.8 2.1 3.2 1.9 1.7 1.7 1.7 1.6 1.7 1.8 1.8 1.7 1.7 11 5.3 2.6 2.2 37 101 26 5.7 ___ 10 17 25 20 14 10 15 26 19 11 8 6 4 6 11 18 14 12 10 9 34 52 24 14 187 881 49 28 .04 .07 .11 .09 .06 .05 .07 .12 .11 .10 .04 .03 .02 .03 .05 .09 .07 .06 .05 .04 2.2 .80 .18 .08 64 707 5.6 .41 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MARCH 4.1 24 5.1 3.0 2.3 2.0 1.8 1.7 1.7 15 6.1 3.1 2.6 2.7 2.5 2.1 2.0 1.9 1.9 1.9 2.5 2.0 1.8 1.8 1.7 1.7 1.7 1.7 1.7 1.7 1.7 56 177 77 43 28 22 30 41 23 92 103 65 41 28 19 16 13 11 10 33 27 14 11 9 11 13 15 13 9 6 4 .63 42 1.1 .36 .18 .12 .15 .19 .10 17 1.8 .55 .29 .20 .13 .09 .07 .06 .05 .17 .17 .08 .05 .05 .05 .06 .07 .06 .04 .03 .02 TOTAL 55.4 2.61 226.6 781.57 107.5 65.92 RIO JACAGUAS BASIN 355 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1.7 1.7 1.7 1.7 1.7 1.7 1.9 1.9 1.8 1.9 2.5 3.6 2.4 2.1 2.0 6.3 37 4.1 2.7 2.3 2.0 1.9 2.0 2.0 2.0 2.0 2.1 2.3 2.4 2.3 .__ APRIL 4 3 3 11 14 11 8 10 17 27 30 31 31 30 21 19 249 14 11 11 12 13 14 14 12 9 8 9 9 9 .02 .02 .02 .05 .06 .05 .04 .05 .08 .13 .20 .30 .21 .17 .11 .47 130 .16 .08 .07 .06 .07 .07 .08 .06 .05 .05 .05 .06 .06 —— MEAN DISCHARGE (CPS) 2.4 2.5 2.8 4.3 13 16 54 234 316 98 26 10 5.4 3.6 8.1 20 15 13 12 303 96 40 25 18 21 74 365 227 140 113 82 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) MAY 10 10 11 13 23 29 458 1130 1400 298 25 12 11 12 17 30 27 26 24 969 318 78 32 27 38 603 1720 1850 49 94 35 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) JUNE 1 1 180 3010 3030 134 1 1 1 4030 93 9 2 1 2 232 3470 1230 19 32 8 .06 .07 .08 .15 .4 .8 .9 .35 .16 .11 .59 .6 .1 .93 .80 .0 .2 .3 .9 .1 62 53 60 43 43 34 40 26 17 16 16 17 18 16 12 7. 7. 6. 6. 6. 5. 5. 5. 4. 4. 8. 15 13 6. 5.— 6 1 6 2 0 9 5 1 9 7 4 4 0 - 15 11 216 54 72 52 67 15 11 9 8 7 12 25 8 26 35 32 29 26 24 21 19 17 16 21 27 17 10 11 2.5 1.5 84 6.4 11 4.9 12 1.1 .53 .40 .33 .30 .61 1.0 .27 .53 .67 .57 .48 .42 .38 .32 .26 .23 .20 .58 1.7 .76 .18 .15 103.7 132.90 2360.1 15494.60 580.4 134.27 356 RIO JACAGUAS BASIN 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- DISCHARGE THAT ION DAY (CPS) (MG/L) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR 3 3 3 6 5 14 40 8 6 5 5 4 6 5 5 4 4 4 13 11 42 14 257 7296 .7 .5 .0 .5 .4 .7 .7 .2 .3 .9 .8 .5 .2 .4 .7 .3 .5 .0 .4 .0 .7 .0 .8 .3 .4 .9 .6 JULY 12 12 13 13 13 13 12 5 4 5 6 8 12 15 35 167 20 18 16 12 9 9 10 11 12 13 13 47 22 258 19 ... SEDIMENT DISCHARGE (TONS/DAY) MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CPS) (MG/L) (TONS/DAY) AUGUST .15 .15 .14 .16 .19 .16 .16 .05 .04 .05 .06 .07 .34 .23 3.5 74 .47 .30 .23 .16 .10 .15 .16 .15 .15 .15 .15 6.9 .68 181 .89 271.09 32663.81 6 6 6 5 4 30 20 9 7 7 5 5 6 6 5 4 4 42 38 28 16 14 18 11 8 7 6 6 9 5 4 358 .6 .3 .2 .2 .6 .5 .9 .1 .7 .3 .6 .8 .5 .8 .8 .6 .3 .9 .8 .0 .5 .6 .6 16 24 12 4 6 213 50 34 25 19 14 11 8 6 5 4 3 243 57 22 11 7 20 9 8 5 2 3 17 4 3 ... .29 .41 .20 .06 .07 80 2.8 .87 .53 .37 .22 .16 .15 .12 .08 .05 .05 78 6.1 1.7 .48 .29 1.8 .28 .18 .09 .04 .11 .44 .07 .04 176.05 MEAN DISCHARGE (CPS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) SEPTEMBER 4.1 3.9 5.9 4.0 13 115 89 209 49 27 25 18 9.9 8.0 28 447 165 73 37 84 64 45 81 63 40 39 69 56 39 35 1945.8 4 4 12 6 49 426 627 1420 71 37 72 26 23 21 153 1810 1570 1390 790 995 332 77 538 299 20 85 366 216 16 4 ... .04 .04 .20 .06 7.6 209 183 1380 9.9 2.7 7.3 1.3 .61 .45 32 3650 763 283 82 435 63 9.5 238 59 2.3 16 134 36 1.7 .40 7607.10 RIO JACAGUAS BASIN 357 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR--Continued HATER QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DATE OCT 1994 10. .. MAY 1995 08.. . 09.. . 27.. . DATE OCT 1994 10.. . HAY 1995 08.. . 09... 27.. . TIME 1245 1835 1615 1715 SED. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 81 55 62 59 DIS- CHARGE, INST. CUBIC FEET PER SECOND 420 2190 1120 844 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM 87 67 75 72 SEDI- MENT, SUS- PENDED (MG/L) 6547 7209 6392 3293 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 97 78 92 84 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 7420 42600 19300 7500 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 99 89 98 95 SED. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 48 31 37 31 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 99.2 96 99.6 99.3 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 51 41 44 40 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99.6 99 99.8 99.7 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 66 47 50 46 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 99.9 99.6 99.9 99.9 358 RIO JACAGUAS BASIN 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR—Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DATE OCT 1994 10... 11.. . 12.. . 14.. . 23.. . 24.. . FEB 1995 26... 26... MAY 09.. . 09... 09... 09.. . 08.. . 20... 20.. . 26... 27.. . SEP 06.. . 16... TIME 1400 1625 1400 1910 0935 1612 1455 1650 1615 1630 1715 1745 1810 1630 1650 1445 1730 1650 1330 STREAM- FLOW, INSTAN- TANEOUS (CFS) 1100 176 142 344 224 61 631 317 1120 987 914 959 2580 641 571 98 896 190 469 SEDI- MENT, SUS- PENDED (MG/L) 12900 8780 3590 4770 3950 95 6860 3650 3600 3600 4220 3760 6080 894 917 999 2750 307 762 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 38300 4170 1380 4430 2390 16 11700 3120 10900 9590 10410 9740 42400 1550 1410 264 6650 157 965 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 78 97 93 97 95 88 85 98 90 90 88 91 65 93 93 92 87 88 90 RIO JACAGUAS BASIN 359 50111300 LAGO GUAYABAL AT DAHSITE NEAR JUANA DIAZ, PR LOCATION.—Lat 18«05'17", long 66°30'09", Hydrologic Unit 21010004, at Damsite, 2.30 ml (3.70 km) northeast from Juana Dfaz plaza, 0.70 mi (1.13 km) northeast from Eacuela Salvador Bousquets and 2.45 mi (3.94 km) southeast from Escuela Zoilo Gracia. DRAINAGE AREA.--21.0 mi 1 (54.4 km 1 ). ELEVATION RECORDS PERIOD OF RECORD.—April 1995 to September 1995. GAGE.—Water stage recorder. Datum of gage is mean sea level. REHARKS.--Lago Guayabal was completed in 1913. The dam is a reinforced concrete, flatslab and buttress-type structure about 130 ft (40 m) height, a net crest lenght at the right side of the dam of 693 ft (211 m) and a crest elevation of 331 ft (101 m) . It has a maximum storage capacity of 7,600 acre-feet (9.37 hm3 ). The Guayabal Dam is owned by the Puerto Rico Electric Power Authority (P.R.B.P.A) and its primary purpose is for irrigation of lands served by the Juana Diaz Canal. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR CURRENT PERIOD.--Maximum elevation, 341.25 ft (104.0 m), Hay 27; minimum elevation, 334.67 ft (102.0 m), Hay 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 305 366 330 3,885 321 2,010 341 7,360 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES I OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX MIN 336 336 335 335 335 335 335 335 335 335 334 .41 .24 .89 .57 .47 .40 .41 .39 .39 .13 .87 --- ___ 334. 334. 334. 334. 335. 335. 336. 337. 338. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 334. 83 80 80 84 28 61 68 63 98 48 70 86 77 67 82 85 79 80 80 29 33 48 58 59 86 92 93 90 85 87 82 93 80 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 339. 339. 339. 340. 340. 340. 340. - 340. 339. 84 83 83 77 77 80 85 79 75 76 73 75 72 70 67 61 45 31 28 25 20 18 14 96 82 88 13 28 27 25 -- 85 82 340. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 339. 340. 340. 340. 339. 09 93 88 74 70 67 60 45 30 26 20 15 26 27 23 34 34 49 64 75 89 87 90 86 70 61 45 50 66 33 48 48 15 340 340 340 340 340 340 340 340 340 339 339 339 339 339 339 339 339 340 340 340 340 340 340 340 340 340 340 340 340 340 340 340 339 .45 .49 .46 .41 .24 .15 .17 .13 .06 .99 .91 .72 .54 .49 .43 .55 .68 .98 .90 .96 .90 .87 .89 .87 .87 .80 .79 .86 .86 .86 .85 .98 .43 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 340. 341. 340. 340. 340. 340. 340. 340. 340. 341. 340. 340. 340. 340. 340. 340. 340. - 341. 340. 85 79 77 77 81 94 98 85 77 70 90 87 81 81 02 95 97 90 92 99 92 91 01 90 87 98 93 87 84 81 -- 02 70 360 RIO JACAGUAS BASIN 50111500 RIO JACAGUAS AT JUANA DIAZ, PR LOCATION.--Lat ie°03'16" r long 66°30'40 B , Hydrologic Unit 21010004, on Highway 14 bridge, 0.4 mi (0.6 km) weet of Juana Diaz plaza, and 4.0 mi (€.4 km) downstream from Lago Guayabal. DRAINAGE AREA.--49.6 mi 1 (129.0 km'). WATER-DISCHARGE RECORDS PERIOD OF RECORD.—March 1964 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 131 ft (40 m), from topographic map. REMARKS.--Records poor. Flow regulation from Lago Guayabal. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY DEC JAN APR MAY JUN JUL AUG SEP 1 1.3 5.1 2 1.2 5.6 3 .96 6.2 4 .84 6.0 5 .55 7.2 6 .41 €.6 7 .57 6.6 6 1.2 6.6 9 1.1 6.7 10 1.2 7.1 11 1.5 6.6 12 1.3 6.6 13 1.2 6.8 14 1.1 7.3 15 1.3 7.3 16 1.2 7.2 17 1.3 7.4 18 1.6 7.7 19 4.3 6.4 20 3.2 8.4 21 2.5 6.6 22 13 6.7 23 5.6 6.7 24 20 6.4 25 23 6.6 26 11 6.7 27 7.2 6.4 26 6.6 6.3 29 6.2 6.1 30 5.5 6.6 31 5.4 —— TOTAL 133.73 227.1 MEAN 4.31 7.57 MAX 23 8.7 MIN .41 5.1 AC-FT 265 450 CFSH .09 .15 IN. .10 .17 9.0 9.3 9.1 6.7 6.2 7.7 7.7 7.7 7.7 8.2 6.4 6.2 8.0 6.0 7.6 7.4 7.5 7.9 7.9 6.6 5.9 5.6 5.6 6.0 6.3 6.1 6.0 6.2 6.3 5.7 5.7 226.6 7.31 9.3 5.6 449 .15 .17 STATISTICS OF MONTHLY MEAN DATA MEAN 128 94.6 MAX 445 267 (WY) 1986 1986 MIN 4.31 7.57 (WY) 1995 1995 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 37.9 151 1968 7.31 1995 FOR 5.5 5.2 5.1 5.3 5.0 .7 .9 .6 .7 .7 .5 .3 .0 .0 3.7 3.4 3.4 3.4 3.4 3.2 3.1 3.4 3.3 3.0 3.0 3.1 2.6 2.2 2.1 2.0 1.9 116.9 3.77 5.5 1.9 232 .08 .09 1.9 1.9 1.6 1.9 1.9 1.9 2.0 2.2 2.0 1.5 1.3 1.2 1.3 1.3 1.3 1.4 1.3 1.3 1.3 1.1 1.5 1.6 1.7 1.3 6.4 120 20 5.6 ___ ___ --- 192.3 6.87 120 1.1 361 .14 .14 FOR WATER YEARS 1964 26.2 144 1992 3.77 1995 6.38 16.9 1991 1.97 1994 .5 .3 .6 .5 .4 .2 .0 3.9 3.7 3.6 5.5 3.6 3.5 3.5 3.4 3.2 2.6 3.1 3.5 3.4 3.2 3.3 3.4 3.1 2.6 2.5 2.4 2.6 2.9 2.7 2.4 106.9 3.51 5.5 2.4 216 .07 .08 - 1995 4.64 7.94 1966 1.95 1994 1994 CALENDAR YEAR 1071.27 2.93 23 .41 .61 2120 .059 .60 7.6 1.7 .76 Oct 25 Oct 6 Jun 29 2.2 2.2 2.2 2.2 2.0 2.2 2.2 2.3 2.2 2.3 2.6 3.6 2.5 2.2 2.0 2.2 6.0 5.9 3.4 3.2 3.0 2.6 2.6 2.6 2.5 2.4 2.3 2.3 2.2 2.3 --- 61.0 2.70 6.0 2.0 161 .05 .06 2.5 2.6 2.5 6.6 4.2 3.6 3.4 4.3 4.2 5.9 8.0 6.2 7.9 7.7 7.0 6.4 5.5 5.0 4.7 11 6.0 6.1 6.0 6.3 6.4 66 367 346 106 79 67 1201.2 36.7 367 2.5 2360 .78 .90 51 46 41 41 27 24 26 36 24 20 16 17 e!9 e!6 e!6 e!7 e!6 e!5 e!4 e!4 e!3 e!2 ell e21 e!8 e20 e!2 e6.2 7.3 7.4 —— 633.9 21.1 51 7.3 1260 .42 .47 7.4 7.4 7.2 6.6 6.2 5.7 5.9 5.6 5.1 4.6 4.6 4.7 6.1 6.0 4.2 4.7 4.4 4.6 4.4 4.4 4.6 5.3 5.2 4.7 5.0 4.6 5.0 6.2 8.9 6.2 7.3 175.2 5.65 6.9 4.2 346 .11 .13 e7.5 e6.8 7.1 6.6 6.8 6.5 5.7 5.5 5.7 6.0 6.0 6.2 6.4 6.0 5.6 23 9. 0 36 59 69 76 63 56 44 43 38 21 21 34 34 32 756.8 24.4 76 5.5 1500 .49 .57 32 27 20 20 21 33 36 50 47 32 26 33 29 26 27 27 27 25 25 24 24 23 21 21 20 19 16 16 17 17 --- 787 26.2 50 17 1560 .53 .59 , BY WATER YEAR (WY) 9.57 34.7 1992 1.64 1994 FOR 1995 4640. 12. 387 . , 3720 12. 9200 3. 27 5. 1. 72.8 215 1965 1.46 1994 WATER YEAR 63 7 May 27 41 Oct 6 60 Oct 3 May 27 52 May 27 26 47 9 9 42.3 196 1967 .93 1994 22.4 62.4 1967 1.04 1994 WATER 43. 60. 6. 4530 . . 40000 29. 31210 . 11. 95 7. 2. 19.6 41.1 1965 1.59 1994 YEARS 1964 - 1 9 23 Nov 27 24 Jan 3 61 Jun 29 Oct 7 42 Oct 7 67 75 6 4 34.8 164 1965 1.07 1994 1995 1986 1994 1967 1992 1994 1965 1985 e Estimated lv\ \\ ] j )y \\ \ \ w- / / r-) ^\ \ ,., ,", / '-^ / ] K./ / i '-"" ^ V' EXPLANATION SURFACE-WATER STATION AND NUMBER yn62 QUALITY-OF-WATER STATION AND NUMBER 132 WELL AND WELL NUMBER 125780 LAKE-ELEVATION STATION AND NUMBER Figure 24.--South coast river basins the Rio Inabon to Rfo Loco basins. O) 362 RI° INABON BASIN 50112500 RIO INABON AT REAL ABAJO, PR LOCATION.—Lat 18°05'10", long 66°33'46", Hydrologic Unit 21010004, at bridge on private road, off Highway 511 at Hacienda La Concordia, 0.4 mi (0.6 km) upstream from diversion canal, 0.5 mi (0.8 km) north of Real Abajo, and 6.1 mi (9.8 km) northeast of Plaza Degetau in Ponce. DRAINAGE AREA.--9.70 mi' (25.12 km9 ). HATER-DISCHARGE RECORDS PERIOD OF RECORD.—1962-63 (annual low-flow measurements only), February to June 1964 (monthly measurements only), July 1964 to July 1970, April 1971 to current year. GAGE.—Water-stage recorder. Elevation of gage is 410 ft (125 m) , from topographic map. Prior to April 1971 nonrecording gage and crest-stage gage at different datum. REMARKS.--Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY NOV JAN FEB APR JUN JUL SEP 1 24 31 2 16 39 3 14 39 4 12 28 5 11 24 6 15 24 7 16 24 8 101 22 9 44 30 10 26 27 11 24 23 12 24 20 13 17 18 14 14 17 15 13 16 16 11 15 17 17 13 18 26 12 19 19 11 20 16 11 21 20 9.6 22 32 9.7 23 45 11 24 67 9.9 25 64 11 26 38 9.1 27 32 6.6 28 28 8.4 29 25 6.8 30 23 7.3 31 22 —— TOTAL 856 533.4 MEAN 27.6 17.8 MAX 101 39 MIN 11 6.6 AC-FT 1700 1060 CFSM 2.85 1.83 IN. 3.28 2.05 7.5 8.6 7.9 9.7 7.1 6.1 6.0 5.8 5.0 4.8 5.3 4.9 5.0 5.2 5.0 4.8 5.1 5.2 4.8 4.4 4.8 4.6 7.1 5.9 8.4 7.5 6.8 6.2 4.8 4.1 3.6 182.0 5.87 9.7 3.6 361 .61 .70 STATISTICS OF MONTHLY MEAN DATA MEAN 46.7 34.0 MAX 148 77.9 (WY) 1986 1978 MIN 14.5 8.32 (WY) 1994 1977 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 12.4 26.5 1966 4.43 1977 FOR 3.4 3.5 3.5 3.5 3.3 3.2 3.3 3.4 3.7 4.2 4.0 4.5 5.3 4.6 3.9 4.4 5.6 6.4 4.8 4.2 4.1 5.2 5.5 5.3 6.9 5.9 6.6 5.9 6.1 5.9 5.6 145.7 4.70 6.9 3.2 289 .48 .56 FOR WATER 8.57 45.5 1992 4.11 1989 4.9 5.9 5.5 5.0 5.0 5.2 5.2 7.6 6.8 6.1 5.3 .9 .8 .6 .4 .2 .7 .3 .1 .9 12 13 12 9.6 8.9 44 18 12 —— 232.9 8.32 44 4.1 462 .86 .89 YEARS 1964 5.49 9.25 1992 3.05 1977 20 20 14 14 12 8.0 7.3 5.7 5.0 6.1 7.9 5.0 5.0 4.7 4.4 4.9 4.7 4.4 4.6 4.7 4.7 4.4 3.5 4.1 3.7 3.9 3.8 4.7 4.7 4.9 4.4 209.2 6.75 20 3.5 415 .70 .80 - 1995 5.68 16.4 1972 1.85 1977 1994 CALENDAR YEAR 3249. 8. 101 1. 1. 6450 . 12. 21 5. 2. 5 90 Oct 8 2 Jul 24 9 Jun 20 92 46 2 4 4.3 4.1 4.1 5.0 5.3 4.9 4.4 3.9 4.2 4.7 6.3 8.7 6.9 4.7 5.9 7.1 49 19 12 8.0 6.1 5.4 .9 .8 .6 .2 .1 .4 .7 .3 — - 220.0 7.33 49 3.9 436 .76 .84 4.3 3.8 3.5 5.1 28 24 26 31 79 21 7.1 5.1 4.7 4.0 7.5 8.9 7.0 6.1 6.6 6.8 5.7 6.5 5.9 5.7 14 10 9.7 8.5 5.8 6.2 5.3 372.8 12.0 79 3.5 739 1.24 1.43 4.4 3.9 4.7 6.6 7.1 7.0 6.4 6.6 5.8 9.2 11 8.2 7.1 6.6 6.3 6.5 5.7 5.1 5.2 5.4 5.8 5.7 5.4 5.2 5.1 5.3 14 14 7.1 5.8 202.2 6.74 14 3.9 401 .69 .78 5.9 5.2 5.0 5.3 6.9 7.3 8.2 6.6 6.6 7.1 6.1 5.4 5.1 5.4 14 13 7.3 6.1 4.7 4.8 5.5 7.6 7.0 8.1 5.9 5.4 4.4 7.7 10 32 17 246.6 7.95 32 4.4 489 .82 .95 6.5 5.9 6.5 6.2 6.4 8.5 8.1 6.2 5.9 6.4 6.5 5.5 5.5 5.6 7.7 24 7.3 60 68 24 15 13 13 12 12 11 11 14 13 12 11 417.7 13.5 68 5.5 829 1.39 1.60 12 11 14 13 17 61 71 40 27 20 35 27 21 17 20 183 118 68 50 39 34 31 32 30 26 24 25 23 21 20 1130 37.7 183 11 2240 3.88 4.33 , BY WATER YEAR (WY) 8.05 19.2 1992 2.76 1975 FOR 1995 4748 13 183 3 3 746 8 9420 1 18 27 6 4 19.7 76.7 1969 1.94 1967 WATER YEAR .5 .0 Sep 16 . 2 Jan 6 . 4 Jan 1 Oct 8 .73 Oct 8 .34 .21 .6 .3 15.9 49.8 1969 2.75 1967 11.9 32.7 1979 1.77 1990 WATER 18 30 7 2500 1 19000 25 13060 1 25 40 8 3 17.0 46.1 1979 4.47 1974 YEARS 1964 - .0 .9 .44 Sep 16 .80 Jul 23 .1 Mar 31 Oct 7 .30 Oct 7 .86 .25 .9 .2 32.4 119 1975 7.70 1986 1995 1969 1994 1975 1977 1977 1985 1985 RIO BUCANA BASIN 50113800 RIO CERRILLOS ABOVE LAGO CERRILLOS NEAR PONCE, PR LOCATION.--Lat 18°07'01", long 66°36'17'', Hydrologic Unit 21010004, on right bank, 0.3 mi (0.5 km) downstream from confluence with Rio San Patricio, 0.1 mi (0.2 km) southwest of Hwy 139 and 2.4 mi (3.7 km) northwest of Haragiiez. DRAINAGE AREA.-- 15.4 mi 2 (39.9 km 2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 720 ft (210 m), from topographic map. REMARKS.—Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 363 OCT NOV JAN JUL SEP 1 35 31 2 17 69 3 13 66 4 11 34 5 9.4 25 6 10 26 7 13 21 8 148 18 9 72 29 10 35 20 11 26 17 12 21 15 13 16 14 14 14 13 15 14 13 16 12 12 17 21 12 18 48 12 19 23 12 20 18 12 21 59 11 22 76 11 23 97 10 24 116 9.9 25 121 11 26 69 11 27 41 23 28 30 14 29 24 11 30 20 10 31 19 —— TOTAL 1248.4 592.9 MEAN 40.3 19.8 MAX 148 69 MIN 9.4 9.9 AC-FT 2480 1180 CFSM 3.38 1.66 IN. 3.90 1.85 STATISTICS OF MONTHLY MEAN MEAN 75.3 32.2 MAX 154 59.3 (WY) 1991 1993 MIN 24.6 9.77 (WY) 1992 1994 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN- DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 9.1 9.3 12 12 9.5 9.0 8.6 8.3 8.1 8.1 8.2 8.1 7.9 7.4 7.3 7.3 8.0 7.7 7.3 7.3 7.3 7.1 8.0 7.4 9.8 7.9 7.4 7.3 6.2 6.2 5.9 251.0 8.10 12 5.9 498 .68 .78 DATA 15.5 26.2 1993 8.10 1995 FOR 6.1 6.2 6.2 6.5 6.2 6.2 5.9 5.6 5.7 5.9 5.5 5.2 5.4 5.2 22 11 6.5 6.3 5.8 5.5 5.5 6.5 6.7 5.5 6.4 6.8 6.7 5.8 5.5 5.2 4.9 204.4 6.59 22 4.9 405 .55 .64 FOR WATER 17.5 59.0 1992 6.59 1995 4.9 4.9 4.8 4.6 4.6 4.6 4.8 6.1 4.9 5.7 .7 .6 .6 .6 .6 .6 .7 .5 4.5 5.1 34 14 56 21 64 142 54 43 ___ —— 524.4 18.7 142 4.5 1040 1.57 1.64 YEARS 1989 10.5 18.7 1995 6.34 1990 34 28 26 24 14 11 9.5 8.8 9.7 33 42 21 16 13 11 10 9.6 9.1 9.1 8.6 8.6 8.2 8.4 8.0 7.3 7.3 6.7 6.4 6.6 6.4 6.2 427.5 13.8 42 6.2 848 1.16 1.34 - 1995 11.5 27.5 1989 4.77 1990 1994 CALENDAR YEAR 4273. 11. 148 3. 3. 8480 . 13. 23 5. 3. 9 7 Oct 8 0 Jul 6 2 Jul 27 98 36 8 5 6.1 5.9 5.9 5.6 5.2 5.1 4.8 5.2 5.2 4.8 7.7 11 4.8 4.4 4.9 5.0 92 25 6.9 5.0 4.6 5.3 .9 . • .1 .2 —— 265.6 8.85 92 4.1 527 .74 ,83 4.4 4.1 8.9 11 54 36 46 62 57 36 14 9.0 7.0 6.0 55 35 16 13 12 16 12 9.7 8.6 8.4 12 14 96 62 27 43 36 831.1 26.8 96 4.1 1650 2.25 2.60 24 19 20 43 75 59 32 24 25 42 29 22 19 17 17 16 14 14 13 13 12 12 11 11 12 14 40 24 14 12 ___ 699 23.3 75 11 1390 1.96 2.19 12 11 10 9.8 9.8 16 12 10 9.6 9.1 9.4 9.8 9.1 9.4 52 43 15 12 11 10 10 11 15 12 9.4 8.6 8.6 31 17 86 52 550.6 17.8 86 8.6 1090 1.49 1.72 19 15 13 11 10 16 13 11 10 9.5 9.1 8.7 8.4 13 14 89 28 167 256 122 86 55 33 24 20 15 12 82 60 21 15 1265.7 40.8 256 8.4 2510 3.43 3.96 12 9.9 9.4 8.0 12 104 151 85 39 22 76 50 24 15 51 517 204 120 137 100 63 59 99 82 67 58 60 49 41 36—— 2360.3 78.7 517 8.0 4680 6.61 7.38 , BY WATER YEAR (WY) 14.1 24.3 1989 6.38 1990 FOR 1995 9220 25 517 4 4 1710 5 18290 2 28 61 12 5 26.5 68.2 1993 4.58 1990 WATER YEAR .9 .3 Sep 16 .1 Apr 29 .3 Apr 26 Sep 16 .25 Sep 16 .12 .82 .1 21.8 36.5 1989 6.37 1990 14.5 26.7 1991 3.37 1994 WATER 25 35 9 717 3 3 8140 9 18770 2 29 59 13 4 27.4 53.1 1991 11.3 1994 YEARS 1989 .9 .7 .94 Jan .0 Jul .2 Jul Jan . 65 Jan .18 .58 .8 51.0 88.0 1989 16.9 1994 - 1995 1993 1994 6 1992 6 1994 27 1994 5 1992 5 1992 364 RIO BUCANA BASIN 50114000 RIO CERRILLOS NEAR PONCE, PR LOCATION. —Leit 18°04'15", long 66°34'51", Hydrologic Unit 21010004, on right bank off Highway 139, 0.9 mi (1.3 km) below Lago Cerrillos Dam, 2.3 mi (3.7 km) upstream from Quebrada Ausubo and 4.6 mi (7.4 km) northeast of Plaza Degetau in Ponce. DRAINAGE AREA. --17.9 mi3 (46.1 km3 ), excludes 17.4 mi2 (45.1 km3 ), upstream from Lago Cerrillos Dam. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February to April 1964 (monthly measurements only), May 1964 to June 1995, July 1995 to April 1991 (semi-monthly measurements only). May 1991 to current year. GAGE.—Water-stage recorder. Datum of gage is 253.10 ft (77.145 m), above mean sea level, at site 0.15 mi (0.24 km) upstream and datum 9.90 ft (3.019 m) higher. Prior to March 22, 1977 REMARKS.--Records poor. Flow regulated by Lago Cerrillos Dam since May 1991. Gage-height and precipitation satellite telemetry at station. Prior to June 1995 some low-flow regulation by construction upstream. Maximum discharge prior to regulation, 22,400 ft'/s (6.34 m'/s). Sept. 16, 1975, gage-height, 11.2 ft (3.414 m) , site and datum then in use from floodmarks, from rating curve extended above 150 ft'/s (4.25 m'/s), on basis of slope area measurements of peak flow; minimum discharge prior to regulation, 2.2 ft'/s (0.062 m'/s). May 29, 1967. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT FEB MAR APR AUG SEP 1 6.9 5.1 4.9 2 6.6 5.1 5.0 3 6.4 5.9 5.3 4 6.2 7.2 5.2 5 6.1 5.3 5.1 6 5.9 5.1 5.0 7 5.9 5.1 .9 9 6.2 5.2 .9 9 6.1 5.3 .7 10 5.9 5.5 .7 11 5.5 5.5 .7 12 5.6 5.5 .9 13 5.4 5.6 .9 14 5.4 5.7 .7 15 5.4 5.7 .6 16 5.3 5.9 .5 17 6.3 6.0 .6 19 6.2 6.0 .6 19 5.5 6.1 .5 20 5.9 6.0 .6 21 5.6 5.9 .7 22 7.7 5.7 .9 23 6.3 5.5 .6 24 7.3 5.4 .5 25 6.7 5.6 .9 26 5.9 5.5 .9 27 5.4 5.3 .7 29 5.2 5.3 .9 29 5.3 5.3 5.1 30 5.1 5.0 5.0 31 5.3 —— 4.9 TOTAL 194.2 167.3 149.1 MEAN 5.94 5.59 4.91 MAX 7.7 7.2 5.3 MIN 5.1 5.0 4.5 AC-FT 365 332 296 CFSM .33 .31 .27 IN. .39 .35 .31 STATISTICS OF MONTHLY MEAN DATA MEAN 27.9 15.0 10.5 MAX 42.5 32.3 16.9 (WY) 1993 1993 1993 MIN 5.94 5.59 4.91 (WY) 1995 1995 1995 SUMMARY STATISTICS FOR ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGS ANNUAL RUNOFF (AC- FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS .9 .7 .9 .9 .9 5.0 5.1 5.1 5.1 4.9 4.9 4.9 4.9 4.9 5.0 5.3 5.7 5.7 5.4 5.3 5.3 5.1 5.1 5.1 5.1 5.3 6.0 6.1 6.1 6.1 5.9 162.3 5.24 6.1 4.7 322 .29 .34 FOR WATER 22.9 74.2 1992 4.52 1993 5.9 6.3 4.9 5.9 5.2 5.2 5.7 5.1 5.7 5.7 4.9 5.7 5.7 5.0 5.1 5.5 5.0 5.3 5.6 5.2 5.5 6.0 5.1 5.5 5.7 5.4 5.6 5.6 5.7 5.4 5.3 5.4 9.2 5.5 5.1 7.9 5.4 5.2 7.3 5.3 5.4 6.1 5.1 5.3 6.3 5.7 5.7 5.4 5.3 5.2 6.7 5.7 6.2 5.7 6.9 12 6.5 6.5 .9 6.5 .9 11 .9 5.6 .9 5.5 .0 5.1 .0 5.1 .9 5.1 .9 5.1 .7 5.3 .7 5.4 .7 5.4 .6 5.5 .9 5.9 —— 5.1 5.7 —— 5.1 5.6 4.9 167.3 157.1 179.4 5.97 5 07 5.95 12 6.3 11 5.1 4.6 4.9 332 312 354 .34 .35 29 .33 33 .37 YEARS 1991 - 1995, BY WATER 7.97 6 99 10.7 14.7 10.6 24.6 1992 1992 1992 4.37 5 07 5.51 1993 1995 1994 1994 CALENDAR YEAR 2207. 6. 17 4. 4. 4390 . 4. 7. 5. 5. 0 05 Sep 20 5 Dec 16 6 Dec 14 34 61 2 6 1 5.3 5.2 5.3 5.4 5.5 5.6 7.9 7.3 6.1 5.6 5.4 5.1 .9 .6 .9 .9 .2 .4 .5 5.4 5.0 5.1 5.1 5.3 6.4 5.5 5.2 5.4 5.0 5.0 4.6 164.9 5.32 7.9 4.2 327 .30 .34 YEAR (WY) 31.9 77.7 1993 5.32 1995 .4 .5 .6 .4 .1 .1 .1 .2 3.9 3.9 3.7 3.6 3.6 3.5 3.5 3.2 3.1 3.1 3.1 3.1 3.2 3.2 3.2 3.2 3.3 3.6 3.7 3.9 3.9 4.0 110.7 3.69 4.6 3.1 220 .21 .23 19.1 33.7 1992 3.69 1995 FOR 1995 WATER YEAR 1951.1 5.35 40 3.1 3.1 266 4.14 3970 .30 4.09 6.2 5.1 4.1 Sep 16 Jun 17 Jun 16 Aug 19 Aug 19 .0 .1 .2 .3 .5 .6 .7 .9 5.0 5.1 5.9 5.6 5.5 5.1 5.6 5.9 .9 .7 .6 .5 .2 .7 .4 .1 .1 .9 .0 .4 5.4 5.1 5.1 147.1 4.75 5.9 3.9 292 .27 .31 14.5 24.6 1991 4.75 1995 WATER 16. 