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Water Resources Data Puerto Rico and the U.S. Virgin Islands Water Year 2001 U.S. Department of the Interior U.S. Geological Survey Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and with other agencies Isla de Vieques Isla de Culebra St. Thomas Island St. Croix Island P U E R T O R I C O St. John Island U.S. VIRGIN ISLANDS CONVERSION FACTORS AND VERTICAL DATUM Multiply By To obtain Length inch (in.) 2.54x101 millimeter 2.54x10-2 meter foot (ft) 3.048x10-1 meter mile (mi) 1.609x100 kilometer Area acre 4.047x103 square meter 4.047x10-1 square hectometer 4.047x10-3 square kilometer square mile (mi2) 2.590x100 square kilometer Volume gallon (gal) 3.785x100 liter 3.785x100 cubic decimeter 3.785x10-3 cubic meter million gallons (Mgal) 3.785x103 cubic meter 3.785x10-3 cubic hectometer cubic foot (ft3) 2.832x101 cubic decimeter 2.832x10-2 cubic meter cubic-foot-per-second day [(ft3/s) d] 2.447x103 cubic meter 2.447x10-3 cubic hectometer acre-foot (acre-ft) 1.233x103 cubic meter 1.233x10-3 cubic hectometer 1.233x10-6 cubic kilometer Flow cubic foot per second (ft3/s) 2.832x101 liter per second 2.832x101 cubic decimeter per second 2.832x10-2 cubic meter per second gallon per minute (gal/min) 6.309x10-2 liter per second 6.309x10-2 cubic decimeter per second 6.309x10-5 cubic meter per second million gallons per day (Mgal/d) 4.381x101 cubic decimeter per second 4.381x10-2 cubic meter per second Mass ton (short) 9.072x10-1 megagram or metric ton Sea level: In this report “sea level” refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929)—a geodetic datum derived from a general adjustment for the first-order level nets of both the United States and Canada, formerly called Sea Level Datum of 1929. U.S. Departm ent o f the Interio r U.S. G eo lo g ical Survey W ater Reso urces Data Puerto Rico and the U.S. Virg in Islands W ater Y ear 2001 Pedro L. Díaz, Z aida Aq uino , Carlo s F ig uero a-Alam o , René G arcía, and Ana V. Sánchez W ater-Data Repo rt PR-01-1 Prepared in co o peratio n w ith the Co m m o nw ealth o f Puerto Rico , the G o vernm ent o f the U.S. Virg in Islands, and w ith o ther ag encies CALENDAR FOR WATER YEAR 2001 2000 JANUARY NOVEMBER DECEMBER S M T W T F S S M T W T F S 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 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 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 2001 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 OCTOBER 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 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 S M T W T F S S M T W T F S S M T W T F S APRIL MAY JUNE S M T W T F S S M T W T F S 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 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 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 JULY AUGUST SEPTEMBER S M T W T F S S M T W T F S 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 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 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 U.S. DEPARTMENT OF THE INTERIOR GALE A. NORTON, Secretary U.S. GEOLOGICAL SURVEY Charles G. Groat, Director For additional information on the water-resources investigation programs in Puerto Rico and the U.S. Virgin Islands write to: Chief, Caribbean District, Water Resources Division U.S. Geological Survey GSA Center, 651 Federal Drive Suite 400-15 Guaynabo, Puerto Rico 00965 Telephone: (787) 749-4346 2002 III PREFACE This annual hydrologic data report of Puerto Rico and the U.S. Virgin Islands is one of a series of annual reports that document hydrologic data gathered from the U.S. Geological Survey's surface- and ground-water data-collection networks in each state, Puerto Rico, the U.S. Virgin Islands, and the other Trust Territories. These records of streamflow, ground-water levels, and quality-of-water provide the hydrologic information needed by state, local, and Federal agencies, and the private sector for developing and managing our Nation's land and water resources. The report is the culmination of a concerted effort by dedicated personnel of the U.S. Geological Survey, Water Resources Division, who collected, compiled, analyzed, verified, and organized the data, and who typed, edited, and assembled the report. In addition to the authors, who had primary responsibility for assuring that the information contained herein is accurate, complete, and adheres to the U.S. Geological Survey policy and established guidelines, the following personnel contributed significantly to the collection, processing, and tabulations of the data: José M. Agis Rafael Peña-Cortéz George Arroyo Ronald T. Richards Ramòn Carrasquillo Carlos C. Rodríguez Gregory Cherry Julio A. Rodríguez Iris M. Concepción Miguel A. Rodríguez José A. Concepción Rafael M. Rodríguez Israel Cruz Manuel Rosario Teresa Dopazo José René Sánchez Angel G. Ferrer Luis Santiago-Rivera Wilfredo García Carlos Santos Hector Guardiola Luis Soler Evelyn S. Guevara Elliot M. Sosa Senén Guzmán-Ríos Angel Torres Felipe Hernández Heriberto Torres-Sierra Sandra Lagares James Torres Christian D. López Ricardo J. Vachier José Merced Ahmed Valencia Carlos Narvaez Luis Vega Nilo Peña Francisco Maldonado prepared the illustrations and Evelyn S. Guevara and Ruth I. Guzmán typed the text of the report and were mainly responsible for the assemble of the book using Automated Annual Report (AAR) Scripts for Surface-Water Discharge and Water-Quality Stations. This report was prepared in cooperation with agencies of the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and with other Federal agencies under the general supervision of Matthew C. Larsen, Caribbean District Chief, San Juan, Puerto Rico. V CONTENTS Page Preface ................................................................................................................................................................... iii List of surface-water and water-quality stations, in downstream order, for which records are published in this volume .......................................................................................................................... vii List of ground-water wells, by basin, for which records are published in this volume........................................ xii List of discontinued streamflow stations ...............................................................................................................xv Introduction..............................................................................................................................................................1 Cooperation..............................................................................................................................................................2 Summary of hydrologic conditions..........................................................................................................................3 Rainfall...............................................................................................................................................................3 Surface water......................................................................................................................................................3 Ground water......................................................................................................................................................5 Water quality......................................................................................................................................................8 Special networks and programs ...............................................................................................................................8 Explanation of records...........................................................................................................................................11 Station identification numbers .........................................................................................................................11 Downstream order system..........................................................................................................................11 Latitude-longitude system..........................................................................................................................11 Records of stage and water discharge..............................................................................................................17 Data collection and computation................................................................................................................17 Data presentation........................................................................................................................................18 Station manuscript................................................................................................................................19 Data table of daily mean values............................................................................................................20 Statistics of monthly mean data............................................................................................................20 Summary statistics................................................................................................................................20 Identifying estimated daily discharge.........................................................................................................22 Accuracy of the records..............................................................................................................................22 Records of surface-water quality .....................................................................................................................22 Classification of records.............................................................................................................................22 Arrangement of records..............................................................................................................................23 On-site measurements and sample collection ............................................................................................23 Water temperature......................................................................................................................................23 Sediment.....................................................................................................................................................24 Laboratory measurements ..........................................................................................................................24 Data presentation........................................................................................................................................24 Remark codes .............................................................................................................................................25 Records of ground-water levels .......................................................................................................................26 Data collection and computation................................................................................................................26 Data presentation........................................................................................................................................26 Records of ground-water quality......................................................................................................................27 Data collection and computation................................................................................................................27 Data presentation........................................................................................................................................27 Access to U.S. Geological Survey Water Data......................................................................................................28 Definition of terms.................................................................................................................................................29 Techniques of Water-Resources Investigations of the U.S. Geological Survey....................................................45 Surface- and quality-of-water records for Puerto Rico..........................................................................................49 Discharge at partial-record stations in Puerto Rico .............................................................................................461 Water-quality at partial-record stations in Puerto Rico and U.S. Virgin Islands.................................................471 Ground-water records for Puerto Rico.................................................................................................................481 Surface-water records for U.S. Virgin Islands.....................................................................................................595 Ground-water records for U.S. Virgin Islands ....................................................................................................605 Index ....................................................................................................................................................................615 VI ILLUSTRATIONS Page Figure 1. Graphs showing monthly-mean discharge of selected streams in Puerto Rico.....................................4 2. Graphs showing ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands ....6 3. Map showing location of maximum concentrations of fecal coliform bacteria at the water-quality sampling sites in Puerto Rico......................................................................................9 4. Map showing location of maximum concentrations of fecal streptococci bacteria at the water-quality sampling sites in Puerto Rico....................................................................................10 5. Map showing location of surface-water stations in Puerto Rico.........................................................12 6. Map showing location of water-quality stations in Puerto Rico .........................................................13 7. Map showing location of ground-water stations in Puerto Rico .........................................................14 8. Map showing location of surface-water stations in the U.S. Virgin Islands .......................................15 9. Map showing location of ground-water stations in the U.S. Virgin Islands .......................................16 10. Grid showing system for numbering wells and miscellaneous sites (latitude and longitude)............17 11. Map showing the Río Guajataca basin ...............................................................................................51 12. Map showing the Río Camuy basin....................................................................................................59 13. Map showing the Río Grande de Arecibo basin.................................................................................63 14. Map showing the Río Grande de Manatí basin ................................................................................145 15. Map showing the Río Cibuco basin..................................................................................................167 16. Map showing the Río de la Plata basin.............................................................................................175 17. Map showing the Río Hondo to Río Puerto Nuevo basins...............................................................193 18. Map showing the Río Grande de Loíza basin...................................................................................223 19. Map showing northeastern river basins -- Río Herrera to Río Antón Ruíz basins...........................299 20. Map showing southeastern river basins -- Río Humacao to Quebrada Aguas Verdes basins..........343 21. Map showing south coast river basins -- Río Salinas to Río Jacaguas basins..................................361 22. Map showing south coast river basins -- Río Inabón to Río Loco basins ........................................383 23. Map showing the Río Guanajibo basin.............................................................................................429 24. Map showing the Río Yagüez and Río Grande de Añasco basins ...................................................443 25. Map showing the Río Culebrinas basin............................................................................................453 26. Map showing location of low-flow partial-record stations in Mayagüez, Puerto Rico...................463 TABLES Page Table 1. Islandwide monthly rainfall for the water year 2001 and annual averages for the 30-year reference period, 1961-90......................................................................................................3 2. Highest ground-water level recorded during 2001 water year and previous highest ground-water levels at selected wells in Puerto Rico.........................................................................7 3. Lowest ground-water levels recorded during 2001 water year and previous lowest ground-water levels at selected wells in Puerto Rico.........................................................................7 VII SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME (Letter after station name designates type of data: (d) discharge, (c) chemical, (b) biological, (s) sediment, (p) pesticide, (e) elevation, gage heights) Station number Page RÍO GUAJATACA BASIN Río Guajataca at Lares (d,c,b) ......................................................................................50010500 52 Lago Guajataca at Damsite near Quebradillas (e).................................................50010800 55 Canal Principal de Diversiones at Lago Guajataca (c,b)..............................................50011000 57 Río Guajataca above mouth near Quebradillas (c,b)....................................................50011400 58 RÍO CAMUY BASIN Río Camuy near Bayaney (d) .......................................................................................50014800 60 RÍO GRANDE DE ARECIBO BASIN Lago Garzas near Adjuntas (e)..............................................................................50020100 64 Río Grande de Arecibo near Adjuntas (d,c,b,s)............................................................50020500 66 Río Pellejas above Central Pellejas (d,s)......................................................................50021030 72 Río Grande de Arecibo above Utuado (d)....................................................................50021700 77 Río Viví below Hacienda El Progreso (d,s) ..........................................................50022810 82 Río Grande de Arecibo below Utuado (d,s) .................................................................50024950 87 Río Grande de Arecibo near Utuado (c,b)....................................................................50025000 92 Río Saliente at Coabey near Jauyuya (d,s) ...................................................................50025155 93 Río Jauca at Paso Palma (d,s).......................................................................................50025850 98 Río Caonillas at Paso Palma (d) ...................................................................................50026025 103 Río Caonillas above Lago Caonillas near Jayuya (c,b)................................................50026050 105 Lago Caonillas at Damsite near Utuado (e) ..........................................................50026140 106 Río Caonillas below Lago Caonillas (d).......................................................................50026200 108 Río Yunes at Highway 140 near Florida (d,s)..............................................................50026400 110 Río Limón above Lago Dos Bocas (d) .........................................................................50027000 114 Lago Dos Bocas at Damsite near Utuado (e) ........................................................50027100 122 Río Grande de Arecibo below Lago Dos Bocas near Florida (d,c,b)...........................50027250 124 Río Grande de Arecibo near San Pedro (d) ..................................................................50027600 129 Río Grande de Arecibo above Arecibo (d)...................................................................50027750 131 Río Tanamá near Utuado (d,c,b,s).........................................................................50028000 133 Río Tanamá at Charco Hondo (d) ........................................................................50028400 139 Río Grande de Arecibo at Central Cambalache (d,c,b) ................................................50029000 141 RÍO GRANDE DE MANATÍ BASIN Río Orocovis at Orocovis (d) ................................................................................50030460 146 Río Orocovis near Orocovis (c,b)..........................................................................50030700 148 Río Grande de Manatí near Morovis (d,c,b).................................................................50031200 149 Lago El Guineo at Damsite near Villalba (e)........................................................50032290 152 Lago de Matrullas at Damsite near Orocovis (e)...................................................50032590 154 Río Bauta near Orocovis (d)..................................................................................50034000 156 Río Grande de Manatí at Ciales (d)..............................................................................50035000 158 Río Grande de Manatí at Highway 149 at Ciales (c,b).................................................50035500 160 Río Cialitos at Highway 649 at Ciales (c,b)..........................................................50035950 161 Río Grande de Manatí at Highway 2 near Manatí (d,c,b,p) .........................................50038100 162 LAGUNA TORTUGUERO BASIN Laguna Tortuguero Outlet near Vega Baja (c,b) ..........................................................50038200 165 VIII SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME--Continued Station number Page RÍO CIBUCO BASIN Río Cibuco below Corozal (d,c,b)................................................................................50038320 168 Río Cibuco at Vega Baja (d,c,b)...................................................................................50039500 171 RÍO DE LA PLATA BASIN Lago Carite at Gate Tower near Cayey (e)...................................................................50039990 176 Río de la Plata at Proyecto La Plata (c,b).....................................................................50043000 178 Río de la Plata at Comerio (d) ......................................................................................50043800 179 Río de la Plata near Comerio (c,b)................................................................................50044000 181 Río Guadiana near Guadiana (d)...........................................................................50044810 182 Río Guadiana near Naranjito (c,b).........................................................................50044850 184 Lago La Plata at Damsite near Toa Alta (e) .................................................................50045000 185 Río de la Plata below La Plata Dam (d) .......................................................................50045010 187 Río de la Plata at Highway 2 near Toa Alta (d,c,b,s,p) ................................................50046000 189 RÍO HONDO BASIN Río Hondo at Flood Channel near Cataño (c,b) ...........................................................50047530 194 RÍO DE BAYAMÓN BASIN Río de Bayamón at Arenas (d)......................................................................................50047535 195 Río Sabana at Vista Monte (d) ..............................................................................50047540 197 Lago de Cidra at Damsite near Cidra (e)......................................................................50047550 199 Río de Bayamón below Cidra Damsite (d)...................................................................50047560 201 Río de Bayamón near Aguas Buenas (c,b)...................................................................50047600 203 Río de Bayamón near Bayamón (d)..............................................................................50047850 204 Río Guaynabo near Bayamón (c,b) .......................................................................50047990 206 Río de Bayamón at Flood Channel at Bayamón (c,b,p) ...............................................50048510 207 RÍO PUERTO NUEVO BASIN Río Piedras: Lago Las Curías at Damsite near Río Piedras (e)..................................................50048680 209 Quebrada Las Curías below Las Curías Damsite (d) ............................................50048690 211 Río Piedras at El Señorial(d).................................................................................50048770 213 Río Piedras near Río Piedras (c,b,p)......................................................................50048800 215 Río Piedras at Hato Rey (d,c,b).............................................................................50049100 217 Laguna San José: Laguna San José No. 2 at San Juan (c,b)...............................................................50049820 220 Bahía de San Juan: Bahía de San Juan No. 5 at San Juan (c,b)............................................................50049920 221 QUEBRADA BLASINA BASIN Quebrada Blasina near Carolina (c,b)...........................................................................50050300 224 RÍO GRANDE DE LOÍZA BASIN Río Grande de Loíza at Quebrada Arenas (d) ..............................................................50050900 225 Quebrada Blanca at El Jagual (d,s)........................................................................50051150 227 Quebrada Salvatierra near San Lorenzo (d,s)........................................................50051180 232 Río Cayaguás at Cerro Gordo (d)..........................................................................50051310 237 Río Grande de Loíza at Highway 183 near San Lorenzo (d,s).....................................50051800 239 Río Turabo above Borinquen (d,s)........................................................................50053025 244 IX SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME--Continued Station number Page RÍO GRANDE DE LOÍZA BASIN--Continued Río Grande de Loíza at Caguas (d,c,b,s) ......................................................................50055000 249 Río Cagüitas: Río Cagüitas near Aguas Buenas (d,s) ..................................................................50055100 255 Río Cagüitas at Villa Blanca at Caguas (d)...........................................................50055225 260 Río Cagüitas at Highway 30 at Caguas (c,b).........................................................50055250 262 Río Bairoa: Río Bairoa at Bairoa (d,s)......................................................................................50055390 263 Río Bairoa near Caguas (c,b).................................................................................50055400 268 Río Gurabo: Río Gurabo below El Mangó (d)...........................................................................50055750 269 Río Valenciano near Juncos (d,s).....................................................................50056400 271 Río Gurabo at Gurabo (d,s) ...................................................................................50057000 276 Río Gurabo near Gurabo (c,b)...............................................................................50057025 281 Río Cañas at Río Cañas (d,s).................................................................................50058350 282 Lago Loíza at Damsite near Trujillo Alto (c,b,e) .........................................................50059000 287 Río Grande de Loíza below Damsite (d)......................................................................50059050 290 Río Grande de Loíza below Trujillo Alto (c,b) ............................................................50059100 292 Río Canóvanas near Campo Rico (d,s).........................................................................50061800 293 RÍO ESPÍRITU SANTO BASIN Quebrada Sonadora near El Verde (d)...................................................................50063440 300 Río Espíritu Santo near Río Grande (d,c,b)..................................................................50063800 302 Río Grande near El Verde (d)................................................................................50064200 305 RÍO MAMEYES BASIN Río Mameyes near Sabana (d,s) ...................................................................................50065500 307 Río Mameyes at Mameyes (d)......................................................................................50066000 312 RÍO SABANA BASIN Río Sabana at Sabana (d)..............................................................................................50067000 314 RÍO FAJARDO BASIN Río Fajardo above Fajardo (d)......................................................................................50070500 316 Río Fajardo near Fajardo (d,c,b,p)................................................................................50071000 318 Río Fajardo below Fajardo (c,b)...................................................................................50072500 322 RÍO BLANCO BASIN Quebrada Guabá near Naguabo (d) ..............................................................................50074950 323 Río Icacos near Naguabo (d) ........................................................................................50075000 325 RÍO HUMACAO BASIN Río Humacao at Las Piedras (d)...................................................................................50081000 344 Río Humacao at Highway 3 at Humacao (c,b).............................................................50082000 346 RÍO GUAYANÉS BASIN Río Guayanés at Yabucoa (c,b,p) .................................................................................50083500 347 Río Guayanés above mouth at Playa de Guayanés (c,b) ..............................................50086500 349 X SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME--Continued Station number Page RÍO MAUNABO BASIN Río Maunabo at Lizas (d) .............................................................................................50090500 350 Río Maunabo at Maunabo (c,b)....................................................................................50091000 352 RÍO CHICO BASIN Río Chico at Providencia (c,b)......................................................................................50091800 353 RÍO GRANDE DE PATILLAS BASIN Río Grande de Patillas near Patillas (d,c,b)..................................................................50092000 354 Río Marín near Patillas (d) ...........................................................................................50093000 357 Lago Patillas at Damsite near Patillas (e).....................................................................50093045 359 RÍO SALINAS BASIN Río Lapa near Rabo del Buey (d) .................................................................................50100200 362 Río Majada at La Plena (d)...........................................................................................50100450 364 RÍO COAMO BASIN Río Coamo at Hwy 14 at Coamo (d) ............................................................................50106100 366 Río Coamo near Coamo (c,b).......................................................................................50106500 368 RÍO DESCALABRADO BASIN Río Descalabrado near Los Llanos (d) .........................................................................50108000 369 RÍO JACAGUAS BASIN Río Toa Vaca above Lago Toa Vaca (d,s)....................................................................50110900 371 Lago Toa Vaca at Damsite near Villaba (e)..........................................................50111210 376 Lago Guayabal at Damsite near Juana Díaz (e) ....................................................50111300 378 Río Jacaguas at Juana Díaz (d).....................................................................................50111500 380 RÍO INABÓN BASIN Río Inabón at Real Abajo (d)........................................................................................50112500 384 RÍO BUCANA BASIN Río Cerrillos above Lago Cerrillos near Ponce (d) ......................................................50113800 386 Lago Cerrillos at Damsite near Ponce (e).....................................................................50113950 388 Río Cerrillos near Ponce (d,c,b) ...................................................................................50114000 390 Río Bucaná at Highway 14 Bridge near Ponce (d).......................................................50114390 393 RÍO PORTUGUÉS BASIN Río Portugués at Tibes (d)............................................................................................50114900 395 Río Portugués near Ponce (c,b) ....................................................................................50115000 397 Río Potugués at Highway 14 near Ponce (d)................................................................50115900 398 Río Portugués at Ponce (c,b,p) .....................................................................................50116200 400 RÍO GUAYANILLA BASIN Río Guayanilla near Guayanilla (d)..............................................................................50124200 402 Río Guayanilla at Central Rufina (c,b,p)......................................................................50124700 404 RÍO YAUCO BASIN Lago Lucchetti at Damsite near Yauco (e)...................................................................50125780 406 XI SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME--Continued Station number Page RÍO LOCO BASIN Lago Loco at Damsite near Yauco (e)..........................................................................50128900 408 Canal de Riego de Lajas below Lago Loco Dam, Yauco (d).......................................50128905 410 Canal de Riego de Lajas above Majinas Filtration Plant (d)........................................50128920 414 Canal de Riego de Lajas below Majinas Filtration Plant (d)........................................50128925 418 Canal de Riego de Lajas below Lajas Filtration Plant, Lajas (d) .................................50128940 422 Canal de Riego de Lajas at Barrio Palmarejo near Lajas (d)........................................50128945 424 Río Loco at Guánica (c,b,p)..........................................................................................50129700 426 RÍO GUANAJIBO BASIN Río Guanajibo at Highway 119 at San Germán (d)......................................................50131990 430 Río Guanajibo near San Germán (c,b)..........................................................................50133600 432 Río Rosario near Hormigueros (d,c,b,s)................................................................50136400 433 Río Guanajibo near Hormigueros (d,c,b,p) ..................................................................50138000 439 RÍO YAGÜEZ BASIN Río Yagüez near Mayagüez (c,b) .................................................................................50138800 444 RÍO GRANDE DE AÑASCO BASIN Lago Guayo at Damsite near Castañer (e).............................................................50141500 445 Río Grande de Añasco near Lares (c,b)........................................................................50143000 447 Río Grande de Añasco near San Sebastián (d,c,b) .......................................................50144000 448 Río Grande de Añasco near Añasco (c,b,p)..................................................................50146000 451 RÍO CULEBRINAS BASIN Río Culebrinas near San Sebastián (c,b).......................................................................50147600 454 Río Culebrinas at Highway 404 near Moca (d)............................................................50147800 455 Río Culebrinas at Margarita Dam near Aguada (d)......................................................50148890 457 Río Culebrinas near Aguada (c,b,p) .............................................................................50149100 459 Analyses of samples collected of water-quality partial-record stations and miscellaneous sites.................................................................................................... 472 ST. THOMAS, U.S. VIRGIN ISLANDS Bonne Resolution Gut at Bonne Resolution (d) ...........................................................50252000 596 Turpentine Run at Mount Zion (d) ...............................................................................50274000 598 ST. JOHN, U.S. VIRGIN ISLANDS Guinea Gut at Bethany (d)............................................................................................50295000 600 ST. CROIX, U.S. VIRGIN ISLANDS Jolly Hill Gut at Jolly Hill (d).......................................................................................50345000 602 XII GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED Page RÍO GUAJATACA BASIN Well 182925067031100 Local number 1001................................................................................................................ 482 Well 182422067015100 Local number 165................................................................................................................. 483 Well 182647066552400 Local number 202................................................................................................................. 484 RÍO CAMUY BASIN Well 182723066511200 Local number 1026................................................................................................................ 485 Well 182431066463400 Local number 1027................................................................................................................ 486 RÍO GRANDE DE ARECIBO BASIN Well 182756066454700 Local number 1051................................................................................................................ 487 Well 182737066370900 Local number 204................................................................................................................. 488 Well 182616066364100 Local number 1052................................................................................................................ 489 Well 182626066345100 Local number 1053................................................................................................................ 490 Well 182603066333601 Local number 1054............................................................................................................... .491 Well 182642066394900 Local number 1055................................................................................................................. 492 Well 182209066340600 Local number 1057................................................................................................................. 493 RÍO GRANDE DE MANATÍ BASIN Well 182544066341500 Local number 205................................................................................................................. 494 Well 182757066325600 Local number 206................................................................................................................. 495 Well 182710066303700 Local number 207................................................................................................................. 496 Well 182549066304300 Local number 166................................................................................................................. 498 Well 182506066280200 Local number 1076................................................................................................................ 499 Well 182308066260400 Local number 210................................................................................................................. 500 RÍO CIBUCO BASIN Well 182614066261500 Local number 1101................................................................................................................ 502 Well 182712066251700 Local number 1102................................................................................................................ 503 Well 182615066235300 Local number 211................................................................................................................. 504 Well 182647066201700 Local number 70.................................................................................................................. 505 Well 182515066194000 Local number 212................................................................................................................. 506 Well 182330066185700 Local number 213................................................................................................................. 508 Well 182426066260400 Local number 1103................................................................................................................ 509 RÍO DE LA PLATA BASIN Well 182526066165001 Local number 1127................................................................................................................ 510 Well 182548066164401 Local number 1128................................................................................................................ 511 Well 182620066163400 Local number 1129................................................................................................................ 512 Well 182620066163403 Local number 1130................................................................................................................ 513 Well 182657066162700 Local number 1131................................................................................................................ 514 Well 182657066162701 Local number 1132................................................................................................................ 515 Well 182654066150600 Local number 1133................................................................................................................ 516 Well 182530066135400 Local number 216................................................................................................................. 517 Well 182655066142400 Local number 217................................................................................................................. 519 Well 180649066095500 Local number 1134................................................................................................................ 520 XIII GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED--Continued Page RÍO HONDO TO RÍO PUERTO NUEVO BASINS Well 182441066082600 Local number 219................................................................................................................. 521 Well 182531066075900 Local number 652................................................................................................................. 522 Well 182511066045401 Local number 1152................................................................................................................ 523 Well 182435066052700 Local number 1153................................................................................................................ 524 Well 182445066043401 Local number 1154................................................................................................................ 525 Well 182443066041502 Local number 1155................................................................................................................ 526 Well 182417066042700 Local number 1156................................................................................................................ 527 Well 182349066032600 Local number 1157................................................................................................................ 528 Well 182406066034700 Local number 1158................................................................................................................ 529 Well 182451066080200 Local number 1159................................................................................................................ 530 RÍO GRANDE DE LOÍZA BASIN Well 181352066025300 Local number 1176................................................................................................................ 531 Well 181311066022500 Local number 1177................................................................................................................ 532 Well 181446066013400 Local number 1178................................................................................................................ 533 Well 181539066014500 Local number 1179................................................................................................................ 534 Well 181550065593200 Local number 50.................................................................................................................. 535 Well 182515065594100 Local number 222................................................................................................................. 537 Well 181540065580300 Local number 1180................................................................................................................ 538 Well 181513065554600 Local number 1181................................................................................................................ 539 RÍO HERRERA TO RÍO ANTÓN RUIZ BASINS Well 182344065490801 Local number 1201................................................................................................................ 540 Well 182223065455900 Local number 1202................................................................................................................ 541 Well 181230065444900 Local number 1203................................................................................................................ 543 Well 182138065431800 Local number 1204................................................................................................................ 544 Well 182131065421100 Local number 1205................................................................................................................ 545 Well 181823065401900 Local number 1206................................................................................................................ 547 Well 181917065382701 Local number 1207................................................................................................................ 548 Well 182234065440000 Local number 1208................................................................................................................ 549 RÍO HUMACAO TO QUEBRADA AGUAS VERDES BASINS Well 180358065503600 Local number 1226................................................................................................................ 550 Well 180415065513900 Local number 96.................................................................................................................. 551 Well 175855066023100 Local number 1227................................................................................................................ 552 Well 175855066050500 Local number 1228................................................................................................................ 553 Well 175728066072200 Local number 1229................................................................................................................ 554 Well 175719066085500 Local number 1230................................................................................................................ 555 Well 175858066100200 Local number 6................................................................................................................... 556 Well 180002066132200 Local number 1231................................................................................................................ 557 Well 180001066122002 Local number 1232................................................................................................................ 559 Well 175947066130601 Local number 1233................................................................................................................ 560 Well 175957066123400 Local number 1234................................................................................................................ 561 Well 175841066104500 Local number 1238................................................................................................................ 562 Well 175814066102200 Local number 1239................................................................................................................ 563 XIV GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED--Continued Page RÍO SALINAS TO RÍO JACAGUAS BASINS Well 175809066133100 Local number 1251................................................................................................................ 564 Well 180206066135500 Local number 1252................................................................................................................ 565 Well 180104066152300 Local number 1253................................................................................................................ 566 Well 175910066155500 Local number 1254................................................................................................................ 568 Well 175903066165000 Local number 1256................................................................................................................ 570 Well 175943066224800 Local number 1257................................................................................................................ 571 Well 175829066232200 Local number 87.................................................................................................................. 572 Well 180020066261500 Local number 1258................................................................................................................ 573 Well 180602066133100 Local number 1260................................................................................................................ 574 Well 175833066145800 Local number 1261................................................................................................................ 575 Well 175735066151800 Local number 1262................................................................................................................ 576 RÍO INABÓN TO RÍO LOCO BASINS Well 175950066354200 Local number 141................................................................................................................. 577 Well 175934066364800 Local number 1276................................................................................................................ 578 Well 180045066381600 Local number 1277................................................................................................................ 580 Well 180156066434000 Local number 1278................................................................................................................ 582 Well 180133066503300 Local number 132................................................................................................................. 583 RÍO GUANAJIBO BASIN Well 180132067033800 Local number 143................................................................................................................. 584 Well 180542067084000 Local number 1301................................................................................................................ 585 Well 180628067084300 Local number 1302................................................................................................................ 586 Well 180628067084301 Local number 1303................................................................................................................ 588 RÍO YAGÜEZ TO RÍO GRANDE DE AÑASCO BASINS Well 181232067083700 Local number 1326................................................................................................................ 590 RÍO CULEBRINAS BASIN Well 182017067143300 Local number 1352................................................................................................................ 591 Well 182442067091700 Local number 200................................................................................................................. 593 ST. CROIX, U.S. VIRGIN ISLANDS Well 174225064472000 Local number 2...................................................................................................................... 606 Well 174243064475100 Local number 3...................................................................................................................... 607 Well 174316064480800 Local number 13.................................................................................................................... 609 ST. THOMAS, U.S. VIRGIN ISLANDS Well 182038064550300 Local number 6...................................................................................................................... 611 Well 182038064580000 Local number 8...................................................................................................................... 612 ST. JOHN, U.S. VIRGIN ISLANDS Well 181956064464500 Local number 11.................................................................................................................... 