29. 5. 900 . 1. 1100 6. 12020 12. 33 6. 4. .9 .7 .7 .6 .6 .0 .4 .3 .2 .0 3.9 3.6 3.7 3.6 3.6 6.2 3.9 6.4 19 e9.1 e6.1 e5.6 e5.9 e5.2 e4.9 e4.9 e5.0 e5.3 e5.0 e4.6 e4.4 163.1 5.26 19 3.6 324 .30 .34 16.2 24.6 1993 5.26 1995 YEARS 1991 - 6 6 35 Jan 6 64 Aug 19 7 Aug 24 Jan 6 07 Jan 6 93 67 9 4 e4.4 e4.7 e4.7 e5.0 e4.9 e5.1 e6.4 e5.5 e5.6 e6.0 e6.3 e6.3 e6.1 e6.3 e6.9 e40 e5.4 e4.9 e6.5 e5.6 e5.5 e5.3 e5.9 e6.3 e6.2 e5.6 e5.0 e4.7 e4.5 e4.1 199.6 6.65 40 4.1 396 .37 .42 14.7 31.5 1992 6.65 1995 1995 1992 1995 1992 1992 1992 1992 1992 RIO BUCANA BASIN 50114000 RIO CERRILLOS NEAR PONCE, PR--Continued WATER-QUALITY RECORDS Location.--Lat ie°04'15", long 66°34'51", Hydrologic unit 21010004, on right bank off Highway 139, 2.3 mi (3.7 km) upstream from Quebrada Ausubo and 4.6 mi (7.4 km) northeast of Plaza Degetau in Ponce. DRAINAGE AREA.--17.8 mi 1 (46.1 km3 ) PERIOD OP RECORD.--Water years 1964 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 365 DATE OCT 1994 27. . . DEC 23. . . PEB 1995 22. .. APR 27. . . JUN 16. .. AU6 22. .. DATE OCT 1994 27. .. DEC 23. .. PEB 1995 22. .. APR 27. .. JUN 16. .. AU6 22. .. DATE OCT 1994 27. .. DEC 23... FEB 1995 22. .. APR 27. .. JUN 16. .. AU6 22. .. TIME 1200 1040 1015 1025 0905 0835 HARD- NESS TOTAL (MG/L AS CAC03) 170 -- -- 160 -- 170 SILICA, DIS- SOLVED (HG/L AS SIO2) 24 -- -- 23 -- 24 DIS- CHARGE, INST. CUBIC PEET PER SECOND 5.5 4.9 5.5 5.1 3.1 6.0 CALCIUM DIS- SOLVED (MG/L AS CA) 56 -- -- 52 -- 56 SOLIDS, SUM OP CONSTI- TUENTS, DIS- SOLVED (MG/L) 258 -- -- 230 -- 266 SPE- CIFIC CON- DUCT- ANCE (US /CM) 403 372 365 379 365 418 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 6.1 — -- 6.3 __ 6.6 SOLIDS, DIS- SOLVED (TONS PER DAY) 3.80 -- -- 3.19 -- 4.29 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.7 7.4 8.2 7.4 7.5 7.4 SODIUM, DIS- SOLVED (MG/L AS NA) 19 -- -- ie -- ie RESIDUE TOTAL AT 105 DEC. C, SUS- PENDED (MG/L) 23 226 81 53 16 9 TEMPER- ATURE WATER (DEG C) 27.0 26.0 27.0 27.0 25.0 25.0 SODIUM AD- SORP- TION RATIO 0.6 __ __ 0.6 — 0.6 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 <0.20 0.30 0.20 <0.20 0.26 TUR- BID- ITY (NTU) 11 130 41 24 7.3 5.2 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 0.90 -- __ 0.90 -- 0.80 PHOS- PHORUS TOTAL (MG/L AS P) 0.020 0.070 0.060 0.050 0.080 0.060 OXYGEN, DIS- SOLVED (MG/L) 5.9 3.7 6.5 4.4 7.0 4.6 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CAC03 160 150 190 150 160 180 ARSENIC TOTAL (UG/L AS AS) 1 -- -- <1 — -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 74 45 80 55 84 56 SULPIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 __ — — BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) 100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 15 30 <10 <10 <10 SULFATE DIS- SOLVED (MG/L AS SO4) 46 — -- 30 -- 44 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 20 -- -- 40 -- — COLI- PORM, FECAL, 0.45 UM-MP (COLS./ 100 ML) K150 K120 240 2000 650 510 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 8.0 -- -- 10 -- 8.7 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 __ -- <1 -- __ STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K140 K70 K160 920 120 440 PLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.20 — -- 0.20 -- 0.20 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 1 -- -- <1 -- -- K = non-ideal count 366 RIO BUCANA BASIN 50114000 RIO CERRILLOS NEAR PONCE, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS FE) AS PB) AS MN) AS HG) AS SB) AS AG) AS ZN) AS CN) (UG/L) OCT 1994 27. .. DEC 23. .. FEB 1995 22. . . APR 27. .. JDN 16. .. AUG 22. . . 630 1300 90 <0.10 120 <0.10 10 <0.010 <0.010 (MG/L) <0.02 7 0.02 RIO BUCANA BASIN 50114390 RIO BUCANA AT HWY 14 BRIDGE NEAR PONCE, PR LOCATION.--Lat 18°02'29", long 66°34'58", Hydrologic Unit 21010004, on left bank, 200 ft (61 m) upstream from bridge on Highway 14 and 4.0 mi (6.4 km) downstream from Lago Cerrillos' Dam, 2.8 mi (4.5 km) northeast of Degetau Plaza in Ponce. 367 DRAINAGE AREA.--24.9 mi' (64.5 km 9 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1985 to September 1986 (maximum only), published as "Rio BUGanA Floodway Channel at Highway 14 bridge", October 1986 to July 1987 (maximum only), August 1987 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 116.40 ft (35.500 m) above mean sea level. Prior to Oct. 1, 1986, crest-stage gage located at Highway 14 bridge, at elevation of mean sea level. REMARKS.--Records poor. Flow regulated by Lago Cerrillos Dam 0.4 mi upstream. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT NOV 1 5.8 8.5 2 5.0 9.1 3 4.8 11 4 4.7 159 5 5.0 62 6 4.9 11 7 8.6 10 8 5.2 9.5 9 4.9 10 10 4.9 10 11 5.2 8.3 12 4.8 7.7 13 4.9 7.7 14 4.9 7.3 15 4.7 7.4 16 4.6 6.6 17 11 6.6 18 10 6.2 19 11 5.5 20 12 4.7 21 17 5.1 22 27 5.0 23 37 4.9 24 20 4.2 25 77 5.5 26 16 5.2 27 12 4.9 28 11 5.2 29 10 5.7 30 8.7 5.9 31 8.6 —— TOTAL 371.2 419.7 MEAN 12.0 14 . 0 MAX 77 159 MIN 4.6 4.2 AC-FT 736 832 CFSM .48 .56 IN. .55 .63 STATISTICS OF MONTHLY MEAN MEAN 142 65.5 MAX 527 222 (WY) 1991 1988 MIN 12.0 5.09 (WY) 1995 1994 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAR FLOW INSTANTANEOUS PEAR STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS DEC 6.1 6.6 6.7 6.5 6.4 6.1 6.0 5.9 5.8 5.6 5.1 5.2 .8 .8 .7 .7 .7 .9 5.2 5.2 5.0 5.0 5.6 5.2 5.6 6.5 6.4 7.6 6.8 5.8 5.4 175.9 5.67 7.6 4.7 349 .23 .26 DATA 17.6 49.1 1988 5.49 1994 FOR JAN 5.5 6.3 5.9 5.4 5.4 5.4 5.1 5.2 5.2 5.0 5.0 4.8 4.7 5.5 4.4 4.8 6.0 6.5 6.2 5.9 4.7 4.9 6.5 6.5 7.9 6.9 6.4 6.4 6.0 6.2 6.5 177.1 5.71 7.9 4.4 351 .23 .26 FOR WATER 51.8 337 1992 4.51 1994 FEB 6.1 6.2 5.9 5.5 5.6 5.5 5.6 6.2 6.1 6.0 5.5 6.2 6.2 6.2 5.8 5.3 5.3 4.9 4.6 4.7 18 7.0 6.7 7.7 38 238 102 9.2 ___ 540.0 19.3 238 4.6 1070 .77 .81 YEARS 1987 10.7 19.3 1995 4.10 1994 MAR 9.1 7.2 6.5 6.8 6.1 5.2 5.1 4.0 4.0 5.1 5.6 5.0 4.6 5.0 5.2 4.9 4.7 4.8 5.1 5.5 5.7 5.7 5.2 5.6 4.9 5.5 5.1 5.3 4.7 5.1 4.9 167.2 5.39 9.1 4.0 332 .22 .25 - 1995 13.2 48.0 1989 4.49 1994 1994 CALENDAR YEAR 2360. 6. 159 3. 3. 4680 3. 7. 4. 3. 1 47 Nov 4 1 Feb 8 3 Feb 6 26 53 5 5 9 APR 5.1 .7 .7 .6 .7 .7 .9 .8 5.0 4.7 12 16 8.6 8.6 8.0 7.8 32 17 9.9 8.4 7.8 7.5 7.3 6.8 6.6 5.9 5.6 5.9 6.0 6.2 ___ 241.8 8.06 32 4.6 480 .32 .36 , BY WATER 15.7 42.5 1992 4.74 1994 MAY 6.4 5.7 5.0 5.9 6.8 11 35 26 32 11 9.4 8.9 8.1 8.0 7.8 11 6.8 6.3 6.6 15 9.3 7.7 7.3 6.9 7.1 8.8 8.0 21 15 9.6 8.9 342.3 11.0 35 5.0 679 .44 .51 YEAR (WY) 28.7 94.9 1992 4.29 1994 JUN 9.0 9.4 9.5 7.9 7.4 7.5 7.0 6.9 6.7 7.1 7.4 6.6 6.2 6.0 5.9 6.2 6.2 5.6 5.4 4.8 5.0 4.7 4.3 4.5 4.1 4.9 5.7 5.8 5.4 5.1 —— 188.2 6.27 9.5 4.1 373 .25 .28 28.3 80.5 1989 4.90 1994 FOR 1995 WATER YEAR 3792.5 10.4 238 3.2 3.8 1700 11.14 7520 .42 5.67 12 6.2 4.7 Feb 26 Aug 15 Aug 9 Feb 26 Feb 26 JUL 5.2 5.0 .8 .9 .8 .6 .5 .3 .3 .2 .2 .6 .2 .4 6.3 11 7.0 6.4 6.1 5.5 5.6 6.4 6.1 4.9 4.5 4.0 3.9 11 6.7 6.2 6.1 171.7 5.54 11 3.9 341 .22 .26 20.5 51.4 1991 4.37 1994 WATER 43. 78. 7. 4340 2. 2. 14700 13. 31560 1. 23. 80 11 4. AUG 5.7 6.3 6.6 5.7 5.2 6.5 5.7 4.9 4.6 4.3 4.0 3.8 3.6 3.4 3.2 12 11 49 179 134 26 17 53 21 15 13 12 11 10 9.1 11 656.6 21.2 179 3.2 1300 .85 .98 48.3 169 1988 4.06 1994 YEARS 1987 6 0 43 Jan 5 Sep 8 Sep Oct 48 Oct 75 77 6 SEP 11 9.2 8.3 7.5 7.3 8.0 11 11 7.9 6.8 10 7.8 6.9 6.3 7.3 40 37 13 13 14 8.5 7.5 13 8.9 9.9 12 10 9.1 11 7.6 340.8 11.4 40 6.3 676 .46 .51 68.8 265 1989 7.12 1993 - 1995 1991 1994 6 1992 28 1992 23 1992 7 1985 7 1985 368 RIO PORTUGUES BASIN 50115000 RIO PORTOGUES NEAR PONCE, PR LOCATION.--Lat 180 04'45", long 66°38'01", Hydrologic Unit 21010004, on right bank 30 ft (9 m) upstream from bridge on Highway 504, 0.2 mi (0.3 km) upstream from small unnamed tributary, 4.4 mi (7.1 km) upstream from Rio Chiquite, and 4.7 mi (7.6 km) north of Plaza Degetau in Ponce. DRAINAGE AREA.--8.82 mi> (22.84 km'). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February to June 1964 (monthly measurements only), July 1964 to current year. GAGE.--Water-stage recorder. Elevation of gage is 470 ft (143 m), from topographic map. Prior to Dec. 4, 1964, non-recording gage at same site and datum. REMARKS.--Records poor. Some low-flow regulation due to unknown activity upstream. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR MAY JON JUL 1 39 7.8 2 9.5 57 3 6.3 23 4 5.1 12 5 5.3 9.4 6 5.4 7.6 7 11 7.1 8 150 6.3 9 67 9.6 10 22 9.1 11 14 7.4 12 11 6.2 13 11 5.8 14 9.2 5.7 15 11 5.4 16 18 4.9 17 45 5.0 18 21 5.0 19 13 5.0 20 14 4.6 21 51 .4 22 241 .4 23 94 .0 24 153 .3 25 134 .9 26 38 5.1 27 18 20 28 12 11 29 9.1 6.2 30 8.0 7.1 31 7.2 —— TOTAL 1253.1 275.3 MEAN 40.4 9.18 MAX 241 57 MIN 5.1 4.0 AC-FT 2490 546 CFSM 4.58 1.04 IN. 5.29 1.16 STATISTICS OF MONTHLY MEAN MEAN 46.4 31.9 MAX 120 80.1 (WY) 1986 1988 MIN 11.9 5.82 (WY) 1992 1994 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 7.5 8.6 6.8 8.6 5.9 5.2 5.0 4.7 4.2 3.9 3.9 4.1 3.6 3.7 3.5 3.8 3.3 3.3 3.1 3.6 4.1 3.3 3.9 3.3 4.2 3.0 3.5 5.2 2.9 2.6 2.6 134.9 4.35 8.6 2.6 268 .49 .57 DATA 12.1 27.3 1988 2.71 1992 FOR 2.6 2.8 2.7 2.7 2.6 2.6 2.4 2.4 2.6 2.4 2.4 2.4 2.7 2.7 43 13 eB.l e9.2 e4.0 e3.3 e2.9 e3.2 e3.2 e2.8 e3.1 e3.7 e3.4 e2.9 e2.7 e2.6 e2.6 149.7 4.83 43 2.4 297 .55 .63 e2.6 e2.4 e2.3 e2.3 e2.5 e2.6 e2.6 e3.4 e2.9 e3.9 e2.6 e2.5 e2.4 e2.5 e2.4 e2.4 e2.5 e2.4 e2.4 e2.7 e21 eB.B e35 e!3 e45 e88 e33 e26 ___ —— 322.1 11.5 88 2.3 639 1.30 1.36 FOR WATER YEARS 1964 8.72 45.5 1992 3.65 1989 6.25 13.3 1976 2.62 1989 e21 e!7 e!6 el4 e8.4 e6.8 e6.0 e5.6 e6.2 e20 e27 e!2 e9.2 e8.0 e6.8 e6.4 e6.0 e5.8 e5.8 e5.4 e5.4 e5.2 5.8 5.5 5.0 5.1 4.9 4.7 4.8 4.8 5.2 269.8 8.70 27 4.7 535 .99 1.14 - 1995 5.73 13.4 1976 2.08 1977 1994 CALENDAR YEAR 3086.84 8.46 241 .61 1.0 6120 .96 13.02 12 3.2 1.4 Oct 22 Jul 29 Jul 9 5.0 4.9 5.0 4.6 4.7 5.3 5.5 6.0 5.3 5.4 14 15 5.7 5.0 5.6 6.3 56 19 6.1 4.8 4.3 3.9 3.5 3.5 3.5 3.1 3.1 3.1 3.1 3.0 --- 223.3 7.44 56 3.0 443 .84 .94 , BY WATER 7.47 27.1 1983 2.45 1974 2.7 2.7 2.4 2.5 48 34 105 208 109 41 14 9.0 6.8 5.6 59 31 11 7.2 5.8 6.7 6.9 4.7 4.1 3.5 3.7 4.0 47 23 7.0 86 41 942.3 30.4 208 2.4 1870 3.45 3.97 YEAR (WY) 19.9 72.9 1985 1.65 1973 49 38 28 20 40 29 14 10 100 63 17 11 8.1 6.7 6.1 6.3 5.1 5.4 6.2 5.8 5.8 5.2 4.8 6.1 11 5.2 6.2 6.6 4.9 4.5 --- 529.0 17.6 100 4.5 1050 2.00 2.23 14.9 48.3 1979 2.33 1974 FOR 1995 WATER YEAR 6854.0 18.8 402 2.3 2.4 1020 6.35 13590 2.13 28.91 45 6.3 2.7 Sep 16 Feb 3 Feb 13 Sep 16 Sep 16 5.2 6.2 5.4 6.8 7.0 6.1 5.4 5.9 5.8 5.6 5.7 6.2 12 6.3 26 61 15 8.9 7.9 6.3 8.3 11 e9.0 e8.2 e6.6 e6.6 e24 e!3 e66 e33 elB 418.4 13.5 66 5.2 830 1.53 1.76 14.2 54.2 1979 1.49 1994 WATER 18 38 7 2440 1 21000 20 13500 2 28 40 8 3 8.1 6.4 8.4 5.8 28 14 7.3 7.5 7.6 9.7 6.7 5.8 6.2 5.2 6.8 45 27 110 286 141 71 28 13 8.9 7.4 5.9 5.2 10 9.0 17 7.5 925.4 29.9 286 5.2 1840 3.38 3.90 20.3 87.5 1979 4.20 1972 YEARS 1964 .6 .0 .04 Sep .61 Jul .0 Jul Oct .20 Oct .11 .71 .0 .0 5.1 4.7 5.1 5.0 7.0 36 83 61 29 16 28 22 15 e9.8 e39 e402 ellO e78 e88 e70 e45 e40 57 46 29 18 20 16 14 12 1410.7 47.0 402 4.7 2800 5.33 5.95 34.5 132 1975 7.22 1991 - 1995 1979 1994 16 1975 29 1994 9 1994 7 1985 7 1985 e Estimated PERIOD OF RIO PORTUGDES BASIN 50115000 RIO PORTUGUES NEAR PONCE, PR—Continued WATER-QUALITY RECORDS RECORD.—Water years 1964 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 369 DATE OCT 1994 27. .. DEC 23. .. FEB 1995 22. . . APR 27. . . JXJN 19. . . AU6 22. .. DATE OCT 1994 27. .. DEC 23. .. FEB 1995 22. .. APR 27... JON 19. .. AU6 22. .. DATE OCT 1994 27. .. DEC 23. .. FEB 1995 22. . . APR 27. .. JON 19. .. AU6 22. .. TIME 0905 0845 1125 1240 0915 1045 HARD- NESS TOTAL (MG/L AS CAC03) 120 -- — 140 __ 110 SILICA, DIS- SOLVED (MG/L AS SIO2) 21 -- -- 20 -- 21 DIS- CHARGE, INST. CUBIC FEET PER SECOND 19 4.7 7.4 3.0 7.0 23 CALCIUM DIS- SOLVED (MG/L AS CA) 39 __ -- 43 -- 36 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 169 -- -- 199 __ 155 SPE- CIFIC CON- DUCT- ANCE (US/CM) 291 320 260 304 331 250 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 6.3 — __ 7.0 — 5.7 SOLIDS, DIS- SOLVED (TONS PER DAY) 9.36 — — 1.54 -- 9.52 FH WATER WHOLE FIELD (STAND- ARD UNITS) 9.0 7.9 7.9 9.0 7.9 7.9 SODIUM, DIS- SOLVED (MG/L AS NA) 9.3 __ -- 11 -- 9.7 RESIDUE TOTAL AT 105 DEC. C, SUS- PENDED (MG/L) 7 <1 4 3 3 30 TEMPER- ATURE WATER (DEC C) 23.0 22.5 23.0 26.0 22.5 24.5 SODIUM AD- SORP- TION RATIO 0.4 — — 0.4 — 0.4 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 <0.20 <0.20 <0.20 <0.20 0.29 TUR- BID- ITY (NTU) 2.7 0.60 3.6 0.60 0.40 19 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 1.3 __ -- 1.3 -- 1.2 PHOS- PHORUS TOTAL (MG/L AS P) 0.030 0.020 0.040 0.030 0.050 0.020 OXYGEN, DIS- SOLVED (MG/L) 6.0 5.2 9.3 4.2 6.4 2.6 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 120 170 160 150 170 110 ARSENIC TOTAL (UG/L AS AS) <1 -_ _- <1 -- — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 69 60 95 51 74 31 SULFIDE TOTAL (MG/L AS S) <0.5 __ __ <0.5 -_ — — BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -_ -_ <100 -- __ OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 <10 14 <10 <10 <10 SULFATE DIS- SOLVED (MG/L AS SO4) 9.7 — — 7.9 -- 9.4 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 20 -- — 20 — — COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 260 310 K170 K45 60 K190 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 9.9 __ _- 9.7 -_ 7.7 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 470 530 240 K140 110 90 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 __ -- <0.10 -- <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 -- — non-ideal count 370 RIO PORTUGUES BASIN 50115000 RIO PORTUGUES NEAR PONCE, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 27. .. DEC 23. .. FEB 1995 22... APR 27. .. JUN 19. .. AUG 22. .. COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 __ -- <10 __ — IRON, TOTAL RECOV- ERABLE (UG/L AS FE) 130 __ -- 70 __ __ LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) <1 __ -- 1 __ __ MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 10 __ -- • 10 __ __ MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 __ -- <0.10 __ __ SELE- NIUM, TOTAL (UG/L AS SE) <1 __ -- <1 __ __ SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <1 __ -- <1 __ __ ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) <10 __ -- <10 __ __ CYANIDE TOTAL PHENOLS (MG/L TOTAL AS CN) (UG/L) <0.010 <1 __ __ <0.010 <1 __ __ MBTHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) <0.02 -- -- <0.02 -- -- RIO PORTUGUES BASIN 371 50116200 RIO PORTUGUES AT PONCE, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°00'20", long 66036'28", 1,300 ft (400 m) south of Las Americas Avenue Bridge, 1.2 ml (1.9 km) south of CSC 50115900, 0.8 mi (1.3 km) west of Highways 1 and 2 junction, and 0.7 mi (1.1 km) southeast of Ponce. DRAINAGE AREA.--18.9 mi 2 (49.0 km 2 ). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 26. . . DEC 08. . . FEB 1995 17. .. APR 20. . . JUN 14. . . AUG 03. . . DATE OCT 1994 26. .. DEC 08. . . FEB 1995 17. . . APR 20. . . JUN 14. .. AUG 03. . . TIME 1030 1000 0805 0845 0920 1025 HARD- NESS TOTAL (MG/L AS CAC03) 140 -- — 190 — 46 SILICA, DATE OCT 1994 26. .. DEC oe. .. FEB 1995 17... APR 20. .. JUN 14. .. AUG 03. .. K = non-ideal DIS- SOLVED (MG/L AS SIO2) 21 -- -- 15 -- 13 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 40 1.1 1.3 5.8 9.8 4.9 CALCIUM DIS- SOLVED (MG/L AS CA) 42 -- -- 58 -- 11 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 200 -- -- 335 __ 169 SPE- CIFIC CON- DUCT- ANCE (US/CM) 350 619 530 520 390 485 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 7.9 -- -- 11 -- 4.4 SOLIDS, DIS- SOLVED (TONS PER DAY) 21.8 -- -- 5.22 __ 2.22 PH WATER WHOLE FIELD (STAND- ARD UNITS) 8.1 7.6 8.1 7.8 8.0 7.6 SODIUM, DIS- SOLVED (MG/L AS NA) 17 -- -- 39 -- 11 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 32 14 2 9 18 172 TEMPER- ATURE WATER (DBG C) 26.5 23.0 23.0 23.0 25.0 26.0 SODIUM AD- SORP- TION RATIO 0.6 — — 1 — 0.7 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.30 0.50 0.50 0.30 0.24 0.39 TUR- BID- ITY (NTU) 16 7.4 2.5 1.4 3.6 140 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.0 -- -- 1.3 -- 5.6 PHOS- PHORUS TOTAL (MG/L AS P) 0.060 0.080 0.040 <0.010 0.020 0.030 OXYGEN, DIS- SOLVED (MG/L) 6.7 3.8 3.0 3.0 7.8 6.0 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 120 210 210 210 150 170 ARSENIC TOTAL (UG/L AS AS) <1 — -- <1 __ -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 82 43 34 34 94 73 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 -- -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 — -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 11 15 <10 <10 54 SULFATE DIS- SOLVED (MG/L AS SO4) 22 — -- 52 -- 8.9 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 50 -- -- 130 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) K960 390 31000 4300 2400 2300 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 16 -- -- 33 -- 13 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 . — STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K1900 470 K2000 K1700 260 930 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 -- -- 0.20 — <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 1 -- -- <1 -- -- 372 RIO PORTUGUES BASIN 50116200 RIO PORTUGOES AT PONCE, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 26. .. DEC 08. .. FEB 1995 17. .. APR 20. .. JUN 14. .. AUG 03... COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) 10 -- -- 10 __ — IRON, TOTAL RECOV- ERABLE (UG/L AS FE) 990 -- -- 260 __ -- LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) 2 -- __ <1 __ __ MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 60 __ __ 30 __ __ MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 __ — <0.10 __ __ SELE- NIUM, TOTAL (UG/L AS SB) <j. __ __ <j. __ __ SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <! __ __ <j. — — ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) 20 __ __ <10 __ __ CYANIDE TOTAL PHENOLS (MG/L TOTAL AS CN) (UG/L) <0.010 <1 __ __ <0.010 2 __ __ MBTHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) <0.02 -- — 0.02 __ __ PESTICIDE ANALYSES CHLOR- DANE, P,P'- P,P'- ENDO- TECH- ODD DOT DI- DI- SULFAN, PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I DATE TIME 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) JUN 1995 14... 0920 <0 BNDRIN WATER ONFLTRD DATE REC (UG/L) JUN 1995 14... <0.010 PARA- THION, DATE TOTAL (UG/L) JUN 1995 14... <0.010 .100 <0. ETHION, TOTAL (UG/L) <0.010 PCNS UNFILT RECOVER (UG/L) <0.100 ,010 <0 HEPTA- CHLOR, TOTAL (UG/L) <0.010 PER- THANE TOTAL (UG/L) <0.100 .100 <0 HEPTA- CHLOR EPOXIDE TOTAL (UG/L) <0.010 TOX- APHENE, TOTAL (UG/L) <1.00 .010 <0, LINDANE TOTAL (UG/L) <0.010 TOTAL TRI- THION (UG/L) <0.010 .010 <0, MALA- THION, TOTAL (UG/L) <0.010 2,4-D, TOTAL (UG/L) <0.010 .010 <0 METH- OXY- CHLOR, TOTAL (UG/L) <0.010 2,4,5-T TOTAL (UG/L) <0.010 .010 <0. METHYL PARA- THION, TOTAL (UG/L) <0.010 2, 4 -DP TOTAL (UG/L) <0.010 .010 <0.010 MIREX, TOTAL (UG/L) <0.010 SILVEX, TOTAL (UG/L) <0.010 RIO GDAYANILLA BASIN 50124200 RIO GUAYANILLA NEAR GUAYANILLA, PR LOCATION.--Lat 18°02'40", long 66°47'53" r Hydrologic Unit 21010004, on left bank, 0.7 mi (1.1 km) north of junction of Highways 2 and 132, 0.6 mi (1.0 km) downstream from Quebrada Conaejo, 1.8 mi (2.9 km) north-northweat from Plaza de Guayanilla. DRAINAGE AREA.--18.9 mi 9 (49.0 km j ). HATER-DISCHARGE RECORDS PERIOD OP RECORD.--March 1981 to current year. GAGE.--Hater-atage recorder. Elevation of gage ia 80 ft (24 m), from topographic map. REMARKS.--Recorda fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at atation. DISCHARGE, CUBIC PEET PER SECOND, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 373 OCT NOV DEC JUN JUL AUG 1 118 17 2 30 80 3 15 126 4 e9.0 94 5 e5.8 39 6 e4.4 27 7 e6.4 23 8 e7.0 20 9 e39 20 10 e23 21 11 ell 15 12 elO 12 13 elO 12 14 e7.8 10 15 e6.2 9.9 16 e5.6 9.9 17 e4.8 9.8 18 e7.0 9.0 19 ell 9.4 20 e8.6 8.5 21 e7.0 9.6 22 e8.6 9.0 23 e!4 6.9 24 e!9 6.8 25 e25 6.3 26 e47 6.3 27 36 123 28 28 60 29 e20 25 30 20 19 31 29 TOTAL 593.2 844.4 MEAN 19.1 28.1 MAX 118 126 MIN 4.4 6.3 AC-PT 1180 1670 CPSM 1.01 1.49 IN. 1.17 1.66 16 19 15 18 17 15 13 11 12 9.4 8.0 7.8 6.8 6.3 6.3 6.1 5.9 5.9 5.5 5.4 12 8.0 16 8.7 6.1 5.2 4.4 11 6.0 4.6 4.0 295.4 9.53 19 4.0 586 .50 .58 STATISTICS OP MONTHLY MEAN DATA MEAN 61.9 49.5 MAX 167 110 (WY> 1986 1988 MIN 16.0 17.0 (WY) 1983 1994 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK PLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW PLOW ANNUAL RUNOPP (AC-FT) ANNUAL RUNOPP (CPSM) ANNUAL RUNOPP (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 18.6 41.9 1988 6.72 1994 POR 4.2 4.3 4.0 4.0 4.0 3.9 3.8 4.0 8.4 7.8 5.5 4.9 4.8 4.4 4.3 6.8 5.3 4.9 4.4 4.3 4.3 4.0 4.5 4.1 4.2 4.4 4.1 4.0 3.7 3.6 3.6 142.5 4.60 8.4 3.6 283 .24 .28 3.7 3.4 3.3 3.1 3.1 3.1 3.4 5.7 5.2 5.5 6.1 4.8 4.7 4.8 4.6 4.8 4.3 5.9 e5.5 e4.6 eS.l e5.9 ell el3 ell «9.8 el3 e28 ___ 186.4 6.66 28 3.1 370 .35 .37 FOR HATER YEARS 1981 10.3 27.5 1992 4.21 1994 7.15 11.4 1985 3.10 1990 e43 e9.9 e!9 e20 e!2 e!2 e9.0 e7.9 eS.l e4.7 e6.7 e8.9 e9.0 e5.9 e4.9 e4.7 e4.7 e4.9 e4.9 e5.4 e4.9 e4.4 e3.9 e3.9 e3.4 e3.2 2.8 2.1 2.0 2.2 2.1 237.5 7.66 43 2.0 471 .41 .47 - 1995 6.06 13.2 1989 2.85 1981 1994 CALENDAR YEAR 3319.97 9.10 156 .77 1.1 6590 .48 6.53 19 3.7 1.6 Sep 24 Jul 30 Sep 4 2.3 2.4 2.5 2.4 2.2 1.9 1.6 1.5 2.2 1.9 2.4 3.7 2.3 2.0 1.6 1.8 6.3 7.8 5.1 4.3 4.0 3.5 3.4 2.5 2.2 2.1 1.9 1.7 1.7 1.7 82.9 2.76 7.8 1.5 164 .15 .16 1.9 1.8 1.4 1.5 11 73 110 113 52 27 9.4 4.5 2.6 6.8 8.2 11 4.0 2.6 2.1 3.0 6.1 4.0 2.2 2.1 2.4 2.1 1.9 21 7.8 8.2 19 523.6 16.9 113 1.4 1040 .89 1.03 13 9.0 6.0 6.3 4.6 4.8 3.9 3.5 6.3 46 16 10 7.8 7.2 6.7 10 7.4 5.9 4.3 3.5 3.4 2.9 2.2 2.1 2.1 3.0 20 33 11 6.5 —— 268.4 8.95 46 2.1 532 .47 .53 4.7 3.6 2.5 3.4 3.0 2.7 3.0 2.1 1.8 1.9 2.6 3.9 2.3 4.3 3.5 4.1 8.0 18 18 15 28 37 35 18 16 14 14 69 e30 e!5 e8.6 393.0 12.7 69 1.8 780 .67 .77 e7.6 e9.8 e8.7 e8.2 e8.6 e9.0 e8.2 e7.0 e6.4 e7.0 e6.4 e5.8 e6.4 e6.6 e9.2 e!6 e7.6 e37 e41 e!4 elO e9.2 e8.2 e7.4 e6.6 e5.8 e5.2 e!2 e!4 e9.8 e8.6 327.3 10.6 41 5.2 649 .56 .64 e8.4 e9.8 ell e!2 e!9 e38 e42 e24 e!8 e22 e25 e!8 e!5 e!4 e31 e!70 elOO e62 e46 e38 e34 e30 e31 e28 e25 e24 e25 e22 e20 e!9 --- 981.2 32.7 170 8.4 1950 1.73 1.93 , BY WATER YEAR (WY) 10.4 26.6 1983 2.76 1995 POR 1995 4875. 