613 XV DISCONTINUED STREAMFLOW STATIONS The following continuous-record streamflow stations in Puerto Rico and the U.S. Virgin Islands have been discontinued or converted to partial-record stations. Daily streamflow or stage records were collected for the period of record shown for each station. Station Station name Drainage Period of number area (mi2) record 50007000 Quebrada de los Cedros near Isabela 6.91 1970 50010600 Río Guajataca above Lago de Guajataca -- 1984-89 50011000 Canal Diversion Lago Guajataca -- 1970 50011200 Río Guajataca below Lago Guajataca -- 1969-70,1984-87 50011400 Río Guajataca above mouth near Quebradillas -- 1969-70,1984-89 50013000 Río Camuy near Lares 7.62 1969-71 50014000 Río Criminales near Lares 4.68 1969-70 50014600 Río Camuy at Tres Pueblos Sinkhole -- 1990-96 50015700 Río Camuy near Hatillo -- 1984-96 50016000 Río Camuy near Camuy -- 1969-73 50021050 Río Pellejas below Central Pellejas 7.89 1972-75 50021500 Río Pellejas near Utuado 9.55 1969-71 50023000 Río Viví near Central Pellejas 5.66 1969-75 50027200 Río Grande de Arecibo blw. Lago dos Bocas 169 1970-71 50031500 Río Sana Muerto near Orocovis 3.68 1965-70 50035200 Río Grande de Manatí at Hwy 145 at Ciales 132 1972 50035950 Río Cialitos at Hwy 649 at Ciales 17 1970-82 50038360 Río Mavilla near Corozal 9.51 1969-70 50038600 Río Unibón near Morovis 5.29 1969-70 50038700 Río Morovis at Morovis 1.26 1968 50038900 Río Indio at Vega Baja -- 1963,66,71 50039600 Río Cibuco at Central San Vicente -- 1969-72 50043200 Río Usabon near Barranquitas 9.15 1968-69,71 50043400 Río Aibonito Tributary near Aibonito 1.13 1968-71 50044600 Río Guadiana near Naranjito 1.73 1971 50044650 Quebrada del Toro near Naranjito 0.54 1971 50044800 Quebrada Anones near Naranjito 2.32 1971 50045700 Río Lajas at Toa Alta 8.65 1966-75 50047820 Río de Bayamón at Hwy 174 near Bayamón 31.90 1966 50048000 Río de Bayamón at Bayamón 71.90 1963-67 50049000 Río Piedras at Río Piedras 12.5 1971-82, 1987-93 50049310 Quebrada Josefina at Piñero Avenue 3.84 1988-91 50053050 Río Turabo at Borinquen 7.89 1984-90 50054000 Quebrada de las Quebradillas near Caguas 6.25 1969-71,73 50055170 Río Cagüitas near Caguas 8.27 1992-97 50055650 Quebrada Caimito near Juncos 0.82 1984-87 50056000 Río Valenciano near Las Piedras 6.85 1971 50056900 Quebrada Mamey near Gurabo 2.30 1984-92 50058300 Quebrada Arena near Caguas -- 1971 50061300 Río Canovanillas near Loíza 14.40 1968-73 XVI DISCONTINUED STREAMFLOW STATIONS--Continued Station Station name Drainage Period of number area (mi2) record 50062500 Río Herrera near Colonia Dolores 2.75 1968-72 50063300 Río Espíritu Santo near El Verde 2.23 1968-73 50063500 Quebrada Toronja at El Verde 0.064 1983-96 50065700 Río Mameyes at Hwy 191 at Mameyes 11.80 1967-85 50072000 Río Fajardo at Fajardo 21.60 1960-63 50073200 Río Daguao at Daguao 2.26 1966-82 50073400 Quebrada Palma at Daguao 4.84 1972-77 50074000 Río Santiago at Naguabo 4.99 1966-82 50075500 Río Blanco at Florida 11.00 1966-82 50076000 Río Blanco near Florida 12.30 1983-85 50077000 Río Blanco at Río Blanco 17.60 1973-77 50077400 Río Blanco at Colonia La Fe 18.80 1967-70 50078500 Río Anton Ruíz at Central Pasto Viejo 4.33 1968 50081500 Río Humacao near Humacao 9.23 1973 50082000 Río Humacao at Hwy 3 at Humacao 17.30 1983-85 50082200 Río Humacao near La Suiza 19.90 1965-66, 1969-71 50082800 Río Guayanés near Colonia Laura 4.69 1969-82 50083500 Río Guayanés near Yabucoa 17.20 1969-71 50084000 Río Limones near Yabucoa 7.89 1969-71 50085100 Río Guayanés at Central Roig 26.60 1965-66, 1968,70 50086100 Río del Ingenio at Comunas 5.50 1965-66, 1968-69 50086500 Río Guayanés at Playa Guayanés 34.00 1965-66, 1968-71 50087200 Caño Santiago near Central Roig 6.04 1965-71 50091000 Río Maunabo at Maunabo 12.40 1965,67, 1969-82 50091200 Río Maunabo near Maunabo 12.70 1971-72 50091400 Río Jacaboa near Lamboglia 4.13 1965-73 50091700 Río Chico at Patillas 6.82 1965, 1969-72 50091800 Río Chico at Providencia 4.90 1965, 1967-69, 1971 50094200 Río Grande de Patillas at Patillas 27.90 1967, 1969, 1971 50094300 Río Grande de Patillas at Providencia 29.00 1971 50094400 Río Nigua at Pitahaya 5.86 1965, 1969, 1970-71, 1973 50095200 Río Guamaní at Guayama 8.22 1969-71 50095500 Río Guamaní near Guayama 12.30 1969-70 50099000 Quebrada Aguas Verdes near Salinas 0.39 1989 50106500 Río Coamo near Coamo 46.00 1967-68, 1984-85, 1986 50106900 Río Coamo below Lago Coamo near Coamo 65.40 1967-68 50107200 Río Coamo at mouth near Santa Isabel 69.30 1967-68 50108200 Río Descalabrado at Las Ollas 13.90 1965, 1967-71 50108500 Río Descalabrado near Santa Isabel 18.10 1966-67 50111200 Río Toa Vaca near Villalba 21.40 1966-70 XVII DISCONTINUED STREAMFLOW STATIONS--Continued Station Station name Drainage Period of number area (mi2) record 50111700 Río Jacaguas near Juana Díaz 53.20 1966-68 50111750 Río Jacaguas below Quebrada Guanábana 56.30 1989 50112100 Río Jacaguas near Arús 59.60 1966-67 50112600 Río Inabón at Coto Laurel -- 1967-71 50113100 Río Guayo near Coto Laurel 11.80 1965, 1968-71 50113500 Río Inabón near Arús 30.20 1964-65 50114400 Río Bucaná near Ponce 25.60 1965-81 50114700 Río Bucaná near Playa de Ponce 28.40 1964-67 50115000 Río Portugués near Ponce 8.82 1964-97 50116500 Río Portugués at Highway 2 Bypass at Ponce 20.50 1964-65 50119000 Río Matilde at Ponce 19.40 1965-66 50121000 Río Tallaboa at Peñuelas 24.20 1959-82 50122000 Río Tallaboa at Tallaboa 31.50 1959-63 50124000 Río Guayanilla nr Guayanilla 18.50 1961-69 50124500 Río Guayanilla at Guayanilla 20.80 1971-82 50125900 Río Duey above Diversion near Yauco 8.93 1977-80 50126150 Río Yauco above Diversion Monserrate near Yauco 27.20 1978-85 50128000 Río Yauco near Yauco 45.50 1962-64, 1977-85 50129000 Río Loco near Yauco 8.50 1963-67 50129500 Río Loco near Guánica 21.00 1963-69 50129900 Laguna Cartagena near Boquerón -- 1984-86 50130320 Quebrada Mamey at Joyuda 0.38 1986-88 50136000 Río Rosario at Rosario 16.40 1975-86 50141000 Río Yahuecas near Adjuntas 15.40 1980-85 50145000 Río Grande de Añasco at El Espino 108.00 1959-66, 1961-63 50147000 Río Culebrinas at San Sebastian 16.70 1960-82 50214500 Quebrada Resaca near Monte Resaca, Culebra 0.23 1991-93 50215000 Drainage Canal at Culebra Airport, Culebra 0.08 1991-93 50231000 Quebrada Confresí Tributary near Isabel II, Vieques 0.28 1991-93 50232000 Quebrada La Mina near Esperanza, Vieques 0.68 1991-96 50233000 Quebrada Pilón at Colonia Puerto Real, Vieques 0.67 1991-96 50276000 Turpentine Run at Mariendal, St.Thomas 2.97 1963-69, 1978-86 50292600 Lameshur Bay Gut at Lameshur, St. John 0.38 1992-94 50294000 Fish Bay Gut at Fish Bay, St. John 1.48 1992-94 50295500 Cruz Bay Gut at Cruz Bay, St. John, VI 0.09 1992-93 50332000 River Gut at River 1.42 1991-93 50333500 River Gut near Golden Grove 5.40 1990-93 50333700 River Gut at Hwy 66 at Fairplanes 5.89 1990-96 50334500 Bethehem Gut at Hwy 66 at Fairplanes 4.11 1990-96 50337500 Gut 4.5 at Cane Valley 0.2 1991-93 50348000 Salt River at Canaan 0.36 1991-93 50349000 Gut 10 near Altona 0.13 1991-93 XVIII THIS PAGE IS INTENTIONALLY BLANK 1 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 INTRODUCTION The Water Resources Division of the U.S. Geological Survey, in cooperation with local and Federal agencies obtains a large amount of data pertaining to the water resources of the Commonwealth of Puerto Rico and the Territory of the U.S. Virgin Islands each water year. These data, accumulated during many water years, constitute a valuable data base for developing an improved understanding of the water resources of the area. To make these data readily available to interested parties outside the U.S. Geological Survey, the data are published annually in this report series entitled "Water Resources Data for Puerto Rico and the U.S. Virgin Islands, 2001." This report includes records on both surface and ground water. Specifically, it contains: (1) discharge records for 95 streamflow gaging stations, daily sediment records for 23 streamflow stations, 20 partial-record or miscellaneous streamflow stations, stage records for 18 reservoirs, and (2) water-quality records for 17 streamflow-gaging stations, and for 42 ungaged stream sites, 11 lake sites, 2 lagoons, and 1 bay, and (3) water-level records for 103 observation wells. Water-resources data for Puerto Rico for calendar years 1958-67 were released in a series of reports entitled "Water Records of Puerto Rico." Water-resources data for the U.S. Virgin Islands for the calendar years 1962-69 were released in a report entitled "Water Records of U.S. Virgin Islands." Included were records of streamflow, ground- water levels, and water-quality data for both surface and ground water. Beginning with the 1968 calendar year, surface-water records for Puerto Rico were released separately on an annual basis. Ground-water level records and water-quality data for surface and ground water were released in companion reports covering periods of several years. Data for the 1973-74 reports were published under separate covers. Water-resources data reports for 1975 to 2000 water years consist of one volume each and contain data for streamflow, water quality, and ground water. Publications similar to this report are published annually by the U.S. Geological Survey for all States. These official Survey reports have an identification number consisting of the two-letter State abbreviation, the last two digits of the water year, and the volume number. For example, this volume is identified as "U.S. Geological Survey Water- Data Report PR-01-1." These water-data reports are for sale in paper copy or in microfiche by the National Technical Information Service, U.S. Department of Commerce, Springfield, Virginia, 22161. Additional information, including current prices, for ordering specific reports may be obtained from the District Chief at the address given on back of the title page or by telephone (787) 749-4346. 2 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 COOPERATION The U.S. Geological Survey has had cooperative agreements with organizations of the Commonwealth of Puerto Rico and the Territory of the U.S. Virgin Islands for the systematic collections of water resources data since 1958. Organizations that supplied data are acknowledged in the station descriptions. Organizations that assisted in collecting data through cooperative agreements with the U.S. Geological Survey are: Puerto Rico Environmental Quality Board Puerto Rico Aqueduct and Sewer Authority Puerto Rico Department of Agriculture Puerto Rico Industrial Development Company Puerto Rico Highway Authority Puerto Rico Department of Natural and Environmental Resources Puerto Rico Department of Health Puerto Rico Electric Power Authority Puerto Rico Solid Waste Management Authority Puerto Rico Legislature Puerto Rico Emergency Management Agency U.S. Virgin Islands Department of Planning and Natural Resources Puerto Rico Infrastructure Financing Authority Funds were also provided by the U.S. Army, Corps of Engineers, for the collection of records at six gaging stations published in this report. 3 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 SUMMARY OF HYDROLOGIC CONDITIONS Rainfall Rainfall throughout Puerto Rico during the water year 2001 (October 2000 to September 2001) was deficient, with an average of 88 percent of normal. The months of April, May, July, and August were the only periods when rainfall was slightly above normal with averages that ranged from 5 to 12 percent above normal. Rainfall was below the normal range, fluctuating between 4 of 37 percent below normal for the rest of the year. Rainfall during the water year averaged 83 percent of normal in northern and eastern Puerto Rico, 96 percent of normal in southern Puerto Rico, and 93 percent of normal in western Puerto Rico. In the U.S. Virgin Islands, rainfall was also deficient, with an average of 70 percent of normal. Normal rainfall is defined as the mean monthly rainfall for the period 1961-1990 (table 1). Table 1. Islandwide monthly rainfall for the water year 2001 and annual averages for the 30-year reference period, 1961-90 Data from the National Oceanographic and Atmospheric Administration ____________________________________________________ 2001 Water Year 30-year normal Month (inches) (inches) ____________________________________________________ October 6.82 8.29 November 4.48 6.55 December 2.84 4.38 January 2.66 2.87 February 2.43 2.53 March 2.14 3.02 April 4.66 4.44 May 7.77 6.96 June 3.14 5.00 July 5.44 5.09 August 7.30 6.89 September 6.01 7.14 TOTAL 55.69 63.16 ____________________________________________________ Surface Water Streamflow in Puerto Rico during most of the 2001 water year was below normal, except in the southern area where the monthly mean flows exceeded the long-term median of the monthly mean flows for seven months, based on the four index stations. During December, February, and June, below normal flows were recorded at the four index stations. A comparison of the monthly mean flows during the 2001 water year with the long-term minimum, median, and maximum of the monthly mean flows, for the period of record at the index stations on the Río Grande de Manatí (northern area), the Río Fajardo (eastern area), the Río Inabón (southern area), and the Río Grande de Añasco (western area) are shown in figure 1. The following overview of the four areas represented by the index stations describes the hydrologic conditions in more detail. In the northern area, the Río Grande de Manatí index station recorded monthly mean flows that were below normal for ten consecutive months (December to September). Below normal monthly mean flows ranged from 40 to 86 percent of normal. During October and November, the long-term median was exceeded by 1 and 145 percent, respectively. In the eastern area, the Río Fajardo index station recorded monthly mean flows below the long-term median for most of the 2001 water year, except during March when the monthly mean flow equaled the long-term median of the monthly mean flows. Monthly mean flows ranged from 29 to 82 percent of the long-term median. 4 Figure 1. Monthly-mean discharge of selected streams in Puerto Rico. 5 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 The southern area, represented by the Río Inabón index station, was the only area in Puerto Rico where the monthly mean flows exceeded the long-term median for most of the water year. Monthly mean flows were above normal in January, March, April, May, July, August, and September, ranging from 115 to 138 percent of normal. Below normal monthly mean flows, ranging from 57 to 98 percent of the long-term median, were registered in the Río Inabón index station during the months of October, November, December, February, and June. In the western area experienced below normal flow conditions for eight months. Monthly mean flows recorded at the index station on the Río Grande de Añasco ranged from 69 to 98 percent of the long-term median during November, December, January, February, March, June, August, and September. In October, April, May, and July, monthly mean flows ranging from 104 to 163 percent of normal were registered at the index station. Streamflow in the U.S. Virgin Islands during 2001 water year were, in general, below normal conditions. In St. Thomas, historical minimum monthly mean flows were recorded during November, December, and June in the eastern area and during August in the north-central area. In north-central St. Thomas, the minimum monthly mean flow for July was equaled. During May, the monthly mean flow was above normal in north-central St. Thomas. In St. John, the streamflow conditions were below normal for the water year, except during March, when the monthly mean flow was above normal. In St. Croix, a historical maximum was recorded during May and minimum monthly mean flows were equaled during March, April, August, and September. Monthly mean flows were below normal for the rest of the water year. Ground Water Water-level trends and fluctuations during the water year 2001 followed a pattern resulting from below normal rainfall accumulation combined with continuous but moderate ground-water withdrawals (fig. 2). Water-level measurements indicate the depth at which water is found in tightly cased wells. For all the index wells shown in figure 2, net seasonal change in water-level reported as feet below land surface for water year 2001 is greater than zero. This is an indication of water depletion from storage in limestone and alluvial aquifers along the north and south coast of Puerto Rico, and also within fractured-rock volcanic aquifers in St. John, U.S. Virgin Islands. The highest water-level recorded was near or above the historic high at five ground-water monitoring stations (table 2). In areas where ground-water withdrawals constitute an important resource for drinking water purposes, the lowest water-level recorded was near or below the historic low in 14 ground-water monitoring stations (table 3). For water year 2001, rainfall distribution in Puerto Rico climatic subdivisions at which the principal aquifer systems are found was as follow: North Coast limestone, 80 percent of normal; South Coastal Plain, normal; Eastern alluvials, 83 percent of normal; Western alluvials, 93 percent of normal. For water year 2001 rainfall distribution in the U.S. Virgin Islands climatic subdivisions at which the principal aquifers are found was in general 70 percent of normal. The period of record of many of the ground-water monitoring sites dates to 1997. Fluctuations observed at these monitoring sites during water year 2001 were comparable to historic ground-water levels at index stations obtained since the 1960's. Figures 7 and 9 show the locations of the ground-water stations maintained by the USGS in Puerto Rico and the U.S. Virgin Islands. 6 Figure 2. Ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands. 7 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Table 2. Highest ground-water levels recorded during 2001 water year and previous highest ground-water levels at selected wells in Puerto Rico [PR, Puerto Rico; mm-dd-yy, month-day-year; ft-blsd, feet below land-surface datum; mm-yy, month-year] ______________________________________________________________________________________________________________________ 2001 Previous Highest highest water water Period of Well Local level Date level Date record name number Location (ft-blsd) (mm-dd-yy) (ft-blsd) (mm-dd-yy) (mm-yy) ______________________________________________________________________________________________________________________ Campo Alegre 1027 PR 182.42 06-19-01 183.50 04-09-99 09-96 to 06-01 4 Piezometer 1159 PR 27.56 09-29-01 29.43 05-31-99 09-97 to 09-01 Fort Buchanan 09-30-01 1 Piezometer 1226 PR +0.26 08-23-01 +0.29 11-17-99 09-97 to 09-01 Yabucoa USGS Brackish Albergue de 1277 PR 24.42 11-08-00 24.62 12-13-99 03-92 to 09-01 Niños 11-09-00 CR-TW-9B 1303 PR 4.88 09-28-01 6.18 11-23-96 07-92 to 09-01 ______________________________________________________________________________________________________________________ Table 3. Lowest ground-water levels recorded during 2001 water year and previous lowest ground-water levels at selected wells in Puerto Rico [PR, Puerto Rico; mm/dd/yy, month/day/year; ft-blsd, feet below land-surface datum; mm/yy, month/year] ______________________________________________________________________________________________________________________ 2001 Previous Highest highest water water Period of Well Local level Date level Date record name number Location (ft-blsd) (mm-dd-yy) (ft-blsd) (mm-dd-yy) (mm-yy) ______________________________________________________________________________________________________________________ Zanja 4 1026 PR 339.75 09-05-01 338.60 07-07-00 02-97 to 09-01 Campo Alegre 1027 PR 218.64 02-02-01 212.60 05-28-98 09-96 to 06-01 4 Tiburones 1053 PR 292.33 04-13-01 292.29 01-17-97 05-96 to 09-01 1 04-14-01 Florida Afuera 1054 PR 201.66 04-13-01 201.63 04-10-98 08-96 to 09-01 2 04-14-01 04-11-98 04-15-01 04-12-98 NC-5 Cruce 205 PR 92.21 08-06-01 90.24 10-08-99 12-86 to 09-01 Dávila Palo Alto 1101 PR 240.24 06-11-01 240.14 08-18-98 05-96 to 09-01 2 Piezometer 1128 PR 29.37 06-23-01 29.05 07-20-95 06-95 to 09-01 Maguayo USGS 06-24-01 07-21-95 2 07-22-95 Piezometer 1132 PR 19.05 04-21-01 19.03 05-13-95 10-94 to 09-01 San Antonio USGS 3 Piezometer 1133 PR 11.19 04-19-01 10.68 05-03-95 11-92 to 09-01 Toa Baja 04-20-01 05-04-95 USGS 1 Piezometer Quebrada Mata 1208 PR 6.03 08-19-01 5.96 08-22-00 09-97 to 09-01 de Platanos to 08-22-01 Piezometer 1226 PR 6.19 07-14-01 5.90 08-09-99 09-97 to 09-01 Yabucoa USGS 08-10-99 Brackish 08-11-99 Fidel 2 Well 1227 PR 29.42 08-22-01 27.80 08-16-98 12-96 to 09-01 to 08-28-98 Algarrobo 1228 PR 34.19 07-19-01 34.17 07-06-99 05-97 to 09-01 Domestic 07-20-01 to Well 07-11-99 08-22-99 08-23-99 VIEO-6-Kirwan 8 St.T 33.97 07-29-01 32.70 04-27-95 10-91 to 09-01 Terrace 07-31-01 ______________________________________________________________________________________________________________________ 8 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Water Quality The U.S. Geological Survey, in cooperation with several local government agencies, collected water-quality data at 74 surface-water stations during water year 2001. Water-quality data collected at these stations included the trace elements, nutrients, pesticides, as well as fecal indicator bacteria and physical parameters. The presence of high concentrations of fecal coliform (fig. 3) and fecal streptococcal (fig. 4) bacteria continued to be one of the principal water-quality problems in Puerto Rico during water year 2001. The highest concentrations of these fecal indicator bacteria were determined from samples collected within the drainage basins in metropolitan areas with the highest population such as San Juan, Caguas, Ponce, and Mayagüez. Areas drained by major rivers where there is intense land use (agriculture, industry, urbanization) also have problems with fairly high concentrations of fecal indicator bacteria. These include the municipios of Aguadilla, Añasco, Arecibo, Humacao, and Manatí. The ability of communities to treat drinking water for bacteria is often inhibited by runoff with high suspended-sediment concentration and the associated turbidity problems. This is generally the case in streams which suffer from intense resource utilization (agriculture and urban development) where soil movement is involved. High suspended-sediment concentrations affect the quality of drinking water and reduce the storage capacity of reservoirs. SPECIAL NETWORKS AND PROGRAMS Hydrologic Bench-Mark Network is a network of 57 sites in small drainage basins around the country whose purpose is to provide consistent data on the hydrology, including water quality, and related factors in representative undeveloped watersheds nationwide, and to provide analyses on a continuing basis to compare and contrast conditions observed in basins more obviously affected by the activities of man. National Stream Quality Accounting Network (NASQAN) is a nationwide data-collection network designed by the U.S. Geological Survey to meet many of the information needs of government agencies and other groups involved in natural or regional water-quality planning and management. The 500 or so sites on NASQAN are generally located at the downstream ends of hydrologic accounting units designated by the U.S. Geological Survey Office of Water Data Coordination in consultation with the Water Resources Council. The objectives of NASQAN are (1) to obtain information on the quality and quantity of water moving within and from the United States through a systematic and uniform process of data collection, summarization, analysis, and reporting such that the data may be used for, (2) description of the areal variability of water quality in the Nation's rivers through analysis of data from this and other programs, (3) detection of changes or trends with time in the pattern of occurrence of water-quality characteristics, and (4) providing a nationally consistent data base useful for water-quality assessment and hydrologic research. The National Trends Network (NTN) is a 150-station network for sampling atmospheric deposition in the United States. The purpose of the network is to determine the variability, both in location and in time, of the composition of atmospheric deposition, which includes snow, rain, dust particles, aerosols, and gases. The core from which the NTN was built was the already-existing deposition-monitoring network of the National Atmospheric Deposition Program (NADP). The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey is a long-term program with goals to describe the status and trends of water-quality conditions for a large, diverse, and geographically distributed part of the Nation's ground- and surface-water resources, and to identify, describe, and explain the major natural and human factors that affect these observed conditions and trends. Assessment activities have begun in more than one-third of the study units and ultimately will be conducted in 60 study units (major watersheds and aquifer systems) that represent a wide range of environmental settings nationwide and that account for a large percentage of the Nation's water use. A wide array of chemical constituents will be measured in ground water, surface water, streambed sediments, and fish tissues. The coordinated application of comparative hydrologic studies at a wide range of spatial and temporal scales will provide information for decision making by water-resources managers and a foundation for aggregation and comparison of findings to address water- quality issues of regional and national interest. 9 Figure 3. Location of maximum concentrations of fecal coliform bacteria at the water-quality sampling sites in Puerto Rico. 10 Figure 4. Location of maximum concentrations of fecal streptococci bacteria at the water-quality sampling sites in Puerto Rico. 11 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Radiochemical Programs is a network of regularly sampled water-quality stations where samples are collected to be analyzed for radioisotopes. The streams that are sampled represent major drainage basins in the conterminous United States. Tritium Network is a network of stations which has been established to provide baseline information on the occurrence of tritium in the Nation's surface waters. In addition to the surface-water stations in the network, tritium data are also obtained at a number of precipitation stations. The purpose of the precipitation stations is to provide an estimate sufficient for hydrologic studies of the tritium input to the United States. EXPLANATION OF RECORDS The surface- and ground-water records published in this report are for the 2001 water year that began October 1, 2000 and ended September 30, 2001. A calendar of the water year is provided on the inside of the front cover. The records contain streamflow data, water-quality data for surface and ground water, and ground-water-level data. The locations of the stations and wells where the data were collected are shown in figures 3 to 9. The following sections of the introductory text are presented to provide users with a more detailed explanation of how the hydrologic data published in this report were collected, analyzed, computed, and arranged for presentation. Station Identification Numbers Each data station, whether stream site or well, in this report is assigned a unique identification number. This number is unique in that it applies specifically to a given station and to no other. The number usually is assigned when a station is first established and is retained for that station indefinitely. The systems used by the U.S. Geological Survey to assign identification numbers for surface-water stations and for ground-water well sites differ, but both are based on geographic location. The "downstream order" system is used for regular surface-water stations and the "latitude-longitude" system is used for wells. Downstream Order System Since October 1, 1950, the order of listing hydrologic-station records in Survey reports is in a downstream direction along the main stream. All stations on a tributary entering upstream from a main-stream station are listed before that station. A station on a tributary that enters between two main-stream stations is listed between them. A similar order is followed in listing stations in first rank, second rank, and other ranks of tributaries. As an added means of identification, each hydrologic station and partial-record station has been assigned a station number. These are in the same downstream order used in this report. In assigning station numbers, no distinction is made between partial-record stations and other stations; therefore, the station number for a partial-record station indicates downstream order position in a list made up of both types of stations that may be established; hence, the numbers are not consecutive. The complete 8-digit number for each station such as 50028000, which appears just to the left of the station name, includes the 2-digit part number "50" plus the 6-digit downstream order number "028000." Latitude-Longitude System The 8-digit downstream order station numbers are not assigned to wells and miscellaneous sites where only random water-quality samples or discharge measurements are taken. The well and miscellaneous site numbering system of the U.S. Geological Survey is based on the grid system of latitude and longitude. The system provides the geographic location of the well or miscellaneous site and a unique number for each site. The number consists of 15 digits. The first 6 digits denote the degrees, minutes, and seconds of latitude, the next 7 digits denote degrees, minutes, and seconds of longitude, and the last 2 digits (assigned sequentially) identify the wells or other sites within a 1-second grid. The numbers shown in the grid correspond to the local numbers assigned to each well as visited in the field. An example is well 16 (fig. 10). 12 Figure 5. Location of surface-water stations in Puerto Rico. 13 Figure 6. Location of water-quality stations in Puerto Rico. 14 Figure 7. Location of ground-water stations in Puerto Rico. 15 Figure 8. Location of surface-water stations in the U.S. Virgin Islands. 16 Figure 9. Location of ground-water stations in the U.S. Virgin Islands. 17 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Figure 10. Grid showing system for numbering wells and miscellaneous sites (latitude and longitude). Records of Stage and Water Discharge Records of stage and water discharge may be complete or partial. Complete records of discharge are those obtained using a continuous stage-recording device through which either instantaneous or mean daily discharges may be computed for any time, or any period of time, during the period of record. Complete records of lake or reservoir content, similarly, are those for which stage or content may be computed or estimated with reasonable accuracy for any time, or period of time. They may be obtained using a continuous stage-recording device, but need not be. Because daily mean discharges and end-of-day contents commonly are published for such stations, they are referred to as "daily stations." By contrast, partial records are obtained through discrete measurements without using a continuous stage- recording device and pertain only to a few flow characteristics, or perhaps only one. The nature of the partial record is indicated by table titles such as "Low-flow partial records." Records of miscellaneous discharge measurements or of measurements from special studies, such as low-flow seepage studies, may be considered as partial records, but they are presented separately in this type of report. Location of all complete-record stations for which data are given in this report are shown in figures 5 and 8. Data Collection and Computation The data obtained at a complete-record gaging station on a stream or canal consists of a continuous record of stage, individual measurements of discharge throughout a range of stages, and notations regarding factors that may affect the relationships between stage and discharge. These data, together with supplemental information, such as weather records, are used to compute daily discharges. The data obtained at a complete-record gaging station on a lake or reservoir consist of a record of stage and of notations regarding factors that may affect the relationship between stage and lake content. These data are used with stage-area and stage-capacity curves or tables to compute water-surface areas and lake storage. Continuous records of stage are obtained with analog recorders that trace continuous graphs of stage or with digital recorders that punch stage values on paper tapes at selected time intervals or electronic satellite data collector platforms that receive stage values at selected time intervals. Measurements of discharge are made with current meters using methods adapted by the Geological Survey as a result of experience accumulated since 1880. These methods are described in standard textbooks, in Water-Supply Paper 2175, and in U.S. Geological Survey Techniques of Water- Resources Investigations, Book 3, Chapter A6. 134 132 131 27 74 16 COORDINATES FOR WELLS 27 (180150066474900) AND 74 (180135066471000) COORDINATES FOR WELLS 132 (180133066503300) AND 134 (180120066503200) COORDINATES FOR WELLS 131 (180058066502700) COORDINATES FOR WELLS 16 (175922066495800) 18 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 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. 19 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 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. 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. 20 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 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. Statistics of Monthly Mean Data A tabular summary of the mean (line headed "MEAN"), maximum (line headed "MAX"), and minimum (line headed "MIN") of monthly mean flows for each month for a designated period is provided below the mean values table. The water years of the first occurrence of the maximum and minimum monthly flow are provided immediately below those figures. The designated period will be expressed as "FOR WATER YEARS ____-____, BY WATER YEAR (WY)," and will list the first and last water years of the range of years selected from the PERIOD OF RECORD paragraph in the station manuscript. It will consist of all of the station records within the specified water years, including complete months of record for partial water years, if any, and may coincide with the period of record for the station. The water years for which the statistics are computed will be consecutive, unless a break in the station record is indicated in the manuscript. Summary Statistics A table titled "SUMMARY STATISTICS" follows the statistics of monthly mean data tabulation. This table consists of four columns, with the first column containing the line headings of the statistics being reported. The table provides a statistical summary of yearly, daily, and instantaneous flows, not only for the current water year but also for the previous calendar year and for a designated period, as appropriate. The designated period selected, "WATER YEARS ____-____," will consist of all of the station records within the specified water years, inclusive, including complete months of record for partial water years, if any, and may coincide with the period of record for the station. The water years for which the statistics are computed will be consecutive, unless a break in the station record is indicated in the manuscript. All of the calculations for the statistical characteristics designated ANNUAL (see line headings below), except for the "ANNUAL 7-DAY MINIMUM" statistic, are calculated for the designated period using complete water years. The other statistical characteristics may be calculated using partial water years. The date or water year, as appropriate, of the first occurrence of each statistic reporting extreme values of discharge is provided adjacent to the statistic. Repeated occurrences may be noted in the REMARKS paragraph of the manuscript or in footnotes. Because the designated period may not be the same as the station period of record published in the manuscript, occasionally the dates of occurrence listed for the daily and instantaneous extremes in the designated-period column may not be within the selected water years listed in the heading. When this occurs, it will be noted in the REMARKS paragraph or in footnotes. Selected streamflow duration curve statistics and runoff data are also given. Runoff data may be omitted if there is extensive regulation or diversion of flow in the drainage basin. 21 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 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). MAXIMUM 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.) MAXIMUM PEAK STAGE.--The maximum instantaneous stage occurring for the water year or for the designated period. If the dates of occurrence for the instantaneous peak flow and instantaneous peak stage differ, the REMARKS paragraph in the manuscript or a footnote may be used to provide further information. INSTANTANEOUS LOW FLOW.--The minimum instantaneous discharge occurring for the water year or for the designated period. ANNUAL RUNOFF.--Indicates the total quantity of water in runoff for a drainage area for the year. Data reports may use any of the following units of measurements in presenting annual runoff data: Acre-foot (AC-FT) is the quantity of water required to cover 1 acre to a depth of 1 foot and is equivalent to 43,560 cubic feet or about 326,000 gallons or 1,233 cubic meters. Cubic feet per second per square mile (CFSM) is the average number of cubic feet of water flowing per second from each square mile of area drained, assuming the runoff is distributed uniformly in time and area. Inches (INCHES) indicates the depth to which the drainage area would be covered if all of the runoff for given time period were uniformly distributed on it. 10 PERCENT EXCEEDS.--The discharge that is exceeded 10 percent of the time for the designated period. 50 PERCENT EXCEEDS.--The discharge that is exceeded 50 percent of the time for the designated period. 90 PERCENT EXCEEDS.--The discharge that is exceeded 90 percent of the time for the designated period. 22 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Data collected at partial-record stations follow the information for continuous-record sites. Data for partial-record discharge stations are presented in a table of discharge measurements at low-flow partial-record stations. These measurements are generally made in times of drought to give better areal coverage to those events. Those measurements and others collected for some special reason are called measurements at miscellaneous sites. Identifying Estimated Daily Discharge Estimated daily-discharge values published in the water-discharge tables are identified by flagging individual daily values with the letter symbol "e" and printing a table footnote, "e Estimated." Accuracy of the Records The accuracy of streamflow records depends primarily on: (1) The stability of the stage-discharge relation or, if the control is unstable, the frequency of discharge measurements; and (2) the accuracy of measurements of stage, measurements of discharge, and interpretation of records. The accuracy attributed to the records is indicated under "REMARKS." "Excellent" means that about 95 percent of the daily discharges are within 5 percent of the true; "good," within 10 percent; and "fair," within 15 percent. Records that do not meet the criteria mentioned, are rated "poor." Different accuracies may be attributed to different parts of a given record. Daily mean discharges in this report are given to the nearest hundredth of a cubic foot per second for values less than 1 ft3/s; to the nearest tenth between 1.0 and 10 ft3/s; to whole numbers between 10 and 1,000 ft3/s; and to 3 significant figures for more than 1,000 ft3/s. The number of significant figures used is based solely on the magnitude of the discharge value. The same rounding rules apply to discharges listed for partial-record stations and miscellaneous sites. 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. 23 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Arrangement of Records Water-quality records collected at a surface-water daily record station are published immediately following that record, regardless of the frequency of sample collection. Station number and name are the same for both records. Where a surface-water daily record station is not available or where the water quality differs significantly from that at the nearby surface-water station, the continuing water-quality record is published with its own station number and name in the regular downstream-order sequence. Water-quality data for partial-record stations and for miscellaneous sampling sites appear in separate tables following the table of discharge measurement at miscellaneous sites. On-site Measurements and Sample Collection In obtaining water-quality data, a major concern needs to be assuring that the data obtained represent the in situ quality of the water. To assure this, certain measurements, such as water temperature, pH, and dissolved oxygen, need to be made onsite when the samples are taken. To assure that measurements made in the laboratory also represent the in situ water, carefully prescribed procedures need to be followed in collecting the samples, in treating the samples to prevent changes in quality pending analysis, and in shipping the samples to the laboratory. Procedures for onsite measurements and for collecting, treating, and shipping samples are given in publications on "Techniques of Water- Resources Investigations," Book 1, Chap. D2; Book 3, Chap. C2; Book 5, Chap. A1, A3, and A4. Detailed information on collecting, treating, and shipping samples may be obtained from the Geological Survey District office. One sample can define adequately the water quality at a given time if the mixture of solutes throughout the stream cross section is homogeneous. However, the concentration of solutes at different locations in the cross section may vary widely with different rates of water discharge, depending on the source of material and the turbulence and mixing of the stream. Some streams must be sampled through several vertical sections to obtain a representative sample needed for an accurate mean concentration and for use in calculating load. All samples obtained for the National Stream Quality Accounting Network (see definitions) are obtained from at least several verticals. Whether samples are obtained from the centroid of flow or from several verticals, depends on flow conditions and other factors which must be evaluated by the collector. 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. 24 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Sediment Suspended-sediment concentrations are determined from samples collected by using depth-integrating and pumping sediment samplers. Samples usually are obtained at several verticals in the cross section, or a single sample may be obtained at a fixed point and a coefficient applied to determine the mean concentration in the cross sections. During periods of rapidly changing flow or rapidly changing concentration, samples may have been collected more frequently (twice daily or hourly). The published sediment discharges for days of rapidly changing flow or concentration were computed by the subdivided-day method (time-discharge weighted average). Therefore, for those days when the published sediment discharge value differs from the value computed as the product of discharge times mean concentration times 0.0027, the reader can assume that the sediment discharge for that day was computed by the subdivided-day method. For periods when no samples were collected, daily discharges of suspended sediment were estimated on the basis of water discharge, sediment concentrations observed immediately before and after the periods, suspended-sediment loads for other periods of similar discharge, and computed by the subdivided-day method using the transport curves. At other stations, suspended-sediment samples were collected periodically at many verticals in the stream cross section. Although data collected periodically may represent conditions only at the time of observations, such data are useful in establishing seasonal relations between quality and streamflow and in predicting long-term sediment- discharge characteristics of the stream. In addition to the records of suspended-sediment discharge, records of the periodic measurements of the particle- size distribution of the suspended sediment are included for some stations. Laboratory Measurements Sediment samples, samples for biochemical-oxygen demand (BOD), samples for indicator bacteria, and daily samples for specific conductance are analyzed locally. All other samples are analyzed in the Geological Survey laboratories in Denver, Co. or Ocala, Fla. Methods used in analyzing sediment samples and computing sediment records are given in TWRI, Book 5, Chap. C1. Methods used by the Geological Survey laboratories are given in TWRI, Book 1, Chap. D2; Book 3, Chap. C2; Book 5, Chap. A1, A3, and A4. 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. 25 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 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. 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 M Presence verified, not quantified 26 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Records of Ground-Water Levels Only ground-water level data from a basic network of observation wells are published herein. This basic network contains observation wells so located that the most significant data are obtained from the fewest wells in the most important aquifers. Data Collection and Computation Measurements of water levels are made in many types of wells under varying conditions, but the methods of measurement are standardized to the extent possible. The equipment and measuring techniques used at each observation well ensure that measurements at each well are of consistent accuracy and reliability. Each well is identified by means of (1) a 15-digit number that is based on latitude and longitude and (2) a local number that is provided for easy reference. See figure 10. Water-level records are obtained from direct measurements with a steel tape or from the graph or punched tape of a water-stage recorder. The water-level measurements in this report are given in feet with reference to land-surface datum (lsd). Land-surface datum is a datum plane that is approximately at land surface at each well. If known, the elevation of the land-surface datum is given in the well description. The height of the measuring point (MP) above or below land-surface datum is given in each well description. Water levels in wells equipped with recording gages are reported for every day and as an instantaneous observation at noon. Water levels are reported to as many significant figures as can be justified by the local conditions. For example, in a measurement of a depth to water of several hundred feet, the error of determining the absolute value of the total depth to water may be a few tenths of a foot, whereas the error in determining the net change of water level between successive measurements may be only a hundredth of a few hundredths of a foot. For lesser depths to water, the accuracy is greater. Accordingly, most measurements reported to a hundredth of a foot, but some are given to a tenth of a foot or a larger unit. Data Presentation Each well record consists of three parts, the station description, the data table of water levels observed during the water year and a graph of the water levels for the current water year and other selected period. The description of the well is presented first through use of descriptive headings preceding the tabular data. The comments to follow clarify information presented under the various headings of the well description. LOCATION.--This paragraph follows the well-identification number and reports the latitude and longitude (given in degrees, minutes, and seconds); a landline location designation; the hydrologic-unit number; the distance and direction from a geographic point of reference; and the owner's name. AQUIFER.--This entry designates by name (if a name exists) and geological age the aquifer(s) open to the well. WELL CHARACTERISTICS.--This entry describes the well in terms of depth, diameter, casing depth and/or screened interval, method of construction, use, and additional information such as casing breaks, collapsed screen, and other changes since construction. INSTRUMENTATION.--This paragraph provides information on both the frequency of measurement and the collection method used, allowing the user to better evaluate the reported water-level extremes by knowing whether they are based on weekly, monthly, or some other frequency of measurement. DATUM.--This entry describes both the measuring point and the land-surface elevation at the well. The measuring point is described physically (such as top of collar, notch in top of casing, plug in pump base and so on), and in relation to land surface (such as 1.3 ft above land-surface datum). The elevation of the land- surface datum is described in feet above (or below) sea level; it is reported with a precision depending on the method of determination. 27 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 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. 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. 28 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 ACCESS TO U.S. GEOLOGICAL SURVEY WATER DATA The U.S. Geological Survey provides near real-time stage and discharge data for many of the gaging stations equipped with the necessary telemetry and historic daily-mean and peak-flow discharge data for most current or discontinued gaging stations through the world wide web (WWW). These data may be accessed at http://water.usgs.gov Some water-quality and ground-water data also are available through the WWW. In addition, data can be provided in various machine-readable formats on magnetic tape or 3-1/2 inch floppy disk. Information about the availability of specific types of data or products, and user charges, can be obtained locally from each of the Water Resources Division District Offices (see address on the back of the title page). 29 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 DEFINITION OF TERMS Specialized technical terms related to streamflow, water-quality, and other hydrologic data, as used in this report, are defined below. Terms such as algae, water level, precipitation are used in their common everyday meanings, definitions of which are given in standard dictionaries. Not all terms defined in this alphabetical list apply to every State. See also table for converting English units to International System (SI) Units on the inside of the back cover. Acid neutralizing capacity (ANC) is the equivalent sum of all bases or base-producing materials, solutes plus particulates, in an aqueous system that can be titrated with acid to an equivalence point. This term designates titration of an “unfiltered” sample (formerly reported as alkalinity). Acre-foot (AC-FT, acre-ft) is a unit of volume, commonly used to measure quantities of water used or stored, equivalent to the volume of water required to cover 1 acre to a depth of 1 foot and equivalent to 43,560 cubic feet, 325,851 gallons, or 1,233 cubic meters. (See also “Annual runoff”) Adenosine triphosphate (ATP) is an organic, phosphate-rich, compound important in the transfer of energy in organisms. Its central role in living cells makes ATP an excellent indicator of the presence of living material in water. A measurement of ATP therefore provides a sensitive and rapid estimate of biomass. ATP is reported in micrograms per liter. Algal growth potential (AGP) is the maximum algal dry weight biomass that can be produced in a natural water sample under standardized laboratory conditions. The growth potential is the algal biomass present at stationary phase and is expressed as milligrams dry weight of algae produced per liter of sample. Alkalinity is the capacity of solutes in an aqueous system to neutralize acid. This term designates titration of a “filtered” sample. Annual runoff is the total quantity of water that is discharged (“runs off”) from a drainage basin in a year. Data reports may present annual runoff data as volumes in acre-feet, as discharges per unit of drainage area in cubic feet per second per square mile, or as depths of water on the drainage basin in inches. Annual 7-day minimum is the lowest mean value for any 7-consecutive-day period in a year. Annual 7-day minimum values are reported herein for the calendar year and the water year (October 1 to September 30). Most low-flow frequency analyses use a climatic year (April 1-March 31), which tends to prevent the low-flow period from being artificially split between adjacent years. 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.) Aroclor is the registered trademark for a group of polychlorinated biphenyls that were manufactured by the Monsanto Company prior to 1976. Aroclors are assigned specific 4-digit reference numbers dependent upon molecular type and degree of substitution of the biphenyl ring hydrogen atoms by chlorine atoms. The first two digits of a numbered aroclor represent the molecular type and the last two digits represent the weight percent of the hydrogen substituted chlorine. Artificial substrate is a device that is purposely placed in a stream or lake for colonization of organisms. The artificial substrate simplifies the community structure by standardizing the substrate from which each sample is taken. Examples of artificial substrates are basket samplers (made of wire cages filled with clean streamside rocks) and multiplate samplers (made of hardboard) for benthic organism collection, and plexiglass strips for periphyton collection. (See also “Substrate”) Ash mass is the mass or amount of residue present after the residue from the dry mass determination has been ashed in a muffle furnace at a temperature of 500 °C for 1 hour. Ash mass of zooplankton and phytoplankton is expressed in grams per cubic meter (g/m3), and periphyton and benthic organisms in grams per square meter (g/m2). (See also “Biomass”) Bacteria are microscopic unicellular organisims, 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. 