13. 170 1. 1. 1320 10. 9670 . 9. 28 6. 2. 28.3 80.4 1985 2.33 1994 WATER YEAR 8 4 Sep 16 4 May 3 7 Apr 28 Nov 27 38 Nov 27 77 May 27 71 60 8 3 14.7 41.0 1987 3.28 1991 11.8 25.9 1986 2.45 1994 WATER 22. 33. 8. 1500 . 1. 14700 20. . 16320 1. 16. 49 9. 3. 17.3 48.5 1988 6.24 1994 YEARS 1981 5 1 94 Get 77 Jul 1 Sep Sep 40 Sep 77 Jul 19 19 6 4 38.8 102 1981 7.46 1983 - 1995 1986 1994 7 1985 30 1994 4 1994 12 1982 12 1982 30 1994 e Estimated 3 74 RIO GUAYANILLA BASIN 50124700 RIO GUAYANILLA AT CENTRAL RUFINA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°00'40", long 66«>46'49", at dirt road bridge, 0.7 mi (1.1 km) from mouth, 0.9 mi (1.4 km) east of Central Rufina and 0.9 mi (1.4 km) southeast of Quayanilla. DRAINAGE AREA.--22.8 mi 1 (59.1 km'). PERIOD OF RECORD.--Water years 1960-65, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 19. . . DEC 21. .. FEB 1995 15. .. APR 28. . . JUN 23. .. SEP 15. .. DATE OCT 1994 19. .. DEC 21. .. FEB 1995 15. .. APR 28. .. JUN 23. .. SEP 15. .. DATE OCT 1994 19. . . DEC 21. .. FEB 1995 15... APR 28. .. JUN 23. .. SEP 15. . . TIME 1030 0900 1020 0830 1045 0945 HARD- NESS TOTAL (MG/L AS CAC03) 180 -- — 260 -- 190 SILICA, DIS- SOLVED (MG/L AS SI 02) 18 -- -- 26 — 20 DIS- CHARGE, INST. CUBIC FEET PER SECOND 19 6.4 0.69 0.42 0.81 9.3 CALCIUM DIS- SOLVED (MG/L AS CA) 52 -- -- 72 -- 51 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 246 -- -- 615 -- 285 SPE- CIFIC CON- DUCT- ANCE (US /CM) 427 510 771 768 855 478 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 13 __ -- 20 — 15 SOLIDS, DIS- SOLVED (TONS PER DAY) 12.6 — — 0.70 -- 7.18 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.8 7.3 7.2 7.2 7.3 7.3 SODIUM, DIS- SOLVED (MG/L AS NA) 15 __ -- 73 __ 18 RESIDUE TOTAL AT 105 DEC. C, SUS- PENDED (MG/L) 13 8 2 3 3 40 TEMPER- ATURE WATER (DEC C) 26.5 24.0 28.0 27.0 30.0 28.0 SODIUM AD- SORP- TION RATIO 0.5 — -- 2 __ 0.6 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.30 1.3 2.0 4.3 2.1 0.72 TUR- BID- ITY (NTU) 3.8 1.3 1.0 1.2 2.6 25 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.0 __ -- 9.1 _- 2.3 PHOS- PHORUS TOTAL (MG/L AS P) 0.170 0.370 2.90 2.30 1.80 0.870 OXYGEN, DIS- SOLVED (MG/L) 5.8 5.8 2.6 0.8 4.3 2.7 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CAC03 140 200 210 290 160 190 ARSENIC TOTAL (UG/L AS AS) 2 — -- 1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 71 68 32 10 56 34 SULFIDE TOTAL (MG/L AS S) 1.8 __ -- 4.8 -- -- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 25 16 24 18 19 12 SULFATE DIS- SOLVED (MG/L AS S04) 44 __ — 91 -- 45 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 40 -- -- 180 — -- COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 4700 23000 240 230 4400 K1200 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 18 __ -- 150 -_ 20 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 700 K1500 K130 970 3400 880 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 — -- 0.10 -- <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 -- -- K • non-ideal count RIO GDAYANILIA BASIN 50124700 RIO GUAYANILLA AT CENTRAL RUPINA, PR--Continue HATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 375 DATE OCT 1994 19... DEC 21... FEE 1995 15. .. APR 29. . . JUN 23. .. SEP 15. .. COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 -- -- <10 -- — IRON, TOTAL RECOV- ERABLE (UO/L AS FE) 350 _- -- 70 __ -- LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) <1 — — <1 __ — MANGA- NESE, TOTAL RECOV- ERABLE (UO/L AS UN) 30 __ __ 140 __ -_ MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 __ — <0.10 __ — SELE- NIUM, TOTAL (UG/L AS SB) <1 __ __ <1 __ — SILVER, TOTAL RECOV- ERABLE (UO/L AS AG) <1 __ __ <1 __ — ZINC, TOTAL RECOV- ERABLE (UO/L AS ZN) <10 __ -- 10 __ __ CYANIDE TOTAL (MG/L AS CN) <0.010 — — <0.010 __ — PHENOLS TOTAL (UO/L) 2 -_ -- 2 __ __ METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) 0.02 — -- 0.16 __ — PESTICIDE ANALYSES DATE JUN 1995 23. .. DATE JUN 1995 23.. . DATE JUN 1995 23.. . CHLOR- DANB, P,P'- P,P'- ENDO- TECH- ODD DDT DI- DI- SULFAN, PCB, ALDRIN, NICAL UNFILT DDE, UNPILT AZINON, ELDRIN I TIME TOTAL TOTAL TOTAL RECOVER TOTAL RECOVER TOTAL TOTAL TOTAL (UO/L) (UG/L) (UO/L) (UG/L) (UG/L) (UG/L) (UG/L) (UO/L) (UG/L) 1045 <0 ENDRIN HATER UNPLTRD REC (UO/L) <0.010 PARA- THION, TOTAL (UG/L) .100 <0. ETHION, TOTAL (UO/L) <0.010 PCNS UNFILT RECOVER (UG/L) 010 <0 HEPTA- CHLOR, TOTAL (UO/L) <0.010 PER- THANE TOTAL (UG/L) .100 <0. HEPTA- CHLOR EPOXIDE TOTAL (UO/L) <0.010 TOX- APHENE, TOTAL (UG/L) .010 <0. LINDANE TOTAL (UO/L) <0.010 TOTAL TRI- THION (UG/L) .010 <0, MALA- THION, TOTAL (UO/L) <0.010 2,4-D, TOTAL (UG/L) ,010 0 METH- OXY- CHLOR, TOTAL (UG/L) <0.010 2,4,5-T TOTAL (UG/L) .300 <0. METHYL PARA- THION, TOTAL (UG/L) <0.010 2, 4-DP TOTAL (UO/L) 010 <0.010 MIREX, TOTAL (UG/L) <0.010 SILVEX, TOTAL (UO/L) <0.010 <0.100 <0.100 <1.00 <0.010 0.040 <0.010 <0.010 <0.010 376 RIO YAUCO BASIN 50125780 LAGO LUCCHETTI AT DAMSITE NEAR YAUCO, PR LOCATION.--Lat 18°05'37", long 66°51'54", Hydrologie Unit 21010004, at Antonio Lueehetti Dam on Rio Yaueo, 3.9 mi (6.3 km) north of Yaueo. DRAINAGE AREA. --17. 4 mi 1 (45.1 km1 ). ELEVATION RECORDS PERIOD OF RECORD. --December 1989 to current year. Prior to October 1994, published as Lago Lucchetti at Damsite. GAGE. --Water-stage recorder. Datum of gage is mean sea level. REMARKS. --Lago Lucchetti was completed in 1952. The dam is on Rio Yauco and is a unit of the Southwestern Puerto Rico Project. It provides 16,500 acre-feet (20.3 ha3 ) of usable storage for power generation and irrigation. The dam is a concrete gravity structure with a total length of 591 ft (180 m) , a maximum height of 178 ft (54 m) , and a maximum width at the base of 150 ft (46 m) . An ungated, overflow type spillway with a clear length of 171 ft (52 m) and a crest elevation of 570 ft (174 m) , occupies the central portion of the dam. The spillway was designed for a maximum capacity of 62,800 ft'/s (1,778 m'/s) at a design head of 20 ft (6 m) . 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, 572.19 ft (174.40 m) , May 27, 1993; minimum elevation, 512.09 ft (156.08 m) , Sept. 9, 1994. EXTREMES OBSERVED FOR CURRENT YEAR .- -Maximum elevation, 569.72 ft (173.65 m) , Nov. 4; minimum elevation, 512.09 ft (156.08 m) , Sept. 9. Capacity Table (based on data from Puerto Rico Water Resources Authority) Elevation, in feet 512 520 525 527 530 532 Contents, in acre-feet 1,505 2,385 2,965 3,255 3,695 3,975 Elevation, in feet 540 550 561 563 571 573 Contents, in acre-feet 5,165 7,020 9, 600 10,125 12,125 12,645 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES DAY OCT DEC JAN MAR APR JDL SEP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX MIN A A A A A A A A A A A A 544.16 544.89 545.01 545.04 545.54 546.20 546.44 547.67 548.82 549.38 550.99 551.60 551.89 552.03 552.19 552.30 552.36 552.50 552.83 ___ ___ 553.21 553.82 554.50 554.68 554.76 554.54 554.52 554.61 555.54 555.85 556.08 556.11 557.56 557.98 558.65 558.80 558.94 559.03 559.75 560.24 560.42 560.67 560.63 560.68 560.73 560.75 561.37 561.55 561.57 561.58 --- 561.58 553.21 561.81 561.91 562.00 562.05 562.09 562.09 562.10 562.12 562.11 562.10 562.07 562.20 562.45 562.60 562.57 562.54 562.53 562.50 562.49 562.66 562.69 562.69 562.69 562.60 562.41 562.19 562.12 562.12 562.10 562.09 562.08 562.69 561.81 562.06 562.03 562.14 562.11 562.09 562.06 562.02 561.99 562.23 562.90 563.76 564.36 564.63 565.85 566.30 566.82 567.21 567.19 566.75 567.12 567.07 567.04 566.98 566.94 566.92 566.89 566.85 566.93 567.05 567.00 567.56 567.56 561.99 567.79 567.80 567.81 567.81 567.81 567.81 567.81 567.79 567.76 567.71 567.64 567.59 567.55 567.49 567.44 566.86 566.83 566.78 566.79 566.79 566.87 566.98 566.98 566.68 566.78 567.22 567.50 567.66 —— 567.81 566.68 567.76 567.76 567.80 567.79 567.79 567.79 567.79 567.78 567.77 567.76 567.76 567.78 567.78 567.77 567.78 567.79 567.78 567.78 567.78 567.89 567.86 567.86 567.86 567.85 567.85 567.85 568.18 570.14 570.22 570.03 570.08 570.22 567.76 569.97 569.91 569.85 569.79 569.71 569.50 569.44 569.50 569.42 569.32 569.29 569.23 569.16 569.12 569.07 569.04 569.29 A A A A A A 568.79 569.16 569.00 568.12 567.89 567.83 567.75 —— ___ ___ 567.68 567.60 566.56 565.79 566.03 566.90 567.70 568.05 568.30 568.39 568.71 568.72 568.75 568.73 568.58 568.24 569.39 570.16 570.35 570.24 570.57 570.17 570.05 569.96 570.13 570.13 569.80 570.08 570.09 570.10 570.02 570.57 565.79 569.27 569.70 569.68 569.89 569.86 569.82 569.96 570.15 569.91 570.00 569.97 569.26 568.57 568.49 567.97 567.43 567.47 567.42 567.25 567.06 566.85 566.73 566.68 566.61 566.57 566.41 566.35 566.04 565.78 565.71 --- 570.15 565.71 565.60 565.60 565.79 565.75 565.64 565.71 566.09 566.47 566.84 567.09 567.08 567.08 566.93 566.80 566.82 566.66 566.58 566.39 566.19 566.24 566.31 566.77 567.60 568.39 568.94 569.07 567.53 566.23 566.86 567.02 566.69 569.07 565.60 565.81 564.78 563.67 562.21 562.21 561.80 561.07 560.46 559.24 558.05 557.16 556.17 554.60 553.51 552.92 551.50 550.46 551.64 552.21 552.10 551.86 551.82 552.46 552.70 552.89 551.43 550.35 549.21 548.14 546.59 546.12 565.81 546.12 544.45 543.73 542.59 541.29 541.40 541.76 542.10 542.55 541.00 541.83 541.55 542.27 540.47 537.66 534.67 539.72 539.37 538.10 537.19 537.69 537.09 537.05 537.31 537.82 536.86 536.35 537.13 536.80 537.47 538.06 544.45 534.67 A No gage-height record RIO LOCO BASIN 50128900 LAGO LOCO AT DAMSITE NEAR YAUCO, PR 377 LOCATION.--Lat 18°02'41", long 66°53'16", Hydrologic Unit 21010004, at Damsits, 2.60 mi (4.18 km) northwest from Yauoo plaza, 0.45 mi (0.72 km) northeast from Esouela Rio Cafias and 0.95 mi (1.53 km) northwest from Bsouela Susua Alta. DRAINAGE AREA.--8.40 mi' (21.8 km'). ELEVATION RECORDS PERIOD OP RECORD.--May 1995 to September 1995. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Loco was completed in 1951. The dam is a concrete gravity structure with a total lenght of 600 ft (183 m) , maximum structural height of 72 ft (21.9 m), the ungated overflow spillway is 150 ft (47.7 m) long with crest at elevation of 230 ft (70.1 m) . It has a normal storage capacity of 1,950 acre-feet (2.40 hm3 ) as for Hay 4, 1979. The Loco Dam is owned by the Puerto Rico Electric Power Authority (P.R.E.P.A) and its part of the Southwestern Puerto Rico Project which was developed for electric power generation and irrigation of the lands in the Lajas Valley, some of the Project waters are used for water supply in the Lajas area. The maximum drawdown of the Dam is from 230 ft (70.1 m) to 220 ft (67.1 m) and the Capacity Table provided by P.R.E.P.A includes only that portion of the storage for the dam. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR CURRENT PERIOD.--Maximum elevation, 231.32 ft (70.5 m), Aug. 23; minimum elevation, 223.85 ft (68.2 m), June 7. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet 220 225 Contents, in acre-feet 0 299 Elevation, in feet 230 232 Contents, in acre-feet 639 787 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX MXN DEC JAN FEB APR MAY 229.69 229.62 229.69 229.72 230.16 230.00 229.28 228.25 JUN 230.37 229.33 228.86 228.39 226.94 224.91 228.68 229.93 230.25 230.10 229.43 230.23 230.25 229.74 229.93 230.15 229.67 229.20 229.92 230.31 230.36 230.04 229.05 228.57 228.10 JUL 230.12 230.00 229.48 227.92 228.35 228.67 227.75 228.12 227.55 227.57 229.25 229.81 230.88 230.46 230.38 230.40 230.53 230.22 230.40 230.28 230.38 230.22 230.12 230.32 230.05 AUG 230.26 230.25 230.31 230.44 230.54 230.32 230.36 229.95 230.26 230.28 230.39 230.40 230.40 230.24 230.22 230.20 230.22 230.48 230.50 230.43 230.42 230.47 230.54 230.52 230.48 SEP A A A A A A 230.21 230.11 230.14 229.82 229.96 229.97 230.05 230.48 A A A A A A A A A A A 227.19 230.05 229.44 228.60 227.20 230.64 230.32 228.85 230.04 229.91 230.15 230.21 230.72 230.35 230.19 230.12 230.27 230.53 230.68 A A A A A 230.89 230.36 230.50 230.40 ___ 230.37 224.91 230.88 227.55 A No gage height-record 378 RIO LOCO BASIN 50129700 RIO LOCO AT GOANICA, PR WATER-QUALITY RECORDS LOCATION.—Lat 17°58'33", Ions 66°54'52", 0.6 mi (1.0 km) northwest of Guanica and 1.2 mi (1.9 km) northeast of Ensenada. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1975 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 19. . . DEC 22. .. FEB 1995 15. .. APR 27. .. JUN 23. . . SEP 15. .. DATE OCT 1994 19. .. DEC 22. . . FEB 1995 15. . . APR 27. .. JUN 23. .. SEP 15... DATE OCT 1994 19. .. DEC 22. .. FEB 1995 15. .. APR 27. .. JTJN 23. .. SEP 15. . . TIME 1145 1020 1125 1435 0930 0745 HARD- NESS TOTAL (MG/L AS CAC03) 130 -- -- 3000 -- 130 SILICA, DIS- SOLVED (MG/L AS SI 02) 22 -- — 11 -- 22 SPE- CIFIC CON- DUCT- ANCE (US/CM) 499 17800 30400 25200 8600 278 CALCIUM DIS- SOLVED (MG/L AS CA) 33 -- -- 220 -- 27 SOLIDS, SUM OF CONSTI - TUENTS, DIS- SOLVED (MG/L) 297 -- -- 15700 -- 179 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.1 7.4 7.6 7.3 7.4 7.2 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 12 -_ — 600 -- 16 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 18 13 24 25 24 25 TEMPER- ATURE WATER (DEG C) 27.5 27.0 29.0 30.0 27.0 26.5 SODIUM, DIS- SOLVED (MG/L AS NA) 52 -- -_ 4700 -- 12 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.80 0.50 0.40 0.40 0.52 0.40 TUR- BID- ITY (NTU) 13 2.6 4.5 8.2 15 17 SODIUM AD- SORP- TION RATIO 2 -- -- 37 -- 0.5 PHOS- PHORUS TOTAL (MG/L AS P) 0.600 0.160 0.100 0.080 0.040 0.050 OXYGEN, DIS- SOLVED (MG/L) 0 1.2 1.0 1.7 2.5 1.5 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 6.2 -- -_ 18 -_ 2.4 ARSENIC TOTAL (UG/L AS AS) 3 _- __ 2 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 0 14 13 22 32 18 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 140 260 180 210 120 130 BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- __ 100 -- — OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 48 340 90 520 14 12 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- 0.6 -- - - BORON, TOTAL RECOV- ERABLE (UG/L AS B) 100 -- -_ 2200 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) K690 4400 2100 3100 K1800 K900 SULFATE DIS- SOLVED (MG/L AS S04) 28 — -- 1100 -- 11 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- __ <10 -_ — STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 2400 3200 4100 4300 2900 K820 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 60 -- -- 8900 -- 11 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 2 -- -_ 2 -- -- FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.20 -- -- 0.60 — <0.10 COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 -- _- 30 — — K = non-ideal count RIO LOCO BASIN 50139700 RIO LOCO AT GUANICA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 379 DATE OCT 1994 19. .. DEC 22. .. FEB 1995 15... APR 27. .. JDN 23. .. SEP 15. .. COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 -- -- 30 -- -- IRON, TOTAL RECOV- ERABLE (UG/L AS FE) 710 __ -- 230 __ -- LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) <1 _- -- <10 -- -- MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 190 __ __ 120 __ _- MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 __ __ <0.20 __ __ SELE- NIUM, TOTAL (UG/L AS SB) <1 __ __ <1 __ __ SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <1 __ __ <1 __ __ ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) <10 __ __ <10 __ __ CYANIDE TOTAL PHENOLS (MG/L TOTAL AS CN) (UG/L) <0.010 5 __ __ <0.010 2 __ __ METHY- LENE BL0E ACTIVE SUB- STANCE (MG/L) 0.04 -- -- 0.18 -- -- PESTICIDE ANALYSES DATE JON 1995 23. .. JON 1995 23. .. DATE JON 1995 23.. . CHLOR- DANB, P,P'- P,P'- ENDO- TBCH- ODD DOT DI- DI- SULFAN, PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I TIME 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) 0930 <0, ENDRIN WATER UNFLTRD REC (UG/L) <0.010 PARA- THION, TOTAL (UG/L) .100 <0. ETHION, TOTAL (UG/L) <0.010 PCNS UNPILT RECOVER (UG/L) ,010 <0 HEPTA- CHLOR, TOTAL (UG/L) <0.010 PER- THANE TOTAL (UG/L) .100 <0, HBPTA- CHLOR EPOXIDE TOTAL (UG/L) <0.010 TOX- APHENE, TOTAL (UG/L) .010 <0, LINDANE TOTAL (UG/L) <0.010 TOTAL TRI- THION (UG/L) .010 <0. MALA- THION, TOTAL (UG/L) <0.010 2,4-D, TOTAL (UG/L) .010 <0. MBTH- OXY- CHLOR, TOTAL (UG/L) <0.010 2,4,5-T TOTAL (no/L) .010 <0, METHYL PARA- THION, TOTAL (UG/L) <0.010 2, 4-DP TOTAL (UG/L) .010 <0.010 MIREX , TOTAL (UG/L) <0.010 SILVEX, TOTAL (UG/L) <0.010 <0.100 <0.100 <1.00 <0.010 0.030 <0.010 <0.010 <0.010 380 THIS PAGE WAS LEFT BLANK INTENTIONALLY 01 23456 KILOMETERS 01234 MILES 'lijAretn EXPLANATION A 138° SURFACE-WATER STATION AND NUMBER T 1297 QUALITY-OF-WATER STATION AND NUMBER ^ 1364 DA| LY SEDIMENT STATION AND NUMBER • 143 WELL AND WELL NUMBER SEA Figure 25.--Rio Guanajibo basin, co 00 382 RI° GUANAJIBO BASIN 50131990 RIO GUANAJIBO AT HWY 119 AT SAN GERMAN, PR LOCATION.—Lat 18°05'06", long 67°02'02", Hydrologic Unit 21010003, on left bank, at bridge on Hwy 119, 0.6 mi (1.0 km) southwest of junction of Highways 119 and 2, 0.2 mi (0.3 km) northeast of junction of Highways 119 and 102, 0.7 mi (1.1 km) east from public Plaza of San German. DRAINAGE AREA.--34.6 mi 1 (89.6 km'). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--April 1991 to current year. GAGE. --Water- stage recorder. Elevation of gage is 148 ft (45 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, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY OCT NOV DEC MAR MAY JDN AUG SEP 1 155 118 2 132 306 3 65 344 4 35 250 5 18 151 6 28 105 7 139 79 8 258 255 9 184 191 10 157 125 11 99 105 12 72 80 13 57 62 14 94 46 15 54 38 16 33 31 17 100 25 18 123 111 19 85 157 20 220 148 21 150 87 22 137 65 23 118 54 24 117 47 25 124 37 26 94 36 27 110 110 28 102 121 29 94 93 30 141 73 31 158 —— TOTAL 3453 3450 MEAN 111 115 MAX 258 344 MIN 18 25 MED 110 99 AC-FT 6850 6840 CFSM 3.22 3.32 IN. 3.71 3.71 STATISTICS OF MONTHLY MEAN MEAN 94.8 68.2 MAX 205 123 (WY) 1993 1993 MIN 20.4 15.8 (WY) 1992 1992 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 67 84 124 109 82 69 58 53 55 43 36 31 28 27 26 24 32 23 21 20 22 20 20 15 14 13 13 11 12 11 11 1174 37.9 124 11 26 2330 1.09 1.26 DATA 27.8 52.2 1993 6.21 1992 FOR 11 10 11 9.9 9.2 10 8.8 9.1 28 20 12 26 15 10 12 27 13 11 11 9.9 9.2 9.5 9.2 9.2 9.2 9.2 9.9 10 10 8.6 7.8 375.7 12.1 28 7.8 10 745 .35 .40 7.5 8.0 8.2 8.6 7.8 9.7 7.7 7.9 6.4 7.5 6.0 e5.6 e5.5 e5.5 e5.4 e7.3 7.8 12 27 25 28 21 13 11 91 303 94 276 —— 1023.4 36.5 303 5.4 8.1 2030 1.06 1.10 FOR WATER YEARS 1991 22.6 37.3 1992 10.5 1994 18.5 36.5 1995 4.32 1992 101 37 38 22 18 16 92 62 25 102 45 22 17 15 33 15 13 12 11 11 11 9.9 9.3 8.9 8.9 8.7 7.9 8.2 7.3 6.8 7.2 801.1 25.8 102 6.8 15 1590 .75 .86 - 1995 12.5 25.8 1995 3.52 1992 1994 CALENDAR YEAR 11839. 32. 344 2. 2. 23480 12. 102 8. 3. 7 4 Nov 3 1 Jul 2 7 Jun 1 94 73 6 2 7.0 6.6 6.7 6.3 6.1 5.5 5.9 8.2 8.3 7.6 26 13 9.1 8.6 6.8 19 12 21 9.0 7.2 6.4 6.2 6.2 5.8 5.8 5.3 5.4 6.2 6.0 5.6 --- 258.8 8.63 26 5.3 6.6 513 .25 .28 , BY WATER 16.4 25.4 1994 8.63 1995 5.4 5.3 6.0 11 65 235 478 236 170 175 45 34 46 118 124 42 30 21 17 143 34 20 17 16 15 16 22 27 22 17 18 2230.7 72.0 478 5.3 27 4420 2.08 2.40 YEAR (WY) 45.0 72.0 1995 5.11 1994 16 16 15 13 11 11 11 10 16 13 11 9.2 9.0 9.5 9.2 8.5 8.3 7.7 7.2 7.4 8.3 7.0 6.3 6.5 6.5 10 97 88 14 9.7 —— 472.3 15.7 97 6.3 9.9 937 .46 .51 16.5 46.3 1993 3.91 1994 FOR 1995 WATER YEAR 21372.0 58.6 913 5.3 5.6 3490 10.81 42390 1.69 22.98 149 18 7.2 Sep 16 Apr 26 Apr 26 Nov 2 Nov 2 7.6 6.9 25 65 12 9.4 9.7 8.4 7.2 9.7 39 49 21 19 15 14 10 8.6 8.3 52 74 293 106 46 26 60 18 36 71 21 18 1165.8 37.6 293 6.9 19 2310 1.09 1.25 19.1 37.6 1995 6.68 1994 WATER 38 58 16 913 1 1 6610 13 27580 1 14 87 15 4 14 13 14 11 11 15 10 9.1 8.7 8.3 8.1 7.8 7.9 8.0 7.4 7.4 8.4 330 623 217 70 256 787 459 226 93 51 34 28 22 18 3383.1 109 787 7.4 14 6710 3.15 3.64 38.6 109 1995 17.2 1994 YEARS 1991 .1 .6 .6 Sep .5 May .8 May Jan .23 Jan .10 .95 .4 15 13 11 9.9 9.2 21 57 45 16 38 72 68 18 11 12 913 e549 248 230 212 75 52 49 44 38 35 293 270 99 61 ___ 3584.1 119 913 9.2 47 7110 3.45 3.85 54.0 119 1995 12.9 1991 - 1995 1995 1994 16 1995 9 1992 6 1992 6 1992 6 1992 e Estimated RIO GUANAJIBO BASIN 50133600 RIO GUANAJIBO NEAR SAN GERMAN, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°07'18", long 67°03'56", at bridge on Highway 347, 2.2 mi (3.5 km) northwest of San German. DRAINAGE AREA.--45.5 mi 1 (117.8 km1 ). PERIOD OP RECORD.--Water years 1979 to current year. WATER QUALITY DATA, WATER YEARS OCTOBER 1994 TO SEPTEMBER 1995 383 DATE OCT 1994 24. .. DEC 21. .. FEB 1995 15.. . APR 25. .. JUN 22. .. SEP 15. .. DATE OCT 1994 24. .. DEC 21. .. FEB 1995 15. .. APR 25... JUN 22. .. SEP 15... TIME 1000 1045 1250 1025 0930 0645 HARD- NESS TOTAL (MG/L AS CAC03) 210 -- -- 270 -- 200 SILICA, DATE OCT 1994 24. . . DEC 21. .. FEB 1995 15. .. APR 25. .. JUN 22. .. SEP 15. .. K » non-ideal DIS- SOLVED (MG/L AS 6IO2) 32 -- -- 31 -- 35 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 73 34 8.1 7.2 7.2 30 CALCIUM DIS- SOLVED (MG/L AS CA) 23 -- -- 29 -- 21 SOLIDS, SUM OP CONSTI- TUENTS, DIS- SOLVED (MG/L) 276 -- -- 403 -- 295 SPE- CIFIC CON- DUCT- ANCE (US /CM) 441 600 686 662 B33 480 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 37 -- — 47 -- 35 SOLIDS, DIS- SOLVED (TONS PER DAY) 54.2 -- — 7.B4 -- 24.0 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.6 7.6 7.5 7.6 7.5 6.9 SODIUM, DIS- SOLVED (MG/L AS NA) 14 _- -- 49 -- 21 RESIDUE TOTAL AT 105 DBG. C, SUS- PENDED (MG/L) IB 5 <1 14 4 4 TEMPER- ATURE WATER (DEG C) 26.0 25.0 26.0 27.0 26.0 27.0 SODIUM AD- SORP- TION RATIO 0.4 — — 1 — 0.7 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.30 0.20 1.4 1.5 l.B O.B3 TUR- BID- ITY (NTU) 7.0 1.8 1.3 9.2 3.8 4.2 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 1.7 __ __ 6.1 __ 3.3 PHOS- PHORUS TOTAL (MG/L AS P) 0.220 0.270 0.590 0.970 0.680 0.310 OXYGEN, DIS- SOLVED (MG/L) 4.2 4.2 4.0 2.0 2.5 3.6 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 220 260 270 220 260 220 ARSENIC TOTAL (UG/L AS AS) <1 -- — 1 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 51 50 4B 25 30 45 SULFIDE TOTAL (MG/L AS S) <0.5 _- -- <0.5 __ ~~ BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 -- — OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 10 <10 16 18 27 16 SULFATE DIS- SOLVED (MG/L AS S04) 19 -- — 51 — 22 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 30 — -- 470 -- — COLI- FORM, FECAL, 0.45 UM-MF (COLS . / 100 ML) 2400 3300 2300 240 410 K630 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 17 -- -- 58 -- 26 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 870 K190 K130 460 K1200 280 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 -- -- 0.20 -- 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 8 -- -- 8 -- — 384 RIO GUANAJIBO BASIN 50133600 RIO GUANAJIBO NEAR SAN GERMAN, PR--Continued WATER QUALITY DATA, WATER YEARS OCTOBER 1994 SEPTEMBER 1995 DATE OCT 1994 24. . . DEC 21. .. FEB 1995 15. .. APR 25. .. JUN 22. .. SEP 15... COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 -- __ 30 -- -- IRON, TOTAL RECOV- ERABLE (UG/L AS FE) 570 __ __ 900 __ -- LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) <1 __ — 25 _- -- MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 50 __ __ 170 __ __ MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 — __ <0.10 — __ SELE- NIUM, TOTAL (UG/L AS SE) <1 -- __ <1 __ __ SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <1 — — <1 -- -- ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) <10 -- -- 20 -- -- CYANIDE TOTAL PHENOLS (MG/L TOTAL AS CN) (UG/L) <0.010 1 __ __ <0.010 <1 — __ METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) <0.02 __ -- 0.05 -- — RIO GUANA JIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR LOCATION. --Lat 18°09'36«, long 67005'08", Hydrologic Unit 21010003 at bridge on Highway 348, 0.5 mi southwest of Rosario plaza. DRAINAGE AREA. --18. 3 mi 2 (47.4 km2 ). WATER-DISCHARGE RECORDS PERIOD OP RECORD. --October 1985 to current year. GAGE. — Water- stage- recorder. Elevation of gage is 50.0 ft (15.2 m) , from topographic map • REMARKS. — Records fair except those for estimated daily discharges, which are poor. Gage-height and satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER DAILY MEAN VALUES DAY OCT NOV DEC JAN PEB MAR APR MAY JUN 1 e52 141 130 30 22 96 21 14 28 2 e74 84 179 29 22 53 21 13 24 3 e56 76 104 27 21 44 21 13 21 4 e42 60 69 27 21 148 20 17 21 5 e33 53 57 26 21 135 20 31 20 6 e58 48 50 27 20 123 20 55 19 7 e90 46 46 25 21 104 19 46 18 8 e!40 45 43 25 21 85 18 23 17 9 e!60 127 41 26 20 69 19 19 19 10 e!40 75 39 25 19 56 22 17 23 11 e212 64 37 24 19 51 21 18 19 12 e!62 48 36 23 18 43 26 23 17 13 e221 41 35 56 18 38 21 40 15 14 168 38 34 131 17 35 20 24 14 15 114 39 33 87 17 33 50 20 14 16 87 38 36 49 17 31 38 21 14 17 98 37 43 36 17 29 27 21 14 18 119 41 44 32 20 27 24 21 14 19 80 91 133 30 24 27 22 22 14 20 68 126 103 29 20 26 20 86 17 21 101 64 48 32 21 26 19 42 15 22 94 56 39 35 75 25 18 25 13 23 68 47 36 29 41 25 17 21 12 24 58 47 34 27 24 24 16 19 12 25 53 130 33 26 132 23 16 19 12 26 52 87 31 30 158 23 16 22 12 27 70 120 30 27 82 23 16 37 22 28 71 111 32 25 131 23 16 165 21 29 51 62 30 24 —— 22 16 80 15 30 65 51 29 23 —— 22 15 46 15 31 161 —— 30 23 —— 22 —— 36 --- TOTAL 3018 2093 1664 1065 1059 1511 635 1056 511 MEAN 97.4 69.8 53.7 34.4 37.8 48.7 21.2 34.1 17.0 MAX 221 141 179 131 158 148 50 165 28 MIN 33 37 29 23 17 22 15 13 12 AC-PT 5990 4150 3300 2110 2100 3000 1260 2090 1010 CFSM 5.32 3.81 2.93 1.88 2.07 2.66 1.16 1.86 .93 IN. 6.13 4.25 3.38 2.16 2.15 3.07 1.29 2.15 1.04 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1986 - 1995, BY WATER YEAR (WY) MEAN 108 71.5 31.9 21.7 18.8 23.5 23.8 47.1 43.6 MAX 206 117 53.7 34.4 37.8 77.0 57.7 122 91.1 (WY) 1986 1990 1995 1995 1995 1989 1989 1993 1993 MIN 33.2 16.1 9.92 15.1 8.55 10.1 11.9 15.8 12.0 (WY) 1992 1992 1992 1994 1992 1992 1991 1990 1992 SUMMARY STATISTICS FOR 1994 CALENDAR YEAR FOR 1995 WATER YEAR ANNUAL TOTAL 13960.1 17766 ANNUAL MEAN 38.2 48.7 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 257 May 16 520 Aug 22 LOWEST DAILY MEAN 9.3 Jul 1 12 Jun 23 ANNUAL SEVEN-DAY MINIMUM 10 Mar 19 13 Jun 20 INSTANTANEOUS PEAK FLOW 3740 Aug 22 INSTANTANEOUS PEAK STAGE 10.78 Aug 22 INSTANTANEOUS LOW FLOW 12 Jun 24 ANNUAL RUNOFF (AC-FT) 27690 35240 ANNUAL RUNOFF (CFSM) 2.09 2.66 ANNUAL RUNOFF (INCHES) 28.38 36.11 10 PERCENT EXCEEDS 90 107 50 PERCENT EXCEEDS 21 30 90 PERCENT EXCEEDS 11 17 e Estimated 1995 JUL 15 19 29 94 33 27 25 19 17 16 25 27 26 21 19 19 21 19 47 39 33 37 34 29 27 29 24 36 38 25 21 890 28.7 94 15 1770 1.57 1.81 41.7 75.2 1989 23.2 1990 (0.8 km) precipita AUG 20 20 22 19 51 51 31 23 22 22 20 19 18 17 18 104 79 107 108 59 36 520 193 140 121 87 58 45 38 34 30 2132 ; 68.8 520 17 4230 ^ 3.76 : 4.33 4 58.9 < 102 1989 : 25.1 : 1991 : WATER YEARS 1986 - : 48.9 70.6 30.8 1550 3.9 4.2 7480 13.64 3.7 35420 2.67 36.30 115 27 11 ; ; oct 7 : May 9 : May 6 : Aug 24 : Aug 24 : May 9 : :ion SEP 27 25 23 23 23 52 91 68 43 42 56 41 32 27 38 279 173 104 194 143 82 67 69 58 47 42 94 75 51 43 --- 132 1.1 279 23 230 .88 .33 4.5 157 993 2.7 986 995 993 992 985 992 992 988 988 992 385 386 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORHIGUEROS, PR--Continued WATER-QUALITY RECORDS PERIOD OP RECORD.--HATER YEARS 1979 TO CURRENT YEAR. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: OCTOBER 1985 TO SEPTEMBER 1994 INSTRUMENTATION.--US D-49 SEDIMENT SAMPLER SINCE OCTOBER 1985. AUTOMATIC SEDIMENT SAMPLER SINCE 1986 REMARKS.--sediment samples were collected by a local observer once daily during low flow and more than once daily during high flow events for concentration and particle size analyses. Sediment samples are collected periodically by survey staff. Automatic sediment sampler set to collect samples above 200 cfs. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATIONS! Maximum daily mean, 8,150 mg/L October 7, 1985; Minimum daily mean, 1 mg/L Several days. SEDIMENT LOADS: Maximum daily, 74,700 tons (67,800 tonnes) October 7, 1985; Minimum daily, 0.05 ton (0.04 Tonne) several days. EXTREMES FOR CURRENT YEAR 1995.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 2,930 mg/L July 4, 1995; Minimum daily mean, 1.0 mg/L November 24, 1994. SEDIMENT LOADS: Maximum daily, 5,990 tons (5,430 tonnes) September 16, 1995; Minimum daily 0.13 ton (0.12 tonne) November 24, 1994. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 20. .. DEC 22. .. FEB 1995 16. .. APR 26. .. JUN 22... SEP 14. .. DATE OCT 1994 20. .. DEC 22... FEB 1995 16... APR 26... JUN 22. .. SEP 14. .. TIME 0945 0920 0840 0910 1110 1050 HARD- NESS TOTAL (MG/L AS CAC03) 120 — — 140 -- 130 DIS- CHARGE, INST. CUBIC FEET PER SECOND 67 41 17 16 13 28 CALCIUM DIS- SOLVED (MO/L AS CA) 22 -- -- 27 -- 24 SPE- CIFIC CON- DUCT- ANCE (US/CM) 260 2 €7 236 286 320 278 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 16 -- -- 17 -- 16 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.9 7.6 7.7 7.7 7.9 7.2 SODIUM, DIS- SOLVED (MO/L AS HA) 6.8 -- -- 8.7 -- 7.8 TEMPER- ATURE WATER (DEG C) 23.0 22.0 22.5 24.0 25.0 26.0 SODIUM AD- SORP- TION RATIO 0.3 -- — 0.3 -- 0.3 TUR- BID- ITY (NTU) 2.4 1.5 0.40 1.1 1.3 3.3 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 1.7 -- -- 1.5 -- 2.5 OXYGEN, DIS- SOLVED (MG/L) 6.0 5.0 7.6 3.8 5.2 8.2 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 120 120 110 140 130 120 OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 69 60 86 44 62 101 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- 0.6 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 <10 <10 10 14 <10 SULFATE DIS- SOLVED (MG/L AS S04) €.2 -- -- 6.0 -- 6.2 COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) K170 2100 K160 K100 K120 K6200 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 7.0 -- -- 12 -- 7.7 STREP- TOCOCCI FECAL, (COLS. PER 100 ML) K1400 3600 K130 410 220 2500 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 -- -- <0.10 — <0.10 non-ideal count RIO GUANAJIBO BASIN DATE OCT 1994 20... DEC 22. .. FEB 1995 16. .. APR 26. .. JUN 22. .. SEP 14. .. DATE OCT 1994 20... DEC 22... FEB 1995 16. . . APR 26. . . JUN 22... SEP 14... 50136400 HATER QUALITY SOLIDS, SILICA, SUM OF SOLIDS, DIS- CONSTI- DIS- SOLVED TUBNTS, SOLVED (MG/L DIS- (TONS AS SOLVED PER SI02) (MG/L) DAY) 29 161 28.9 __ __ 30 186 8.24 __ 30 166 12.4 COPPER, IRON, LEAD, TOTAL TOTAL TOTAL RECOV- RECOV- RECOV- ERABLE ERABLE ERABLE (UG/L (UG/L (UG/L AS CU) AS FE) AS PB) <10 170 <1 __ __ <10 100 <1 __ RIO ROSARIO NEAR DATA, HATER YEARS RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 8 5 1 3 2 2 MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MM) 10 -- -- 10 -- NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 <0.20 <0.20 0.20 0.20 0.20 MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 -- __ <0.10 -- HORMIGUEROS , PR- - Cont inued OCTOBER 1994 TO SEPTEMBER 1995 BARIUM, BORON, CADMIUM PHOS- TOTAL TOTAL TOTAL PHORUS ARSENIC RECOV- RECOV- RECOV- TOTAL TOTAL ERABLE ERABLE ERABLE (MG/L (UG/L (UG/L (UG/L (UG/L AS P) AS AS) AS BA) AS B) AS CD) 0.040 <1 <100 30 <1 0.040 0.050 0.040 <1 <100 20 <1 0.040 0.030 SILVER, ZINC, SELE- TOTAL TOTAL NIUM, RECOV- RECOV- CYANIDE TOTAL ERABLE ERABLE TOTAL PHENOLS (UG/L (UG/L (UG/L (MG/L TOTAL AS SE) AS AG) AS ZN) AS CN) (UG/L) <1 <1 <10 <0.010 <1 __ __ <1 <1 <10 <0.010 9 __ :HRO- nuM, TOTAL RECOV- ERABLE (UG/L VS CR) 7 -- -- 4 -- - - ffiTHY- LENE BLUE ICTIVE SUB- STANCE (MG/L) <0.02 -- -- 0.04 -- 387 388 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR-- Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN DISCHARGE DAY (CFS) 1 2 3 4 5 6 7 B 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 e52 e74 e56 e42 e33 e58 e90 e!40 e!60 e!40 e212 e!62 e221 168 114 87 98 119 80 68 101 94 68 58 53 52 70 71 51 65 161 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) OCTOBER 18 17 17 17 17 17 79 199 256 210 1720 2190 523 354 84 53 105 123 38 29 207 151 100 66 44 39 56 70 34 76 638 e2 e2 e3 e2 el e2 e!6 e62 e!04 e85 e!650 e972 e577 169 27 12 29 44 8 5 102 39 18 10 6 7 14 15 4 20 902 .€ .9 .0 .2 .7 .0 .2 .3 .3 .4 .7 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) NOVEMBER MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) {MG/L) (TONS/DAY) DECEMBER 141 84 76 60 53 48 46 45 127 75 64 48 41 38 39 38 37 41 91 126 64 56 47 47 130 87 120 111 62 51 229 60 79 41 25 11 9 8 1040 727 30 13 11 9 8 7 6 5 277 118 15 16 3 1 796 97 269 153 29 17 93 15 17 6 3 1 1 1 647 156 5 1 1 266 49 2 2 770 27 235 53 5 2 .7 .6 .5 .1 .0 .5 .6 .2 .96 .85 .71 .60 .58 .5 .4 .35 .13 .0 .3 130 179 104 69 57 50 46 43 41 39 37 36 35 34 33 36 43 44 133 103 48 39 36 34 33 31 30 32 30 29 30 341 391 122 29 15 10 9 9 9 9 8 8 7 7 7 13 30 48 556 200 35 18 14 11 20 50 112 60 58 88 62 249 252 37 5 2 1 1 1 1 4 6 825 79 4 1 1 1 1 4 9 5 4 7 5 .5 .3 .4 .1 .0 .99 .91 .83 .77 .68 .63 .62 .8 .4 .2 .6 .9 .4 .0 .8 .2 .2 .2 .7 .0 .0 TOTAL 3018 4913.3 2093 2366.58 1517.13 e Estimated RIO GOANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGtJEROS, PR-- Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 389 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) (CPS) (MG/L) (TONS/DAY) JANUARY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 30 29 27 27 26 27 25 25 26 25 24 23 56 131 87 49 36 32 30 29 32 35 29 27 26 30 27 25 24 23 23 29 15 32 87 17 6 8 10 11 10 10 9 72 301 110 34 19 15 13 12 14 17 10 7 5 6 7 6 5 5 4 2 1 2 6 1 29 282 33 4 1 1 1 1 1 .4 .2 .4 .3 .2 .45 .54 .69 .75 .71 .65 .58 .7 .8 .3 .0 .91 .4 .7 .77 .52 .38 .46 .49 .43 .36 .30 .26 FEBRUARY 22 22 21 21 21 20 21 21 20 19 19 18 18 17 17 17 17 20 24 20 21 75 41 24 132 158 82 131 ___ ___ 3 2 3 4 5 7 9 7 5 4 3 3 3 4 4 4 3 3 3 3 3 237 40 8 426 516 99 369 ___ ___ .18 .13 .16 .21 .26 .36 .52 .41 .24 .18 .16 .16 .16 .17 .18 .16 .14 .16 .19 .16 .17 154 5.2 .52 726 489 28 304 ___ ___ MARCH 96 53 44 148 135 123 104 85 69 56 51 43 38 35 33 31 29 27 27 26 26 25 25 24 23 23 23 23 22 22 22 111 38 27 465 230 292 217 173 92 42 20 11 10 12 4 2 3 3 4 4 3 4 5 6 6 7 8 10 10 10 10 33 5. 3. 534 98 143 61 40 18 6. 2. 1. 1. 1. • . . . . . 5 2 1 8 3 1 1 31 20 22 25 28 25 22 25 31 36 40 45 52 59 60 60 59 1065 378.65 1059 1711.18 1511 954.50 390 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIG0EROS, PR-- Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CPS) (MG/L) (TONS/DAY) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 21 21 21 20 20 20 19 18 19 22 21 26 21 20 50 38 27 24 22 20 19 18 17 16 16 16 16 16 16 15 __- APRIL 9 9 8 8 8 8 9 9 10 10 10 8 6 4 52 66 10 8 8 8 8 6 4 3 6 12 13 10 8 6 ___ .54 .50 .46 .43 .43 .45 .45 .46 .51 .62 .61 .54 .31 .22 20 7.9 .75 .56 .47 .42 .40 .30 .21 .15 .25 .54 .54 .42 .33 .24 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) MAY MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) JUNE 14 13 13 17 31 55 46 23 19 17 18 23 40 24 20 21 21 21 22 86 42 25 21 19 19 22 37 165 80 46 36 5 4 5 7 25 40 23 7 6 4 6 8 22 12 12 11 10 9 7 162 35 15 10 10 11 11 23 489 91 20 9 .19 .15 .17 .45 2.1 9.3 3.7 .45 .29 .21 .27 .50 2.6 .80 .62 .61 .57 .49 .42 88 4.6 .99 .57 .50 .59 .68 4.7 566 25 2.5 .89 28 24 21 21 20 19 18 17 19 23 19 17 15 14 14 14 14 14 14 17 15 13 12 12 12 12 22 21 15 15 5 4 4 4 4 5 5 5 3 4 5 6 8 8 6 6 6 7 9 11 13 11 8 5 5 5 28 23 9 9 .36 .26 .23 .23 .23 .25 .24 .22 .15 .24 .25 .29 .34 .30 .25 .23 .23 .27 .32 .50 .52 .37 .25 .18 .16 .16 3.9 1.4 .38 .35 635 40.01 1056 718.91 511 13.06 RIO GOANAJIBO BASIN 391 50136400 RIO ROSARIO NEAR HORMIOTBROS, PR-- Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MEAN DISCHARGE DAY (CFS) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 TOTAL YEAR 15 19 29 94 33 27 25 19 17 16 25 27 26 21 19 19 21 19 47 39 33 37 34 29 27 29 24 36 38 25 21 890 17766 MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) JULY 11 14 14 2930 2680 349 63 14 10 10 11 12 13 15 14 13 12 11 135 75 59 36 20 17 16 10 5 20 26 10 7 —— MEAN DISCHARGE (CFS) MEAN CONCEN- SEDIMENT TRATION DISCHARGE (MG/L) (TONS/DAY) AUGUST 1. 1480 272 22 4. . . • . . 54 8. 5. 3. 1. 1. 1. 4. 2. • 1872. 24028. 46 73 1 5 73 44 44 74 87 91 82 72 68 67 58 1 2 5 9 3 2 78 31 0 9 70 42 70 45 20 20 22 19 51 51 31 23 22 22 20 19 18 17 18 104 79 107 108 59 36 520 193 140 121 87 58 45 38 34 30 2132 6 7 9 8 85 127 28 26 23 21 18 16 14 13 13 336 209 235 264 98 27 1190 471 95 40 23 13 7 9 13 21 —— 38 19 2 1 1 1 406 52 80 77 17 2 5990 254 36 13 5 2 1 1 7008 .30 .35 .53 .43 .3 .6 .4 .2 .98 .78 .69 .62 .61 .6 .4 .0 .89 .87 .2 .7 .45 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) SEPTEMBER 27 25 23 23 23 52 91 68 43 42 56 41 32 27 38 279 173 104 194 143 82 67 69 58 47 42 94 75 51 43 33 48 38 25 17 46 135 58 29 58 56 26 10 5 28 933 240 114 622 243 77 45 59 47 26 22 160 68 31 23 2. 3. 2. 1. 1. 12 61 13 4. 6. 13 3. 9. 1030 113 34 957 103 17 8. 15 7. 3. 2. 87 15 4. 2. 4 2 4 6 0 3 6 0 84 34 8 1 7 3 5 3 6 2132 2533.98 392 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGDEROS, PR--Continued WATER QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DATE OCT 1994 05. .. 31... 31. . . NOV 09... DEC 01. .. 19. .. MAR 1995 04. .. JUL 04. .. AU6 22. .. 22. .. DATE OCT 1994 05. . . 31. .. 31. .. NOV 09. .. DEC 01. .. 19... MAR 1995 04. .. JUL 04. .. AU6 22. . . 22. . . TIME 1802 1805 1825 1355 1723 2055 1659 1600 1431 1625 SED. SUSP. FALL DIAM. PERCENT FINER THAN .016 MM 51 41 56 60 18 66 47 43 38 58 DIS- CHARGE, INST. CUBIC FEET PER SECOND e!7 891 938 549 386 610 640 510 637 2940 SED. SUSP. FALL DIAM. PERCENT FINER THAN .031 MM €2 52 67 68 21 77 56 50 49 69 SEDI- MENT, SUS- PENDED (MG/L) 12300 7890 8120 2892 5112 4783 3980 4501 6185 9390 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 71 €4 80 81 25 88 66 62 €4 80 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) e564 19000 20600 4290 5330 7880 6880 6200 10600 74500 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .125 MM 91 82 93 93 29 96 75 76 76 92 SED. SUSP. FALL DIAM. PERCENT FINER THAN .002 MM 22 17 26 45 11 40 21 29 28 33 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .250 MM 98 94 98 98 33 98.6 83 83 82 97 SED. SUSP. FALL DIAM. PERCENT FINER THAN .004 MM 30 25 36 50 13 46 31 34 32 40 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .500 MM 99.3 97.8 99.5 99.4 45 99.4 91 88 86 98.7 SED. SUSP. FALL DIAM. PERCENT FINER THAN .008 MM 41 32 45 54 14 54 40 37 36 47 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN 1.00 MM 99.8 99.5 99.8 99.8 75 99.7 96.8 96.7 92 99.3 e Estimated RIO GUANAJIBO BASIN 393 50136400 RIO ROSARIO NEAR HORMIGDEROS , PR--Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DATE OCT 1994 11.. . 12... 21.. . 31.. NOV 25.. . DEC 02... 19. .. JAN 1995 14... FEB 26... 26.. . 26.. . 26.. . MAR 04... 04.. . APR 05.. . MAY 26.. . JUL 04.. . AUG 17.. . 22.. . 22.. . TIME 1600 1600 1617 1755 1621 1415 1940 1640 1555 1635 1605 1725 1640 1655 1701 1605 1640 1216 1436 1640 STREAM- FLOW, INSTAN- TANEOUS (CFS) 369 134 256 556 379 460 607 501 614 507 530 461 440 446 20 530 447 33 954 1230 SEDI- MENT, SUS- PENDED (MG/L) 2600 2400 1250 3970 2910 1460 2710 1210 2950 144 1640 2050 1430 1620 6 1640 3220 134 14630 1750 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 2730 666 664 5960 2960 1920 5900 1640 4690 197 2630 2550 1700 1950 0.4 2630 3690 12 37700 5610 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN .062 MM 82 76 65 72 53 69 82 ee 75 97 96 75 70 66 92 96 70 96 69 67 394 RIO GUANAJIBO BASIN 50138000 RIO GUANAJIBO NEAR HORMIGDEROS, PR LOCATION.--Lat 18°08'36", long 67<>0e'57", Hydrologic Unit 21010003, at bridge on Highway 100, 1.4 mi (2.3 km) west of Hormigueroa, and 2.0 mi (3.2 km) downstream from Rio Roaario. DRAINAGE AREA.--120 mi 1 (311 km 1 ). HATER-DISCHARGE RECORDS PERIOD OF RECORD.--Annual low-flow measurements 1959, monthly measurements April 1959 to November 1967, January 1973 to current year. GAGE.--Water-atage recorder. Datum of gage ia at mean aea level. Previoua to Nov. 7, 1980, at aite 0.3 mi (0.5 km) upstream at datum 7.36 ft (2.243 m) higher. REMARKS.--Records fair. Gage-height and precipitation satellite telemetry at atation. Daily diachargea affected by aewage treatment plant about 2.1 mi (3.4 km) upatream from gage. DISCHARGE, CUBIC FEET PER SECOND, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES DAY NOV JAN MAR APR JUL AUG SEP 1 306 441 2 331 272 3 168 638 4 131 454 5 167 326 6 203 241 7 361 206 8 581 356 9 676 772 10 640 512 11 600 347 12 486 266 13 445 222 14 609 190 15 304 168 16 231 151 17 256 139 18 338 159 19 255 345 20 392 501 21 388 291 22 315 249 23 261 179 24 227 160 25 449 251 26 358 220 27 360 261 28 280 416 29 240 280 30 215 254 31 427 --- TOTAL 11000 9267 MEAN 355 309 MAX 676 772 MIN 131 139 AC-FT 21820 18380 CFSM 2.96 2.57 IN. 3.41 2.87 STATISTICS OF MONTHLY MEAN MEAN 483 419 MAX 1254 1518 (WY) 1986 1978 MIN 97.5 42.7 (WY) 1992 1992 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 261 339 431 549 401 293 246 223 213 184 154 142 133 125 117 111 125 117 139 262 130 112 108 97 95 89 86 85 78 73 71 5589 180 549 71 11090 1.50 1.73 DATA 130 422 1976 15.4 1992 FOR 70 69 68 65 61 62 56 52 55 73 53 50 86 175 238 136 91 79 72 68 64 80 64 61 58 60 57 54 51 48 46 2322 74.9 238 46 4610 .62 .72 44 42 41 40 39 38 42 42 37 37 35 34 32 32 31 31 33 41 78 78 56 188 139 66 160 407 288 412 ___ ___ --- 2543 90.8 412 31 5040 .76 .79 FOR HATER YEARS 1973 58.9 110 1993 13.8 1973 48.0 96.1 1993 13.9 1977 324 152 135 251 324 242 240 253 157 180 209 113 83 71 80 68 54 49 45 41 40 36 32 30 29 28 25 23 23 22 22 3381 109 324 22 6710 .91 1.05 - 1995 47.0 244 1989 10.6 1977 1994 CALENDAR YEAR 40083 110 772 13 15 79500 .92 12.43 305 42 18 Nov 9 Jun 23 Mar 20 22 22 22 23 24 23 23 24 33 30 33 52 36 40 33 75 84 58 43 36 33 32 31 29 27 28 27 32 30 26 --- 1031 34.4 84 22 2040 .29 .32 24 23 24 41 88 183 339 182 118 138 119 75 102 79 107 94 69 60 58 274 159 74 59 51 48 52 84 306 274 145 122 3571 115 339 23 7080 .96 1.11 99 82 68 60 53 51 46 43 44 67 49 42 37 35 34 34 32 31 28 30 26 26 24 23 23 23 36 133 50 39 1368 45.6 133 23 2710 .38 .42 35 32 66 156 94 56 67 48 41 37 76 114 71 58 46 48 40 34 45 109 98 149 141 83 82 81 67 61 119 73 61 2288 73.8 156 32 4540 .62 .71 52 48 51 47 51 117 66 48 42 43 38 35 32 30 30 170 141 267 377 253 151 317 909 413 286 221 171 145 130 118 110 4909 158 909 30 9740 1.32 1.52 100 89 79 74 70 86 152 171 108 127 149 175 116 98 97 830 595 350 410 497 267 208 178 164 129 115 414 439 218 172 --- 6677 223 830 70 13240 1.85 2.07 , BY HATER YEAR (WY) 69.3 316 1989 16.1 1977 FOR 1995 53946 148 909 22 22 1500 18. 107000 1. 16. 352 84 31 175 636 1980 12.7 1977 HATER YEAR Aug 23 Mar 30 Mar 28 Sep 16 47 Sep 16 23 72 107 504 1979 9.23 1977 102 240 1984 26.4 1976 HATER 197 402 69. 35000 5. 5. 128000 28. 4. 142500 1. 22. 