30 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Base discharge (for peak discharge) is a discharge value, determined for selected stations, above which peak discharge data are published. The base discharge at each station is selected so that an average of about three peaks per year will be published. Base flow is sustained flow of a stream in the absence of direct runoff. It includes natural and human-induced streamflows. Natural base flow is sustained largely by ground-water discharge. Bedload is material in transport that is supported primarily by the streambed. In this report, bedload is considered to consist of particles in transit from the bed to an elevation equal to the top of the bedload sampler nozzle (ranging from 0.25 to 0.5 ft) that are retained in the bedload sampler. A sample collected with a pressure-differential bedload sampler may also contain a component of the suspended load. Bedload discharge (tons per day) is rate of sediment moving as bedload, reported as dry weight, that passes through a cross section in a given time. NOTE: Bedload discharge values in this report may include a component of the suspended-sediment discharge. A correction may be necessary when computing the total sediment discharge by summing the bedload discharge and the suspended-sediment discharge. (See also “Bedload” and “Sediment”) Bed material is the sediment mixture of which a streambed, lake, pond, reservoir, or estuary bottom is composed. (See also “Bedload” and “Sediment”) Benthic organisms are the group of organisms inhabiting the bottom of an aquatic environment. They include a number of types of organisms, such as bacteria, fungi, insect larvae and nymphs, snails, clams, and crayfish. They are useful as indicators of water quality. Biochemical oxygen demand (BOD) is a measure of the quantity of dissolved oxygen, in milligrams per liter, necessary for the decomposition of organic matter by microorganisms, such as bacteria. Biomass is the amount of living matter present at any given time, expressed as mass per unit area or volume of habitat. Biomass pigment ratio is an indicator of the total proportion of periphyton which are autotrophic (plants). This is also called the Autotrophic Index. Blue-green algae (Cyanophyta) are a group of phytoplankton organisms having a blue pigment, in addition to the green pigment called chlorophyll. Blue-green algae often cause nuisance conditions in water. Concentrations are expressed as a number of cells per milliliter (cells/mL) of sample. (See also “Phytoplankton”) Bottom material (See “Bed material”) Cells/volume refers to the number of cells of any organism that 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 volume, and are generally reported as cells or units per milliliter (mL) or liter (L). Cells volume (biovolume) determination is one of several common methods used to estimate biomass of algae in aquatic systems. Cell members of algae are frequently used in aquatic surveys as an indicator of algal production. However, cell numbers alone cannot represent true biomass because of considerable cell-size variation among the algal species. Cell volume (µm3) is determined by obtaining critical cell measurements on cell dimensions (for example, length, width, height, or radius) for 20 to 50 cells of each important species to obtain an average biovolume per cell. Cells are categorized according to the correspondence of their cellular shape to the nearest geometric solid or combinations of simple solids (for example, spheres, cones, or cylinders). Representative formulae used to compute biovolume are as follows: sphere 4/3 πr3 cone 1/3 πr3h cylinder πr3h. pi is the ratio of the circumference to the diameter of a circle; pi = 3.14159… From cell volume, total algal biomass expressed as biovolume (µm3/mL) is thus determined by multiplying the number of cells of a given species by its average cell volume and then summing these volumes over all species. Cfs-day (See “Cubic foot per second-day”) 31 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Chemical oxygen demand (COD) is a measure of the chemically oxidizable material in the water and furnishes an approximation of the amount of organic and reducing material present. The determined value may correlate with BOD or with carbonaceous organic pollution from sewage or industrial wastes. [See also “Biochemical oxygen demand (BOD)”] Clostridium perfringens (C. perfringens) is a spore-forming bacterium that is common in the feces of human and other warm-blooded animals. Clostridial spores are being used experimentally as an indicator of past fecal contamination and presence of microorganisms that are resistant to disinfection and environmental stresses. (See also “Bacteria”) Coliphages are viruses that infect and replicate in coliform bacteria. They are indicative of sewage contamination of waters and of the survival and transport of viruses in the environment. Color unit is produced by 1 milligram per liter of platinum in the form of the chloroplatinate ion. Color is expressed in units of the platinum-cobalt scale. Confined aquifer is a term used to describe an aquifer containing water between two relatively impermeable boundaries. The water level in a well tapping a confined aquifer stands above the top of the confined aquifer and can be higher or lower than the water table that may be present in the material above it. In some cases, the water level can rise above the ground surface, yielding a flowing well. Contents is the volume of water in a reservoir or lake. Unless otherwise indicated, volume is computed on the basis of a level pool and does not include bank storage. Continuous-record station is a site where data are collected with sufficient frequency to define daily mean values and variations within a day. Control designates a feature in the channel downstream from a gaging station that physically influences the water- surface elevation and thereby determines the stage-discharge relation at the gage. This feature may be a constriction of the channel, a bedrock outcrop, a gravel bar, an artificial structure, or a uniform cross section over a long reach of the channel. Control structure as used in this report is a structure on a stream or canal that is used to regulate the flow or stage of the stream or to prevent the intrusion of saltwater. Cubic foot per second (CFS, ft3/s) is the rate of discharge representing a volume of 1 cubic foot passing a given point in 1 second. It is equivalent to approximately 7.48 gallons per second or approximately 449 gallons per minute, or 0.02832 cubic meters per second. The term “second-feet” sometimes is used synonymously with “cubic feet per second” but is now obsolete. Cubic foot per second-day (CFS-DAY, Cfs-day, [(ft3/s)/d]) is the volume of water represented by a flow of 1 cubic foot per second for 24 hours. It is equivalent to 86,400 cubic feet, 1.98347 acre-feet, 646,317 gallons, or 2,446.6 cubic meters. The daily-mean discharges reported in the daily-value data tables are numerically equal to the daily volumes in cfs-days, and the totals also represent volumes in cfs-days. Cubic foot per second per square mile [CFSM, (ft3/s)/mi2] is the average number of cubic feet of water flowing per second from each square mile of area drained, assuming the runoff is distributed uniformly in time and area. (See also “Annual runoff”) Daily mean suspended-sediment concentration is the time-weighted concentration of suspended sediment passing a stream cross section during a 24-hour day. (See also “Mean concentration of suspended sediment,” “Sediment,” and “Suspended-sediment concentration”) Daily-record station is a site where data are collected with sufficient frequency to develop a record of one or more data values per day. The frequency of data collection can range from continuous recording to periodic sample or data collection on a daily or near-daily basis. Data Collection Platform (DCP) is an electronic instrument that collects, processes, and stores data from various sensors, and transmits the data by satellite data relay, line-of-sight radio, and/or landline telemetry. Data logger is a microprocessor-based data acquisition system designed specifically to acquire, process, and store data. Data are usually downloaded from onsite data loggers for entry into office data systems. 32 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Datum is a surface or point relative to which measurements of height and/or horizontal position are reported. A vertical datum is a horizontal surface used as the zero point for measurements of gage height, stage, or elevation; a horizontal datum is a reference for positions given in terms of latitude-longitude, State Plane coordinates, or UTM coordinates. (See also “Gage datum,” “Land-surface datum,” “National Geodetic Vertical Datum of 1929,” and “North American Vertical Datum of 1988”) Diatoms are the unicellular or colonial algae having a siliceous shell. Their concentrations are expressed as number of cells per milliliter (cells/mL) of sample. (See also “Phytoplankton”) Diel is of or pertaining to a 24-hour period of time; a regular daily cycle. Discharge, or flow, is the rate that matter passes through a cross section of a stream channel or other water body per unit of time. The term commonly refers to the volume of water (including, unless otherwise stated, any sediments or other constituents suspended or dissolved in the water) that passes a cross section in a stream channel, canal, pipeline, etc., within a given period of time (cubic feet per second). Discharge also can apply to the rate at which constituents such as suspended sediment, bedload, and dissolved or suspended chemical constituents, pass through a cross section, in which cases the quantity is expressed as the mass of constituent that passes the cross section in a given period of time (tons per day). Dissolved refers to that material in a representative water sample that passes through a 0.45-micrometer membrane filter. This is a convenient operational definition used by Federal and State agencies that collect water-quality data. Determinations of “dissolved” constituent concentrations are made on sample water that has been filtered. Dissolved oxygen (DO) is the molecular oxygen (oxygen gas) dissolved in water. The concentration in water is a function of atmospheric pressure, temperature, and dissolved-solids concentration of the water. The ability of water to retain oxygen decreases with increasing temperature or dissolved-solids concentration. Photosynthesis and respiration by plants commonly cause diurnal variations in dissolved-oxygen concentration in water from some streams. Dissolved-solids concentration in water is the quantity of dissolved material in a sample of water. It 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, the bicarbonate (generally a major dissolved component of water) is converted to carbonate. In the mathematical calculation, the bicarbonate value, in milligrams per liter, is multiplied by 0.4926 to convert it to carbonate. Alternatively, alkalinity concentration (as mg/L CaCO3) can be converted to carbonate concentration by multiplying by 0.60. Diversity index (H) (Shannon Index) is a numerical expression of evenness of distribution of aquatic organisms. The formula for diversity index is: where ni is the number of individuals per taxon, n is the total number of individuals, and s is the total number of taxa in the sample of the community. 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 specific location is that area upstream from the location, measured in a horizontal plane, that has a common outlet at the site for its surface runoff from precipitation that normally drains by gravity into a stream. Drainage areas given herein include all closed basins, or noncontributing areas, within the area unless otherwise specified. Drainage basin is a part of the Earth’s surface that contains a drainage system with a common outlet for its surface runoff. (See “Drainage area”) Dry mass refers to the mass of residue present after drying in an oven at 105 °C, 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. (See also “Ash mass,” “Biomass,” and “Wet mass”) d ni n--- lo g 2 ni n--- i 1 ≈ s ∑ – = 33 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Dry weight refers to the weight of animal tissue after it has been dried in an oven at 65 °C until a constant weight is achieved. Dry weight represents total organic and inorganic matter in the tissue. (See also “Wet weight”) Enterococcus bacteria are commonly found in the feces of humans and other warm-blooded animals. Although some strains are ubiquitous and not related to fecal pollution, the presence of enterococci in water is an indication of fecal pollution and the possible presence of enteric pathogens. Enterococcus bacteria are those bacteria that produce pink to red colonies with black or reddish-brown precipitate after incubation at 41 °C on mE agar and subsequent transfer to EIA medium. Enterococci include Streptococcus feacalis, Streptococcus feacium, Streptococcus avium, and their variants. (See also “Bacteria”) EPT Index is the total number of distinct taxa within the insect orders Ephemeroptera, Plecoptera, and Trichoptera. This index summarizes the taxa richness within the aquatic insects that are generally considered pollution sensitive, the index usually decreases with pollution. Escherichia coli (E. coli) are bacteria present in the intestine and feces of warm-blooded animals. E. coli are a member species of the fecal coliform group of indicator bacteria. In the laboratory, they are defined as those bacteria that produce yellow or yellow-brown colonies on a filter pad saturated with urea substrate broth after primary culturing for 22 to 24 hours at 44.5 °C on mTEC medium. Their concentrations are expressed as number of colonies per 100 mL of sample. (See also “Bacteria”) Estimated (E) value of a concentration is reported when an analyte is detected and all criteria for a positive result are met. If the concentration is less than the method detection limit (MDL), an ‘E’ code will be reported with the value. If the analyte is qualitatively identified as present, but the quantitative determination is substantially more uncertain, the National Water Quality Laboratory will identify the result with an ‘E’ code even though the measured value is greater than the MDL. A value reported with an ‘E’ code should be used with caution. When no analyte is detected in a sample, the default reporting value is the MDL preceded by a less than sign (<). Euglenoids (Euglenophyta) are a group of algae that are usually free-swimming and rarely creeping. They have the ability to grow either photosynthetically in the light or heterotrophically in the dark. (See also “Phytoplankton”) Extractable organic halides (EOX) are organic compounds that contain halogen atoms such as chlorine. These organic compounds are semi-volatile and extractable by ethyl acetate from air-dried streambed sediments. The ethyl acetate extract is combusted, and the concentration is determined by microcoulometric determination of the halides formed. The concentration is reported as micrograms of chlorine per gram of the dry weight of the streambed sediments. Fecal coliform bacteria are present in the intestine or feces of warm-blooded animals. They are often used as indicators of the sanitary quality of the water. In the laboratory, they are defined as all organisms that produce blue colonies within 24 hours when incubated at 44.5 °C plus or minus 0.2 °C on M-FC medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. (See also “Bacteria”) Fecal streptococcal bacteria are present in the intestine of warm-blooded animals and are ubiquitous in the environment. They are characterized as gram-positive, cocci bacteria that are capable of growth in brain-heart infusion broth. In the laboratory, they are defined as all the organisms that produce red or pink colonies within 48 hours at 35 °C plus or minus 1.0 °C on KF-streptococcus medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. (See also “Bacteria”) Fire algae (Pyrrhophyta) are free-swimming unicells characterized by a red pigment spot. (See also “Phytoplankton”) Flow-duration percentiles are values on a scale of 100 that indicate the percentage of time for which a flow is not exceeded. For example, the 90th percentile of river flow is greater than or equal to 90 percent of all recorded flow rates. 34 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Gage datum is a horizontal surface used as a zero point for measurement of stage or gage height. This surface usually is located slightly below the lowest point of the stream bottom such that the gage height is usually slightly larger than the maximum depth of water. Because the gage datum itself is not an actual physical object, the datum usually is defined by specifying the elevations of permanent reference marks such as bridge abutments and survey monuments, and the gage is set to agree with the reference marks. Gage datum is a local datum that is maintained independently of any National geodetic datum. However, if the elevation of the gage datum relative to the National datum (North American Vertical Datum of 1988 or National Geodetic Vertical Datum of 1929) has been determined, then the gage readings can be converted to elevations above the National datum by adding the elevation of the gage datum to the gage reading. Gage height (G.H.) is the water-surface elevation, in feet above the gage datum. If the water surface is below the gage datum, the gage height is negative. Gage height is often used interchangeably with the more general term “stage,” although gage height is more appropriate when used in reference to a reading on a gage. Gage values are values that are recorded, transmitted and/or computed from a gaging station. Gage values typically are collected at 5-, 15-, or 30-minute intervals. Gaging station is a site on a stream, canal, lake, or reservoir where systematic observations of stage, discharge, or other hydrologic data are obtained. When used in connection with a discharge record, the term is applied only to those gaging stations where a continuous record of discharge is computed. Gas chromatography/flame ionization detector (GC/FID) is a laboratory analytical method used as a screening technique for semivolatile organic compounds that are extractable from water in methylene chloride. 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. (See also “Phytoplankton”) Habitat quality index is the qualitative description (level 1) of instream habitat and riparian conditions surrounding the reach sampled. Scores range from 0 to 100 percent with higher scores indicative of desirable habitat conditions for aquatic life. Index only applicable to wadable streams. Hardness of water is a physical-chemical characteristic that is commonly recognized by the increased quantity of soap required to produce lather. It is computed as the sum of equivalents of polyvalent cations (primarily calcium and magnesium) and is expressed as the equivalent concentration of calcium carbonate (CaCO3). High tide is the maximum height reached by each rising tide. The high-high and low-high tides are the higher and lower of the two high tides, respectively, of each tidal day. See NOAA web site: http://www.co-ops.nos.noaa.gov/tideglos.html Hilsenhoff’s Biotic Index (HBI) is an indicator of organic pollution which uses tolerance values to weight taxa abundances; usually increases with pollution. It is calculated as follows: where n is the number of individuals of each taxon, a is the tolerance value of each taxon, and N is the total number of organisms in the sample. Horizontal datum (See “Datum”) Hydrologic benchmark station is one that provides hydrologic data for a basin in which the hydrologic regimen will likely be governed solely by natural conditions. Data collected at a benchmark station may be used to separate effects of natural from human-induced changes in other basins that have been developed and in which the physiography, climate, and geology are similar to those in the undeveloped benchmark basin. Hydrologic index stations referred to in this report are four continuous-record gaging stations that have been selected as representative of streamflow patterns for their respective regions. Station locations are shown on index maps. HBI sum n ( ) a ( ) N = 35 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Hydrologic unit is a geographic area representing part or all of a surface drainage basin or distinct hydrologic feature as defined by the former Office of Water Data Coordination and delineated on the State Hydrologic Unit Maps by the USGS. Each hydrologic unit is identified by an 8-digit number. Inch (IN., in.), as used in this report, refers to the depth to which the drainage area would be covered with water if all of the runoff for a given time period were uniformly distributed on it. (See also “Annual runoff”) Instantaneous discharge is the discharge at a particular instant of time. (See also “Discharge”) Laboratory Reporting Level (LRL) is generally equal to twice the yearly determined long-term method detection level (LT-MDL). The LRL controls false negative error. The probability of falsely reporting a non-detection for a sample that contained an analyte at a concentration equal to or greater than the LRL is predicted to be less than or equal to 1 percent. The value of the LRL will be reported with a “less than” (<) remark code for samples in which the analyte was not detected. The National Water Quality Laboratory collects quality-control data from selected analytical methods on a continuing basis to determine LT-MDLs and to establish LRLs. These values are reevaluated annually based on the most current quality-control data and may, therefore, change. [Note: In several previous NWQL documents (Connor and others, 1998; NWQL Technical Memorandum 98.07, 1998), the LRL was called the non-detection value or NDV—a term that is no longer used.) Land-surface datum (lsd) is a datum plane that is approximately at land surface at each ground-water observation well. Light-attenuation coefficient, also known as the extinction coefficient, is a measure of water clarity. Light is attenuated according to the Lambert-Beer equation , where Io is the source light intensity, I is the light intensity at length L (in meters) from the source, λ is the light- attenuation coefficient, and e is the base of the natural logarithm. The light attenuation coefficient is defined as . Lipid is any one of a family of compounds that are insoluble in water and that make up one of the principal components of living cells. Lipids include fats, oils, waxes, and steroids. Many environmental contaminants such as organochlorine pesticides are lipophilic. Long-Term Method Detection Level (LT–MDL) is a detection level derived by determining the standard deviation of a minimum of 24 method detection limit (MDL) spike sample measurements over an extended period of time. LT–MDL data are collected on a continuous basis to assess year-to-year variations in the LT–MDL. The LT–MDL controls false positive error. The chance of falsely reporting a concentration at or greater than the LT–MDL for a sample that did not contain the analyte is predicted to be less than or equal to 1 percent. Low tide is the minimum height reached by each falling tide. The high-low and low-low tides are the higher and lower of the two low tides, respectively, of each tidal day. See NOAA web site: http://www.co-ops.nos.noaa.gov/ tideglos.html Macrophytes are the macroscopic plants in the aquatic environment. The most common macrophytes are the rooted vascular plants that are usually arranged in zones in aquatic ecosystems and restricted in the area by the extent of illumination through the water and sediment deposition along the shoreline. Mean concentration of suspended sediment (Daily mean suspended-sediment concentration) is the time-weighted concentration of suspended sediment passing a stream cross section during a given time period. (See also “Daily mean suspended-sediment concentration” and “Suspended-sediment concentration”) Mean discharge (MEAN) is the arithmetic mean of individual daily mean discharges during a specific period. (See also “Discharge”) Mean high or low tide is the average of all high or low tides, respectively, over a specific period. I Ioe λL – = λ 1 L--lo g e I Io --- – = 36 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Mean sea level is a local tidal datum. It is the arithmetic mean of hourly heights observed over the National Tidal Datum Epoch. Shorter series are specified in the name; for example, monthly mean sea level and yearly mean sea level. In order that they may be recovered when needed, such datums are referenced to fixed points known as benchmarks. (See also “Datum”) Measuring point (MP) is an arbitrary permanent reference point from which the distance to water surface in a well is measured to obtain water level. Membrane filter is a thin microporous material of specific pore size used to filter bacteria, algae, and other very small particles from water. Metamorphic stage refers to the stage of development that an organism exhibits during its transformation from an immature form to an adult form. This developmental process exists for most insects, and the degree of difference from the immature stage to the adult form varies from relatively slight to pronounced, with many intermediates. Examples of metamorphic stages of insects are egg-larva-adult or egg-nymph-adult. Method Detection Limit (MDL) is the minimum concentration of a substance that can be measured and reported with 99-percent confidence that the analyte concentration is greater than zero. It is determined from the analysis of a sample in a given matrix containing the analyte. At the MDL concentration, the risk of a false positive is predicted to be less than or equal to 1 percent. Methylene blue active substances (MBAS) are apparent detergents. The determination depends on the formation of a blue color when methylene blue dye reacts with synthetic anionic detergent compounds. Micrograms per gram (UG/G, µg/g) is a unit expressing the concentration of a chemical constituent as the mass (micrograms) of the element per unit mass (gram) of material analyzed. Micrograms per kilogram (UG/KG, µg/kg) is a unit expressing the concentration of a chemical constituent as the mass (micrograms) of the constituent per unit mass (kilogram) of the material analyzed. One microgram per kilogram is equivalent to 1 part per billion. Micrograms per liter (UG/L, µg/L) is a unit expressing the concentration of chemical constituents in water as mass (micrograms) of constituent per unit volume (liter) of water. One thousand micrograms per liter is equivalent to 1 milligram per liter. One microgram per liter is equivalent to 1 part per billion. Microsiemens per centimeter (US/CM, µS/cm) is a unit expressing the amount of electrical conductivity of a solution as measured between opposite faces of a centimeter cube of solution at a specified temperature. Siemens is the International System of Units nomenclature. It is synonymous with mhos and is the reciprocal of resistance in ohms. Milligrams per liter (MG/L, mg/L) is a unit for expressing the concentration of chemical constituents in water as the mass (milligrams) of constituent per unit volume (liter) of water. Concentration of suspended sediment also is expressed in mg/L and is based on the mass of dry sediment per liter of water-sediment mixture. Minimum Reporting Level (MRL) is the smallest measured concentration of a constituent that may be reliably reported by using a given analytical method (Timme, 1995). Miscellaneous site, miscellaneous station, or miscellaneous sampling site is a site where streamflow, sediment, and/ or water-quality data or water-quality or sediment samples are collected once, or more often on a random or discontinuous basis to provide better areal coverage for defining hydrologic and water-quality conditions over a broad area in a river basin. Most probable number (MPN) is an index of the number of coliform bacteria that, more probably than any other number, would give the results shown by the laboratory examination; it is not an actual enumeration. MPN is determined from the distribution of gas-positive cultures among multiple inoculated tubes. Multiple-plate samplers are artificial substrates of known surface area used for obtaining benthic invertebrate samples. They consist of a series of spaced, hardboard plates on an eyebolt. Nanograms per liter (NG/L, ng/L) is a unit expressing the concentration of chemical constituents in solution as mass (nanograms) of solute per unit volume (liter) of water. One million nanograms per liter is equivalent to 1 milligram per liter. 37 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 National Geodetic Vertical Datum of 1929 (NGVD of 1929) is a fixed reference adopted as a standard geodetic datum for elevations determined by leveling. It was formerly called “Sea Level Datum of 1929” or “mean sea level.” Although the datum was derived from the mean sea level at 26 tide stations, it does not necessarily represent local mean sea level at any particular place. See NOAA web site: http://www.ngs.noaa.gov/ faq.shtml#WhatVD29VD88 (See “North American Vertical Datum of 1988”) Natural substrate refers to any naturally occurring immersed or submersed solid surface, such as a rock or tree, upon which an organism lives. (See also “Substrate”) Nekton are the consumers in the aquatic environment and consist of large free-swimming organisms that are capable of sustained, directed mobility. Nephelometric turbidity unit (NTU) is the measurement for reporting turbidity that is based on use of a standard suspension of Formazin. Turbidity measured in NTU uses nephelometric methods that depend on passing specific light of a specific wavelength through the sample. North American Vertical Datum of 1988 (NAVD 1988) is a fixed reference adopted as the official civilian vertical datum for elevations determined by Federal surveying and mapping activities in the U.S. This datum was established in 1991 by minimum-constraint adjustment of the Canadian, Mexican, and U.S. first-order terrestrial leveling networks. Open or screened interval is the length of unscreened opening or of well screen through which water enters a well, in feet below land surface. Organic carbon (OC) is a measure of organic matter present in aqueous solution, suspension, or bottom sediments. May be reported as dissolved organic carbon (DOC), particulate organic carbon (POC), or total organic carbon (TOC). Organic mass or volatile mass of the living substance is the difference between the dry mass and ash mass and represents the actual mass of the living matter. Organic mass is expressed in the same units as for ash mass and dry mass. (See also “Ash mass,” “Biomass,” and “Dry mass”) Organism count/area refers to the number of organisms collected and enumerated in a sample and adjusted to the number per area habitat, usually square meter (m2), acre, or hectare. Periphyton, benthic organisms, and macrophytes are expressed in these terms. Organism count/volume refers to the number of organisms collected and enumerated in a sample and adjusted to the number per sample volume, usually milliliter (mL) or liter (L). Numbers of planktonic organisms can be expressed in these terms. Organochlorine compounds are any chemicals that contain carbon and chlorine. Organochlorine compounds that are important in investigations of water, sediment, and biological quality include certain pesticides and industrial compounds. Parameter Code is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property. Partial-record station is a site where discrete measurements of one or more hydrologic parameters are obtained over a period of time without continuous data being recorded or computed. A common example is a crest-stage gage partial-record station at which only peak stages and flows are recorded. Particle size is the diameter, in millimeters (mm), of a particle determined by sieve or sedimentation methods. The sedimentation method utilizes the principle of Stokes Law to calculate sediment particle sizes. Sedimentation methods (pipet, bottom-withdrawal tube, visual-accumulation tube, Sedigraph) determine fall diameter of particles in either distilled water (chemically dispersed) or in native water (the river water at the time and point of sampling). 38 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Particle-size classification, as used in this report, agrees with the recommendation 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 0.004 - 0.062 Sedimentation Sand 0.062 - 2.0 Sedimentation/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. Peak flow (peak stage) is an instantaneous local maximum value in the continuous time series of streamflows or stages, preceded by a period of increasing values and followed by a period of decreasing values. Several peak values ordinarily occur in a year. The maximum peak value in a year is called the annual peak; peaks lower than the annual peak are called secondary peaks. Occasionally, the annual peak may not be the maximum value for the year; in such cases, the maximum value occurs at midnight at the beginning or end of the year, on the recession from or rise toward a higher peak in the adjoining year. If values are recorded at a discrete series of times, the peak recorded value may be taken as an approximation to the true peak, which may occur between the recording instants. If the values are recorded with finite precision, a sequence of equal recorded values may occur at the peak; in this case, the first value is taken as the peak. Percent composition or percent of total is a unit for expressing the ratio of a particular part of a sample or population to the total sample or population, in terms of types, numbers, weight, mass, or volume. Percent shading is determined by using a clinometer to estimate left and right bank shading. The values are added together and divided by 180 to determine percent shading relative to a horizontal surface. Periodic-record station is a site where stage, discharge, sediment, chemical, physical, or other hydrologic measurements are made one or more times during a year, but at a frequency insufficient to develop a daily record. Periphyton is the assemblage of microorganisms attached to and living upon submerged solid surfaces. While primarily consisting of algae, they also include bacteria, fungi, protozoa, rotifers, and other small organisms. Periphyton are useful indicators of water quality. Pesticides are chemical compounds used to control undesirable organisms. Major categories of pesticides include insecticides, miticides, fungicides, herbicides, and rodenticides. pH of water is the negative logarithm of the hydrogen-ion activity. Solutions with pH less than 7 are termed “acidic,” and solutions with a pH greater than 7 are termed “basic.” Solutions with a pH of 7 are neutral. The presence and concentration of many dissolved chemical constituents found in water are, in part, influenced by the hydrogen- ion activity of water. Biological processes including growth, distribution of organisms, and toxicity of the water to organisms are also influenced, in part, by the hydrogen-ion activity of water. 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. (See also “Plankton”) Picocurie (PC, pCi) is one trillionth (1 x 10-12) of the amount of radioactive nuclide represented by a curie (Ci). A curie is the quantity of radioactive nuclide that yields 3.7 x 1010 radioactive disintegrations per second (dps). A picocurie yields 0.037 dps, or 2.22 dpm (disintegrations per minute). Plankton is the community of suspended, floating, or weakly swimming organisms that live in the open water of lakes and rivers. Concentrations are expressed as a number of cells per milliliter (cells/mL of sample). 39 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 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. Polychlorinated naphthalenes (PCNs) are industrial chemicals that are mixtures of chlorinated naphthalene compounds. They have properties and applications similar to polychlorinated biphenyls (PCBs) and have been identified in commercial PCB preparations. Primary productivity is a measure of the rate at which new organic matter is formed and accumulated through photosynthetic and chemosynthetic activity of producer organisms (chiefly, green plants). The rate of primary production is estimated by measuring the amount of oxygen released (oxygen method) or the amount of carbon assimilated (carbon method) by the plants. Primary productivity (carbon method) is expressed as milligrams of carbon per area per unit time [mg C/(m2/time)] for periphyton and macrophytes or per volume [mg C/(m3/time)] for phytoplankton. Carbon method defines the amount of carbon dioxide consumed as measured by radioactive carbon (carbon-14). The carbon-14 method is of greater sensitivity than the oxygen light and dark bottle method and is preferred for use in unenriched waters. Unit time may be either the hour or day, depending on the incubation period. (See also “Primary productivity”) Primary productivity (oxygen method) is expressed as milligrams of oxygen per area per unit time [mg O/(m2/ time)] for periphyton and macrophytes or per volume [mg O/(m3/time)] for phytoplankton. Oxygen method defines production and respiration rates as estimated from changes in the measured dissolved-oxygen concentration. The oxygen light and dark bottle method is preferred if the rate of primary production is sufficient for accurate measurements to be made within 24 hours. Unit time may be either the hour or day, depending on the incubation period. (See also “Primary productivity”) Radioisotopes are isotopic forms of an element that exhibit radioactivity. Isotopes are varieties of a chemical element that differ in atomic weight, but are very nearly alike in chemical properties. The difference arises because the atoms of the isotopic forms of an element differ in the number of neutrons in the nucleus; for example, ordinary chlorine is a mixture of isotopes having atomic weights of 35 and 37, and the natural mixture has an atomic weight of about 35.453. Many of the elements similarly exist as mixtures of isotopes, and a great many new isotopes have been produced in the operation of nuclear devices such as the cyclotron. There are 275 isotopes of the 81 stable elements, in addition to more than 800 radioactive isotopes. Recoverable from bed (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. (See also “Bed material”) Recurrence interval, also referred to as return period, is the average time, usually expressed in years, between occurrences of hydrologic events of a specified type (such as exceedances of a specified high flow or non- exceedance of a specified low flow). The terms “return period” and “recurrence interval” do not imply regular cyclic occurrence. The actual times between occurrences vary randomly, with most of the times being less than the average and a few being substantially greater than the average. For example, the 100-year flood is the flow rate that is exceeded by the annual maximum peak flow at intervals whose average length is 100 years (that is, once in 100 years, on average); almost two-thirds of all exceedances of the 100-year flood occur less than 100 years after the previous exceedance, half occur less than 70 years after the previous exceedance, and about one- eighth occur more than 200 years after the previous exceedance. Similarly, the 7-day 10-year low flow (7Q10) is the flow rate below which the annual minimum 7-day-mean flow dips at intervals whose average length is 10 years (that is, once in 10 years, on average); almost two-thirds of the non-exceedances of the 7Q10 occur less than 10 years after the previous non-exceedance, half occur less than 7 years after, and about one-eighth occur more than 20 years after the previous non-exceedance. The recurrence interval for annual events is the reciprocal of the annual probability of occurrence. Thus, the 100-year flood has a 1-percent chance of being exceeded by the maximum peak flow in any year, and there is a 10-percent chance in any year that the annual minimum 7-day- mean flow will be less than the 7Q10. 40 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Replicate samples are a group of samples collected in a manner such that the samples are thought to be essentially identical in composition. Return period (See “Recurrence interval”) River mileage is the curvilinear distance, in miles, measured upstream from the mouth along the meandering path of a stream channel in accordance with Bulletin No. 14 (October 1968) of the Water Resources Council, and typically used to denote location along a river. Runoff is the quantity of water that is discharged (“runs off”) from a drainage basin in a given time period. Runoff data may be presented as volumes in acre-feet, as mean discharges per unit of drainage area in cubic feet per second per square mile, or as depths of water on the drainage basin in inches. (See also “Annual runoff”) Sea level, as used in this report, refers to one of the two commonly used national vertical datums, (NGVD 1929 or NAVD 1988). See separate entries for definitions of these datums. See conversion of units page (inside back cover) for identification of the datum used in this report. Sediment is solid material that originates mostly from disintegrated rocks; when transported by, suspended in, or deposited from water, it is referred to as “fluvial sediment.” Sediment 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 and land-use factors. Some major factors are topography, soil characteristics, land cover, and depth and intensity of precipitation. Seven-day 10-year low flow (7Q10) is the discharge below which the annual 7-day minimum flow falls in 1 year out of 10 on the long-run average. The recurrence interval of the 7Q10 is 10 years; the chance that the annual 7-day minimum flow will be less than the 7Q10 is 10 percent in any given year. (See also “Recurrence interval” and “Annual 7-day minimum”) 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. Sodium hazard in water is an index that can be used to evaluate the suitability of water for irrigating crops. Specific electrical conductance (conductivity) is a measure of the capacity of water (or other media) to conduct an electrical current. It is expressed in microsiemens per centimeter at 25 °C. Specific electrical conductance is a function of the types and quantity of dissolved substances in water and can be used for approximating the dissolved-solids content of the water. Commonly, the concentration of dissolved solids (in milligrams per liter) is from 55 to 75 percent of the specific conductance (in microsiemens). This relation is not constant from stream to stream, and it may vary in the same source with changes in the composition of the water. Stable isotope ratio (per MIL/MIL) is a unit expressing the ratio of the abundance of two radioactive isotopes. Isotope ratios are used in hydrologic studies to determine the age or source of specific waters, to evaluate mixing of different waters, as an aid in determining reaction rates, and other chemical or hydrologic processes. Stage (See “Gage height”) Stage-discharge relation is the relation between the water-surface elevation, termed stage (gage height), and the volume of water flowing in a channel per unit time. Streamflow is the discharge that occurs in a natural channel. Although the term “discharge” can be applied to the flow of a canal, the word “streamflow” uniquely describes the discharge in a surface stream course. The term “streamflow” is more general than “runoff” as streamflow may be applied to discharge whether or not it is affected by diversion or regulation. Substrate is the physical surface upon which an organism lives. 41 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Substrate Embeddedness Class is a visual estimate of riffle streambed substrate larger than gravel that is surrounded or covered by fine sediment (<2mm, sand or finer). Below are the class categories expressed as percent covered by fine sediment: 0 < no gravel or larger substrate 1 > 75% 2 51-75% 4 5-25% 3 26-50% 5 < 5% Surface area of a lake is that area (acres) encompassed by the boundary of the lake as shown on USGS topographic maps, or other available maps or photographs. Because surface area changes with lake stage, surface areas listed in this report represent those determined for the stage at the time the maps or photographs were obtained. Surficial bed material is the upper surface (0.1 to 0.2 ft) of the bed material such as that material which is sampled using U.S. Series Bed-Material Samplers. Suspended (as used in tables of chemical analyses) refers to the amount (concentration) of undissolved material in a water-sediment mixture. It is operationally defined as the material retained on a 0.45-micrometer filter. Suspended, recoverable is the amount of a given constituent that is in solution after the part of a representative suspended water-sediment sample that is retained on a 0.45-micrometer membrane filter has been digested by a method (usually using a dilute acid solution) that results in dissolution of only readily soluble substances. Complete dissolution of all the particulate matter is not achieved by the digestion treatment and thus the determination represents something less than the “total” amount (that is, less than 95 percent) of the constituent present in the sample. To achieve comparability of analytical data, equivalent digestion procedures are required of all laboratories performing such analyses because different digestion procedures are likely to produce different analytical results. Determinations of “suspended, recoverable” constituents are made either by directly analyzing the suspended material collected on the filter or, more commonly, by difference, based on determinations of (1) dissolved and (2) total recoverable concentrations of the constituent. (See also “Suspended”) Suspended sediment is the sediment maintained in suspension by the upward components of turbulent currents or that exists in suspension as a colloid. (See also “Sediment”) Suspended-sediment concentration is the velocity-weighted concentration of suspended sediment in the sampled zone (from the water surface to a point approximately 0.3 ft above the bed) expressed as milligrams of dry sediment per liter of water-sediment mixture (mg/L). The analytical technique uses the mass of all of the sediment and the net weight of the water-sediment mixture in a sample to compute the suspended-sediment concentration. (See also “Sediment” and “Suspended sediment”) Suspended-sediment discharge (tons/day) is the rate of sediment transport, as measured by dry mass or volume, that passes a cross section in a given time. It is calculated in units of tons per day as follows: concentration (mg/L) x discharge (ft3/s) x 0.0027. (See also “Sediment,” “Suspended sediment,” and “Suspended-sediment concentration”) Suspended-sediment load is a general term that refers to a given characteristic of the material in suspension that passes a point during a specified period of time. The term needs to be qualified, such as “annual suspended- sediment load” or “sand-size suspended-sediment load,” and so on. It is not synonymous with either suspended- sediment discharge or concentration. (See also “Sediment”) Suspended, total is the total amount of a given constituent in the part of a water-sediment sample that is retained on a 0.45-micrometer membrane filter. This term is used only when the analytical procedure assures measurement of at least 95 percent of the constituent determined. Knowledge of the expected form of the constituent in the sample, as well as the analytical methodology used, is required to determine when the results should be reported as “suspended, total.” Determinations of “suspended, total” constituents are made either by directly analyzing portions of the suspended material collected on the filter or, more commonly, by difference, based on determinations of (1) dissolved and (2) total concentrations of the constituent. (See also “Suspended”) Suspended solids, total residue at 105 °C concentration is the concentration of inorganic and organic material retained on a filter, expressed as milligrams of dry material per liter of water (mg/L). An aliquot of the sample is used for this analysis. 42 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Synoptic studies are short-term investigations of specific water-quality conditions during selected seasonal or hydrologic periods to provide improved spatial resolution for critical water-quality conditions. For the period and conditions sampled, they assess the spatial distribution of selected water-quality conditions in relation to causative factors, such as land use and contaminant sources. Taxa richness is the total number of distinct species or groups and usually decreases with pollution. (See also “Percent Shading”) Taxonomy is the division of biology concerned with the classification and naming of organisms. The classification of organisms is based upon a hierarchical scheme beginning with Kingdom and ending with Species at the base. The higher the classification level, the fewer features the organisms have in common. For example, the taxonomy of a particular mayfly, Hexagenia limbata, is the following: Kingdom: Animal Phylum: Arthropoda Class: Insecta Order: Ephemeroptera Family: Ephemeridae Genus: Hexagenia Species: Hexagenia limbata Temperature preferences: Cold – preferred water temperature for the species is less than 20 °C or spawning temperature preference less than 16 °C and native distribution is considered to be predominantly north of 45° N. latitude. Warm – preferred water temperatures for the species is greater than 20 °C or spawning temperature preference greater than 16 °C and native distribution is considered to be predominantly south of 45° N. latitude. Cool – intermediate between cold and warm water temperature preferences. Thermograph is an instrument that continuously records variations of temperature on a chart. The more general term “temperature recorder’ is used in the table descriptions 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 resulting from the mixing of flow proportionally to the duration of the concentration. Tons per acre-foot (T/acre-ft) is the dry mass (tons) of a constituent per unit volume (acre-foot) of water. It is computed by multiplying the concentration of the constituent, in milligrams per liter, by 0.00136. Tons per day (T/DAY, tons/d) is a common chemical or sediment discharge unit. It is the quantity of a substance in solution, in suspension, or as bedload that passes a stream section during a 24-hour period. It is equivalent to 2,000 pounds per day, or 0.9072 metric tons per day. Total is the amount of a given constituent in a representative whole-water (unfiltered) 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 at least 95 percent of the constituent in the sample.) Total coliform bacteria are a particular group of bacteria that are used as indicators of possible sewage pollution. This group includes coliforms that inhabit the intestine of warm-blooded animals and those that inhabit soils. They are characterized as aerobic or facultative anaerobic, gram-negative, nonspore-forming, rod-shaped bacteria that ferment lactose with gas formation within 48 hours at 35 °C. In the laboratory, these bacteria are defined as all the organisms that produce colonies with a golden-green metallic sheen within 24 hours when incubated at 35 °C plus or minus 1.0 °C on M-Endo medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. (See also “Bacteria”) 43 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Total discharge is the quantity of a given constituent, measured as dry mass or volume, that passes a stream cross section per unit of time. When referring to constituents other than water, this term needs to be qualified, such as “total sediment discharge,” “total chloride discharge,” and so on. Total in bottom material is the amount of a given constituent in a representative sample of bottom material. This term is used only when the analytical procedure assures measurement of at least 95 percent of the constituent determined. A knowledge of the expected form of the constituent in the sample, as well as the analytical methodology used, is required to judge when the results should be reported as “total in bottom material.” Total length (fish) is the straight-line distance from the anterior point of a fish specimen’s snout, with the mouth closed, to the posterior end of the caudal (tail) fin, with the lobes of the caudal fin squeezed together. Total load refers to all of a constituent in transport. When referring to sediment, it includes suspended load plus bed load. Total organism count is the number of organisms collected and enumerated in any particular sample. (See also “Organism count/volume.”) Total recoverable is the amount of a given constituent in a whole-water sample after a sample has been digested by a method (usually using a dilute acid solution) that results in dissolution of only readily soluble substances. Complete dissolution of all particulate matter is not achieved by the digestion treatment, and thus the determination represents something less than the “total” amount (that is, less than 95 percent) of the constituent present in the dissolved and suspended phases of the sample. To achieve comparability of analytical data for whole-water samples, equivalent digestion procedures are required of all laboratories performing such analyses because different digestion procedures may produce different analytical results. Total sediment discharge is the mass of suspended-sediment plus bed-load transport, measured as dry weight, that passes a cross section in a given time. It is a rate and is reported as tons per day. (See also “Sediment,” “Suspended sediment,” “Suspended-Sediment Concentration,” “Bedload,” and “Bedload discharge”) Total sediment load or total load is the sediment in transport as bedload and suspended-sediment load. The term may be qualified, such as “annual suspended-sediment load” or “sand-size suspended-sediment load,” and so on. It differs from total sediment discharge in that load refers to the material whereas discharge refers to the quantity of material, expressed in units of mass per unit time. (See also “Sediment,” “Suspended-Sediment Load,” and “Total load”) Trophic group: Filter feeder – diet composed of suspended plant and/or animal material. Herbivore – diet composed predominantly of plant material. Invertivore – diet composed predominantly of invertebrates. Omnivore – diet composed of at least 25-percent plant and 25-percent animal material. Piscivore – diet composed predominantly of fish. Turbidity is the reduction in the transparency of a solution due to the presence of suspended and some dissolved substances. The measurement technique records the collective optical properties of the solution that cause light to be scattered and attenuated rather than transmitted in straight lines; the higher the intensity of scattered or attenuated light, the higher the value of the turbidity. Turbidity is expressed in nephelometric turbidity units (NTU). Depending on the method used, the turbidity units as NTU can be defined as the intensity of light of a specified wavelength scattered or attenuated by suspended particles or absorbed at a method specified angle, usually 90 degrees, from the path of the incident light. Currently approved methods for the measurement of turbidity in the USGS include those that conform to EPA Method 180.1, ASTM D1889-00, and ISO 7027. Measurements of turbidity by these different methods and different instruments are unlikely to yield equivalent values. Consequently, the method of measurement and type of instrument used to derive turbidity records should be included in the “REMARKS” column of the Annual Data Report. 