430 76 21 220 757 1988 42.3 1976 YEARS 1973 - ,6 Sep 16 , 0 Jun 18 ,5 Jun 17 Sep 16 ,50 Sep 16 ,6 Jun 22 ,64 ,27 474 2075 1975 95.4 1991 1995 1979 1994 1975 1977 1977 1975 1975 1977 RIO GUANAJIBO BASIN 50138000 RIO GUANAJIBO NEAR HORMIGUEROS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Hater years 1958 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 395 DATE OCT 1994 21. .. DEC 22. .. FEB 1995 16. .. APR 26. .. JUN 23. .. SEP 14. .. DATE OCT 1994 21. .. DEC 22. .. FEB 1995 16... APR 26. .. JUN 23. .. SEP 14. .. TIME 1015 0750 1045 1120 0755 1245 HARD- NESS TOTAL (MG/L AS CAC03) 150 -- -- 200 -- 170 SILICA, DATE OCT 1994 21... DEC 22. .. FEB 1995 16. .. APR 26. .. JUN 23... SEP 14. .. K = non-ideal DIS- SOLVED (MG/L AS SIO2) 27 -- -- 32 __ 32 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 416 115 31 29 23 97 CALCIUM DIS- SOLVED (MG/L AS CA) 23 -- -- 31 -- 25 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 219 -- -- 262 __ 234 SPE- CIFIC CON- DUCT- ANCE (US /CM) 320 418 465 461 500 430 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 22 — — 30 — 27 SOLIDS, DIS^ SOLVED (TONS PER DAY) 246 — — 20.4. __ 61.3 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.2 7.5 7.7 7.6 7.6 7.1 SODIUM, DIS- SOLVED (MG/L AS NA) 9.3 -- -- 18 -- 13 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 128 12 5 10 4 11 TEMPER- ATURE WATER (DEG C) 25.0 24.0 24.5 27.0 25.0 28.0 SODIUM AD- SORP- TION RATIO 0.3 — — 0.6 — 0.4 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.60 0.20 <0.20 0.40 0.40 0.51 TUR- BID- ITY (NTU) 69 7.3 4.2 3.4 3.8 8.1 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.4 -- __ 2.3 -- 2.2 PHOS- PHORUS TOTAL (MG/L AS P) 0.300 0.120 0.190 0.220 0.230 0.180 OXYGEN, DIS- SOLVED (MG/L) 4.6 4.0 6.0 4.0 4.6 3.5 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 180 200 210 190 200 170 ARSENIC TOTAL (UG/L AS AS) 2 — -- <1 -- — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 54 46 70 49 55 44 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- 0.6 -- ~~ BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -_ -- <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 32 <10 11 <10 <10 18 SULFATE DIS- SOLVED (MG/L AS SO4) 15 — _- 16 — 16 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 40 — — 60 -- — COLI- FORM, FECAL, 0.45 UM-MF (COLS . / 100 ML) 5100 K7400 2700 K82 330 K1400 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 12 -- _- 19 -- 17 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 8100 41000 K160 290 860 K1200 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 -- — <0.10 — <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 23 -- -- 4 -- -- 396 RIO GUANAJIBO BASIN 50138000 RIO GUANAJIBO NEAR HORMIGUEROS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 21. .. DEC 22. . . FBB 1995 16. .. APR 26. .. JUN 23. .. SEP 14. .. COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS FB) AS PB) AS MN) AS HG) AS SB) AS AG) AS ZN) AS CN) (UG/L) 3600 350 290 50 <0.10 <0.10 (MG/L) 50 <0.010 <1 <0.02 •eO.010 <1 <0.02 PESTICIDE ANALYSES CHLOR- DANE, P,P'- P,P'- ENDO- TBCH- ODD DOT DI- DI- SULFAN, PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, BLDRIN I DATE TIME 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) JUN 1995 23... 0755 <0, ENDRIN WATER UNFLTRD DATE REC (UG/L) JUN 1995 23... <0.010 PARA- THION, DATE TOTAL (UG/L) .100 <0. BTHION, TOTAL (UG/L) <0.010 PCNS UNFILT RECOVER (UG/L) 010 <0 HEPTA- CHLOR, TOTAL (UG/L) <0.010 PBR- THANE TOTAL (UG/L) .100 <0 HEPTA- CHLOR BPOXIDE TOTAL (UG/L) <0.010 TOX- APHENE, TOTAL (UG/L) .010 <0 LINDANE TOTAL (UG/L) <0.010 TOTAL TRI- THION (UG/L) .010 <0 MALA- THION, TOTAL (UG/L) <0.010 2,4-D, TOTAL (UG/L) .010 0 METH- OXY- CHLOR, TOTAL (UG/L) <0.010 2,4,5-T TOTAL (UG/L) .010 <0 METHYL PARA- THION, TOTAL (UG/L) •eO.010 2, 4-DP TOTAL (UG/L) .010 <0.010 MIRBX, TOTAL (UG/L) <0.010 SILVEX, TOTAL (UG/L) JUN 1995 23.. . <0.010 <0.100 <0.100 <1.00 <0.010 0.030 <0.010 <0.010 <0.010 L.AWC S >*eltH»<p;'. . xr" **-~K>S~-^ 1 '~~~^ „ 0^,4 > \ 7 . T "7 / r6 0^ \l J ,' ,- / ./ ^ 5 -O f»«J»M.^ --.K >%« t..M EXPLANATION A 144° SURFACE-WATER STATION AND NUMBER T 1388 QUALITY-OF-WATER STATION AND NUMBER • 1415 LAKE-ELEVATION STATION AND NUMBER / } .JH.. 01 23456 KILOMETERS 01 234 MILES Figure 26.--Rio Yaguez and Rio Grande de Anasco basins. co <0 N 398 RIO YAGUEZ BASIN 50138800 RIO YAGUEZ NEAR MAYAGUEZ, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°12'31", long 67°07'07", at steel-truss bridge on unnumbered paved road about 800 ft (244 m) south of Highway 106, 1.8 mi (2.9 km) west of Highways 106 and 352 junction, and 1.4 mi (2.3 km) east-northeast from Mayaguez plaza. DRAINAGE AREA.--6.7 mi» (17.3 km'). PERIOD OF RECORD.—Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 20. .. DEC 21... FEE 1995 16. .. APR 25. .. JtJN 22. .. SEP 14... DATE OCT 1994 20. .. DEC 21. .. FEE 1995 16. .. APR 25. .. JtJN 22. .. SEP 14. .. TIME 1205 1215 1220 1215 1250 1430 HARD- NESS TOTAL (HG/L AS CACO3 ) 120 -- — 150 -- 130 SILICA, DATE OCT 1994 20... DEC 21... FEE 1995 16. .. APR 25. .. JtJN 22. .. SEP 14. .. K = non-ideal DIS- SOLVED (MG/L AS SI02) 30 — -- 32 __ 32 count DIS- CHARGE, INST. CUBIC FEET PER SECOND 14 4.8 2.7 1.6 2.7 7.1 CALCIUM DIS- SOLVED (MG/L AS CA) 33 -- -- 41 -- 35 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 172 -- -_ 209 __ 211 SPE- CIFIC CON- DUCT- ANCE (US/CM) 265 250 333 323 356 320 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 9.4 -- — 12 -- 11 SOLIDS, DIS- SOLVED (TONS PER DAY) 6.49 — __ 0.92 __ 4.06 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.8 7.6 7.9 7.8 7.7 7.2 SODIUM, DIS- SOLVED (MG/L AS NA) 10 -_ _- 13 __ 11 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 4 <1 1 8 3 3 TEMPER- ATURE WATER (DEG C) 24.0 23.0 24.5 26.0 25.5 28.0 SODIUM AD- SORP- TION RATIO 0.4 -- -- 0.5 — 0.4 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 <0.20 <0.20 0.20 0.20 0.21 TUR- BID- ITY (NTU) 3.3 3.4 0.30 0.80 2.5 2.9 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.2 -- -- 2.2 __ 2.6 PHOS- PHORUS TOTAL (MG/L AS P) 0.050 0.030 0.060 0.040 0.020 0.050 OXYGEN, DIS- SOLVED (MG/L) 5.4 4.6 6.8 6.2 6.2 6.4 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CAC03 120 110 160 150 150 170 ARSENIC TOTAL (UG/L AS AS) 1 -- __ <1 — -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 62 53 eo 75 75 81 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 -- ~~ BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -_ -- <100 -- — OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 <10 <10 <10 <10 <10 SULFATE DIS- SOLVED (MG/L AS S04) 6.4 — — 8.2 -- 7.4 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 30 — -- 40 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 550 K7300 220 330 210 470 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 8.7 -- -- 11 -- 9.6 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- — STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 910 810 K200 490 420 K1700 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 — -- • 0.10 -- <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 — — <1 -- — RIO YA6UEZ BASIN 50138800 RIO YAGUEZ NEAR MAYAGUEZ, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 399 DATE OCT 1994 20. . . DEC 21. .. FEB 1995 16. .. APR 25. .. JUN 22. . . SEP 14... COPPER, TOTAL RECOV- ERABLE (UG/L AS CU) <10 — — <10 — — IRON, TOTAL RECOV- ERABLE (UO/L AS FE) 580 -- -- 120 -- -- LEAD, TOTAL RECOV- ERABLE (UG/L AS PB) <1 -- — <1 -- -- MANGA- NESE, TOTAL RECOV- ERABLE (UG/L AS MN) 20 -- -- 10 __ -- MERCURY • TOTAL RECOV- ERABLE (UG/L AS HG) <0.10 -- -- <0.10 -- -- SELE- NIUM, TOTAL (UG/L AS SB) <1 -- -- <1 __ -- SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) <1 -- -- <1 -- -- ZINC, TOTAL RECOV- ERABLE (UG/L AS ZN) <10 -- -- <10 -- -- CYANIDE TOTAL PHENOLS (MG/L TOTAL AS CN) (UO/L) <0.010 2 __ __ <0.010 <1 __ __ METHY- LENE BLUE ACTIVE SUB- STANCE (MG/L) 0.03 -- — 0.29 -- -- 400 RIO GRANDE DE ANASCO BASIN 50141500 LAGO GUAYO AT DAHSITE NEAR CASTANER, PR LOCATION.--Lat 18°12'46", long 66<>50'06", Hydrologic Unit 21010003, at Guayo Dam on Rio Guayo, 1.1 mi (1.8 km) southwest of Lago Yahuecas, 2.6 mi (4.2 km) southwest of Lago Prieto, 2.1 mi (3.4 km) north of Castaner, and 6.0 mi (9.6 km) west of Adjuntas. DRAINAGE AREA.--9.60 mi* (24.86 km1 ). ELEVATION RECORDS PERIOD OF RECORD.--April 1980 to January 1985, June 1989 to current year. Guayo near Castafter. GAGE.--Water-stage recorder. Datum of gage is mean sea level. Prior to October 1994, published as Lago REMARKS.--Lago Guayo was completed in 1956. The dam is on Rio Guayo and is the largest in the southwestern Puerto Rico project. The maximum storage is 17,400 ac-ft (21.5 hmj ) for power and irrigation. The dam is a concrete gravity structure with a total length of 555 ft (169 m), a maximum structural height of 190 ft (58 m), and a maximum width at the base of 145 ft (44 m) . The ungated overflow spillway with a crest elevation of 60.00 ft (18.29 m) and a crest length of 220 ft (67 m) was designed to pass a maximum flood of 30,200 ft'/s (855 mVs) at a reservoir elevation of 70.00 ft (21.34 m) . Timber flashboards that were added to increase storage capacity were subsequently removed and their use discontinued. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 1462.43 ft (445.75 m), May 27, 1980; minimum elevation recorded, 1415.43 ft (431.42 m), June 2, 1990, but may have been less during period of no gage-height record June 2-5, 1990. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 1460.78 ft (445.24 m), May 10; minimum elevation recorded 1431.71 ft (436.38 m), Sept. 4. Capacity Table (based on data from Puerto Rico Water Resources Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX MIN OCT 1434.71 1434.24 1433.92 1433.74 1433.87 1434.36 1434.99 1436.38 1436.57 1436.97 1437.21 1438.23 1438.57 1438.99 1439.49 1439.82 1440.20 1441.23 1441.79 1441.30 1440.81 1440.85 1440.41 1440.42 1440.77 1441.10 1441.41 1441.72 1441.96 1442.22 1442.51 1442.51 1433.74 1415 1449 NOV 1442.65 1443.19 1443.98 1444.32 1444.58 1444.81 1445.03 1445.25 1445.00 1444.69 1444.84 1445.07 1443.90 1443.72 1443.30 1442.07 1441.88 1441.98 1443.25 1444.07 1444.38 1444.08 1443.73 1443.93 1444.21 1444.49 1444.78 1444.93 1445.20 1445.45 --- 1445.45 1441.88 3,960 1460 13,550 10,660 1465 15,000 ELEVATION (FEET NGVD) , WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY OBSERVATION AT 24:00 VALUES DEC 1445.80 1446.31 1446.66 1446.93 1447.17 1447.39 1447.57 1447.64 1447.80 1447.97 1448.13 1448.13 1448.06 1448.02 1448.17 1448.57 1448.93 1449.15 1449.38 1449.94 1450.59 1450.86 1451.10 1451.34 1451.54 1451.73 1451.91 1452.09 1452.26 1452.40 1452.60 1452.60 1445.80 JAN 1452.75 1452.89 1452.96 1453.07 1453.22 1453.39 1453.55 1453.65 A A 1452.32 1451.64 1451.26 1450.43 1450.43 1450.51 1450.28 1450.47 1450.41 1450.14 1450.31 1450.48 1450.61 1450.75 1450.88 1451.19 1451.43 1451.47 1451.42 1451.55 1450.58 ___ FEB 1449.84 1449.75 1449.86 1450.00 1450.12 1450.24 1450.34 1450.50 1450.61 1450.72 1450.77 1450.88 1450.99 1451.08 1451.21 1451.30 1451.40 1451.52 1451.65 1451.78 1452.00 1452.71 1453.15 1452.70 1453.85 1456.78 1458.76 1458.86 ___ ___ --- 1458.86 1449.75 MAR 1459.06 1458.76 1458.26 1458.04 1458.39 1458.56 1458.20 1458.77 1459.14 1459.59 1460.04 1459.98 1459.87 1459.76 1459.59 1459.40 1459.19 1459.23 1459.29 1458.97 1458.83 1459.00 1459.16 1459.30 1459.47 1459.62 1459.44 1459.18 1458.91 1458.64 1458.50 1460.04 1458.04 APR 1458.50 1458.59 1458.72 1458.85 1458.97 1459.03 1459.15 1459.20 1459.35 1459.22 1458.79 1458.73 1458.87 1458.99 1459.16 1459.59 1460.51 1460.16 1460.03 1460.07 1460.07 1460.07 1460.06 1460.06 1459.66 1459.78 1459.59 1459.58 1459.68 1459.79 --- 1460.51 1458.50 MAY 1459.89 1459.99 1460.02 1460.16 1459.94 1459.62 1460.39 1460.23 1460.77 1460.39 1460.13 1460.71 1460.68 1460.54 1460.56 1460.35 1459.53 1459.19 1458.52 1459.06 1458.65 1458.20 1457.99 1458.28 1458.20 1458.52 1458.83 1459.36 1459.64 1460.04 1458.92 1460.77 1457.99 JON 1458.71 1458.62 1458.82 1458.53 1457.74 1457.49 1457.64 1457.88 1457.38 1456.90 A A A 1456.64 1456.83 1456.86 1456.96 1457.16 1456.99 1456.62 1456.04 1455.43 1455.72 1455.89 1456.14 1455.40 1456.11 1456.17 1455.82 1455.55 --- ___ JUL 1455.51 1455.63 1455.54 1455.98 1455.84 1455.65 1455.44 1455.01 1454.75 1454.27 1454.32 1453.90 1453.14 1452.06 1451.59 1451.06 1449.41 1448.02 1446.55 1445.07 1443.76 1443.93 1443.49 1442.25 1441.83 1441.05 1441.14 1441.43 1441.02 1441.35 1440.56 1455.98 1440.56 AUG 1440.09 1439.85 1439.91 1439.84 1439.28 1439.28 1438.52 1438.32 1438.07 1437.84 1437.06 1436.45 1436.60 1436.52 1435.69 1435.73 1435.41 1435.54 1436.06 1435.76 1434.85 1434.68 1435.11 1435.19 1435.06 1435.37 1435.12 1434.63 1434.16 1433.99 1433.42 1440.09 1433.42 SEP 1433.32 1432.62 1432.30 1431.71 1432.28 1434.10 1433.93 1433.17 1433.50 1433.47 1434.16 1434.61 1434.96 1435.50 1436.19 A A A 1453.91 1453.82 1453.89 1453.58 1453.73 1454.06 1454.04 1453.74 1454.80 1455.11 1454.25 1453.32 --- ___ ___ A No gage-height record 401 RIO GRANDE DE ANASCO BASIN 50143000 RIO ORANDE DE AftASCO NEAR LARES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°15'26", long 66°55'00", at bridge on Highway 124, 0.7 mi (1.1 km) downstream from confluence of Rio Blanco and Rio Prieto, and 3.7 mi (6.0 km) southwest of Lares plaza. DRAINAGE AREA.--26.3 mi* (68.1 km1 ) this does not include 36.2 mi 1 (93.8 km1 ) which contributes only dur- ing high floods, and 3.5 mi 1 (9.1 km 1 ) which contributes only part of its storm runoff. PERIOD OF RECORD.--Water years 1959-68, 1970 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 18. .. DEC 09. .. FEB 1995 16. .. APR 18. .. JUN 15. .. SEP 18. .. DATE OCT 1994 18... DEC 09. .. FEB 1995 16. . . APR 18... JUN 15. . . SEP 18. . . DATE OCT 1994 18... DEC 09. .. FEB 1995 16. .. APR 18... JTJN 15. . . SEP 18. .. TIME 1315 1240 0755 1245 1110 1405 HARD- NESS TOTAL (MG/L AS CAC03) 110 -- — 100 -- 95 SILICA, DIS- SOLVED (MG/L AS SI02) 28 -- __ 22 -- 30 DIS- CHARGE, INST. CDBIC FEET PER SECOND 124 24 17 233 44 110 CALCIUM DIS- SOLVED (MG/L AS CA) 29 __ _- 27 -- 26 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 162 -- -- 150 -- 152 SPE- CIFIC CON- DUCT- ANCE (US /CM) 247 306 318 248 293 250 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 8.0 __ — 8.2 -- 7.3 SOLIDS, DIS- SOLVED (TONS PER DAY) 54.1 — __ 94.3 -- 45.1 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.9 8.2 7.6 8.0 8.0 7.0 SODIUM, DIS- SOLVED (MG/L AS NA) 9.2 __ __ 9.8 -_ 9.6 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 42 4 1 40 5 3 TEMPER- ATURE WATER (DEG C) 24.5 24.0 22.0 25.5 24.5 27.0 SODIUM AD- SORP- TION RATIO 0.4 __ __ 0.4 -- 0.4 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.40 0.30 <0.20 0.40 <0.20 0.28 TUR- BID- ITY (NTU) 30 4.4 1.0 29 1.4 18 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.5 __ __ 3.4 __ 2.2 PHOS- PHORUS TOTAL (MG/L AS P) 0.070 0.040 0.050 0.070 0.030 0.090 OXYGEN, DIS- SOLVED (MG/L) 8.3 9.7 7.3 7.8 8.2 7.5 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CAC03 95 120 130 100 110 90 ARSENIC TOTAL (UG/L AS AS) 1 — -- <1 — -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 99 114 84 97 100 95 SULFIDE TOTAL (MG/L AS S) <0.5 __ -- <0.5 -- "" — BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- -- <100 __ -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 13 <10 <10 14 <10 10 SULFATE DIS- SOLVED (MG/L AS SO4) 18 __ -- 8.6 -- 14 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 20 __ -- 10 -- — COLI- FORM, FECAL, 0.45 UM-MF ' (COLS . / 100 ML) 3100 K50 K120 2400 R160 K890 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 10 __ __ 11 -- 8.7 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- __ <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 3500 K110 210 10000 260 K2100 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 -_ -- <0.10 -- <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 -- -- <1 — -- K = non-ideal count 402 RIO GRANDE DE ANASCO BASIN 50143000 RIO GRANDE DE ANASCO NEAR LARES, PR—Continued HATER-QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 18. .. DEC 09. .. FEB 1995 16. .. APR 18. . . JUN 15. .. SEP 18. .. COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CO) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) 20 1200 1300 100 130 <0.10 <0.10 <0.010 <0.010 (MG/L) <0.02 0.02 RIO GRANDE DE ANASCO BASIN 50144000 RIO GRANDE DE ANASCO NEAR SAN SEBASTIAN, PR LOCATION.--Lat 18°17'05", long 67°03'05", Hydrologic Unit 21010003, on left bank, at downstream side of bridge on Highway 108, 0.4 mi (0.6 km) downstream from Quebrada La Zumbadora, 4.4 mi (7.1 km) northwest of Las Marias, 5.4 mi (8.7 km) southwest of San Sebastian. DRAINAGE AREA.--94.3 mi 1 (244.2 km2 ), does not include 36.2 mi 1 (93.8 km2 ) which contributes only during high floods, and 3.5 mi 1 (9.1 km 1 ) which contributes only part of its storm runoff. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--Harch 1963 to current year. GAGE.--Water-stage recorder. Datum of gage is 103.72 ft (31.614 m) above mean aea level (Puerto Rico Department of Public Works bench mark). Previous to Oct. 30, 1975, at site 600 ft (180 m) upstream at same datum. REMARKS.--Records fair except those for estimated daily dischages, which are poor. Transbasin diversion (except during floods) to Rio Yauco basin for hydroelectric power and irrigation above Lago Guayo, Yahuecas, and Prieto, combined useable storage 17,300 acre-ft (21.3 hm3 ) . Limited storm runoff is contributed to basin by 3.5 mi 1 (9.1 km 1 ) above Rio Toro Diversion dam. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 403 DAY DEC 1 239 600 2 337 378 3 218 297 4 166 191 5 148 170 6 300 195 7 467 152 8 724 144 9 732 233 10 610 262 11 540 178 12 2550 214 13 933 143 14 1010 127 15 526 120 16 330 115 17 358 125 18 574 244 19 373 304 20 440 1340 21 1080 273 22 485 182 23 329 198 24 285 188 25 256 482 26 256 731 27 322 267 28 385 422 29 247 229 30 213 200 31 250 —— TOTAL 15683 8704 MEAN 506 290 MAX 2550 1340 MIN 148 115 AC-FT 31110 17260 CFSM 5.36 3.08 IN. 6.19 3.43 STATISTICS OF MONTHLY MEAN MEAN 664 436 MAX 1467 746 (WY) 1993 1982 MIN 344 197 (WY) 1983 1994 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 766 1290 423 271 226 205 166 161 152 147 142 230 201 144 133 142 998 1010 233 710 458 268 210 187 172 167 164 159 147 140 138 9960 321 1290 133 19760 3.41 3.93 DATA 226 482 1966 103 1992 FOR 129 127 124 123 118 119 113 109 109 111 109 103 171 177 159 300 139 118 111 106 102 155 110 99 97 163 148 110 101 96 95 3951 127 300 95 7840 1.35 1.56 FOR WATER 139 215 1970 83.6 1965 93 91 90 89 88 86 84 92 88 89 87 81 78 81 79 77 74 73 73 73 82 99 166 132 390 435 596 528 ___ ___ --- 4094 146 596 73 8120 1.55 1.62 YEARS 1963 107 161 1981 62.3 1992 1100 461 447 498 421 745 389 535 403 251 277 207 191 163 145 134 127 122 119 114 113 107 105 101 100 98 94 93 88 83 82 7913 255 1100 82 15700 2.71 3.12 - 1995 103 271 1972 54.4 1965 1994 CALENDAR YEAR 79278 217 2550 59 66 157200 2. 31. 523 123 70 Oct 12 Apr 14 Apr 9 30 27 79 77 76 72 73 74 70 68 73 96 80 126 84 73 68 124 174 402 198 114 95 96 95 90 88 87 67 62 70 61 —— 3012 100 402 61 5970 1.06 1.19 59 58 83 66 216 344 349 297 295 1480 1230 477 1290 1180 432 994 402 223 1250 588 320 169 124 99 195 642 1640 1130 622 492 607 17353 560 1640 58 34420 5.94 6.85 639 318 477 262 710 321 563 323 450 1080 427 312 224 327 820 1230 1120 363 672 408 257 212 192 176 165 180 170 283 159 161 --- 13001 433 1230 159 25790 4.60 5.13 138 170 150 143 215 548 271 154 134 123 215 914 410 239 179 161 146 137 135 130 213 186 375 179 191 139 124 122 164 126 128 6659 215 914 122 13210 2.28 2.63 116 141 173 121 108 141 157 114 133 228 147 102 94 126 105 117 201 311 549 341 191 677 602 249 246 183 138 120 108 102 96 6237 201 677 94 12370 2.13 2.46 92 e87 e88 101 91 244 887 530 415 306 418 597 362 162 134 3830 998 562 317 404 315 353 600 368 212 228 897 673 308 239 14818 494 3830 87 29390 5.24 5.85 , BY WATER YEAR (WY) 145 313 1971 49.3 1968 FOR 1995 111385 305 3830 58 66 14200 11. 56 220900 3. 43. 654 178 87 372 1084 1986 63.7 1967 WATER YEAR Sep 16 May 2 Apr 28 Oct 12 07 Oct 12 May 2 24 94 287 815 1979 71.2 1977 272 657 1979 111 1990 WATER 309 460 189 19400 32 35 140000 33 31 223500 3 44 652 185 74 354 936 1979 152 1967 YEARS 1963 Sep Apr Apr Sep .90 Sep Apr .27 .45 599 1422 1984 206 1983 - 1995 1979 1967 16 1975 18 1965 14 1965 16 1975 16 1975 19 1965 e Estimated 404 RIO GRANDE DE ANASCO BASIN 50144000 RIO GRANDE DE ANASCO NEAR SAN SEBASTIAN, PR--Continued (National stream-quality accounting network station) WATER-QUALITY RECORDS PERIOD OP RECORD.—Water years 1963 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 26.. . JAN 1995 18.. . APR 24. .. JUL 19. .. DATE OCT 1994 26. .. JAN 1995 16. .. APR 24. .. JUL 19. . . DIS- PH OXYGEN, COLI- CHARGE, SPE- WATER DIS- FORM, STREP- HARD- INST. CIPIC WHOLE SOLVED FECAL, TOCOCCI NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- 0.45 FECAL, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT UM-MF (COLS. (MG/L SOLVED TIME PER ANCE ARD WATER ITY SOLVED SATUR- (COLS./ PER AS (MG/L SECOND (US/CM) UNITS) (DEC C) (NTU) (MG/L) ATI ON) 100 ML) 100 ML) CACO3) AS CA) 0935 233 1020 115 1450 92 1145 136 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 9.1 9.2 10 9.5 SOLIDS, SODIUM, DIS- SOLVED (MG/L AS NA) 6.9 6.9 9.1 6.2 NITRO- GEN, DIS- NO2+NO3 DATE OCT 1994 26... JAN 1995 18. .. APR 24. .. JUL 19. .. SOLVED (TONS PER DAY) 97.5 46.4 40.7 56.0 DIS- SOLVED (MG/L AS N) 0.900 0.960 0.780 0.630 240 249 259 242 SODIUM AD- SORP- TION RATIO 0.4 0.4 0.4 0.4 NITRO- GEN, AMMONIA DIS- SOLVED (MG/L AS N) <0.015 0.020 0.020 0.030 7.7 7.8 6.0 8.3 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 1.6 1.7 1.7 1.6 NITRO- GEN, AMMONIA DIS- SOLVED (MG/L AS NH4) -_ 0.03 0.03 0.03 25.0 22.0 28.0 26.5 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CAC03 100 100 110 110 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.20 <0.20 0.20 0.20 6.3 3.4 1.8 4.2 SULFATE DIS- SOLVED (MG/L AS SO4) 9.7 9.5 9.3 9.6 PHOS- PHORUS TOTAL (MG/L AS P) 0.040 0.040 0.040 0.040 7.9 6.4 9.2 8.0 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 6.9 7.0 6.3 6.7 PHOS- PHORUS DIS- SOLVED (MG/L AS P) 0.030 0.030 0.030 0.030 94 94 118 100 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 <0.10 <0.10 0.10 PHOS- PHORUS ORTHO, DIS- SOLVED (MG/L AS P) 0.020 0.030 0.020 0.020 510 480 60000 K160000 K64 370 SILICA, DIS- SOLVED (MG/L AS SIO2) 30 27 29 26 PHOS- PHATE, ORTHO, DIS- SOLVED (MG/L AS PO4) 0.06 0.09 0.07 0.10 K120 K60 SOLIDS, RESIDUE AT 160 DEG. C DIS- SOLVED (MG/L) 155 156 163 151 ALUM- INUM, DIS- SOLVED (UG/L AS AL) 20 20 <10 20 110 28 110 27 110 29 110 26 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) 159 155 163 149 BARIUM, DIS- SOLVED (UG/L AS BA) 36 34 35 37 K = non-ideal count RIO GRANDE OB ANASCO BASIN 50144000 RIO GRANDE DE ANASCO NEAR SAN SEBASTIAN, PR--CONTINUED (NATIONAL STREAM-QUALITY ACCOUNTING NETWORK STATION) WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 405 DATE OCT 1994 26. .. JAN 1995 18. .. APR 24. .. JUL 19. .. COBALT, IRON, LITHIUM DIS- DIS- DIS- SOLVED SOLVED SOLVED (UG/L (UG/L (UG/L AS CO) AS FE) AS LI) <3 14 <4 <3 26 <4 <3 10 4 <3 21 <4 MANGA- NESE, DIS- SOLVED (UG/L AS MN) 23 26 21 19 MERCURY DIS- SOLVED (UG/L AS HG) <0.1 0.2 0.2 0.2 PARTICLE-SIZE DISTRIBUTION DATE OCT 1994 26. .. JAN 1995 18... APR 24. .. TIME 0935 1020 1450 STREAM- PLOW, INSTAN- TANEOUS (CPS) 233 115 92 MOLYB- DENUM, DIS- SOLVED (UG/L AS MO) <10 10 <10 <10 NICKEL, DIS- SOLVED (UG/L AS NI) <1 <1 <1 <1 SELE- NIUM, SILVER, DIS- DIS- SOLVED SOLVED (UG/L (UG/L AS SB) AS AG) <1 <1.0 <1 <1.0 <1 <1.0 <1 <1.0 STRON- VANA- TIUM, DIUM, DIS- DIS- SOLVED SOLVED (UG/L (UG/L AS SR) AS V) 140 <6 130 <6 150 <6 120 <6 OF SUSPENDED SEDIMENT SEDI- MENT, SUS- PENDED (MG/L) 32 18 9 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) 20 5.6 2.2 SED. SUSP. SIEVE DIAM. PERCENT FINER THAN . 062mn 91 80 82 406 RIO GRANDE DE ANASCO BASIN 50146000 RIO GRANDE DE ANASCO NEAR ANASCO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18«16'00 M , long 67«08'05", at bridge on Highway 430, 0.2 mi (0.3 km) south of Espino and 1.4 mi (2.3 km) east-southeast from Afiasco plaza. DRAINAGE AREA.--139 mi' (360 km') this does not include 39.7 mi 2 (102.8 km 1 ), flow is divert* coast. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 Highway 109 at El rd to south DATE OCT 1994 27... DEC 23. .. FEB 1995 15. .. APR 25... JUN 23... SEP 19. . . DATE OCT 1994 27. .. DEC 23. .. FEB 1995 15. .. APR 25. .. JUN 23. .. SEP 19. . . DATE OCT 1994 27... DEC 23. .. FEB 1995 15. .. APR 25. .. JUN 23. .. SEP 19. .. TIME 1100 0915 1315 0730 1100 0900 HARD- NESS TOTAL (HO/L AS CACO3) 110 -- — 110 -- 95 SILICA, DIS- SOLVED (HO/L AS SI02) 31 -- -_ 27 -- 28 DIS- CHARGE, INST. CUBIC FEET PER SECOND E1200 251 97 108 289 E440 CALCIUM DIS- SOLVED (HO/L AS CA) 30 -- -- 27 -- 24 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (HO/L) 156 -- -_ 158 -- 140 SPE- CIFIC CON- DUCT- ANCE (US /CM) 245 234 252 260 240 230 MAGNE- SIUM, DIS- SOLVED (MO/L AS HO) 8.9 -- -- 9.5 — 8.5 SOLIDS, DIS- SOLVED (TONS PER DAY) E505 -- __ 46.1 -- E166 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.6 7.7 7.5 7.6 8.0 6.6 SODIUM, DIS- SOLVED (HG/L AS NA) 9.1 -_ __ 9.9 __ 8.4 RESIDUE TOTAL AT 105 DEO. C, SUS- PENDED (MO/L) 30 7 13 10 29 14 TEMPER- ATURE WATER (DEO C) 26.0 23.0 24.5 26.0 27.0 27.0 SODIUM AD- SORP- TION RATIO 0.4 — __ 0.4 — 0.4 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 <0.20 <0.20 0.20 0.23 0.26 TUR- BID- ITY (NTU) 17 21 6.4 6.1 16 33 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 1.7 __ __ 1.7 __ 2.3 PHOS- PHORUS TOTAL (MG/L AS P) 0.040 0.040 0.030 0.020 0.020 0.080 OXYGEN, DIS- SOLVED (HG/L) 7.4 7.7 8.4 6.6 7.0 6.1 ALKA- LINITY WAT WH TOT FET FIELD HG/L AS CACO3 100 98 110 110 100 87 ARSENIC TOTAL (UG/L AS AS) <1 — __ 1 — — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 90 88 100 81 88 76 SULFIDE TOTAL (MG/L AS S) <0.5 _- -- <0.5 -- ~- BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 -- __ <100 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 <10 10 <10 <10 12 SULFATE DIS- SOLVED (MG/L AS SO4) 8.6 -- -- 8.8 -- 9.7 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 20 -- __ 30 -- — COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 510 K960 K60 K120 240 K760 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 6.8 -- __ 8.2 -- 6.7 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -_ <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 350 K500 K20 K200 480 870 FLUO- RIDE, DIS- SOLVED (MG/L AS F) <0.10 — — <0.10 -- <0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 2 -- -- <1 — — E = Estimated K = non-ideal count RIO GRANDE DE ANASCO BASIN 50146000 RIO GRANDE DE ANASCO NEAR ANASCO, PR—Continued WATER-QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 407 COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL MBTHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) OCT 1994 27. .. DEC 23. . . FEB 1995 15... APR 25. .. JUN 23... SEP 19. .. 20 1300 80 150 40 <0.10 <0.10 <0.010 <0.010 (MG/L) <0.02 <0.02 PESTICIDE ANALYSES DATE JUN 1995 23.. . DATE JUN 1995 23.. . •DATE JUN 1995 23.. . CHLOR- DANE, P,P'- P,P'- ENDO- TBCH- ODD DOT DI- DI- SULFAN, PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I TIME 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) 1100 <0 ENDRIN HATER UNFLTRD RBC (UG/L) <0.010 PARA- THION, TOTAL (UG/L) .100 <0. BTHION, TOTAL (UG/L) <0.010 PCNS UNFILT RECOVER (UG/L) 010 <0 HEPTA- CHLOR, TOTAL (UG/L) <0.010 PER- THANE TOTAL (UG/L) .100 <0 HBPTA- CHLOR EPOXIDE TOTAL (UG/L) <0.010 TOX- APHENE, TOTAL (UG/L) .010 <0 LINDANE TOTAL (UG/L) <0.010 TOTAL TRI- THION (UG/L) .010 <0, MALA- THION, TOTAL (UG/L) <0.010 2,4-D, TOTAL (UG/L) .010 <0 METH- OXY- CHLOR, TOTAL (UG/L) <0.010 2,4,5-T TOTAL (UG/L) .010 <0. METHYL PARA- THION, TOTAL (UG/L) <0.010 2, 4-DP TOTAL (UG/L) ,010 <0.010 MIREX, TOTAL (UG/L) <0.010 SILVEX, TOTAL (UG/L) <0.010 <0.100 <0.100 <1.00 <0.010 <0.010 <0.010 <0.010 <0.010 408 THIS PAGE WAS LEFT BLANK INTENTIONALLY AGUADULA Drainage boundary uncertain J EXPLANATION ^1478 SURFACE-WATER STATION AND NUMBER T1476 QUALITY-OF-WATER STATION AND NUMBER Ass WELL AND WELL NUMBER LARES Figure 27.--Rio Culebrinas basin. 410 RIO CULEBRINAS BASIN 50147600 RIO CULEBRINAS NEAR SAN SEBASTIAN, PR WATER-QDALITY RECORDS LOCATION.--Lat 18°20'51", long 67°02'40", at bridge on Highway 423, 1.3 mi (2.1 km) south of Quebrada El Salto Bridge on Highway 111, and 2.1 mi (3.4 km) west of Central La Plata. DRAINAGE AREA.—58.2 mi 1 (150.7 km1 ). PERIOD OF RECORD.—Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 26. .. DEC 22. .. FEB 1995 15. .. APR 25. .. JUN 22. .. SEP 19. . . DATE OCT 1994 26. .. DEC 22. .. FEB 1995 15. .. APR 25. . . JUN 22. . . SEP 19. .. DATE OCT 1994 26. .. DEC 22. . . FEB 1995 15. . . APR 25. .. JUN 22. .. SEP 19. .. TIME 1255 1320 1510 1030 1640 1145 HARD- NESS TOTAL (MG/L AS CACO3) 140 — — 110 — 140 SILICA, DIS- SOLVED (M6/L AS SIO2) 24 — — 34 — 27 DIS- CHARGE, INST. CUBIC FEET PER SECOND 149 97 31 21 1BB 116 CALCIUM DIS- SOLVED (MG/L AS CA) 46 — — 36 — 47 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED (MG/L) IBS -- -- 196 -- 193 SPE- CIFIC CON- DUCT- ANCE (US /CM) 300 265 260 305 269 330 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 5.2 — — 5.4 — 5.5 SOLIDS, DIS- SOLVED (TONS PER DAY) 74.3 — -- 11.2 — 60.4 PH WATER WHOLE FIELD (STAND- ARD UNITS) B.O 7.8 8.3 7.8 8.0 6.7 SODIUM, DIS- SOLVED (MG/L AS NA) 9.4 _- -- 18 _- 11 RESIDUE TOTAL AT 105 DEC. C, SUS- PENDED (MG/L) 16 32 <1 5 41 22 TEMPER- ATURE WATER (DEG C) 25.0 23.0 24.0 25.0 27.0 27.0 SODIUM AD- SORP- TION RATIO 0.4 — — 0.7 — 0.4 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) <0.20 0.50 <0.20 0.30 0.30 0.20 TUR- BID- ITY (NTU) 15 50 2.9 3.7 26 9.5 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.2 __ -- 3.6 -- 2.3 PHOS- PHORUS TOTAL (MG/L AS P) 0.040 0.110 0.100 0.120 0.020 0.040 OXYGEN, DIS- SOLVED (MG/L) 8.0 7.6 10.4 7.6 7.4 6.2 ALKA- LINITY WAT WH TOT FET FIELD MG/L AS CACO3 130 110 110 120 110 130 ARSENIC TOTAL (UG/L AS AS) <1 — -- 1 -- — OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 95 87 123 92 93 77 SULFIDE TOTAL (MG/L AS S) <0.5 -- -- <0.5 -- — — BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 _- -- <100 — — OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) 14 22 16 <10 <10 <10 SULFATE DIS- SOLVED (MG/L AS SO4) 11 — -- 10 — 12 BORON, TOTAL RECOV- ERABLE (UG/L AS B) 30 — — 50 — — COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 4200 22000 480 260 520 2100 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 8.9 _- -- 17 -- 10 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 -- -- <1 -- — STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 860 22000 200 K160 760 710 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 — — 0.10 — 0.10 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) <1 — — <1 — — K = non-ideal count 411 RIO CULEBRINAS BASIN 50147600 RIO CULEBRINAS NEAR SAN SEBASTIAN, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 COPPER, IRON, TOTAL TOTAL RECOV- RECOV- ERABLE ERABLE DATE OCT 1994 25. .. DEC 22. .. FEB 1995 15. .. APR 25... JUN 22... SEP 19. .. (UG/L (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, MERCURY TOTAL TOTAL RECOV- ERABLE RECOV- ERABLE (UG/L (UO/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- CYANIDE ERABLE TOTAL (UO/L (MG/L METHY- LENB BLUE ACTIVE PHENOLS SUB- TOTAL AS CU) AS FE) AS PB) AS MN) AS HO) AS SE) AS AG) AS ZN) AS CN) (UQ/L) 450 280 40 40 <0.10 <0.10 <0.010 <0.010 STANCE (MG/L) 0.02 0.03 472 RXO COLEBRXNAS BASIN 50147800 RIO CULEBRINAS AT HIGHWAY 404 NEAR MOCA, PR LOCATION.--Lat 18°21'42", long 67«05'33", Hydrologic Dnit 21010003, on right bank, at bridge on Highway 404, 0.3 mi (0.5 km) downstream from Quebrada Yagruma, and 2.8 mi (4.5 km) southeast of Hoca. DRAINAGE AREA.--71.2 mi» (184.4 km»). WATER-DISCHARGE RECORDS PERIOD OP RECORD.--July 1967 to current year. GAGE.--Water-stage recorder. Elevation of gage is 45 ft (14 m) , from topographic map. REMARKS.--Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES JAN FEB APR MAY JUL 1 263 161 2 230 124 3 235 114 4 177 110 5 159 111 6 148 161 7 155 134 8 158 110 9 544 108 10 922 361 11 720 165 12 1030 131 13 303 121 14 349 105 15 252 102 16 159 97 17 179 96 18 273 114 19 162 102 20 391 269 21 1180 129 22 391 103 23 202 98 24 171 94 25 162 91 26 169 313 27 179 139 28 145 100 29 127 95 30 120 94 31 114 TOTAL 9769 4052 MEAN 315 135 MAX 1180 361 MIN 114 91 AC-FT 19380 8040 CFSM 4.43 1.90 IN. 5.10 2.12 STATISTICS OF MONTHLY MEAN MEAN 627 336 MAX 1086 799 (WY) 1973 1982 MIN 231 108 (WY) 1968 1979 SUMMARY STATISTICS ANNUAL TOTAL ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN LOWEST DAILY MEAN ANNUAL SEVEN-DAY MINIMUM INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 593 2330 241 159 139 130 126 175 128 120 116 661 168 122 113 108 131 157 102 102 224 185 95 85 80 85 92 79 76 72 70 7064 228 2330 70 14010 3.20 3.69 DATA 147 424 1982 72.1 1992 FOR 68 68 66 66 64 66 62 61 61 61 60 58 77 108 235 164 82 74 70 68 66 75 65 64 63 87 77 66 63 61 58 2384 76.9 235 58 4730 1.08 1.25 56 56 54 54 54 53 54 60 52 50 63 52 50 49 48 47 45 43 43 43 45 50 48 61 108 118 68 80 ___ ___ --- 1604 57.3 118 43 3180 .80 .84 FOR WATER YEARS 1967 77.3 151 1971 51.2 1979 69.4 243 1981 37.0 1992 297 2080 316 201 191 139 92 130 181 96 106 104 82 87 83 70 65 62 58 56 56 52 50 48 48 49 46 44 43 44 42 5018 162 2080 42 9950 2.27 2.62 - 1995 69.0 319 1981 30.4 1979 1994 CALENDAR YEAR 64573 177 3120 26 27 128100 2.48 33.74 284 94 38 Sep 21 Apr 14 Apr 10 41 41 41 40 39 40 42 41 47 64 46 118 60 48 42 42 69 80 44 38 36 34 35 34 33 34 46 48 42 37 --- 1402 46.7 118 33 2780 .66 .73 33 31 30 30 36 94 58 273 182 377 901 704 1990 2930 251 345 238 230 481 227 189 160 124 340 227 658 2870 4750 3490 777 867 23893 771 4750 30 47390 10.8 12.48 2310 577 457 1360 1080 617 1030 498 420 4000 832 807 440 1170 1140 1520 587 553 473 634 327 255 229 210 195 181 178 167 152 308 22707 757 4000 152 45040 10.6 11.66 206 158 152 145 1190 300 257 440 344 207 167 241 241 156 146 145 201 181 150 141 135 134 190 181 134 125 119 124 152 120 314 6896 222 1190 119 13680 3.12 3.60 339 235 181 145 131 845 299 228 202 171 144 117 109 103 182 163 142 189 233 166 157 143 118 112 107 101 97 90 87 86 86 5508 178 845 86 10930 2.50 2.88 105 81 84 89 81 159 824 215 138 154 149 254 184 137 104 1160 313 182 151 423 501 1500 647 349 197 917 378 2060 445 775 --- 12756 425 2060 81 25300 5.97 6.66 , BY WATER YEAR (WY) 136 621 1986 26.4 1970 FOR 1995 103053 282 4750 30 34 21600 26. 30 204400 3. 53. 639 130 46 476 2054 1986 96.7 1973 WATER YEAR May 28 May 3 Apr 29 May 28 49 May 28 May 3 97 84 387 769 1984 82.7 1974 300 847 1979 66.7 1994 WATER 291 457 179 13300 19 20 69000 36. 16 210900 4. 55. 600 135 42 327 831 1979 119 1970 YEARS 1967 - Oct 21 Apr 16 Apr 13 Sep 16 60 Sep 16 Apr 17 09 54 515 1350 1978 145 1986 1995 1986 1977 1972 1979 1979 1975 1975 1979 413 RIO CTJLEBRIHAS BASIN 50149100 RIO CTJLEBRINAS NEAR A6UADA, PR WATER-QOALITY RECORDS LOCATION.--Lat 18°24'03", long 67°09'40", at bridge on Highway 2, and 2.3 mi (3.7 km) northeast of Aguada plaza. DRAINAGE AREA.--97.0 mi 1 (251.2 km 1 )• PERIOD OP RECORD.--Water yeara 1958, 1970 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 26. . . DEC 22... PEB 1995 15. .. APR 25. .. JUN 23. .. SEP 19... DATE OCT 1994 26. .. DEC 22. .. PEB 1995 15... APR 25... JON 23... SEP 19. .. TIME 1430 1140 1620 1430 0850 1020 HARD- NESS TOTAL (H6/L AS CAC03) 160 -- -- 140 __ 150 SILICA, DATE OCT 1994 26. .. DEC 22... PEB 1995 15... APR 25. .. JON 23... SEP 19. .. K « non-ideal E = estimated DIS- SOLVED (H6/L AS SI02) 27 -- -- 35 — 25 count DIS CHARGE, INST. CUBIC FEET PER SECOND E320 E170 ESS E60 E340 E230 CALCIUM DIS- SOLVED (M6/L AS CA) 53 -- -- 44 __ 51 SOLIDS, SUM OP CONSTI- TUENTS, DIS- SOLVED (MG/L) 213 -- -- 220 -- 218 SPE- CIFIC CON- DUCT- ANCE (US/CM) 340 260 300 352 320 375 MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) 6.1 __ — 6.4 — 6.4 RESIDUE TOTAL AT 105 DEG. C, SUS- PENDED (MG/L) 70 514 9 15 102 106 PH WATER WHOLE FIELD (STAND- ARD UNITS) 7.8 7.5 7.5 7.7 7.6 6.9 SODIUM, DIS- SOLVED (MG/L AS NA) 12 __ __ 15 __ 12 NITRO- GEN, AM- MONIA + ORGANIC TOTAL (MG/L AS N) 0.20 1.4 0.20 0.50 0.54 0.42 TEMPER- ATURE WATER (DEG C) 25.0 23.0 25.0 30.0 26.5 27.0 SODIUM AD- SORP- TION RATIO 0.4 __ — 0.6 __ 0.4 PHOS- PHORUS TOTAL (MG/L AS P) 0.050 0.190 0.040 0.190 0.040 0.160 TUR- BID- ITY (NTU) 28 310 7.1 13 50 49 POTAS- SIUM, DIS- SOLVED (MG/L AS K) 2.2 __ __ 5.2 __ 3.5 ARSENIC TOTAL (UG/L AS AS) <1 __ -- 1 -- -- OXYGEN, DIS- SOLVED (MG/L) 6.8 7.7 5.6 5.4 6.8 3.6 ALKA- LINITY WAT WH TOT PET FIELD MG/L AS CAC03 150 140 130 150 130 160 BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) <100 — -- <100 -- -- OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) 81 88 67 72 84 45 SULFIDE TOTAL (MG/L AS S) <0.5 __ __ <0.5 __ — — BORON, TOTAL RECOV- ERABLE (UG/L AS B) 20 __ -- 40 -- -- OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) <10 43 17 16 14 16 SULFATE DIS- SOLVED (MG/L AS SO4) 11 -- -- 7.8 __ 12 CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) <1 — -- <1 -- -- COLI- FORM, FECAL, 0.45 UM-MF (COLS./ 100 ML) 3100 55000 42000 430 K6700 2000 CHLO- RIDE, DIS- SOLVED (MG/L AS CL) 12 -- -- 17 __ 12 CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) 2 -- -- <1 -- -- STREP- TOCOCCI FECAL, (COLS. PER 100 ML) 380 52000 730 3400 650 3300 FLUO- RIDE, DIS- SOLVED (MG/L AS F) 0.10 -- -- 0.10 __ 0.10 414 RIO COLBBRINAS BASIN 50149100 RIO CDLEBRINAS NEAR AGUADA, PR--Continued HATER-QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE OCT 1994 26. .. DEC 22. .. FEB 1995 15. . . APR 25. . . JUN 23. . . SEP 19. .. COPPER, TOTAL RECOV- ERABLE (UG/L IRON, TOTAL RECOV- ERABLE (UG/L LEAD, TOTAL RECOV- ERABLE (UG/L MANGA- NESE, TOTAL RECOV- ERABLE (UG/L MERCURY TOTAL RECOV- ERABLE (UG/L SELE- NIUM, TOTAL (UG/L SILVER, TOTAL RECOV- ERABLE (UG/L ZINC, TOTAL RECOV- ERABLE (UG/L CYANIDE TOTAL (MG/L PHENOLS TOTAL METHY- LENE BLUE ACTIVE SUB- STANCE AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) 10 1700 130 <0.10 10 860 <1 130 <0.10 <0.010 <0.010 (MG/L) <0.02 0.03 PESTICIDE ANALYSES CHLOR- DANE, P,P'- P,P'- ENDO- TECH- ODD DDT DI- DI- SULFAN, PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I DATE TIME 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) JUN 1995 23... 0850 <0 ENDRIN HATER UNFLTRD DATE REC (UG/L) JUN 1995 23... <0.010 PARA- THION, DATE TOTAL (tJG/L) .100 <0 ETHION, TOTAL (UG/L) <0.010 PCNS UNFILT RECOVER (UG/L) .010 <0 HEPTA- CHLOR, TOTAL (UG/L) <0.010 PER- THANE TOTAL (UG/L) .100 <0. HEPTA- CHLOR EPOXIDE TOTAL (UG/L) <0.010 TOX- APHENE, TOTAL (tJG/L) 010 <0 LINDANE TOTAL (UG/L) <0.010 TOTAL TRI- THION (UG/L) .010 <0 MALA- THION, TOTAL (UG/L) <0.010 2,4-D, TOTAL (UG/L) .010 <0 METH- OXY- CHLOR, TOTAL (UG/L) <0.010 2,4,5-T TOTAL (UG/L) .010 <0 METHYL PARA- THION, TOTAL (UG/L) <0.010 2, 4-DP TOTAL (UG/L) .010 <0.010 MIREX, TOTAL (UG/L) <0.010 SILVEX, TOTAL (UG/L) JUN 1995 23.. . <0.010 <0.100 <0.100 <1.00 <0.010 0.050 <0.010 <0.010 <0.010 VIEQUES, PR 50232000 QUEBRADA LA MINA NEAR ESPERANZA, VIEQUES, PR LOCATION.—Lat 18°06'54", long 65«28'15", Hydrologic Unit 21010006, on left bank 300 ft (91 m), west from state road 996, 1.4 mi (2.2 km) south of Cerro Martineau, 0.7 mi (1.1 km) eaat-northeaet of Colonia Puerto Real on road 201 and 1.2 mi (1.9 km) north of Bsperanza. DRAINAGE AREA.--0.68 mi' (1.76 km'). WATER-STAGE RECORDS PERIOD OF RECORD.--July 1991 to current year. GAGE.—Water-stage recorder. Elevation of gage is 98 ft (30 m), from topographic map. REMARKS.—Gage-height and precipitation satellite telemetry at station. All gage-heighta of 9.20 ft or lower are considered zero flow. 475 EXTREMES OBSERVED FOR PERIOD OF RECORD.—Maximum gage-height, 9.90 ft (3.018 m), June 29, (2.670 m). May 18-24, 1994. EXTREMES FOR CURRENT YEAR.--Maximum gage-height, 9.11 ft (2.777 m), Sept. 6, 16; minimum, GAGE HEIGHT, FEET, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES 30, 1993; minimum, 8.76 ft 8.79 ft (2.679 m) , Sept. 16, OCT NOV DEC JAN MAR APR MAY JUN AUG SEP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX MIN CAL YR WTR YR 8.83 8.83 8.83 8.83 8.83 8.83 8.83 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.61 8.81 8.61 8.81 8.82 6.83 8.61 1994 1995 8.82 8.82 8.82 8.82 8.82 8.82 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.61 8.81 8.81 --- 8.82 8.81 MEAN 8.62 MEAN 8.62 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.82 8.81 8.81 8.82 8.82 8.82 8.62 8.62 8.82 8.82 8.82 8.82 8.82 6.82 8.82 6.82 8.83 8.82 8.82 8.83 8.83 8.83 8.81 MAX 9.07 MAX 8.89 8.82 8.83 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.83 8.82 8.82 8.82 8.82 8.62 6.82 8.82 8.83 8.82 MIN 6.70 MIN 8.79 8.82 8.82 8.83 8.83 8.83 8.82 8.82 8.83 8.82 8.82 8.82 8.82 8.82 8.82 8.83 8.82 8.81 6.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 ___ ___ --- 8.83 8.81 MED 8.81 MED 8.82 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.82 8.81 8.81 8.81 8.81 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 6.82 8.82 8.62 8.82 8.81 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 --- 6.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.83 8.83 8.83 8.83 8.83 8.83 8.83 8.83 8.82 8.82 8.82 8.82 8.82 8.83 8.82 8.82 8.82 8.82 8.82 6.83 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 --- 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.83 6.83 8.83 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.82 8.83 8.82 6.82 8.82 8.82 8.83 8.82 8.82 8.82 8.82 8.82 8.82 8.83 8.83 8.83 8.82 8.82 8.82 8.81 8.81 8.82 8.82 8.82 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.83 8.81 8.81 8.81 8.81 8.81 8.81 8.82 8.80 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.81 8.89 8.82 8.79 8.79 8.79 8.79 8.80 8.80 8.80 8.80 8.80 8.80 8.80 8.79 8.60 --- 8.89 8.79 416 VIEQUES, PR 50233000 QUEBRADA PILON AT COLONIA PUERTO REAL, VIEQUES, PR LOCATION.--Lat 18°06'37", long 65°28'51", Hydrologio Unit 21010006, on left bank, 1.2 mi (1.9 k»), southeast of Cerro Sonadora, 1.2 mi (1.9 km) northwest of Esperanza, 0.4 mi (0.6 km) south of junction of Highways 895 and 201. DRAINAGE AREA.--0.67 mi 2 (1.74 km 2 ). WATER-STAGE RECORDS PERIOD OP RECORD.—JUly 1991 to current year. GAGE.--Water-stage recorder. Elevation of gage is 131 ft (40 m), from topographic map. REMARKS.--Gage-height and precipitation satellite telemetry at station. All gage-heights of 8.36 ft or lower are considered zero flow. EXTREMES FOR PERIOD OF RECORD.- -Maximum gage-height, 9.13 ft (2.783 m), July 23, 1993; minimum, 6.68 ft (2.036 m), Sept. 14, 15, 1993. EXTREMES FOR CURRENT YEAR.