44 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 Ultraviolet (UV) absorbance (absorption) at 254 or 280 nanometers is a measure of the aggregate concentration of the mixture of UV absorbing organic materials dissolved in the analyzed water, such as lignin, tannin, humic substances, and various aromatic compounds. UV absorbance (absorption) at 254 or 280 nanometers is measured in UV absorption units per centimeter of pathlength of UV light through a sample. Vertical datum (See “Datum”) Volatile organic compounds (VOCs) are organic compounds that can be isolated from the water phase of a sample by purging the water sample with inert gas, such as helium, and subsequently analyzed by gas chromatography. Many VOCs are human-made chemicals that are used and produced in the manufacture of paints, adhesives, petroleum products, pharmaceuticals, and refrigerants. They are often components of fuels, solvents, hydraulic fluids, paint thinners, and dry cleaning agents commonly used in urban settings. VOC contamination of drinking-water supplies is a human health concern because many are toxic and are known or suspected human carcinogens (U.S. Environmental Protection Agency, 1996). Water table is the level in the saturated zone at which the pressure is equal to the atmospheric pressure. Water-table aquifer is an unconfined aquifer within which is found the water table. Water year in USGS 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, 2001, is called the “2001 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. Wet mass is the mass of living matter plus contained water. (See also “Biomass” and “Dry mass”) Wet weight refers to the weight of animal tissue or other substance including its contained water. (See also “Dry weight”) WSP is used as an acronym for “Water-Supply Paper” in reference to previously published reports. 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. (See also “Plankton”) 45 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS OF THE U.S. GEOLOGICAL SURVEY The U.S.G.S. publishes a series of manuals describing procedures for planning and conducting specialized work in water-resources investigations. The material is grouped under major subject headings called books and is further divided into 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 flexibil- ity in revision and publication as the need arises. The reports listed below are for sale by the U.S.G.S., Information Services, Box 25286, Federal Center, Denver, Colorado 80225 (authorized agent of the Superintendent of Documents, Government Printing Office). Prepayment is required. Remittance should be made in the form of a check or money order payable to the “U.S. Geological Survey.” Prices are not included because they are subject to change. Current prices can be obtained by writing to the above address. When ordering or inquiring about prices for any of these publications, please give the title, book number, chapter number, and mention the “U.S. Geological Survey Techniques of Water-Resources Investigations.” Book 1. Collection of Water Data by Direct Measurement Section D. Water Quality 1-D1. Water temperature—influential factors, field measurement, and data presentation, by H. H. Stevens, Jr., J.F. Ficke, and G. F. Smoot: USGS–TWRI book 1, chap. D1. 1975. 65 p. 1-D2. Guidelines for collection and field analysis of ground-water samples for selected unstable constituents, by W.W. Wood: USGS–TWRI book 1, chap. D2. 1976. 24 p. Book 2. Collection of Environmental Data Section D. Surface Geophysical Methods 2-D1. Application of surface geophysics to ground-water investigations, by A.A. R. Zohdy, G.P. Eaton, and D.R. Mabey: USGS–TWRI book 2, chap. D1. 1974. 116 p. 2-D2. Application of seismic-refraction techniques to hydrologic studies, by F.P. Haeni: USGS–TWRI book 2, chap. D2. 1988. 86 p. Section E. Subsurface Geophysical Methods 2-E1. Application of borehole geophysics to water-resources investigations, by W.S. Keys and L.M. MacCary: USGS–TWRI book 2, chap. E1. 1971. 126 p. 2-E2. Borehole geophysics applied to ground-water investigations, by W.S. Keys: USGS–TWRI book 2, chap. E2. 1990. 150 p. Section F. Drilling and Sampling Methods 2-F1. Application of drilling, coring, and sampling techniques to test holes and wells, by Eugene Shuter and W.E. Teasdale: USGS–TWRI book 2, chap. F1. 1989. 97 p. Book 3. Applications of Hydraulics Section A. Surface-Water Techniques 3-A1. General field and office procedures for indirect discharge measurements, by M.A. Benson and Tate Dalrymple: USGS– TWRI book 3, chap. A1. 1967. 30 p. 3-A2. Measurement of peak discharge by the slope-area method, by Tate Dalrymple and M.A. Benson: USGS–TWRI book 3, chap. A2. 1967. 12 p. 3-A3. Measurement of peak discharge at culverts by indirect methods, by G.L. Bodhaine: USGS–TWRI book 3, chap. A3. 1968. 60 p. 3-A4. Measurement of peak discharge at width contractions by indirect methods, by H.F. Matthai: USGS-TWRI book 3, chap. A4. 1967. 44 p. 3-A5. Measurement of peak discharge at dams by indirect methods, by Harry Hulsing: USGS–TWRI book 3. chap. A5. 1967. 29 p. 3-A6. General procedure for gaging streams, by R.W. Carter and Jacob Davidian: USGS–TWRI book 3, chap. A6. 1968. 13 p. 3-A7. Stage measurement at gaging stations, by T.J. Buchanan and W.P. Somers: USGS–TWRI book 3, chap. A7. 1968. 28 p. 46 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 PUBLICATIONS ON TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS—Continued 3-A8. Discharge measurements at gaging stations, by T.J. Buchanan and W.P. Somers: USGS–TWRI book 3, chap. A8. 1969. 65 p. 3-A9. Measurement of time of travel in streams by dye tracing, by F.A. Kilpatrick and J.F. Wilson, Jr.: USGS–TWRI book 3, chap. A9. 1989. 27 p. 3-Al0. Discharge ratings at gaging stations, by E.J. Kennedy: USGS–TWRI book 3, chap. A10. 1984. 59 p. 3-A11. Measurement of discharge by the moving-boat method, by G.F. Smoot and C.E. Novak: USGS–TWRI book 3, chap. A11. 1969. 22 p. 3-A12. Fluorometric procedures for dye tracing, Revised, by J.F. Wilson, Jr., E.D. Cobb, and F.A. Kilpatrick: USGS–TWRI book 3, chap. A12. 1986. 34 p. 3-A13. Computation of continuous records of streamflow, by E.J. Kennedy: USGS–TWRI book 3, chap. A13. 1983. 53 p. 3-A14. Use of flumes in measuring discharge, by F.A. Kilpatrick and V.R. Schneider: USGS–TWRI book 3, chap. A14. 1983. 46 p. 3-A15. Computation of water-surface profiles in open channels, by Jacob Davidian: USGS–TWRI book 3, chap. A15. 1984. 48 p. 3-A16. Measurement of discharge using tracers, by F.A. Kilpatrick and E.D. Cobb: USGS–TWRI book 3, chap. A16. 1985. 52 p. 3-A17. Acoustic velocity meter systems, by Antonius Laenen: USGS–TWRI book 3, chap. A17. 1985. 38 p. 3-A18. Determination of stream reaeration coefficients by use of tracers, by F.A. Kilpatrick, R.E. Rathbun, Nobuhiro Yotsukura, G.W. Parker, and L.L. DeLong: USGS–TWRI book 3, chap. A18. 1989. 52 p. 3-A19. Levels at streamflow gaging stations, by E.J. Kennedy: USGS–TWRI book 3, chap. A19. 1990. 31 p. 3-A20. Simulation of soluble waste transport and buildup in surface waters using tracers, by F.A. Kilpatrick: USGS–TWRI book 3, chap. A20. 1993. 38 p. 3-A21 Stream-gaging cableways, by C. Russell Wagner: USGS–TWRI book 3, chap. A21. 1995. 56 p. Section B. Ground-Water Techniques 3-B1. Aquifer-test design, observation, and data analysis, by R.W. Stallman: USGS–TWRI book 3, chap. B1. 1971. 26 p. 3-B2. Introduction to ground-water hydraulics, a programed text for self-instruction, by G.D. Bennett: USGS–TWRI book 3, chap. B2. 1976. 172 p. 3-B3. Type curves for selected problems of flow to wells in confined aquifers, by J.E. Reed: USGS–TWRI book 3, chap. B3. 1980. 106 p. 3-B4. Regression modeling of ground-water flow, by R.L. Cooley and R.L. Naff: USGS–TWRI book 3, chap. B4. 1990. 232 p. 3-B4. Supplement 1. Regression modeling of ground-water flow --Modifications to the computer code for nonlinear regression solution of steady-state ground-water flow problems, by R.L. Cooley: USGS–TWRI book 3, chap. B4. 1993. 8 p. 3-B5. Definition of boundary and initial conditions in the analysis of saturated ground-water flow systems—An introduction, by O.L. Franke, T.E. Reilly, and G.D. Bennett: USGS–TWRI book 3, chap. B5. 1987. 15 p. 3-B6. The principle of superposition and its application in ground-water hydraulics, by T.E. Reilly, O.L. Franke, and G.D. Bennett: USGS–TWRI book 3, chap. B6. 1987. 28 p. 3-B7. Analytical solutions for one-, two-, and three-dimensional solute transport in ground-water systems with uniform flow, by E.J. Wexler: USGS–TWRI book 3, chap. B7. 1992. 190 p. 3-B8. System and boundary conceptualization in ground-water flow simulation, by T.E. Reilly: USGS–TWRI book 3, chap. B8. 2001. 29 p. Section C. Sedimentation and Erosion Techniques 3-C1. Fluvial sediment concepts, by H.P. Guy: USGS–TWRI book 3, chap. C1. 1970. 55 p. 3-C2. Field methods for measurement of fluvial sediment, by T.K. Edwards and G.D. Glysson: USGS–TWRI book 3, chap. C2. 1999. 89 p. 3-C3. Computation of fluvial-sediment discharge, by George Porterfield: USGS–TWRI book 3, chap. C3. 1972. 66 p. 47 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 PUBLICATIONS ON TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS—Continued Book 4. Hydrologic Analysis and Interpretation Section A. Statistical Analysis 4-A1. Some statistical tools in hydrology, by H.C. Riggs: USGS–TWRI book 4, chap. A1. 1968. 39 p. 4-A2. Frequency curves, by H.C. Riggs: USGS–TWRI book 4, chap. A2. 1968. 15 p. Section B. Surface Water 4-B1. Low-flow investigations, by H.C. Riggs: USGS–TWRI book 4, chap. B1. 1972. 18 p. 4-B2. Storage analyses for water supply, by H.C. Riggs and C.H. Hardison: USGS–TWRI book 4, chap. B2. 1973. 20 p. 4-B3. Regional analyses of streamflow characteristics, by H.C. Riggs: USGS–TWRI book 4, chap. B3. 1973. 15 p. Section D. Interrelated Phases of the Hydrologic Cycle 4-D1. Computation of rate and volume of stream depletion by wells, by C.T. Jenkins: USGS–TWRI book 4, chap. D1. 1970. 17 p. Book 5. Laboratory Analysis Section A. Water Analysis 5-A1. Methods for determination of inorganic substances in water and fluvial sediments, by M.J. Fishman and L.C. Friedman, editors: USGS–TWRI book 5, chap. A1. 1989. 545 p. 5-A2. Determination of minor elements in water by emission spectroscopy, by P.R. Barnett and E.C. Mallory, Jr.: USGS–TWRI book 5, chap. A2. 1971. 31 p. 5-A3. Methods for the determination of organic substances in water and fluvial sediments, edited by R.L. Wershaw, M.J. Fishman, R.R. Grabbe, and L.E. Lowe: USGS–TWRI book 5, chap. A3. 1987. 80 p. 5-A4. Methods for collection and analysis of aquatic biological and microbiological samples, by L.J. Britton and P.E. Greeson, editors: USGS–TWRI book 5, chap. A4. 1989. 363 p. 5-A5. Methods for determination of radioactive substances in water and fluvial sediments, by L.L. Thatcher, V.J. Janzer, and K.W. Edwards: USGS–TWRI book 5, chap. A5. 1977. 95 p. 5-A6. Quality assurance practices for the chemical and biological analyses of water and fluvial sediments, by L.C. Friedman and D.E. Erdmann: USGS–TWRI book 5, chap. A6. 1982. 181 p. Section C. Sediment Analysis 5-C1. Laboratory theory and methods for sediment analysis, by H.P. Guy: USGS–TWRI book 5, chap. C1. 1969. 58 p. Book 6. Modeling Techniques Section A. Ground Water 6-A1. A modular three-dimensional finite-difference ground-water flow model, by M.G. McDonald and A.W. Harbaugh: USGS–TWRI book 6, chap. A1. 1988. 586 p. 6-A2. Documentation of a computer program to simulate aquifer-system compaction using the modular finite- difference ground-water flow model, by S.A. Leake and D.E. Prudic: USGS–TWRI book 6, chap. A2. 1991. 68 p. 6-A3. A modular finite-element model (MODFE) for areal and axisymmetric ground-water-flow problems, Part 1: Model Description and User’s Manual, by L.J. Torak: USGS–TWRI book 6, chap. A3. 1993. 136 p. 6-A4. A modular finite-element model (MODFE) for areal and axisymmetric ground-water-flow problems, Part 2: Derivation of finite-element equations and comparisons with analytical solutions, by R.L. Cooley: USGS– TWRI book 6, chap. A4. 1992. 108 p. 6-A5. A modular finite-element model (MODFE) for areal and axisymmetric ground-water-flow problems, Part 3: Design philosophy and programming details, by L.J. Torak: USGS–TWRI book 6, chap. A5, 1993. 243 p. 6-A6. A coupled surface-water and ground-water flow model (MODBRANCH) for simulation of stream-aquifer interaction, by Eric D. Swain and Eliezer J. Wexler: USGS–TWRI book 6, chap. A5,1996. 125 p. 48 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2001 PUBLICATIONS ON TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS—Continued Book 7. Automated Data Processing and Computations Section C. Computer Programs 7-C1. Finite difference model for aquifer simulation in two dimensions with results of numerical experiments, by P.C. Trescott, G.F. Pinder, and S.P. Larson: USGS–TWRI book 7, chap. C1. 1976. 116 p. 7-C2. Computer model of two-dimensional solute transport and dispersion in ground water, by L.F. Konikow and J.D. Bredehoeft: USGS–TWRI book 7, chap. C2. 1978. 90 p. 7-C3. A model for simulation of flow in singular and interconnected channels, by R.W. Schaffranek, R.A. Baltzer, and D.E. Goldberg: USGS–TWRI book 7, chap. C3. 1981. 110 p. Book 8. Instrumentation Section A. Instruments for Measurement of Water Level 8-A1. Methods of measuring water levels in deep wells, by M.S. Garber and F.C. Koopman: USGS–TWRI book 8, chap. A1. 1968. 23 p. 8-A2. Installation and service manual for U.S. Geological Survey manometers, by J.D. Craig: USGS–TWRI book 8, chap. A2. 1983. 57 p. Section B. Instruments for Measurement of Discharge 8-B2. Calibration and maintenance of vertical-axis type current meters, by G.F. Smoot and C.E. Novak: USGS–TWRI book 8, chap. B2. 1968. 15 p. Book 9. Handbooks for Water-Resources Investigations Section A. National Field Manual for the Collection of Water-Quality Data 9-A1. National Field Manual for the Collection of Water-Quality Data: Preparations for Water Sampling, by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A1. 1998. 47 p. 9-A2. National Field Manual for the Collection of Water-Quality Data: Selection of Equipment for Water Sampling, edited by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A2. 1998. 94 p. 9-A3. National Field Manual for the Collection of Water-Quality Data: Cleaning of Equipment for Water Sampling, edited by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A3. 1998. 75 p. 9-A4. National Field Manual for the Collection of Water-Quality Data: Collection of Water Samples, edited by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A4. 1999. 156 p. 9-A5. National Field Manual for the Collection of Water-Quality Data: Processing of Water Samples, edited by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A5. 1999, 149 p. 9-A6. National Field Manual for the Collection of Water-Quality Data: Field Measurements, edited by F.D. Wilde and D.B. Radtke: USGS–TWRI book 9, chap. A6. 1998. Variously paginated. 9-A7. National Field Manual for the Collection of Water-Quality Data: Biological Indicators, edited by D.N. Myers and F.D. Wilde: USGS–TWRI book 9, chap. A7. 1997 and 1999. Variously paginated. 9-A8. National Field Manual for the Collection of Water-Quality Data: Bottom-material samples, by D.B. Radtke: USGS– TWRI book 9, chap. A8. 1998. 48 p. 9-A9. National Field Manual for the Collection of Water-Quality Data: Safety in Field Activities, by S.L. Lane and R.G. Fay: USGS–TWRI book 9, chap. A9. 1998. 60 p. 49 50 THIS PAGE IS INTENTIONALLY BLANK 51 Figure 11. Río Guajataca basin. 52 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR LOCATION.--Lat 18°18'01", long 66°52'24", Hydrologic Unit 21010001 at bridge on Highway 111, 0.1 mi (0.2 km) upstream from Quebrada Anón, and 0.4 mi (0.6 km) east of Lares. DRAINAGE AREA.--3.16 mi2 (8.18 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1959 to February 1962 (annual low-flow measurements only), January 1963 to April 1969 (monthly measurements only), May 1969 to December 1970 (February to May 1971 and March 1974 to November 1989, monthly measurements only), December 1989 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 935 ft (285 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. Small diversion above station for sewage treatment plant; effluent re-enters stream below station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 4.3 21 1.7 2.0 1.1 1.3 1.5 3.6 2.6 4.8 2.8 54 2 4.2 9.4 1.6 1.8 1.8 1.4 3.3 1.9 2.8 3.6 2.5 12 3 9.5 13 2.0 1.9 1.7 1.3 1.5 2.3 2.4 3.4 3.6 9.6 4 4.9 7.4 1.7 1.9 1.5 1.2 .95 1.4 2.4 5.3 3.3 10 5 3.9 7.1 1.8 1.7 1.6 1.2 3.1 1.3 14 3.8 2.3 8.7 6 3.4 6.7 2.1 1.9 e14 1.2 6.4 59 3.7 3.3 39 23 7 4.9 5.9 1.6 2.0 11 1.2 2.2 e18 e2.8 3.1 7.3 9.1 8 3.5 5.6 1.6 2.0 4.2 1.3 1.4 e42 2.5 2.9 4.0 7.3 9 2.9 5.4 2.2 1.5 2.3 1.4 1.2 e18 2.1 2.8 3.0 19 10 4.2 4.9 2.6 1.2 2.4 1.3 1.0 e26 e1.9 12 3.2 9.8 11 25 4.7 1.9 2.0 1.4 1.4 1.1 e11 e2.0 e40 18 7.3 12 e47 4.6 2.2 2.4 1.6 1.2 1.1 6.1 2.4 42 5.3 8.2 13 6.8 4.4 2.1 1.1 1.9 1.5 1.0 4.4 12 11 3.1 6.3 14 4.7 3.9 2.5 2.1 1.7 1.6 .97 5.3 3.6 46 51 5.8 15 14 3.9 2.8 1.8 2.3 1.8 .89 6.0 2.4 14 30 21 16 12 3.7 2.4 2.0 1.6 1.7 .96 5.8 6.8 7.4 9.6 6.8 17 6.3 3.6 1.9 1.5 1.4 1.6 1.0 3.8 e15 6.2 7.5 24 18 4.4 3.4 1.6 1.3 2.0 1.7 1.1 4.1 16 8.3 6.1 10 19 53 3.3 e1.5 1.3 1.6 1.5 .85 4.6 4.1 5.7 30 7.3 20 20 2.9 e1.5 1.1 1.7 1.8 .84 3.0 2.8 7.8 8.0 52 21 20 3.1 1.6 1.7 2.7 1.7 1.1 3.1 2.5 3.9 6.1 68 22 15 2.9 1.5 1.6 5.3 2.1 2.3 3.6 2.9 7.6 8.0 19 23 51 2.7 1.7 1.5 1.9 14 1.6 2.8 24 7.8 20 24 24 17 2.6 1.7 1.4 3.3 8.0 3.6 2.7 e10 3.7 11 15 25 12 2.4 1.8 1.3 2.5 2.4 12 2.6 6.9 3.1 6.8 29 26 11 2.0 1.6 1.6 2.2 2.1 58 2.8 5.1 9.3 6.1 23 27 34 2.2 1.6 4.2 2.4 1.8 e5.6 5.1 3.3 8.0 6.5 20 28 11 1.9 e2.1 3.3 1.8 4.6 2.1 3.0 3.3 4.7 5.4 16 29 9.3 1.7 2.2 4.9 --- 2.5 9.8 2.6 12 5.0 33 14 30 24 2.0 1.9 4.8 --- 1.7 6.1 5.2 5.7 3.4 13 13 31 9.4 --- 1.9 1.4 --- 1.3 --- 3.3 --- 2.9 9.7 --- TOTAL 452.6 148.3 58.9 62.2 80.9 70.8 134.56 264.4 180.0 292.8 365.2 552.2 MEAN 14.6 4.94 1.90 2.01 2.89 2.28 4.49 8.53 6.00 9.45 11.8 18.4 MAX 53 21 2.8 4.9 14 14 58 59 24 46 51 68 MIN 2.9 1.7 1.5 1.1 1.1 1.2 .84 1.3 1.9 2.8 2.3 5.8 AC-FT 898 294 117 123 160 140 267 524 357 581 724 1100 CFSM 4.62 1.56 .60 .63 .91 .72 1.42 2.70 1.90 2.99 3.73 5.82 IN. 5.33 1.75 .69 .73 .95 .83 1.58 3.11 2.12 3.45 4.30 6.50 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2001, BY WATER YEAR (WY) MEAN 17.5 9.55 4.01 3.27 2.97 2.77 3.62 11.0 8.25 5.01 6.95 15.0 MAX 33.7 25.8 8.32 8.91 7.21 10.6 8.16 25.4 23.4 9.85 11.8 45.2 (WY) 1991 2000 2000 1997 1996 1999 1999 1999 1999 1969 2001 1998 MIN 8.52 2.42 1.35 .66 .93 .92 1.09 2.37 1.70 1.73 3.34 5.95 (WY) 1995 1998 1991 1991 1992 1994 1994 1997 1997 1997 1970 1993 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1969 - 2001 ANNUAL TOTAL 2544.04 2662.86 ANNUAL MEAN 6.95 7.30 7.46 HIGHEST ANNUAL MEAN 12.6 1999 LOWEST ANNUAL MEAN 4.13 1994 HIGHEST DAILY MEAN 183 May 11 68 Sep 21 505 Sep 22 1998 LOWEST DAILY MEAN .94 Jul 5 .84 Apr 20 .47 Jan 13 1991 ANNUAL SEVEN-DAY MINIMUM 1.6 Dec 18 .94 Apr 14 .51 Jan 9 1991 MAXIMUM PEAK FLOW 1700 Sep 21 5300 Oct 7 1990 MAXIMUM PEAK STAGE 14.72 Sep 21 21.30 Oct 7 1990 ANNUAL RUNOFF (AC-FT) 5050 5280 5410 ANNUAL RUNOFF (CFSM) 2.20 2.31 2.36 ANNUAL RUNOFF (INCHES) 29.95 31.35 32.08 10 PERCENT EXCEEDS 15 18 17 50 PERCENT EXCEEDS 3.4 3.3 3.7 90 PERCENT EXCEEDS 1.7 1.4 1.0 e Estimated 53 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR--Continued O N D 2000 J F M A M J J A S 2001 0.1 0.2 0.5 1 2 5 10 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND 54 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR--Continued WATER-QUALITY RECORDS LOCATION.--Lat 18°18'01", long 66°52'24", at bridge on Highway 111 (km 32.9), 0.1 mi (0.2 km) upstream from Quebrada Anón, and 0.4 mi (0.6 km) northeast of Lares plaza. DRAINAGE AREA.--3.16 mi2 (8.18 km2). PERIOD OF RECORD.--Water years 1958-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 19... 1220 4.4 257 7.4 23.1 3.0 7.9 95 <10 4200 2400 95 28.8 FEB 14... 1100 1.3 258 7.3 21.0 2.6 7.6 88 <10 600 2000 -- -- MAY 14... 1115 2.9 309 7.4 23.3 8.1 7.3 89 <10 E680 490 120 39.2 SEP 05... 1345 7.6 208 7.3 24.4 -- 7.2 89 <10 E7500 4000 89 26.6 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 19... 5.55 11.1 .5 2.52 97 <1.0 7.6 11.5 <.2 31.7 157 1.87 <10 FEB 14... -- -- -- -- 95 -- -- -- -- -- -- -- <10 MAY 14... 6.11 11.9 .5 2.41 119 <1.0 13.2 11.8 <.2 27.3 183 1.45 <10 SEP 05... 5.43 10.5 .5 2.35 89 -- 6.6 10.9 <.2 27.6 143 2.93 <10 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) OCT 19... 1.69 .01 1.7 .03 .21 .24 1.9 8.6 .060 <2 24.6 E16 <.11 FEB 14... -- <.01 .6 .06 .21 .27 .87 3.9 <.020 -- -- -- -- MAY 14... -- <.01 1.1 .04 .26 .30 1.4 6.2 .040 2 30.6 22 <.11 SEP 05... -- <.01 1.8 .17 .26 .43 2.2 9.9 .040 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 19... <1 <20.0 180 <1 30 <.14 <2.6 <.43 <31 <.01 <16 .07 FEB 14... -- -- -- -- -- -- -- -- -- -- -- -- MAY 14... <1 <20.0 100 <1 31 <.01 <2.6 <.43 <31 <.01 <16 <.02 SEP 05... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 55 RIO GUAJATACA BASIN 50010800 LAGO GUAJATACA AT DAMSITE NEAR QUEBRADILLAS, PR LOCATION.--Lat 18°24'02", long 66°55'25", Hydrologic Unit 21010002, on right bank, in a concrete intake tower at Damsite, 5.2 mi (8.4 km) southeast from Quebradillas plaza, 0.5 mi (0.8 km) northeast from Iglesia San Antonio de Padua and 2.8 mi (4.5 km) from Escuela Segunda Unidad Baldorioty de Castro. DRAINAGE AREA.--24.6 mi2 (63.71 km2) ELEVATION RECORDS PERIOD OF RECORD.--April 1995 to current year. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Guajataca was completed in 1928. The dam is a semihydraulic earthfill structure about 123 ft (37 m) high, a top width of 31 ft (9.5 m) at crest elevation of 664 ft (202.5 m), a base width of 623 ft (190 m), a crest length of 1,036 ft (316 m) and has a maximum storage capacity of 49,200 acre- feet (60.6 hm3). The Guajataca Dam is owned by the Puerto Rico Electric Power Authority (P.R.E.P.A) and provides water for the municipalities of Aguadilla, Isabela, Moca, Aguada and Quebradillas although its primary purpose is for agricultural irrigation for the flatlands of the area. Gage-height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 00-4044,January 1999. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 648.3 ft (197.60 m), Sept. 23, 1998; minimum elevation, 608.07 ft (185.34 m) May 17, 1998. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 643.58 ft (196.16 m), Oct. 22; minimum elevation, 622.77 ft (189.82 m), Apr. 25. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 00-4044,Puerto Rico-1999) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 557 0 616 13,393 577 916 636 26,332 597 5,253 646 34,277 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 636.65 643.07 640.17 636.51 633.67 630.36 626.87 626.47 638.69 639.60 637.69 A 2 636.65 642.93 640.06 636.39 633.53 630.22 626.74 626.37 638.77 639.57 637.59 638.13 3 636.69 642.55 639.93 636.29 633.39 630.06 626.58 626.24 638.75 639.50 637.48 A 4 636.67 641.91 639.81 636.15 633.24 629.99 626.41 626.09 638.66 639.53 637.49 A 5 636.64 641.96 639.70 636.03 633.09 630.00 626.23 625.92 638.73 A 637.41 A 6 636.57 641.97 639.60 635.89 632.98 629.89 626.11 628.54 638.71 639.58 637.86 638.05 7 636.61 641.96 639.49 635.75 632.95 629.73 625.97 630.32 638.63 639.54 638.01 A 8 636.61 641.96 639.37 635.65 632.85 629.56 625.81 632.05 638.55 639.48 637.91 637.85 9 636.79 642.05 639.25 635.67 632.73 629.39 625.65 633.07 638.47 639.38 637.86 A 10 637.24 642.01 639.13 635.35 632.57 629.22 625.29 635.60 638.34 639.31 637.77 638.17 11 637.58 641.95 638.71 635.22 632.41 629.06 625.14 636.69 638.30 639.46 637.80 638.18 12 639.52 641.89 638.63 635.11 632.26 628.90 624.93 637.17 638.21 640.07 637.77 638.19 13 640.23 641.82 638.53 634.97 632.12 628.71 624.72 637.38 638.64 640.20 637.69 638.24 14 640.45 641.74 638.43 634.84 631.94 628.54 624.55 637.32 638.91 640.71 A 638.20 15 640.59 641.67 638.38 634.79 631.84 628.38 624.37 637.87 638.85 641.00 638.27 638.85 16 640.64 641.57 638.27 634.66 631.77 628.19 624.18 638.09 638.86 641.08 638.34 639.08 17 640.88 641.48 638.17 634.54 631.65 628.01 624.00 638.14 639.14 640.99 638.34 641.40 18 641.36 641.39 638.05 634.37 631.62 627.82 623.80 638.18 639.35 640.80 638.23 642.53 19 643.04 641.30 637.94 634.22 631.57 627.63 623.63 638.19 639.37 640.28 638.25 642.18 20 643.54 641.22 637.90 634.08 631.49 627.50 623.44 638.15 639.33 640.11 638.19 642.00 21 643.57 641.12 637.79 633.93 631.39 627.34 623.26 638.08 639.26 639.89 638.14 641.57 22 643.44 641.03 637.66 633.78 631.37 627.21 623.06 638.09 639.17 639.71 638.07 641.48 23 643.46 641.01 637.53 633.64 631.29 627.15 622.90 638.12 639.16 639.71 638.08 641.76 24 643.15 640.93 637.41 633.49 631.25 627.11 622.88 638.08 639.24 639.43 638.10 641.80 25 642.68 640.80 637.30 633.35 631.20 626.97 623.58 638.03 639.31 639.11 638.01 641.38 26 642.14 640.70 637.29 633.26 631.07 626.81 625.41 A 639.30 638.82 637.92 640.99 27 643.01 640.61 637.18 633.32 631.21 626.65 A 638.71 639.22 638.54 637.81 640.71 28 643.21 640.51 637.05 633.22 630.74 627.08 625.97 638.89 639.12 638.23 637.72 640.79 29 642.64 640.40 636.91 633.60 --- 627.24 625.91 638.85 639.28 638.21 637.80 640.77 30 642.83 640.29 636.78 633.89 --- 627.15 626.37 638.80 639.60 637.98 637.83 640.80 31 642.81 --- 636.66 633.79 --- 626.99 --- 638.73 --- 637.77 637.76 --- MAX 643.57 643.07 640.17 636.51 633.67 630.36 --- --- 639.60 --- --- --- MIN 636.57 640.29 636.66 633.22 630.74 626.65 --- --- 638.21 --- --- --- A No gage-height record 56 RIO GUAJATACA BASIN 50010800 LAGO GUAJATACA AT DAMSITE NEAR QUEBRADILLAS, PR--Continued O N D 2000 J F M A M J J A S 2001 620 625 630 635 640 645 ELEVATION, IN FEET Gap indicates missing record 57 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 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 16... 1445 70 332 7.3 25.5 1.4 .3 4 <10 21 E7 160 56.2 FEB 14... 1345 E65 321 7.3 24.9 .8 2.2 27 <10 E2 140 -- -- MAY 09... 1100 70 312 7.8 25.3 3.8 .9 12 <10 180 110 140 51.2 SEP 13... 1230 70 301 7.2 26.6 -- 1.4 17 <10 E52 E15 140 49.7 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 16... 3.60 5.3 .2 1.99 151 <1.0 7.0 7.8 E.1 7.3 180 33.9 <10 FEB 14... -- -- -- -- 141 -- -- -- -- -- -- -- <10 MAY 09... 3.67 5.9 .2 2.13 139 <1.0 8.3 9.1 E.1 6.2 170 32.2 <10 SEP 13... 3.69 5.7 .2 2.07 136 -- 8.8 7.9 <.2 7.6 167 31.6 <10 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) OCT 16... -- <.01 <.02 .71 .39 1.1 -- -- <.020 3 23.1 E11 <.11 FEB 14... 1.48 .02 1.5 .03 .25 .28 1.8 7.9 .050 -- -- -- -- MAY 09... -- <.01 M .43 .23 .66 .68 3.0 <.020 2 19.1 E16 <.11 SEP 13... -- <.01 <.02 .23 .27 .50 -- -- <.020 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 16... <1 <20.0 280 <1 230 <.14 <2.6 <.43 <31 <.01 <16 .06 FEB 14... -- -- -- -- -- -- -- -- -- -- -- -- MAY 09... <1 <20.0 210 <1 188 <.01 <2.6 <.43 <31 <.01 <16 <.02 SEP 13... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 58 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR. WATER-QUALITY RECORDS LOCATION.--Lat 18°28'31", long 66°57'46", Hydrologic Unit 21010002, on left bank at ford 1.7 mi (2.7 km) upstream from bridge on highway 2, 1.6 mi (2.6 km) west of Quebradillas plaza, 2.1 mi (3.4 km) upstream from Atlantic Ocean, and 6.6 mi (10.6 km) downstream from Lago Guajataca. DRAINAGE AREA.--Indeterminate PERIOD OF RECORD.--Water years 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 18... 1035 72 363 7.7 24.3 23 7.2 86 <10 >6000 >6000 170 61.3 FEB 15... 1245 9.4 567 7.4 24.1 .4 6.7 80 <10 E57 220 -- -- MAY 09... 0850 61 365 7.7 24.1 9.3 7.1 84 <10 760 860 170 63.6 SEP 18... 1030 71 259 7.4 24.5 -- 6.8 81 15 E18000 20000 120 43.3 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 18... 3.76 6.7 .2 1.44 163 <1.0 6.8 11.8 <.2 5.7 195 38.0 23 FEB 15... -- -- -- -- 223 -- -- -- -- -- -- -- <10 MAY 09... 3.57 6.9 .2 1.88 162 <1.0 9.4 11.6 <.2 6.2 200 32.9 10 SEP 18... 2.67 4.9 .2 2.65 114 -- 6.2 9.7 <.2 5.7 144 27.4 20 NITRO- CHRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) OCT 18... <.01 .7 <.01 -- .54 1.3 5.6 .020 E1 13.0 19 <.11 3 FEB 15... <.01 .6 .02 -- <.20 -- -- <.020 -- -- -- -- -- MAY 09... <.01 .8 <.01 -- .22 1.1 4.6 <.020 <2 11.7 E14 <.11 <1 SEP 18... <.01 .8 .03 .57 .60 1.4 6.2 .060 -- -- -- -- -- 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- DATE (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) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 18... <20.0 400 <1 40 <.14 <2.6 <.43 <31 <.01 <16 <.02 FEB 15... -- -- -- -- -- -- -- -- -- -- -- MAY 09... <20.0 110 <1 16 <.01 <2.6 <.43 <31 <.01 <16 <.02 SEP 18... -- -- -- -- -- -- -- -- -- -- -- < -- Less than > -- Greater than E -- Estimated value 59 Figure 12. Río Camuy basin. 60 RIO CAMUY BASIN 50014800 RIO CAMUY NEAR BAYANEY, PR LOCATION.--Lat 18°23'48", long 66°49'04", Hydrologic Unit 21010002, on left bank at Highway 488, 1.4 mi (2.2 km) southeast of school at Santiago, 0.9 mi (1.4 km) northwest from Escuela Manuel A. Rivera at Bayaney and 9.1 mi (14.6 km) upstream from mouth. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--May 1984 to current year. GAGE.--Water-stage recorder. Elevation of gage is 341 ft (104 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 105 273 31 28 37 36 e29 90 47 e78 50 195 2 99 197 31 28 35 45 e28 55 69 e65 e53 148 3 228 199 30 29 33 35 e29 40 55 56 e52 83 4 146 122 30 29 32 31 e34 36 43 73 63 76 5 100 96 35 29 31 30 e29 34 44 68 49 84 6 86 80 35 30 45 29 e27 391 52 56 106 84 7 129 70 31 30 75 29 e33 628 40 48 103 79 8 111 63 30 30 72 29 e43 372 39 44 67 65 9 84 57 28 29 38 27 e31 328 38 43 53 71 10 237 51 28 29 33 27 e29 403 e37 57 47 97 11 160 47 28 30 32 26 28 323 e37 e81 103 96 12 376 43 29 31 31 25 28 193 e36 e142 107 67 13 284 42 28 32 31 26 27 108 64 e98 62 88 14 161 40 27 32 30 26 27 140 e96 e67 115 68 15 125 40 33 34 31 26 26 202 51 e126 e117 114 16 133 39 33 36 31 25 26 164 e39 72 e91 117 17 133 37 34 35 31 25 25 93 e119 e65 e69 154 18 164 36 31 33 31 24 25 77 147 e67 e68 147 19 310 35 30 32 31 e24 25 79 115 e70 e62 100 20 271 35 30 31 30 e24 25 e58 67 60 e78 173 21 155 34 29 31 30 24 25 e56 54 66 64 260 22 238 34 29 31 62 25 27 e60 48 62 e63 166 23 467 34 29 31 41 27 31 e49 105 e65 e142 169 24 257 34 29 31 35 62 36 e48 e116 e65 82 150 25 166 33 29 30 41 62 44 e45 173 55 e76 137 26 118 33 29 30 37 e48 329 e43 103 e51 e71 141 27 143 32 35 36 33 e31 e269 e80 71 e70 76 156 28 166 31 29 42 32 e31 e93 e46 64 75 67 144 29 106 e31 29 61 --- e30 57 e41 74 99 64 96 30 436 31 28 132 --- e38 88 44 130 79 107 83 31 271 --- 29 57 --- e32 --- 47 --- 60 88 --- TOTAL 5965 1929 936 1129 1051 979 1573 4373 2173 2183 2415 3608 MEAN 192 64.3 30.2 36.4 37.5 31.6 52.4 141 72.4 70.4 77.9 120 MAX 467 273 35 132 75 62 329 628 173 142 142 260 MIN 84 31 27 28 30 24 25 34 36 43 47 65 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1984 - 2001, BY WATER YEAR (WY) MEAN 202 128 73.2 58.8 50.8 48.5 81.7 166 117 75.5 97.0 189 MAX 427 276 179 163 96.4 93.7 202 624 322 109 187 726 (WY) 1986 2000 2000 1997 1996 1999 1986 1986 1999 1989 1998 1998 MIN 81.6 53.4 30.2 33.1 29.1 23.7 28.0 43.2 42.7 38.8 47.9 61.8 (WY) 1988 1998 2001 1991 1998 1994 1994 1989 1997 1994 1993 1997 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1984 - 2001 ANNUAL TOTAL 32156 28314 ANNUAL MEAN 87.9 77.6 107 HIGHEST ANNUAL MEAN 179 1986 LOWEST ANNUAL MEAN 61.5 1994 HIGHEST DAILY MEAN 663 May 11 628 May 7 9010 Sep 22 1998 LOWEST DAILY MEAN 27 Dec 14 24 Mar 18 16 Mar 18 1994 ANNUAL SEVEN-DAY MINIMUM 28 Dec 8 24 Mar 16 17 Mar 16 1994 MAXIMUM PEAK FLOW 2560 May 6 11600 Sep 22 1998 MAXIMUM PEAK STAGE 12.89 May 6 21.69 Sep 22 1998 INSTANTANEOUS LOW FLOW 23 Mar 20 15 Mar 22 1994 10 PERCENT EXCEEDS 168 158 211 50 PERCENT EXCEEDS 58 48 67 90 PERCENT EXCEEDS 34 28 33 e Estimated 61 RIO CAMUY BASIN 50014800 RIO CAMUY NEAR BAYANEY, PR--Continued O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 62 THIS PAGE IS INTENTIONALLY BLANK 63 Figure 13. Río Grande de Arecibo basin. 64 RIO GRANDE DE ARECIBO BASIN 50020100 LAGO GARZAS NEAR ADJUNTAS, PR LOCATION.--Lat 18°08'20", long 66°44'29", Hydrologic Unit 21010002, in power gate tower of Garzas Dam on Río Vacas, 1.7 mi (2.7 km) upstream from Río Garzas, and 2.2 mi (3.5 km) southwest of Adjuntas. DRAINAGE AREA.--15.6 mi2 (40.4 km2). ELEVATION RECORDS PERIOD OF RECORD.--January 1988 to May 1989, March 1993 to current year. GAGE.--Water-stage recorder. Datum of gage is 2,400.00 ft (731.520 m) above mean sea level. Prior to May 25, 1988 at datum 2,376.80 ft (724.449 m), May 25 to July 13, 1988 at datum 2,338.08 ft (712.647 m), July 14, 1988 to May 25, 1989 at datum 2,337.82 ft (712.560 m), above mean sea level. REMARKS.--Lake is formed by earthfill dam completed in 1943. Outflow from lake controlled by vertical-lift sluice gate and fixed-crest concrete spillway. Spillway elevation, 2,415.00 ft (736.09 m).Lake is used for irrigation and power production. Operated by P.R. Electric Power Authorithy. Gage-height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 99-4143,September 1996. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,418.28 ft (737.092 m),Sept. 22, 1998; minimum elevation, 2,364.79 ft (720.788 m), Aug. 23, 1988. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 2,417.19 ft (736.76 m), May 6; minimum elevation, 2,378.41 ft (724.94 m), June 3. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 99-4143,1996) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 2,317 0 2,376 1,419 2,336 243 2,399 2,700 2,359 794 2,415 4,143 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2409.83 2414.84 2414.81 2414.76 2414.76 2414.28 2412.90 2414.32 2384.46 A 2397.41 2405.13 2 2411.49 2414.74 2414.82 2414.64 2414.41 2414.38 2412.48 2414.39 2384.80 2391.10 2397.64 2405.41 3 2412.15 2414.69 2414.81 2414.71 2414.49 2414.43 2412.57 2414.45 2385.56 2390.69 2397.27 2405.42 4 2412.68 2414.88 2414.80 2414.71 2414.62 2414.48 2412.64 2413.95 2385.71 2390.92 2397.51 2405.38 5 2414.11 2414.88 2414.80 2414.52 2414.54 2414.20 2412.72 2414.05 2386.04 2391.14 2397.72 2405.66 6 2415.03 2414.73 2414.80 2414.54 2414.59 2414.26 2413.76 A 2386.37 2390.94 2398.39 2405.57 7 2414.96 2414.89 2414.81 2414.60 2414.62 2414.33 2413.96 A 2386.00 2391.15 2398.18 2406.07 8 2414.92 2414.87 2414.81 2414.61 2414.64 2414.16 2414.09 A 2385.82 2391.36 2398.39 2406.81 9 2414.72 2414.54 2414.81 2414.64 2414.66 2414.05 2414.30 2409.80 2386.04 2390.84 2398.54 2407.17 10 2414.59 2414.45 2414.81 2414.72 2414.67 2414.15 2414.41 2404.20 2386.32 2390.77 2398.31 2407.50 11 2414.01 2414.74 2414.80 2414.75 2414.70 2414.19 2414.10 2401.57 2386.40 2391.06 2398.62 2404.73 12 2414.46 2415.03 2414.77 2414.52 2414.36 2413.86 2414.21 2398.77 A 2390.74 2398.88 2405.88 13 2414.77 2414.89 2414.79 2414.64 2414.45 2413.96 2414.38 2396.78 A 2390.71 2398.66 2406.30 14 2414.82 2414.89 2414.79 2414.66 2414.55 2413.82 2414.46 2395.01 A 2390.99 2399.14 2406.15 15 2414.82 2415.02 2414.79 2414.69 2414.30 2413.88 2413.94 2392.93 A 2391.22 2398.98 2406.50 16 2414.87 2414.63 2414.78 2414.70 2414.38 2413.66 2413.96 2392.10 A 2391.57 2399.21 2406.81 17 2414.89 2414.79 2414.78 2414.70 2414.47 2413.76 2414.05 2389.66 A 2391.12 2399.07 2406.94 18 2414.83 2414.81 2414.76 2414.43 2414.53 2413.78 2413.86 A A 2392.18 2399.28 2407.30 19 2415.01 2414.80 2414.76 2414.59 2414.61 2413.45 2413.94 A A 2392.46 2400.66 2407.53 20 2414.95 2414.80 2414.89 2414.66 2414.40 2413.58 2413.65 A A 2392.12 2400.59 2408.64 21 2414.94 2414.87 2414.79 2414.69 2414.49 2412.78 2413.94 A A 2392.46 2400.89 2410.49 22 2414.99 2414.86 2414.78 2414.69 2414.33 2412.89 2414.05 A A 2393.77 2401.04 2411.10 23 2415.01 2414.86 2414.78 2414.59 2414.39 2412.93 2414.55 A A 2393.92 2402.64 2411.54 24 2414.90 2414.86 2414.78 2414.65 2414.49 2413.02 2414.68 A A 2394.08 2403.13 2411.91 25 2414.76 2414.86 2414.78 2414.67 2414.60 2413.09 2414.38 2386.00 A 2394.32 2403.49 2412.23 26 2414.81 2414.85 2414.78 2414.68 2414.38 2413.16 2414.49 2386.34 A 2395.46 2403.81 2412.59 27 2414.84 2414.69 2414.74 2414.68 2414.41 2412.76 2414.61 2386.64 A 2395.89 2403.74 2412.97 28 2414.90 2414.79 2414.75 2414.68 2414.48 2412.85 2414.66 2387.01 A 2392.56 2403.95 2413.20 29 2415.07 2414.82 2414.75 2414.73 --- 2412.76 2414.66 2387.10 A 2395.60 2404.19 2413.49 30 2414.91 2414.84 2414.76 2414.76 --- 2412.84 2414.67 2387.45 A 2396.61 2404.39 2413.76 31 2414.92 --- 2414.76 2414.76 --- 2412.91 --- 2387.80 --- 2396.83 2404.26 --- MAX 2415.07 2415.03 2414.89 2414.76 2414.76 2414.48 2414.68 --- --- --- 2404.39 2413.76 MIN 2409.83 2414.45 2414.74 2414.43 2414.30 2412.76 2412.48 --- --- --- 2397.27 2404.73 A No gage-height record 65 RIO GRANDE DE ARECIBO BASIN 50020100 LAGO GARZAS NEAR ADJUNTAS, PR--Continued O N D 2000 J F M A M J J A S 2001 2380 2385 2390 2395 2400 2405 2410 2415 2420 ELEVATION, IN FEET Gap indicates missing record 66 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR LOCATION.--Lat 18°10'54", long 66°44'12", Hydrologic Unit 21010002, at Highway 135 bridge junction with Hwy.10, 1.4 mi (2.2 km) south from Lago Adjuntas, and 1.5 mi (2.4 km) northwest of Adjuntas plaza. DRAINAGE AREA.--12.7 mi2 (48.43 km2), this does not include 6.0 mi2 (15.6 km2) above Lago Garzas. PERIOD OF RECORD.--November 1946 to April 1950 (operated by Puerto Rico Water Resources Authority), March 2000 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,443 ft (440 m), from topographic map. REMARKS.--Records poor. Flow affected by Lago Garzas, 2.63 mi (4.23 km) and sewage treatment plant 1.1 mi (1.77 km) upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 68 99 48 e25 e22 e18 7.0 e12 12 e18 21 104 2 65 82 45 e24 e21 e21 6.8 e10 12 13 15 33 3 75 70 44 e23 e20 e14 e8.7 e9.6 19 11 14 53 4 62 74 43 e22 e19 e13 e9.0 e9.7 25 13 15 25 5 177 83 41 e22 e17 e12 e17 9.6 15 12 13 21 6 163 68 40 e21 e16 e11 e76 1240 12 11 14 42 7 198 66 40 e20 e28 e11 26 194 11 10 13 149 8 133 75 e39 e19 e18 e10 15 49 11 10 12 133 9 93 64 e38 e19 e16 e9.7 14 37 11 10 25 54 10 74 49 37 e18 e15 e9.3 11 195 e10 39 17 32 11 72 49 36 e19 e16 e9.3 11 e75 e10 e11 15 24 12 61 94 36 e19 e16 e8.9 9.7 e41 10 e26 13 181 13 62 84 e34 e19 e15 e8.5 9.3 31 10 e15 13 65 14 77 68 e33 e19 e15 e8.5 9.6 27 13 12 49 42 15 76 342 e37 e19 e15 e8.9 9.1 24 24 12 19 31 16 106 86 e36 e29 e13 e9.0 8.7 22 13 9.9 14 26 17 133 59 e34 e26 e13 e8.1 8.5 21 11 9.6 16 34 18 94 66 e33 e21 e13 e7.7 8.5 26 17 27 14 34 19 397 61 e31 e19 e12 e8.1 8.5 24 11 13 49 25 20 134 60 e32 e19 e12 e9.4 14 18 10 11 21 78 21 127 70 e39 e18 e12 9.3 26 17 10 10 16 316 22 154 65 e30 e17 e22 13 16 17 e13 90 47 94 23 130 65 e29 e19 e16 12 59 16 e20 33 121 76 24 113 56 e28 e19 e18 13 19 15 e15 20 34 45 25 89 56 e28 e17 e15 9.7 16 15 e12 14 25 36 26 78 53 e41 e16 e14 8.2 17 14 e15 98 20 94 27 84 45 e38 e18 e13 7.7 e23 15 26 32 18 65 28 147 47 e28 e30 e13 7.4 e16 16 16 17 18 39 29 202 49 e27 e34 --- 7.1 e14 14 13 19 17 32 30 134 50 e26 e34 --- 7.1 14 13 e35 19 30 29 31 108 --- e25 e24 --- 6.8 --- 12 --- 15 20 --- TOTAL 3686 2255 1096 668 455 316.7 507.4 2238.9 442 660.5 748 2012 MEAN 119 75.2 35.4 21.5 16.2 10.2 16.9 72.2 14.7 21.3 24.1 67.1 MAX 397 342 48 34 28 21 76 1240 35 98 121 316 MIN 61 45 25 16 12 6.8 6.8 9.6 10 9.6 12 21 AC-FT 7310 4470 2170 1320 902 628 1010 4440 877 1310 1480 3990 CFSM 6.36 4.02 1.89 1.15 .87 .55 .90 3.86 .79 1.14 1.29 3.59 IN. 7.33 4.49 2.18 1.33 .91 .63 1.01 4.45 .88 1.31 1.49 4.00 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1947 - 2001, BY WATER YEAR (WY) MEAN 84.6 52.1 35.7 22.2 26.2 15.6 16.7 38.0 26.4 29.6 51.0 88.6 MAX 119 75.2 40.6 29.6 56.9 21.6 30.6 72.2 36.0 49.3 94.5 129 (WY) 2001 2001 1948 1949 1950 1949 1950 2001 2000 1949 2000 2000 MIN 50.3 27.3 30.8 19.7 16.2 10.2 10.4 12.2 14.7 18.0 24.1 55.8 (WY) 1950 1950 1947 1948 2001 2001 1948 1948 2001 1947 2001 1947 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1947 - 2001 ANNUAL TOTAL 15085.5 ANNUAL MEAN 41.3 41.2 HIGHEST ANNUAL MEAN 41.4 1948 LOWEST ANNUAL MEAN 41.0 1949 HIGHEST DAILY MEAN 1510 Aug 23 1240 May 6 1510 Aug 23 2000 LOWEST DAILY MEAN 9.4 May 1 6.8 Mar 31 6.8 Mar 31 2001 ANNUAL SEVEN-DAY MINIMUM 9.7 Apr 25 7.1 Mar 27 7.1 Mar 27 2001 MAXIMUM PEAK FLOW 12000 May 6 12000 May 6 2001 MAXIMUM PEAK STAGE 15.49 May 6 15.49 May 6 2001 ANNUAL RUNOFF (AC-FT) 29920 29880 ANNUAL RUNOFF (CFSM) 2.21 2.21 ANNUAL RUNOFF (INCHES) 30.01 29.97 10 PERCENT EXCEEDS 133 85 78 50 PERCENT EXCEEDS 35 20 23 90 PERCENT EXCEEDS 13 9.8 12 e Estimated 67 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR--Continued O N D 2000 J F M A M J J A S 2001 1 2 5 10 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 68 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1969-74, 1979 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2000 to September 2001. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 2000. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,080 mg/L May 6, 2001; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 14,400 tons (13,064 tonnes) May 6, 2001; Minimum daily mean, 0.03 ton (0.03 tonne) June 1, 2, 2001. EXTREMES FOR CURRENT YEAR 2001.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,080 mg/L May 6, 2001; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 14,400 tons (13,064 tonnes) May 6, 2001; Minimum daily mean, 0.03 ton (0.03 tonne) June 1, 2, 2001. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 31... 1310 92 242 7.8 24.7 1.5 7.8 99 12 40 730 76 19.9 FEB 22... 0830 11 329 7.7 20.8 .7 7.7 91 <10 E100 360 -- -- MAY 16... 1120 22 290 7.5 25.0 .7 8.1 104 <10 E150 E120 110 29.1 SEP 20... 0930 20 390 7.2 22.7 -- 8.3 102 10 3900 270 110 29.1 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 31... 6.45 15.1 .8 1.72 82 <1.0 6.3 18.9 E.1 27.2 145 36.1 <10 FEB 22... -- -- -- -- 115 -- -- -- -- -- -- -- <10 MAY 16... 9.04 15.9 .7 1.90 103 <1.0 10.7 20.6 E.1 30.4 180 10.6 <10 SEP 20... 9.25 35.1 1 2.11 102 -- 9.4 54.1 <.2 29.5 230 12.7 <10 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) OCT 31... -- <.01 .8 .06 .36 .42 1.2 5.4 .060 <2 14.0 <18 <.11 FEB 22... 1.39 .01 1.4 .04 .24 .28 1.7 7.4 .120 -- -- -- -- MAY 16... -- <.01 .5 .02 .18 .20 .65 2.9 .050 <2 16.1 E16 <.11 SEP 20... .69 .04 .7 .01 .29 .30 1.0 4.6 .070 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 31... <1 <20.0 110 <1 17 <.14 <2.6 <.43 <31 <.01 <16 <.02 FEB 22... -- -- -- -- -- -- -- -- -- -- -- -- MAY 16... <1 <20.0 30 <1 16 <.01 <2.6 <.43 <31 <.01 <16 -- SEP 20... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 69 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR--Continued WATER-QUALITY RECORDS SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 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 68 36 6.7 99 61 16 48 4 .52 2 65 29 5.1 82 56 13 45 4 .49 3 75 41 9.9 70 51 9.7 44 4 .48 4 62 35 5.8 74 46 9.1 43 4 .46 5 177 181 413 83 41 9.2 41 4 .44 6 163 135 91 68 36 6.7 40 4 .44 7 198 184 147 66 31 5.6 40 4 .43 8 133 98 35 75 26 5.3 e39 e4 e.42 9 93 68 17 64 21 3.7 e38 e4 e.40 10 74 55 11 49 16 2.1 37 4 .40 11 72 53 11 49 11 1.4 36 4 .39 12 61 50 8.2 94 39 18 36 4 .39 13 62 42 7.1 84 38 9.7 e34 e4 e.40 14 77 40 8.3 68 4 .66 e33 e4 e.39 15 76 41 8.4 342 357 1310 e37 e4 e.39 16 106 83 33 86 73 17 e36 e4 e.39 17 133 113 72 59 55 8.7 e34 e4 e.39 18 94 61 16 66 38 6.7 e33 e4 e.39 19 397 364 2020 61 25 4.2 e31 e4 e.39 20 134 87 32 60 14 2.3 e32 e4 e.39 21 127 95 42 70 22 5.3 e39 e4 e.42 22 154 105 70 65 10 1.8 e30 e4 e.39 23 130 56 23 65 17 4.5 e29 e2 e.17 24 113 64 20 56 10 1.5 e28 e2 e.17 25 89 9 2.3 56 6 .97 e28 e2 e.17 26 78 5 1.0 53 5 .69 e41 e4 e.44 27 84 6 1.3 45 4 .44 e38 e4 e.40 28 147 125 145 47 2 .27 e28 e2 e.17 29 202 208 303 49 1 .17 e27 e2 e.17 30 134 100 38 50 3 .39 e26 e2 e.17 31 108 67 19 --- --- --- e25 e2 e.17 TOTAL 3686 --- 3622.1 2255 --- 1475.09 1096 --- 11.23 70 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 e25 e8 e.54 e22 e2 e.10 e18 e19 e1.0 2 e24 e5 e.32 e21 e2 e.10 e21 e19 e1.0 3 e23 e5 e.32 e20 e2 e.10 e14 e9 e.33 4 e22 e3 e.20 e19 e4 e.21 e13 e9 e.33 5 e22 e1 e.09 e17 e4 e.21 e12 e9 e.29 6 e21 e2 e.10 e16 e4 e.21 e11 e9 e.29 7 e20 e2 e.10 e28 e8 e.54 e11 e9 e.29 8 e19 e4 e.21 e18 e4 e.21 e10 e9 e.29 9 e19 e4 e.21 e16 e4 e.16 e9.7 e7 e.19 10 e18 e4 e.21 e15 e4 e.16 e9.3 e10 e.25 11 e19 e4 e.21 e16 e4 e.16 e9.3 e10 e.25 12 e19 e4 e.21 e16 e4 e.16 e8.9 e2 e.05 13 e19 e4 e.21 e15 e4 e.16 e8.5 e2 e.05 14 e19 e4 e.21 e15 e4 e.16 e8.5 e2 e.05 15 e19 e8 e.84 e15 e4 e.16 e8.9 e2 e.05 16 e29 e15 e2.4 e13 e4 e.13 e9.0 e10 e.25 17 e26 e15 e.59 e13 e4 e.13 e8.1 e2 e.05 18 e21 e2 e.10 e13 e4 e.13 e7.7 e4 e.07 19 e19 e4 e.21 e12 e4 e.14 e8.1 e2 e.05 20 e19 e4 e.21 e12 e4 e.14 e9.4 e11 e.30 21 e18 e4 e.21 e12 e4 e.14 9.3 10 .25 22 e17 e6 e.25 e22 e2 e.10 13 9 .33 23 e19 e4 e.21 e16 e4 e.16 12 9 .29 24 e19 e4 e.21 e18 e4 e.16 13 9 .33 25 e17 e4 e.21 e15 e4 e.16 9.7 7 .19 26 e16 e4 e.21 e14 e4 e.13 8.2 2 .05 27 e18 e4 e.21 e13 e4 e.13 7.7 4 .07 28 e30 e9 e.77 e13 e4 e.13 7.4 6 .11 29 e34 e15 e2.4 --- --- --- 7.1 4 .08 30 e34 e15 e2.4 --- --- --- 7.1 4 .07 31 e24 e15 e.59 --- --- --- 6.8 3 .06 TOTAL 668 --- 15.16 455 --- 4.58 316.7 --- 7.26 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 7.0 5 .09 e12 e6 e.19 12 1 .03 2 6.8 7 .12 e10 e6 e.16 12 1 .03 3 e8.7 e8 e.16 e9.6 e6 e.14 19 8 .84 4 e9.0 e10 e.22 e9.7 e5 e.14 25 15 2.4 5 e17 e10 e.20 9.6 5 .13 15 15 .59 6 e76 e358 e379 1240 1080 14400 12 11 .37 7 26 30 2.6 194 101 110 11 9 .28 8 15 38 1.5 49 17 2.2 11 7 .22 9 14 29 1.1 37 15 1.5 11 5 .15 10 11 27 .83 195 304 706 e10 e3 e.09 11 11 26 .73 e75 e78 e17 e10 e3 e.08 12 9.7 24 .62 e41 e32 e3.8 10 3 .07 13 9.3 19 .48 31 9 .77 10 2 .07 14 9.6 13 .35 27 8 .54 13 2 .08 15 9.1 8 .20 24 5 .32 24 14 2.0 16 8.7 7 .16 22 1 .09 13 8 .31 17 8.5 7 .15 21 2 .10 11 6 .17 18 8.5 6 .15 26 2 .17 17 10 .89 19 8.5 6 .14 24 3 .20 11 7 .21 20 14 6 .24 18 4 .21 10 6 .18 21 26 28 3.5 17 6 .25 10 6 .15 22 16 6 .27 17 7 .31 e13 e5 e.13 23 59 368 268 16 8 .34 e20 e12 e.98 24 19 19 1.0 15 9 .36 e15 e10 e.41 25 16 15 .63 15 7 .29 e12 e8 e.33 26 17 13 .57 14 6 .22 e15 e6 e.25 27 e23 e11 e.61 15 4 .16 26 17 3.0 28 e16 e10 e.36 16 2 .11 16 6 .27 29 e14 e8 e.30 14 2 .06 13 5 .18 30 14 6 .25 13 4 .13 e35 e5 e.16 31 --- --- --- 12 4 .14 --- --- --- TOTAL 507.4 --- 664.53 2238.9 --- 15246.03 442 --- 14.92 71 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 e18 e4 e.15 21 10 .55 104 228 331 2 13 4 .14 15 10 .39 33 20 1.9 3 11 5 .14 14 9 .35 53 54 23 4 13 5 .19 15 9 .38 25 21 1.5 5 12 6 .18 13 9 .31 21 8 .44 6 11 6 .18 14 9 .32 42 34 13 7 10 7 .19 13 8 .29 149 357 879 8 10 8 .21 12 8 .27 133 261 398 9 10 8 .22 25 14 1.5 54 32 4.7 10 39 432 261 17 8 .36 32 14 1.2 11 e11 e6 e.19 15 7 .29 24 8 .53 12 e26 e23 e.10 13 7 .24 181 457 834 13 e15 e10 e.47 13 6 .21 65 54 10 14 12 6 .17 49 280 127 42 25 2.9 15 12 4 .13 19 13 .81 31 12 1.0 16 9.9 2 .06 14 6 .22 26 8 .54 17 9.6 2 .05 16 5 .21 34 16 2.0 18 27 24 3.5 14 4 .15 34 18 2.1 19 13 6 .23 49 36 12 25 9 .64 20 11 5 .15 21 10 .60 78 270 205 21 10 4 .11 16 7 .28 316 390 1230 22 90 838 498 47 59 17 94 95 29 23 33 19 1.9 121 120 63 76 50 19 24 20 10 .59 34 19 1.7 45 15 1.9 25 14 7 .26 25 15 1.0 36 9 .86 26 98 435 305 20 10 .58 94 85 59 27 32 21 2.2 18 7 .35 65 51 13 28 17 11 .51 18 7 .32 39 45 4.9 29 19 8 .40 17 6 .29 32 36 3.1 30 19 5 .25 30 18 3.2 29 32 2.4 31 15 6 .24 20 8 .46 --- --- --- TOTAL 660.5 --- 1077.11 748 --- 234.63 2012 --- 4075.61 YEAR 15085.5 26448.25 e Estimated 72 RIO GRANDE DE ARECIBO BASIN 50021030 RIO PELLEJAS ABOVE CENTRAL PELLEJAS,PR LOCATION.--Lat 18°12'17',long 66°42'13",Hydrologic Unit 21010002,0.2 mi (0.3 km) southeast from Escuela Lucas Valdivieso, 3.0 mi (4.8 km) north from Adjuntas Hospital and 2.0 mi (3.2 km) west from Lago Adjuntas. DRAINAGE AREA.--2.99 mi2 (7.74 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--May 2000 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,148 ft (350 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Flow regulated by Lago Adjuntas 2.0 mi (3.2 km) west. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e49 e45 30 e34 e29 20 16 17 24 42 25 33 2 e37 e65 29 e33 e28 22 16 16 24 38 24 21 3 e37 e65 29 e33 e28 20 16 16 28 36 23 37 4 34 e60 29 e33 e27 20 17 16 33 37 22 23 5 52 e60 29 e33 e26 19 20 16 32 35 21 20 6 63 e55 28 e33 e25 18 19 232 30 32 20 40 7 e142 e50 28 31 e24 18 19 51 28 28 20 51 8 54 e40 28 e31 e24 17 17 22 28 25 19 45 9 41 e35 29 e32 e23 17 17 20 27 26 18 31 10 37 e35 29 e32 e23 17 17 62 26 51 20 20 11 52 e34 29 e30 e22 17 17 31 24 26 19 18 12 e37 e70 28 31 e22 17 16 42 23 33 19 42 13 35 e50 28 31 e22 16 16 35 23 30 18 22 14 e34 e35 29 e30 e21 16 16 39 25 29 26 20 15 e34 e37 29 e30 e21 17 16 e27 27 28 20 17 16 e115 e35 e29 e30 e22 16 16 e26 29 26 18 16 17 e91 e30 e29 e29 e21 16 15 27 28 25 17 20 18 e69 e32 e28 e28 e21 16 15 28 31 28 17 17 19 e50 e29 e29 e28 e20 16 15 28 25 26 24 16 20 e60 e29 e28 e28 e20 16 17 27 24 25 18 19 21 e110 e29 28 e27 e20 17 23 26 22 24 18 63 22 e115 e30 29 e27 e20 22 21 26 25 43 20 20 23 e110 32 30 e28 23 30 48 26 31 26 39 21 24 e90 31 33 e29 22 34 20 26 27 26 19 17 25 e85 29 34 e30 22 27 19 32 30 26 17 15 26 e65 29 37 e29 22 22 19 30 27 34 16 15 27 e60 28 37 e29 21 18 22 26 26 29 16 22 28 e55 28 35 e30 20 16 18 26 37 26 37 17 29 e60 28 e34 e31 --- 16 17 26 32 26 23 15 30 e45 31 e34 e32 --- 16 17 25 48 25 25 15 31 e40 --- e34 e30 --- 16 --- 25 --- 24 21 --- TOTAL 1958 1186 939 942 639 585 557 1072 844 935 659 748 MEAN 63.2 39.5 30.3 30.4 22.8 18.9 18.6 34.6 28.1 30.2 21.3 24.9 MAX 142 70 37 34 29 34 48 232 48 51 39 63 MIN 34 28 28 27 20 16 15 16 22 24 16 15 AC-FT 3880 2350 1860 1870 1270 1160 1100 2130 1670 1850 1310 1480 CFSM 9.25 5.79 4.43 4.45 3.34 2.76 2.72 5.06 4.12 4.42 3.11 3.65 IN. 10.66 6.46 5.11 5.13 3.48 3.19 3.03 5.84 4.60 5.09 3.59 4.07 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2001, BY WATER YEAR (WY) MEAN 63.2 39.5 30.3 30.4 22.8 18.9 18.6 34.6 42.7 33.4 27.5 37.0 MAX 63.2 39.5 30.3 30.4 22.8 18.9 18.6 34.6 57.2 36.7 33.7 49.0 (WY) 2001 2001 2001 2001 2001 2001 2001 2001 2000 2000 2000 2000 MIN 63.2 39.5 30.3 30.4 22.8 18.9 18.6 34.6 28.1 30.2 21.3 24.9 (WY) 2001 2001 2001 2001 2001 2001 2001 2001 2001 2001 2001 2001 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 2000 - 2001 ANNUAL TOTAL 11064 ANNUAL MEAN 30.3 30.3 HIGHEST ANNUAL MEAN 30.3 2001 LOWEST ANNUAL MEAN 30.3 2001 HIGHEST DAILY MEAN 142 Oct 7 232 May 6 232 May 6 2001 LOWEST DAILY MEAN 22 Aug 10 15 Apr 17 15 Apr 17 2001 ANNUAL SEVEN-DAY MINIMUM 23 Aug 8 16 Apr 13 16 Apr 13 2001 MAXIMUM PEAK FLOW 2290 May 6 2290 May 6 2001 MAXIMUM PEAK STAGE 9.42 May 6 9.42 May 6 2001 INSTANTANEOUS LOW FLOW 14 Apr 17 14 Apr 17 2001 ANNUAL RUNOFF (AC-FT) 21950 21960 ANNUAL RUNOFF (CFSM) 4.44 4.44 ANNUAL RUNOFF (INCHES) 60.26 60.30 10 PERCENT EXCEEDS 71 46 55 50 PERCENT EXCEEDS 37 27 29 90 PERCENT EXCEEDS 28 17 17 e Estimated 73 RIO GRANDE DE ARECIBO BASIN 50021030 RIO PELLEJAS ABOVE CENTRAL PELLEJAS,PR--Continued O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 74 RIO GRANDE DE ARECIBO BASIN 50021030 RIO PELLEJAS ABOVE CENTRAL PELLEJAS,PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--May 2000 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2000 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 2000. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,030 mg/L May 6, 2001; Minimum daily mean, e3 mg/L February 22, 2001. SEDIMENT LOADS: Maximum daily mean, 2,810 tons (2,549 tonnes) May 6, 2001; Minimum daily mean, e0.14 ton (e0.13 tonne) February 22 and August 27, 2001. EXTREMES FOR CURRENT YEAR 2001.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,030 mg/L May 6, 2001; Minimum daily mean, e3 mg/L February 22, 2001. SEDIMENT LOADS: Maximum daily mean, 2,810 tons (2,549 tonnes) May 6, 2001; Minimum daily mean, e0.14 ton (e0.13 tonne) February 22 and August 27, 2001. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 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 e49 e217 e69 e45 e113 e13 30 60 4.8 2 e37 e82 e8.1 e65 e358 e150 29 50 3.9 3 e37 e85 e8.6 e65 e358 e150 29 39 3.0 4 34 89 8.1 e60 e358 e150 29 29 2.3 5 52 277 103 e60 e358 e150 29 19 1.5 6 63 358 150 e55 e277 e103 28 10 .73 7 e142 e480 e488 e50 e277 e103 28 7 .56 8 54 209 32 e40 e113 e13 28 8 .60 9 41 113 13 e35 e24 e2.2 29 7 .57 10 37 91 9.3 e35 e24 e2.2 29 6 .50 11 52 211 51 e34 e23 e2.1 29 6 .44 12 e37 e49 e5.0 e70 e358 e150 28 5 .38 13 35 24 2.2 e50 e211 e51 28 4 .32 14 e34 e23 e2.1 e35 e24 e2.2 29 4 .34 15 e34 e22 e2.0 e37 e24 e2.2 29 5 .40 16 e115 e576 e458 e35 e24 e2.2 e29 e6 e.49 17 e91 e783 e274 e30 e10 e.77 e29 e6 e.44 18 e69 e358 e150 e32 e31 e2.8 e28 e5 e.38 19 e50 e277 e103 e29 e12 e.91 e29 e6 e.44 20 e60 e358 e150 e29 e11 e.89 e28 e6 e.42 21 e110 e576 e458 e29 e11 e.84 28 6 .48 22 e115 e576 e458 e30 e10 e.77 29 7 .54 23 e110 e576 e458 32 31 2.8 30 8 .68 24 e90 e783 e274 31 61 5.1 33 10 .87 25 e85 e783 e274 29 24 1.9 34 11 1.0 26 e65 e358 e150 29 14 1.1 37 13 1.2 27 e60 e358 e150 28 11 .88 37 12 1.2 28 e55 e209 e32 28 9 .67 35 11 1.1 29 e60 e358 e150 28 8 .65 e34 e11 e.99 30 e45 e113 e13 31 41 3.7 e34 e11 e.99 31 e40 e113 e13 --- --- --- e34 e11 e.99 TOTAL 1958 --- 4516.4 1186 --- 1069.88 939 --- 32.55 75 RIO GRANDE DE ARECIBO BASIN 50021030 RIO PELLEJAS ABOVE CENTRAL PELLEJAS,PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 e34 e11 e1.0 e29 e57 e4.3 20 11 .65 2 e33 e10 e.87 e28 e57 e4.3 22 37 2.2 3 e33 e10 e.87 e28 e57 e4.3 20 29 1.6 4 e33 e10 e.87 e27 e16 e1.1 20 24 1.3 5 e33 e10 e.87 e26 e18 e1.2 19 18 .94 6 e33 e10 e.87 e25 e18 e1.2 18 13 .65 7 31 10 .81 e24 e25 e2.0 18 9 .45 8 e31 e9 e.75 e24 e25 e2.0 17 6 .30 9 e32 e9 e.75 e23 e25 e2.0 17 6 .29 10 e32 e9 e.75 e23 e25 e2.0 17 7 .31 11 e30 e6 e.53 e22 e28 e1.7 17 7 .33 12 31 9 .75 e22 e28 e1.7 17 7 .33 13 31 12 1.1 e22 e28 e1.7 16 8 .34 14 e30 e14 e1.2 e21 e16 e.89 16 8 .36 15 e30 e6 e.53 e21 e16 e.89 17 9 .39 16 e30 e6 e.53 e22 e28 e1.7 16 9 .40 17 e29 e7 e.54 e21 e16 e.89 16 11 .48 18 e28 e6 e.48 e21 e16 e.89 16 10 .42 19 e28 e6 e.48 e20 e10 e.56 16 7 .31 20 e28 e6 e.48 e20 e10 e.56 16 5 .20 21 e27 e6 e.42 e20 e10 e.56 17 4 .16 22 e27 e6 e.42 e20 e3 e.14 22 22 1.7 23 e28 e6 e.48 23 25 2.0 30 58 5.2 24 e29 e7 e.54 22 34 2.0 34 97 12 25 e30 e6 e.53 22 28 1.7 27 57 4.3 26 e29 e7 e.54 22 22 1.3 22 40 2.4 27 e29 e7 e.54 21 16 .89 18 25 1.2 28 e30 e6 e.53 20 10 .56 16 16 .68 29 e31 e9 e.75 --- --- --- 16 11 .49 30 e32 e12 e1.1 --- --- --- 16 6 .24 31 e30 e14 e1.2 --- --- --- 16 4 .19 TOTAL 942 --- 22.08 639 --- 45.03 585 --- 40.81 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 16 5 .21 17 24 1.1 24 38 2.5 2 16 5 .23 16 21 .91 24 41 2.6 3 16 12 .54 16 21 .91 28 64 5.7 4 17 24 1.2 16 23 .98 33 89 8.7 5 20 33 1.8 16 23 .96 32 69 5.9 6 19 27 1.3 232 1030 2810 30 38 3.1 7 19 32 1.9 51 164 39 28 23 1.8 8 17 25 1.2 22 19 1.2 28 15 1.2 9 17 22 1.0 20 34 1.8 27 16 1.1 10 17 20 .95 62 343 175 26 18 1.2 11 17 19 .87 31 43 4.1 24 20 1.3 12 16 17 .73 42 95 17 23 22 1.3 13 16 15 .63 35 83 7.8 23 28 1.7 14 16 12 .54 39 96 10 25 35 2.3 15 16 11 .47 e27 e210 e14 27 40 3.0 16 16 13 .54 e26 e322 e17 29 41 3.2 17 15 15 .64 27 224 16 28 40 3.1 18 15 18 .74 28 67 5.0 31 63 6.1 19 15 19 .75 28 38 2.9 25 42 2.8 20 17 25 1.3 27 31 2.2 24 22 1.4 21 23 40 2.8 26 25 1.8 22 15 .88 22 21 37 2.2 26 18 1.3 25 50 3.9 23 48 366 148 26 12 .84 31 82 8.3 24 20 89 4.7 26 10 .68 27 61 4.4 25 19 75 3.8 32 375 37 30 72 6.5 26 19 65 3.3 30 386 33 27 59 4.3 27 22 50 3.1 26 103 7.0 26 51 3.5 28 18 35 1.7 26 48 3.4 37 91 11 29 17 31 1.4 26 39 2.7 32 70 6.1 30 17 28 1.3 25 33 2.3 48 100 24 31 --- --- --- 25 36 2.4 --- --- --- TOTAL 557 --- 189.84 1072 --- 3220.28 844 --- 132.88 76 RIO GRANDE DE ARECIBO BASIN 50021030 RIO PELLEJAS ABOVE CENTRAL PELLEJAS,PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 42 30 3.5 25 37 2.5 33 138 31 2 38 30 3.1 24 46 3.0 21 40 2.4 3 36 29 2.8 23 28 1.7 37 143 35 4 37 57 6.2 22 12 .71 23 43 2.7 5 35 78 7.4 21 11 .61 20 21 1.1 6 32 41 3.5 20 12 .67 40 153 57 7 28 37 2.8 20 14 .75 51 576 296 8 25 36 2.5 19 19 .98 45 362 169 9 26 36 2.6 18 25 1.3 31 68 7.6 10 51 229 84 20 27 1.5 20 22 1.2 11 26 49 3.4 19 26 1.4 18 12 .56 12 33 92 13 19 26 1.3 42 261 94 13 30 82 6.9 18 25 1.2 22 39 2.6 14 29 73 6.3 26 64 7.8 20 16 .83 15 28 59 4.5 20 74 4.0 17 8 .38 16 26 51 3.6 18 63 3.0 16 6 .26 17 25 47 3.1 17 51 2.4 20 26 2.1 18 28 57 4.5 17 40 1.8 17 18 .84 19 26 48 3.4 24 63 7.5 16 12 .48 20 25 33 2.2 18 35 1.7 19 27 1.6 21 24 20 1.3 18 33 1.7 63 508 355 22 43 162 61 20 34 2.0 20 36 2.0 23 26 53 3.8 39 402 73 21 45 3.7 24 26 49 3.4 19 9 .44 17 26 1.2 25 26 47 3.2 17 4 .17 15 16 .68 26 34 86 10 16 4 .15 15 8 .33 27 29 52 4.2 16 3 .14 22 40 4.9 28 26 27 1.9 37 91 16 17 32 1.5 29 26 22 1.5 23 65 4.9 15 21 .87 30 25 21 1.4 25 56 4.4 15 18 .72 31 24 21 1.3 21 43 2.5 --- --- --- TOTAL 935 --- 262.3 659 --- 151.22 748 --- 1077.55 YEAR 11064 10760.82 e Estimated 77 RIO GRANDE DE ARECIBO BASIN 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR LOCATION.--Lat 1814'39", long 6643'20", Hydrologic Unit 21010001,.40 mi (.64 km) southwest from Escuela Segunda Unidad Salto Arriba, 2.2 mi (3.5 km) southwest from Utuado Plaza,1.1 mi (1.8 km) west from Escuela Arenas Abajo and 1.0 mi (1.7 km) northwest from Escuela Puente Blanco. DRAINAGE AREA.--36.0 mi2 (93.24 km2). PERIOD OF RECORD.--August 1989 to May 1999, monthly measurements and peak flow above 5,000 ft3/s (142 m3/s), June 1999 to current year. GAGE.--Water-stage recorder. Elevation of gage is 508 ft (155 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 147 187 81 12 8.6 6.2 3.7 11 6.5 9.9 107 155 2 115 143 71 12 8.1 6.8 3.9 7.7 6.1 7.4 31 61 3 123 123 57 8.6 7.2 5.4 6.3 5.9 45 6.6 15 98 4 112 118 57 8.5 5.9 5.1 7.7 5.1 13 6.3 13 44 5 231 133 54 9.1 5.5 5.0 19 4.7 12 6.2 10 33 6 257 120 55 8.0 5.5 4.9 117 e1760 e7.4 5.8 12 174 7 420 106 55 6.5 7.7 4.8 46 e667 5.9 5.7 9.9 241 8 255 118 55 6.1 6.1 4.9 22 e23 5.5 5.5 8.5 233 9 181 109 54 6.0 5.8 4.6 12 e12 5.4 5.5 8.1 140 10 144 85 54 5.9 5.7 4.4 11 e451 5.2 134 9.3 66 11 150 81 53 5.9 5.9 4.3 6.7 e47 5.0 23 14 47 12 120 122 52 5.9 5.7 4.2 6.1 e7.5 5.1 12 12 283 13 112 144 53 6.0 5.5 4.2 5.2 e7.1 5.0 25 9.5 146 14 130 102 52 5.9 5.6 4.3 4.9 e8.2 5.5 8.9 24 71 15 139 389 58 5.8 5.5 4.2 4.9 e7.7 6.8 7.4 28 51 16 266 155 56 22 5.5 4.2 4.4 13 6.0 6.4 10 44 17 264 80 56 13 5.5 3.9 4.2 11 6.4 6.1 10 51 18 209 95 55 9.8 5.3 3.8 4.1 11 9.7 7.5 10 51 19 936 90 48 7.6 5.2 3.8 4.2 18 7.6 12 37 42 20 340 87 40 6.2 5.1 3.8 4.2 10 5.7 7.2 35 92 21 250 94 44 5.9 5.2 3.9 31 9.3 5.3 6.2 12 e468 22 393 101 24 5.8 6.9 5.0 27 8.9 7.1 100 17 e139 23 317 98 21 6.4 7.2 5.1 118 8.2 20 30 177 e109 24 250 90 19 6.0 7.9 5.1 48 7.5 18 20 27 e91 25 199 80 15 5.7 6.0 6.3 21 6.7 16 11 21 e78 26 157 78 32 5.6 5.4 4.0 16 6.5 17 99 33 122 27 148 74 23 6.2 5.1 3.8 e34 6.5 9.3 53 16 104 28 309 64 15 8.9 5.0 3.8 13 6.9 14 13 18 85 29 301 76 14 9.4 --- 3.8 11 6.2 7.5 11 51 56 30 256 80 11 18 --- 3.7 12 7.5 18 12 82 52 31 174 --- 12 11 --- 3.7 --- 7.8 --- 9.3 62 --- TOTAL 7405 3422 1346 259.7 169.6 141.0 628.5 3169.9 307.0 672.9 929.3 3427 MEAN 239 114 43.4 8.38 6.06 4.55 21.0 102 10.2 21.7 30.0 114 MAX 936 389 81 22 8.6 6.8 118 1760 45 134 177 468 MIN 112 64 11 5.6 5.0 3.7 3.7 4.7 5.0 5.5 8.1 33 AC-FT 14690 6790 2670 515 336 280 1250 6290 609 1330 1840 6800 CFSM 6.64 3.17 1.21 .23 .17 .13 .58 2.84 .28 .60 .83 3.17 IN. 7.65 3.54 1.39 .27 .18 .15 .65 3.28 .32 .70 .96 3.54 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1999 - 2001, BY WATER YEAR (WY) MEAN 206 167 54.0 15.2 8.45 5.58 15.3 101 53.5 26.0 92.7 174 MAX 239 220 64.6 22.0 10.8 6.62 21.0 102 90.2 31.5 135 224 (WY) 2001 2000 2000 2000 2000 2000 2001 2001 2000 2000 2000 1999 MIN 173 114 43.4 8.38 6.06 4.55 9.58 99.5 10.2 21.7 30.0 114 (WY) 2000 2001 2001 2001 2001 2001 2000 2000 2001 2001 2001 2001 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1999 - 2001 ANNUAL TOTAL 30144.4 21877.9 ANNUAL MEAN 82.4 59.9 73.6 HIGHEST ANNUAL MEAN 87.2 2000 LOWEST ANNUAL MEAN 59.9 2001 HIGHEST DAILY MEAN 2210 Aug 23 1760 May 6 2210 Aug 23 2000 LOWEST DAILY MEAN 4.1 Aug 13 3.7 Mar 30 3.7 Mar 30 2001 ANNUAL SEVEN-DAY MINIMUM 4.2 Aug 2 3.8 Mar 27 3.8 Mar 27 2001 MAXIMUM PEAK FLOW 18900 May 6 45600 Sep 22 1998 MAXIMUM PEAK STAGE 13.90 May 6 19.72 Sep 22 1998 ANNUAL RUNOFF (AC-FT) 59790 43390 53320 ANNUAL RUNOFF (CFSM) 2.29 1.66 2.04 ANNUAL RUNOFF (INCHES) 31.15 22.61 27.78 10 PERCENT EXCEEDS 230 146 195 50 PERCENT EXCEEDS 38 12 28 90 PERCENT EXCEEDS 5.7 5.0 5.5 e Estimated 78 RIO GRANDE DE ARECIBO BASIN 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR--Continued O N D 2000 J F M A M J J A S 2001 1 2 5 10 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 79 RIO GRANDE DE ARECIBO BASIN 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--June 1999 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2000 to September 2001. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 1999. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, e1,600 mg/L May 6, 2001; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, e32,200 tons (e29,210 tonnes) May 6, 2001; Minimum daily mean, 0.01 ton (0.01 tonne) April 13-15, 2001. EXTREMES FOR CURRENT YEAR 2001.-- SEDIMENT CONCENTRATION: Maximum daily mean, e1,600 mg/L May 6, 2001; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, e32,200 tons (e29,210 tonnes) May 6, 2001; Minimum daily mean, 0.01 ton (0.01 tonne) April 13-15, 2001. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 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 1 147 80 58 187 173 105 81 1 .22 2 115 13 3.9 143 31 12 71 1 .19 3 123 106 46 123 18 6.1 57 1 .15 4 112 101 31 118 13 4.0 57 1 .16 5 231 510 949 133 7 2.5 54 1 .14 6 257 551 601 120 2 .82 55 1 .15 7 420 860 1550 106 2 .57 55 1 .15 8 255 291 218 118 2 .64 55 1 .15 9 181 10 5.7 109 2 .59 54 1 .15 10 144 1 .39 85 2 .46 54 1 .15 11 150 174 96 81 2 .44 53 1 .14 12 120 10 3.6 122 95 77 52 1 .14 13 112 1 .30 144 167 95 53 1 .14 14 130 1 .35 102 2 .55 52 1 .14 15 139 1 .38 389 722 2320 58 1 .19 16 266 491 768 155 248 155 56 2 .23 17 264 412 392 80 42 8.9 56 2 .26 18 209 143 99 95 32 8.2 55 3 .48 19 936 1420 13600 90 22 5.4 48 2 .26 20 340 602 629 87 12 2.9 40 23 5.9 21 250 391 316 94 3 .77 44 96 14 22 393 588 1080 101 1 .34 24 14 .95 23 317 781 680 98 27 13 21 6 .35 24 250 560 397 90 18 5.7 19 5 .24 25 199 229 129 80 5 1.1 15 3 .13 26 157 27 11 78 3 .64 32 66 14 27 148 14 5.8 74 1 .27 23 49 3.3 28 309 517 666 64 1 .17 15 9 .38 29 301 460 563 76 1 .21 14 1 .04 30 256 216 192 80 1 .22 11 1 .03 31 174 24 11 --- --- --- 12 1 .04 TOTAL 7405 --- 23102.42 3422 --- 2828.49 1346 --- 42.95 80 RIO GRANDE DE ARECIBO BASIN 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 12 2 .05 8.6 18 .41 6.2 25 .40 2 12 2 .06 8.1 20 .43 6.8 18 .33 3 8.6 2 .04 7.2 22 .43 5.4 23 .33 4 8.5 2 .04 5.9 25 .40 5.1 30 .41 5 9.1 1 .03 5.5 28 .41 5.0 35 .47 6 8.0 1 .02 5.5 28 .42 4.9 36 .47 7 6.5 2 .03 7.7 29 .61 4.8 35 .46 8 6.1 2 .03 6.1 30 .49 4.9 35 .46 9 6.0 2 .03 5.8 30 .47 4.6 34 .42 10 5.9 2 .03 5.7 29 .46 4.4 33 .39 11 5.9 2 .03 5.9 28 .44 4.3 32 .37 12 5.9 3 .05 5.7 21 .33 4.2 31 .35 13 6.0 8 .12 5.5 14 .21 4.2 32 .37 14 5.9 13 .20 5.6 7 .10 4.3 34 .39 15 5.8 17 .27 5.5 6 .10 4.2 35 .40 16 22 59 8.7 5.5 11 .16 4.2 37 .41 17 13 23 .80 5.5 15 .22 3.9 35 .37 18 9.8 11 .29 5.3 19 .28 3.8 34 .35 19 7.6 4 .08 5.2 23 .33 3.8 32 .32 20 6.2 6 .09 5.1 28 .38 3.8 28 .29 21 5.9 9 .14 5.2 32 .45 3.9 25 .26 22 5.8 8 .12 6.9 36 .66 5.0 21 .28 23 6.4 6 .09 7.2 40 .78 5.1 17 .24 24 6.0 7 .12 7.9 44 .94 5.1 14 .19 25 5.7 34 .53 6.0 48 .78 6.3 10 .18 26 5.6 35 .53 5.4 44 .64 4.0 7 .07 27 6.2 30 .51 5.1 39 .53 3.8 11 .11 28 8.9 26 .63 5.0 33 .44 3.8 50 .52 29 9.4 24 .60 --- --- --- 3.8 48 .49 30 18 22 1.0 --- --- --- 3.7 37 .38 31 11 19 .58 --- --- --- 3.7 26 .27 TOTAL 259.7 --- 15.84 169.6 --- 12.30 141.0 --- 10.75 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 3.7 17 .17 11 44 1.2 6.5 21 .37 2 3.9 9 .10 7.7 37 .78 6.1 21 .35 3 6.3 4 .07 5.9 30 .49 45 141 70 4 7.7 4 .08 5.1 24 .33 13 26 .89 5 19 61 9.9 4.7 17 .22 12 26 .87 6 117 845 676 e1760 e1600 e32200 e7.4 e26 e.52 7 46 117 28 e667 e477 e1710 5.9 26 .42 8 22 40 3.7 e23 e20 e1.2 5.5 26 .39 9 12 4 .13 e12 e20 e.67 5.4 27 .39 10 11 2 .04 e451 e958 e4220 5.2 27 .39 11 6.7 1 .02 e47 e107 e54 5.0 28 .38 12 6.1 1 .02 e7.5 e27 e.56 5.1 28 .39 13 5.2 1 .01 e7.1 e29 e.57 5.0 28 .38 14 4.9 1 .01 e8.2 e31 e.69 5.5 27 .41 15 4.9 1 .01 e7.7 e33 e.69 6.8 24 .44 16 4.4 1 .02 13 35 1.2 6.0 20 .32 17 4.2 2 .02 11 37 1.1 6.4 16 .27 18 4.1 2 .02 11 39 1.1 9.7 12 .30 19 4.2 2 .03 18 40 2.0 7.6 8 .17 20 4.2 3 .04 10 36 .99 5.7 11 .17 21 31 52 13 9.3 31 .77 5.3 18 .25 22 27 22 2.4 8.9 25 .61 7.1 24 .48 23 118 157 148 8.2 24 .53 20 62 6.8 24 48 126 20 7.5 24 .48 18 44 2.2 25 21 83 4.6 6.7 24 .43 16 42 2.4 26 16 76 3.3 6.5 24 .42 17 71 3.5 27 e34 e70 e6.4 6.5 24 .42 9.3 61 1.5 28 13 63 2.3 6.9 23 .43 14 64 2.4 29 11 57 1.7 6.2 22 .36 7.5 46 .96 30 12 50 1.7 7.5 21 .43 18 51 4.3 31 --- --- --- 7.8 21 .44 --- --- --- TOTAL 628.5 --- 921.79 3169.9 --- 38203.11 307.0 --- 102.61 81 RIO GRANDE DE ARECIBO BASIN 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 9.9 35 .96 107 672 729 155 834 1110 2 7.4 22 .45 31 88 9.4 61 230 48 3 6.6 23 .41 15 38 1.5 98 199 93 4 6.3 30 .50 13 27 .91 44 98 12 5 6.2 41 .70 10 25 .69 33 75 6.6 6 5.8 42 .66 12 23 .74 174 396 574 7 5.7 39 .60 9.9 20 .55 241 585 1090 8 5.5 36 .53 8.5 16 .38 233 612 822 9 5.5 32 .48 8.1 12 .27 140 372 166 10 134 1080 1020 9.3 20 .54 66 191 35 11 23 85 9.0 14 29 1.1 47 140 18 12 12 24 .80 12 29 .94 283 526 1110 13 25 61 7.1 9.5 28 .73 146 316 147 14 8.9 25 .60 24 50 9.6 71 147 28 15 7.4 25 .50 28 76 9.3 51 124 17 16 6.4 25 .43 10 25 .70 44 113 13 17 6.1 25 .41 10 23 .64 51 124 19 18 7.5 25 .51 10 22 .58 51 131 19 19 12 25 .79 37 91 29 42 116 13 20 7.2 25 .49 35 118 16 92 116 44 21 6.2 25 .42 12 65 2.2 e468 e1090 e4390 22 100 224 225 17 49 3.6 e139 e264 e135 23 30 108 9.9 177 279 200 e109 e116 e53 24 20 83 4.5 27 70 5.2 e91 e43 e11 25 11 66 2.0 21 48 2.7 e78 e29 e6.1 26 99 218 236 33 99 21 122 204 148 27 53 144 33 16 46 1.9 104 194 76 28 13 49 1.7 18 35 1.7 85 100 34 29 11 41 1.2 51 121 38 56 27 4.1 30 12 33 1.1 82 332 145 52 28 4.0 31 9.3 29 .73 62 173 35 --- --- --- TOTAL 672.9 --- 1561.47 929.3 --- 1268.87 3427 --- 10245.8 YEAR 21877.9 78316.40 e Estimated 82 RIO GRANDE DE ARECIBO BASIN 50022810 RIO VIVI BELOW HACIENDA EL PROGRESO,PR LOCATION.--Lat 18°11'21',long 66°40'20",Hydrologic Unit 21010001,4.05 mi (6.52 km) east from Adjuntas Lake Dam,2.90 mi (4.66 km) south of Viví Lake Dam, 3.80 mi (6.11 km) northeast from Adjuntas Plaza, 2.76 mi (4.44 km) northwest from Escuela de San Patricio. DRAINAGE AREA.--2.99 mi2 (7.74 km2). WATER-DISCHARGE RECORD PERIOD OF RECORD.--December 2000 to September 2001. GAGE.--Water-stage recorder. Elevation of gage is 1,710 ft (521 m), from topographic map. REMARKS.--Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 3.7 3.1 2.5 2.0 3.3 3.0 7.0 7.6 35 2 3.6 3.0 2.8 1.9 2.3 2.9 4.7 6.7 7.2 3 3.5 2.9 2.1 2.0 2.1 3.5 4.0 6.3 13 4 3.5 2.7 2.0 4.9 2.0 5.6 3.6 6.0 6.5 5 3.4 2.6 2.0 3.9 1.9 4.1 3.2 5.8 5.4 6 3.4 2.6 2.0 7.8 108 3.3 3.5 5.5 9.5 7 3.3 2.6 1.9 3.4 30 3.0 3.3 5.5 23 8 3.2 2.6 1.8 2.6 15 3.0 3.2 5.5 65 9 3.2 2.5 1.8 2.5 9.7 3.0 3.1 5.4 31 10 3.1 2.4 1.7 2.1 55 2.8 26 5.1 16 11 3.1 2.5 1.7 2.2 18 2.8 4.8 5.8 12 12 3.1 2.4 1.7 1.9 9.1 2.7 20 5.0 46 13 3.0 2.3 1.7 1.9 6.8 2.7 9.2 4.7 16 14 3.1 2.3 1.7 1.9 5.7 2.9 24 21 13 15 3.0 2.3 1.7 1.8 5.0 3.1 9.8 6.8 11 16 3.0 2.2 1.7 1.7 4.6 3.0 5.6 5.0 10 17 2.9 2.2 1.6 1.6 4.3 2.9 4.6 4.7 18 18 2.8 2.2 1.6 1.6 5.4 3.6 6.5 4.4 11 19 2.7 2.2 1.6 1.6 5.1 3.0 4.1 16 9.7 20 2.7 2.1 1.9 1.6 3.9 2.8 3.6 5.1 15 21 2.6 2.1 1.8 3.0 3.7 2.9 3.4 7.8 44 22 2.6 2.3 3.4 2.8 3.7 4.2 43 18 14 23 4.2 3.4 2.8 2.9 7.5 3.6 6.0 19 44 37 24 4.0 2.9 2.6 14 3.0 3.6 3.7 12 16 15 25 4.1 2.6 2.4 3.4 2.7 3.4 8.6 8.4 8.1 11 26 4.3 2.6 2.4 2.4 6.3 3.3 4.1 21 6.5 12 27 4.4 2.9 2.1 2.3 6.9 3.5 4.6 12 6.0 22 28 4.0 3.3 2.1 2.1 2.7 3.8 17 8.4 5.5 13 29 4.0 3.8 --- 2.1 2.9 3.2 11 8.4 5.6 11 30 3.9 3.7 --- 2.0 4.2 3.1 14 7.7 8.6 11 31 3.7 2.9 --- 2.0 --- 3.0 --- 6.8 5.3 --- TOTAL --- 96.6 68.5 75.9 92.9 335.1 139.8 303.9 269.3 563.3 MEAN --- 3.12 2.45 2.45 3.10 10.8 4.66 9.80 8.69 18.8 MAX --- 3.8 3.1 14 7.8 108 17 43 44 65 MIN --- 2.6 2.1 1.6 1.6 1.9 2.7 3.1 4.4 5.4 AC-FT --- 192 136 151 184 665 277 603 534 1120 CFSM --- 1.04 .82 .82 1.04 3.62 1.56 3.28 2.91 6.28 IN. --- 1.20 .85 .94 1.16 4.17 1.74 3.78 3.35 7.01 83 RIO GRANDE DE ARECIBO BASIN 50022810 RIO VIVI BELOW HACIENDA EL PROGRESO,PR--Continued O N D 2000 J F M A M J J A S 2001 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND Gap indicates missing record 84 RIO GRANDE DE ARECIBO BASIN 50022810 RIO VIVI BELOW HACIENDA EL PROGRESO,PR--Continued WATER-QUALITY RECORD PERIOD OF RECORD.--December 23, 2000 to September 30, 2001. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: December 23, 2000 to September 30, 2001. INSTRUMENTATION.-- USDH-48 and automatic sediment sampler since 2000. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES OBSERVED FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,180 mg/L May 06, 2001; Minimum daily mean, 1 mg/L March 18-21, 2001. SEDIMENT LOADS: Maximum daily mean, 2,980 tons (2,703 tonnes) May 6, 2001; Minimum daily mean, <0.01 ton (<0.01 tonne) several days. EXTREMES OBSERVED FOR CURRENT YEAR 2001.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,840 mg/L October 22, 1998; Minimum daily mean, 1 mg/L March 18-21, 2001. SEDIMENT LOADS: Maximum daily mean, 2,980 tons (2,703 tonnes) May 6, 2001; Minimum daily mean, <0.01 ton (<0.01 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 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 --- --- --- --- --- --- --- --- --- 2 --- --- --- --- --- --- --- --- --- 3 --- --- --- --- --- --- --- --- --- 4 --- --- --- --- --- --- --- --- --- 5 --- --- --- --- --- --- --- --- --- 6 --- --- --- --- --- --- --- --- --- 7 --- --- --- --- --- --- --- --- --- 8 --- --- --- --- --- --- --- --- --- 9 --- --- --- --- --- --- --- --- --- 10 --- --- --- --- --- --- --- --- --- 11 --- --- --- --- --- --- --- --- --- 12 --- --- --- --- --- --- --- --- --- 13 --- --- --- --- --- --- --- --- --- 14 --- --- --- --- --- --- --- --- --- 15 --- --- --- --- --- --- --- --- --- 16 --- --- --- --- --- --- --- --- --- 17 --- --- --- --- --- --- --- --- --- 18 --- --- --- --- --- --- --- --- --- 19 --- --- --- --- --- --- --- --- --- 20 --- --- --- --- --- --- --- --- --- 21 --- --- --- --- --- --- --- --- --- 22 --- --- --- --- --- --- --- --- --- 23 --- --- --- --- --- --- 4.2 8 .09 24 --- --- --- --- --- --- 4.0 8 .08 25 --- --- --- --- --- --- 4.1 8 .09 26 --- --- --- --- --- --- 4.3 8 .09 27 --- --- --- --- --- --- 4.4 8 .09 28 --- --- --- --- --- --- 4.0 8 .08 29 --- --- --- --- --- --- 4.0 7 .08 30 --- --- --- --- --- --- 3.9 7 .08 31 --- --- --- --- --- --- 3.7 7 .07 TOTAL --- --- --- --- --- --- 36.6 --- 0.75 85 RIO GRANDE DE ARECIBO BASIN 50022810 RIO VIVI BELOW HACIENDA EL PROGRESO,PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 3.7 7 .07 3.1 4 .03 2.5 4 .04 2 3.6 7 .07 3.0 4 .03 2.8 6 .05 3 3.5 7 .07 2.9 4 .03 2.1 4 .02 4 3.5 7 .06 2.7 4 .03 2.0 3 .02 5 3.4 7 .06 2.6 4 .03 2.0 3 .02 6 3.4 7 .06 2.6 3 .02 2.0 3 .02 7 3.3 6 .06 2.6 3 .02 1.9 3 .01 8 3.2 6 .06 2.6 3 .02 1.8 3 .01 9 3.2 6 .05 2.5 3 .02 1.8 3 .01 10 3.1 6 .05 2.4 3 .02 1.7 2 .01 11 3.1 6 .05 2.5 3 .02 1.7 2 .01 12 3.1 6 .05 2.4 2 .02 1.7 2 .01 13 3.0 6 .05 2.3 2 .01 1.7 2 <.01 14 3.1 6 .05 2.3 2 .01 1.7 2 <.01 15 3.0 6 .05 2.3 2 .02 1.7 2 <.01 16 3.0 6 .05 2.2 3 .02 1.7 2 <.01 17 2.9 6 .04 2.2 3 .02 1.6 2 <.01 18 2.8 6 .04 2.2 3 .02 1.6 1 <.01 19 2.7 5 .04 2.2 3 .02 1.6 1 <.01 20 2.7 5 .04 2.1 3 .02 1.9 1 <.01 21 2.6 5 .04 2.1 3 .02 1.8 1 <.01 22 2.6 5 .04 2.3 3 .02 3.4 6 .07 23 3.4 8 .08 2.8 3 .02 2.9 5 .04 24 2.9 5 .04 2.6 3 .02 14 160 24 25 2.6 4 .03 2.4 3 .02 3.4 16 .16 26 2.6 4 .03 2.4 3 .02 2.4 4 .03 27 2.9 3 .03 2.1 3 .02 2.3 4 .02 28 3.3 7 .07 2.1 3 .01 2.1 4 .02 29 3.8 9 .10 --- --- --- 2.1 4 .02 30 3.7 8 .09 --- --- --- 2.0 3 .02 31 2.9 4 .03 --- --- --- 2.0 3 .02 TOTAL 96.6 --- 1.65 68.5 --- 0.58 75.9 --- 24.72 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 2.0 3 .02 3.3 8 .09 3.0 4 .03 2 1.9 3 .01 2.3 4 .03 2.9 3 .02 3 2.0 3 .02 2.1 3 .02 3.5 6 .07 4 4.9 34 1.3 2.0 2 .01 5.6 22 .56 5 3.9 13 .19 1.9 7 .04 4.1 22 .24 6 7.8 64 5.9 108 2180 2980 3.3 21 .18 7 3.4 9 .09 30 693 95 3.0 20 .16 8 2.6 8 .05 15 222 13 3.0 16 .13 9 2.5 7 .05 9.7 50 1.4 3.0 12 .10 10 2.1 7 .04 55 1420 1070 2.8 8 .06 11 2.2 6 .04 18 140 7.7 2.8 4 .03 12 1.9 6 .03 9.1 39 1.0 2.7 4 .03 13 1.9 5 .03 6.8 16 .31 2.7 6 .04 14 1.9 5 .02 5.7 4 .07 2.9 7 .05 15 1.8 4 .02 5.0 2 .03 3.1 6 .05 16 1.7 4 .02 4.6 2 .02 3.0 5 .04 17 1.6 4 .02 4.3 2 .02 2.9 3 .03 18 1.6 3 .01 5.4 11 .22 3.6 7 .09 19 1.6 3 .01 5.1 18 .27 3.0 6 .04 20 1.6 2 .01 3.9 12 .13 2.8 3 .02 21 3.0 6 .08 3.7 10 .10 2.9 3 .02 22 2.8 4 .03 3.7 8 .09 4.2 11 .20 23 7.5 86 5.7 3.6 8 .08 6.0 27 .69 24 3.0 8 .07 3.6 8 .07 3.7 11 .12 25 2.7 4 .03 3.4 7 .07 8.6 64 3.1 26 6.3 51 3.0 3.3 7 .06 4.1 11 .13 27 6.9 44 1.9 3.5 7 .06 4.6 15 .26 28 2.7 5 .04 3.8 6 .06 17 316 78 29 2.9 7 .08 3.2 6 .05 11 100 8.2 30 4.2 18 .42 3.1 5 .05 14 141 10 31 --- --- --- 3.0 4 .04 --- --- --- TOTAL 92.9 --- 19.23 335.1 --- 4170.09 139.8 --- 102.69 86 RIO GRANDE DE ARECIBO BASIN 50022810 RIO VIVI BELOW HACIENDA EL PROGRESO,PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 7.0 29 .60 7.6 14 .37 35 809 545 2 4.7 14 .18 6.7 10 .18 7.2 36 .76 3 4.0 12 .13 6.3 7 .13 13 119 17 4 3.6 11 .13 6.0 8 .13 6.5 13 .24 5 3.2 11 .11 5.8 8 .13 5.4 13 .18 6 3.5 9 .09 5.5 9 .13 9.5 661 53 7 3.3 8 .07 5.5 9 .13 23 388 128 8 3.2 6 .05 5.5 9 .13 65 1090 1140 9 3.1 4 .04 5.4 9 .13 31 478 109 10 26 671 313 5.1 9 .13 16 99 4.3 11 4.8 26 .38 5.8 15 .30 12 60 1.9 12 20 355 64 5.0 5 .07 46 816 686 13 9.2 55 2.0 4.7 3 .03 16 44 2.1 14 24 588 187 21 890 180 13 14 .52 15 9.8 50 1.5 6.8 29 .61 11 15 .45 16 5.6 19 .29 5.0 10 .14 10 14 .38 17 4.6 12 .15 4.7 8 .10 18 181 21 18 6.5 26 .68 4.4 8 .10 11 34 1.0 19 4.1 11 .13 16 301 65 9.7 25 .64 20 3.6 9 .09 5.1 23 .33 15 398 34 21 3.4 7 .07 7.8 61 4.3 44 967 612 22 43 1140 643 18 482 104 14 139 5.4 23 19 170 17 44 668 185 37 808 368 24 12 63 2.2 16 137 14 15 61 2.6 25 8.4 46 1.1 8.1 42 .92 11 21 .65 26 21 376 115 6.5 22 .38 12 41 1.4 27 12 80 2.6 6.0 30 .49 22 361 91 28 8.4 44 1.0 5.5 53 .78 13 76 2.9 29 8.4 30 .70 5.6 26 .39 11 52 1.6 30 7.7 18 .38 8.6 60 3.3 11 51 1.5 31 6.8 7 .13 5.3 15 .22 --- --- --- TOTAL 303.9 --- 1353.80 269.3 --- 562.05 563.3 --- 3832.52 YEAR 1981.9 10068.08 < Actual value is known to be less than the value shown 87 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR LOCATION.--Lat 18°18'07", long 66°42'15", Hydrologic Unit 21010001, 2.4 mi (3.9 km) north of Utuado Plaza, 3.4 mi (5.5 km) southwest from Lago Dos Bocas Dam, 3.5 mi (5.6 km) northwest from Lago Caonillas Dam. DRAINAGE AREA.--65.62 mi2 (170 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--April 1996 to September 1998, June 1999 to current year. GAGE.--Water-stage recorder. Elevation of gage is 295.28 ft (90 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 185 263 128 69 62 53 27 42 75 102 145 358 2 161 220 115 68 61 61 31 35 58 70 112 205 3 179 206 111 65 58 42 32 31 81 58 154 192 4 156 189 108 63 54 39 38 29 79 58 107 161 5 290 196 103 62 50 37 94 25 102 56 72 113 6 330 186 102 61 47 36 149 1690 62 47 90 265 7 688 174 101 57 76 34 98 889 51 40 70 295 8 435 180 99 56 53 33 66 307 47 34 58 313 9 277 174 96 54 47 32 46 413 42 32 52 262 10 199 156 94 53 46 31 41 701 38 249 81 194 11 201 153 93 54 47 31 38 418 36 165 102 131 12 169 160 91 55 48 30 34 201 31 180 80 260 13 149 202 91 56 46 29 33 134 123 149 57 259 14 163 163 90 54 44 29 32 218 62 178 74 152 15 298 420 100 56 44 30 30 146 52 115 112 133 16 396 241 98 79 41 30 29 89 51 72 60 106 17 446 146 92 71 40 28 27 94 205 64 59 125 18 331 152 89 60 39 27 26 93 334 61 55 124 19 1140 146 85 56 38 28 25 111 142 65 87 104 20 716 144 87 54 37 31 25 87 84 47 122 121 21 580 143 104 52 38 31 42 83 62 39 66 451 22 696 155 83 50 62 40 92 112 63 117 74 234 23 710 144 80 54 47 55 134 81 115 124 255 196 24 446 146 78 54 53 63 96 68 166 82 149 297 25 307 133 77 49 46 57 195 67 104 56 112 142 26 258 128 110 48 43 40 128 75 103 96 151 184 27 255 123 101 53 40 36 e90 92 66 195 115 173 28 328 115 78 81 39 53 49 76 180 79 91 158 29 334 121 74 92 --- 33 53 60 135 77 119 101 30 322 130 72 92 --- 30 51 57 123 68 160 87 31 228 --- 70 68 --- 28 --- 134 --- 55 199 --- TOTAL 11373 5209 2900 1896 1346 1157 1851 6658 2872 2830 3240 5896 MEAN 367 174 93.5 61.2 48.1 37.3 61.7 215 95.7 91.3 105 197 MAX 1140 420 128 92 76 63 195 1690 334 249 255 451 MIN 149 115 70 48 37 27 25 25 31 32 52 87 AC-FT 22560 10330 5750 3760 2670 2290 3670 13210 5700 5610 6430 11690 CFSM 5.59 2.65 1.43 .93 .73 .57 .94 3.27 1.46 1.39 1.59 3.00 IN. 6.45 2.95 1.64 1.07 .76 .66 1.05 3.77 1.63 1.60 1.84 3.34 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1996 - 2001, BY WATER YEAR (WY) MEAN 313 317 127 96.5 70.2 54.0 67.2 156 95.1 103 182 443 MAX 490 766 242 166 102 76.7 93.3 249 130 184 393 1100 (WY) 2000 2000 2000 2000 2000 2000 2000 2000 2000 1998 1998 1998 MIN 172 84.8 53.0 39.5 46.6 33.8 46.2 50.8 40.8 36.6 77.0 87.3 (WY) 1998 1998 1998 1998 1998 1998 1997 1997 1997 1997 1997 1997 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1996 - 2001 ANNUAL TOTAL 59207 47228 ANNUAL MEAN 162 129 166 HIGHEST ANNUAL MEAN 233 2000 LOWEST ANNUAL MEAN 99.6 1997 HIGHEST DAILY MEAN 2080 Aug 23 1690 May 6 17900 Sep 22 1998 LOWEST DAILY MEAN 47 Aug 13 25 Apr 19 22 Mar 20 1998 ANNUAL SEVEN-DAY MINIMUM 50 Aug 9 28 Apr 14 23 Mar 19 1998 MAXIMUM PEAK FLOW 15000 May 6 76400 Sep 22 1998 MAXIMUM PEAK STAGE 15.45 May 6 32.92 Sep 22 1998 INSTANTANEOUS LOW FLOW 23 Apr 19 20 Mar 24 1998 ANNUAL RUNOFF (AC-FT) 117400 93680 120200 ANNUAL RUNOFF (CFSM) 2.47 1.97 2.53 ANNUAL RUNOFF (INCHES) 33.56 26.77 34.35 10 PERCENT EXCEEDS 312 259 355 50 PERCENT EXCEEDS 108 87 88 90 PERCENT EXCEEDS 61 35 39 e Estimated 88 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 89 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- April 1996 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: April 1996 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 1996. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 10,600 mg/L September 10, 1996; Minimum daily mean, 3 mg/L August 6, 1996. SEDIMENT LOADS: Maximum daily mean, 768,000 tons (e698,000 tonnes) September 22,1998; Minimum daily mean, 0.50 ton (0.45 tonne) August 6, 1996. EXTREMES FOR CURRENT YEAR 2001.-- SEDIMENT CONCENTRATION: Maximum daily mean, 5,730 mg/L October 19, 2000; Minimum daily mean, 10 mg/L November 23, 2000. SEDIMENT LOADS: Maximum daily mean, 115,000 tons (104,328 tonnes) May 6, 2001; Minimum daily mean, .91 ton (.82 tonne) April 16, 2001. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 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 1 185 110 65 263 173 141 128 14 5.0 2 161 90 39 220 42 25 115 16 5.0 3 179 132 71 206 26 14 111 18 5.3 4 156 150 63 189 21 11 108 20 5.7 5 290 463 827 196 17 8.9 103 20 5.7 6 330 404 542 186 14 6.9 102 21 5.8 7 688 1880 6740 174 15 7.0 101 22 5.9 8 435 391 517 180 17 8.1 99 22 5.8 9 277 77 58 174 18 8.6 96 20 5.2 10 199 73 39 156 20 8.3 94 18 4.7 11 201 156 103 153 19 7.9 93 50 12 12 169 113 54 160 32 15 91 86 21 13 149 37 15 202 109 69 91 87 22 14 163 34 15 163 55 24 90 89 22 15 298 307 535 420 1880 7530 100 87 24 16 396 470 1120 241 335 248 98 67 18 17 446 523 1030 146 126 50 92 45 11 18 331 387 372 152 102 42 89 27 6.5 19 1140 5730 60200 146 95 37 85 23 5.4 20 716 820 1820 144 76 29 87 22 5.2 21 580 741 1230 143 23 8.9 104 95 27 22 696 3470 12300 155 11 4.4 83 74 17 23 710 3050 11400 144 10 4.0 80 70 15 24 446 215 279 146 52 23 78 68 14 25 307 96 80 133 13 4.6 77 65 14 26 258 59 41 128 17 5.9 110 121 57 27 255 102 80 123 20 6.8 101 57 19 28 328 230 294 115 19 5.9 78 20 4.3 29 334 315 425 121 17 5.6 74 19 3.9 30 322 297 298 130 15 5.4 72 25 4.8 31 228 111 69 --- --- --- 70 31 5.9 TOTAL 11373 --- 100721 5209 --- 8365.2 2900 --- 383.1 90 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 69 36 6.7 62 36 6.0 53 58 11 2 68 36 6.5 61 40 6.6 61 79 13 3 65 35 6.1 58 44 6.9 42 71 8.0 4 63 33 5.7 54 48 6.9 39 64 6.6 5 62 32 5.4 50 50 6.8 37 57 5.7 6 61 31 5.1 47 48 6.1 36 50 4.8 7 57 30 4.7 76 94 32 34 47 4.3 8 56 29 4.4 53 192 28 33 44 3.9 9 54 31 4.5 47 159 20 32 41 3.5 10 53 32 4.6 46 114 14 31 40 3.4 11 54 34 4.9 47 67 8.5 31 53 4.4 12 55 34 5.1 48 36 4.6 30 63 5.1 13 56 31 4.8 46 35 4.4 29 58 4.5 14 54 28 4.1 44 33 4.0 29 51 4.1 15 56 25 3.8 44 32 3.7 30 45 3.6 16 79 54 15 41 29 3.2 30 39 3.2 17 71 113 22 40 23 2.5 28 37 2.9 18 60 100 16 39 16 1.7 27 35 2.6 19 56 85 13 38 11 1.2 28 34 2.5 20 54 65 9.4 37 11 1.0 31 32 2.7 21 52 43 6.1 38 13 1.4 31 31 2.7 22 50 27 3.6 62 67 12 40 31 3.3 23 54 27 3.9 47 61 7.8 55 31 4.5 24 54 28 4.1 53 58 8.2 63 47 9.0 25 49 30 3.9 46 55 6.9 57 53 8.3 26 48 31 4.0 43 53 6.1 40 43 4.6 27 53 30 4.3 40 50 5.4 36 29 2.8 28 81 64 15 39 45 4.7 53 62 13 29 92 78 23 --- --- --- 33 80 7.1 30 92 55 14 --- --- --- 30 67 5.4 31 68 32 5.8 --- --- --- 28 62 4.8 TOTAL 1896 --- 239.5 1346 --- 220.6 1157 --- 165.3 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 27 59 4.4 42 236 27 75 125 26 2 31 56 4.6 35 262 25 58 47 7.4 3 32 52 4.5 31 278 23 81 102 43 4 38 49 5.1 29 256 20 79 245 55 5 94 162 100 25 231 16 102 121 41 6 149 476 252 1690 5090 115000 62 56 9.4 7 98 131 46 889 1040 5990 51 49 6.8 8 66 51 9.3 307 171 139 47 43 5.4 9 46 28 3.5 413 398 852 42 38 4.3 10 41 24 2.7 701 1320 5320 38 34 3.5 11 38 26 2.6 418 458 642 36 30 2.9 12 34 27 2.5 201 61 35 31 27 2.3 13 33 27 2.4 134 29 11 123 171 178 14 32 21 1.8 218 253 355 62 67 12 15 30 15 1.3 146 141 57 52 35 5.0 16 29 12 .91 89 72 17 51 34 4.6 17 27 19 1.4 94 54 14 205 363 630 18 26 26 1.8 93 44 11 334 576 1440 19 25 34 2.3 111 48 14 142 194 80 20 25 40 2.7 87 52 12 84 158 36 21 42 38 4.3 83 56 13 62 151 25 22 92 89 31 112 108 46 63 143 24 23 134 171 109 81 83 18 115 168 64 24 96 104 31 68 55 10 166 205 127 25 195 338 610 67 41 7.4 104 156 43 26 128 187 104 75 39 7.9 103 95 28 27 e90 e251 e61 92 82 31 66 48 8.6 28 49 235 31 76 38 8.2 180 203 204 29 53 220 31 60 32 5.1 135 149 66 30 51 212 29 57 31 4.8 123 101 40 31 --- --- --- 134 143 144 --- --- --- TOTAL 1851 --- 1493.11 6658 --- 128875.4 2872 --- 3222.2 91 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 102 92 27 145 228 201 358 569 940 2 70 40 7.5 112 192 60 205 240 143 3 58 44 6.9 154 249 185 192 198 135 4 58 51 8.1 107 109 38 161 166 74 5 56 59 8.9 72 67 13 113 99 30 6 47 64 8.2 90 90 32 265 344 537 7 40 62 6.8 70 96 18 295 393 516 8 34 60 5.5 58 97 15 313 427 543 9 32 57 4.9 52 107 15 262 325 250 10 249 407 880 81 122 35 194 276 144 11 165 202 106 102 114 61 131 133 47 12 180 333 276 80 72 17 260 390 671 13 149 320 151 57 23 3.6 259 336 294 14 178 259 289 74 42 17 152 76 31 15 115 122 40 112 120 40 133 54 19 16 72 71 14 60 62 10 106 44 13 17 64 55 9.6 59 38 6.1 125 36 12 18 61 46 7.5 55 36 5.3 124 35 12 19 65 36 6.4 87 85 28 104 35 9.8 20 47 26 3.4 122 246 80 121 89 49 21 39 18 1.9 66 241 43 451 1030 2850 22 117 138 156 74 203 40 234 315 232 23 124 319 107 255 303 251 196 220 127 24 82 299 66 149 164 81 297 460 806 25 56 203 31 112 107 33 142 146 58 26 96 153 86 151 174 108 184 200 129 27 195 236 167 115 173 54 173 205 102 28 79 177 39 91 128 32 158 262 118 29 77 137 28 119 140 75 101 91 25 30 68 121 22 160 165 79 87 71 17 31 55 111 17 199 275 240 --- --- --- TOTAL 2830 --- 2587.6 3240 --- 1916.0 5896 --- 8933.8 YEAR 47228 257122.81 e Estimated 92 RIO GRANDE DE ARECIBO BASIN 50025000 RIO GRANDE DE ARECIBO NEAR UTUADO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°18'11", long 66°41'59", at bridge near Highway 10 at km 56.4, 0.5 mi (0.8 km) downstream from Río de Caguana, and 2.5 mi (4.0 km) north of Utuado plaza. DRAINAGE AREA.--66.0 mi2 (170.9 km2) this excludes 6.0 mi2 (15.5 km2) upstream from Lago Garzas to Río Guayanes in the Río Tallaboa basin. PERIOD OF RECORD.--Water years 1959-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) NOV 01... 1115 250 230 7.0 25.9 9.0 7.7 96 <10 E1300 370 86 22.9 FEB 26... 1300 50 298 7.7 24.7 8.5 8.4 102 <10 E600 E30 -- -- MAY 10... 0930 191 239 7.2 24.3 50 7.5 91 <10 4600 5700 93 26.3 AUG 22... 1100 89 256 7.0 24.7 -- 7.2 89 <10 4800 680 100 28.2 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) NOV 01... 6.98 12.3 .6 1.68 -- <1.0 17.6 9.5 E.1 30.2 148 100 24 FEB 26... -- -- -- -- 93 -- -- -- -- -- -- -- <10 MAY 10... 6.69 10.5 .5 2.61 80 <1.0 19.6 12.5 E.1 21.4 147 75.8 48 AUG 22... 8.11 12.8 .5 1.90 87 -- 25.3 13.0 E.1 27.5 169 40.6 36 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) NOV 01... 1.09 .01 1.1 .07 .27 .34 1.4 6.4 .070 <2 35.1 E10 <.11 FEB 26... .96 .04 1.0 .07 .24 .31 1.3 5.8 .100 -- -- -- -- MAY 10... 1.09 .01 1.1 .04 .39 .43 1.5 6.8 .090 <2 65.5 E17 <.11 AUG 22... .86 .03 .9 .04 .17 .21 1.1 4.9 .060 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 01... M <20.0 750 1 54 <.14 <2.6 <.43 <31 <.01 <16 <.02 FEB 26... -- -- -- -- -- -- -- -- -- -- -- -- MAY 10... M <20.0 1390 2 90 <.01 <2.6 <.43 <31 <.01 <16 <.04 AUG 22... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 93 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR LOCATION.--Lat 1812'48", long 6633'49", Hydrologic Unit 21010002, 2.0 mi (3.2 km) southeast of Jayuya, 1.4 mi (2.2 km) northeast of Hacienda Gripiñas. DRAINAGE AREA.--9.25 mi2 (23.96 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1989 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,706 ft (520 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 45 123 18 8.9 8.6 5.9 6.3 9.0 8.6 26 31 43 2 51 118 16 8.5 10 7.0 6.5 9.0 8.0 18 21 32 3 83 92 16 8.4 7.9 5.6 6.4 8.1 56 15 64 65 4 60 60 15 8.1 7.1 5.2 6.8 7.7 40 14 35 37 5 45 48 15 7.9 6.8 4.9 10 7.1 16 13 23 26 6 47 41 15 7.7 6.3 5.1 11 165 10 12 22 37 7 60 37 14 7.6 6.2 4.9 7.9 134 9.2 11 20 29 8 77 34 14 7.3 6.1 4.7 7.3 36 10 10 17 95 9 59 32 14 7.4 5.7 4.3 7.7 28 10 9.9 16 61 10 58 29 14 7.2 5.5 4.2 6.7 55 9.8 15 15 42 11 51 28 13 7.1 5.9 4.6 7.5 32 9.8 36 15 33 12 43 76 13 7.1 5.9 4.4 6.6 20 10 74 14 28 13 37 46 13 7.0 5.7 4.3 6.3 16 9.8 28 13 25 14 33 33 13 6.8 5.7 4.3 6.1 14 10 265 24 23 15 30 30 16 6.8 5.9 4.3 5.7 13 11 102 16 23 16 54 28 14 8.7 5.6 4.2 5.6 12 11 40 13 20 17 38 26 14 8.6 5.5 4.0 5.3 11 24 29 14 64 18 32 24 13 6.6 5.1 3.9 5.2 12 17 31 14 39 19 31 23 12 6.3 4.9 4.0 5.1 15 14 25 19 29 20 33 22 12 6.1 4.8 4.2 e5.1 9.8 11 20 17 126 21 32 22 11 5.9 4.8 5.2 e6.5 9.0 10 18 13 68 22 64 21 11 5.7 7.2 10 8.0 8.6 18 34 62 56 23 90 22 11 6.5 11 34 9.3 8.3 31 27 189 175 24 55 21 10 6.3 12 89 e9.0 8.2 e17 24 37 89 25 63 19 11 5.6 15 23 7.7 8.1 16 19 32 e60 26 43 18 11 5.4 8.9 11 70 7.5 14 20 28 e50 27 49 18 12 6.2 6.8 10 33 11 10 19 23 e40 28 43 17 10 7.2 6.1 8.0 13 7.6 26 15 21 e34 29 53 17 9.4 15 --- 7.5 10 8.8 20 20 19 e30 30 41 20 11 17 --- 7.1 9.4 10 51 21 23 e25 31 32 --- 9.7 8.5 --- 6.6 --- 10 --- 16 43 --- TOTAL 1532 1145 401.1 239.4 197.0 305.4 311.0 710.8 518.2 1026.9 913 1504 MEAN 49.4 38.2 12.9 7.72 7.04 9.85 10.4 22.9 17.3 33.1 29.5 50.1 MAX 90 123 18 17 15 89 70 165 56 265 189 175 MIN 30 17 9.4 5.4 4.8 3.9 5.1 7.1 8.0 9.9 13 20 AC-FT 3040 2270 796 475 391 606 617 1410 1030 2040 1810 2980 CFSM 5.34 4.13 1.40 .83 .76 1.07 1.12 2.48 1.87 3.58 3.18 5.42 IN. 6.16 4.60 1.61 .96 .79 1.23 1.25 2.86 2.08 4.13 3.67 6.05 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 2001, BY WATER YEAR (WY) MEAN 43.7 32.7 16.4 17.4 15.7 11.2 20.5 36.7 23.5 17.1 28.7 96.4 MAX 72.0 91.5 39.3 48.1 44.4 17.8 46.8 98.6 41.5 50.9 74.5 365 (WY) 1996 2000 2000 1992 1996 1998 1998 1995 1999 1996 1998 1996 MIN 11.6 10.0 5.41 4.13 4.67 4.79 5.95 5.35 5.30 2.83 9.82 10.8 (WY) 1992 1994 1998 1995 1994 1994 1994 1990 1997 1994 1994 1994 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1989 - 2001 ANNUAL TOTAL 10330.8 8803.8 ANNUAL MEAN 28.2 24.1 30.0 HIGHEST ANNUAL MEAN 64.0 1996 LOWEST ANNUAL MEAN 10.9 1994 HIGHEST DAILY MEAN 436 Sep 18 265 Jul 14 4700 Sep 10 1996 LOWEST DAILY MEAN 4.7 Aug 21 3.9 Mar 18 2.3 Jul 27 1994 ANNUAL SEVEN-DAY MINIMUM 5.6 Aug 7 4.1 Mar 14 2.5 Jul 23 1994 MAXIMUM PEAK FLOW 2640 Jul 14 18500 Sep 21 1998 MAXIMUM PEAK STAGE 10.39 Jul 14 20.00 Sep 21 1998 INSTANTANEOUS LOW FLOW 3.2 Mar 17 2.1 Jul 26 1994 ANNUAL RUNOFF (AC-FT) 20490 17460 21700 ANNUAL RUNOFF (CFSM) 3.05 2.61 3.24 ANNUAL RUNOFF (INCHES) 41.55 35.41 44.00 10 PERCENT EXCEEDS 60 55 57 50 PERCENT EXCEEDS 14 14 13 90 PERCENT EXCEEDS 6.3 5.7 4.9 e Estimated 94 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR--Continued O N D 2000 J F M A M J J A S 2001 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 95 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--October 1989 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2000 to September 2001. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since October 2000. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 693 mg/L July 14, 2001; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 2,480 tons (2,250 tonnes) July 14, 2001; Minimum daily mean, 0.01 ton (0.01 tonne) March 19, 2001. EXTREMES FOR CURRENT YEAR 2001.-- SEDIMENT CONCENTRATION: Maximum daily mean, 693 mg/L July 14, 2001; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 2,480 tons (2,250 tonnes) July 14, 2001; Minimum daily mean, 0.01 ton (0.01 tonne) March 19, 2001. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 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 45 79 9.6 123 199 304 18 25 1.2 2 51 79 11 118 139 58 16 28 1.2 3 83 142 49 92 117 30 16 31 1.3 4 60 26 4.7 60 87 14 15 34 1.4 5 45 8 .95 48 65 8.5 15 37 1.5 6 47 25 4.7 41 43 4.9 15 30 1.2 7 60 81 20 37 33 3.3 14 20 .77 8 77 97 27 34 28 2.5 14 10 .39 9 59 63 10 32 22 1.9 14 7 .27 10 58 66 13 29 17 1.3 14 7 .24 11 51 52 7.2 28 12 .90 13 6 .20 12 43 20 2.5 76 101 63 13 10 .35 13 37 5 .50 46 40 5.4 13 15 .53 14 33 5 .44 33 3 .31 13 11 .38 15 30 5 .40 30 4 .29 16 7 .30 16 54 64 20 28 3 .22 14 6 .23 17 38 27 2.9 26 3 .21 14 6 .24 18 32 13 1.2 24 3 .20 13 7 .23 19 31 11 1.1 23 4 .26 12 7 .23 20 33 18 1.8 22 5 .33 12 7 .24 21 32 31 2.7 22 7 .39 11 8 .24 22 64 85 38 21 6 .34 11 8 .23 23 90 121 50 22 5 .28 11 8 .22 24 55 61 9.8 21 4 .20 10 7 .19 25 63 55 13 19 6 .29 11 7 .19 26 43 39 4.6 18 9 .44 11 6 .19 27 49 45 7.7 18 12 .57 12 8 .27 28 43 27 3.7 17 15 .71 10 11 .29 29 53 45 13 17 18 .85 9.4 13 .34 30 41 25 3.1 20 22 1.2 11 12 .35 31 32 9 .78 --- --- --- 9.7 10 .26 TOTAL 1532 --- 334.37 1145 --- 504.79 401.1 --- 15.17 96 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 8.9 8 .18 8.6 4 .09 5.9 2 .03 2 8.5 5 .13 10 4 .10 7.0 2 .04 3 8.4 6 .13 7.9 3 .07 5.6 2 .03 4 8.1 6 .14 7.1 3 .06 5.2 2 .03 5 7.9 7 .15 6.8 2 .05 4.9 2 .03 6 7.7 8 .16 6.3 2 .04 5.1 3 .04 7 7.6 8 .17 6.2 4 .06 4.9 4 .06 8 7.3 9 .17 6.1 6 .10 4.7 5 .07 9 7.4 8 .15 5.7 8 .13 4.3 6 .08 10 7.2 6 .12 5.5 7 .11 4.2 8 .09 11 7.1 4 .08 5.9 6 .09 4.6 6 .08 12 7.1 4 .08 5.9 4 .06 4.4 4 .05 13 7.0 4 .08 5.7 2 .03 4.3 2 .03 14 6.8 4 .07 5.7 2 .04 4.3 3 .03 15 6.8 4 .07 5.9 3 .05 4.3 3 .04 16 8.7 4 .08 5.6 3 .05 4.2 4 .04 17 8.6 3 .07 5.5 3 .05 4.0 3 .03 18 6.6 2 .04 5.1 4 .05 3.9 2 .02 19 6.3 2 .03 4.9 4 .05 4.0 1 .01 20 6.1 2 .03 4.8 4 .05 4.2 3 .03 21 5.9 2 .03 4.8 4 .05 5.2 6 .08 22 5.7 3 .04 7.2 4 .08 10 10 .31 23 6.5 3 .06 11 10 .48 34 39 7.0 24 6.3 4 .07 12 9 .29 89 150 161 25 5.6 4 .06 15 12 .51 23 17 1.4 26 5.4 4 .06 8.9 5 .12 11 2 .05 27 6.2 4 .07 6.8 3 .05 10 4 .12 28 7.2 4 .08 6.1 2 .03 8.0 8 .17 29 15 9 .45 --- --- --- 7.5 7 .15 30 17 10 .58 --- --- --- 7.1 5 .11 31 8.5 4 .10 --- --- --- 6.6 4 .06 TOTAL 239.4 --- 3.73 197.0 --- 2.94 305.4 --- 171.31 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 6.3 3 .05 9.0 10 .24 8.6 2 .05 2 6.5 3 .05 9.0 8 .20 8.0 2 .04 3 6.4 3 .05 8.1 6 .14 56 59 31 4 6.8 3 .06 7.7 6 .13 40 49 14 5 10 4 .10 7.1 6 .12 16 13 .63 6 11 4 .12 165 518 1360 10 5 .14 7 7.9 5 .10 134 262 199 9.2 4 .09 8 7.3 5 .10 36 18 1.8 10 3 .10 9 7.7 5 .10 28 4 .30 10 3 .08 10 6.7 5 .09 55 59 22 9.8 4 .09 11 7.5 5 .10 32 29 2.7 9.8 4 .11 12 6.6 5 .09 20 6 .37 10 5 .13 13 6.3 5 .08 16 1 .04 9.8 5 .14 14 6.1 5 .08 14 1 .04 10 6 .16 15 5.7 5 .08 13 2 .06 11 6 .17 16 5.6 5 .07 12 2 .08 11 6 .18 17 5.3 5 .07 11 3 .10 24 26 2.8 18 5.2 5 .07 12 4 .13 17 18 .80 19 5.1 5 .07 15 5 .18 14 17 .62 20 e5.1 e5 e.07 9.8 4 .12 11 16 .49 21 e6.5 e5 e.09 9.0 4 .09 10 13 .38 22 8.0 5 .11 8.6 3 .07 18 18 1.2 23 9.3 5 .13 8.3 3 .06 31 36 6.6 24 e9.0 e5 e.12 8.2 3 .06 e17 e16 e.80 25 7.7 5 .10 8.1 2 .06 16 16 .75 26 70 136 139 7.5 2 .05 14 16 .63 27 33 43 6.2 11 7 .30 10 8 .23 28 13 13 .46 7.6 5 .11 26 28 4.6 29 10 12 .32 8.8 2 .05 20 17 .89 30 9.4 11 .28 10 2 .05 51 64 21 31 --- --- --- 10 2 .05 --- --- --- TOTAL 311.0 --- 148.41 710.8 --- 1588.70 518.2 --- 88.90 97 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 26 22 1.6 31 31 6.4 43 48 9.0 2 18 13 .61 21 11 .64 32 31 2.7 3 15 8 .34 64 91 39 65 323 242 4 14 4 .16 35 36 3.5 37 36 3.7 5 13 4 .12 23 26 1.7 26 13 .96 6 12 4 .13 22 20 1.1 37 34 8.2 7 11 5 .14 20 15 .77 29 22 1.7 8 10 5 .13 17 10 .46 95 215 200 9 9.9 5 .12 16 6 .23 61 68 12 10 15 14 .71 15 4 .15 42 41 4.7 11 36 45 14 15 4 .15 33 23 2.1 12 74 127 80 14 3 .13 28 8 .60 13 28 26 3.1 13 3 .10 25 3 .22 14 265 693 2480 24 21 3.8 23 4 .22 15 102 160 57 16 11 .50 23 4 .24 16 40 18 2.2 13 4 .13 20 4 .22 17 29 4 .31 14 3 .12 64 85 45 18 31 17 1.8 14 3 .13 39 35 3.9 19 25 10 .71 19 14 .87 29 7 .54 20 20 5 .26 17 8 .40 126 128 105 21 18 4 .21 13 4 .14 68 71 16 22 34 36 7.6 62 115 142 56 65 14 23 27 11 .76 189 345 320 175 422 549 24 24 2 .17 37 3 .27 89 112 30 25 19 3 .16 32 15 1.9 e60 e68 e12 26 20 4 .20 28 24 1.9 e50 e48 e9.0 27 19 3 .18 23 13 .81 e40 e41 e4.7 28 15 3 .11 21 6 .33 e34 e23 e2.1 29 20 2 .10 19 5 .26 e30 e8 e.60 30 21 1 .07 23 12 1.0 e25 e3 e.22 31 16 2 .09 43 59 18 --- --- --- TOTAL 1026.9 --- 2653.09 913 --- 546.89 1504 --- 1280.62 YEAR 8803.8 7338.92 e Estimated 98 RIO GRANDE DE ARECIBO BASIN 50025850 RIO JAUCA AT PASO PALMA, PR LOCATION.--Lat 18°12'50", long 66°38'44", Hydrologic Unit 21010001, 5.13 mi (8.2 km) southeast from Utuado Plaza,4.5 mi (7.24 km) south of Lago Caonillas Dam and 6.15 mi (9.89 km) northeast from Adjuntas plaza. DRAINAGE AREA.--6.89 mi2 (17.84 km2). PERIOD OF RECORD.--May 2000 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,197 ft (365 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 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 54 38 16 7.8 5.2 4.7 4.4 9.0 6.3 15 9.8 49 2 40 e40 14 7.6 5.6 5.9 4.3 6.3 6.2 11 9.6 21 3 38 e34 14 7.6 5.1 4.7 4.5 5.6 6.1 9.7 9.3 20 4 33 e30 13 7.7 5.0 4.4 5.1 5.5 8.5 8.9 9.3 18 5 32 e30 13 7.5 4.9 4.3 9.6 5.2 12 8.8 8.5 16 6 53 e27 12 7.2 4.9 4.2 8.9 193 9.4 8.4 8.4 22 7 59 e25 12 7.0 5.2 4.1 8.1 104 8.3 7.9 8.4 31 8 48 e25 12 6.9 5.2 4.0 5.9 29 7.6 7.5 7.9 56 9 38 23 11 6.6 5.0 3.9 7.1 20 7.4 7.1 7.9 64 10 33 22 11 6.4 4.7 3.8 5.5 95 6.8 13 7.5 34 11 52 21 11 6.4 4.9 3.7 5.4 29 6.9 10 7.9 25 12 40 51 11 6.3 4.9 3.7 4.9 17 6.5 18 8.1 55 13 32 31 11 6.2 4.9 3.7 4.8 13 6.4 19 6.9 27 14 28 24 10 6.2 4.8 3.8 4.9 11 6.8 38 32 23 15 27 27 11 6.1 5.0 3.7 4.6 10 6.9 20 14 22 16 45 25 11 6.1 4.8 3.7 4.4 9.2 7.3 11 9.3 20 17 38 23 11 6.6 4.8 3.5 4.3 8.7 6.6 9.4 8.7 28 18 31 22 11 5.9 4.7 3.5 4.2 9.0 7.4 9.8 9.9 24 19 28 20 10 5.7 4.7 3.5 4.3 10 6.9 8.7 18 21 20 44 19 10 5.6 4.6 3.6 4.0 8.1 6.7 7.6 12 26 21 80 19 9.6 5.5 4.4 4.1 4.9 7.7 6.5 7.4 12 107 22 82 18 9.3 5.4 4.9 6.8 6.1 7.7 8.5 36 17 39 23 81 17 9.2 5.7 6.6 10 8.4 7.7 12 19 76 96 24 64 17 9.1 5.8 6.4 21 6.9 7.4 11 16 31 44 25 64 16 8.8 5.1 5.8 13 5.7 7.2 12 11 19 32 26 48 16 8.8 5.0 5.1 6.3 9.3 6.9 11 23 15 29 27 48 16 9.5 5.4 4.6 5.7 e24 7.2 7.7 19 14 30 28 42 15 8.5 6.0 4.5 4.9 e7.6 8.0 19 12 13 27 29 43 15 8.2 6.4 --- 4.7 7.4 7.3 17 11 13 24 30 42 19 8.0 7.4 --- 4.8 8.4 6.8 22 11 13 23 31 36 --- 8.0 5.3 --- 4.5 --- 6.6 --- 9.7 13 --- TOTAL 1423 725 332.0 196.4 141.2 166.2 197.9 678.1 273.7 423.9 449.4 1053 MEAN 45.9 24.2 10.7 6.34 5.04 5.36 6.60 21.9 9.12 13.7 14.5 35.1 MAX 82 51 16 7.8 6.6 21 24 193 22 38 76 107 MIN 27 15 8.0 5.0 4.4 3.5 4.0 5.2 6.1 7.1 6.9 16 AC-FT 2820 1440 659 390 280 330 393 1350 543 841 891 2090 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2001, BY WATER YEAR (WY) MEAN 45.9 24.2 10.7 6.34 5.04 5.36 6.60 21.9 8.62 9.61 16.7 39.3 MAX 45.9 24.2 10.7 6.34 5.04 5.36 6.60 21.9 9.12 13.7 18.9 43.4 (WY) 2001 2001 2001 2001 2001 2001 2001 2001 2001 2001 2000 2000 MIN 45.9 24.2 10.7 6.34 5.04 5.36 6.60 21.9 8.11 5.54 14.5 35.1 (WY) 2001 2001 2001 2001 2001 2001 2001 2001 2000 2000 2001 2001 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 2000 - 2001 ANNUAL TOTAL 6059.8 ANNUAL MEAN 16.6 16.6 HIGHEST ANNUAL MEAN 16.6 2001 LOWEST ANNUAL MEAN 16.6 2001 HIGHEST DAILY MEAN 235 Aug 23 193 May 6 235 Aug 23 2000 LOWEST DAILY MEAN 4.0 Aug 9 3.5 Mar 17 3.5 Mar 17 2001 ANNUAL SEVEN-DAY MINIMUM 4.3 Aug 3 3.6 Mar 14 3.6 Mar 14 2001 MAXIMUM PEAK FLOW 1590 May 6 1590 May 6 2001 MAXIMUM PEAK STAGE 6.59 May 6 6.59 May 6 2001 INSTANTANEOUS LOW FLOW 3.2 Mar 17 3.2 Mar 17 2001 ANNUAL RUNOFF (AC-FT) 12020 12030 10 PERCENT EXCEEDS 48 38 39 50 PERCENT EXCEEDS 12 9.3 8.8 90 PERCENT EXCEEDS 5.2 4.7 4.7 e Estimated 99 RIO GRANDE DE ARECIBO BASIN 50025850 RIO JAUCA AT PASO PALMA, PR--Continued O N D 2000 J F M A M J J A S 2001 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 100 RIO GRANDE DE ARECIBO BASIN 50025850 RIO JAUCA AT PASO PALMA, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--May 2000 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October to September 2001 INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 2000. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 911 mg/L September 21, 2001; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 1,050 tons (952 tonnes) September 21, 2001; Minimum daily mean, 0.01 ton (0.01 tonne) several days. EXTREMES FOR CURRENT YEAR 2001.-- SEDIMENT CONCENTRATION: Maximum daily mean, 911 mg/L September 21; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 1,050 tons (952 tonnes) September 21; Minimum daily mean, 0.01 ton (0.01 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 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 54 235 39 38 15 1.4 16 35 1.5 2 40 126 13 e40 e73 e11 14 22 .79 3 38 139 15 e34 e108 e14 14 15 .53 4 33 105 9.5 e30 e7 e.73 13 9 .30 5 32 101 9.4 e30 e4 e.50 13 7 .22 6 53 323 100 e27 e6 e.60 12 6 .21 7 59 300 66 e25 e7 e.57 12 6 .19 8 48 179 24 e25 e7 e.51 12 5 .17 9 38 56 5.9 23 7 .42 11 5 .14 10 33 20 1.8 22 7 .40 11 4 .12 11 52 248 61 21 7 .38 11 3 .10 12 40 94 11 51 178 103 11 4 .11 13 32 25 2.2 31 82 7.5 11 2 .07 14 28 25 1.9 24 17 1.0 10 1 .03 15 27 24 1.8 27 49 3.9 11 1 .04 16 45 270 58 25 72 4.4 11 2 .05 17 38 104 11 23 12 .69 11 2 .06 18 31 90 7.8 22 11 .60 11 3 .07 19 28 36 2.7 20 11 .53 10 3 .08 20 44 329 74 19 10 .47 10 3 .08 21 80 603 267 19 9 .44 9.6 3 .08 22 82 520 227 18 12 .55 9.3 3 .08 23 81 399 124 17 16 .70 9.2 3 .08 24 64 265 47 17 20 .85 9.1 3 .08 25 64 317 75 16 17 .70 8.8 4 .09 26 48 115 16 16 13 .50 8.8 4 .09 27 48 127 23 16 8 .31 9.5 4 .10 28 42 123 14 15 4 .17 8.5 4 .10 29 43 100 15 15 4 .17 8.2 4 .10 30 42 137 15 19 34 2.4 8.0 5 .10 31 36 66 6.1 --- --- --- 8.0 3 .07 TOTAL 1423 --- 1344.1 725 --- 159.39 332.0 --- 5.83 101 RIO GRANDE DE ARECIBO BASIN 50025850 RIO JAUCA AT PASO PALMA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 7.8 3 .06 5.2 2 .02 4.7 1 .02 2 7.6 2 .05 5.6 1 .02 5.9 1 .02 3 7.6 2 .03 5.1 1 .02 4.7 1 .02 4 7.7 1 .02 5.0 2 .03 4.4 2 .02 5 7.5 1 .02 4.9 2 .03 4.3 2 .02 6 7.2 1 .03 4.9 3 .04 4.2 2 .03 7 7.0 2 .03 5.2 2 .03 4.1 3 .03 8 6.9 2 .03 5.2 2 .02 4.0 3 .03 9 6.6 2 .03 5.0 2 .02 3.9 3 .03 10 6.4 2 .03 4.7 3 .04 3.8 2 .02 11 6.4 1 .02 4.9 6 .07 3.7 2 .02 12 6.3 1 .02 4.9 7 .09 3.7 1 .01 13 6.2 2 .03 4.9 2 .02 3.7 2 .02 14 6.2 2 .04 4.8 1 .01 3.8 4 .04 15 6.1 3 .05 5.0 1 .01 3.7 6 .06 16 6.1 3 .04 4.8 1 .01 3.7 7 .07 17 6.6 2 .04 4.8 1 .01 3.5 6 .06 18 5.9 2 .03 4.7 1 .01 3.5 3 .03 19 5.7 2 .03 4.7 1 .01 3.5 1 .01 20 5.6 2 .03 4.6 1 .02 3.6 2 .02 21 5.5 2 .03 4.4 2 .02 4.1 3 .03 22 5.4 2 .03 4.9 2 .02 6.8 8 .19 23 5.7 2 .03 6.6 7 .17 10 12 .35 24 5.8 2 .03 6.4 6 .10 21 525 59 25 5.1 2 .03 5.8 4 .06 13 35 1.3 26 5.0 2 .03 5.1 3 .04 6.3 20 .34 27 5.4 4 .05 4.6 2 .03 5.7 9 .14 28 6.0 6 .09 4.5 2 .02 4.9 10 .13 29 6.4 6 .09 --- --- --- 4.7 13 .17 30 7.4 2 .05 --- --- --- 4.8 16 .20 31 5.3 6 .09 --- --- --- 4.5 7 .09 TOTAL 196.4 --- 1.21 141.2 --- 0.99 166.2 --- 62.52 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 4.4 6 .07 9.0 14 .39 6.3 2 .03 2 4.3 6 .07 6.3 7 .13 6.2 2 .03 3 4.5 6 .07 5.6 5 .08 6.1 2 .03 4 5.1 5 .07 5.5 5 .07 8.5 11 .66 5 9.6 15 .51 5.2 5 .07 12 12 .44 6 8.9 13 .34 193 370 1010 9.4 6 .14 7 8.1 13 .32 104 363 294 8.3 6 .13 8 5.9 9 .14 29 124 38 7.6 6 .12 9 7.1 8 .16 20 172 11 7.4 5 .10 10 5.5 7 .11 95 332 368 6.8 4 .07 11 5.4 5 .08 29 115 10 6.9 3 .05 12 4.9 4 .05 17 28 1.3 6.5 2 .04 13 4.8 5 .06 13 8 .29 6.4 2 .03 14 4.9 7 .09 11 5 .15 6.8 2 .03 15 4.6 9 .11 10 4 .10 6.9 1 .03 16 4.4 11 .13 9.2 4 .09 7.3 1 .03 17 4.3 11 .12 8.7 3 .08 6.6 1 .02 18 4.2 10 .12 9.0 4 .09 7.4 1 .02 19 4.3 10 .12 10 4 .11 6.9 1 .02 20 4.0 10 .10 8.1 4 .09 6.7 1 .02 21 4.9 9 .12 7.7 5 .10 6.5 1 .02 22 6.1 9 .14 7.7 5 .10 8.5 30 1.0 23 8.4 17 .50 7.7 1 .03 12 84 2.8 24 6.9 14 .26 7.4 1 .02 11 19 .62 25 5.7 12 .18 7.2 1 .02 12 29 1.2 26 9.3 40 2.4 6.9 1 .02 11 46 1.4 27 e24 e78 e8.6 7.2 3 .06 7.7 16 .34 28 e7.6 e14 e.31 8.0 6 .12 19 640 78 29 7.4 12 .23 7.3 5 .11 17 100 6.4 30 8.4 9 .22 6.8 3 .06 22 58 4.0 31 --- --- --- 6.6 2 .03 --- --- --- TOTAL 197.9 --- 15.80 678.1 --- 1734.71 273.7 --- 97.82 102 RIO GRANDE DE ARECIBO BASIN 50025850 RIO JAUCA AT PASO PALMA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 15 33 1.4 9.8 7 .18 49 373 224 2 11 21 .63 9.6 10 .27 21 62 3.3 3 9.7 11 .29 9.3 14 .36 20 49 2.6 4 8.9 7 .17 9.3 18 .45 18 41 1.9 5 8.8 6 .15 8.5 22 .50 16 31 1.3 6 8.4 5 .12 8.4 25 .57 22 64 5.6 7 7.9 5 .11 8.4 28 .64 31 147 30 8 7.5 5 .10 7.9 26 .55 56 260 127 9 7.1 5 .10 7.9 23 .48 64 354 151 10 13 114 7.8 7.5 20 .40 34 121 10 11 10 15 .45 7.9 17 .36 25 83 5.2 12 18 78 12 8.1 15 .33 55 235 122 13 19 97 6.0 6.9 13 .24 27 49 3.6 14 38 255 75 32 188 76 23 14 .78 15 20 62 3.9 14 101 4.1 22 29 1.6 16 11 46 1.4 9.3 71 1.8 20 37 1.9 17 9.4 49 1.2 8.7 45 1.1 28 81 8.0 18 9.8 52 1.4 9.9 20 .52 24 59 3.6 19 8.7 40 .96 18 44 3.3 21 41 2.0 20 7.6 22 .46 12 39 1.3 26 64 5.4 21 7.4 5 .11 12 31 1.0 107 911 1050 22 36 215 81 17 57 4.4 39 129 13 23 19 51 3.4 76 305 114 96 373 290 24 16 39 1.7 31 112 17 44 487 53 25 11 13 .42 19 45 2.3 32 450 35 26 23 82 17 15 13 .57 29 400 28 27 19 52 3.1 14 10 .35 30 172 12 28 12 15 .48 13 10 .32 27 59 4.0 29 11 7 .20 13 9 .31 24 18 1.0 30 11 6 .17 13 9 .30 23 4 .19 31 9.7 4 .12 13 8 .27 --- --- --- TOTAL 423.9 --- 221.34 449.4 --- 234.27 1053 --- 2196.97 YEAR 6059.8 6074.95 e Estimated 103 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR LOCATION.--Lat 18°13'53", long 66°38'14", Hydrologic Unit 21010001, 3.5 mi (5.6 km) south of Lago Caonillas Dam,4.8 mi (7.72km) southeast of Utuado Plaza and 2.78 mi (4.47 km) east of Lago Viví Dam. DRAINAGE AREA.--37.94 mi2 (98.26 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1995 to current year. GAGE.--Water-stage recorder. Elevation of gage is 984 ft (300 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 242 253 62 37 30 23 18 23 30 74 62 148 2 211 266 53 36 30 28 18 20 29 45 54 110 3 260 249 50 36 27 23 20 18 128 37 137 160 4 201 178 49 35 29 21 21 17 90 34 89 119 5 161 148 48 35 25 21 38 16 63 33 56 86 6 175 129 48 35 25 e20 43 527 40 29 52 113 7 238 117 47 34 25 e18 31 449 33 27 50 115 8 259 108 47 34 23 21 25 162 30 25 45 184 9 191 101 46 33 23 17 24 134 28 24 42 191 10 164 93 45 33 22 17 21 199 27 54 40 135 11 274 87 e45 33 22 17 22 160 26 55 53 100 12 176 245 45 33 21 16 20 91 25 89 45 119 13 151 153 45 33 21 16 19 67 24 104 37 91 14 133 108 44 33 21 17 18 57 26 344 73 78 15 125 98 49 32 21 16 18 50 26 207 65 76 16 286 90 47 33 21 16 17 46 26 85 41 74 17 208 81 47 36 20 16 16 42 31 62 42 132 18 161 76 45 32 20 16 16 45 52 62 45 138 19 145 72 44 31 20 17 15 58 33 57 72 95 20 259 69 43 31 20 17 15 39 25 46 55 260 21 226 67 42 30 19 17 19 36 23 43 44 301 22 336 67 40 29 24 23 25 35 47 89 56 199 23 365 64 40 32 29 53 31 34 61 76 426 319 24 282 65 39 31 32 188 28 32 55 69 142 209 25 268 59 39 29 31 65 24 31 42 51 101 132 26 209 56 42 28 26 31 69 30 44 69 136 115 27 192 55 45 32 23 27 e119 51 29 72 89 104 28 186 54 39 38 22 24 e29 50 81 48 77 94 29 172 53 38 46 --- 22 29 36 60 48 72 80 30 176 61 38 57 --- 20 28 32 127 60 73 72 31 142 --- 38 33 --- 19 --- 32 --- 44 96 --- TOTAL 6574 3322 1389 1060 672 862 836 2619 1361 2162 2467 4149 MEAN 212 111 44.8 34.2 24.0 27.8 27.9 84.5 45.4 69.7 79.6 138 MAX 365 266 62 57 32 188 119 527 128 344 426 319 MIN 125 53 38 28 19 16 15 16 23 24 37 72 AC-FT 13040 6590 2760 2100 1330 1710 1660 5190 2700 4290 4890 8230 CFSM 5.59 2.92 1.18 .90 .63 .73 .73 2.23 1.20 1.84 2.10 3.65 IN. 6.45 3.26 1.36 1.04 .66 .85 .82 2.57 1.33 2.12 2.42 4.07 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1996 - 2001, BY WATER YEAR (WY) MEAN 172 137 74.8 58.3 51.4 36.4 50.8 87.3 70.0 56.0 91.5 309 MAX 248 292 143 89.8 86.0 51.3 112 130 161 117 156 815 (WY) 1999 2000 2000 1997 1996 1996 1998 1998 1999 1996 1998 1998 MIN 72.9 44.2 21.0 19.6 24.0 25.7 17.0 29.1 16.1 15.5 47.9 33.2 (WY) 1997 1998 1998 1998 2001 1997 1997 1997 1997 1997 1996 1997 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1996 - 2001 ANNUAL TOTAL 31647 27473 ANNUAL MEAN 86.5 75.3 99.4 HIGHEST ANNUAL MEAN 137 1998 LOWEST ANNUAL MEAN 49.9 1997 HIGHEST DAILY MEAN 1010 Aug 23 527 May 6 13000 Sep 22 1998 LOWEST DAILY MEAN 22 Jul 15 15 Apr 19 10 Jul 4 1997 ANNUAL SEVEN-DAY MINIMUM 23 Jul 13 16 Mar 12 11 Jul 1 1997 MAXIMUM PEAK FLOW 5200 May 6 36000 Sep 22 1998 MAXIMUM PEAK STAGE 14.66 May 6 31.15 Sep 22 1998 INSTANTANEOUS LOW FLOW 9.5 Jul 6 1997 ANNUAL RUNOFF (AC-FT) 62770 54490 72030 ANNUAL RUNOFF (CFSM) 2.28 1.98 2.62 ANNUAL RUNOFF (INCHES) 31.03 26.94 35.61 10 PERCENT EXCEEDS 208 185 201 50 PERCENT EXCEEDS 49 45 52 90 PERCENT EXCEEDS 25 20 21 e Estimated 104 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR--Continued O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 105 RIO GRANDE DE ARECIBO BASIN 50026050 RIO CAONILLAS ABOVE LAGO CAONILLAS NEAR JAYUYA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°13'26", long 66°38'22", 300 ft (91 m) off Highway 531, 700 ft (213 m) upstream from Lago Caonillas, 3.3 mi (5.3 km) northwest of Jayuya plaza. DRAINAGE AREA.--40.4 mi2 (104.6 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 04... 1115 196 156 7.5 23.1 30 7.9 95 <10 3500 2100 57 15.0 FEB 22... 1110 27 244 7.9 23.9 .8 8.5 104 <10 250 E140 -- -- MAY 16... 1510 48 215 7.5 27.7 2.0 7.8 102 <10 E30 E40 79 21.3 SEP 20... 