--Maximum gage-height, 8.91 ft (2.716 m), Sept 16; minimum, 7.22 ft (2.201 m), Feb. 19. GAGE HEIGHT, FEET, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DAILY MEAN VALUES OCT JAN FEB APR MAY JDN SEP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX MIN 7.26 7.26 7.27 7.27 7.27 7.28 7.28 7.25 7.29 7.29 7.25 7.25 7.29 7.26 7.29 7.26 7.26 7.30 7.25 7.25 7.24 7.24 7.24 7.24 7.24 7.25 7.25 7.25 7.25 7.26 7.26 7.30 7.24 7.26 7.26 7.26 7.26 7.26 7.26 7.27 7.28 7.25 7.25 7.25 7.25 7.25 7.24 7.25 7.25 7.25 7.25 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.25 7.26 ___ 7.28 7.24 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.26 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.24 7.24 7.23 7.24 7.24 7.24 7.24 7.24 7.25 7.24 7.24 7.24 ___ ___ --- 7.25 7.23 7.24 7.24 7.24 7.24 7.24 7.24 7.24 7.24 7.24 7.24 7.24 7.24 7.24 7.25 7.25 7.25 7.25 7.25 7.25 7.24 7.25 7.25 7.26 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.26 7.24 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 --- 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 --- 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.25 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.26 7.81 7.87 7.68 7.65 7.59 7.32 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.25 7.87 7.25 WTR YR 1995 MEAN 7.26 MAX 7.87 MIN 7.23 417 418 DISCHARGE AT PARTIAL-RECORD STATIONS As the number of streams on which streamflow information is likely to be desired far exceeds the number of stream-gaging stations feasible to operate at one time, the Geological Survey collects limited streamflow data at sites other than stream-gaging stations. When limited streamflow data are collected on a systematic basis over a period of years for use in hydrologic analyses, the site at which the data are collected is called a partial-record station. Data collected at these partial-record stations are useable in low-flow or floodflow analyses, depending on the type of data collected. In addition, discharge measurements are made at other sites not included in the partial- record program. These measurements are generally made in times of drought or flood to give better areal coverage to those events. Those measurements and others collected for some special reason are called measurements at miscellane- ous sites. Low-flow partial-record stations Measurements of streamflow in the areas covered by this report made at low-flow partial-record stations are given in the following table. These measurements were made during periods of base flow when streamflow is pri- marily from ground-water storage. These measurements, when correlated with the simultaneous discharge of nearby stream when continuous records are available, will give a picture of the low-flow potentiality of stream. Discharge measurements made at low-flow partial-records stations during water year 1995 PUBLICATION RECORD STATION NAME 50010520 Rio Guajataca above sewage plant at Lares, PR LOCATION AND BASIN Rio Guajataca basin Lat 18°18'13 H , long 66°52'34", Hydrologic Unit 21010001, at barrio Pueblo, 0.5 mi (0.8 km) downstream from Highway 111, 1.5 mi (2.4 km) northwest from Cerro Palma, and 0.5 mi (0.8 km) north of Lares plaza. DRAINAGE AREA mi 2 (km>) 5.40 (14.0) 4/04/95 6/07/95 1100 1215 STREAM- FLOW ftVs (mVs) 3.03 (0.086) 19.0 (0.538) 50013000 Rio Camuy near Lares, PR 50014000 Rio Criminales near Lares, PR 50014500 Rio Camuy off Highway 129 near Lares, PR 50020150 Rio Vacas near Adjuntas, PR 50020295 Rio Cidra at Adjuntas, PR 50020500 Rio Grande de Arecibo near Adjuntas, PR Rio Camuy basin Lat 18°17'49", long 66°49'31 H , 7.62 4/04/95 0830 9.08 Hydrologic Unit 21010001, at (19.7) (0.257) bridge on Highway 111, 1.1 mi 6/07/95 0915 43.8 (1.8 km) upstream from Rio (1.240) Criminales, 1.8 mi (2.9 km) downstream from Rio Angeles and Rio Piedras confluence, and 3.5 mi (5.6 km) east of Lares. Lat 18°17'57", long 66°49'22", 4.68 4/04/95 0915 5.51 Hydrologic Unit 21010001, at (12.1) (0.156) bridge on Highway 111, 0.7 mi 6/07/95 1000 29.4 (1.1 km) upstream from Rio (0.833) Camuy, and 3.7 mi (5.6 km) east of Lares. Lat 18°19'01", long 66°49'38", 13.6 4/04/95 0715 13.6 Hydrologic Unit 21010002, at (35.2) (0.385) barrio Callejones, 1.1 mi 6/07/95 0830 92.2 (1.8 km) downstream from Rio (2.611) Criminales, 1.9 mi (3.1 km) east from Cueva Pajita, and 4.0 mi (6.4 km) northeast from Lares. Rio Grande de Arecibo basin Lat 18°10'29", long 66°44'16 H , 3.10 4/06/95 1400 2.65 Hydrologic Unit 21010001, at (8.03) (0.075) barrio Garzas on Highway 522, 6/06/95 1245 11.3 0.6 mi (1.0 km) upstream from (0.320) Highway 135, 2.2 mi (3.5 km) north of Lago Garzas, and 1.2 mi (1.9 km) northwest of Adjuntas plaza. Lat 18«09'58 H , long 66°43'37 H , 6.67 4/06/95 1445 4.61 Hydrologic Unit 21010001, at (17.3) (0.130) Adjuntas, 0.1 mi (0.2 km) 6/06/95 1345 18.8 downstream from Highway 10, (0.532) 1.9 mi (3.1 km) northeast of Lago Garzas, and 0.3 mi (0.5 km) northwest of Adjuntas plaza. Lat 18°10'54 H , long 66°44'12", 12.7 4/06/95 1315 8.71 Hydrologic Unit 21010001, at (32.9) (0.247) bridge on Highway 135, 1.0 mi 6/06/95 1230 43.2 (1.6 km) upstream from Lago (1.223) Adjuntas, and 1.5 mi (2.4 km) northwest of Adjuntas plaza. 419 STATION NUMBER 50021000 STATION NAME 50021800 Rio Guaonica near tJtuado, PR DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations—Continued LOCATION AND BASIN Rio Pellejas at Central Pellejas, PR DRAINAGE AREA mi' (km1 ) Rio Orande de Arecibo basin Lat 18°12'07", long 66°42'16", 5.46 Hydrologic Unit 21010001, at (14.1) barrio Pellejas near Highway 524, 0.1 mi (0.2 km) upstream from unnamed tributary and diversion tunnel, 1.0 mi (1.6 km) upstream from Lago Pellejas, and 2.9 mi (4.7 km) northeast of Adjuntas plaza. Lat 18°15'18", long 66°43'47", 6.10 Hydrologic Unit 21010001, at (15.8) barrio Gua6nica 50 ft (15 m) off Highway 603, 0.5 mi (0.8 km) upstream from Rio Orande de Arecibo, 0.4 mi (0.6 km) downstream from Rio Roncador, and 2.2 mi (3.5 km) southwest of Utuado plaza. DATE 4/06/95 6/06/95 TIME 1200 1100 4/06/95 6/06/95 1100 1000 STREAM FLOWS ft'/s 3.23 (0.091) 13.6 (0.385) 4.24 (0.120) 54.4 (1.541) 50021900 50021905 Quebrada Arenas near Utuado, PR Rio Orande de Arecibo near Utuado, PR 50023000 Rio Vivi near Central Pellejas , PR 50024945 Rio Caguana on Highway 10 near Utuado, PR 50025165 Rio Caricaboa at Jayuya, PR 50025175 Rio Orande de Jayuya at Jayuya, PR Lat 18°15'40", long 66°43'19", 2.59 4/06/95 0945 1.16 Hydrologic Unit 21010001, at (6.71) (0.033) barrio Arenas on Highway 10, 6/05/95 1215 2.81 200 ft (61 m) upstream from (0.080) Rio Orande de Arecibo, and 1.5 mi (2.4 km) southwest of Utuado plaza. Lat 18<>15'46", long 66°43'15", 39.9 4/06/95 1015 8.28 Hydrologic Unit 21010001, at (103) (0.234) barrio Arenas, 200 ft (61 m) 6/05/95 1245 24.8 off Highway 10, 0.1 mi (0.2 km) (0.702) downstream from Quebrada Arenas, 1.7 mi (2.7 km) upstream from Rio Vivi, and 1.4 (2.2 km) southwest from Utuado plaza. Lat 18°12'52", long 66°40'25", 5.66 4/07/95 1315 3.27 Hydrologic Unit 21010001, at (14.6) (0.093) barrio Vivi Arriba on Highway 6/05/95 1415 9.51 605, 2.0 mi (3.2 km) upstream (0.269) from Lago Vivi, 2.1 mi (3.4 km) northeast from Lago Pellejas, and 1.3 mi (2.1 km) northwest from Cerro Prieto. Lat 18°18'09", long 66°42'20" 4.49 4/06/95 0900 1.49 Hydrologic Unit 21010001, at (11.3) (0.042) barrio Sabana Orande, 3.4 mi 6/06/95 0845 37.3 (5.5 km) southwest of Lago Dos (1.056) Bocas spillway, 2.2 mi (3.5 km) northeast from Parcelas Cayuco, and 2.4 mi (3.9 km) north of Utuado plaza. Lat 18°13'10", long 66°35'12", 4.22 4/07/95 0845 1.11 Hydrologic Unit 21010001, at (10.9) (0.031) barrio Veguitas on Highway 144, 6/08/95 1315 4.31 0.4 mi (0.6 km) upstream from (0.122) Rio Orande de Jayuya, 1.6 mi (2.6 km) northwest of Hacienda Oripinas, and 0.5 mi (0.8 km) •ast of Jayuya plaza. Lat 18°13'01", long 66°36'28", 18.8 4/07/95 0945 5.70 Hydrologic Unit 21010001, 1.5 (48.7) (0.161) mi (2.4 km) downstream from 6/08/95 1215 26.5 Rio Caricaboa, 1.4 (2.2 km) (0.750) upstream from Rio Zamas, 1.0 mi (1.6 km) southwest from Jayuya plaza. 50025600 Rio Jauca near Jayuya, PR Lat 18°11'16", long 66°38'25", Hydrologic Unit 21010001, at barrio Jauca on Highway 140, 1.7 mi (2.7 km) southeast from Cerro Prieto, 4.6 mi (7.4 km) southeast from Lago Pellejas, and 3.8 mi (6.1 km) southwest of Jayuya. 4.44 (11.5) 4/07/95 6/08/95 1100 1100 2.15 (0.061) 9.92 (0.281) 420 DISCHARGE AT PARTIAL-RECORD STATIONS STATION NUMBER 50025900 STATION NAME Rio Jauca at mouth near Jayuya, PR 50026050 Rio Caonillas above Lago Caonillas, PR 50026250 Rio Limon on Highway 613 near Tetuan, PR 50026350 Rio Limon above confluence with Rio Yunes, PR Low-flow partial-record stations—Continued LOCATION AND BASIN DRAINAGE AREA (km*) Rio Grande de Arecibo basin Lat 18°13'08", long 66°38'35", 7.14 4/07/95 1215 Hydrologic Unit 21010001, at (18.5) barrio Paso Palma on Highway 6/08/95 1015 140, 0.2 mi (0.3 km) upstream from Rio Grande de Jayuya, 2.5 mi (4.0 km) southeast from Lago Vivi, and 2.0 mi (3.2 km) south of Lago Caonillas. Lat 18°14'26", long 66°38'22'', 40.4 3/27/95 0845 Hydrologic Unit 21010001, at (105) barrio Caonillas Arriba, 300 5/25/95 0830 feet (91 m) off Highway 531, 700 ft (213 m) upstream from Lago Caonillas, and 3.3 mi (5.3 km) northwest of Jayuya plaza. Lat 18°16'57", long 66°35'52", 5.55 3/27/95 1230 Hydrologic Unit 21010001, at (14.4) barrio Tetuan on Highway 613, 5/25/95 0930 0.4 mi (0.6 km) upstream from Rio Naranjito, 1.3 mi (2.1 km) northwest from Cerro Magoyo, and 1.3 (2.1 km) from Escuela Segunda Unidad de Mameyes. Lat 18°19'26", long 66°36'42», 16.7 3/27/95 0745 Hydrologic Unit 21010001, 3.4 (43.2) mi (5.5 km) upstream from Lago 5/25/95 0630 Caonillas, 100 ft (30 m) upstream from Rio Yunes, and 4.0 mi (6.4 km) southwest of Florida plaza. STREAM FLOWS ftVs (mVs) 3.74 (0.106) 11.4 (0.323) 16.4 (0.464) 33.4 (0.946) 6.66 (0.189) 17.2 (0.487) 13.9 (0.394) 33.7 (0.954) 50026925 Rio Yunes at Fronton, PR 50026950 Rio Yunes at mouth near Mameyes Abajo, PR 50027900 Rio Tanama near Caguana, PR 50028100 Rio Tanama above Observatorio de Arecibo, PR 50028200 Rio Tanama at Esperanza, PR Lat 18°18'11", long 66°34'09", 9.63 3/27/95 1200 3.58 Hydrologic Unit 21010001, at (24.9) (0.101) barrio Fronton, 0.9 mi (1.4 km) 5/25/95 0915 10.1 southwest fxom Escuela Segunda (0.286) Unidad de Fronton, 2.9 mi (4.7 km) northeast fron Cerro Magoyo, and 4.2 mi (6.8 km) of Florida Plaza. Lat 18°19'30", long 66°36'39", 13.5 3/27/95 0700 6.17 Hydrologic Unit 21010001, 3.4 (35.0) (0.175) mi (5.5 km) upstream from Lago 5/25/95 0715 20.1 Caonillas, 100 ft (30 m) (0.569) upstream from Rio Limon, 1.5 mi (2.4 km) northwest from Hacienda Piedra Gorda, and 4.0 mi (6.4 km) southwest of Florida plaza. Lat 18°15'42», long 66°46'55", 10.8 4/03/95 1200 14.0 Hydrologic Unit 21010001, near (30.0) (0.396) barrio Caguana, 4.4 mi (7.1 km) 6/09/95 1115 39.0 upstream from Highway 111, 2.5 (1.104) mi (4.0 km) south of Pargue Ceremonial Indigena Caguana, and 2.1 mi (3.4 km) southeast of comunidad Angeles. Lat 18°20'22'', long 66°45'25", Indeter- 4/03/95 1000 25.5 Hydrologic Unit 21010002, at minate (0.722) barrio Esperanza, 0.5 mi 6/09/95 0845 137 (0.8 km) southwest from the (3.852) Observatorio de Arecibo, 3.2 mi (5.1 km) southeast of comunidad Bayaney, and 3.2 mi (5.1 km) northeast of Pargue Ceremonial Indigena Caguana. Lat 18°22'45", long 66°44'02", Indeter- 4/03/95 0830 40.1 Hydrologic Unit 21010002, at minate (1.136) barrio Esperanza, 0.9 mi (1.4 6/09/95 0730 211 km) upstream from Highway 623, (5.976) 200 ft upstream of AAA intake, 3.2 mi (5.1 km) west from Rio Grande de Arecibo, and 6.7 mi (11 km) southwest from Arecibo plaza. 421 STATION NUMBER STATION NAME 50029800 Rio Grande de Manati near Barranquitas, PR 50029900 Rio Grande de Manati near Corazal, PR 50030250 Rio Botijas near Carro, PR 50030300 Rio Botijas near Botijas, PR 50030600 Rio Orocovis at Orocovis, PR DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued LOCATION AND BASIN DRAINAGE AREA mi 2 (km2 ) Rio Grande de Manati basin Lat 18°14'00", long 66°18'53", 3.81 3/28/95 1245 Hydrologic Unit 21010001, at (9.87) barrio Barrancas, 300 ft (91 m) 5/30/95 1145 east of Highway 771, 2.4 mi (3.9 km) northeast from Cerro La Torrecilla, 0.7 mi (1.1 km) southwest of Cerro El Farallon, and 3.1 mi (5.0 km) from Barranquitas plaza. Lat 18°16'48", long 66°20'03», 13.2 3/28/95 1115 Hydrologic Unit 21010001, at (34.2) barrio Negros on Highway 568, 7/31/95 1000 0.2 mi (0.3 km) upstream from Highway 568, 1.7 mi (2.7 km) northeast of El Salto Grande, and 4.4 mi (7.1 km) southwest of Corozal plaza. Lat 18°11'45", long 66°21'09», 3.82 3/30/95 1130 Hydrologic Unit 21010001, at (9.89) barrio Palo Hincado, 200 ft 5/30/95 0830 (61 m) upstream from Highway 156, 100 ft (30 m) upstream from pumping station intake, 1.4 mi (2.2 km) southwest from Cerro La Torrecilla, and 3.1 mi (5.0 km) west of BarraiKjuitas plaza. Lat 18°14'15", long 66°22'36", 12.5 3/30/95 1045 Hydrologic Unit 21010001, at (32.4) barrio Botijas on Highway 548, 5/30/95 0930 0.5 mi (0.8 km) upstream from Rio Orocovis, 0.8 mi (1.3 km) north from Highway 156, and 1.1 mi (1.8 km) northeast of Orocovis plaza. Lat 18°13'58", long 66°23'23", 8.78 3/30/95 1015 Hydrologic Unit 21010001, at (22.7) Orocovis, 0.5 mi (0.8 km) 5/30/95 0745 downstream from Quebrada Los Saltos, 1.3 mi (21 km) upstream from Rio Botijas, and 0.3 mi (0.5 km) northeast of Orocovis plaza. STREAM FLOWS ftVs (mVs) 1.35 (0.038) 2.68 (0.076) 5.11 (0.145) 3.40 (0.096) 0.42 (0.012) 4.43 (0.125) 2.52 (0.071) 19.0 (0.538) 1.43 (0.040) 13.9 (0.394) 50031500 50032050 Rio Sana Muerto near Orocovis, PR Quebrada Riachuelo at mouth, PR 50032100 Quebrada Grande near Morovis, PR Lat 18°16'14", long 66°24'47", 3.68 3/29/95 1130 0.54 Hydrologic Unit 21010001, at (9.53) (0.015) barrio Pesas, 2.5 mi (4.0 km) 7/27/95 1130 2.15 southwest from Cerro Magueyes, (0.061) 2.5 mi (4.0 km) upstream from Rio Grande de Manati, and 4.0 mi (6.4 km) south of Morovis plaza. Lat 18°18'18«, long 66°26'15". 1.69 3/29/95 1015 0.34 Hydrologic Unit 21010001, at (4.38) (0.010) barrio San Lorenzo, 50 ft 5/31/95 1130 3.38 (15 m) off Highway 567, 0.2 (0.096) (0.3 km) upstream from Rio Grande de Manati, 1.0 mi (1.6 km) north from Cerro Avispa, and 2.5 mi (4.0 km) southwest of Morovis plaza. Lat 18°18'45», long 66°26'40", 2.63 3/29/95 1030 0.62 Hydrologic Unit 21010001, at (6.81) (0.018) barrio San Lorenzo, 50 ft 5/31/95/ 1200 1.21 (15 m) off Highway 567, 0.6 (0.034) mi (1.0 km) upstream from Rio Grande de Manati, 2.3 mi (3.7 km) southeast from Ciales, and 2.6 (4.2 km) southwest from Morovis plaza. 422 STATION NUMBER STATION NAME 50032400 Rio Toro Negro on Highway 157 at Cacaos, PR 50032700 Rio Matrullas at mouth, PR 50033000 Rio Toro Negro near Ciales, PR 50033500 Rio Bauta near Divisoria, PR 50034500 50035600 Rio Bauta at Pozas, PR Rio Cialitos at Cialitos, PR 50035700 Rio Cialitos on Highway 614 near Ciales, PR DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued LOCATION AND BASIN DRAINAGE AREA mi a (km>) Rio Grande de Manati basin Lat 18°13'57", long 66°30'46", 11.8 Hydrologic Unit 21010001, at (30.6) barrio Cacaos on Highway 157, 0.5 mi (0.8 km) upstream from Quebrada Palma, 2.2 mi (3.5 km) northeast of Los Tres Picachos, and 5.3 mi (8.5 km) northeast of Jayuya plaza. Lat 18°15'29", long 66°30'04", 3.66 Hydrologic Unit 21010001 at (9.48) barrio Cacaos, 100 ft (30 m) upstream from Rio Toro Negro, 0.8 mi (1.3 km) east from Cerro Vista Alegre, and 2.6 mi (4.2 km) south from Cerro Gordo. Lat 18°17'20", long 66°29'06", 25.2 Hydrologic Unit 21010001, at (65.3) barrio Toro Negro on Highway 615, 0.6 mi (1.0 km) south from Escuela Segunda Unidad de Pesas, 2.3 mi (3.7 km) north- west from Cerro Cedro, and 3.7 mi (6.0 km) southwest from Ciales plaza. Lat 18°11'45°, long 66°26'30" Hydrologic Unit 21010001, at barrio Bauta Abajo, 2 . 6 mi (4.2 km) southeast from Lago Matrullas, 1.9 mi (3.1 km) northeast from Cerro El Malo, 4.0 mi (6.4 km) southwest of Orocovis plaza. Lat 18°17'47", long 66°27'35", 28.2 Hydrologic Unit 21010001, at (73.0) barrio Pozas, 100 ft (30 m) upstream from Rio Toro Negro, 4.0 mi (6.4 km) southwest of Morovis, and 2.9 mi (4.7 km) southeast of Ciales plaza. Lat 18°14'29", long 66°31'30", 3.18 Hydrologic Unit 21010001, at (8.24) barrio Cialitos, 0.3 mi (0.5 km) north of Highways 149 and 566 intersection, 2.0 mi (3.2 km) northeast from Los Tres Picachos, and 4.7 mi (7.6 km) northeast of Jayuya plaza. Lat 18°17'13", long 66°30'53", 6.66 Hydrologic Unit 21010001, at (17.2) barrio Pesas on Highway 614, 1.0 mi (1.6 km) southwest from Cerro Gordo, 1.8 mi (2.9 km) north of Cerro Vista Alegre, and 6.4 mi (10 km) southeast of Florida plaza. DATE 329/95 5/26/95 3/29/95 5/26/95 3/28/95 5/26/95 TIME 0700 0730 0800 0845 1115 0945 3/31/95 5/31/95 7/31/95 3/28/95 7/27/95 3/28/95 7/27/95 0715 1100 1245 1015 0800 0930 0845 STREAM FLOWS ftVs (mVs) 2.78 (0.079) 11.5 (0.326) 1.24 (0.035) 7.48 (0.212) 7.27 (0.206) 34.3 (0.971) 8.60 (22.3) 3/30/95 5/31/95 7/31/95 0845 0800 0800 0.61 (0.017) 62.6 (1.773) 6.48 (0.184) 3.94 (0.112) 104 (2.945) 20.6 (0.583) 1.40 (0.040) 2.10 (0.059) 3.77 (0.107) 5.43 (0.154) 50035950 Rio Cialitos at Highway 649 at Ciales, PR 50037200 Rio Grande de Manati near Manati, PR Lat 18°20'18", long 66°28'28", 17.0 3/28/95 0830 4.91 Hydrologic Unit 21010001, at (44.0) (0.139) Ciales, 100 ft (30 m) upstream 7/27/95 1030 11.4 from bridge on Highway 649, (0.323) 0.7 mi (1.1 km) upstream from Rio Grande de Manati, and 0.4 mi (0.6 km) west of Ciales plaza. Lat 18°24'52", long 66°29'37", Indeter- 3/28/9S/ 0730 43.2 Hydrologic Unit 21010002, at minate (1.223) barrio Rio Arriba Poniente, 8/01/95 0800 98.2 100 ft (30 m) off Highway 149, (2.781) 1.2 mi (1.9 km) southwest of comunidad Sabana Seca, 5.1 mi (8.2 km) upstream from Highway 2, and 1.0 mi (1.6 km) south of Manati plaza. 423 STATION NUMBER 50038295 50038302 50038317 50038345 STATION NAME Rio de Los Negros at •outh at Corozal, PR Rio Corozal above sewage plant at Corozal, PR Rio Cibuco at Cibuco, PR Rio Mavilla on Highway 164 near Corozal, PR 50038375 Rio Mavilla on Highway 821 near Maricao, PR DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued LOCATION AND BASIN DRAINAGE AREA DATE TIME (km') Rio Cibuco basin Lat 18°20'29", long 66°19'08", 4.04 3/31/95 0745 Hydrologic Unit 21010001, at (10.5) Corozal, 100 ft (30 m) 5/31/95 0730 upstream from Rio Corozal, 0.3 mi (0.5 km) upstream from Highway 159, and 0.1 mi (0.2 km) southwest of Corozal plaza. Lat 18°20'52", long 66°19'43", 9.75 3/31/95 0930 Hydrologic Unit 21010001, at (25.2) barrio Cibuco, 0.8 mi (1.3 km) 5/31/95 0915 upstream from Rio Cibuco, 0.7 mi (1.1 km) downstream from Highway 159, and 0.8 mi (1.3 km) northwest of Corozal plaza. Lat 18°20'54", long 66<>20'09", 5.05 3/31/95 0845 Hydrologic Unit 21010001, at (13.1) barrio Cibuco, 0.3 mi (0.5 km) 5/31/95 0815 upstream from Rio Corozal, 1.8 mi (2.9 km) southeast from Escuela Cienegueta, and 1.3 mi (2.1 km) northwest of Corozal plaza. Lat 18°19'07", long 66°17'21", 7.78 3/31/95 0700 Hydrologic Unit 21010001, at (20.2) barrio Palmarejo on Highway 5/31/95 0630 164, 0.6 mi (1.0 km) southwest from Escuela Segunda Unidad de Palmarejo, 1.3 mi (2.1 km) downstream from Quebrada La Jacinta, and 2.5 mi (4.0 km) southeast of Corozal plaza. Lat 18°22'11", long 66°20'02", 16.5 3/31/95 1115 Hydrologic Unit 21010002, at (42.7) barrio Abras on Highway 821, 5/31/95 1145 1.4 mi (2.2 km) upstream from Rio Cibuco, 1.3 mi (2.1 km) southwest from Cerro Santa Barbara, and 2.2 mi (3.5 km) northwest of Corozal plaza. STREAM FLOWS ft3 /s (mVs) 0.91 (0.026) 3.81 (0.108) 2.73 (0.077) 12.9 (0.365) 1.77 (0.050) 5.88 (0.166) 4.12 (0.117) 10.1 (0.286) 6.33 (0.179) 16.0 (0.453) 50038420 Rio Cibuco on Highway 620 near Vega Alta, PR 50038550 Rio Unibon above sewage plant at Unibon, PR 50038590 Rio Las Carreras at Unibon near Morovis, PR 50038650 Rio Unibon off Highway 160 near Almirante Sur, PR Lat 18°24'08", long 66°20'39", 38.8 3/31/95 1200 13.8 Hydrologic Unit 21010001, at (100) (0.391) barrio Candelaria on Highway 5/31/95 1300 40.3 620, 3.6 mi (5.8 km) down- (1.144) stream from Rio Mavilla, 6.2 mi (10 km) northwest from Toa Alta, and 1.2 mi (1.9 km) southwest of Vega Alta plaza. Lat 18°20'00", long 66<>22'18", 1.63 3/30/95 0800 0.66 Hydrologic Unit 21010001, at (4.22) (0.019) barrio Unibon, 0.7 mi (1.1 km) 6/01/95 0630 1.51 upstream from Rio Las Carreras, (0.043) 2.5 mi (4.0 km) northeast from 7/26/95 1200 0.81 Morovis, and 3.6 mi (5.8 km) (0.023) southwest of Corozal plaza. Lat 18°19'36", long 66°22'47", 2.65 3/30/95 0845 0.47 Hydrologic Unit 21010001, at (6.86) (0.013) barrio Unibon, 1.3 mi (2.1 km) 6/01/95 0715 1.71 upstream from Highway 159, 2.8 (0.048) mi (4.5 km) northeast of Cerro Quiros, and 1.9 mi (3.1 km) east of Morovis plaza. Lat 18°21'05", long 66°23'12", 7.52 3/30/95 1115 1.38 Hydrologic Unit 21010002, at (19.5) (0.039) barrio Almirante Sur, 0.4 mi 6/01/95 1030 3.94 (0.6 km) downstream from (0.112) Quebrada Monte Llano, 1.9 mi (3.1 km) upstream from Rio Morovis, and 2.2 mi (3.5 km) northeast of Morovis plaza. 424 STATION NUMBER 50038718 STATION NAME Rio Morovis above sewage plant near Morovis, PR DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations—Continued LOCATION AND BASIN Rio Cibuco basin Lat 18°20'12", long 66°25'15" Hydrologic Unit 21010002, at barrio Morovis Norte, 0.3 mi (0.5 km) upstream of Highway 155, 3.1 mi (5.0 km) east of Ciales, and 1.0 mi (1.6 km) northwest of Morovis plaza. DRAINAGE AREA mi 2 (km 2 ) 2.72 (7.04) 3/30/95 6/01/95 0930 0815 STREAM FLOWS ft'/S (mVs) 2.10 (0.059) 2.83 (0.080) 50038750 50038895 Quebrada Grande de Morovis on Highway 634 near Morovis, PR Rio Indio on Highway 22 at Rio Abajo, PR 50040500 Rio de La Plata on Highway 738 near Cayey, PR 50040590 Rio Guavate on Highway 52 near Cayey, PR 50040700 50041010 50041020 Quebrada Beatriz on Highway 1 near Cayey, PR Rio de La Plata on Highway 171 near Cayey, PR Quebrada Santo Domingo at Cayey, PR Lat 18°21'33", long 66?24'39", 7.41 3/30/95 1015 0.27 Hydrologic Unit 21010002, at (19.2) (0.008) barrio Franquez, 0.8 mi (1.3 6/01/95 0930 1.63 km) upstream from Rio Morovis, (0.046) 4.1 mi (6.6 km) northeast from Ciales, and 2.2 mi (3.5 km) north of Morovis plaza. Lat 18°25'47", long 66°22'55", Indeter- 3/30/95 1215 6.79 Hydrologic Unit 21010002, at minate (0.192) barrio Rio Abajo on Highway 22, 6/01/95 1200 15.4 1.2 mi (1.9 km) south from (0.436) Highway 2, 7.2 mi (12 km) east of Manati, and 3.6 mi (5.8 km) northwest of Vega Alta plaza. Rio de La Plata basin Lat 18°07'25", long 66 0 07'56», 13.4 3/29/95 1400 13.7 Hydrologic Unit 21010005, at (34.7) (0.388) barrio Monte Llano on Highway 5/31/95 1245 11.1 738, 100 ft (30 m) upstream (0.314) from pumping station intake, 0.5 mi (0.8 km) southwest of Central Cayey, and 2.6 mi (4.2 km) northeast of Cayey plaza. Lat 18°07'51", long 66°07'04", 6.62 3/30/95 1145 2.32 Hydrologic Unit 21010005, at (17.1) (0.066) barrio Vegas, 1.2 mi (1.9 km) 6/01/95 0745 4.38 upstream from Rio de La Plata, (0.124) 2.9 mi (4.7 km) southwest from Cerro Las Pinas, and 4.3 mi (6.9 km) southeast of Cidra plaza. Lat 18°08'30", long 66°06'57", 3.42 3/29/95 1545 0.98 Hydrologic Unit 21010005, at (8.86) (0.028) barrio Beatriz on Highway 1, 8/09/95 1030 1.74 2.2 mi (3.5 km) upstream from (0.049) Rio de La Plata, 2.5 mi (4.0 km) southwest from Cerro Las Pinas, and 3.9 mi (6.3 km) southeast of Cidra plaza. Lat 18°08'07", long 66°10'08", 34.2 3/30/95 0845 6.25 Hydrologic Unit 21010005, at (88.6) (0.177) barrio Rincon on Highway 171, 6/01/95 1030 3.01 0.8 mi (1.3 km) northwest from (0.085) Cerro La Guasima, 250 ft (76 m) upstream from Quebrada Santo Domingo, and 3.0 mi (4.8 km) southwest of Cidra plaza. Lat 18°06'22" / long 66°09'55", 0.84 3/29/95 1215 0.13 Hydrologic Unit 21010005, at (2.18) (0.004) Cayey on Highway 1, 3.2 mi 5/31/95 1100 0.24 (5.1 km) northeast from Cerro (0.007) Planada, 1.7 mi (2.7 km) north- east from Monte El Gato, and 0.5 mi (0.8 km) southeast of Cayey plaza. 50042800 Rio Maton on Highway 14 at Maton Abajo, PR Lat 18°08'29", long 66°12'40", Hydrologic Unit 21010005, at barrio Maton Abajo on Highway 14, 250 ft (76 m) upstream of Rio de La Plata, 1.0 mi (1.6 km) south of Cerro Plana, and 4.1 mi (6.6 km) southwest of Cidra plaza. 