1245 64 173 7.3 25.4 -- 7.9 100 <10 2700 E100 65 17.4 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 04... 4.62 8.2 .5 1.50 52 <1.0 9.5 8.5 <.1 24.2 103 54.4 62 FEB 22... -- -- -- -- 92 -- -- -- -- -- -- -- <10 MAY 16... 6.25 11.0 .5 1.33 73 <1.0 14.5 11.2 E.1 23.8 133 17.1 <10 SEP 20... 5.22 9.1 .5 1.40 61 -- 10.3 8.1 <.2 22.4 110 19.1 <10 NITRO- CHRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) OCT 04... <.01 .7 .01 -- <.20 -- -- .080 <2 32.0 <18 <.11 2 FEB 22... <.01 .4 .03 -- <.20 -- -- .030 -- -- -- -- -- MAY 16... <.01 2.2 .03 .24 .27 2.5 10.9 .040 <2 20.5 20 <.11 <1 SEP 20... <.01 .5 .02 -- <.20 -- -- .020 -- -- -- -- -- 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- DATE (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) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 04... <20.0 2090 M 98 <.14 <2.6 <.43 <31 <.01 <16 .02 FEB 22... -- -- -- -- -- -- -- -- -- -- -- MAY 16... <20.0 120 <1 15 <.01 <2.6 <.43 <31 <.01 <16 <.02 SEP 20... -- -- -- -- -- -- -- -- -- -- -- < -- Less than M -- Presence verified, not quantified E -- Estimated value 106 RIO GRANDE DE ARECIBO BASIN 50026140 LAGO CAONILLAS AT DAMSITE NEAR UTUADO, PR LOCATION.--Lat 18°16'43",long 66°39'24", Hydrologic Unit 21010001, at Lago Caonillas Dam on Río Caonillas, 2.9 mi (4.7 km) northeast of Plaza de Utuado, 0.3 mi (0.5 km) west from Iglesia Santa María del Monte Carmelo, and 1.8 mi (2.9 km) northwest from Hacienda Carbonell. DRAINAGE AREA.--48.4 mi2 (125.4 km2). ELEVATION RECORDS PERIOD OF RECORD.--March 1991 to current year. (March 16 to September 30, 1999, no records available due to repairs conducted by Puerto Rico Electric and Power Authority; inspections data available at District Office). Prior to October 1994, published as Lago Caonillas at Caonillas. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Caonillas was completed in 1948. The dam is a concrete gravity structure with a total length of 815 ft (248 m), a maximum height of 235 ft (72 m), and a maximum base width of 195 ft (59 m). Non-overflow sections on each abutment have a total length of 603 ft (184 m). The dam is the main unit of Caonillas Hydroelectric Project, and provides 49,000 acre-feet (60 hm3) of usable storage for power generation at Caonillas Power Plant No. 1 located 2.5 mi (4.0 km) downstream from the dam. The dam is owned by Puerto Rico Electric Power Authority. Gage-height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 96-4153,Februay 1995. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 841.29 ft (256.42 m), Sept. 22, 1998; minimun elevation, 737.92 ft (224.92 m), Aug. 8, 1997. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 826.50 ft (251.92 m), Oct. 12; minimum elevation, 797.19 ft (242.98 m), September 13, 2001. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 96-4153,Puerto Rico-1995) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 689 0 745 6,015 705 778 764 10,077 725 2,919 830 42,295 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 824.22 823.23 822.54 824.04 821.07 820.00 817.76 814.45 816.24 809.01 805.70 799.37 2 824.69 823.16 822.47 824.10 820.92 820.04 817.49 814.19 815.87 808.69 805.43 799.36 3 825.21 823.01 822.40 824.16 820.78 820.03 817.02 A 816.15 807.83 805.67 799.34 4 825.27 822.55 822.34 824.06 820.61 820.01 816.77 A 816.06 807.62 805.76 799.16 5 825.17 821.99 822.27 823.95 820.46 820.02 816.72 A 815.84 806.74 805.82 798.76 6 825.20 822.12 822.19 823.88 820.35 819.62 816.71 A 815.44 806.34 805.50 798.87 7 825.84 821.29 822.09 823.94 820.42 819.61 816.41 A 815.04 806.13 805.38 798.76 8 825.68 820.62 822.13 823.95 820.46 819.60 816.46 A 814.66 805.86 804.99 799.50 9 825.49 820.70 822.24 823.69 820.46 819.35 816.34 820.46 814.26 805.47 804.57 799.99 10 825.93 820.73 822.33 823.51 820.50 819.36 816.05 820.88 813.91 805.25 804.17 799.59 11 826.35 820.63 822.43 823.42 820.33 819.37 815.57 821.01 813.48 804.95 803.88 799.44 12 825.47 821.32 822.46 823.15 820.27 818.95 815.30 821.33 813.04 805.05 803.60 799.41 13 824.90 821.50 822.57 822.73 820.29 818.94 815.34 821.54 813.09 805.11 803.29 798.65 14 824.32 A 822.67 821.99 820.31 818.93 815.15 821.50 812.67 806.95 803.15 798.53 15 823.77 A 822.85 822.13 820.25 818.78 815.04 821.45 812.24 807.78 802.84 798.54 16 824.02 A 822.98 822.08 820.28 818.75 814.89 821.42 811.85 807.91 802.19 798.63 17 823.85 A 823.11 822.01 820.25 818.74 814.63 821.19 811.58 807.96 801.48 799.17 18 823.35 A 823.20 821.91 820.12 818.72 814.34 821.09 811.74 807.77 801.30 799.56 19 823.22 A 823.30 821.82 819.98 818.55 813.95 820.79 811.37 807.72 801.24 799.74 20 824.10 A 823.39 821.65 819.99 818.54 813.61 820.41 810.93 807.41 800.74 800.52 21 824.56 823.62 823.48 821.50 820.03 818.21 813.66 820.16 810.51 807.32 800.55 801.85 22 825.41 823.63 823.56 821.26 820.05 818.31 813.74 819.98 810.26 807.62 800.23 802.30 23 825.34 823.46 823.65 821.33 820.13 818.47 813.77 819.56 810.02 807.84 801.09 802.97 24 825.61 823.31 823.74 821.06 820.12 819.17 813.87 819.16 809.85 807.77 801.30 803.64 25 825.58 823.14 823.80 820.99 820.20 819.44 813.82 818.72 809.54 807.66 800.99 803.74 26 825.29 822.83 823.94 820.99 820.25 819.06 814.02 818.38 809.21 807.37 801.06 803.72 27 825.07 822.77 824.06 821.05 820.11 818.68 814.47 818.15 808.84 807.15 800.64 803.33 28 824.68 822.62 824.14 820.94 820.12 818.62 814.45 817.78 808.85 806.74 799.94 802.71 29 824.24 822.57 824.04 821.16 --- 818.36 814.44 817.42 808.78 806.57 799.43 801.87 30 823.85 822.55 823.97 821.14 --- 817.99 814.53 817.00 808.86 806.34 799.40 801.64 31 823.30 --- 823.98 821.17 --- 817.88 --- 816.66 --- 805.99 799.39 --- MAX 826.35 --- 824.14 824.16 821.07 820.04 817.76 --- 816.24 809.01 805.82 803.74 MIN 823.22 --- 822.09 820.94 819.98 817.88 813.61 --- 808.78 804.95 799.39 798.53 A No gage-height record 107 RIO GRANDE DE ARECIBO BASIN 50026140 LAGO CAONILLAS AT DAMSITE NEAR UTUADO, PR--Continued O N D 2000 J F M A M J J A S 2001 795 800 805 810 815 820 825 830 ELEVATION, IN FEET Gap indicates missing record 108 RIO GRANDE DE ARECIBO BASIN 50026200 RIO CAONILLAS BLW LAGO CAONILLAS TUNNEL, PR LOCATION.--Lat 18°17'57",long 66°38'36", Hydrologic Unit 21010001, on left bank at Río Caonillas Tunnel, 1.6 mi (2.6 km) downstream of Lago Caonillas Dam, 3.1 mi (5.0 km) southeast from Central Hidroelétrica of Lago Dos Bocas, 2.6 mi (4.2 km)west from Escuela Segunda Unidad de Mameyes. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 2000 to September 2001. GAGE.--Water-stage recorder. Elevation of gage 295 ft (90 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 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 --- --- --- 21 71 70 e64 e80 169 67 153 160 2 --- --- --- 21 82 29 e108 e180 152 153 157 155 3 --- --- --- 21 74 39 159 e170 77 190 192 154 4 --- --- --- 69 80 31 105 e80 136 195 118 96 5 --- --- --- 58 78 26 81 e83 154 190 66 186 6 --- --- --- 59 64 142 71 e54 166 225 164 130 7 --- --- --- 21 20 32 130 e26 174 102 107 150 8 --- --- --- 35 24 27 26 e82 149 116 159 39 9 --- --- --- 113 23 97 68 e157 147 133 162 94 10 --- --- --- 94 21 27 e141 e254 137 151 151 231 11 --- --- --- 64 73 25 e170 e277 154 163 139 137 12 --- --- --- 121 64 140 106 e29 151 158 128 136 13 --- --- e23 164 24 29 e30 e27 107 153 126 268 14 --- --- 22 157 24 29 e107 e107 157 59 111 112 15 --- --- 23 92 53 67 e61 85 152 64 159 98 16 --- --- 23 66 22 31 71 74 151 76 211 59 17 --- --- 23 58 40 29 e118 129 157 74 230 31 18 --- --- 24 67 67 29 e138 107 164 132 106 57 19 --- --- 22 64 66 73 e147 167 167 93 105 59 20 --- --- e20 81 26 26 e148 168 159 150 182 124 21 --- --- 20 79 25 124 e29 122 150 86 104 89 22 --- --- 20 104 35 e35 e81 126 149 35 144 146 23 --- --- 20 23 24 e35 e81 172 147 50 322 246 24 --- --- 20 112 57 e40 e27 167 149 110 133 121 25 --- --- 20 54 27 28 e144 172 159 101 185 136 26 --- --- 20 32 28 155 e31 148 156 161 185 163 27 --- --- 20 28 69 153 e30 154 141 151 211 216 28 --- --- 20 102 31 64 e86 176 143 170 251 265 29 --- --- 67 30 --- 114 e79 159 113 131 196 293 30 --- --- 61 82 --- 142 e26 177 142 142 219 143 31 --- --- 42 32 --- e64 --- 178 --- 152 199 --- TOTAL --- --- --- 2124 1292 1952 2663 4087 4429 3933 5075 4294 MEAN --- --- --- 68.5 46.1 63.0 88.8 132 148 127 164 143 MAX --- --- --- 164 82 155 170 277 174 225 322 293 MIN --- --- --- 21 20 25 26 26 77 35 66 31 AC-FT --- --- --- 4210 2560 3870 5280 8110 8780 7800 10070 8520 CFSM --- --- --- 1.35 .91 1.24 1.75 2.60 2.91 2.50 3.22 2.82 IN. --- --- --- 1.56 .95 1.43 1.95 2.99 3.24 2.88 3.72 3.14 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2001 - 2001, BY WATER YEAR (WY) MEAN --- --- --- 68.5 46.1 63.0 88.8 132 148 127 164 143 MAX --- --- --- 68.5 46.1 63.0 88.8 132 148 127 164 143 (WY) --- --- --- 2001 2001 2001 2001 2001 2001 2001 2001 2001 MIN --- --- --- 68.5 46.1 63.0 88.8 132 148 127 164 143 (WY) --- --- --- 2001 2001 2001 2001 2001 2001 2001 2001 2001 SUMMARY STATISTICS FOR 2001 WATER YEAR HIGHEST DAILY MEAN 322 Aug 23 LOWEST DAILY MEAN 20 Dec 20 ANNUAL SEVEN-DAY MINIMUM 20 Dec 20 10 PERCENT EXCEEDS 175 50 PERCENT EXCEEDS 104 90 PERCENT EXCEEDS 24 e Estimated 109 RIO GRANDE DE ARECIBO BASIN 50026200 RIO CAONILLAS BLW LAGO CAONILLAS TUNNEL, PR--Continued O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND Gap indicates missing record 110 RIO GRANDE DE ARECIBO BASIN 50026400 RIO YUNES AT HWY 140 NEAR FLORIDA, PR LOCATION.--Lat 18°19'27', long 66°35'13", Hydrologic Unit 21010002, on left bank, 600 ft downstream from bridge on Hwy 140, 3.07 mi (4.9 km) southwest from Florida Plaza, 2.41 mi (3.9 km) northwest from Escuela Segunda Unidad de Frontón, 1.9 mi (3.06km)northeast from Escuela Segunda Unidad de Mameyes. DRAINAGE AREA.--13.9 mi2 (36.1 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--June 2000 to current year. GAGE.--Water-stage recorder. Elevation of gage is 492 ft (150 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13 194 17 9.9 9.7 8.6 5.7 13 12 9.5 10 18 2 20 97 16 9.7 8.8 8.4 5.7 9.0 9.7 7.8 10 17 3 42 122 15 9.8 8.1 7.9 5.7 7.9 8.7 6.5 205 13 4 34 50 15 9.1 7.5 7.7 5.3 7.4 12 14 46 11 5 19 39 15 8.8 7.3 7.7 13 7.1 8.6 11 20 10 6 16 34 14 8.7 7.3 7.4 21 75 8.0 6.8 16 9.7 7 15 31 14 8.6 7.2 7.1 13 130 7.1 6.2 14 9.5 8 17 30 13 8.5 6.9 6.7 7.3 55 7.0 5.8 12 9.2 9 15 29 13 8.3 7.0 6.5 6.9 50 6.9 5.6 12 9.0 10 16 27 13 8.4 6.9 6.1 6.4 75 6.6 5.7 13 9.0 11 72 26 13 8.0 9.1 6.0 7.0 56 6.4 51 11 9.0 12 31 26 14 7.9 9.1 6.0 6.4 24 6.2 121 10 9.3 13 17 e25 15 8.0 9.2 6.2 6.4 16 6.3 48 9.9 11 14 15 24 14 8.4 7.4 6.6 8.3 18 7.0 31 9.6 8.4 15 15 24 18 8.8 8.1 6.0 5.9 15 6.3 25 9.7 42 16 31 23 19 7.9 7.9 5.9 5.9 12 6.2 12 9.5 16 17 37 22 20 7.8 8.2 5.7 5.7 11 14 9.9 14 36 18 35 21 16 7.2 7.0 5.6 5.4 11 33 16 17 25 19 218 21 e13 6.9 6.9 5.6 5.4 17 18 14 13 13 20 62 21 e12 6.7 6.7 6.6 5.5 9.8 8.5 8.9 11 66 21 28 22 12 6.8 7.4 7.2 8.5 8.8 7.2 8.1 9.4 134 22 25 22 12 6.7 23 7.2 17 8.5 6.6 8.0 9.7 148 23 86 20 11 6.9 11 9.0 25 8.7 6.4 88 26 51 24 70 19 11 6.8 12 11 14 7.6 6.8 33 12 26 25 38 18 11 6.6 15 9.6 22 7.2 7.9 15 10 17 26 27 19 14 7.0 12 6.5 72 7.0 7.0 11 15 16 27 23 18 16 11 9.8 6.6 40 28 6.7 10 17 13 28 22 17 11 23 9.3 6.8 15 27 8.0 9.6 11 10 29 20 17 11 45 --- 7.1 11 11 13 17 11 9.1 30 119 17 10 31 --- 5.9 12 9.4 12 19 11 8.4 31 75 --- 10 12 --- 5.9 --- 15 --- 12 11 --- TOTAL 1273 1075 428 330.2 255.8 217.1 388.4 757.4 280.1 646.4 615.8 783.6 MEAN 41.1 35.8 13.8 10.7 9.14 7.00 12.9 24.4 9.34 20.9 19.9 26.1 MAX 218 194 20 45 23 11 72 130 33 121 205 148 MIN 13 17 10 6.6 6.7 5.6 5.3 7.0 6.2 5.6 9.4 8.4 AC-FT 2520 2130 849 655 507 431 770 1500 556 1280 1220 1550 CFSM 2.94 2.56 .99 .76 .65 .50 .93 1.75 .67 1.49 1.42 1.87 IN. 3.38 2.86 1.14 .88 .68 .58 1.03 2.01 .74 1.72 1.64 2.08 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2001, BY WATER YEAR (WY) MEAN 41.1 35.8 13.8 10.7 9.14 7.00 12.9 24.4 9.34 14.6 15.4 25.9 MAX 41.1 35.8 13.8 10.7 9.14 7.00 12.9 24.4 9.34 20.9 19.9 26.1 (WY) 2001 2001 2001 2001 2001 2001 2001 2001 2001 2001 2001 2001 MIN 41.1 35.8 13.8 10.7 9.14 7.00 12.9 24.4 9.34 8.39 11.0 25.8 (WY) 2001 2001 2001 2001 2001 2001 2001 2001 2001 2000 2000 2000 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 2000 - 2001 ANNUAL TOTAL 7050.8 ANNUAL MEAN 19.3 19.3 HIGHEST ANNUAL MEAN 19.3 2001 LOWEST ANNUAL MEAN 19.3 2001 HIGHEST DAILY MEAN 218 Oct 19 218 Oct 19 218 Oct 19 2000 LOWEST DAILY MEAN 4.7 Aug 12 5.3 Apr 4 4.7 Aug 12 2000 ANNUAL SEVEN-DAY MINIMUM 5.2 Aug 12 5.9 Mar 29 5.2 Aug 12 2000 MAXIMUM PEAK FLOW 3740 Aug 3 3740 Aug 3 2001 MAXIMUM PEAK STAGE 11.27 Aug 3 11.27 Aug 3 2001 INSTANTANEOUS LOW FLOW 5.0 Apr 18 4.4 Aug 12 2000 ANNUAL RUNOFF (AC-FT) 13990 13990 ANNUAL RUNOFF (CFSM) 1.38 1.38 ANNUAL RUNOFF (INCHES) 18.75 18.76 10 PERCENT EXCEEDS 41 35 34 50 PERCENT EXCEEDS 15 11 10 90 PERCENT EXCEEDS 6.0 6.5 6.2 e Estimated 111 RIO GRANDE DE ARECIBO BASIN 50026400 RIO YUNES AT HWY 140 NEAR FLORIDA, PR--Continued O N D 2000 J F M A M J J A S 2001 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 112 RIO GRANDE DE ARECIBO BASIN 50026400 RIO YUNES AT HWY 140 NEAR FLORIDA, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--June 2000 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: June 2000 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 2000. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 740 mg/L November 1, 2000; Minimum daily mean, 1 mg/L several days during Water Year 2001. SEDIMENT LOADS: Maximum daily mean, 2,580 tons (2,340 tonnes) August 3, 2001; Minimum daily mean, 0.02 ton (0.02 tonne) several days during Water Year 2001. EXTREMES OBSERVED FOR WATER YEAR 2000.-- SEDIMENT CONCENTRATION: Maximum daily mean, 270 mg/L September 4, 2000; Minimum daily mean, 2 mg/L July 12, 13, 16, 2000. SEDIMENT LOADS: Maximum daily mean, 217 tons (197 tonnes) September 4, 2000; Minimum daily mean, 0.03 ton (0.03 tonne) July 12, 16, 2000. EXTREMES FOR CURRENT YEAR 2001.-- SEDIMENT CONCENTRATION: Maximum daily mean, 740 mg/L November 1, 2000; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 2,580 tons (2,340 tonnes) August 3, 2001; Minimum daily mean, 0.02 ton (0.02 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 --- --- --- --- --- --- --- --- --- 2 --- --- --- --- --- --- --- --- --- 3 --- --- --- --- --- --- --- --- --- 4 --- --- --- --- --- --- --- --- --- 5 --- --- --- --- --- --- --- --- --- 6 --- --- --- --- --- --- --- --- --- 7 --- --- --- --- --- --- --- --- --- 8 --- --- --- --- --- --- --- --- --- 9 --- --- --- --- --- --- --- --- --- 10 --- --- --- --- --- --- --- --- --- 11 --- --- --- --- --- --- --- --- --- 12 --- --- --- --- --- --- --- --- --- 13 --- --- --- --- --- --- --- --- --- 14 --- --- --- --- --- --- --- --- --- 15 --- --- --- --- --- --- --- --- --- 16 --- --- --- --- --- --- --- --- --- 17 --- --- --- --- --- --- --- --- --- 18 --- --- --- --- --- --- --- --- --- 19 --- --- --- --- --- --- --- --- --- 20 --- --- --- --- --- --- --- --- --- 21 --- --- --- --- --- --- --- --- --- 22 --- --- --- --- --- --- e8.6 e5 e.11 23 --- --- --- --- --- --- 8.1 4 .09 24 --- --- --- --- --- --- 7.7 5 .10 25 --- --- --- --- --- --- 7.7 5 .10 26 --- --- --- --- --- --- 8.3 5 .11 27 --- --- --- --- --- --- 8.1 5 .10 28 --- --- --- --- --- --- 7.5 5 .10 29 --- --- --- --- --- --- 7.1 5 .09 30 --- --- --- --- --- --- 6.9 5 .08 31 --- --- --- --- --- --- --- --- --- TOTAL --- --- --- --- --- --- 70.0 --- 0.88 113 RIO GRANDE DE ARECIBO BASIN 50026400 RIO YUNES AT HWY 140 NEAR FLORIDA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 6.9 4 .08 5.8 14 .22 27 55 16 2 7.1 4 .09 6.9 10 .20 38 51 8.8 3 7.1 4 .08 6.2 7 .11 13 8 .28 4 6.7 4 .08 9.0 7 .17 94 270 217 5 6.5 4 .07 7.5 5 .10 42 68 9.6 6 6.3 4 .07 5.7 4 .07 27 36 3.0 7 6.3 4 .07 5.5 4 .06 15 14 .56 8 7.9 6 .13 5.3 4 .06 12 7 .23 9 6.4 5 .08 5.0 4 .05 14 12 .74 10 6.5 4 .08 8.8 10 .30 27 40 7.7 11 6.2 3 .04 6.1 13 .22 19 19 1.2 12 6.4 2 .03 4.7 11 .14 11 5 .15 13 6.3 2 .04 4.9 10 .13 10 5 .14 14 6.1 3 .05 5.0 8 .11 9.7 5 .14 15 5.5 3 .04 6.0 7 .12 11 7 .24 16 5.4 2 .03 5.5 6 .09 9.6 5 .13 17 7.6 5 .13 5.2 5 .07 15 5 .20 18 8.1 7 .16 4.8 4 .05 63 129 56 19 6.7 6 .11 5.2 4 .05 35 22 2.3 20 51 129 63 5.3 3 .05 27 5 .36 21 16 20 1.1 5.0 3 .04 47 74 20 22 8.3 14 .31 8.2 5 .16 47 62 10 23 7.1 14 .27 95 212 66 34 22 2.3 24 6.7 14 .25 17 10 .60 23 6 .42 25 6.5 14 .25 13 5 .17 19 4 .21 26 6.5 13 .23 32 49 8.0 17 4 .18 27 6.0 8 .14 16 23 1.0 19 8 .45 28 5.6 4 .06 9.6 19 .49 18 6 .26 29 7.2 8 .19 8.1 18 .40 16 4 .17 30 7.2 19 .36 8.2 17 .38 14 4 .15 31 5.9 16 .26 10 16 .44 --- --- --- TOTAL 260.0 --- 67.88 340.5 --- 80.05 773.3 --- 358.91 YEAR 1443.8 507.72 e Estimated 114 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR LOCATION.--Lat 18°19'32',long 66°37'24", Hydrologic Unit 21010002, on right bank off Hwy. 146 2.2 mi(3.5 km) northwest from Escuela Segunda Unidad de Mameyes, 3.0 mi (4.8 km) southwest from Lago Dos Bocas Dam, 3.8 mi (6.0 km) northeast from Lago Caonillas Dam. DRAINAGE AREA.--33.2 mi2 (86.0 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1999 to current year. GAGE.--Water-stage recorder. Datum of gage is 311.6 ft (94.9 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 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 42 256 40 29 30 23 16 24 29 26 22 62 2 54 156 38 28 28 28 16 20 24 22 23 47 3 106 234 37 28 26 24 16 19 22 19 491 38 4 84 114 37 27 25 22 16 18 25 31 84 36 5 55 92 36 26 24 22 24 17 22 26 37 34 6 51 81 36 26 24 21 47 162 22 20 30 33 7 57 75 36 25 24 21 35 237 20 18 28 32 8 56 70 35 25 23 20 19 114 20 18 25 31 9 50 69 35 25 23 20 18 113 19 17 25 30 10 63 64 34 25 23 19 17 139 18 17 e26 30 11 142 61 35 24 27 19 17 112 18 54 e24 30 12 81 59 35 24 26 18 17 60 18 121 e23 31 13 56 58 37 24 28 18 17 47 49 72 e23 35 14 50 56 36 25 23 19 21 53 31 55 e23 30 15 58 56 45 27 25 18 17 53 19 51 e23 138 16 63 54 47 27 25 18 16 42 18 27 e23 52 17 128 51 49 24 25 17 15 35 33 23 29 105 18 92 50 41 23 23 17 14 34 118 28 32 66 19 477 49 35 23 23 17 14 44 50 28 25 45 20 183 47 34 22 22 18 14 31 25 21 24 138 21 112 48 33 22 24 20 20 28 21 20 22 458 22 112 49 32 22 57 21 34 33 20 20 22 240 23 152 46 32 22 30 24 53 29 19 148 46 96 24 140 44 31 22 30 27 50 24 19 58 30 65 25 103 42 32 e21 36 27 84 23 21 30 26 47 26 86 43 33 e21 30 19 120 23 20 25 115 46 27 76 42 47 e28 25 19 e68 34 18 23 62 39 28 73 40 32 e58 24 22 e30 45 20 21 41 32 29 68 39 31 e95 --- 21 24 25 35 32 37 29 30 210 39 30 e78 --- 18 23 23 29 36 35 28 31 150 --- 29 36 --- 17 --- 34 --- 24 35 --- TOTAL 3230 2184 1120 932 753 634 892 1695 822 1131 1511 2123 MEAN 104 72.8 36.1 30.1 26.9 20.5 29.7 54.7 27.4 36.5 48.7 70.8 MAX 477 256 49 95 57 28 120 237 118 148 491 458 MIN 42 39 29 21 22 17 14 17 18 17 22 28 AC-FT 6410 4330 2220 1850 1490 1260 1770 3360 1630 2240 3000 4210 CFSM 3.14 2.19 1.09 .91 .81 .62 .90 1.65 .83 1.10 1.47 2.13 IN. 3.62 2.45 1.25 1.04 .84 .71 1.00 1.90 .92 1.27 1.69 2.38 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2001, BY WATER YEAR (WY) MEAN 104 72.8 36.1 69.1 44.1 33.1 33.1 76.1 32.2 33.7 40.2 64.0 MAX 104 72.8 36.1 108 60.8 45.7 36.4 97.5 37.0 36.5 48.7 70.8 (WY) 2001 2001 2001 2000 2000 2000 2000 2000 2000 2001 2001 2001 MIN 104 72.8 36.1 30.1 26.9 20.5 29.7 54.7 27.4 31.0 31.7 57.3 (WY) 2001 2001 2001 2001 2001 2001 2001 2001 2001 2000 2000 2000 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 2000 - 2001 ANNUAL TOTAL 21953 17027 ANNUAL MEAN 60.0 46.6 46.6 HIGHEST ANNUAL MEAN 46.6 2001 LOWEST ANNUAL MEAN 46.6 2001 HIGHEST DAILY MEAN 477 Oct 19 491 Aug 3 491 Aug 3 2001 LOWEST DAILY MEAN 18 Aug 18 14 Apr 18 14 Apr 18 2001 ANNUAL SEVEN-DAY MINIMUM 19 Aug 15 16 Apr 15 16 Apr 15 2001 MAXIMUM PEAK FLOW 5700 Oct 19 5700 Oct 19 2000 MAXIMUM PEAK STAGE 12.89 Oct 19 12.89 Oct 19 2000 INSTANTANEOUS LOW FLOW 13 Apr 18 13 Apr 18 2001 ANNUAL RUNOFF (AC-FT) 43540 33770 33800 ANNUAL RUNOFF (CFSM) 1.81 1.41 1.41 ANNUAL RUNOFF (INCHES) 24.60 19.08 19.09 10 PERCENT EXCEEDS 110 92 112 50 PERCENT EXCEEDS 46 30 36 90 PERCENT EXCEEDS 26 19 20 e Estimated 115 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR--Continued O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 116 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--November 2000 to September 2001. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: December 1999 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 1999. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,650 mg/L August 3, 2001; Minimum daily mean, 1 mg/L several days during Water Year 2001. SEDIMENT LOADS: Maximum daily mean, 8,810 tons (7,992 tonnes) October 19, 2000; Minimum daily mean, 0.08 ton (0.07 tonne) February 6, 7, 2001. EXTREMES OBSERVED FOR WATER YEAR 2000.-- SEDIMENT CONCENTRATION: Maximum daily mean, 820 mg/L May 3, 2000; Minimum daily mean, 3 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 2,580 tons (2,340 tonnes) May 3, 2000; Minimum daily mean, 0.24 ton (0.24 tonne) July 16, 2000. EXTREMES FOR CURRENT YEAR 2001.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,650 mg/L August 3, 2001; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 8,810 tons (7,992 tonnes) October 19, 2000; Minimum daily mean, 0.08 ton (0.07 tonne) February 6, 7, 2001. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) NOV 02... 1400 110 180 7.2 25.0 31 7.4 -- <10 3100 500 61 17.1 MAY 17... 1105 38 209 7.5 25.1 2.4 8.2 100 <10 240 220 83 24.0 SEP 10... 1040 26 198 7.4 26.5 -- 8.3 104 <10 E100 E130 80 22.0 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) NOV 02... 4.54 7.6 .4 2.18 -- <1.0 6.0 7.9 E.1 26.4 109 32.3 27 MAY 17... 5.58 9.4 .5 1.62 82 <1.0 5.5 10.6 E.1 26.8 133 13.5 <10 SEP 10... 6.05 9.9 .5 2.09 79 -- 4.7 10.4 <.2 26.2 128 9.08 <10 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) NOV 02... 1.29 .01 1.3 .04 .35 .39 1.7 7.5 .060 <2 45.7 E17 <.11 MAY 17... -- <.01 .6 <.01 -- .23 .85 3.8 .030 <2 39.9 E15 <.10 SEP 10... -- <.01 .6 .01 -- <.20 -- -- <.020 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 02... 1 <20.0 730 <1 35 <.14 <2.6 <.43 <31 <.01 <16 <.02 MAY 17... <1 <20.0 60 <1 9 <.01 <3.0 <.40 <31 <.01 E10 .03 SEP 10... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 117 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR--Continued WATER-QUALITY RECORDS SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 --- --- --- --- --- --- --- --- --- 2 --- --- --- --- --- --- --- --- --- 3 --- --- --- --- --- --- --- --- --- 4 --- --- --- --- --- --- --- --- --- 5 --- --- --- --- --- --- --- --- --- 6 --- --- --- --- --- --- --- --- --- 7 --- --- --- --- --- --- --- --- --- 8 --- --- --- --- --- --- --- --- --- 9 --- --- --- --- --- --- --- --- --- 10 --- --- --- --- --- --- --- --- --- 11 --- --- --- --- --- --- --- --- --- 12 --- --- --- --- --- --- --- --- --- 13 --- --- --- --- --- --- --- --- --- 14 --- --- --- --- --- --- --- --- --- 15 --- --- --- --- --- --- --- --- --- 16 --- --- --- --- --- --- --- --- --- 17 --- --- --- --- --- --- 150 133 54 18 --- --- --- --- --- --- 139 119 45 19 --- --- --- --- --- --- 139 120 45 20 --- --- --- --- --- --- 140 120 45 21 --- --- --- --- --- --- 142 124 48 22 --- --- --- --- --- --- 164 157 70 23 --- --- --- --- --- --- 138 117 44 24 --- --- --- --- --- --- 135 115 42 25 --- --- --- --- --- --- 134 112 40 26 --- --- --- --- --- --- 129 108 38 27 --- --- --- --- --- --- 117 91 29 28 --- --- --- --- --- --- 133 116 46 29 --- --- --- --- --- --- 171 165 79 30 --- --- --- --- --- --- 131 107 38 31 --- --- --- --- --- --- 121 91 30 TOTAL --- --- --- --- --- --- 2083 --- 693 118 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 114 83 26 68 37 6.7 52 6 .89 2 113 75 23 66 35 6.3 51 6 .86 3 225 365 415 66 34 6.0 50 6 .82 4 180 181 89 65 32 5.6 49 6 .79 5 145 130 51 63 31 5.2 49 6 .76 6 149 134 61 61 29 4.8 48 6 .74 7 145 131 53 61 28 4.5 47 6 .71 8 130 108 39 60 26 4.2 47 5 .68 9 119 107 34 58 25 3.9 46 5 .66 10 111 83 25 57 23 3.6 45 5 .63 11 107 78 23 56 22 3.2 44 5 .64 12 103 73 20 55 20 3.0 44 9 1.1 13 110 81 24 54 19 2.7 44 13 1.6 14 106 77 22 54 17 2.5 43 12 1.4 15 109 90 31 52 16 2.2 42 10 1.1 16 144 143 66 51 14 2.0 42 7 .84 17 104 85 24 51 13 1.7 45 7 .80 18 97 81 21 52 11 1.6 41 6 .69 19 93 78 20 52 10 1.3 40 6 .62 20 90 75 18 50 8 1.1 39 5 .55 21 88 71 17 49 6 .86 40 5 .52 22 85 68 16 61 22 4.3 44 4 .52 23 83 64 14 106 93 65 38 4 .41 24 80 61 13 78 31 8.5 44 4 .41 25 78 58 12 83 44 11 39 3 .32 26 77 54 11 61 7 1.1 48 15 3.2 27 75 51 10 65 7 1.2 52 23 4.0 28 73 47 9.3 55 7 .99 38 7 .70 29 78 44 9.2 53 6 .94 48 22 3.1 30 73 41 8.0 --- --- --- 65 39 13 31 69 38 7.1 --- --- --- 52 17 2.9 TOTAL 3353 --- 1211.6 1763 --- 165.99 1416 --- 45.96 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 39 5 .48 32 12 1.1 42 3 .34 2 38 7 .74 43 20 2.6 42 3 .34 3 42 10 1.2 298 820 2580 41 3 .33 4 38 13 1.3 201 346 406 40 3 .32 5 37 16 1.6 144 197 117 38 3 .31 6 35 19 1.8 64 46 8.0 38 3 .31 7 35 22 2.0 51 34 4.7 37 3 .30 8 34 25 2.3 205 436 656 38 3 .31 9 33 27 2.4 261 474 532 41 3 .33 10 32 28 2.4 143 142 61 38 3 .30 11 33 26 2.3 e262 e489 e664 35 3 .28 12 34 24 2.2 e131 e129 e47 e38 e3 e.31 13 32 22 1.9 e93 e43 e12 e58 e28 e6.5 14 31 21 1.7 e76 e7 e1.4 44 9 1.2 15 30 19 1.5 e67 e6 e1.2 36 3 .29 16 30 17 1.4 e62 e6 e1.0 40 8 1.1 17 31 15 1.3 e88 e61 e25 41 18 2.1 18 31 14 1.1 e79 e17 e4.5 34 13 1.2 19 30 12 .96 e63 e7 e1.1 33 12 1.1 20 74 47 18 e57 e7 e1.0 38 17 2.2 21 70 45 10 e53 e6 e.92 42 19 2.3 22 59 34 5.8 e52 e6 e.87 33 14 1.3 23 36 15 1.5 88 104 50 31 14 1.1 24 33 14 1.2 66 9 1.7 30 13 1.1 25 31 13 1.1 60 4 .67 30 12 1.0 26 30 13 1.0 52 4 .53 35 12 1.1 27 29 12 .94 48 4 .48 32 11 .96 28 28 12 .88 48 4 .45 29 11 .84 29 29 11 .85 46 3 .42 29 10 .77 30 29 10 .81 46 3 .39 28 9 .72 31 --- --- --- 43 3 .35 --- --- --- TOTAL 1093 --- 72.66 3022 --- 5183.38 1111 --- 30.66 119 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 28 9 .66 23 6 .39 44 37 12 2 29 8 .64 26 6 .43 72 41 12 3 28 8 .58 24 6 .38 37 7 .67 4 26 7 .50 e29 e6 e.46 94 209 144 5 26 6 .44 e28 e6 e.44 111 120 89 6 25 6 .39 22 6 .33 71 38 8.8 7 77 100 70 21 5 .31 47 8 1.0 8 40 17 2.2 20 5 .29 45 7 .85 9 28 6 .48 19 5 .27 69 40 13 10 26 7 .51 35 17 2.3 72 40 13 11 26 6 .42 23 7 .47 57 26 4.5 12 25 4 .27 19 5 .27 41 6 .67 13 25 4 .27 19 5 .28 36 6 .55 14 25 4 .27 19 6 .29 34 6 .59 15 23 4 .25 22 6 .35 35 8 .75 16 22 4 .24 21 6 .35 33 9 .82 17 e23 e6 e.52 19 6 .33 42 11 1.2 18 e29 e9 e.75 18 7 .33 115 108 65 19 24 6 .39 19 7 .36 74 21 4.6 20 109 138 114 19 7 .38 56 6 .91 21 49 27 4.9 18 8 .37 64 33 8.8 22 29 8 .61 24 12 1.0 67 22 4.7 23 26 8 .55 170 193 105 61 15 2.6 24 e25 e8 e.51 48 22 3.2 48 13 1.7 25 e24 e7 e.49 40 6 .64 68 60 22 26 24 7 .47 78 71 27 50 29 4.1 27 23 7 .44 43 16 2.1 49 23 3.1 28 22 7 .42 32 6 .50 48 58 8.0 29 25 7 .46 28 6 .43 41 74 8.4 30 26 7 .46 27 6 .39 37 56 5.6 31 23 6 .40 30 5 .42 --- --- --- TOTAL 960 --- 203.49 983 --- 150.06 1718 --- 442.91 YEAR 17502 8199.71 e Estimated 120 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 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 42 2 .22 256 836 1260 40 3 .32 2 54 20 3.6 156 208 98 38 3 .31 3 106 121 67 234 300 223 37 3 .30 4 84 60 16 114 117 37 37 3 .30 5 55 12 1.8 92 58 15 36 3 .32 6 51 6 .88 81 8 1.8 36 4 .34 7 57 22 4.5 75 3 .60 36 4 .37 8 56 22 3.4 70 3 .57 35 4 .38 9 50 14 1.9 69 3 .56 35 4 .39 10 63 31 7.6 64 3 .52 34 4 .41 11 142 296 283 61 3 .49 35 5 .43 12 81 56 14 59 3 .48 35 5 .46 13 56 19 2.9 58 3 .47 37 4 .43 14 50 14 1.8 56 3 .45 36 3 .29 15 58 29 5.3 56 3 .47 45 15 2.0 16 63 39 8.1 54 4 .58 47 20 2.9 17 128 508 481 51 5 .69 49 22 2.9 18 92 124 31 50 6 .80 41 13 1.5 19 477 1560 8810 49 6 .82 35 8 .75 20 183 141 87 47 6 .83 34 3 .32 21 112 25 7.6 48 7 .88 33 3 .24 22 112 73 32 49 7 .94 32 2 .20 23 152 196 120 46 8 1.0 32 2 .18 24 140 126 52 44 9 1.1 31 2 .20 25 103 55 15 42 10 1.1 32 3 .22 26 86 40 9.3 43 7 .81 33 4 .47 27 76 20 4.1 42 4 .48 47 19 3.0 28 73 19 3.7 40 4 .44 32 4 .35 29 68 18 3.4 39 4 .42 31 4 .33 30 210 1130 1390 39 3 .33 30 6 .45 31 150 168 84 --- --- --- 29 7 .55 TOTAL 3230 --- 11552.10 2184 --- 1650.63 1120 --- 21.61 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 29 8 .65 30 3 .23 23 3 .19 2 28 10 .75 28 2 .14 28 8 .76 3 28 10 .78 26 2 .12 24 4 .27 4 27 7 .53 25 2 .10 22 3 .16 5 26 4 .28 24 1 .09 22 2 .14 6 26 1 .09 24 1 .08 21 2 .12 7 25 1 .09 24 1 .08 21 2 .11 8 25 2 .10 23 4 .27 20 2 .11 9 25 2 .12 23 8 .51 20 3 .17 10 25 5 .36 23 12 .72 19 4 .23 11 24 7 .45 27 9 .67 19 6 .30 12 24 5 .31 26 5 .35 18 7 .36 13 24 3 .17 28 8 .54 18 8 .42 14 25 2 .13 23 7 .42 19 7 .37 15 27 5 .38 25 6 .41 18 5 .24 16 27 5 .37 25 7 .49 18 3 .13 17 24 3 .21 25 9 .57 17 3 .13 18 23 4 .22 23 8 .54 17 4 .17 19 23 4 .23 23 8 .48 17 5 .22 20 22 4 .23 22 7 .42 18 6 .28 21 22 3 .18 24 8 .55 20 6 .32 22 22 2 .13 57 32 5.8 21 6 .35 23 22 3 .19 30 6 .51 24 6 .38 24 22 4 .27 30 5 .42 27 12 .89 25 e21 e6 e.33 36 5 .52 27 16 1.2 26 e21 e6 e.31 30 6 .47 19 15 .77 27 e28 e5 e.39 25 6 .38 19 13 .69 28 e58 e34 e6.3 24 4 .29 22 14 .82 29 e95 e95 e44 --- --- --- 21 15 .86 30 e78 e44 e12 --- --- --- 18 12 .59 31 36 6 .61 --- --- --- 17 7 .34 TOTAL 932 --- 71.16 753 --- 16.17 634 --- 12.09 121 RIO GRANDE DE ARECIBO BASI 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 16 7 .29 24 8 .52 29 14 1.1 2 16 6 .28 20 8 .44 24 11 .73 3 16 6 .26 19 8 .40 22 9 .56 4 16 6 .26 18 8 .39 25 8 .51 5 24 7 .53 17 8 .37 22 7 .40 6 47 22 4.9 162 154 377 22 6 .37 7 35 19 2.1 237 327 462 20 6 .32 8 19 10 .53 114 140 111 20 6 .33 9 18 11 .56 113 81 34 19 7 .34 10 17 13 .58 139 136 90 18 7 .35 11 17 13 .63 112 105 35 18 8 .36 12 17 14 .64 60 17 3.0 18 8 .37 13 17 14 .64 47 6 .77 49 97 41 14 21 13 .71 53 21 4.3 31 173 18 15 17 11 .50 53 26 4.5 19 12 .60 16 16 10 .42 42 15 1.7 18 10 .45 17 15 9 .35 35 13 1.2 33 18 2.0 18 14 7 .29 34 12 1.1 118 250 283 19 14 7 .26 44 17 2.2 50 35 5.8 20 14 6 .24 31 10 .81 25 21 1.4 21 20 6 .33 28 9 .70 21 16 .94 22 34 16 2.4 33 14 1.5 20 12 .64 23 53 30 4.8 29 15 1.2 19 10 .51 24 50 41 7.5 24 9 .59 19 8 .44 25 84 119 73 23 8 .48 21 7 .41 26 120 167 85 23 6 .39 20 6 .31 27 e68 e42 e9.7 34 16 2.6 18 4 .21 28 e30 e13 e1.1 45 23 3.4 20 4 .22 29 24 11 .71 25 6 .44 35 13 1.8 30 23 8 .53 23 6 .40 29 16 1.3 31 --- --- --- 34 12 1.4 --- --- --- TOTAL 892 --- 200.04 1695 --- 1143.80 822 --- 364.77 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 26 9 .65 22 2 .12 62 47 14 2 22 6 .35 23 2 .13 47 16 2.0 3 19 4 .22 491 1650 8400 38 11 1.1 4 31 12 1.4 84 105 37 36 10 .98 5 26 9 .65 37 20 2.0 34 9 .78 6 20 5 .25 30 12 .97 33 7 .63 7 18 4 .21 28 6 .47 32 6 .47 8 18 5 .22 25 4 .25 31 5 .39 9 17 5 .24 25 3 .23 30 4 .34 10 17 6 .25 e26 e3 e.23 30 4 .29 11 54 61 25 e24 e3 e.23 30 3 .25 12 121 163 126 e23 e3 e.22 31 4 .39 13 72 62 18 e23 e3 e.22 35 11 1.1 14 55 42 13 e23 e3 e.22 30 4 .34 15 51 33 6.4 e23 e3 e.22 138 733 765 16 27 7 .51 e23 e3 e.22 52 62 9.3 17 23 4 .25 29 9 1.0 105 165 117 18 28 8 .70 32 12 1.1 66 117 21 19 28 11 .86 25 5 .31 45 97 12 20 21 7 .40 24 4 .26 138 292 322 21 20 7 .38 22 4 .21 458 917 3570 22 20 7 .37 22 3 .19 240 364 614 23 148 276 298 46 23 3.5 96 128 35 24 58 71 12 30 15 1.4 65 55 10 25 30 40 3.3 26 11 .77 47 33 4.4 26 25 12 .82 115 368 308 46 7 .84 27 23 4 .28 62 32 6.8 39 5 .49 28 21 4 .22 41 6 .68 32 4 .37 29 32 11 1.2 37 6 .58 29 4 .29 30 36 16 1.8 35 6 .53 28 3 .25 31 24 4 .27 35 5 .50 --- --- --- TOTAL 1131 --- 514.20 1511 --- 8768.56 2123 --- 5505.00 YEAR 17027 29820.13 e Estimated 122 RIO GRANDE DE ARECIBO BASIN 50027100 LAGO DOS BOCAS AT DAMSITE NEAR UTUADO, PR LOCATION.--Lat 1820'16",long 6640'05", Hydrologic Unit 21010001, on upstream side of road 146 over damsite, close to the center of dam, 10 mi (16 km) southeast of the city of Arecibo, 4.10 mi (6.60 km) north of Lago Caonillas Dam, 5.30 mi (8.53 km) northeast of Utuado Plaza, and 3.80 mi (6.11 km) southeast of Escuela Antonio Sánchez de Padilla. DRAINAGE AREA.--169.45 mi2 (438.87 km2). ELEVATION RECORDS PERIOD OF RECORD.--March 1999 to current year. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Dos Bocas was completed in 1942. The dam is a concrete gravity structure with a total length of 1,317 ft (401.4 m), a maximum height of 188 ft (57.3 m), and a maximum base width of 158 ft (48.2 m). No-overflow sections on each abutment have a total lenght of 957 ft (292 m). The dam and the powerplant comprise the Dos Bocas Hydroelectric Project, and provides 32,000 acre-feet (39.456 km3). A three-unit powerplant is located on the right bank of the slitting basin. The dam is owned by Puerto Rico Electric Power Authority. The capacity of Lago Dos Bocas was computed to be 714.40 million ft3(20.23 million m3) for June 1997. The Puerto Rico Aqueduct and Sewer Authority (PRASA) plans to withdraw water from the Rio Grande de Arecibo, south of the town of Arecibo, to supply potable water for areas between Arecibo and San Juan town. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 298.55 ft (90.99 m),Nov. 19,1999; minimum elevation, 283.88 ft (86.526 m), Aug. 21, 2000. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 297.58 ft (90.702 m), May 7, 2001;minimum elevation, 284.58 ft (86.740 m), Mar 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 216 0 275 9,283 236 1,403 288 13,684 256 4,491 295 16,400 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 288.53 292.27 293.22 288.05 288.94 288.72 286.23 A 291.94 289.89 290.46 292.63 2 290.66 292.46 293.12 288.23 289.30 289.28 286.90 291.00 291.10 287.91 292.43 292.72 3 291.80 292.60 293.00 288.76 289.59 289.48 285.63 A 291.16 287.25 293.20 292.20 4 A 291.83 292.68 288.05 289.35 288.95 286.36 289.75 289.40 288.57 291.94 292.59 5 291.26 291.78 292.59 287.63 289.20 289.27 287.21 288.40 289.55 288.60 292.00 291.98 6 291.45 291.07 292.46 287.17 288.98 287.91 288.35 296.52 288.68 289.96 289.73 292.27 7 292.95 291.37 292.35 287.64 289.41 288.07 288.50 293.62 289.44 290.61 290.09 292.65 8 A 290.13 292.10 287.73 288.66 288.36 288.94 A 290.34 290.75 291.19 293.43 9 A 290.37 291.72 286.62 289.02 288.28 289.40 290.72 290.39 291.52 291.48 292.49 10 292.15 291.25 291.27 287.46 289.35 288.54 290.09 292.63 290.90 291.60 292.21 291.51 11 292.38 292.60 290.82 286.08 288.76 288.79 288.91 291.41 291.30 292.30 291.61 291.24 12 291.01 292.00 290.36 287.07 288.93 287.77 289.55 A 291.36 293.05 290.86 291.00 13 291.89 291.78 289.34 286.01 288.78 288.05 289.79 291.02 290.34 291.57 289.11 291.67 14 291.96 292.57 288.88 287.21 289.09 288.13 290.30 290.92 289.91 290.79 288.27 291.24 15 293.51 292.55 288.43 287.04 289.02 287.39 289.90 A 289.13 288.70 289.48 290.84 16 294.61 291.74 289.00 287.84 289.33 287.31 289.64 290.60 289.24 288.95 289.10 290.78 17 294.12 290.97 289.78 287.45 288.02 287.57 290.17 A 290.57 288.41 290.13 290.88 18 291.97 290.80 289.48 287.06 288.59 287.81 A A 291.97 289.49 290.26 291.22 19 296.64 290.55 289.60 287.01 288.28 287.12 A 289.74 291.55 289.99 290.41 290.08 20 294.87 290.35 289.70 287.75 288.58 287.43 A 290.89 290.03 290.98 290.34 290.91 21 293.78 291.24 290.06 288.39 288.42 285.25 A A 290.17 290.18 291.17 294.51 22 294.30 292.51 290.48 287.75 289.03 285.43 A A 290.06 290.20 290.47 292.90 23 293.98 292.63 291.03 288.19 289.40 285.69 A A 290.15 290.71 291.20 292.23 24 293.28 292.97 291.55 287.08 289.29 286.36 A A 290.38 290.58 292.42 293.74 25 291.58 293.10 292.06 286.78 289.68 286.86 292.29 290.39 290.15 289.57 292.44 293.63 26 288.60 292.18 289.80 286.67 289.97 285.62 293.36 290.63 289.32 290.12 293.98 293.44 27 291.76 292.05 289.38 287.19 289.21 286.18 A A 289.39 291.86 292.97 293.03 28 292.44 292.24 288.80 287.84 289.40 286.92 293.67 290.70 290.25 292.32 291.47 292.06 29 293.74 292.95 288.37 288.81 --- 284.94 293.37 288.79 291.22 292.31 289.96 290.60 30 293.70 293.33 288.45 289.49 --- 285.35 293.62 289.39 291.71 289.70 290.69 290.44 31 292.18 --- 288.35 289.18 --- 285.82 --- 290.84 --- 289.61 291.22 --- MAX --- 293.33 293.22 289.49 289.97 289.48 --- --- 291.97 293.05 293.98 294.51 MIN --- 290.13 288.35 286.01 288.02 284.94 --- --- 288.68 287.25 288.27 290.08 A No gage-height record 123 RIO GRANDE DE ARECIBO BASIN 50027100 LAGO DOS BOCAS AT DAMSITE NEAR UTUADO, PR--Continued O N D 2000 J F M A M J J A S 2001 284 286 288 290 292 294 296 298 ELEVATION, IN FEET Gap indicates missing record 124 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR LOCATION.--Lat 18°20'50', long 66°40'02", Hydrologic Unit 21010001, at pedestrian bridge, 0.7 mi (1.1 km) downstream from Lago Dos Bocas and 6.6 mi, (10.6 km), west of Florida plaza. DRAINAGE AREA.--170 mi2 (440 km2) does not include 6.0 mi2 (15.6 km2) above Lago Garzas. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--May 2000 to current year. GAGE.--Water-stage recorder. Elevation of gage is 102 ft (40 m), from topographic map. REMARKS.--Records poor. Regulation at all stages by Puerto Rico Electric Power Authority reservoir upstream from gage. Gage-height satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 --- --- --- --- --- --- --- --- 633 260 264 e884 2 --- --- --- --- --- --- --- --- 369 27 315 e975 3 --- --- --- --- --- --- --- --- 604 21 317 e811 4 --- --- --- --- --- --- --- --- 577 35 e677 e908 5 --- --- --- --- --- --- --- --- 32 192 e816 e642 6 --- --- --- --- --- --- --- --- 283 21 38 e659 7 --- --- --- --- --- --- --- --- 282 44 152 e954 8 --- --- --- --- --- --- --- --- 294 139 e227 e303 9 --- --- --- --- --- --- --- --- 297 248 e170 e721 10 --- --- --- --- --- --- --- --- e258 261 e33 e962 11 --- --- --- --- --- --- --- --- e274 767 e23 e882 12 --- --- --- --- --- --- --- --- e32 124 e87 e37 13 --- --- --- --- --- --- --- --- e280 e120 e75 e409 14 --- --- --- --- --- --- --- --- 78 43 e49 e302 15 --- --- --- --- --- --- --- --- 928 215 e337 e638 16 --- --- --- --- --- --- --- --- 535 463 e246 e1160 17 --- --- --- --- --- --- --- e1160 1280 e55 e364 e929 18 --- --- --- --- --- --- --- e1160 333 e60 e44 e664 19 --- --- --- --- --- --- --- 1100 463 153 e24 e971 20 --- --- --- --- --- --- --- 1110 283 466 e49 e1240 21 --- --- --- --- --- --- --- 30 354 479 e680 e1450 22 --- --- --- --- --- --- --- 26 543 98 e114 e2040 23 --- --- --- --- --- --- --- 398 145 611 e2120 e1700 24 --- --- --- --- --- --- --- 421 251 e223 e2040 e1910 25 --- --- --- --- --- --- --- e421 244 294 e1200 e1480 26 --- --- --- --- --- --- --- e283 210 223 e925 e1180 27 --- --- --- --- --- --- --- 517 25 312 e1310 e1190 28 --- --- --- --- --- --- --- 668 392 44 e889 e1560 29 --- --- --- --- --- --- --- 701 205 e274 e478 e1770 30 --- --- --- --- --- --- --- 589 405 e264 e465 e535 31 --- --- --- --- --- --- --- 812 --- 274 e701 --- TOTAL --- --- --- --- --- --- --- --- 10889 6810 15229 29866 MEAN --- --- --- --- --- --- --- --- 363 220 491 996 MAX --- --- --- --- --- --- --- --- 1280 767 2120 2040 MIN --- --- --- --- --- --- --- --- 25 21 23 37 AC-FT --- --- --- --- --- --- --- --- 21600 13510 30210 59240 CFSM --- --- --- --- --- --- --- --- 2.14 1.29 2.89 5.86 IN. --- --- --- --- --- --- --- --- 2.38 1.49 3.33 6.54 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2000, BY WATER YEAR (WY) MEAN --- --- --- --- --- --- --- --- 363 220 491 996 MAX --- --- --- --- --- --- --- --- 363 220 491 996 (WY) --- --- --- --- --- --- --- --- 2000 2000 2000 2000 MIN --- --- --- --- --- --- --- --- 363 220 491 996 (WY) --- --- --- --- --- --- --- --- 2000 2000 2000 2000 SUMMARY STATISTICS FOR 2000 WATER YEAR HIGHEST DAILY MEAN 2120 Aug 23 LOWEST DAILY MEAN 21 Jul 3 ANNUAL SEVEN-DAY MINIMUM 68 Jul 2 10 PERCENT EXCEEDS 1190 50 PERCENT EXCEEDS 354 90 PERCENT EXCEEDS 38 e Estimated 125 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR--Continued O N D 1999 J F M A M J J A S 2000 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND Gap indicates missing record 126 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR--Continued DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e878 1420 427 e250 e303 e416 e26 386 30 862 227 462 2 e226 1070 390 e135 e143 e32 e26 882 588 961 44 602 3 e558 1160 e348 e28 e151 e109 e637 435 230 672 1120 711 4 e898 1170 e437 e412 e289 e300 e29 279 873 126 995 293 5 e958 925 368 337 e270 e35 e29 541 363 520 300 696 6 e644 1060 372 350 e281 e680 e42 516 645 33 1140 537 7 e958 577 365 32 e45 e104 e403 3230 140 49 248 573 8 e694 e878 361 158 e383 e30 e30 1440 30 204 34 287 9 e1370 e541 354 597 e29 e245 e55 1040 279 39 349 841 10 e1460 e228 e375 32 e29 e29 e26 1090 125 544 216 969 11 e1060 89 e375 591 e378 e29 e657 1500 187 432 598 553 12 e1170 672 e368 43 e178 e572 e29 784 270 455 608 672 13 e636 e697 e596 663 e232 e30 e30 30 819 1030 843 698 14 e727 219 e368 33 e43 e96 26 690 529 737 549 569 15 e610 e453 e395 314 e225 e368 264 469 567 987 206 665 16 e697 e525 e163 31 e36 e151 262 427 307 207 604 340 17 e1440 e558 e29 350 e573 e28 30 569 288 411 198 360 18 e1820 371 e330 336 e38 e28 462 681 435 30 269 277 19 e2260 412 e254 e250 e289 e357 374 176 646 150 283 605 20 2380 357 e389 e31 e39 e29 240 28 854 30 529 304 21 1550 226 e136 48 e233 e731 269 145 306 488 33 437 22 1220 34 e86 446 e123 e133 37 673 367 253 560 1560 23 1940 447 e27 29 e40 e97 27 307 360 423 812 1060 24 1630 e373 e28 597 e268 e28 34 541 392 455 87 371 25 1700 401 e28 274 e54 e27 270 288 464 619 494 582 26 1940 807 e991 e210 e68 e688 209 265 648 235 304 682 27 37 446 e443 e30 e438 e170 108 541 317 34 936 827 28 887 e341 e437 e213 e97 e28 328 300 222 259 1050 1010 29 677 167 e376 121 --- e776 289 902 217 363 977 1100 30 1360 275 e237 e211 --- e112 75 205 301 1310 426 508 31 1610 --- e249 e289 --- e26 --- 33 --- 391 545 --- TOTAL 35995 16899 10102 7441 5275 6484 5323 19393 11799 13309 15584 19151 MEAN 1161 563 326 240 188 209 177 626 393 429 503 638 MAX 2380 1420 991 663 573 776 657 3230 873 1310 1140 1560 MIN 37 34 27 28 29 26 26 28 30 30 33 277 AC-FT 71400 33520 20040 14760 10460 12860 10560 38470 23400 26400 30910 37990 CFSM 6.83 3.31 1.92 1.41 1.11 1.23 1.04 3.68 2.31 2.53 2.96 3.76 IN. 7.88 3.70 2.21 1.63 1.15 1.42 1.16 4.24 2.58 2.91 3.41 4.19 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2001, BY WATER YEAR (WY) MEAN 1161 563 326 240 188 209 177 626 378 324 497 817 MAX 1161 563 326 240 188 209 177 626 393 429 503 996 (WY) 2001 2001 2001 2001 2001 2001 2001 2001 2001 2001 2001 2000 MIN 1161 563 326 240 188 209 177 626 363 220 491 638 (WY) 2001 2001 2001 2001 2001 2001 2001 2001 2000 2000 2000 2001 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 2000 - 2001 ANNUAL TOTAL 166755 ANNUAL MEAN 457 457 HIGHEST ANNUAL MEAN 457 2001 LOWEST ANNUAL MEAN 457 2001 HIGHEST DAILY MEAN 2380 Oct 20 3230 May 7 3230 May 7 2001 LOWEST DAILY MEAN 21 Jul 3 26 Mar 31 21 Jul 3 2000 ANNUAL SEVEN-DAY MINIMUM 68 Jul 2 88 Apr 4 68 Jul 2 2000 MAXIMUM PEAK FLOW 7390 May 7 7390 May 7 2001 MAXIMUM PEAK STAGE 14.62 May 7 14.62 May 7 2001 ANNUAL RUNOFF (AC-FT) 330800 331000 ANNUAL RUNOFF (CFSM) 2.69 2.69 ANNUAL RUNOFF (INCHES) 36.49 36.51 10 PERCENT EXCEEDS 1360 993 1060 50 PERCENT EXCEEDS 412 361 360 90 PERCENT EXCEEDS 44 30 32 e Estimated 127 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR--Continued O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 128 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°20'50", long 66°40'02", at pedestrian bridge, 0.7 mi (1.1 km) downstream from Lago Dos Bocas and 6.6 mi (10.6 km) west of Florida plaza. DRAINAGE AREA.--169 mi2 (436 km2). This does not include 6.0 mi2 (15.5 km2) above Lago Garzas. PERIOD OF RECORD.--Water years 1970-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) NOV 01... 1050 -- 190 7.3 25.5 35 7.8 94 14 E700 670 68 18.3 FEB 27... 1115 73 230 7.4 24.0 .7 6.0 72 <10 <10 -- -- -- MAY 17... 1400 E500 190 6.9 25.5 62 4.7 58 <10 E500 E600 70 19.5 AUG 22... 1245 600 234 7.2 24.3 -- 7.4 89 <10 210 E120 83 23.2 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) NOV 01... 5.34 9.2 .5 1.87 -- <1.0 10.9 8.0 E.1 22.1 114 -- 35 FEB 27... -- -- -- -- 82 -- -- -- -- -- -- -- <10 MAY 17... 5.18 8.7 .5 2.02 64 <1.0 12.2 9.1 E.1 18.4 113 -- 24 AUG 22... 6.11 9.5 .5 1.86 82 -- 11.5 10.1 E.1 20.3 132 213 13 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) NOV 01... -- <.01 .7 .12 .71 .83 1.5 6.7 .070 <2 42.6 E12 <.11 FEB 27... .24 .03 .3 .14 .21 .35 .62 2.7 <.020 -- -- -- -- MAY 17... -- <.01 .7 <.01 -- .40 1.1 4.8 .070 <2 47.5 21 E.07 AUG 22... -- <.01 .2 .22 .36 .58 .79 3.5 .020 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 01... 1 <20.0 910 M 82 <.14 <2.6 <.43 E15 <.01 <16 <.04 FEB 27... -- -- -- -- -- -- -- -- -- -- -- -- MAY 17... M <20.0 1130 2 97 <.01 <3.0 <.40 <31 <.01 E9 .02 AUG 22... -- -- -- -- -- -- -- -- -- -- -- -- E -- Estimated value < -- Less than M -- Presence verified, not quantified 129 RIO GRANDE DE ARECIBO BASIN 50027600 RIO GRANDE DE ARECIBO NEAR SAN PEDRO, PR LOCATION.--Lat 18°23'55', long 66°41'29", Hydrologic Unit 21010002,on left side of old Hwy 10, 4.5 mi (7.24 km) north of Lago Dos Bocas Dam, 5.4 mi (8.69 km) from Plaza Rosario at Arecibo town and 3.8 mi (6.11 km) east from La Esperanza School. DRAINAGE AREA.--173.7 mi2 (449 km2), approximately, of which an undetermined amount does not contribute directly to surface runoff. PERIOD OF RECORD.--Feb. 1959 to Feb. 1962 yearly measurements only, May to September 2001. GAGE.--Water-stage recorder. Elevation of gage is 49.2 ft (15 m), from topographic map. REMARKS.--Records fair. Flow affected by Lago Dos Bocas Dam 4.9 mi (7.24 km) upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 47 584 e185 285 2 281 631 e225 434 3 239 402 e335 509 4 459 169 e707 226 5 308 293 e457 496 6 263 129 e525 391 7 232 66 e543 422 8 51 66 e127 207 9 103 185 e73 e593 10 135 398 e93 e848 11 178 306 e233 e574 12 195 371 e457 e415 13 467 621 e475 e513 14 384 528 e476 e314 15 411 718 e267 e488 16 243 169 e307 261 17 323 261 375 e234 370 18 382 344 67 e128 130 19 216 492 129 e175 428 20 55 570 61 e340 246 21 100 265 e58 e246 337 22 337 368 e139 e67 1070 23 202 270 e291 e651 766 24 337 289 e371 e165 292 25 196 325 e395 e84 406 26 176 357 e282 e265 484 27 352 325 e195 e516 570 28 210 82 e101 e681 705 29 554 172 e105 e682 761 30 205 223 e600 e540 364 31 70 --- e574 312 --- TOTAL --- 8339 9379 10571 13905 MEAN --- 278 303 341 464 MAX --- 570 718 707 1070 MIN --- 47 58 67 130 AC-FT --- 16540 18600 20970 27580 CFSM --- 1.60 1.74 1.96 2.67 IN. --- 1.79 2.01 2.26 2.98 e Estimated 130 RIO GRANDE DE ARECIBO BASIN 50027600 RIO GRANDE DE ARECIBO NEAR SAN PEDRO, PR--Continued O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND Gap indicates missing record 131 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR LOCATION.--Lat 18°25'22', long 66°41'58", Hydrologic Unit 21010002, 0.5 mi (0.8 km) upstream from Río Tanamá, 3.6 mi (5.8 km), south of Arecibo and 4.9 mi (7.9 km) above mouth, and 10.4 mi (16.7 km) downstream from Lago Dos Bocas. DRAINAGE AREA.--174 mi2 (451 km2), approximately, of which an undetermined amount does not contribute directly to surface runoff. PERIOD OF RECORD.--April 1982 to current year. GAGE.--Water-stage recorder. Elevation of gage is 30 ft (9 m), from topographic map. REMARKS.--Records poor. Flow regulated by Lago Dos Bocas Dam 10.4 mi (16.7 km) upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 282 632 74 55 e76 22 3.4 85 5.9 319 90 113 2 237 469 119 66 e100 115 2.9 161 32 489 88 266 3 196 534 117 13 24 3.6 26 187 175 274 242 292 4 283 524 115 17 18 7.3 73 129 213 183 492 184 5 386 476 138 69 75 35 3.0 171 239 98 258 240 6 319 487 104 98 75 74 2.9 160 92 114 357 239 7 391 303 104 99 82 146 9.6 1480 214 12 297 304 8 357 454 99 1.2 60 9.0 14 644 20 12 31 130 9 477 356 95 35 29 13 2.2 654 7.7 34 22 210 10 533 241 92 137 1.5 6.1 1.5 554 28 137 31 446 11 456 43 e97 29 6.9 3.1 30 820 32 203 131 316 12 508 105 e101 149 19 47 77 395 72 247 252 252 13 e281 267 e156 138 40 53 1.6 230 159 263 303 281 14 e299 200 155 80 18 4.3 1.4 137 321 407 288 276 15 273 191 124 5.5 2.6 37 1.7 296 238 456 113 268 16 358 332 117 60 9.9 23 13 315 163 239 193 176 17 487 326 13 5.4 28 8.8 9.8 185 125 223 113 229 18 757 118 6.9 68 88 3.7 9.5 193 157 72 30 51 19 683 255 37 96 3.9 23 83 233 319 22 78 183 20 1190 59 33 57 36 5.7 104 23 313 11 179 173 21 756 110 55 1.3 e13 50 72 6.5 212 21 121 150 22 e485 95 4.5 42 58 207 68 88 227 86 17 557 23 e892 36 3.1 32 14 25 1.9 145 151 190 442 478 24 e753 149 1.1 51 3.2 5.7 1.2 158 e167 201 55 290 25 667 145 .91 104 43 4.9 2.8 135 205 252 23 240 26 801 301 43 88 3.9 49 14 131 205 158 125 302 27 244 242 142 27 11 124 58 162 245 85 303 392 28 185 73 124 1.5 94 e20 9.1 217 54 6.1 430 415 29 338 92 114 20 --- e128 86 267 79 55 429 473 30 549 29 116 17 --- e186 81 239 103 447 327 285 31 665 --- 56 36 --- 13 --- 32 --- 387 165 --- TOTAL 15088 7644 2556.51 1697.9 1032.9 1452.2 863.5 8632.5 4573.6 5703.1 6025 8211 MEAN 487 255 82.5 54.8 36.9 46.8 28.8 278 152 184 194 274 MAX 1190 632 156 149 100 207 104 1480 321 489 492 557 MIN 185 29 .91 1.2 1.5 3.1 1.2 6.5 5.9 6.1 17 51 AC-FT 29930 15160 5070 3370 2050 2880 1710 17120 9070 11310 11950 16290 CFSM 2.80 1.46 .47 .31 .21 .27 .17 1.60 .88 1.06 1.12 1.57 IN. 3.23 1.63 .55 .36 .22 .31 .18 1.85 .98 1.22 1.29 1.76 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1982 - 2001, BY WATER YEAR (WY) MEAN 577 499 285 234 210 200 304 514 333 235 259 510 MAX 1984 1413 570 437 428 351 617 2000 683 374 474 1479 (WY) 1986 1986 1988 1988 1988 1985 1986 1986 1987 1987 1988 1996 MIN 171 123 72.4 54.8 36.9 46.8 28.8 178 69.3 62.7 82.8 99.9 (WY) 1995 1995 1995 2001 2001 2001 2001 1994 1994 1994 1994 1994 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1982 - 2001 ANNUAL TOTAL 96147.51 63480.21 ANNUAL MEAN 263 174 346 HIGHEST ANNUAL MEAN 729 1986 LOWEST ANNUAL MEAN 132 1994 HIGHEST DAILY MEAN 1190 Oct 20 1480 May 7 14800 May 18 1985 LOWEST DAILY MEAN .91 Dec 25 .91 Dec 25 .91 Dec 25 2000 ANNUAL SEVEN-DAY MINIMUM 19 Dec 19 9.0 Apr 5 9.0 Apr 5 2001 MAXIMUM PEAK FLOW 2270 May 7 45800 May 18 1985 MAXIMUM PEAK STAGE 9.47 May 7 18.22 May 18 1985 ANNUAL RUNOFF (AC-FT) 190700 125900 250700 ANNUAL RUNOFF (CFSM) 1.51 1.00 1.99 ANNUAL RUNOFF (INCHES) 20.56 13.57 27.02 10 PERCENT EXCEEDS 532 444 720 50 PERCENT EXCEEDS 207 114 230 90 PERCENT EXCEEDS 65 6.3 53 e Estimated 132 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR--Continued O N D 2000 J F M A M J J A S 2001 0.1 0.2 0.5 1 2 5 10 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 133 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR LOCATION.--Lat 18°18'02", long 66°46'58", Hydrologic Unit 21010001, on downstream side of left abutment of bridge on Highway 111, 1.2 mi (1.9 km) upstream from natural tunnel, 1.5 mi (2.4 km) northeast of Angeles, and 5.8 mi (9.3 km) northwest of Utuado. DRAINAGE AREA.--18.4 mi2 (47.7 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--June 1944 to June 1958 (daily stage and two to four measurements per month by Puerto Rico Water Resources Authority), November 1959 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 938.32 ft (286.000 m) above mean sea level. Datum of gage was increased by 3.00 ft (0.914 m) on Oct. 1978. REMARKS.--Records fair except those for estimated daily discharges, which are poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 68 203 36 25 25 20 12 17 24 30 113 88 2 73 103 35 25 24 22 12 15 22 25 49 46 3 67 95 34 25 22 20 15 14 48 24 52 60 4 63 74 33 24 21 18 21 14 36 24 35 87 5 59 70 33 24 21 18 19 14 32 31 28 58 6 58 67 32 24 21 18 25 278 24 24 75 125 7 154 64 32 24 31 18 19 161 22 23 36 68 8 75 62 31 23 21 17 15 97 21 22 29 51 9 62 60 30 23 18 17 14 93 20 22 27 56 10 61 58 30 22 17 16 13 267 20 142 39 71 11 64 56 30 22 17 16 13 144 20 51 107 51 12 56 64 30 23 18 16 13 82 22 49 60 101 13 54 60 31 23 17 16 12 64 35 31 33 84 14 52 52 30 23 17 17 12 141 22 29 59 61 15 75 51 33 23 18 17 14 111 20 25 47 55 16 113 50 32 27 17 16 15 80 25 23 34 46 17 87 48 30 27 17 15 14 70 73 31 34 49 18 63 46 29 23 17 15 14 60 86 39 32 45 19 165 45 27 22 16 15 14 57 40 29 83 42 20 177 44 27 22 16 16 19 42 30 25 66 64 21 108 43 27 22 17 15 25 31 26 24 37 96 22 179 43 26 21 34 15 24 31 25 24 33 56 23 257 42 26 21 21 18 37 28 37 27 63 58 24 176 41 25 21 22 51 28 26 47 25 36 77 25 112 39 25 20 22 24 68 25 43 28 35 50 26 86 38 40 20 20 16 98 24 35 55 52 67 27 77 37 43 22 19 14 38 26 28 67 52 97 28 80 37 28 36 19 14 21 25 32 30 45 59 29 68 36 26 40 --- 14 23 23 27 31 53 47 30 200 38 26 42 --- 13 27 25 29 31 67 44 31 92 --- 25 25 --- 12 --- 28 --- 25 80 --- TOTAL 3081 1766 942 764 565 549 694 2113 971 1066 1591 1959 MEAN 99.4 58.9 30.4 24.6 20.2 17.7 23.1 68.2 32.4 34.4 51.3 65.3 MAX 257 203 43 42 34 51 98 278 86 142 113 125 MIN 52 36 25 20 16 12 12 14 20 22 27 42 AC-FT 6110 3500 1870 1520 1120 1090 1380 4190 1930 2110 3160 3890 CFSM 5.40 3.20 1.65 1.34 1.10 .96 1.26 3.70 1.76 1.87 2.79 3.55 IN. 6.23 3.57 1.90 1.54 1.14 1.11 1.40 4.27 1.96 2.16 3.22 3.96 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1960 - 2001, BY WATER YEAR (WY) MEAN 81.7 69.0 43.3 30.2 26.0 25.0 35.6 57.1 44.2 36.2 47.6 78.5 MAX 195 159 121 71.0 50.8 71.2 142 193 117 65.7 110 208 (WY) 1990 1969 1966 1997 1996 1972 1969 1963 1999 1981 1979 1998 MIN 25.4 25.1 18.1 14.7 13.2 11.0 9.70 12.4 15.6 9.18 15.9 25.0 (WY) 1963 1995 1998 1998 1965 1984 1984 1977 1994 1994 1994 1994 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1960 - 2001 ANNUAL TOTAL 19914 16061 ANNUAL MEAN 54.4 44.0 48.0 HIGHEST ANNUAL MEAN 71.7 1999 LOWEST ANNUAL MEAN 20.7 1994 HIGHEST DAILY MEAN 424 Aug 23 278 May 6 3260 Sep 22 1998 LOWEST DAILY MEAN 20 Apr 28 12 Mar 31 5.4 Aug 4 1994 ANNUAL SEVEN-DAY MINIMUM 21 Apr 24 13 Mar 27 6.4 Jul 29 1994 MAXIMUM PEAK FLOW 1850 May 6 23500 Sep 22 1998 MAXIMUM PEAK STAGE 10.00 May 6 21.24 Sep 22 1998 INSTANTANEOUS LOW FLOW 11 Apr 2 5.4 Aug 4 1994 ANNUAL RUNOFF (AC-FT) 39500 31860 34740 ANNUAL RUNOFF (CFSM) 2.96 2.39 2.61 ANNUAL RUNOFF (INCHES) 40.26 32.47 35.41 10 PERCENT EXCEEDS 112 83 86 50 PERCENT EXCEEDS 36 30 33 90 PERCENT EXCEEDS 23 16 16 134 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 135 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED SEDIMENT DISCHARGE: January 1968 to current year. INSTRUMENTATION.--USDH-48 sediment sampler since October 1968. Automatic sediment sampler since 1990. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 20,400 mg/L November 27, 1968; Minimum daily mean, 1 mg/L several days during several years. SEDIMENT LOADS: Maximum daily mean, 240,000 tons (218,000 tonnes) September 22, 1998; Minimum daily mean, <0.01 ton ( <0.01 tonne) several days during several years. EXTREMES FOR CURRENT YEAR 2001.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 4,040 mg/L October 30, 2000; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 6,500 tons (5,897 tonnes) October 30, 2000; Minimum daily mean, 0.07 ton ( 0.06 tonne) several days. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) NOV 03... 