6.63 (17.2) 3/29/95 5/31/95 1115 1015 0.93 (0.026) 1.89 (0.054) 425 STATION NUMBER 50043010 STATION NAME Quebrada Honda at mouth at Proyecto La Plata, PR 50043197 50043450 50043475 Rio Usabon on Highway 162 near Barrancjuitas, PR Rio Aibonito at Llanos near Aibonito, PR Rio BarranQuitas at Barrancjuitas, PR DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued LOCATION AND BASIN DRAINAGE AREA mi' (km') Rio de la Plata basin Lat 18°09'36", long 66°13'48", 2.66 Hydrologic Unit 21010005, at (6.89) barrio Plata, 100 ft (30 m) upstream from Rio de La Plata, 1.3 mi (2.1 km) northwest from Cerro Plana, 0.9 mi (1.4 km) from Cerro Amoldadero, and 4.7 mi (7.6 km) southwest of Cidra plaza. Lat 18°09'41», long 66°18'26", 8.56 Hydrologic Unit 21010005, at (22.2) barrio Helechal on Highway 162, 2.1 mi (3.4 km) northeast from Cerro Pulguillas, 3.0 mi (4.8 km) northwest from Aibonito, and 1.8 mi (2.9 km) south of BarranQuitas plaza. Lat 18°09'19», long 66°17'07", 6.48 Hydrologic Unit 21010005, at (16.8) barrio Llanos, 2.1 mi (3.4 km) southeast from Canon de San Cristobal, 2.7 mi (4.3 km) southeast from Barrancjuitas, and 1.5 mi (2.4 km) northwest of Aibonito plaza. Lat 18°11'19'', long 66°18'15", 3.75 Hydrologic Unit 21010005, at (9.71) Barrancjuitas, 0.1 mi (0.2 km) upstream from Highway 156, 2.1 mi (3.4 km) southeast from Cerro La Torrecilla, 1.6 mi (2.6 km) northwest from Canon de San Cristobal, and 0.2 mi (0.3 km) east of Barrranguitas. DATE 3/29/95 5/31/95 0900 0930 3/29/95 5/26/95 3/29/95 5/26/95 3/29/95 5/26/95 1230 0930 1145 1030 1330 0845 STREAM FLOWS ftVs (mVs) 0.34 (0.010) 0.76 (0.022) 0.64 (0.018) 1.59 (0.045) 1.97 (0.056) 2.95 (0.084) 0.95 (0.027) 1.77 (0.0.50) 50043575 Rio Hondo on Highway 776 at Rio Hondo, PR 50043850 50043950 50043998 Rio Arroyata on Highway 171 at Cidra, PR Rio Arroyata on Highway 775 near Cidra, PR Rio Arroyata at mouth near Comerio, PR 50044300 Rio Cuesta Arriba on Highway 816 at Nuevo, PR Lat 18°13'18", long 66°15'07" 9.07 3/29/95 1015 2.76 Hydrologic Unit 21010005, at (23.5) (0.078) barrio Rio Hondo on Highway 5/26/95 0745 5.51 776, 0.4 mi (0.6 km) north of (0.156) Escuela Segunda Unidad de Rio Hondo, 4.3 mi (6.9 km) north- east of Barranquitas, and 4.4 mi (7.1 km) northeast of Canon de San Cristobal. Lat 18°10'16", long 66°09'44», 0.70 3/30/95 0800 ——- Hydrologic Unit 21010005, at (1.81) barrio Sud on Highway 171, 0.8 8/09/95 0930 0.05 mi (1.3 km) southwest from Lago (0.001) Cidra, 2.8 mi (4.5 km) northeast from Cerro Gordo, and 0.5 mi (0.8 km) south of Cidra plaza. Lat 18°12'04", long 66oi2'34«, 9.42 3/30/95 1015 0.59 Hydrologic Unit 21010004, at (24.4) (0.017) barrio Vega Redonda on Highway 8/09/95 0900 1.24 775, 1.5 mi (2.4 km) of Cerro (0.035) Almirante, 1.6 mi (2.6 km) north of Cerro Viento Caliente, and 1.8 mi (2.9 km) southeast of Comerio plaza. Lat 18°14'26", long 66°12'32», 16.2 3/30/95 1415 1.68 Hydrologic Unit 21010005, at (42.0) (0.048) barrio Naranjo on Highway 156, 8/09/95 0800 1.81 150 ft (46 m) upstream from Rio (0.051) de La Plata, 1.6 mi (2.6 km) southwest from Cerro La Tiza, 1.8 mi (2.9 km) northeast of Comerio plaza. Lat 18°17'56", long 66°12 / 24", 5.51 3/30/95 1515 1.48 Hydrologic Unit 21010005, at (14.3) (0.042) barrio Nuevo on Highway 816, 5/30/95 0845 1.72 0.3 mi (0.5 km) upstream from (0.049) Rio de La Plata, 1.3 mi (2.1 km) northeast of Cerro Avispa, and 2.6 mi (4.2 km) southeast of Naranjito plaza. 426 STATION NUMBER 50044775 50044975 50045100 STATION NAME Rio Guadiana above sewage plant at Naranjito, PR Rio Canas at Achiote near Naranjito, PR Quebrada Cruz on Highway 824 near Toa Alta, PR 50045400 Rio Bucarabones near Toa Alta, PR 50045800 Rio Lajas at Toa Alta, PR 50047475 50047520 Quebrada Cerro Gordo at La Aldea at Bayamon, PR Rio Hondo II at Sabana Seca, PR 50047598 50047600 Quebrada Vicente at mouth, PR Rio Bayamon near Aguas Buenas, PR DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations—Continued LOCATION AND BASIN DRAINAGE AREA mi* (km*) Rio de La Plata basin Lat 18°18'08", long 66°14'18", 5.42 Hydrologic Unit 21010005, at (14.2) barrio Guadiana, 0.2 mi (0.3 km) upstream from Quebrada Anones, 1.7 mi (2.7 km) from Cerro Avispa, and 0.6 mi (1.0 km) east of Naranjito plaza. Lat 18°19'21", long 66°15'14", 3.14 Hydrologic Unit 21010005, at (8.13) barrio Achiote, 1.7 mi (2.7 km) upstream from Lago La Plata, 1.5 mi (2.4 km) northwest from Naranjito plaza, and 4.5 mi (7.2 km) southeast of Corozal plaza. Lat 18°21'26", long 66°14'50", 2.13 Hydrologic Unit 21010005, at (5.52) barrio Quebrada Cruz on High- way 824, 0.3 mi (0.5 km) up- stream from Rio de La Plata, 1.1 mi (1.8 km) northwest from Lago La Plata spillway, and 3.7 mi (6.0 km) north of Naranjito plaza. Lat 18°21'49", long 66°12'54", 1.23 Hydrologic unit 21010005, at (3.19) barrio Ortiz, 4.7 mi (7.6 km) northeast from Naranjito, 3.1 mi (5.0 km) northwest from Cerro Gordo Arriba, and 2.8 mi (4.5 km) southeast of Toa Alta plaza. Lat 18°23'39", long 66°15'16", 8.60 Hydrologic Unit 21010005, at (22.3) Toa Alta on Highway 165, 0.2 mi (0.3 km) upstream from Rio de La Plata, 1.8 mi (2.9 km) downstream of Quebrada Arenas, and 0.3 mi (0.5 km) northwest of Toa Alta plaza. Rio Bayamon basin Lat 18°22'38", long 66°10'31", 2.15 Hydrologic Unit 21010005, at (5.57) barrio Cerro Gordo on Highway 840, 1.2 mi (1.9 km) upstream of Rio Hondo, 4.9 mi (7.9 km), southeast from Toa Alta, and 2.0 mi (3.2 km) southwest of Bayamon plaza. Lat 18°25'24 11 , long 66°11'07" 2.59 Hydrologic Unit 21010005, at (6.71) barrio Sabana Seca, 1.2 mi (1.9 km) northwest from Puerto Rico National Cemetery, 4.7 mi (7.6 km) northeast of Toa Alta, and 2.5 mi (4.0 km) northwest of Bayamon plaza. Lat 18°14'36", long 66°08'41', 2.21 Hydrologic Unit 21010005, at (5.72) barrio Bayamoncito off Highway 156, 100 ft (30 m) upstream from Rio Bayamon, 1.2 mi (1.9 km) northeast from Cerro Santa Barbara, and 4.6 mi (7.4 km) northeast of Cidra plaza. Lat 18°14'39", long 66°08'39", 10.2 Hydrologic Unit 21010005, at (26.4) barrio Bayamoncito on Highway 156, 1.3 mi (2.1 km) southwest from Cerro Santa Barbara, 2.7 mi (4.3 km) east from Cerro La Tiza, and 4.7 mi (7.6 km) northeast of Cidra plaza. DATE 3/27/95 6/02/95 3/27/95 6/02/95 3/27/95 5/30/95 1245 0730 1030 0630 0930 1400 3/27/95 5/30/95 3/27/95 6/02/95 0845 1500 0745 1100 3/27/95 5/25/95 3/27/95 5/25/95 3/28/95 5/26/95 3/28/95 5/26/95 1145 0900 1045 0815 0830 0645 0900 0730 STREAM FLOWS ftVs (mVs) 2.81 (0.080) 4.73 (0.134) 0.99 (0.028) 3.26 (0.092) 0.59 (0.017) 1.17 (0.033) 0.81 (0.023) 0.75 (0.021) 1.45 (0.041) 1.60 (0.045) 0.75 (0.021) 0.90 (0.025) 0.45 (0.013) 0.41 (0.012) 0.63 (0.018) 0.96 (0.027) 12.1 (0.343) 14.0 (0.396) 427 STATION STATION NUMBER NAME 50047750 Quebrada Grande near Aguas Buenas, PR DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued LOCATION AND BASIN Rio Bayamon basin Lat 18°16'02", long 66°08'33", Hydrologic Unit 21010005, at barrio Juan Asencio, 0.2 mi (0.3 km) upstream from Rio Bayamon, 0.7 mi (1.1 km) southeast from Cerro Mula, 1.0 mi (1.6 km) southwest from Cerro del Chicharo, and 2.6 mi (4.2 km) northwest of Aguas Buenas plaza. DRAINAGE AREA mi 2 (km») 4.08 (10.6) 3/28/95 5/25/95 1045 1315 STREAM FLOWS ftVs (ma /s) 1.39 (0.039) 1.15 (0.032) 50047810 Quebrada Sonadora at Sonadora, PR 50047840 50047860 50047870 Quebrada Santa Olaya on Highway 174 near Bayamon, PR Rio Minillas on Highway 174 near Minillas, PR Rio Bayamon near Minillas, PR 50047895 Rio Guaynabo at Highway 836 near Guaynabo, PR Lat 18°17'47», long 66°07'58", 2.60 3/28/95 1215 0.11 Hydrologic Unit 21010005, at (6.73) (0.003) barrio Sonadora, 0.7 mi (1.1 5/26/95 0845 0.11 km) upstream from Rio Bayamon, (0.003) 1.4 mi (2.2 km) northeast from 8/08/95 1145 1.10 Cerro La Pena, 1.2 mi (1.9 km) (0.031) north from Cerro del Chicharo, and 3.2 mi (5.1 km) northwest of Aguas Buenas plaza. Lat 18°19'46", long 66°08'35", 4.10 3/27/95 1545 1.45 Hydrologic Unit 21010005, at (10.6) (0.041) barrio Guaraguao Abajo on 5/25/95 1215 1.05 Highway 174, 0.1 mi (0.2 km) (0.030) upstream from Rio Bayamon, 1.2 mi (1.9 km) northeast of Cerro de Vergara, and 2.9 mi (4.7 km) southwest of Guaynabo plaza. Lat 18°21'34», long 66°08'38», 4.80 3/27/95 1400 2.56 Hydrologic Unit 21010005, at (12.4) (0.072) barrio Minillas on Highway 5/25/95 1045 1.26 174, 0.1 mi (0.2 km) upstream (0.036) from Rio Bayamon, 2.1 mi (3.4 km) northeast from Cerro Gordo Arriba, and 2.9 mi (4.7 km) southeast of Bayamon plaza. Lat 18°21'53", long 66°08'30", 40.8 3/27/95 1315 8.91 Hydrologic Unit 21010005, at (106) (0.252) barrio Minillas, 1.3 mi (2.1 5/25/95 1015 5.66 km) upstream from Rio Guaynabo, (0.160) 2.4 mi (3.9 km) northeast from Cerro Gordo Arriba, and 2.6 mi (4.2 km) southeast of Bayamon plaza. Lat 18°20'05", long 66°06'10", 8.44 3/28/95 1415 4.02 Hydrologic Unit 21010005, at (21.9) (0.114) barrio Mamey on Highway 836, 5/26/95 1045 3.05 0.6 mi (1.0 km) southwest of (0.086) Cerro Magueyes, 3.7 mi (6.0 km) from Cerro Marguesa, and 1.8 mi (2.9 km) southeast of Guaynabo plaza. 50047953 Rio Guaynabo below Guaynabo, PR 50047970 Quebrada Frailes on Highway 169 at Guaynabo, PR Lat 18°22'00'1 , long 66°07'09", 12.8 3/28/95 1600 7.31 Hydrologic Unit 21010005, at (33.2) (0.207) barrio Santa Rosa, 0.4 mi (0.6 5/26/95 1200 5.65 km) upstream from Quebrada (0.160) Frailes, 3.1 mi (5.0 km) north- west from Cerro Magueyes, and 0.7 mi (1.1 km) northwest from Guaynabo plaza. Lat 18°22'07», long 66 0 06'42 M , 3.48 3/28/95' 1515 3.34 Hydrologic Unit 21010005, at (9.01) (0.094) Guaynabo on Highway 169, 1.9 5/26/95 1130 2.51 mi (3.1 km) northwest from (0.071) Cerro Magueyes, 1.2 mi (1.9 km) upstream from Rio Guaynabo, and 0.6 mi (1.0 km) north from Guaynabo plaza. 428 DISCHARGE AT PARTIAL-RECORD STATIONS STATION NUMBER 50048750 STATION NAME Quebrada Las Curias Tributary near Caimito, PR 50048760 Quebrada Los Guanos near Rio Piedras, PR 50146700 Rio Culebrinas at Perchas No. 1, PR 50147000 Rio Culebrinas at San Sebastian, PR 50147200 Rio Guatemala at San Sebastian, PR 50147400 Rio Sonador near San Sebastian, PR 50147796 Quebrada Los Morones near Moca, PR Low-flow partial-record stations--Continued LOCATION AND BASIN DRAINAGE AREA mi* (km*) Rio Piedras basin Lat 18°20'19", long 66°03'33", 1.73 Hydrologic Unit 21010005, at (4.48) barrio Caimito, 0.7 mi (1.1 km) upstream from Quebrada Las Curias, 0.7 mi (1.1 km) south- west from Aljibe Las Curias, and 2.9 mi (4.7 km) northwest of Lago Carraizo spillway. Lat 18°21'24", long 66°03'20", 0.76 Hydrologic Unit 21010005, at (1.97) barrio Cupey, 0.8 mi (1.3 km) upstream from Rio Piedras, 3.2 mi (5.1 km) northwest from Lago Carraizo spillway, and 3.1 mi (5.0 km) west of Trujillo Alto plaza. Rio Culebrinas basin Lat 18°18'09", long 66°56'49", 6.82 Hydrologic Unit 21010003, at (17.7) barrio Perchas No. 1, 1.4 mi (2.2 km) upstream of Quebrada Lajas, 1.2 mi (1.9 km) down- stream from Quebrada Grande, and 3.8 mi (6.1 km) southeast of San Sebastian plaza. Lat 18°20'08», long 66°59'46", 16.7 Hydrologic Unit 21010003, at (43.2) San Sebastian on Highway 109, 0.9 mi (1.4 km) upstream from Rio Guatemala, 200 ft (61 m) upstream from sewage plant discharge point, and 0.4 mi (0.6 km) southwest from San Sebastian plaza. Lat 18°20'42', long 67°00'00", 10.3 Hydrologic Unit 21010003, at (26.7) San Sebastian on Highway 111, 1.2 mi (1.9 km) upstream from Rio Culebrinas, 0.9 mi (1.4 km) southeast of Central La Plata, and 0.7 mi (1.1 km) northeast of San Sebastian plaza. Lat 18°18'49", long 67°00'29», 6.09 Hydrologic Unit 21010003, at (15.8) barrio Culebrinas on Highway 109, 1.3 mi (2.1 km) northeast from Cerro Yaitini, 2.1 mi (3.4 km) northeast from Cerro Cascajillo, and 2.0 mi (3.2 km) southwest from San Sebastian plaza. Lat 18°21'24", long 67°05'23", 7.18 Hydrologic Unit 21010003, at (18.6) barrio Cerro Gordo, 0.6 mi (1.0 km) upstream from Rio Culebrinas, 3.6 mi (5.8 km) northwest from Cerro Pichon, 2.8 mi (4.5 km) northeast from Cerro Pelao, and 5.1 mi (8.2 km) northwest of Cental La Plata. DATE 3/31/95 5/30/95 3/31/95 5/30/95 1145 1230 1245 1200 4/05/95 6/13/95 4/05/95 6/13/95 1045 1130 0900 1030 4/05/95 6/13/95 7/27/95 4/05/95 6/13/95 0800 0800 1145 0945 0930 4/05/95 6/13/95 7/27/95 1200 1300 1030 STREAM FLOWS ftVs (mVs) 1.19 (0.034) 0.73 (0.021) 0.74 (0.021) 0.50 (0.014) 4.54 (0.128) 32.3 (0.915) 5.66 (0.160) 106 (3.002) 1.18 (0.033) 93.6 (2.651) 9.33 (0.264) 8.30 (0.235) 49.1 (1.390) 9.36 (0.265) 26.2 (0.742) 16.2 (0.459) 50147997 50148500 Quebrada Grande near Moca, PR Rio Canas near Aguada, PR Lat 18°22'50", long 67°06'49", 4.72 4/05/95 1330 1.00 Hydroloigc unit 21010003, at (12.2) (0.028) barrio Cruz, 0.2 mi (0.3 km) 6/13/95 1400 19.2 upstream from Rio Culebrinas, (0.538) 2.6 mi (4.2 km) southwest from Monte El Ojo, and 1.0 mi (1.6 km) south of Moca plaza. Lat 18°22'19", long 67°09'06", 5.14 6/13/95 1445 7.42 Hydrologic Unit 21010003, at (13.3) (0.210) barrio Naranjo on Highway 417, 7/27/95 0830 5.41 2.4 mi (3.9 km) northwest from (0.153) Cerro Gordo, 4.5 mi (7.2 km) northeast of Cerro Canta Gallo, and 6.1 mi (9.8 km) north of Anasco plaza. 429 430 ANALYSES OF SAMPLES COLLECTED AT HATER-QUALITY PARTIAL-RECORD STATION Hater-quality partial-record stations are particcular sites where chemical-quality, biological and or sediment data are collected systematically over a period of years for use in hydrological analysis. The data are collected usually less than quarterly. HATER-QUALITY DATA, HATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 DATE- 50010720 NOV 1994 23.. . MAR 1995 10... JUL 14.. . SPE- CIFIC SAM- CON- PLING DUCT- TIME DEPTH ANCE (FEET) (US/CM) LAGO GUAJATACA NO. 3 0815 0740 0805 1.00 1.00 1.00 336 397 211 PH HATER TRANS- WHOLE PAR- FIELD TEMPER- ENCY (STAND- ATURE (SECCHI ARD HATER DISK) UNITS) (DEG C) (IN) RIO GUAJATACA BASIN NR MOUTH NR QUEBRADILLAS , PR 7.6 7.8 7.6 27.0 26.0 29.5 67.0 66.0 63.0 OXYGEN, COLI- DIS- FORM, SOLVED FECAL, OXYGEN, (PER- 0.7 DIS- CENT UM-MF SOLVED SATUR- (COLS./ (MG/L) ATION) 100 ML) (LAT 18°22'05"N LONG 066°54 6 7 11 .3 .1 .1 80 89 149 12 8 2 STREP- TOCOCCI FECAL, KF AGAR (COLS. PER 100 ML) '36"H) 48 24 92 RIO GRANDE DE ARBCIBO BASIN 50025110 NOV 1994 21.. . MAR 1995 08.. . JUL 10.. . 50039900 NOV 1994 17... MAR 1995 03.. . JUL 07... 50044400 MAR 1995 07.. . AUG 01.. . SEP 21.. . 30.. . 50047537 NOV 1994 28. . . MAR 1995 02.. . MAY 26.. . JUL 11.. . 50057500 NOV 1994 18.. . MAR 1995 01.. . JUL 06.. . LAGO 0810 0900 1000 LAGO 0820 0820 0930 LAGO 0830 0745 0845 1005 LAGO 1015 0845 1110 0820 LAGO 0925 0915 1250 DOS BOCAS 1.00 1.00 1.00 CARITE NO. 1.00 1.00 1.00 NO. 3 339 364 315 3 ON 169 200 135 AT WEST BRANCH NR UTUADO,PR 6.8 7.8 7.4 RIO 27.0 26.0 28.0 20.4 15.6 17.2 (LAT 4 7 4 18°19' .9 .5 .0 15 "N LONG 61 92 51 066°40 360 220 650 '11"H) 120 170 200 DE LA PLATA BASIN RIO DE LA PLATA NR 6.8 7.1 7.4 25.0 23.5 29.0 CAYEY, PR 50.4 24.2 33.5 (LAT 7 6 7 18°05' .3 .7 .9 LA PLATA NO. 5 MR MOUTH NR NARANJITO, PR (LAT 18°19'33" 1.00 1.00 1.00 1.00 443 323 333 351 7.2 7.8 7.8 7.6 RIO DE CIDRA NR RIO BAYAMON 1.00 1.00 1.00 1.00 LOIZA NO. 4 1.00 1.00 1.00 349 348 343 302 6.9 6.8 6.8 7.6 RIO 24.5 27.5 27.0 28.0 DE BAYAMON MOUTH (LAT 26.0 24.5 27.0 29.0 7.20 8.60 10.8 7.20 BASIN 18°11'02 30.0 24.0 11.0 19.0 3 6 6 6 .5 .7 .7 .8 04 "N LONG 92 82 109 066°06 K12 26 K10 N LONG 066°12'28 42 86 84 86 970 570 290 680 '03"H) K4 470 K18 "H) K1600 810 K18 360 "N LONG 066°08'06"H) 5 5 6 7 .3 .6 .0 .6 68 69 75 103 K6 82 K<1 150 K7 240 K<1 38 GRANDS DE LOIZA BASIN NR MOUTH NR CAGUAS, PR 364 319 455 6.5 6.0 7.3 28.0 25.0 30.5 (LAT 18e 16'51"N LONG 21.6 13.6 12.1 4 3 4 .1 .8 .9 066°00'35 52 46 65 "H) 230 5200 2400 K14 4000 45 K = non-ideal count 431 ANALYSES OF SAMPLES COLLECTED AT WATER-QUALITY PARTIAL-RECORD STATION WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 ALKA- RESIDUE NITRO- CHLOR-A CHLOR-B LINITY TOTAL NITRO- GEN, AM- PHYTO- PHYTO- WAT WH AT 105 GEN, MONIA + NITRO- PHOS- PLANK- PLANK- PLANK- TOT PET DEG. C, ORGANIC ORGANIC GEN, PHORUS TON TON TON FIELD SUS- TOTAL TOTAL TOTAL TOTAL CHROMO CHROMO BIOMASS DATE MG/L AS FENDED (HG/L (MG/L (HG/L (MG/L FLUOROM FLUOROM ASH WT CAC03 (MG/L) AS N) AS N) AS N) AS P) (UG/L) (UG/L) (MG/L) 50010720 NOV 1994 23... MAR 1995 10.. . JUL 14.. . 50025110 NOV 1994 21.. . MAR 1995 08.. . JUL 10.. . 50039900 NOV 1994 17... MAR 1995 03.. . JUL 07.. . 50044400 MAR 1995 07... AUG 01... SEP 21... 30.. . 50047537 NOV 1994 28.. . MAR 1995 02.. . JUL 11.. . 50057500 MOV 1994 18.. . MAR 1995 01... JUL 06.. . LAGO 120 140 79 LAGO 93 91 97 LAGO 39 36 38 LAGO 110 120 94 110 LAGO 61 69 79 LAGO 82 64 150 GUAJATACA <1 1 7 DOS BOCAS 7 12 3 CARITE NO. 2 4 7 RIO GUAJATACA BASIN- -Continued NO. 3 NR MOUTH NR QUEBRADILLAS, PR (LAT 18°22'05"N LONG 066°54 0.40 0.40 0.40 0.040 10.0 1.50 230 0.40 0.40 0.40 0.030 8.20 0.200 240 0.30 0.30 0.30 0.020 9.40 2.30 370 RIO QRANDE DE ARECIBO BASIN- -Continued NO. 3 AT WEST BRANCH NR UTUADO, PR (LAT 18° 19' 15 "N LONG 066° 40 0.30 0.30 0.30 <0.010 19.0 2.00 250 0.60 0.60 0.60 0.050 31.0 2.30 300 0.50 0.50 0.50 0.030 5.70 0.300 270 RIO DE LA PLATA BASIN- -Continued 3 ON RIO DE LA PLATA NR CAYEY, PR (LAT 18° 05' 04 "N LONG 066° 06 0.20 0.20 0.20 0.030 6.60 1.60 250 0.30 0.30 0.30 <0.010 7.70 0.500 240 0.20 0.20 0.20 <0.010 11.0 1.80 260 LA PLATA NO. 5 NR MOUTH NR NARANJITO, PR (LAT 18°19'33"N LONG 066°12'28 12 9 11 15 0.90 0.90 0.90 0.150 2.40 0.100 260 0.30 0.30 0.30 0.020 9.40 2.30 370 0.60 0.60 0.60 0.300 8.10 <0.100 310 0.50 0.50 0.50 0.200 7.80 0.700 590 RIO DE BAYAMON BASIN- -Continued PLANK- TON BIOMASS DRY WT (MG/L) '36"W) 240 250 380 '11"W) 250 300 280 '03"W) 250 240 270 "W) 270 380 310 600 DE CIDRA NR RIO BAYAMON MOUTH (LAT 18° 11' 02 "N LONG 066°08'06"W) 4 7 9 LOIZA NO. 4 6 54 6 0.60 0.60 0.60 <0.010 2.30 0.200 240 0.40 0.40 0.40 0.010 6.60 0.500 350 0.30 0.30 0.30 <0.010 8.60 0.900 310 RIO GRANDS DE LOIZA BASIN- -Continued NR MOUTH NR CAGUAS, PR (LAT 18°16'51"N LONG 066°00'35"W) 1.6 1.6 1.6 0.310 12.0 1.90 300 1.5 1.5 1.5 0.380 1.20 <0.100 1190 1.9 1.9 1.9 0.420 40.0 5.40 260 250 360 320 310 1220 270 432 WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MISCELLANEOUS STATION ANALYSES DATE TIME 50010790 NOV 1994 23... 0845 23... 0840 MAR 1995 10... 0815 10... 0810 JUL 14... 0855 14... 0840 50020050 NOV 1994 22... 1040 22... 1030 MAR 1995 09... 1135 09... 1130 JUL 13... 1145 13... 1135 50027090 NOV 1994 21... 0855 21... 0845 MAR 1995 08... 0935 08... 0925 JUL 10... 1050 10... 1040 50039950 NOV 1994 17... 0850 17... 0840 MAR 1995 03... 0800 03... 0755 JUL 07... 1005 07... 0955 50044950 MAR 1995 07... 0900 07... 0855 SEP 30... 0815 30... 0805 50047549 NOV 1994 18... 0945 18... 0940 MAR 1995 02... 0825 02... 0820 MAY 26... 1000 26... 0950 JUL 11... 0900 11... 0845 50058800 NOV 1994 18... 1000 18... 0955 MAR 1995 01... 0845 01... 0830 JUL 06... 1030 06... 1040 K = non- ideal count SAM- PLING DEPTH (FEET) LAGO 1.00 79.0 1.00 43.0 1.00 52.0 LAGO 1.00 74.0 1.00 66.0 1.00 59.0 LAGO 1.00 72.0 1.00 75.0 1.00 75.0 LAGO 1.00 59.0 1.00 56.0 1.00 39.0 LAGO 1.00 30.0 1.00 88.6 LAGO 1.00 30.0 1.00 30.0 1.00 36.0 1.00 33.0 LAGO 1.00 23.0 1.00 30.0 1.00 16.0 SPE- CIFIC CON- DUCT- ANCE (US/CM) GUAJATACA 332 383 385 409 227 344 GARZAS NO, 227 283 255 244 177 196 DOS BOCAS 362 326 349 324 275 260 CARITE NO. 170 260 200 187 133 149 PH OXYGEN, COLI- WATER TRANS- DIS- FORM, WHOLE PAR- SOLVED FECAL, FIELD TEMPER- ENCY OXYGEN, (PER- 0.7 (STAND- ATTIRE (SECCHI DIS- CENT UM-MF ARD WATER DISK) SOLVED SATtTR- (COLS. / UNITS) (DEG C) (IN) (MG/L) ATION) 100 ML) RIO GUAJATACA BASIN- -Continued STREP- TOCOCCI FECAL, KF AGAR (COLS. PER 100 ML) NO.l NR DAM NR QUEBRADILLAS , PR (LAT 18° 23' 56"N LONG 066° 55' 8.2 27.0 108 8.0 101 K2 6.8 24.5 -- 0.2 2 7.6 26.0 92.0 6.4 80 K2 7.0 24.5 -- 0.4 4 7.4 29.0 78.0 10.4 138 K2 7.0 24.5 -- 0.6 7 RIO GRANDE DE ARECIBO BASIN--Continued .1 NR DAM NR ADJUNTAS, PR (LAT 18° 08' 21 "N LONG 066° 6.9 23.5 30.0 7.1 91 K13 6.5 21.5 -- 0.2 2 7.4 22.0 64.8 7.4 90 68 6.8 20.5 -- 2.6 35 6.8 20.5 58.0 7.2 92 K8 6.4 19.2 -- 0.7 8 NO.l NR DAM NR UTUADO,PR (LAT 18° 20' 09"N LONG 066° 7.7 27.0 96.0 7.6 95 K9 6.7 26.5 -- 0.2 2 8.2 26.0 38.4 8.3 102 K13 6.7 24.0 -- 0.8 9 8.9 29.0 49.3 9.2 121 K130 6.9 26.0 -- 0.6 7 RIO DE LA PLATA BASIN- -Continued K2 -- K2 -- 20 -- 44' 35"W) KB -- K4 -- K4 -- 40' 04 "W) K4 -- 570 -- K2 -- HARD- NESS TOTAL (MG/L AS CACO3 ) 23 "W) 130 150 140 150 94 150 64 68 68 64 65 63 95 95 100 89 96 87 1 NR DAM NR CAYEY, P.R. (LAT 18° 04' 39"N LONG 066° 06' 19"W) 6.9 25.0 39.6 10.3 129 K9 6.3 23.0 -- 0.2 80 7.1 23.5 49.8 7.2 88 K13 6.3 22.5 -- 2.1 25 8.3 28.0 42.5 7.6 103 K5 6.8 23.0 -- 0.6 7 K4 -- 570 -- K7 -- LA PLATA NO. 3 NR DAM NR NARANJITO, PR (LAT 18° 20' 18 "N LONG 066° 14' 01' 424 403 274 189 6.9 25.5 9.60 3.6 44 820 6.6 23.5 -- 0.4 5 7.6 28.0 15.6 9.2 116 290 6.6 24.5 -- 2.3 29 RIO DE BAYAMON BASIN--Continued 320 -- K18 -- 30 43 31 27 32 35 •W) 120 110 84 76 DE CIDRA NR DAM (LAT 18° 11' 52"N LONG 066° 08' 24"W) 341 340 348 312 324 368 290 322 LOIZA NO. 328 336 407 351 318 318 6.9 26.0 34.8 6.1 78 48 6.4 25.0 -- 0.2 3 7.1 24.5 36.0 6.5 81 K31 6.4 22.5 -- 1.8 22 7.1 27.5 16.0 7.4 93 97 6.5 24.1 -- 0.1 1 7.5 29.0 28.0 6.4 87 7 6.8 23.5 -- 0.7 9 RIO GRANDE DE LOIZA BASIN- -Continued 7 NR DAM NR TRUJILLO ALTO, PR (LAT 18° 19' 29 "N LONG 7.4 28.0 28.8 10.0 127 200 6.5 26.5 -- 0.3 3 7.0 25.5 6.00 2.5 30 370 6.7 23.5 -- 0.6 7 7.3 30.5 18.3 5.0 67 42 7.0 30.0 -- 1.3 17 K6 -- K20 -- 29 -- 4 -- 81 75 77 61 75 100 78 82 066° 00' 47"W) K24 -- 370 -- 52 -- 76 77 87 51 83 83 ANALYSES OF SAMPLES COLLECTED AT WATER-QUALITY PARTIAL-RECORD STATION WATER-QUALITY DATA, WATER YEAR OCTOBER 1994 TO SEPTEMBER 1995 MISCELLANEOUS STATION ANALYSES 433 MAGNE- CALCIUM SIUM, SODIUM, DIS- DIS- DIS- SOLVED SOLVED SOLVED DATE 50010790 NOV 1994 23.. . 23.. . MAR 1995 10.. . 10.. . JUL 14.. . 14.. . 50020050 NOV 1994 22.. . 22.. . MAR 1995 09. .. 09.. . JUL 13.. . 13.. . 50027090 NOV 1994 21.. . 21.. . MAR 1995 08.. . 08.. . JUL 10. .. 10.. . 50039950 NOV 1994 17... 17.. . MAR 1995 03.. . 03. .. JUL 07. .. 07.. . 50044950 MAR 1995 07.. . 07. .. SEP 30. . . 30.. . 50047549 NOV 1994 28.. . 28... MAR 1995 02. .. 02. .. JUL 11. …