1200 99 148 7.6 23.5 37 7.1 87 <10 25000 1000 54 13.9 FEB 26... 1015 21 169 7.5 21.4 3.0 9.4 110 <10 E40 E140 -- -- MAY 07... 1515 95 134 7.1 23.7 38 7.6 94 <10 2100 2200 45 11.9 SEP 12... 1143 44 162 6.9 24.8 -- 8.0 101 <10 E780 270 61 14.8 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) NOV 03... 4.66 7.0 .4 1.94 -- <1.0 9.9 6.9 .2 22.8 97 25.8 44 FEB 26... -- -- -- -- 52 -- -- -- -- -- -- -- <10 MAY 07... 3.81 5.8 .4 3.05 32 <1.0 11.4 7.6 <.2 17.3 80 20.6 17 SEP 12... 5.82 7.6 .4 2.16 52 -- 9.8 7.5 <.2 24.7 103 12.3 <10 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) NOV 03... .97 .01 1.0 .03 .24 .27 1.2 5.5 .040 <2 31.2 E9 <.11 FEB 26... -- <.01 .5 .01 -- <.20 -- -- <.020 -- -- -- -- MAY 07... -- <.01 1.6 .03 .35 .38 2.0 8.8 .030 <2 33.4 E17 <.11 SEP 12... -- <.01 .8 .02 -- <.20 -- -- <.020 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 03... 2 E12.8 890 M 59 <.14 <2.6 <.43 E18 <.01 <16 <.04 FEB 26... -- -- -- -- -- -- -- -- -- -- -- -- MAY 07... M <20.0 730 M 60 <.01 <2.6 <.43 <31 <.01 <16 <.02 SEP 12... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 136 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR WATER-QUALITY RECORDS SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 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 68 55 10 203 739 683 36 7 .66 2 73 158 35 103 269 77 35 7 .65 3 67 124 23 95 238 67 34 7 .65 4 63 113 19 74 152 30 33 7 .65 5 59 106 17 70 144 27 33 7 .65 6 58 99 16 67 136 25 32 7 .65 7 154 916 1080 64 128 22 32 8 .64 8 75 226 47 62 119 20 31 8 .64 9 62 41 7.1 60 111 18 30 8 .64 10 61 11 1.7 58 103 16 30 8 .65 11 64 63 13 56 95 14 30 8 .66 12 56 73 11 64 145 41 30 8 .66 13 54 16 2.3 60 99 17 31 8 .69 14 52 8 1.2 52 14 1.9 30 8 .68 15 75 165 62 51 8 1.2 33 8 .75 16 113 778 721 50 6 .88 32 9 .74 17 87 238 68 48 5 .66 30 9 .71 18 63 126 22 46 5 .65 29 9 .68 19 165 1030 1220 45 5 .65 27 5 .39 20 177 1430 2220 44 6 .65 27 1 .07 21 108 311 101 43 6 .65 27 1 .07 22 179 753 904 43 6 .66 26 1 .07 23 257 1380 2130 42 6 .66 26 1 .07 24 176 690 352 41 6 .65 25 1 .07 25 112 308 95 39 6 .65 25 1 .07 26 86 191 45 38 6 .64 40 128 36 27 77 155 32 37 6 .64 43 101 14 28 80 204 52 37 6 .64 28 78 5.9 29 68 144 27 36 7 .64 26 76 5.5 30 200 4040 6500 38 7 .68 26 74 5.2 31 92 269 68 --- --- --- 25 73 5.0 TOTAL 3081 --- 15902.3 1766 --- 1070.10 942 --- 84.46 137 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 25 71 4.8 25 40 2.7 20 4 .19 2 25 69 4.7 24 33 2.1 22 4 .25 3 25 68 4.5 22 25 1.5 20 6 .31 4 24 65 4.3 21 17 .96 18 8 .39 5 24 57 3.7 21 10 .60 18 10 .47 6 24 49 3.2 21 10 .53 18 9 .41 7 24 40 2.6 31 62 9.2 18 7 .35 8 23 32 2.0 21 116 6.7 17 6 .29 9 23 24 1.4 18 62 3.1 17 5 .24 10 22 15 .93 17 30 1.4 16 6 .27 11 22 8 .47 17 23 1.1 16 7 .31 12 23 6 .38 18 20 .95 16 8 .33 13 23 5 .33 17 23 1.1 16 7 .30 14 23 4 .28 17 26 1.2 17 6 .29 15 23 4 .23 18 29 1.4 17 6 .26 16 27 15 1.6 17 27 1.2 16 5 .21 17 27 27 2.2 17 24 1.1 15 4 .16 18 23 9 .54 17 21 .96 15 3 .12 19 22 6 .40 16 19 .83 15 2 .10 20 22 6 .35 16 17 .75 16 4 .17 21 22 6 .35 17 16 .76 15 6 .23 22 21 6 .34 34 54 5.4 15 7 .28 23 21 6 .37 21 15 .87 18 11 .60 24 21 7 .38 22 11 .64 51 157 46 25 20 7 .38 22 6 .34 24 29 2.2 26 20 7 .36 20 2 .13 16 18 .75 27 22 6 .38 19 3 .13 14 15 .58 28 36 46 5.3 19 3 .15 14 12 .46 29 40 64 11 --- --- --- 14 9 .35 30 42 69 8.8 --- --- --- 13 7 .23 31 25 47 3.2 --- --- --- 12 9 .30 TOTAL 764 --- 69.77 565 --- 47.80 549 --- 57.40 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 12 12 .40 17 40 1.9 24 33 2.2 2 12 15 .49 15 31 1.3 22 23 1.4 3 15 19 .78 14 22 .86 48 223 71 4 21 31 2.4 14 18 .70 36 64 7.6 5 19 30 2.1 14 15 .58 32 53 6.6 6 25 34 2.6 278 1030 3030 24 31 2.0 7 19 18 1.0 161 343 214 22 27 1.6 8 15 13 .53 97 424 269 21 24 1.4 9 14 11 .41 93 286 147 20 20 1.1 10 13 10 .34 267 1620 2370 20 17 .90 11 13 9 .31 144 494 235 20 14 .75 12 13 8 .28 82 31 6.9 22 33 3.8 13 12 8 .27 64 21 3.7 35 76 9.7 14 12 8 .27 141 682 732 22 26 1.5 15 14 8 .31 111 332 141 20 21 1.2 16 15 8 .30 80 163 35 25 33 3.4 17 14 6 .23 70 39 7.4 73 245 111 18 14 4 .16 60 87 15 86 465 258 19 14 2 .09 57 96 16 40 93 10 20 19 18 2.3 42 42 4.9 30 72 5.8 21 25 29 2.3 31 24 2.0 26 56 4.0 22 24 26 1.8 31 70 7.1 25 40 2.7 23 37 82 12 28 26 2.0 37 62 7.7 24 28 32 2.8 26 16 1.1 47 96 17 25 68 254 129 25 7 .46 43 79 9.7 26 98 323 191 24 6 .39 35 45 4.5 27 38 76 8.5 26 6 .42 28 27 2.0 28 21 47 2.8 25 8 .54 32 57 6.3 29 23 40 4.1 23 8 .53 27 35 2.5 30 27 62 5.1 25 14 1.1 29 32 2.5 31 --- --- --- 28 30 2.5 --- --- --- TOTAL 694 --- 374.97 2113 --- 7250.38 971 --- 559.85 138 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 30 22 1.8 113 685 870 88 304 134 2 25 14 .94 49 113 20 46 69 8.7 3 24 10 .65 52 151 41 60 133 34 4 24 7 .44 35 45 4.4 87 323 212 5 31 29 3.6 28 24 1.8 58 124 20 6 24 24 1.5 75 302 204 125 660 853 7 23 21 1.3 36 55 5.8 68 155 30 8 22 17 1.0 29 34 2.7 51 109 15 9 22 14 .80 27 22 1.6 56 88 13 10 142 1250 1830 39 57 10 71 197 61 11 51 112 26 107 544 605 51 116 16 12 49 117 33 60 140 29 101 520 650 13 31 34 3.0 33 27 2.4 84 253 87 14 29 35 3.1 59 198 92 61 105 17 15 25 19 1.3 47 78 12 55 102 18 16 23 9 .54 34 24 2.1 46 76 9.6 17 31 41 5.4 34 21 1.9 49 86 12 18 39 69 9.5 32 20 1.7 45 73 9.0 19 29 36 3.0 83 359 231 42 54 6.1 20 25 23 1.5 66 187 56 64 258 102 21 24 18 1.2 37 43 4.3 96 1010 1040 22 24 14 .90 33 24 2.2 56 114 18 23 27 10 .75 63 109 22 58 137 26 24 25 17 1.3 36 43 4.2 77 244 117 25 28 33 3.1 35 32 3.1 50 89 12 26 55 148 50 52 116 33 67 172 41 27 67 231 90 52 97 17 97 346 213 28 30 43 3.4 45 81 11 59 118 19 29 31 32 2.7 53 119 33 47 89 11 30 31 26 2.2 67 161 38 44 66 7.8 31 25 24 1.6 80 275 130 --- --- --- TOTAL 1066 --- 2085.52 1591 --- 2492.2 1959 --- 3812.2 YEAR 16061 33806.95 139 RIO GRANDE DE ARECIBO BASIN 50028400 RIO TANAMA AT CHARCO HONDO, PR LOCATION.--Lat 18°24'52", long 66°42'52", Hydrologic Unit 21010002 on right bank 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.--22.2 mi2 (57.5 km2). PERIOD OF RECORD.--April 1969 to June 1971, October 1981 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 60 ft (18 m), from topographic map. REMARKS.--Records poor. Diversion 0.8 mi (1.3 km) upstream for municipal supply of Arecibo. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 104 284 e75 e60 46 37 e31 58 e72 e56 e120 155 2 113 221 e70 e59 47 47 30 55 e60 e54 e90 127 3 134 e150 e68 e58 e44 42 33 51 e56 e53 e95 97 4 178 e130 e67 e57 e42 38 42 67 99 e53 e70 109 5 e140 127 e66 e56 e41 36 37 71 73 e64 e60 112 6 e120 109 e64 e55 e40 36 54 432 e60 e54 e125 136 7 191 e115 e62 e54 e39 35 60 664 e55 e52 e76 129 8 167 e110 e61 e53 54 e35 45 231 e52 e50 e62 91 9 121 e108 e61 e52 44 e34 42 263 e51 e50 e58 93 10 114 e102 e60 e52 e41 e33 37 613 e50 e200 e74 108 11 131 e100 e60 e51 e39 e32 34 406 50 e93 e160 116 12 119 e98 e59 e50 e40 e32 e32 184 50 e70 e110 81 13 128 e105 e58 e50 e41 e31 e30 125 76 e62 e68 172 14 122 e98 e58 e50 39 e31 37 169 137 e60 e105 95 15 143 e100 e57 e49 41 e32 35 276 62 e56 e90 85 16 176 e96 73 e49 40 e34 33 192 54 e52 e70 80 17 138 e92 72 63 36 e32 32 123 95 e64 e66 69 18 128 e93 66 56 39 31 32 100 128 e78 e66 88 19 336 e97 e64 54 37 32 31 99 102 e62 e130 76 20 337 e92 e62 e52 37 31 30 81 66 e56 e110 76 21 181 e89 e60 e51 37 34 44 76 56 e54 e74 114 22 280 e86 e59 e50 66 e32 44 70 54 e54 e68 111 23 e470 e84 e58 e49 47 36 48 81 54 e58 e110 102 24 409 e82 e57 e48 46 52 63 67 79 e54 e72 159 25 266 e81 e64 e47 46 84 112 63 107 e60 e70 162 26 188 80 87 e46 44 40 231 64 110 e98 e94 108 27 175 76 108 e45 39 36 191 96 62 e115 e100 145 28 171 78 73 e60 38 e35 75 125 60 e63 e86 131 29 152 e76 e68 73 --- e34 58 71 66 e65 77 93 30 289 e73 e64 106 --- e33 69 e60 e62 e64 100 84 31 208 --- e62 53 --- e32 --- e64 --- e56 89 --- TOTAL 5929 3232 2043 1708 1190 1139 1672 5097 2158 2080 2745 3304 MEAN 191 108 65.9 55.1 42.5 36.7 55.7 164 71.9 67.1 88.5 110 MAX 470 284 108 106 66 84 231 664 137 200 160 172 MIN 104 73 57 45 36 31 30 51 50 50 58 69 AC-FT 11760 6410 4050 3390 2360 2260 3320 10110 4280 4130 5440 6550 CFSM 8.62 4.85 2.97 2.48 1.91 1.66 2.51 7.41 3.24 3.02 3.99 4.96 IN. 9.94 5.42 3.42 2.86 1.99 1.91 2.80 8.54 3.62 3.49 4.60 5.54 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2001, BY WATER YEAR (WY) MEAN 169 137 85.8 62.7 51.4 44.8 65.6 127 93.5 67.2 84.7 141 MAX 335 260 219 167 106 76.1 141 371 236 120 168 448 (WY) 1990 1982 1982 1997 1996 1999 1986 1986 1999 1969 1998 1998 MIN 72.1 50.4 36.4 22.3 16.8 16.6 25.9 15.8 23.3 22.0 35.1 44.9 (WY) 1983 1995 1989 1989 1989 1988 1989 1989 1989 1989 1994 1994 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1969 - 2001 ANNUAL TOTAL 36420 32297 ANNUAL MEAN 99.5 88.5 92.7 HIGHEST ANNUAL MEAN 133 1999 LOWEST ANNUAL MEAN 46.9 1994 HIGHEST DAILY MEAN 606 Aug 23 664 May 7 6400 Sep 22 1998 LOWEST DAILY MEAN 41 Aug 21 30 Apr 2 4.2 May 28 1989 ANNUAL SEVEN-DAY MINIMUM 44 Aug 9 32 Mar 12 5.4 May 22 1989 MAXIMUM PEAK FLOW 3540 May 6 not determined Sep 22 1998 MAXIMUM PEAK STAGE 12.01 May 6 24.56 Sep 22 1998 ANNUAL RUNOFF (AC-FT) 72240 64060 67150 ANNUAL RUNOFF (CFSM) 4.48 3.99 4.18 ANNUAL RUNOFF (INCHES) 61.03 54.12 56.73 10 PERCENT EXCEEDS 175 153 181 50 PERCENT EXCEEDS 74 66 67 90 PERCENT EXCEEDS 55 36 30 e Estimated 140 RIO GRANDE DE ARECIBO BASIN 50028400 RIO TANAMA AT CHARCO HONDO, PR--Continued O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 141 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR LOCATION.--Lat 18°27'20", long 66°42'10", Hydrologic Unit 21010002, at bridge on unimproved road, about 500 ft (152 m) upstream from Central Cambalache, near Highway 2, 13.9 mi (22.4 km) downstream from Dos Bocas Reservoir, 1.9 mi (3.1 km) downstream from Río Tanamá junction, and 1.6 mi (2.6 km) southeast of Arecibo. DRAINAGE AREA.--200 mi2 (520 km2). PERIOD OF RECORD.--January 1963 to January 1965 (monthly measurements only), February 1965 to April 1969 (occasional measurements only), May 1969 to Sepetember 1983, October 1996 to September 1997. GAGE.--Water-stage recorder. Datum of gage is 3.73 ft (1.14 m) above mean sea level. REMARKS.--Records poor. Flow regulated by Lago Dos Bocas dam, 13.9 mi (22.4 km) upstream. Gage-height satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 447 885 149 114 133 58 51 132 76 278 162 235 2 433 666 205 126 142 172 43 210 86 507 188 351 3 356 741 207 65 70 56 62 276 242 322 267 360 4 467 678 205 61 60 51 132 201 281 246 528 276 5 549 553 231 128 123 71 49 237 311 147 353 311 6 473 573 197 154 123 99 61 260 152 181 399 310 7 555 424 201 157 135 208 73 2600 273 63 409 379 8 560 541 198 53 109 53 67 803 76 58 116 208 9 626 452 196 69 94 50 50 821 58 61 78 242 10 694 333 192 207 52 62 45 827 67 152 94 512 11 629 146 201 63 52 54 67 1100 60 286 192 381 12 685 173 199 207 73 80 135 569 92 295 349 304 13 475 336 238 174 78 111 47 398 175 342 361 352 14 462 291 256 146 73 49 44 251 403 487 363 354 15 450 245 218 57 51 71 42 483 276 559 215 323 16 544 388 220 107 59 70 52 470 214 337 244 249 17 681 385 98 56 59 47 47 321 183 237 190 267 18 1020 196 83 111 154 45 43 305 232 150 116 141 19 994 307 119 147 53 59 124 369 370 95 150 214 20 2070 140 107 102 78 48 166 130 344 74 267 217 21 1110 190 127 48 53 67 133 100 265 71 200 216 22 698 167 80 74 115 286 131 165 249 127 75 587 23 1380 98 74 85 73 83 65 253 188 234 487 537 24 1160 217 72 84 54 66 66 242 213 292 143 462 25 971 207 73 169 82 113 83 235 261 308 86 382 26 1140 362 104 130 53 92 193 208 288 230 214 398 27 450 321 228 90 51 183 229 230 292 167 389 527 28 338 156 191 63 139 73 87 349 120 103 508 529 29 497 175 178 82 --- 131 152 322 133 104 506 568 30 773 100 182 128 --- 281 152 334 144 452 410 414 31 928 --- 116 98 --- 69 --- 108 --- 436 242 --- TOTAL 22615 10446 5145 3355 2391 2958 2691 13309 6124 7401 8301 10606 MEAN 730 348 166 108 85.4 95.4 89.7 429 204 239 268 354 MAX 2070 885 256 207 154 286 229 2600 403 559 528 587 MIN 338 98 72 48 51 45 42 100 58 58 75 141 AC-FT 44860 20720 10210 6650 4740 5870 5340 26400 12150 14680 16470 21040 CFSM 3.65 1.74 .83 .54 .43 .48 .45 2.15 1.02 1.19 1.34 1.77 IN. 4.21 1.94 .96 .62 .44 .55 .50 2.48 1.14 1.38 1.54 1.97 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2001, BY WATER YEAR (WY) MEAN 806 741 530 347 286 301 353 539 452 366 435 691 MAX 1577 1529 1327 651 425 627 641 1192 1220 854 1269 1866 (WY) 1971 2000 1982 1997 1997 1972 1983 1980 1979 1979 1979 1979 MIN 404 201 150 108 85.4 95.4 89.7 188 139 189 218 271 (WY) 1983 1998 1998 2001 2001 2001 2001 1977 1977 1997 1974 1997 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1969 - 2001 ANNUAL TOTAL 141103 95342 ANNUAL MEAN 386 261 495 HIGHEST ANNUAL MEAN 691 1979 LOWEST ANNUAL MEAN 261 2001 HIGHEST DAILY MEAN 2070 Oct 20 2600 May 7 15900 Aug 31 1979 LOWEST DAILY MEAN 72 Aug 12 42 Apr 15 42 Apr 15 2001 ANNUAL SEVEN-DAY MINIMUM 91 Dec 20 56 Mar 14 56 Mar 14 2001 MAXIMUM PEAK FLOW 5000 May 7 Not determined Sep 22 1998 MAXIMUM PEAK STAGE 10.29 May 7 19.28 Sep 22 1998 INSTANTANEOUS LOW FLOW 50 Feb 26 1974 ANNUAL RUNOFF (AC-FT) 279900 189100 358300 ANNUAL RUNOFF (CFSM) 1.93 1.31 2.47 ANNUAL RUNOFF (INCHES) 26.25 17.73 33.60 10 PERCENT EXCEEDS 739 539 960 50 PERCENT EXCEEDS 307 192 349 90 PERCENT EXCEEDS 124 59 129 142 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR--Continued O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 143 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 Lago Dos Bocas, 1.9 mi (3.1 km) downstream from Rio Tanamá, and 1.6 mi (2.6 km) southeast of Arecibo. DRAINAGE AREA.--200 mi2 (520 km2), approximately and does not include 6.0 mi2 (15.6 km2) above Lago Garzas. PERIOD OF RECORD.--Water years 1963-66, 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) NOV 01... 1315 -- 239 6.9 25.1 33 8.7 102 12 590 490 90 27.8 FEB 09... 1430 E57 285 8.1 26.5 30 10.4 129 <10 350 E20 -- -- MAY 10... 1230 -- 249 7.5 25.0 71 6.8 83 16 E17000 6300 120 40.9 SEP 10... 0800 360 233 7.4 26.3 -- 6.5 81 <10 2400 580 99 29.3 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) NOV 01... 5.10 7.8 .4 1.83 -- <1.0 10.8 8.2 E.1 19.4 132 -- 39 FEB 09... -- -- -- -- 115 -- -- -- -- -- -- -- 28 MAY 10... 3.34 5.2 .2 1.74 105 <1.0 8.4 7.2 E.1 8.5 138 -- 96 SEP 10... 6.21 9.5 .4 2.07 87 -- 12.7 11.2 <.2 19.6 143 139 18 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) NOV 01... -- <.01 .8 .04 .46 .50 1.3 5.8 .060 <2 39.9 E12 .54 FEB 09... -- <.01 .5 .24 .96 1.2 1.7 7.4 <.020 -- -- -- -- MAY 10... .69 .01 .7 .02 .54 .56 1.3 5.6 .110 <2 47.1 E13 E.11 SEP 10... -- <.01 .5 .03 .17 .20 .71 3.1 <.020 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 01... 2 <20.0 1130 M 78 <.14 <2.6 <.43 E31 <.01 <16 <.02 FEB 09... -- -- -- -- -- -- -- -- -- -- -- -- MAY 10... 2 <20.0 2400 2 170 .02 <2.6 <.43 E16 <.01 <16 <.05 SEP 10... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 144 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 CHLOR- DANE, P,P'- P,P'- ENDO- ENDRIN TECH- DDD P,P'- DDT DI- DI- SULFAN WATER HEPTA- PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I UNFLTRD ETHION, CHLOR, DATE TIME TOTAL TOTAL TOTAL RECOVER TOTAL RECOVER TOTAL TOTAL TOTAL REC TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39516) (39330) (39350) (39360) (39365) (39370) (39570) (39380) (39388) (39390) (39398) (39410) MAY 10... 1230 <.1 <.013 <.1 <.007 <.006 <.009 <.02 <.006 <.015 <.014 <.01 <.014 CARBO- HEPTA- METH- METHYL PHENO- CHLOR MALA- OXY- PARA- PARA- TOX- THION EPOXIDE LINDANE THION, CHLOR, THION, MIREX, THION, APHENE, WATER 2,4-D, 2,4,5-T 2,4-DP SILVEX, DATE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL UNFLTRD TOTAL TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39420) (39340) (39530) (39480) (39600) (39755) (39540) (39400) (39786) (39730) (39740) (82183) (39760) MAY 10... <.009 <.006 <.03 <.01 <.01 <.01 <.01 <1 <.02 .24 <.01 <.04 <.01 145 Figure 14. Río Grande de Manatí basin. 146 RIO GRANDE DE MANATI BASIN 50030460 RIO OROCOVIS AT OROCOVIS, PR LOCATION.--Lat 18°13'25", long 66°23'34", Hydrologic Unit 21010001, on right bank, 0.4 mi (0.6 km) south of junction of Highways 155 and 156 in Orocovis, 2.1 mi (3.38 km) upstream from Río Botijas, and 250 ft (76 m) upstream from bridge on Highway 599. DRAINAGE AREA.--5.03 mi2 (13.03 km2). PERIOD OF RECORD.--April 1981 to September 1982, October 1988 to current year. GAGE.--Water-stage recorder. Elevation of gage is 500 ft (152 m), from topographic map. REMARKS.--Records poor. Low flow affected by diversions for water supply. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e4.3 172 e2.4 2.1 e2.7 e2.4 e1.1 e1.6 .96 e1.0 1.4 2.2 2 e7.4 167 e2.4 2.6 e2.7 e2.3 e1.1 e1.6 .97 e1.3 25 23 3 e11 e59 e2.4 3.8 e2.2 e2.0 e1.0 e1.4 1.5 e1.3 13 12 4 e11 e23 e2.4 3.3 e2.2 e1.9 e1.7 e1.4 1.0 1.1 3.9 4.2 5 e6.0 13 e2.3 e1.9 e2.2 e1.9 20 e1.1 .86 1.1 2.2 2.8 6 e3.0 9.1 e2.5 e1.9 e2.2 e1.9 12 37 .95 1.2 2.2 2.3 7 e2.5 10 e2.4 3.3 e2.7 e2.1 e5.4 60 .91 1.2 1.9 2.6 8 e16 8.0 e2.3 e1.9 2.7 e2.0 e3.2 9.9 .97 1.2 1.6 2.4 9 e16 6.6 2.5 e1.9 e2.2 e2.0 e3.4 7.7 .91 1.1 1.3 2.3 10 e12 5.8 2.5 e1.9 e2.2 e1.7 e2.4 32 .92 1.2 1.3 1.9 11 e10 5.4 2.5 e3.0 e2.7 e1.8 e2.2 33 1.0 1.2 1.3 2.0 12 e11 16 e2.6 4.6 e2.7 e1.8 e2.2 6.8 .93 1.2 1.3 1.7 13 e5.6 11 e2.8 4.2 e2.7 e1.7 e2.4 2.8 .90 1.2 1.2 1.7 14 e2.7 e6.7 e4.1 e3.6 e2.7 e1.7 e2.5 1.8 .91 1.2 1.3 1.7 15 e2.8 e5.6 e3.2 e4.6 e2.2 e1.4 e2.0 1.8 1.1 1.1 1.7 1.8 16 e26 5.9 e3.2 e3.6 e2.2 e1.4 e1.7 1.8 1.1 1.1 1.6 1.8 17 e42 5.1 e2.8 e3.0 e2.2 e1.3 e1.7 1.5 1.4 1.1 2.3 1.7 18 e30 4.1 e2.5 e3.4 e2.0 e1.3 e1.6 1.8 .97 1.6 1.9 2.5 19 e28 e3.9 e2.4 e3.1 e1.9 e1.4 e1.5 1.8 .79 1.4 1.9 2.5 20 e42 e3.6 e2.3 e2.1 e1.9 e1.3 e1.7 1.1 .76 1.2 2.0 23 21 e33 e3.8 e2.3 e2.0 e2.0 e1.8 e2.0 1.0 .76 1.1 2.5 10 22 e16 e3.4 e2.1 e2.0 4.5 e2.3 e2.9 1.2 .76 1.1 4.6 29 23 e37 2.9 e2.1 e2.0 2.3 4.3 e2.8 1.2 .82 1.1 40 17 24 e62 2.9 e2.1 e2.0 4.0 3.7 e2.0 1.3 .87 1.1 8.2 9.2 25 e50 e2.8 e2.0 e1.6 5.9 3.7 e1.9 1.0 .87 1.0 3.2 6.7 26 e30 e2.7 e2.1 e1.6 e3.8 2.8 e28 1.2 .80 1.1 2.3 3.9 27 e20 e2.6 e2.4 e2.6 e2.5 3.7 e5.8 .99 e.82 1.2 2.0 3.3 28 e16 2.5 2.4 3.8 e2.4 e1.8 e2.8 1.2 e1.3 1.2 7.3 2.7 29 e11 2.4 2.2 e7.7 --- e1.6 e2.6 1.2 3.9 3.4 3.8 2.1 30 e29 e2.3 2.2 e5.1 --- e1.2 e1.7 1.0 1.5 2.8 2.0 2.5 31 51 --- 2.1 e3.6 --- e1.2 --- .92 --- 1.5 2.1 --- TOTAL 644.3 569.1 76.5 93.8 74.6 63.4 123.3 220.11 32.21 40.6 148.3 182.5 MEAN 20.8 19.0 2.47 3.03 2.66 2.05 4.11 7.10 1.07 1.31 4.78 6.08 MAX 62 172 4.1 7.7 5.9 4.3 28 60 3.9 3.4 40 29 MIN 2.5 2.3 2.0 1.6 1.9 1.2 1.0 .92 .76 1.0 1.2 1.7 AC-FT 1280 1130 152 186 148 126 245 437 64 81 294 362 CFSM 4.13 3.77 .49 .60 .53 .41 .82 1.41 .21 .26 .95 1.21 IN. 4.77 4.21 .57 .69 .55 .47 .91 1.63 .24 .30 1.10 1.35 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1981 - 2001, BY WATER YEAR (WY) MEAN 17.4 11.1 6.43 6.28 4.23 1.96 5.05 13.1 4.73 3.09 4.70 23.6 MAX 58.0 39.9 17.9 34.3 15.7 3.47 21.0 45.9 17.1 9.07 12.3 83.0 (WY) 1990 2000 2000 1992 1996 2000 1993 1995 1999 1996 1989 1998 MIN 1.95 .93 .53 .77 .96 .90 .93 .86 .88 .88 1.03 .88 (WY) 1994 1998 1998 1995 1995 1994 1995 1997 1994 1994 1982 1994 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1981 - 2001 ANNUAL TOTAL 3042.1 2268.72 ANNUAL MEAN 8.31 6.22 8.39 HIGHEST ANNUAL MEAN 13.3 1999 LOWEST ANNUAL MEAN 1.49 1994 HIGHEST DAILY MEAN 172 Nov 1 172 Nov 1 1570 Sep 10 1996 LOWEST DAILY MEAN 1.5 Aug 17 .76 Jun 20 .20 Oct 4 1992 ANNUAL SEVEN-DAY MINIMUM 1.7 Aug 15 .80 Jun 19 .33 Oct 11 1992 MAXIMUM PEAK FLOW 1650 Nov 1 8890 Sep 10 1996 MAXIMUM PEAK STAGE 10.53 Nov 1 17.38 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 6030 4500 6080 ANNUAL RUNOFF (CFSM) 1.65 1.24 1.67 ANNUAL RUNOFF (INCHES) 22.50 16.78 22.66 10 PERCENT EXCEEDS 18 12 15 50 PERCENT EXCEEDS 3.0 2.2 2.1 90 PERCENT EXCEEDS 1.9 1.1 .85 e Estimated 147 RIO GRANDE DE MANATI BASIN 50030460 RIO OROCOVIS AT OROCOVIS, PR--Continued O N D 2000 J F M A M J J A S 2001 0.1 0.2 0.5 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 148 RIO GRANDE DE MANATI BASIN 50030700 RIO OROCOVIS NEAR OROCOVIS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°14'20", long 66°22'58", at flat low bridge about 300 ft (91 m) northwest of Highway 568, 1.0 mi (1.6 km) north of Orocovis plaza. DRAINAGE AREA.--10.1 mi2 (26.2 km2). PERIOD OF RECORD.--Water year 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 10... 1100 12 281 8.0 23.8 20 7.7 97 <10 3000 430 110 28.1 FEB 21... 1450 7.9 332 8.2 24.2 2.9 7.9 101 <10 200 E20 -- -- APR 27... 1250 5.7 341 8.5 26.1 2.8 8.0 104 <10 E53 E130 140 36.8 SEP 06... 1045 7.2 309 7.6 24.9 -- 7.8 100 <10 350 320 130 32.6 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 10... 10.8 12.3 .5 2.14 116 <1.0 7.8 13.3 E.1 33.9 178 5.81 11 FEB 21... -- -- -- -- 145 -- -- -- -- -- -- -- <10 APR 27... 12.6 14.7 .5 1.73 141 <1.0 9.1 18.5 E.1 34.5 213 3.24 <10 SEP 06... 11.8 13.9 .5 1.73 127 -- 8.0 18.5 E.1 31.1 194 3.79 <10 NITRO- CHRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) (00620) (00615) (00630) (00610) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) OCT 10... 1.09 .01 1.1 .02 <.20 -- -- .120 2 46.6 26 <.11 1 FEB 21... -- <.01 1.2 .03 <.20 -- -- .180 -- -- -- -- -- APR 27... -- <.01 1.4 <.01 .22 1.6 7.2 .230 <2 49.0 31 <.11 <1 SEP 06... -- <.01 .8 .03 <.20 -- -- .180 -- -- -- -- -- 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- DATE (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) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 10... <20.0 490 <1 33 <.14 <2.6 <.43 <31 <.01 <16 <.02 FEB 21... -- -- -- -- -- -- -- -- -- -- -- APR 27... <20.0 130 <1 14 <.01 <2.6 <.43 <31 <.01 <16 <.04 SEP 06... -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 149 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR LOCATION.--Lat 18°17'45", long 66°24'47", Hydrologic Unit 21010001, on right bank , 0.1 mi (0.2 km) downstream from Quebrada Perchas, 0.8 mi (1.3 km) upstream from Río Sana Muerto, and 2.2 mi (3.5 km) south of Morovis. DRAINAGE AREA.--55.2 mi2 (143.0 km2). PERIOD OF RECORD.--January 1965 to current year. GAGE.--Water-stage recorder and concrete control. Elevation of gage is 440 ft (134 m), from topographic map. Feb.2,1966 to Apr. 27, 1967, only staff gage readings twice daily. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Public water-supply pumpage,about 1,000 ft (305 m) above the station, influences low-flow discharges. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 151 660 69 33 39 41 17 14 16 16 11 12 2 123 1140 58 32 36 70 16 13 18 12 15 20 3 79 535 55 31 31 37 16 12 15 11 46 71 4 55 198 52 31 28 30 17 13 29 13 16 25 5 45 145 51 31 26 28 18 13 17 21 11 15 6 38 121 49 30 27 27 72 30 15 12 10 12 7 36 382 49 30 28 26 31 411 14 9.6 13 11 8 91 207 48 28 25 26 21 115 13 9.0 10 10 9 70 137 47 27 23 24 21 111 13 8.6 9.8 9.6 10 44 116 48 27 23 23 19 72 12 8.4 14 9.1 11 37 104 47 26 34 21 19 87 11 8.4 12 8.2 12 33 101 44 28 32 21 19 46 11 8.9 10 9.2 13 85 111 47 27 35 20 19 34 11 9.8 8.7 9.4 14 44 95 44 31 26 19 24 28 12 9.1 8.0 7.6 15 35 93 69 32 28 19 18 26 14 8.6 13 8.1 16 53 84 64 27 28 18 16 23 24 8.0 10 9.2 17 60 80 86 29 28 18 15 21 29 7.5 21 11 18 57 76 83 26 24 17 14 22 29 8.8 33 9.7 19 296 74 56 25 22 17 14 33 17 11 15 19 20 153 72 50 24 24 18 14 23 12 10 10 12 21 87 73 44 24 23 21 19 18 11 9.5 8.7 44 22 96 90 43 23 71 26 39 18 9.8 7.8 9.3 e201 23 194 74 46 23 52 53 42 17 9.9 11 165 e74 24 175 67 40 23 44 75 30 17 13 11 68 e35 25 99 66 40 23 109 34 21 16 12 9.9 27 e22 26 71 65 39 21 69 23 22 16 16 8.9 18 e21 27 57 63 37 28 51 22 19 16 12 8.9 14 e18 28 50 61 38 47 37 21 15 16 11 8.0 13 e15 29 49 59 34 98 --- 20 15 16 11 8.9 32 e13 30 81 58 32 132 --- 18 14 16 14 51 17 e12 31 176 --- 33 53 --- 17 --- 15 --- 18 13 --- TOTAL 2720 5207 1542 1070 1023 850 656 1328 451.7 363.6 681.5 753.1 MEAN 87.7 174 49.7 34.5 36.5 27.4 21.9 42.8 15.1 11.7 22.0 25.1 MAX 296 1140 86 132 109 75 72 411 29 51 165 201 MIN 33 58 32 21 22 17 14 12 9.8 7.5 8.0 7.6 AC-FT 5400 10330 3060 2120 2030 1690 1300 2630 896 721 1350 1490 CFSM 1.59 3.14 .90 .63 .66 .50 .40 .78 .27 .21 .40 .45 IN. 1.83 3.51 1.04 .72 .69 .57 .44 .89 .30 .25 .46 .51 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1965 - 2001, BY WATER YEAR (WY) MEAN 149 145 110 81.7 63.8 61.7 99.0 149 59.6 44.2 52.2 109 MAX 1037 491 522 228 179 226 412 915 173 157 435 432 (WY) 1971 1971 1966 1997 1969 1972 1969 1985 1987 1979 1979 1996 MIN 24.0 11.4 8.65 10.4 15.3 12.7 8.80 15.7 6.75 5.54 9.70 6.87 (WY) 1978 1995 1995 1995 1994 1984 1995 1994 1994 1994 1984 1994 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1965 - 2001 ANNUAL TOTAL 26233.5 16645.9 ANNUAL MEAN 71.7 45.6 93.4 HIGHEST ANNUAL MEAN 248 1971 LOWEST ANNUAL MEAN 24.2 1994 HIGHEST DAILY MEAN 1140 Nov 2 1140 Nov 2 17100 May 18 1985 LOWEST DAILY MEAN 9.2 Aug 14 7.5 Jul 17 3.5 May 1 1995 ANNUAL SEVEN-DAY MINIMUM 10 Aug 8 8.6 Jul 11 4.0 Jul 22 1994 MAXIMUM PEAK FLOW 7650 Nov 2 48000 May 18 1985 MAXIMUM PEAK STAGE 8.34 Nov 2 17.89 May 18 1985 ANNUAL RUNOFF (AC-FT) 52030 33020 67700 ANNUAL RUNOFF (CFSM) 1.30 .83 1.69 ANNUAL RUNOFF (INCHES) 17.68 11.22 23.00 10 PERCENT EXCEEDS 148 86 170 50 PERCENT EXCEEDS 48 24 48 90 PERCENT EXCEEDS 14 10 19 e Estimated 150 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR--Continued O N D 2000 J F M A M J J A S 2001 1 2 5 10 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 151 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1968 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 12... 1035 32 281 7.7 25.7 23 8.4 104 <10 560 E150 110 26.0 FEB 21... 1300 23 298 8.2 24.9 3.0 8.8 109 <10 <10 E60 -- -- APR 24... 1040 30 280 7.8 24.8 -- 8.5 104 -- 240 E130 110 26.5 SEP 06... 1315 12 246 7.3 29.5 -- 7.9 105 <10 310 E54 98 23.6 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 12... 10.5 12.3 .5 2.18 113 <1.0 8.2 22.8 <.2 28.3 178 15.3 22 FEB 21... -- -- -- -- 120 -- -- -- -- -- -- -- <10 APR 24... 11.0 15.1 .6 1.96 107 <1.0 7.7 16.6 E.1 25.2 168 13.4 -- SEP 06... 9.47 11.8 .5 1.99 92 -- 7.9 15.2 E.1 24.3 149 4.83 14 NITRO- CHRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, IRON, LEAD, GEN, GEN, GEN, MONIA + PHOS- TOTAL TOTAL WATER TOTAL TOTAL TOTAL TOTAL NITRITE NO2+NO3 AMMONIA ORGANIC PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) AS FE) AS PB) (00615) (00630) (00610) (00625) (00665) (01002) (01007) (01022) (01027) (01034) (01042) (01045) (01051) OCT 12... <.01 .7 .15 <.20 .080 <2 49.1 33 <.11 2 <20.0 650 <1 FEB 21... <.01 .4 .02 <.20 .040 -- -- -- -- -- -- -- -- APR 24... <.01 .3 .02 <.20 .050 <2 46.6 27 <.11 <1 <20.0 230 <1 SEP 06... <.01 .6 .05 <.20 .050 -- -- -- -- -- -- -- -- MANGA- METHY- NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 12... 42 <.14 <2.6 <.43 <31 <.01 <16 .02 FEB 21... -- -- -- -- -- -- -- -- APR 24... 21 <.01 <2.6 <.43 <31 <.01 <16 .03 SEP 06... -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 152 RIO GRANDE DE MANATI BASIN 50032290 LAGO EL GUINEO AT DAMSITE NEAR VILLALBA, PR LOCATION.--Lat 18°09'41", long 66°31'36", Hydrologic Unit 21010001, at damsite on Río Toro Negro, 3.0 mi (4.8 km) northwest from Villalba plaza and 1.9 mi (3.1 km) northeast of Cerro Maravillas. The reservoir itself fixes the territorial limits between the Municipality of Ciales and Orocovis. DRAINAGE AREA.--1.64 mi2 (4.25 km2). ELEVATION RECORDS PERIOD OF RECORD.--May 1988 to current year. Prior to October 1994, published as Lago El Guineo at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago El Guineo was completed in 1931. It provides a maximum storage of approximately 2,180 ac-ft (2.688 hm3) for power and irrigation. Waters are discharged through an outlet power tunnel into the Río Toro Negro and coveyed to the head water works of Toro Negro Hydroelectric Plant No.2, for energy generation at Toro Negro Hydroelectric plant No.1, and are discharged into the Guayabal Reservoir to be later used for irrigation at South Coast Irrigation System. The dam is rockfill with a vertical concrete corewall, rock toes, and riprap facing of upstream slope, with a total length of 565 ft (172 m), a maximum structural height of 125 ft (38 m) to top of corewall. At a maximum reservoir water surface elevation the uncontrolled morning-glory tunnel spillway crest has an elevation of 2,960 ft (902 m) above mean sea level and a design capacity of 7,000 ft3/s. The dam is owned by Puerto Rico Electric Power Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,964.40 ft (903.55 m), Sept, 22 1998; minimun elevation, 2,919.79 ft (899.95 m), May 27, 1988. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 2,960.86 ft (902.47 m), Nov. 1; minimun elevation,2,927.75 ft (892.38 m), June 12. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 2,872 0 2,950 1,308 2,919 361 2,961 1,852 2,925 491 2,966 2,180 2,943 1,029 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2950.64 2960.86 2957.99 2957.53 2955.19 2948.67 2940.25 2936.86 2933.84 2932.29 2932.78 2945.07 2 2951.19 2960.17 2958.03 2957.50 2955.14 2947.92 2939.38 2936.05 2933.91 2932.39 2932.94 2945.34 3 2952.81 2959.77 2958.07 2957.46 2955.09 2947.85 2938.54 2935.15 2934.81 2931.44 2933.32 2945.66 4 2952.97 2958.84 2958.10 2957.42 2955.02 2947.76 2937.83 A 2935.08 2931.56 2933.15 2945.64 5 2952.97 2958.84 2958.12 2957.39 2954.96 2947.11 2937.30 A 2933.76 2930.60 2933.33 2945.68 6 2953.65 2958.75 2958.16 2957.34 2954.91 2946.33 2936.83 A 2932.81 2929.39 2933.54 2945.55 7 2955.78 2958.71 2958.17 2957.30 2954.86 2945.58 2936.79 A 2931.82 2929.49 2933.68 2946.27 8 2956.32 2958.73 2958.19 2957.26 2954.79 2944.82 2935.17 A 2930.77 2929.57 2933.84 2948.53 9 2956.39 2958.48 2957.54 2957.22 2954.73 2944.73 2934.17 A 2930.82 2928.86 2933.96 2949.02 10 2956.72 2958.13 2957.55 2957.18 2954.65 2944.63 2933.36 A 2930.85 2928.97 2934.08 2949.21 11 2956.64 2958.30 2957.57 2957.13 2954.60 2944.54 2932.67 A 2929.71 2929.26 2934.15 2949.29 12 2956.95 2958.50 2957.58 2957.09 2954.54 2943.73 2932.60 2941.38 2928.52 2932.18 2934.32 2949.28 13 2956.74 2958.16 2957.58 2957.05 2954.47 2943.10 2932.53 2941.60 2928.55 2932.55 2934.42 2949.27 14 2956.23 2958.38 2957.59 2957.00 2954.41 2942.28 2932.46 2941.79 2928.56 2936.06 2934.62 2949.34 15 2955.82 2958.68 2957.62 2956.95 2953.77 2941.40 2932.37 2941.15 2928.60 2936.78 2934.74 2949.57 16 2957.27 2958.95 2957.65 2956.96 2953.72 2941.26 2932.29 2940.52 2928.65 2937.10 2934.84 2949.76 17 2957.26 2959.13 2957.64 2956.81 2953.65 2941.10 2932.21 2940.14 2928.88 2937.35 2934.96 2950.44 18 2957.12 2959.26 2957.64 2956.75 2953.58 2940.94 2932.07 2939.54 2929.09 2936.79 2935.05 2950.54 19 2956.89 2959.37 2957.64 2956.69 2953.50 2940.79 2931.98 2939.67 2929.11 2936.14 2935.30 2950.60 20 2956.78 2959.47 2957.64 2956.64 2952.97 2940.67 2931.98 2939.72 2929.11 2935.39 2935.41 2951.28 21 2956.26 2959.61 2957.64 2956.59 2952.90 2940.05 2931.98 2938.95 2929.25 2933.87 2935.51 2951.28 22 2956.00 2959.72 2957.62 2956.54 2952.27 2940.14 2932.00 2938.16 2929.50 2933.26 2939.15 2951.22 23 2957.12 2959.82 2957.61 2956.50 2951.60 2940.56 2931.96 2937.38 2930.73 2933.47 2941.10 2953.98 24 2957.03 2959.90 2957.59 2956.46 2951.60 2942.01 2931.90 2937.03 2930.96 2932.75 2941.59 2954.48 25 2957.64 2959.97 2957.57 2956.41 2951.53 2941.42 2931.81 2936.14 2931.38 2932.96 2942.56 2954.23 26 2957.56 2960.02 2957.62 2956.19 2950.84 2941.41 2938.61 2936.17 2931.56 2932.36 2943.05 2954.09 27 2957.70 2959.58 2957.63 2956.14 2950.13 2941.40 2938.05 2936.20 2931.73 2932.57 2943.47 2954.07 28 2957.26 2959.21 2957.61 2956.09 2949.40 2940.81 2938.78 2936.24 2931.86 2932.74 2943.79 2954.01 29 2957.03 2958.85 2957.59 2956.12 --- 2940.75 2938.78 2935.44 2931.98 2933.17 2944.07 2953.74 30 2956.79 2958.44 2957.59 2956.10 --- 2940.38 2937.45 2934.51 2932.17 2933.42 2944.47 2953.96 31 2956.92 --- 2957.56 2955.50 --- 2940.32 --- 2933.79 --- 2932.59 2944.74 --- MAX 2957.70 2960.86 2958.19 2957.53 2955.19 2948.67 2940.25 --- 2935.08 2937.35 2944.74 2954.48 MIN 2950.64 2958.13 2957.54 2955.50 2949.40 2940.05 2931.81 --- 2928.52 2928.86 2932.78 2945.07 A No gage-height record 153 RIO GRANDE DE MANATI BASIN 50032290 LAGO EL GUINEO AT DAMSITE NEAR VILLALBA, PR--Continued O N D 2000 J F M A M J J A S 2001 2925 2930 2935 2940 2945 2950 2955 2960 2965 ELEVATION, IN FEET Gap indicates missing record 154 RIO GRANDE DE MANATI BASIN 50032590 LAGO DE MATRULLAS AT DAMSITE NEAR OROCOVIS, PR LOCATION.--Lat 18°12'46", long 66°28'50", Hydrologic Unit 21010001, in shelter house at damsite, and 5.8 mi (9.3 km) southwest of Orocovis. DRAINAGE AREA.--4.46 mi2 (11.55 km2). ELEVATION RECORDS PERIOD OF RECORD.--May 1988 to current year. Prior to October 1994, published as Lago de Matrullas at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Matrullas was completed in 1934. The dam is an earthfill structure about 120 ft (37 m) height, a top width of 30 ft (9 m) and a length of 710 ft (216 m), and has a maximum storage capacity of about 4,274 ac-ft (5.220 hm3) at top of dam elevation. The Matrullas Dam is owned by the Puerto Rico Electric Power Authority and is part of the Toro Negro Hydroelectric Project; a project developed by the P.R.E.P.A. for the primary purpose of generating electric power. Discharges from the Power Plants are collected by the Jacaguas River which flows into Guayabal Dam, at which dam they are regulated for irrigation of lands served by the Juana Díaz Canal. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,419.90 ft (737.58 m), Sept. 10, 1996; minimum elevation,2,375.55 ft (724.06 m), Sept. 24, 25, 1994. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 2,418.75 ft (737.24 m), Nov. 01; minimum elevation,2,406.05 ft (733.36 m), Apr.26. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 2,338 2 2,399 1,845 2,360 302 2,420 3,331 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2415.19 2416.25 2415.43 2415.43 2414.21 2412.88 2409.56 2408.75 2414.28 2414.49 2410.77 A 2 2415.17 2415.80 2415.53 2415.26 2414.33 2412.71 2409.31 2408.53 2414.41 2414.37 2410.58 2408.64 3 2415.22 2415.59 2415.54 2415.18 2414.45 2412.83 2409.06 2408.30 2414.58 2414.20 2410.42 A 4 2415.21 2415.47 2415.41 2415.09 2414.55 2412.92 2408.90 2408.08 2414.24 2414.34 2410.11 2409.35 5 2415.22 2415.60 2415.37 2414.99 2414.46 2412.72 2409.04 2408.19 2413.93 2414.18 2409.82 A 6 2415.23 2415.63 2415.32 2415.16 2414.41 2412.51 2408.85 2413.58 2413.77 2414.01 2409.56 A 7 2415.47 2415.60 2415.28 2415.31 2414.35 2412.32 2408.97 2414.71 2413.60 2413.72 A 2410.17 8 2415.71 2415.60 2415.29 2415.39 2414.12 2412.10 2408.56 2415.49 2413.42 2413.42 2409.08 A 9 2415.53 2415.58 2415.19 2415.22 2413.93 2411.89 2408.34 2415.28 2413.55 2413.20 2408.88 2410.43 10 2415.46 2415.55 2415.41 2415.08 2414.05 2411.98 2408.11 2415.36 2413.67 2413.01 2408.63 2410.34 11 2415.54 2415.62 2415.34 2414.94 2414.16 2412.05 2407.89 2415.18 2413.49 2412.84 A 2410.25 12 2415.59 2415.94 2415.33 2414.85 2414.01 2411.81 2407.64 2415.02 2413.29 2412.74 2408.85 2410.16 13 2415.46 2415.61 2415.28 2414.98 2413.85 2411.58 2407.77 2415.23 2413.12 2412.57 A 2410.01 14 2415.25 2415.57 2415.29 2415.14 2413.68 2411.36 2407.87 2415.08 2412.93 2412.34 A 2409.89 15 2415.20 2415.49 2415.29 2415.29 2413.51 2411.10 2407.97 2414.99 2412.74 2412.48 2408.14 2410.08 16 2415.48 2415.48 2415.49 2415.22 2413.38 2410.86 2408.06 2414.88 2412.86 2412.59 A 2409.84 17 2415.82 2415.48 2415.50 2415.10 2413.49 2410.95 2407.67 2414.63 2413.08 A 2407.54 2409.70 18 2415.54 2415.59 2415.37 2414.95 2413.56 2411.03 2407.43 2414.60 2412.90 2412.22 A A 19 2415.65 2415.58 2415.29 2414.81 2413.68 2410.79 2407.14 2414.81 2412.70 2412.03 2407.92 2409.39 20 2415.64 2415.58 2415.24 2414.95 2413.50 2410.55 2406.88 2414.96 2412.47 A A A 21 2415.46 2415.48 2415.18 2415.09 2413.34 2410.24 2406.79 2414.83 2412.26 2411.53 2407.41 2409.08 22 2415.49 2415.47 2415.13 2414.94 2413.23 2410.40 2406.94 2414.69 2412.11 A 2407.55 2409.76 23 2415.65 2415.66 2415.33 2414.80 2413.10 2410.31 2406.69 2414.55 2412.38 A A 2410.24 24 2415.64 2415.58 2415.42 2414.65 2413.36 2410.64 2406.52 2414.39 2412.51 A 2408.38 2410.26 25 2415.88 2415.58 2415.45 2414.50 2413.58 2410.53 2406.26 2414.24 2412.44 A 2408.75 2410.08 26 2415.65 2415.58 2415.30 2414.33 2413.41 2410.32 2408.94 2414.38 2412.26 A A 2409.90 27 2415.65 2415.46 2415.21 2414.58 2413.24 2410.10 2408.83 2414.62 2412.06 2411.00 2408.82 2409.66 28 2415.47 2415.42 2415.14 2414.70 2413.07 2409.86 2409.02 2414.79 2412.25 2411.09 A A 29 2415.51 2415.39 2415.10 2414.82 --- 2409.63 2409.15 2414.63 2414.03 2411.40 2408.48 2409.39 30 2415.79 2415.51 2415.27 2414.74 --- 2409.38 2408.95 2414.56 2414.31 2411.20 2408.29 2409.57 31 2415.63 --- 2415.38 2414.52 --- 2409.48 --- 2414.41 --- 2411.99 2408.10 --- MAX 2415.88 2416.25 2415.54 2415.43 2414.55 2412.92 2409.56 2415.49 2414.58 --- --- --- MIN 2415.17 2415.39 2415.10 2414.33 2413.07 2409.38 2406.26 2408.08 2412.06 --- --- --- A No gage-height record 155 RIO GRANDE DE MANATI BASIN 50032590 LAGO DE MATRULLAS AT DAMSITE NEAR OROCOVIS, PR--Continued O N D 2000 J F M A M J J A S 2001 2406 2408 2410 2412 2414 2416 2418 ELEVATION, IN FEET Gap indicates missing record 156 RIO GRANDE DE MANATI BASIN 50034000 RIO BAUTA NEAR OROCOVIS, PR LOCATION.--Lat 18°14'10", long 66°27'18", Hydrologic Unit 21010001, on left bank, at bridge on Highway 157 (12.1 km), and 4.2 mi (6.8 km) west of Orocovis. DRAINAGE AREA.--16.7 mi2 (43.3 km2). PERIOD OF RECORD.--February 1959 to April 1966 (annual low-flow measurements only), February to September 1969 (occasional measurements only), October 1969 to September 1982, October 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 772.82 ft (235.556 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 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 28 380 21 14 11 9.6 8.1 9.8 11 22 8.8 10 2 35 403 19 14 11 9.6 8.1 9.6 11 15 25 129 3 43 306 19 14 10 9.0 8.1 9.0 21 12 23 88 4 44 125 18 14 9.8 8.5 9.6 8.8 13 12 11 29 5 32 79 17 13 9.9 8.4 89 8.6 11 11 9.4 17 6 24 59 17 13 10 8.6 54 136 11 11 8.8 62 7 22 56 17 14 11 8.9 18 388 9.4 9.7 7.9 115 8 54 46 16 13 11 8.9 13 162 9.1 8.9 7.4 98 9 54 40 16 13 10 8.6 13 145 8.8 8.3 7.7 45 10 45 35 16 13 10 8.3 11 177 8.6 8.2 7.3 24 11 42 31 16 14 11 8.3 13 151 8.4 8.1 7.2 18 12 43 155 17 15 11 8.3 11 61 8.0 22 6.9 15 13 31 110 17 15 11 8.1 11 34 7.9 13 6.7 14 14 24 56 19 14 10 8.0 11 23 7.9 9.3 6.7 13 15 25 46 24 15 10 7.6 10 20 7.8 8.6 7.0 55 16 76 39 22 14 e10 7.5 9.7 16 8.1 8.2 6.9 40 17 111 34 22 15 10 7.3 9.3 14 46 8.0 8.8 19 18 85 31 19 14 9.5 7.3 9.2 16 19 9.6 9.7 17 19 82 30 18 14 9.3 7.4 9.1 19 10 9.3 8.3 15 20 112 28 17 13 9.3 7.7 9.1 13 8.7 8.1 7.3 61 21 92 28 16 13 9.1 9.1 10 12 8.2 8.0 7.5 128 22 54 29 16 13 16 11 12 11 8.5 9.1 10 134 23 99 34 15 13 11 46 12 12 18 9.8 154 119 24 156 29 15 13 14 31 10 11 12 9.8 28 48 25 131 25 15 12 25 23 10 11 10 8.3 52 26 26 86 24 15 12 13 12 71 10 9.5 8.2 35 18 27 63 22 15 13 10 20 e48 12 8.5 8.2 14 15 28 53 21 15 17 9.8 10 e15 13 41 7.8 18 13 29 42 21 15 30 --- 9.4 12 11 124 17 16 12 30 82 21 15 25 --- 8.7 10 10 68 18 11 11 31 198 --- 14 12 --- 8.4 --- 11 --- 9.9 9.8 --- TOTAL 2068 2343 533 451 312.7 354.5 544.3 1544.8 553.4 336.4 547.1 1408 MEAN 66.7 78.1 17.2 14.5 11.2 11.4 18.1 49.8 18.4 10.9 17.6 46.9 MAX 198 403 24 30 25 46 89 388 124 22 154 134 MIN 22 21 14 12 9.1 7.3 8.1 8.6 7.8 7.8 6.7 10 AC-FT 4100 4650 1060 895 620 703 1080 3060 1100 667 1090 2790 CFSM 3.99 4.68 1.03 .87 .67 .68 1.09 2.98 1.10 .65 1.06 2.81 IN. 4.61 5.22 1.19 1.00 .70 .79 1.21 3.44 1.23 .75 1.22 3.14 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2001, BY WATER YEAR (WY) MEAN 83.5 57.0 29.4 21.7 17.0 15.1 26.2 49.5 20.2 15.5 21.5 113 MAX 392 205 108 83.4 43.5 59.9 80.2 179 78.6 104 152 1104 (WY) 1971 1971 1971 1992 1998 1972 1980 1981 1979 1979 1979 1996 MIN 14.6 7.12 4.29 3.66 5.70 4.18 4.92 4.24 3.59 3.22 3.97 3.55 (WY) 1994 1995 1995 1995 1994 1994 1995 1994 1994 1994 1994 1994 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1969 - 2001 ANNUAL TOTAL 12781.2 10996.2 ANNUAL MEAN 34.9 30.1 39.1 HIGHEST ANNUAL MEAN 117 1996 LOWEST ANNUAL MEAN 6.56 1994 HIGHEST DAILY MEAN 403 Nov 2 403 Nov 2 19500 Sep 10 1996 LOWEST DAILY MEAN 7.4 Jul 28 6.7 Aug 13 2.8 Jul 23 1994 ANNUAL SEVEN-DAY MINIMUM 7.8 Jul 22 7.0 Aug 10 2.8 Jul 23 1994 MAXIMUM PEAK FLOW 1960 Nov 1 28200 Sep 22 1998 MAXIMUM PEAK STAGE 11.81 Nov 1 25.93 Sep 22 1998 INSTANTANEOUS LOW FLOW 6.1 Aug 14 2.6 Jul 26 1994 ANNUAL RUNOFF (AC-FT) 25350 21810 28350 ANNUAL RUNOFF (CFSM) 2.09 1.80 2.34 ANNUAL RUNOFF (INCHES) 28.47 24.49 31.83 10 PERCENT EXCEEDS 76 69 69 50 PERCENT EXCEEDS 19 13 14 90 PERCENT EXCEEDS 9.0 8.2 5.7 e Estimated 157 RIO GRANDE DE MANATI BASIN 50034000 RIO BAUTA NEAR OROCOVIS, PR--Continued O N D 2000 J F M A M J J A S 2001 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 158 RIO GRANDE DE MANATI BASIN 50035000 RIO GRANDE DE MANATI AT CIALES, PR LOCATION.--Lat 18°19'26", long 66°27'36", Hydrologic Unit 21010001, on left bank, 1.6 mi (2.6 km) upstream from Hwy 145 bridge, 0.8 mi (1.3 km) downstream from Quebrada Saliente, 0.9 mi (1.4 km) upstream from Quebrada Cojo Valés, and 1.2 mi (1.9 km) southeast of Ciales. DRAINAGE AREA.--128 mi2 (332 km2), excludes 6.0 mi2 (15.5 km2), the runoff from which is diverted through El Guineo and Matrullas reservoirs. PERIOD OF RECORD.--September 1946 to September 1953, May 1956 to December 1957 (unpublished, available in files of Caribbean District Office), February 1959 to September 1960 (monthly discharge measurements only), October 1960 to current year. Equivalent record from January 1971 to December 1972 published as 50035200 Río Grande de Manatí at Highway 145 at Ciales at site 1.6 mi (2.6 km) downstream, drainage area 132 mi2 (342 km2). GAGE.--Water-stage recorder. Elevation of gage is 140 ft (43 m), from topographic map. Prior to Apr. 1, 1962, staff gage, read twice daily, at site 100 ft (30 m) upstream at same datum. January 1971 to December 1972 at site 1.6 mi (2.6 km) downstream at different datum. Since October 1, 1997, 2.0 ft (0.6 m) were added to gage datum. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate gage heights of major floods, pointed out by local residents are as follows: August 1899, 50 ft (15 m), September 1928, 36 ft (11 m), and September 1932, 34 ft (10 m) at site 1.6 mi (2.6 km) upstream. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 432 569 152 89 93 55 42 46 44 e111 e49 e52 2 398 672 135 93 88 79 43 44 44 e82 e44 e55 3 436 661 134 83 86 60 45 43 79 e51 e108 e500 4 278 541 132 82 84 53 46 43 138 e50 e98 e326 5 231 385 122 79 82 51 109 44 e73 e61 e52 e109 6 279 317 120 81 79 51 145 74 e59 e51 e46 94 7 231 442 118 75 82 50 67 678 e52 e44 e45 182 8 325 468 116 75 78 50 54 376 e47 e41 e41 233 9 353 331 113 76 e76 48 49 551 e46 e40 e39 179 10 396 300 114 73 e75 45 48 446 e44 e38 e40 129 11 296 278 112 71 102 45 43 475 e42 e40 e38 e97 12 217 374 115 73 97 45 44 e204 e40 e91 e38 e76 13 272 438 114 75 109 44 45 e140 e40 e274 e37 e70 14 284 288 109 75 e84 45 50 116 e39 e79 e36 e67 15 290 270 130 78 e83 46 45 e114 e39 e122 e36 e63 16 383 236 126 74 82 46 43 e99 e41 e62 e38 e144 17 374 227 147 e76 75 48 41 e78 e116 e51 e37 e78 18 733 198 146 e74 72 46 40 75 139 e49 e45 e79 19 605 194 e114 e73 70 47 43 e95 e98 e52 e53 e74 20 498 181 e105 e73 71 48 45 e59 e72 e46 e46 105 21 427 180 99 e72 69 50 48 e53 e57 e42 e42 256 22 373 191 96 e72 104 56 73 e53 e56 e41 e41 344 23 514 177 96 e72 98 84 80 e49 e54 e44 e52 474 24 568 198 92 e72 91 148 61 e44 e63 e86 e592 253 25 603 176 92 e73 128 98 52 e40 e66 e51 115 e112 26 507 172 93 e71 80 58 167 44 e60 e43 e209 e86 27 359 169 92 e75 66 54 210 e45 e60 e38 e143 e72 28 342 157 89 123 57 51 64 e56 e63 e37 e68 e65 29 315 152 86 195 --- 51 53 49 e128 e38 e79 e61 30 434 150 85 256 --- 46 48 44 e271 e80 77 e58 31 635 --- 84 122 --- 43 --- 43 --- e74 e58 --- TOTAL 12388 9092 3478 2751 2361 1741 1943 4320 2170 2009 2442 4493 MEAN 400 303 112 88.7 84.3 56.2 64.8 139 72.3 64.8 78.8 150 MAX 733 672 152 256 128 148 210 678 271 274 592 500 MIN 217 150 84 71 57 43 40 40 39 37 36 52 AC-FT 24570 18030 6900 5460 4680 3450 3850 8570 4300 3980 4840 8910 CFSM 3.12 2.37 .88 .69 .66 .44 .51 1.09 .57 .51 .62 1.17 IN. 3.60 2.64 1.01 .80 .69 .51 .56 1.26 .63 .58 .71 1.31 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1946 - 2001, BY WATER YEAR (WY) MEAN 424 354 263 194 166 133 245 398 155 103 148 312 MAX 2422 1029 1296 679 1393 477 1174 2293 512 438 1212 1295 (WY) 1971 2000 1966 1952 1950 1969 1969 1985 1999 1979 1979 1996 MIN 91.9 34.7 29.7 26.2 41.6 29.7 28.5 29.6 17.8 14.1 27.0 23.9 (WY) 1994 1995 1995 1995 1957 1994 1984 1994 1994 1994 1994 1994 159 RIO GRANDE DE MANATI BASIN 50035000 RIO GRANDE DE MANATI AT CIALES, PR--Continued SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1946 - 2001 ANNUAL TOTAL 67777 49188 ANNUAL MEAN 185 135 242 HIGHEST ANNUAL MEAN 520 1971 LOWEST ANNUAL MEAN 47.3 1994 HIGHEST DAILY MEAN 898 May 9 733 Oct 18 42700 May 18 1985 LOWEST DAILY MEAN 39 Aug 19 36 Aug 14 8.5 Jul 28 1994 ANNUAL SEVEN-DAY MINIMUM 45 Aug 8 37 Aug 11 9.5 Jul 24 1994 MAXIMUM PEAK FLOW 2920 Nov 1 128000 Sep 10 1996 MAXIMUM PEAK STAGE 6.44 Nov 1 25.20 Sep 10 1996 INSTANTANEOUS LOW FLOW 29 Jul 10 8.5 Jul 27 1994 ANNUAL RUNOFF (AC-FT) 134400 97560 175400 ANNUAL RUNOFF (CFSM) 1.45 1.05 1.89 ANNUAL RUNOFF (INCHES) 19.70 14.30 25.70 10 PERCENT EXCEEDS 431 348 445 50 PERCENT EXCEEDS 120 78 114 90 PERCENT EXCEEDS 52 43 50 e Estimated O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 160 RIO GRANDE DE MANATI BASIN 50035500 RIO GRANDE DE MANATI AT HIGHWAY 149 AT CIALES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°20'46", long 66°28'06", at bridge on Highway 149, about 800 ft (244 m) upstream from confluence with Río Cialitos, 0.5 mi (0.8 km) north of Ciales plaza. DRAINAGE AREA.--136 mi2 (352 km2) this excludes the 6 mi2 (15.5 km2) upstream from Lago El Guineo and Lago de Matrullas, flow from which is diverted to Río Jacaguas. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 12... 1515 172 209 8.2 28.3 7.5 8.0 104 <10 520 210 80 20.4 FEB 20... 1030 76 270 7.8 24.1 2.9 8.2 98 <10 22000 E20 -- -- MAY 01... 1320 59 256 7.5 27.8 7.0 8.4 108 <10 410 E140 97 25.4 AUG 29... 1400 140 210 7.5 28.4 -- 8.8 114 <10 4300 870 84 21.6 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 12... 6.97 9.9 .5 1.51 82 <1.0 7.3 9.6 E.1 25.0 130 60.4 16 FEB 20... -- -- -- -- 105 -- -- -- -- -- -- -- <10 MAY 01... 8.18 11.5 .5 1.60 97 <1.0 9.6 12.5 E.1 25.3 152 24.1 11 AUG 29... 7.29 9.7 .5 1.46 81 -- 9.0 10.6 E.1 22.8 131 49.7 10 NITRO- CHRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) OCT 12... <.01 .3 .06 -- <.20 -- -- .060 <2 38.2 24 <.11 M FEB 20... <.01 .2 .02 -- <.20 -- -- <.020 -- -- -- -- -- MAY 01... <.01 3.4 .20 .41 .61 4.0 17.8 .550 <2 45.3 E16 <.11 <1 AUG 29... <.01 .2 .02 -- <.20 -- -- <.020 -- -- -- -- -- 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- DATE (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) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 12... <20.0 540 <1 39 <.14 <2.6 <.43 <31 <.01 <16 <.02 FEB 20... -- -- -- -- -- -- -- -- -- -- -- MAY 01... <20.0 310 <1 55 <.01 <2.6 <.43 <31 <.01 <16 <.04 AUG 29... -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 161 RIO GRANDE DE MANATI BASIN 50035950 RIO CIALITOS AT HIGHWAY 649 AT CIALES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°20'18", long 66°28'28", 100 ft (30 m) upstream from bridge on Highway 649, 0.7 mi (1.1 km) upstream from mouth, and about 0.4 mi (0.6 km) west of Ciales plaza. DRAINAGE AREA.--17.0 mi2 (44.0 km2). PERIOD OF RECORD.--Water years 1969-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 13... 1430 17 212 7.9 27.6 69 8.2 104 18 4500 800 77 21.5 FEB 20... 1200 9.8 256 7.8 22.4 2.5 8.9 104 <10 200 350 -- -- MAY 02... 1500 7.9 253 7.8 30.4 7.5 7.8 106 <10 E710 E120 100 29.5 AUG 20... 1110 16 212 7.2 27.0 -- 6.0 76 <10 530 4700 100 30.3 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 13... 5.53 9.8 .5 1.71 87 <1.0 5.8 9.6 E.1 26.8 133 6.16 66 FEB 20... -- -- -- -- 103 -- -- -- -- -- -- -- <10 MAY 02... 6.42 11.0 .5 1.61 99 <1.0 8.5 13.5 E.1 25.9 156 3.31 <10 AUG 20... 6.39 10.9 .5 1.91 69 -- 6.8 11.0 E.1 25.9 135 5.73 11 NITRO- CHRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) OCT 13... <.01 .6 .07 .48 .55 1.1 5.1 .240 E1 62.7 E18 <.11 2 FEB 20... <.01 .4 .02 -- <.20 -- -- .040 -- -- -- -- -- MAY 02... <.01 .4 .03 .20 .23 .60 2.7 .070 <2 51.3 E12 <.11 <1 AUG 20... <.01 .5 .03 .29 .32 .79 3.5 .080 -- -- -- -- -- 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- DATE (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) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 13... <20.0 1960 <1 112 <.14 <2.6 <.43 <31 <.01 <16 <.02 FEB 20... -- -- -- -- -- -- -- -- -- -- -- MAY 02... <20.0 160 <1 18 <.01 <2.6 <.43 <31 <.01 <16 -- AUG 20... -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 162 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR LOCATION.--Lat 18°25'52", long 66°31'37", Hydrologic Unit 21010002, at bridge on Highway 2, and 2.3 mi (3.7 km) west of Manatí. DRAINAGE AREA.--197 mi2 (510 km2), approximately, of which about 38 mi2 (98 km2) is partly or entirely noncontributing, excludes 6.0 mi2 (15.5 km2) upstream from Lago El Guineo and Lago de Matrullas. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1963-68 (annual maximum discharge only), February 1970 to current year. REVISED RECORDS.--WRD PR-86-1: 1970-71 (M), 1975, 1979, 1982-85 (P). GAGE.--Water-stage recorder. Elevation of gage is 14 ft (4 m), from topographic map. Prior to 1968 crest-stage gage at same site and datum 3.57 ft (1.09 m) lower. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. Possible water extraction about 500 ft (152.4 m) upstream of gage by unknown source affecting low flow. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate gage heights to gage datum of major floods, pointed out by local residents, are as follows: Sept. 13, 1928, 36.6 ft (11.16 m), Sept. 27, 1932, 36.3 ft (11.06 m), and Aug. 4, 1945, 34.3 ft (10.45 m). DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 205 1340 e231 118 150 133 77 132 82 e209 e79 119 2 364 3400 e189 117 135 156 73 96 88 e153 e85 149 3 268 3330 e180 118 130 157 73 72 81 e100 e145 e322 4 287 e1500 e193 114 122 122 73 68 168 97 e89 e129 5 222 e1020 e168 112 117 111 75 62 107 119 e80 e110 6 196 e796 e163 110 116 105 267 66 90 99 e77 e108 7 185 e1890 e166 109 116 99 159 3690 81 86 e82 e129 8 263 e2060 162 107 117 93 110 442 75 80 e76 e140 9 309 e1350 158 107 114 88 94 852 73 77 e78 e127 10 227 e983 155 106 113 83 87 535 71 75 e84 e114 11 198 e847 152 103 119 77 82 912 68 77 e80 e113 12 217 e1280 154 102 131 73 83 294 66 177 e78 e116 13 218 e1790 159 104 130 73 82 187 66 532 e75 e132 14 211 e949 155 105 126 73 86 154 65 152 e73 e131 15 189 e840 169 113 123 72 85 142 65 237 e83 103 16 192 e642 186 105 127 72 78 126 67 120 e77 167 17 273 e597 206 103 124 71 74 115 114 e98 e96 120 18 346 e433 206 107 120 70 71 110 130 e94 e120 137 19 965 e404 166 100 115 68 69 125 102 101 e85 129 20 1330 e331 151 98 115 71 68 118 84 89 e77 125 21 470 e326 144 96 117 75 85 102 74 82 e74 235 22 363 e390 139 95 198 79 92 96 71 80 e76 547 23 863 e314 138 94 200 97 186 92 69 85 e98 946 24 1690 e431 135 93 161 215 172 89 80 167 353 368 25 794 e298 132 94 210 167 115 e86 84 99 168 220 26 716 e282 133 91 208 115 109 e86 76 86 e140 165 27 370 e266 136 99 172 92 559 e86 77 79 e140 159 28 341 e213 128 143 145 93 159 e85 80 77 125 147 29 308 e205 124 168 --- 92 106 e86 e166 e75 130 134 30 377 e192 122 393 --- 85 90 e85 e357 e156 127 123 31 1240 --- 119 203 --- 79 --- e80 --- e93 112 --- TOTAL 14197 28699 4919 3727 3871 3056 3539 9271 2877 3851 3262 5764 MEAN 458 957 159 120 138 98.6 118 299 95.9 124 105 192 MAX 1690 3400 231 393 210 215 559 3690 357 532 353 946 MIN 185 192 119 91 113 68 68 62 65 75 73 103 AC-FT 28160 56920 9760 7390 7680 6060 7020 18390 5710 7640 6470 11430 CFSM 2.32 4.86 .81 .61 .70 .50 .60 1.52 .49 .63 .53 .98 IN. 2.68 5.42 .93 .70 .73 .58 .67 1.75 .54 .73 .62 1.09 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1970 - 2001, BY WATER YEAR (WY) MEAN 719 592 418 270 208 179 333 629 240 153 211 613 MAX 2958 1835 1717 879 444 521 1037 3178 815 577 1644 3732 (WY) 1971 2000 2000 1997 1988 1972 1993 1985 1999 1979 1979 1998 MIN 154 71.0 55.1 59.1 72.0 56.2 49.9 93.7 63.8 53.0 67.9 67.4 (WY) 1995 1995 1998 1995 1994 1994 1995 1989 1994 1994 1984 1994 163 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR--Continued SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1970 - 2001 ANNUAL TOTAL 117833 87033 ANNUAL MEAN 322 238 379 HIGHEST ANNUAL MEAN 756 1971 LOWEST ANNUAL MEAN 96.5 1994 HIGHEST DAILY MEAN 3400 Nov 2 3690 May 7 80400 Sep 22 1998 LOWEST DAILY MEAN 72 Aug 14 62 May 5 31 Jan 24 1995 ANNUAL SEVEN-DAY MINIMUM 76 Aug 9 67 Jun 10 33 Jul 23 1994 MAXIMUM PEAK FLOW 11000 May 7 198000 Sep 10 1996 MAXIMUM PEAK STAGE 27.89 May 7 36.39 Sep 10 1996 INSTANTANEOUS LOW FLOW 56 May 6 28 Jan 23 1995 ANNUAL RUNOFF (AC-FT) 233700 172600 274700 ANNUAL RUNOFF (CFSM) 1.63 1.21 1.93 ANNUAL RUNOFF (INCHES) 22.25 16.43 26.16 10 PERCENT EXCEEDS 726 415 680 50 PERCENT EXCEEDS 192 119 166 90 PERCENT EXCEEDS 89 75 82 e Estimated O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 164 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 13... 1042 195 260 7.6 28.0 20 6.9 88 <10 3200 2500 110 31.6 FEB 27... 1505 172 289 8.0 25.8 4.5 9.5 117 <10 3700 560 -- -- APR 26... 1035 97 290 7.4 26.3 8.5 7.6 94 -- >6000 1600 120 38.0 AUG 27... 1100 152 259 7.4 28.9 -- 6.7 87 -- E710 380 -- -- ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 13... 6.36 9.8 .4 1.78 106 <1.0 E.1 11.4 E.1 21.1 -- -- 54 FEB 27... -- -- -- -- 117 -- -- -- -- -- -- -- 15 APR 26... 6.34 9.1 .4 2.05 116 <1.0 8.3 12.1 E.1 15.0 161 42.2 13 AUG 27... -- -- -- -- 85 -- -- -- -- -- -- -- -- NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) OCT 13... .65 .02 .7 .12 .20 .32 .99 4.4 .120 <2 48.9 23 <.11 FEB 27... -- <.01 .5 .06 .20 .26 .74 3.3 .070 -- -- -- -- APR 26... -- <.01 .8 .05 .30 .35 1.1 4.9 .100 <2 46.8 21 <.11 AUG 27... -- <.01 .8 .03 .26 .29 1.1 4.8 .090 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 13... 2 <20.0 1220 <1 81 <.14 <2.6 <.43 <31 <.01 <16 <.02 FEB 27... -- -- -- -- -- -- -- -- -- -- -- -- APR 26... <1 <20.0 250 <1 27 <.01 <2.6 <.43 <31 <.01 <16 .05 AUG 27... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value > -- Greater than 165 LAGUNA TORTUGUERO BASIN 50038200 LAGUNA TORTUGUERO OUTLET NEAR VEGA BAJA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°28'29", long 66°26'50", at bridge on Highway 686, 4.2 mi (6.8 km) northeast of Manatí, and 4.4 mi (7.1 km) northwest of Vega Baja plaza. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1964-66, 1969-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 PH OXYGEN, OXYGEN COLI- FECAL ANC RESIDUE SPE- WATER DIS- DEMAND, FORM, STREP, WATER TOTAL NITRO- CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP UNFLTRD AT 105 GEN, CON- FIELD TEMPER- OXYGEN, (PER- ICAL 0.7 MF, FET SULFIDE DEG. C, NITRATE DUCT- (STAND- ATURE DIS- CENT (HIGH UM-MF WATER FIELD TOTAL SUS- TOTAL DATE TIME ANCE ARD WATER SOLVED SATUR- LEVEL) (COLS./ (COL/ MG/L AS (MG/L PENDED (MG/L (US/CM) UNITS) (DEG C) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3 AS S) (MG/L) AS N) (00095) (00400) (00010) (00300) (00301) (00340) (31625) (31673) (00410) (00745) (00530) (00620) OCT 02... 1015 1140 7.4 28.9 5.6 73 31 -- -- 106 <1.0 <10 .30 FEB 06... 1055 1210 7.7 25.8 7.0 86 31 E28 84 112 -- <10 .51 APR 27... 1530 1290 7.6 29.7 6.9 91 35 E40 E46 107 <1.0 <10 -- AUG 29... 1035 1380 7.5 29.8 5.1 68 <10 96 480 104 -- 27 -- NITRO- MANGA- NITRO- NITRO- NITRO- NITRO- GEN,AM- BORON, COPPER, IRON, NESE, ZINC, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS B) AS CU) AS FE) AS MN) AS ZN) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01022) (01042) (01045) (01055) (01092) OCT 02... .01 .3 .44 .86 1.3 1.6 7.1 <.020 71 <20.0 40 3 <31 FEB 06... .01 .5 .24 .64 .88 1.4 6.2 <.020 -- -- -- -- -- APR 27... <.01 .4 .22 1.1 1.3 1.7 7.7 <.020 76 <20.0 20 E2 <31 AUG 29... <.01 .3 .36 1.0 1.4 1.7 7.5 <.020 -- -- -- -- -- METHY- LENE BLUE CYANIDE ACTIVE TOTAL PHENOLS SUB- DATE (MG/L TOTAL STANCE AS CN) (UG/L) (MG/L) (00720) (32730) (38260) OCT 02... E.01 <16 .04 FEB 06... -- -- -- APR 27... <.01 <16 .10 AUG 29... -- -- -- < -- Less than E -- Estimated value 166 THIS PAGE IS INTENTIONALLY BLANK 167 Figure 15. Río Cibuco basin. 168 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR LOCATION.--Lat l8°21'13", long 66°20'07", Hydrologic Unit 21010001, on right bank, 150 ft (46 m) downstream from junction with Río Corozal, and 1.4 mi (2.3 km) northwest of Corozal. DRAINAGE AREA.--15.1 mi2 (39.1 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--May 1969 to current year. GAGE.--Water-stage recorder. Elevation of gage is 195 ft (59 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. Daily discharge affected by sewage treatment plant about 0.6 mi (1.0 km) upstream from station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 37 145 13 7.6 9.1 18 5.2 6.1 6.0 7.3 e9.8 e7.2 2 18 52 12 7.6 8.7 13 5.1 6.0 6.2 6.1 e13 e7.9 3 14 194 11 8.1 8.3 8.7 5.2 5.2 5.7 5.2 e8.8 e7.9 4 12 30 11 7.5 7.2 8.0 5.4 5.3 11 7.0 e7.8 e8.0 5 11 20 e11 7.1 7.6 7.9 5.7 5.1 7.2 8.6 e7.3 e8.3 6 11 15 e11 7.1 7.5 7.8 6.3 68 5.7 5.0 e8.7 e6.8 7 11 83 e11 7.5 8.0 7.7 5.9 160 5.5 4.6 e15 e6.5 8 13 28 e10 7.1 7.9 7.4 5.3 84 5.5 4.0 e8.4 e6.5 9 11 24 e11 6.7 8.2 7.1 5.8 31 5.4 e4.0 e7.8 e6.4 10 11 21 e10 6.6 8.2 6.8 5.3 13 e5.3 e4.5 e8.0 e6.5 11 11 19 e9.3 6.5 13 6.6 6.1 11 e5.0 e4.0 e9.5 e6.3 12 9.5 18 e10 6.7 10 6.5 5.5 7.5 5.2 e5.0 e9.7 e6.5 13 9.0 16 e9.4 7.4 9.3 8.7 5.9 6.6 5.3 e4.1 e7.4 e9.1 14 9.7 21 e17 9.3 9.1 7.1 5.5 6.4 e4.9 e4.0 e6.9 e11 15 19 35 15 9.4 12 6.4 4.8 6.3 e4.3 e3.9 e7.2 e7.1 16 12 18 25 8.1 10 6.3 5.2 5.9 9.1 e4.2 e9.8 e7.8 17 9.4 16 24 8.5 9.8 6.1 4.9 5.5 12 e4.1 e7.1 e6.6 18 8.8 16 15 9.1 8.7 6.1 4.4 6.8 7.7 e4.0 e12 e15 19 16 15 11 7.4 9.1 6.3 4.4 9.3 6.1 e5.8 e7.8 e20 20 13 18 10 7.3 9.6 8.4 4.5 6.7 5.6 e4.8 e7.5 e7.7 21 11 19 9.8 7.2 11 7.5 10 6.5 5.0 e4.5 e6.8 e7.2 22 38 27 9.3 7.6 22 11 15 6.1 4.9 e10 e6.7 27 23 221 18 9.0 8.0 11 8.2 62 6.0 4.7 e15 e25 12 24 35 16 8.5 7.1 13 6.4 16 6.0 6.2 e7.6 e13 7.8 25 14 15 8.4 6.9 15 6.1 9.5 5.6 5.9 e7.4 e9.0 7.2 26 11 16 8.3 6.5 12 5.7 7.6 6.0 e5.8 e10 e7.7 16 27 9.5 15 8.2 11 9.0 5.8 e6.7 5.4 e8.7 e13 e7.5 9.4 28 11 14 8.1 21 8.5 5.5 e6.5 5.7 e7.7 e7.2 e8.7 7.5 29 12 13 7.8 33 --- 5.3 6.1 5.2 7.0 e15 e8.4 6.8 30 141 14 8.0 19 --- 5.4 5.6 5.8 7.5 e30 e7.8 6.5 31 37 --- 7.5 11 --- 5.4 --- 5.4 --- e11 e7.2 --- TOTAL 806.9 971 349.6 290.9 282.8 233.2 251.4 519.4 192.1 230.9 287.3 276.5 MEAN 26.0 32.4 11.3 9.38 10.1 7.52 8.38 16.8 6.40 7.45 9.27 9.22 MAX 221 194 25 33 22 18 62 160 12 30 25 27 MIN 8.8 13 7.5 6.5 7.2 5.3 4.4 5.1 4.3 3.9 6.7 6.3 AC-FT 1600 1930 693 577 561 463 499 1030 381 458 570 548 CFSM 1.72 2.14 .75 .62 .67 .50 .55 1.11 .42 .49 .61 .61 IN. 1.99 2.39 .86 .72 .70 .57 .62 1.28 .47 .57 .71 .68 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2001, BY WATER YEAR (WY) MEAN 42.0 49.3 39.7 25.1 21.3 20.3 30.2 41.8 14.9 12.2 16.1 33.0 MAX 135 155 169 69.6 51.3 65.1 111 157 44.4 35.6 50.8 191 (WY) 1991 1971 1971 1992 1988 1981 1973 1986 1987 1999 1979 1996 MIN 8.05 5.63 1.94 6.93 7.75 4.36 3.32 3.20 1.63 2.19 3.44 3.88 (WY) 1979 1998 1998 1995 1994 1984 1984 1977 1994 1994 1978 1994 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1969 - 2001 ANNUAL TOTAL 7483.7 4692.0 ANNUAL MEAN 20.4 12.9 28.9 HIGHEST ANNUAL MEAN 56.5 1971 LOWEST ANNUAL MEAN 7.47 1994 HIGHEST DAILY MEAN 237 May 11 221 Oct 23 3070 Sep 10 1996 LOWEST DAILY MEAN 4.3 Jul 26 3.9 Jul 15 .91 Jul 17 1994 ANNUAL SEVEN-DAY MINIMUM 4.4 Jul 24 4.2 Jul 11 1.2 Jun 21 1994 MAXIMUM PEAK FLOW 4340 Oct 23 20400 Nov 9 1995 MAXIMUM PEAK STAGE 13.17 Oct 23 22.35 Nov 9 1995 ANNUAL RUNOFF (AC-FT) 14840 9310 20950 ANNUAL RUNOFF (CFSM) 1.35 .85 1.92 ANNUAL RUNOFF (INCHES) 18.44 11.56 26.03 10 PERCENT EXCEEDS 36 18 51 50 PERCENT EXCEEDS 13 8.0 13 90 PERCENT EXCEEDS 5.9 5.3 5.1 e Estimated 169 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR--Continued O N D 2000 J F M A M J J A S 2001 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 170 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1969-76, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 03... 0950 15 378 7.6 25.0 14 8.0 97 11 2600 560 140 35.2 FEB 07... 0915 8.3 401 7.7 22.0 4.9 7.9 91 <10 E1000 450 -- -- APR 30... 0950 6.2 432 7.7 24.7 3.3 7.9 95 <10 E850 350 160 42.9 SEP 07... 0915 5.3 467 7.5 26.5 -- 6.4 80 10 39000 580 180 47.2 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 03... 12.2 18.2 .7 3.21 123 <1.0 16.4 25.0 <.1 30.8 215 8.46 <10 FEB 07... -- -- -- -- 139 -- -- -- -- -- -- -- <10 APR 30... 13.6 20.2 .7 3.30 151 <1.0 15.8 29.1 E.1 30.9 246 4.12 <10 SEP 07... 14.0 25.6 .8 3.94 152 -- 16.6 38.6 E.1 29.5 266 3.80 <10 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) OCT 03... -- <.01 2.5 .05 .20 .25 2.8 12.2 .260 <2 51.6 29 <.11 FEB 07... 2.09 .01 2.1 .02 .29 .31 2.4 10.7 .260 -- -- -- -- APR 30... 1.79 .01 1.8 .02 .24 .26 2.1 9.1 .340 <2 51.0 42 <.11 SEP 07... 4.56 .14 4.7 .12 .33 .45 5.2 22.8 .690 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 03... M <20.0 300 <1 39 <.14 <2.6 <.43 E17 <.01 <16 .19 FEB 07... -- -- -- -- -- -- -- -- -- -- -- -- APR 30... <1 <20.0 110 <1 35 <.01 <2.6 <.43 <31 <.01 <16 <.04 SEP 07... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than M -- Presence verified, not quantified E -- Estimated value 171 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR LOCATION.--Lat 18°26'53", long 66°22'29", Hydrologic Unit 21010002, on left bank, at bridge on Hwy 2, 0.6 mi (1.0 km) downstream from Río Indio, and 0.8 mi (1.3 km) east of Vega Baja. DRAINAGE AREA.--99.1 mi2 (256.7 km2), of which 25.4 mi2 (65.8 km2), does not contribute directly to surface runoff. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1973 to current year. GAGE.--Water-stage recorder. Datum of gage is 7.79 ft (2.374 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 ft3/s (793 m3/s). DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 84 293 46 33 52 59 29 26 18 31 46 22 2 137 420 41 32 46 143 27 26 28 28 84 29 3 56 1080 39 35 42 132 26 23 22 24 34 28 4 41 277 37 35 36 70 28 22 19 44 27 30 5 32 152 37 33 30 59 33 22 40 64 22 32 6 30 102 37 32 28 53 34 26 22 31 39 19 7 29 190 35 32 27 50 36 599 18 24 120 18 8 44 207 36 31 26 48 33 148 17 23 31 17 9 41 92 37 29 26 46 35 283 17 22 27 16 10 36 73 37 28 29 43 34 90 17 23 28 16 11 60 61 38 27 55 39 35 77 16 34 41 16 12 30 54 41 27 52 37 35 50 15 23 45 17 13 27 51 56 29 43 38 35 38 16 22 24 42 14 26 50 54 29 34 58 34 36 15 22 20 61 15 47 180 68 37 52 40 32 40 15 20 21 22 16 147 143 80 30 56 39 28 31 43 19 49 28 17 41 64 222 33 46 38 29 28 102 19 21 19 18 42 56 117 33 38 36 28 27 44 18 81 115 19 110 51 78 30 33 34 27 46 26 37 29 177 20 206 48 63 28 35 36 25 30 21 24 26 52 21 67 56 54 29 37 49 54 24 18 20 19 57 22 110 102 49 28 353 46 78 23 17 73 19 29 23 462 84 49 30 110 70 139 23 17 130 249 90 24 565 53 46 29 97 41 193 22 18 40 95 30 25 169 49 43 27 122 38 75 22 18 37 38 24 26 89 50 40 26 100 33 45 20 21 69 27 23 27 61 53 39 34 84 32 36 20 18 107 26 108 28 65 47 38 98 66 31 34 20 e46 35 36 35 29 69 44 36 135 --- 31 31 20 27 123 33 30 30 196 43 32 243 --- 32 26 17 35 322 28 23 31 383 --- 34 76 --- 30 --- 18 --- 60 23 --- TOTAL 3502 4225 1659 1378 1755 1531 1334 1897 766 1568 1408 1225 MEAN 113 141 53.5 44.5 62.7 49.4 44.5 61.2 25.5 50.6 45.4 40.8 MAX 565 1080 222 243 353 143 193 599 102 322 249 177 MIN 26 43 32 26 26 30 25 17 15 18 19 16 AC-FT 6950 8380 3290 2730 3480 3040 2650 3760 1520 3110 2790 2430 CFSM 1.14 1.42 .54 .45 .63 .50 .45 .62 .26 .51 .46 .41 IN. 1.31 1.59 .62 .52 .66 .57 .50 .71 .29 .59 .53 .46 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1973 - 2001, BY WATER YEAR (WY) MEAN 160 204 202 106 88.5 78.9 137 176 71.2 56.7 77.0 142 MAX 559 523 1316 339 190 339 667 655 239 235 461 690 (WY) 1986 1980 1982 1997 1988 1990 1987 1985 1987 1999 1979 1996 MIN 45.9 28.3 12.9 30.2 27.2 20.5 16.2 24.7 12.5 14.0 21.2 26.7 (WY) 1974 1998 1998 1995 1994 1994 1984 1977 1994 1994 1978 1994 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1973 - 2001 ANNUAL TOTAL 34628 22248 ANNUAL MEAN 94.6 61.0 124 HIGHEST ANNUAL MEAN 236 1982 LOWEST ANNUAL MEAN 38.5 1994 HIGHEST DAILY MEAN 1080 Nov 3 1080 Nov 3 14600 Dec 13 1981 LOWEST DAILY MEAN 21 Aug 18 15 Jun 12 7.2 May 3 1995 ANNUAL SEVEN-DAY MINIMUM 23 Aug 16 16 Jun 9 8.1 Apr 28 1995 MAXIMUM PEAK FLOW 2140 Oct 23 34000 Apr 12 1987 MAXIMUM PEAK STAGE 12.31 Oct 23 19.10 Apr 12 1987 INSTANTANEOUS LOW FLOW 13 Jun 14 7.2 May 2 1995 ANNUAL RUNOFF (AC-FT) 68680 44130 89640 ANNUAL RUNOFF (CFSM) .95 .62 1.25 ANNUAL RUNOFF (INCHES) 13.00 8.35 16.97 10 PERCENT EXCEEDS 205 116 235 50 PERCENT EXCEEDS 52 36 57 90 PERCENT EXCEEDS 28 20 22 e Estimated 172 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR--Continued O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 173 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 02... 1430 87 328 7.4 25.8 240 6.8 84 10 21000 E12000 140 43.0 FEB 06... 0835 30 477 7.8 23.8 3.0 6.7 80 <10 420 420 -- -- APR 30... 1220 23 488 7.6 26.4 3.5 6.5 81 <10 290 270 200 63.9 AUG 14... 1220 34 460 7.0 29.3 -- 5.4 71 -- 360 250 190 61.5 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 02... 7.14 11.2 .4 3.24 121 <1.0 12.7 15.6 <.1 17.1 182 43.0 188 FEB 06... -- -- -- -- 182 -- -- -- -- -- -- -- <10 APR 30... 10.0 18.3 .6 3.09 189 <1.0 15.0 28.9 E.1 18.6 271 16.6 <10 AUG 14... 9.42 17.3 .5 3.19 184 -- 15.2 27.8 E.1 18.1 263 24.2 -- NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) OCT 02... 1.17 .03 1.2 .07 .54 .61 1.8 8.0 .310 E2 67.4 26 <.11 FEB 06... 1.79 .01 1.8 .02 .52 .54 2.3 10.4 .140 -- -- -- -- APR 30... 1.38 .02 1.4 <.01 -- .21 1.6 7.1 .160 <2 48.5 43 <.11 AUG 14... .95 .02 1.0 .04 .27 .31 1.3 5.7 .130 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 02... 14 E16.9 5590 2 162 <.14 <2.6 <.43 E19 <.01 <16 <.02 FEB 06... -- -- -- -- -- -- -- -- -- -- -- -- APR 30... <1 <20.0 100 <1 23 <.01 <2.6 <.43 <31 <.01 <16 .06 AUG 14... -- -- -- -- -- -- -- -- -- -- -- -- E -- Estimated value < -- Less than 174 THIS PAGE IS INTENTIONALLY BLANK 175 Figure 16. Río de la Plata basin. 176 RIO DE LA PLATA BASIN 50039990 LAGO CARITE AT GATE TOWER NEAR CAYEY, PR LOCATION.--Lat 18°03'46", long 66°05'58", Hydrologic Unit 21010005, on top of a concrete tower at diversion tunnel on Carite Reservoir, 0.7 mi (1.1 km) northwest from Escuela Carite Chino, 1.2 mi (1.9 km) northeast from Central Hidroelectrica de Carite Num. 1 and 1.8 mi (2.9 km) northeast from Escuela Segunda Unidad. DRAINAGE AREA.--8.20 mi2 (21.24 km2). ELEVATION RECORDS PERIOD OF RECORD.--May 1989 to current year. Prior to October 1994, published as Lago Carite at Gate Tower. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Carite Dam was completed in 1913. The operation of the reservoir is controlled by the utilization of water to meet the demands for domestic, industrial and agricultural purposes in the Guayama Area. The dam is an earthfill with crest elevation of 1,806 ft (550 m) above mean sea level, with a structural height of 104 ft (32 m) and a lenght of 500 ft (152 m). The dam has a capacity of approximately 11,310 acre-feet (13.9 hm3). The Dam is operated by the Puerto Rico Electric and Power Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 1,789.62 ft (545.48 m), Sep. 21, 1998; minimum elevation,1,761.22 ft (536.81 m), May 28, 1995. EXTREMES FOR CURRENT YEAR.--Maximum elevation 1,778.55 ft (542.10 m), Oct. 11,12; minimum elevation, 1,763.58 ft (537.54 m), Aug.22. Capacity Table (based on Data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 1,746 0 1,775 6,194 1,760 2,471 1,780 7,704 1,769 4,561 1,790 11,048 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1776.63 1778.15 1777.49 1777.55 1775.81 1773.94 1771.81 1769.55 1769.95 1767.21 1765.26 1769.41 2 1777.54 1778.20 1777.47 1777.49 1775.81 1773.85 1771.68 1769.51 1769.90 1767.23 1765.16 1769.63 3 1777.79 1778.16 1777.40 1777.43 1775.78 1773.75 1771.61 1769.35 1769.80 1767.16 1765.06 1769.74 4 1777.84 1778.08 1777.34 1777.37 1775.71 1773.66 1771.51 1769.27 1769.70 1767.17 1764.95 1769.87 5 1777.90 1778.03 1777.31 1777.32 1775.65 1773.57 1771.40 1769.18 1769.64 1767.17 1764.86 1769.88 6 1777.92 1777.97 1777.25 1777.27 1775.60 1773.48 1771.31 1769.36 1769.55 1767.09 1764.77 1769.86 7 1777.92 1778.02 1777.19 1777.23 1775.52 1773.38 1771.24 1770.81 1769.45 1766.98 1764.68 1769.83 8 1778.42 1777.98 1777.15 1777.15 1775.46 1773.26 1771.11 1771.22 1769.35 1766.88 1764.56 1769.77 9 1778.51 1777.92 1777.11 1777.11 1775.37 1773.17 1771.02 1771.28 1769.26 1766.77 1764.46 1769.72 10 1778.53 1777.85 1777.06 1777.03 1775.29 1773.06 1770.94 1771.23 1769.23 1766.68 1764.35 1769.68 11 1778.53 1777.80 1777.01 1776.97 1775.28 1772.96 1770.89 1771.20 1769.05 1766.57 1764.26 1769.64 12 1778.53 1777.73 1776.96 1776.92 1775.22 1772.87 1770.80 1771.17 1768.96 1766.52 1764.22 1769.59 13 1778.52 1777.68 1776.90 1776.84 1775.17 1772.77 1770.70 1771.12 1768.85 1766.43 1764.10 1769.52 14 1778.50 1777.62 1776.87 1776.76 1775.09 1772.66 1770.63 1771.06 1768.77 1766.32 1763.99 1769.50 15 1778.47 1777.54 1776.87 1776.70 1775.02 1772.57 1770.53 1771.00 1768.67 1766.20 1763.92 1769.48 16 1778.52 1777.47 1776.79 1776.66 1774.98 1772.48 1770.43 1770.95 1768.57 1766.08 1763.82 1769.42 17 1778.50 1777.42 1776.76 1776.63 1774.92 1772.38 1770.34 1770.87 1768.53 1765.96 1763.87 1769.38 18 1778.47 1777.37 1776.94 1776.56 1774.85 1772.28 1770.23 1770.84 1768.42 1765.83 1763.85 1769.36 19 1778.48 1777.29 1777.01 1776.51 1774.77 1772.16 1770.15 1770.79 1768.33 1765.73 1763.80 1769.30 20 1778.44 1777.23 1777.15 1776.46 1774.68 1772.12 1770.06 1770.72 1768.22 1765.61 1763.72 1769.25 21 1778.39 1777.21 1777.30 1776.39 1774.60 1772.34 1770.06 1770.64 1768.11 1765.48 1763.63 1769.18 22 1778.37 1777.26 1777.59 1776.31 1774.52 1772.66 1770.04 1770.60 1767.98 1765.35 1765.84 1769.12 23 1778.38 1777.23 1777.74 1776.27 1774.46 1772.77 1769.98 1770.53 1767.88 1765.30 1767.21 1769.04 24 1778.36 1777.24 1777.77 1776.22 1774.41 1772.75 1769.97 1770.48 1767.77 1765.27 1767.20 1768.96 25 1778.35 1777.26 1777.77 1776.15 1774.31 1772.63 1769.93 1770.41 1767.69 1765.43 1767.15 1768.89 26 1778.33 1777.23 1777.76 1776.07 1774.22 1772.53 1769.87 1770.33 1767.59 1765.42 1767.09 1768.87 27 1778.28 1777.27 1777.73 1775.98 1774.12 1772.35 A 1770.24 1767.48 1765.36 1767.00 1768.78 28 1778.30 1777.24 1777.69 1775.91 1774.01 1772.21 1769.72 1770.25 1767.35 1765.24 1768.27 1768.70 29 1778.25 1777.18 1777.66 1776.01 --- 1772.14 1769.63 1770.18 1767.26 1765.36 1768.34 1768.66 30 1778.21 1777.46 1777.64 1775.94 --- 1772.04 1769.55 1770.08 1767.21 1765.42 1768.37 1768.58 31 1778.17 --- 1777.60 1775.86 --- 1771.92 --- 1770.03 --- 1765.35 1768.33 --- MAX 1778.53 1778.20 1777.77 1777.55 1775.81 1773.94 --- 1771.28 1769.95 1767.23 1768.37 1769.88 MIN 1776.63 1777.18 1776.76 1775.86 1774.01 1771.92 --- 1769.18 1767.21 1765.24 1763.63 1768.58 A No gage-height record 177 RIO DE LA PLATA BASIN 50039990 LAGO CARITE AT GATE TOWER NEAR CAYEY, PR--Continued O N D 2000 J F M A M J J A S 2001 1762 1764 1766 1768 1770 1772 1774 1776 1778 1780 ELEVATION, IN FEET Gap indicates missing record 178 RIO DE LA PLATA BASIN 50043000 RIO DE LA PLATA AT PROYECTO LA PLATA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°09'37", long 66°13'44", Hydrologic Unit 21010005, at upstream side of bridge on Highway 173, 0.4 mi (0.6 km) northeast of Proyecto La Plata, and 2.5 mi (4.0 km) upstream from Río Usabón. DRAINAGE AREA.--63.0 mi2 (163.2 km2), excludes 8.2 mi2 (21.1 km2) upstream from Lago Carite, the flow of which is diverted to Río Guamaní. PERIOD OF RECORD.--Water years 1958 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 06... 0955 72 322 7.8 26.5 17 7.8 100 11 E910 E180 110 27.8 FEB 08... 1005 16 477 7.9 23.5 3.6 8.0 97 <10 E710 E73 -- -- MAY 03... 1530 16 434 8.3 29.3 5.4 10.6 143 -- 430 E200 140 33.9 AUG 31... 1140 54 288 7.2 28.4 -- 7.3 97 <10 420 330 93 23.0 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 06... 10.0 21.8 .9 2.07 113 <1.0 12.8 22.2 E.1 23.9 188 36.8 <10 FEB 08... -- -- -- -- 160 -- -- -- -- -- -- -- <10 MAY 03... 13.7 37.5 1 3.19 274 <1.0 16.3 42.3 E.1 22.5 334 14.0 <10 AUG 31... 8.74 20.7 .9 2.47 92 -- 12.0 23.5 E.1 19.4 165 23.8 16 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) OCT 06... 1.18 .02 1.2 .04 .21 .25 1.4 6.4 .100 <2 19.9 41 <.11 FEB 08... 2.57 .03 2.6 .06 .63 .69 3.3 14.6 .100 -- -- -- -- MAY 03... 2.17 .03 2.2 .04 .60 .64 2.8 12.6 .170 <2 22.2 84 <.11 AUG 31... 1.28 .02 1.3 .05 .68 .73 2.0 9.0 .090 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 06... M <20.0 430 <1 19 <.14 <2.6 <.43 <31 <.01 <16 <.02 FEB 08... -- -- -- -- -- -- -- -- -- -- -- -- MAY 03... <1 <20.0 170 <1 18 <.01 <2.6 <.43 <31 <.01 <16 .05 AUG 31... -- -- -- -- -- -- -- -- -- -- -- -- E -- Estimated value < -- Less than M -- Presence verified, not quantified 179 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR LOCATION.--Lat 18°13'23", long 66°13'30", Hydrologic Unit 21010005, on right bank 50 ft (15 m) upstream from bridge off Highway 167 in the Town of Comerío, 0.4 mi (0.6 km) southwest of Comerío High School, and 0.2 mi (0.3 km) northeast of Plaza de Comerío. DRAINAGE AREA.--109 mi2 (282 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 604.2 ft (184.160 m) above mean sea level. REMARKS.--Records fair except those for estimated daily discharges, which are poo. Filtration plant more or less 500 feet upstream from station. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 379 2300 317 44 39 67 23 e22 27 71 54 59 2 1120 3420 111 42 33 129 23 e21 29 57 30 362 3 1010 1000 69 44 36 56 25 e21 25 45 24 166 4 311 334 56 40 32 46 26 e21 22 40 23 106 5 173 180 52 40 27 42 26 e20 27 75 22 81 6 121 135 49 40 25 42 208 e162 40 76 31 56 7 98 301 50 36 24 39 63 e207 26 34 38 44 8 121 391 53 35 24 36 34 e98 24 22 30 39 9 282 150 55 37 25 29 45 e58 22 17 35 36 10 116 109 56 36 31 26 29 e38 19 16 34 32 11 88 93 55 36 32 24 e25 e33 17 16 25 32 12 75 84 55 34 43 27 e23 e31 18 16 20 41 13 90 102 57 34 54 30 e23 e28 18 18 17 38 14 61 83 61 33 36 25 e23 e28 18 21 18 30 15 62 79 90 31 32 24 e22 e27 18 17 19 73 16 72 76 86 33 31 29 e22 e27 19 16 17 119 17 136 71 81 39 32 31 e22 e26 25 14 28 29 18 210 66 85 42 27 24 e20 e28 70 17 60 25 19 414 66 155 34 23 21 e20 e28 33 23 60 34 20 301 63 126 32 24 23 e21 e25 23 17 28 30 21 126 66 137 32 24 41 e56 e25 20 14 19 67 22 335 84 223 30 73 81 e68 e25 18 12 35 110 23 573 99 458 31 53 162 e71 e22 19 12 2790 218 24 450 76 146 31 90 328 e33 e23 21 13 356 56 25 140 69 96 28 118 101 e24 e22 23 18 129 38 26 123 94 84 27 59 54 e23 e22 28 44 67 31 27 88 82 77 26 44 e46 e21 e22 31 32 47 29 28 70 78 83 32 40 e39 e22 23 27 25 799 28 29 96 66 58 97 --- e34 e21 48 26 53 470 26 30 114 74 52 370 --- 29 e21 39 23 209 148 27 31 329 --- 49 53 --- 27 --- 29 --- 128 85 --- TOTAL 7684 9891 3182 1499 1131 1712 1083 1249 756 1188 5558 2062 MEAN 248 330 103 48.4 40.4 55.2 36.1 40.3 25.2 38.3 179 68.7 MAX 1120 3420 458 370 118 328 208 207 70 209 2790 362 MIN 61 63 49 26 23 21 20 20 17 12 17 25 MED 126 84 77 35 32 36 23 27 23 21 34 38 AC-FT 15240 19620 6310 2970 2240 3400 2150 2480 1500 2360 11020 4090 CFSM 2.28 3.04 .95 .45 .37 .51 .33 .37 .23 .35 1.65 .63 IN. 2.63 3.39 1.09 .51 .39 .59 .37 .43 .26 .41 1.91 .71 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 2001, BY WATER YEAR (WY) MEAN 229 227 115 137 92.5 45.3 50.8 83.5 68.7 83.0 136 415 MAX 866 1264 457 732 268 75.7 162 263 213 291 563 1433 (WY) 1991 2000 1999 1992 1998 1989 1993 1992 1996 1993 2000 1996 MIN 40.6 19.0 17.1 21.3 24.4 20.6 22.3 19.7 13.2 10.4 12.7 26.2 (WY) 1992 1995 1995 1995 1990 1993 1991 1994 1994 1994 1994 1997 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1989 - 2001 ANNUAL TOTAL 64220 36995 ANNUAL MEAN 175 101 139 HIGHEST ANNUAL MEAN 267 2000 LOWEST ANNUAL MEAN 35.3 1994 HIGHEST DAILY MEAN 14000 Aug 23 3420 Nov 2 32400 Sep 10 1996 LOWEST DAILY MEAN 17 Aug 21 12 Jul 22 5.8 Jun 25 1994 ANNUAL SEVEN-DAY MINIMUM 20 Aug 15 15 Jul 18 7.3 Jul 31 1994 MAXIMUM PEAK FLOW 17100 Nov 2 127000 Jan 5 1992 MAXIMUM PEAK STAGE 13.56 Nov 2 29.22 Jan 5 1992 ANNUAL RUNOFF (AC-FT) 127400 73380 100500 ANNUAL RUNOFF (CFSM) 1.62 .93 1.28 ANNUAL RUNOFF (INCHES) 22.02 12.68 17.38 10 PERCENT EXCEEDS 301 162 194 50 PERCENT EXCEEDS 64 38 40 90 PERCENT EXCEEDS 28 21 16 e Estimated 180 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR--Continued O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 181 RIO DE LA PLATA BASIN 50044000 RIO DE LA PLATA NEAR COMERIO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°14'33", long 66°12'28", at bridge on Highway 156, 0.56 mi (0.9 km) upstream from dam, about 2.0 mi (3.2 km) northeast of Comerío plaza. DRAINAGE AREA.--139 mi2 (360 km2), excludes 8.2 mi2 (21.1 km2) upstream from Lago Carite, the flow of which is diverted to Río Guamaní. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 11... 1035 109 345 7.5 26.9 7.8 8.6 110 <10 E660 360 120 28.7 FEB 12... 1515 83 425 8.3 25.1 1.9 8.8 109 <10 5000 890 -- -- MAY 03... 1130 39 411 8.1 27.4 5.5 9.4 122 <10 E45 250 140 31.5 AUG 30... 1200 111 257 7.2 28.1 -- 7.3 96 18 2800 350 85 20.7 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 11... 12.8 17.9 .7 2.60 121 <1.0 11.7 20.9 E.1 26.4 194 56.9 <10 FEB 12... -- -- -- -- 146 -- -- -- -- -- -- -- <10 MAY 03... 13.9 30.6 1 3.08 143 <1.0 16.4 36.9 E.1 24.5 242 25.8 <10 AUG 30... 8.10 16.5 .8 2.82 82 -- 11.2 18.3 E.1 18.6 145 43.4 <10 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) OCT 11... -- <.01 .8 .02 -- <.20 -- -- .110 E1 29.4 47 <.11 FEB 12... 1.29 .01 1.3 .03 .18 .21 1.5 6.7 .100 -- -- -- -- MAY 03... -- <.01 .3 .02 .34 .36 .69 3.1 .090 E1 35.3 73 <.11 AUG 30... .85 .02 .9 .06 .24 .30 1.2 5.2 .120 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 11... 2 <20.0 390 <1 17 <.14 <2.6 <.43 <31 <.01 <16 .04 FEB 12... -- -- -- -- -- -- -- -- -- -- -- -- MAY 03... <1 <20.0 120 <1 14 <.01 <2.6 <.43 <31 <.01 <16 .03 AUG 30... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 182 RIO DE LA PLATA BASIN 50044810 RIO GUADIANA NEAR GUADIANA, PR LOCATION.--Lat 18°13'42", long 66°18'05", Hydrologic Unit 21010005, at right bank 1.10 mi (2.1 km)east of Plaza de Naranjito, 0.9 mi (1.4 km) west from intersection of roads 167 and 164 at km 1.77 and 2.6 mi (4.16 km) northwest from Represa Comerio. DRAINAGE AREA.--8.60 mi2 (22.27 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March to September 2001. GAGE.--Water-stage recorder and crest-stage gage. elevation of gage is 229 ft (69.8 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 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 4.7 4.5 5.9 4.0 5.4 3.5 2 4.7 3.8 4.2 3.8 3.4 3.3 3 5.0 3.7 3.8 3.5 3.0 4.0 4 5.5 3.8 6.3 9.7 2.8 3.4 5 7.0 3.6 4.3 4.7 2.4 3.2 6 10 61 3.9 3.5 5.6 3.2 7 5.3 79 3.7 3.1 3.5 3.1 8 4.6 35 3.6 3.0 2.6 2.7 9 5.0 19 3.6 2.9 3.2 2.7 10 4.7 11 3.3 3.6 4.5 2.5 11 5.6 8.8 3.2 3.3 6.3 2.5 12 e4.3 4.6 7.8 3.1 3.5 4.0 2.7 13 4.3 4.8 6.9 3.2 3.8 2.8 2.4 14 4.6 4.9 6.6 3.0 3.1 2.5 2.4 15 4.2 4.4 6.2 3.7 2.9 2.5 2.3 16 4.7 4.5 6.1 3.7 2.8 2.5 2.4 17 5.0 4.1 5.9 7.1 2.3 30 2.3 18 4.9 3.7 6.7 4.2 2.9 6.9 3.9 19 4.9 3.7 e6.9 3.8 2.9 4.9 3.1 20 6.1 3.7 e5.4 3.7 2.3 4.2 2.5 21 5.7 18 e5.4 3.4 2.2 3.8 2.3 22 7.4 23 e5.5 2.9 7.1 5.1 2.1 23 5.4 24 e4.5 4.6 3.3 42 2.2 24 5.4 8.6 e4.7 4.0 3.6 6.5 2.0 25 4.8 5.3 e4.5 4.1 2.5 4.7 1.7 26 4.9 4.6 4.3 3.7 3.5 4.0 2.2 27 4.9 e4.1 4.2 7.6 2.7 4.4 2.7 28 4.5 e4.4 4.2 4.0 2.4 4.6 2.2 29 4.8 4.0 3.8 3.5 16 4.2 2.0 30 4.7 4.0 3.7 8.0 6.0 4.4 1.9 31 4.7 --- 3.8 --- 3.8 4.1 --- TOTAL --- 200.5 340.3 127.1 124.7 190.8 79.4 MEAN --- 6.68 11.0 4.24 4.02 6.15 2.65 MAX --- 24 79 8.0 16 42 4.0 MIN --- 3.7 3.6 2.9 2.2 2.4 1.7 AC-FT --- 398 675 252 247 378 157 CFSM --- .83 1.36 .53 .50 .76 .33 IN. --- .93 1.57 .59 .58 .88 .37 e Estimated 183 RIO DE LA PLATA BASIN 50044810 RIO GUADIANA NR GUADIANA, PR--Continued O N D 2000 J F M A M J J A S 2001 1 2 5 10 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND Gap indicates missing record 184 RIO DE LA PLATA BASIN 50044850 RIO GUADIANA NEAR NARANJITO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°18'39", long 66°13'28", at steel-cross-bridge 0.8 mi (1.3 km) northwest of Highway 164, 1.2 mi (1.9 km) upstream from mouth and about 2.0 mi (3.2 km) northeast of Naranjito plaza. DRAINAGE AREA.--4.0 mi2 (10.3 km2). PERIOD OF RECORD.--Water year 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 11... 0730 8.6 354 7.8 23.9 28 7.0 83 <10 E8000 7100 140 31.3 FEB 12... 1245 6.9 363 8.0 24.8 .6 7.7 93 <10 2800 400 -- -- MAY 02... 1005 4.9 405 7.8 27.2 3.1 8.3 106 <10 380 370 150 36.2 AUG 30... 1405 4.3 411 7.7 29.5 -- 6.8 90 22 590 830 170 39.9 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 11... 14.5 15.9 .6 2.32 123 <1.0 19.9 21.1 E.1 25.0 204 4.74 24 FEB 12... -- -- -- -- 126 -- -- -- -- -- -- -- <10 MAY 02... 15.3 18.3 .6 2.28 142 <1.0 19.1 27.9 E.1 26.6 231 3.03 <10 AUG 30... 16.8 21.8 .7 2.55 146 -- 24.7 30.1 E.2 27.3 251 2.92 <10 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) OCT 11... -- <.01 1.3 .02 -- <.20 -- -- .170 E2 59.6 34 <.11 FEB 12... -- <.01 1.1 .02 .32 .34 1.4 6.4 .180 -- -- -- -- MAY 02... .83 .01 .8 .01 .19 .20 1.0 4.6 .220 E2 55.9 34 <.11 AUG 30... -- <.01 .7 .02 -- <.20 -- -- .170 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 11... 6 <20.0 1130 <1 49 <.14 <2.6 <.43 E16 E.01 <16 .05 FEB 12... -- -- -- -- -- -- -- -- -- -- -- -- MAY 02... <1 <20.0 80 <1 24 <.01 <2.6 <.43 <31 <.01 <16 -- AUG 30... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 185 RIO DE LA PLATA BASIN 50045000 LAGO LA PLATA AT DAMSITE NEAR TOA ALTA, PR LOCATION.--Lat 18°20'40", long 66°14'10", Hydrologic Unit 21010005, 2.9 mi (4.7 km) at northeast of Plaza de Naranjito, 2.7 mi (4.3 km) West of Road 167, km 15.3, Buena Vista, Bayamón, 5.2 mi (8.4 km) east of Plaza de Corozal. DRAINAGE AREA.--181 mi2 (469 km2). ELEVATION RECORDS PERIOD OF RECORD.--February 1989 to current year. Prior to October 1994, published as Lago La Plata at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago La Plata first construction phase was completed in 1974 and the second construction phase to provide the spillway with bascule gates was completed in October 1989. The maximum storage is 37,000 ac-ft (45.6 hm3) and its purpose is the supply of water for domestic and industrial use. La Plata Dam is a concrete gravity structure located across the Rio de la Plata, the dam has an overall length of 774 ft (236 m) and a maximum height of about 131 ft (40 m). The dam spillway is provided with 6 bascule gates. The spillway crest has a total clear length of 690 ft (210 m), an elevation of 155 ft (47 m). The Dam is owned and operated by Puerto Rico Aqueduct and Sewer Authority. Gage-height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 00-40-45, October 1998. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 170.90 ft (52.09 m), Sept. 10, 1996; minimum elevation, 107.95 ft (32.90 m), Feb. 21, 1995. EXTREMES FOR CURRENT YEAR.--Maximum elevation, 166.55 ft (50.76 m), May.07; minimum elevation, 152.42 ft (46.46 m), Aug. 22. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 00-4045,Puerto Rico-1998) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 82 0 144 12,915 105 1,873 164 24,021 125 5,943 171 28,748 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 164.15 164.14 164.34 164.67 165.18 165.91 164.81 162.66 163.67 159.38 155.78 159.42 2 163.99 164.83 164.31 164.67 165.19 166.07 164.64 162.53 163.55 159.31 155.64 159.68 3 163.60 164.04 164.34 164.68 165.16 166.09 164.49 162.39 163.41 159.16 155.44 159.74 4 163.17 164.78 164.36 164.67 165.14 166.08 164.39 162.25 163.38 159.10 155.26 159.71 5 163.47 164.36 164.37 164.66 165.11 166.05 164.27 162.12 163.25 158.98 155.04 159.60 6 163.66 164.31 164.39 164.66 165.07 166.03 164.46 162.58 163.13 158.93 154.96 159.45 7 163.94 164.80 164.40 164.65 165.02 166.00 164.47 165.79 162.99 158.77 154.79 159.27 8 164.09 164.45 164.41 164.64 164.97 165.95 164.37 165.79 162.86 158.57 154.61 159.08 9 163.43 164.78 164.43 A 164.92 165.89 164.32 165.73 162.70 158.36 154.45 158.88 10 163.70 165.00 164.46 A 164.90 165.81 164.22 166.05 162.54 158.21 154.44 158.69 11 163.85 164.42 164.47 A 165.00 165.72 164.12 166.12 162.39 158.02 154.31 158.50 12 163.92 164.28 164.49 A 165.04 165.64 164.01 166.09 162.23 157.85 154.11 158.31 13 164.04 164.45 164.52 A 165.09 165.58 163.93 166.02 162.07 157.66 153.88 158.13 14 164.12 164.62 164.56 A 165.04 165.52 163.83 165.93 161.90 157.44 153.64 157.90 15 164.31 A 164.66 A 165.06 165.43 163.71 165.81 161.74 157.22 153.41 157.67 16 163.61 164.40 164.31 A 165.07 165.36 163.56 165.69 161.55 157.00 153.17 157.66 17 163.74 164.43 164.45 164.57 165.05 165.27 163.40 165.57 161.42 156.78 153.19 A 18 164.18 164.44 164.54 164.60 165.01 165.14 163.24 165.48 161.39 156.58 153.11 A 19 164.67 164.47 164.66 164.60 164.97 165.00 163.08 165.40 161.26 156.34 153.04 A 20 164.34 164.49 164.54 164.55 164.94 164.89 162.91 165.28 161.09 156.08 152.84 A 21 164.73 164.51 164.35 164.50 164.91 164.84 162.99 165.16 160.89 155.83 152.61 156.80 22 164.25 164.56 164.46 164.45 165.33 164.85 163.15 165.04 160.70 155.99 152.48 156.67 23 164.25 164.22 164.34 164.40 165.49 164.98 163.34 164.91 160.53 155.77 157.67 156.83 24 164.53 164.26 164.46 164.36 165.37 165.44 163.38 164.76 160.34 155.58 158.25 156.71 25 164.89 164.29 164.52 164.31 165.68 165.51 163.35 164.61 160.19 155.34 158.24 156.56 26 165.01 164.34 164.57 164.29 165.86 165.49 163.27 164.42 160.02 155.24 158.10 156.41 27 164.21 164.37 164.60 164.36 165.90 165.42 A 164.21 159.92 155.06 157.99 156.25 28 164.42 164.42 164.65 164.41 165.92 165.33 163.03 164.01 159.78 154.86 158.75 156.05 29 164.57 164.47 164.67 164.98 --- 165.23 162.89 163.86 159.60 155.36 159.58 155.85 30 164.90 164.53 164.67 165.08 --- 165.10 162.77 163.84 159.50 155.64 159.63 155.64 31 164.26 --- 164.67 165.14 --- 164.95 --- 163.75 --- 155.73 159.55 --- MAX 165.01 --- 164.67 --- 165.92 166.09 --- 166.12 163.67 159.38 159.63 --- MIN 163.17 --- 164.31 --- 164.90 164.84 --- 162.12 159.50 154.86 152.48 --- A No gage-height record 186 RIO DE LA PLATA BASIN 50045000 LAGO LA PLATA AT DAMSITE NEAR TOA ALTA, PR--Continued O N D 2000 J F M A M J J A S 2001 152 154 156 158 160 162 164 166 168 ELEVATION, IN FEET Gap indicates missing record 187 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM LOCATION.--Lat 18°20'45", long 66°14'17", Hydrologic Unit 21010005, 2.8 mi (4.5 km) west of Road 167, km 15.3, Buena Vista, Bayamón, 5.0 mi (8.0 km) east of Plaza de Corozal, 3.0 mi (4.8 km) northeast of Plaza de Naranjito. DRAINAGE AREA.--173 mi2 (448 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--July 1989 to current year. GAGE.--Water-stage recorder. Elevation of gage 66 ft (20 m), from topographic map. REMARKS.--Records poor. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 17 2120 338 1.1 1.3 3.1 2.5 1.6 2.0 .83 .34 26 2 770 4830 124 1.1 .66 2.9 1.6 1.2 2.0 .53 .16 25 3 944 2050 1.8 1.4 .61 2.3 1.3 1.1 1.8 .38 .10 23 4 401 132 1.9 1.6 .55 2.3 1.8 .94 2.2 .51 1.8 20 5 1.2 352 1.9 1.5 .76 2.4 1.7 1.2 1.7 .42 .30 18 6 1.1 169 1.9 1.6 .61 2.5 1.4 1.8 1.5 .39 .34 17 7 1.6 1.1 1.5 1.5 .68 2.5 2.0 658 1.8 .29 .14 16 8 1.1 440 1.9 1.3 .74 2.4 2.0 416 1.6 .20 .05 14 9 421 3.4 2.1 1.2 1.0 2.2 1.4 349 1.4 .12 .07 12 10 14 4.1 2.3 1.3 1.4 1.8 1.5 3.2 1.3 .14 .12 11 11 .94 265 2.1 2.2 1.3 1.8 2.0 2.6 1.2 .11 .09 9.4 12 .95 119 2.1 2.0 1.3 2.2 1.9 2.4 1.3 .09 .04 8.2 13 .68 3.3 2.9 2.1 1.4 2.3 1.8 3.4 1.4 .08 .02 6.9 14 .35 3.0 5.9 2.3 31 2.3 2.0 2.2 1.3 .07 .02 5.8 15 20 3.0 1.3 2.5 2.8 1.8 1.9 3.4 1.2 .06 .07 4.9 16 367 2.5 412 2.0 1.9 2.0 1.6 3.6 1.5 .05 .09 4.2 17 1.1 2.5 2.4 1.9 1.6 1.9 1.4 2.5 1.6 .04 .13 4.4 18 .87 3.1 1.5 1.8 1.6 1.9 1.3 2.3 1.7 .08 .10 3.8 19 2.3 2.9 1.3 1.7 1.8 2.2 1.5 1.8 1.8 .06 1.2 3.1 20 426 2.7 191 1.7 1.7 2.3 1.7 1.6 1.7 .03 .60 2.7 21 1.8 16 276 2.1 1.8 2.4 2.3 1.9 1.6 .02 .54 2.4 22 452 1.9 1.5 2.0 2.0 2.5 1.8 2.4 1.4 1.5 .82 2.1 23 965 353 426 2.0 2.0 2.4 1.9 1.9 1.5 .25 28 2.0 24 416 2.3 1.9 2.6 135 2.5 2.2 1.9 1.7 .06 45 1.8 25 .72 1.7 1.1 1.2 31 2.3 2.6 2.0 1.6 .01 38 1.6 26 28 1.7 1.1 1.3 3.1 2.3 2.1 2.0 1.2 .29 34 1.4 27 371 1.5 1.0 1.3 3.3 2.2 2.1 2.0 1.2 .10 30 1.2 28 1.5 1.5 1.3 1.7 3.0 2.4 2.1 1.9 1.2 .69 27 .92 29 1.0 1.4 1.3 1.8 --- 1.6 1.9 1.8 1.0 3.8 29 .68 30 .98 1.8 1.3 387 --- 1.7 1.8 2.0 1.0 .61 27 .50 31 492 --- .98 43 --- 1.9 --- 1.8 --- .15 26 --- TOTAL 6122.19 10891.4 1813.28 479.8 235.91 69.3 55.1 1481.44 45.4 11.96 291.14 250.00 MEAN 197 363 58.5 15.5 8.43 2.24 1.84 47.8 1.51 .39 9.39 8.33 MAX 965 4830 426 387 135 3.1 2.6 658 2.2 3.8 45 26 MIN .35 1.1 .98 1.1 .55 1.6 1.3 .94 1.0 .01 .02 .50 AC-FT 12140 21600 3600 952 468 137 109 2940 90 24 577 496 CFSM 1.14 2.10 .34 .09 .05 .01 .01 .28 .01 .00 .05 .05 IN. 1.32 2.34 .39 .10 .05 .01 .01 .32 .01 .00 .06 .05 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 2001, BY WATER YEAR (WY) MEAN 192 218 163 198 51.9 12.4 23.8 86.4 30.8 60.9 59.0 882 MAX 1107 1368 926 1581 241 83.2 231 494 220 384 322 8046 (WY) 1991 2000 1999 1992 1998 1990 1993 1993 1993 1993 2000 1996 MIN .048 .004 .000 .19 .14 .022 .011 .000 .002 .037 .020 .001 (WY) 1992 1995 1995 1990 1995 1995 1995 1994 1994 1994 1989 1991 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1989 - 2001 ANNUAL TOTAL 43036.62 21746.92 ANNUAL MEAN 118 59.6 168 HIGHEST ANNUAL MEAN 714 1996 LOWEST ANNUAL MEAN 8.62 1997 HIGHEST DAILY MEAN 8370 Aug 23 4830 Nov 2 141000 Sep 10 1996 LOWEST DAILY MEAN .00 Sep 7 .01 Jul 25 .00 Jul 14 1989 ANNUAL SEVEN-DAY MINIMUM .11 Jun 5 .05 Jul 15 .00 Jul 14 1989 MAXIMUM PEAK FLOW 31500 Nov 2 197000 Sep 10 1996 MAXIMUM PEAK STAGE 19.77 Nov 2 42.26 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 85360 43140 121700 ANNUAL RUNOFF (CFSM) .68 .34 .97 ANNUAL RUNOFF (INCHES) 9.26 4.68 13.21 10 PERCENT EXCEEDS 335 32 201 50 PERCENT EXCEEDS 2.1 1.8 1.5 90 PERCENT EXCEEDS .48 .32 .00 188 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM--Continued O N D 2000 J F M A M J J A S 2001 0.01 0.02 0.05 0.1 0.1 0.2 0.5 1 2 5 10 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 189 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HIGHWAY 2 NEAR TOA ALTA, PR LOCATION.--Lat 18°24'41", long 66°15'39", Hydrologic Unit 21010005, on left bank, at downstream side of bridge on Highway 2, 1.3 mi ( 2.1 km) downstream from Río Lajas, and 1.6 mi (2.6 km) northwest of Toa Alta, 11.3 mi (18.2 km) downstream from Puerto Rico Aqueduct and Sewer Authority reservoir. DRAINAGE AREA.--208 mi2 (539 km2), excludes 8.2 mi2 (21.2 km2) upstream from Lago Carite, flow from which is diverted to Río Guamaní. Area at site used prior to September 25, 1984, 200 mi2 (518 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1959 (measurement only), January 1960 to current year. Prior to October 1984, published as Río de la Plata at Toa Alta, PR; October 1984 to September 1988 published as 50046900. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 9.15 ft (2.789 m), above mean sea level. Prior to October, 1984, at site about 1.0 mi (1.6 km) upstream at mean sea level datum. REMARKS.--Records poor. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. Gage-height and precipitation satellite telemetry at station. Flow affected by water extraction for La Virgencita water treatment plant by Puerto Rico Aqueduct and Sewer Authority of about 3.99 ft3/s (0.11 m3/s). Located about 1,000 ft upstream from station. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate discharges and elevations of major floods, as pointed out by local residents are as follows: Sept. 13, 1928, 120,000 ft3/s (3,400 m3/s), gage height, 37.4 ft (11.40 m); June 16, 1943, 82,000 ft3/s (2,322 m3/s), gage height, 34.4 ft (10.48 m), at site 1.0 mi upstream and different datum. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 130 1530 85 23 33 27 15 24 52 27 74 122 2 668 7260 449 23 27 34 15 20 41 23 47 65 3 1140 5480 39 32 28 22 16 19 33 18 28 111 4 944 550 29 29 23 20 22 18 33 59 23 110 5 80 239 25 26 21 20 16 18 43 34 22 92 6 50 522 25 23 20 20 14 40 34 18 150 53 7 157 93 24 23 21 20 15 805 27 17 100 46 8 134 537 24 22 21 19 16 974 27 17 34 45 9 197 98 23 21 21 20 19 997 26 18 32 44 10 442 61 24 22 23 22 13 144 27 22 54 56 11 118 56 25 20 56 21 17 66 26 29 65 45 12 64 461 27 e20 46 22 13 46 26 23 53 42 13 52 58 34 22 29 24 13 39 28 20 31 38 14 79 53 28 26 26 48 14 35 26 16 29 32 15 75 81 44 35 57 22 12 34 25 16 28 31 16 485 66 271 32 39 20 12 34 26 16 26 30 17 70 43 383 33 36 17 12 34 28 14 27 65 18 48 44 65 29 24 19 14 34 55 17 30 153 19 44 43 e50 29 23 21 13 46 40 20 135 71 20 434 42 e42 28 26 24 15 34 25 16 90 34 21 178 44 472 27 33 22 32 31 26 17 33 28 22 410 74 52 27 300 22 30 30 27 62 38 28 23 1010 349 394 28 39 22 32 29 92 58 311 26 24 1130 99 147 28 56 22 39 27 72 26 97 25 25 151 43 36 27 247 23 32 26 56 20 73 24 26 68 40 30 28 38 19 22 29 35 92 61 24 27 501 38 28 31 26 17 e18 30 27 79 58 27 28 106 31 25 58 24 17 e18 30 25 26 83 29 29 65 30 24 69 --- 18 18 26 22 643 65 26 30 51 28 25 356 --- 17 19 42 25 292 68 26 31 655 --- 24 181 --- 14 --- 47 --- 57 53 --- TOTAL 9736 18093 2973 1378 1363 675 556 3808 1055 1812 2018 1548 MEAN 314 603 95.9 44.5 48.7 21.8 18.5 123 35.2 58.5 65.1 51.6 MAX 1140 7260 472 356 300 48 39 997 92 643 311 153 MIN 44 28 23 20 20 14 12 18 22 14 22 24 AC-FT 19310 35890 5900 2730 2700 1340 1100 7550 2090 3590 4000 3070 CFSM 1.51 2.90 .46 .21 .23 .10 .09 .59 .17 .28 .31 .25 IN. 1.74 3.24 .53 .25 .24 .12 .10 .68 .19 .32 .36 .28 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1960 - 2001, BY WATER YEAR (WY) MEAN 460 457 341 184 128 91.8 167 312 150 140 241 429 MAX 4813 2015 1352 929 409 468 722 1939 847 690 1677 3173 (WY) 1971 1985 1971 1992 1989 1969 1987 1985 1970 1961 1979 1996 MIN 18.8 18.4 14.8 16.9 16.0 8.31 5.07 7.63 11.4 13.2 16.5 19.2 (WY) 1995 1995 1995 1984 1983 1986 1984 1984 1977 1994 1976 1991 190 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HIGHWAY 2 NEAR TOA ALTA, PR--Continued SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1960 - 2001 ANNUAL TOTAL 74735.4 45015 ANNUAL MEAN 204 123 257 HIGHEST ANNUAL MEAN 824 1971 LOWEST ANNUAL MEAN 31.5 1994 HIGHEST DAILY MEAN 11100 Aug 23 7260 Nov 2 68100 Sep 10 1996 LOWEST DAILY MEAN 9.4 Aug 8 12 Apr 15 2.7 Apr 17 1984 ANNUAL SEVEN-DAY MINIMUM 13 Jul 22 13 Apr 12 2.9 Apr 15 1984 MAXIMUM PEAK FLOW 34500 Nov 2 160000 Sep 10 1996 MAXIMUM PEAK STAGE 21.07 Nov 2 27.33 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 148200 89290 185900 ANNUAL RUNOFF (CFSM) .98 .59 1.23 ANNUAL RUNOFF (INCHES) 13.37 8.05 16.76 10 PERCENT EXCEEDS 461 179 477 50 PERCENT EXCEEDS 36 30 78 90 PERCENT EXCEEDS 18 18 18 e Estimated O N D 2000 J F M A M J J A S 2001 10 20 50 100 100 200 500 1000 1000 2000 5000 10,000 DISCHARGE, IN CUBIC FEET PER SECOND 191 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HWY 2 NR TOA ALTA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'41", long 66°15'39", at Highway 2, 1.3 mi (2.1 km) downstream from Río Lajas, and 1.6 mi (2.6 km) northwest of Toa Alta, 11.3 mi (18.2 km) downstream from Lago La Plata. DRAINAGE AREA.--208 mi2 (539 km2), exclude 8.2 mi2 (21.2 km2) upstream from Lago Carite, flow from which is diverted to Río Guamaní. PERIOD OF RECORD.--Water years 1958 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 11... 1340 68 340 7.3 28.6 34 5.9 76 19 5800 2600 130 38.1 FEB 07... 1130 21 445 7.5 25.6 2.7 5.7 70 12 310 <10 -- -- APR 23... 1300 35 488 7.4 28.3 2.0 6.0 77 <10 430 210 180 50.5 AUG 16... 1050 24 481 7.1 30.4 -- 4.9 65 20 270 E120 180 55.5 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 11... 8.12 15.6 .6 3.11 128 <1.0 12.5 19.0 E.1 17.3 191 34.8 28 FEB 07... -- -- -- -- 163 -- -- -- -- -- -- -- 14 APR 23... 12.2 27.3 .9 3.39 171 <1.0 14.9 37.6 E.1 20.9 269 25.1 <10 AUG 16... 11.0 24.6 .8 3.19 185 -- 17.0 33.3 E.1 19.2 275 17.5 <10 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) OCT 11... .67 .04 .7 .18 .39 .57 1.3 5.7 .090 E2 51.2 43 <.11 FEB 07... .93 .07 1.0 .19 .37 .56 1.6 6.9 .060 -- -- -- -- APR 23... .98 .12 1.1 .23 .45 .68 1.8 7.9 .130 E2 54.5 64 <.11 AUG 16... .74 .04 .8 .05 .41 .46 1.2 5.5 .030 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 11... 2 <20.0 810 <1 96 <.14 <2.6 <.43 <31 <.01 <16 .04 FEB 07... -- -- -- -- -- -- -- -- -- -- -- -- APR 23... <1 <20.0 60 M 68 <.01 <2.6 <.43 <31 <.01 <16 .06 AUG 16... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 192 THIS PAGE IS INTENTIONALLY BLANK 193 Figure 17. Río Hondo to Río Puerto Nuevo basins. 194 RIO HONDO BASIN 50047530 RIO HONDO AT FLOOD CHANNEL NEAR CATAÑO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°26'13", long 66°09'36", at Río Hondo Channel, 800 ft (245 m) below junction with Río Hondo, 0.9 mi (1.5 km) downstream from bridge on de Diego Expressway and 1.1 mi (1.8 km) above mouth. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 PH OXYGEN, OXYGEN COLI- FECAL SPE- WATER DIS- DEMAND, FORM, STREP, HARD- MAGNE- CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM SIUM, CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- DIS- DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED SOLVED DATE TIME ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L (MG/L (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) AS MG) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) (00925) OCT 03... 1340 29800 8.1 30.3 21 10.6 156 150 4300 5700 3200 198 657 FEB 05... 1345 14400 7.7 27.0 5.5 3.3 43 <40 E1700 540 -- -- -- APR 23... 1600 4790 7.5 28.5 25 2.7 35 46 5900 800 860 72.7 165 ANC SOLIDS, RESIDUE SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF TOTAL NITRO- NITRO- SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- AT 105 GEN, GEN, DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, DEG. C, NITRATE NITRITE SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- SUS- TOTAL TOTAL DATE (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PENDED (MG/L (MG/L AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) (MG/L) AS N) AS N) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (00530) (00620) (00615) OCT 03... 5400 42 208 128 <1.0 1410 10400 .4 4.4 18400 90 .02 .01 FEB 05... -- -- -- 157 -- -- -- -- -- -- 20 .09 .06 APR 23... 1370 20 49.3 118 <1.0 348 2610 .3 10.8 4700 35 .13 .04 NITRO- CHRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 03... M .05 .68 .73 .76 3.4 .130 E2 73.6 2330 <.22 <1 <200 FEB 05... .1 1.20 .50 1.7 1.8 8.2 .190 -- -- -- -- -- -- APR 23... .2 .71 .69 1.4 1.6 6.9 .260 3 37.7 657 <.22 1 <20.0 MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 03... 610 <4 282 <.14 <2.6 <.43 <310 <.01 <16 .03 FEB 05... -- -- -- -- -- -- -- -- -- -- APR 23... 770 3 185 <.01 <2.6 <.43 <31 <.01 <16 .49 < -- Less than M -- Presence verified, not quantified E -- Estimated value 195 RIO DE BAYAMON BASIN 50047535 RIO DE BAYAMON AT ARENAS, PR LOCATION.--Lat 18°10'11", long 66°07'18", Hydrologic Unit 21010005, at left bank, 2.6 mi (4.2 km) southeast of plaza de Cidra, 0.6 mi (0.9 km) southwest from Escuela Segunda Unidad de Bayamón, and 2.7 mi (4.3 km) northeast from Central Cayey. DRAINAGE AREA.--0.45 mi2 (1.16 km2). PERIOD OF RECORD.--July 1992 to September 1993, October 1995 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,378 ft (420 m), from topographic map. REMARKS.--Records fair, except those for estimated daily discharges, which are poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e.24 4.0 e.49 e.19 e.37 .16 e.12 .32 .23 .21 .15 .77 2 e.49 1.1 e.33 e.22 e.26 .16 e.13 .26 .21 .19 .13 .45 3 e.67 1.7 e.28 e.20 e.32 .16 .17 .23 .18 .17 .13 .28 4 e.32 .42 e.25 e.21 e.25 .16 .17 .21 .18 .17 .31 .22 5 e.24 .29 e.25 e.20 e.23 .17 1.6 .19 .29 .27 .20 .18 6 e.21 .26 e.24 e.17 e.23 .16 .33 .51 .20 .14 .22 .16 7 e.20 .61 e.24 e.15 e.21 .15 .21 8.4 .18 .13 .21 .15 8 e.21 .38 e.23 e.15 e.19 .15 .24 .51 .17 .12 .16 .23 9 e.33 .28 e.23 e.14 e.21 .15 .23 .32 .16 .11 .15 .19 10 e.30 .25 e.24 e.14 e.25 .14 .17 .22 .17 .11 .16 .18 11 e.23 .24 e.24 e.15 e.50 .13 .32 .21 .16 .12 .15 .42 12 e.25 .25 e.26 e.16 e.66 .12 .20 .21 .15 .12 .18 .34 13 e.22 e.25 e.25 e.16 e.24 .12 .43 .20 .15 .16 .17 .21 14 e.19 e.28 e.35 e.16 e.29 .13 .32 .19 .14 .12 e.50 .17 15 e.22 .39 e.53 e.16 e.40 .12 .21 .18 .14 .11 e.12 .16 16 e.19 .36 e.95 e.22 e.38 .12 .19 .17 .14 .11 e.13 .13 17 .20 .29 e.64 e.22 .36 .13 .16 .17 .14 .10 e.78 .25 18 .19 .30 e2.2 e.20 .25 .11 .15 .21 .15 .11 e.46 .19 19 .22 .29 1.4 e.20 .23 .11 .15 .22 .14 .13 e.14 .16 20 .22 .29 1.9 e.19 .26 .12 .15 .17 .14 .11 .12 .14 21 .32 .53 .67 e.25 .25 .18 .30 .16 .13 .09 .36 .13 22 .34 .55 5.4 e.27 .28 .27 .52 .20 .14 .09 .94 .12 23 2.0 e.31 1.3 e.25 .22 4.1 .55 .18 .14 .10 2.9 .12 24 .46 e.38 .47 e.24 .43 .84 2.2 .18 .14 .13 .43 .12 25 .31 e.34 .46 e.22 .32 .32 .60 .20 .21 .30 .20 .12 26 .33 e.32 .30 e.22 .24 .23 .36 .19 .19 .19 .15 .12 27 .24 e.30 .24 e.23 .20 .19 e.29 .18 .15 .15 .13 .11 28 .46 e.29 .21 e.29 .17 e.16 e.26 .40 .17 .11 10 .11 29 .37 e.28 e.23 e4.3 --- e.14 .27 .19 .15 .51 .84 .10 30 .31 e1.1 e.18 e1.1 --- e.12 .25 .20 .16 .37 .39 .11 31 .29 --- e.16 e.29 --- e.14 --- .31 --- .22 .28 --- TOTAL 10.77 16.63 21.12 11.25 8.20 9.46 11.25 15.49 5.00 5.07 21.19 6.14 MEAN .35 .55 .68 .36 .29 .31 .38 .50 .17 .16 .68 .20 MAX 2.0 4.0 5.4 4.3 .66 4.1 2.2 8.4 .29 .51 10 .77 MIN .19 .24 .16 .14 .17 .11 .12 .16 .13 .09 .12 .10 AC-FT 21 33 42 22 16 19 22 31 9.9 10 42 12 CFSM .77 1.23 1.51 .81 .65 .68 .83 1.11 .37 .36 1.52 .45 IN. .89 1.37 1.75 .93 .68 .78 .93 1.28 .41 .42 1.75 .51 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1992 - 2001, BY WATER YEAR (WY) MEAN .69 1.20 1.17 .66 .61 .27 .23 .48 .55 .76 .96 2.25 MAX 1.73 3.82 4.63 1.17 2.38 .65 .45 2.02 1.79 2.12 1.87 6.52 (WY) 1998 2000 1999 2000 1998 1998 1993 1993 1996 1993 1996 1998 MIN .30 .32 .048 .36 .16 .097 .095 .10 .10 .092 .46 .20 (WY) 1997 1998 1998 2001 1993 1993 1997 1999 1998 1998 1992 1997 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1992 - 2001 ANNUAL TOTAL 203.89 141.57 ANNUAL MEAN .56 .39 .83 HIGHEST ANNUAL MEAN 1.16 1996 LOWEST ANNUAL MEAN .31 1997 HIGHEST DAILY MEAN 34 Aug 23 10 Aug 28 141 Sep 10 1996 LOWEST DAILY MEAN .05 May 7 .09 Jul 21 .02 Jul 3 1997 ANNUAL SEVEN-DAY MINIMUM .06 May 2 .10 Jul 17 .03 Jun 28 1997 MAXIMUM PEAK FLOW 126 Aug 28 1150 Sep 21 1998 MAXIMUM PEAK STAGE 4.32 Aug 28 7.89 Sep 21 1998 INSTANTANEOUS LOW FLOW .08 Jul 24 .02 Jul 15 1997 ANNUAL RUNOFF (AC-FT) 404 281 603 ANNUAL RUNOFF (CFSM) 1.24 .86 1.85 ANNUAL RUNOFF (INCHES) 16.85 11.70 25.14 10 PERCENT EXCEEDS .84 .51 1.1 50 PERCENT EXCEEDS .26 .21 .20 90 PERCENT EXCEEDS .11 .13 .07 e Estimated 196 RIO DE BAYAMON BASIN 50047535 RIO DE BAYAMON AT ARENAS, PR--Continued O N D 2000 J F M A M J J A S 2001 0.01 0.02 0.05 0.1 0.1 0.2 0.5 1 2 5 10 DISCHARGE, IN CUBIC FEET PER SECOND 197 RIO DE BAYAMON BASIN 50047540 RIO SABANA AT VISTA MONTE, PR LOCATION.--Lat 18°10'28", long 66°08'38", Hydrologic Unit 21010005, at left bank, 1.2 mi (1.9 km) southeast of Plaza de Cidra, 1.2 mi (1.9 km) southwest from Escuela Segunda Unidad de Bayamón, and 0.4 mi (0.6 km) upstream from Lago de Cidra. DRAINAGE AREA.--0.80 mi2 (2.07 km2). PERIOD OF RECORD.--August 1992 to September 1993, October 1995 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 1,345 ft (410 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e.63 2.7 e.77 .45 .61 .38 .21 .23 .28 .23 e.19 e.69 2 e2.4 4.4 e.57 .49 .46 .39 .21 .17 .21 .26 e.17 e.35 3 e2.0 3.1 e.50 .47 .53 .38 .20 .15 .19 .18 e.17 e.27 4 e.95 .95 e.47 .48 .42 .40 .22 .15 .17 .36 e.37 e.23 5 e.65 .64 e.47 .47 .39 .34 1.0 .15 .21 .39 e.21 e.21 6 e.49 .58 e.46 .40 .40 .31 .67 2.3 .18 .19 e.29 e.20 7 e.42 .65 e.45 .38 .36 .30 .27 8.6 .17 .15 e.25 e.18 8 e.53 .66 e.44 .35 .34 .29 1.9 .59 .17 .14 e.22 e.26 9 e1.2 .58 e.44 .31 .39 .30 .37 .62 .18 .15 e.21 e.21 10 e.59 .49 e.45 .30 .43 .31 .25 .40 .20 .15 e.23 e.21 11 e.55 .46 e.45 .32 .77 .29 .39 .31 .20 .16 e.22 e.42 12 e.59 .47 e.48 .33 .97 .25 .58 .28 .19 e.19 e.24 e.31 13 e.53 .47 e.47 .33 .44 .21 .38 .23 .18 e.18 e.28 e.23 14 e.53 1.1 e.59 .33 .51 .22 .24 .22 .18 e.15 e.39 e.18 15 e.52 .74 e.82 .33 .64 .21 .22 .22 .18 e.14 e.22 e.18 16 .51 .51 1.5 .41 .58 .21 .21 .23 .17 e.14 e.23 e.14 17 .57 .50 1.2 .41 .51 .17 .22 .22 2.0 e.13 e.51 e.25 18 .53 .56 3.2 .38 .45 .17 .21 .38 .21 e.15 e.37 e.18 19 .81 .55 2.1 .38 .42 .18 .21 .29 .17 e.16 e.23 e.16 20 .58 .56 2.4 .37 .45 .22 .21 .23 .16 e.14 e.42 e.16 21 1.0 1.0 1.5 .44 .47 .62 .60 .22 .16 e.13 e.36 e.15 22 .60 e.85 7.0 .47 .57 .25 .76 .26 .16 e.13 e1.3 e.15 23 4.9 e.54 3.0 .45 .43 4.7 .31 .23 .15 e.12 e1.1 e.15 24 1.1 e.63 1.1 .44 1.3 .52 2.3 .23 .21 e.23 e.43 e.14 25 .68 e.58 .95 .41 .73 .26 .37 .28 .44 e.19 e.28 e.15 26 .57 e.55 .60 .41 .47 .23 .21 .21 .30 e.23 e.25 e.14 27 .48 e.53 .48 .42 .42 .22 .18 .20 .22 e.17 e.23 e.13 28 1.5 e.52 .48 .50 .41 .22 .18 .68 .21 e.15 e4.5 e.13 29 1.1 e.50 .50 5.6 --- .23 .17 .23 .18 e.54 e.59 e.13 30 .74 e1.7 .40 1.5 --- .21 .23 .25 .21 e.33 e.37 e.13 31 .64 --- .37 .49 --- .22 --- .60 --- e.24 e.28 --- TOTAL 28.89 28.07 34.61 18.82 14.87 13.21 13.48 19.36 7.84 6.20 15.11 6.42 MEAN .93 .94 1.12 .61 .53 .43 .45 .62 .26 .20 .49 .21 MAX 4.9 4.4 7.0 5.6 1.3 4.7 2.3 8.6 2.0 .54 4.5 .69 MIN .42 .46 .37 .30 .34 .17 .17 .15 .15 .12 .17 .13 AC-FT 57 56 69 37 29 26 27 38 16 12 30 13 CFSM 1.16 1.17 1.40 .76 .66 .53 .56 .78 .33 .25 .61 .27 IN. 1.34 1.31 1.61 .88 .69 .61 .63 .90 .36 .29 .70 .30 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1992 - 2001, BY WATER YEAR (WY) MEAN 1.88 2.09 1.98 1.00 1.06 .50 .56 .68 .71 1.17 1.51 4.55 MAX 4.51 5.02 7.83 1.91 3.50 1.01 1.23 2.26 1.57 3.02 3.44 16.7 (WY) 1998 2000 1999 1999 1998 1998 1993 1993 1999 1993 2000 1996 MIN .76 .86 .31 .33 .33 .15 .19 .20 .25 .20 .48 .21 (WY) 1997 1998 1998 1998 1993 1993 2000 2000 1997 2001 1997 2001 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1992 - 2001 ANNUAL TOTAL 350.71 206.88 ANNUAL MEAN .96 .57 1.51 HIGHEST ANNUAL MEAN 2.37 1998 LOWEST ANNUAL MEAN .57 2001 HIGHEST DAILY MEAN 84 Aug 23 8.6 May 7 401 Sep 10 1996 LOWEST DAILY MEAN .08 Jun 8 .12 Jul 23 .08 Jun 8 2000 ANNUAL SEVEN-DAY MINIMUM .09 Jun 5 .14 Sep 24 .09 Jun 5 2000 MAXIMUM PEAK FLOW 52 Oct 23 2380 Sep 10 1996 MAXIMUM PEAK STAGE 2.46 Oct 23 12.02 Sep 10 1996 INSTANTANEOUS LOW FLOW .07 Jun 8 2000 ANNUAL RUNOFF (AC-FT) 696 410 1100 ANNUAL RUNOFF (CFSM) 1.20 .71 1.89 ANNUAL RUNOFF (INCHES) 16.31 9.62 25.68 10 PERCENT EXCEEDS 1.5 .98 1.7 50 PERCENT EXCEEDS .45 .37 .47 90 PERCENT EXCEEDS .15 .17 .19 e Estimated 198 RIO DE BAYAMON BASIN 50047540 RIO SABANA AT VISTA MONTE, PR--Continued O N D 2000 J F M A M J J A S 2001 0.1 0.2 0.5 1 2 5 10 DISCHARGE, IN CUBIC FEET PER SECOND 199 RIO DE BAYAMON BASIN 50047550 LAGO CIDRA AT DAMSITE NEAR CIDRA, PR LOCATION.--Lat 18°11'57", long 66°08'29", Hydrologic Unit 21010005, at Lago de Cidra Dam on Río de Bayamón, 1.9 mi (3.0 km) northeast of Plaza de Cidra and 1.8 mi (2.9 km) northwest of Escuela Segunda Unidad de Bayamón. DRAINAGE AREA.--8.26 mi2 (21.39 km2). ELEVATION RECORDS PERIOD OF RECORD.--January 1988 to current year. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago de Cidra was completed in 1946. The maximum storage is 5,300 ac-ft (6.53 hm3) and provides supplemental water to metropolitan San Juan. The dam is a concrete gravity and earthfill structure approximately 541 ft (165 m) long between abutments with a maximum structural height of about 78.7 ft (24.0 m). The spillway portion of the dam, length 131 ft (40 m) and crest elevation 1,322 ft (403 m), is an ungated ogee crest located 131 ft (40 m) from the right abutment. This dam is owned by Puerto Rico Aqueduct and Sewer Authority. Gage-height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 99-4144,November 1997. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 1,328.09 ft (404.80 m), Sep. 10, 1996; minimum elevation 1,295.86 ft (394.98 m), April 22,1995. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 1,314.84 ft (400.76 m), Feb.17; minimum elevation, 1,297.16ft (395.37 m), July 21. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 99-4144,Puerto Rico-1997) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 1,260 0 1,309 2,059 1,276 97 1,315 3,170 1,296 762 1,322 4,670 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1312.21 1313.66 A 1312.83 1313.73 1314.36 A 1309.49 1307.99 1301.52 1299.11 1304.86 2 1312.95 1313.99 A 1312.83 1313.86 1314.24 1311.53 1309.27 1307.92 1301.39 1299.19 1304.82 3 1313.12 1314.19 A 1312.84 1313.98 1314.10 1311.42 1309.06 1307.81 1301.15 1299.27 1304.78 4 1313.17 1314.17 A 1312.84 1314.08 1313.96 1311.29 1308.90 1307.63 1301.00 1299.30 1304.73 5 1313.21 1314.15 A 1312.83 1314.17 1313.83 1311.25 1308.72 1307.48 1301.01 1299.27 1304.65 6 1313.26 1314.05 1311.07 1312.82 1314.24 1313.70 1311.16 1308.85 1307.31 1300.76 1299.31 1304.60 7 1313.28 1313.93 1311.03 1312.80 1314.24 1313.61 1311.05 1309.72 1307.08 1300.25 1299.41 1304.53 8 1313.39 1313.79 1310.94 1312.78 1314.21 1313.56 1311.15 1309.67 1306.86 A 1299.49 1304.48 9 1313.42 1313.64 1310.79 1312.76 1314.29 1313.52 1311.07 1309.68 1306.63 A 1299.56 1304.42 10 1313.46 1313.49 1310.67 1312.73 1314.28 1313.44 1310.97 1309.75 1306.41 A 1299.71 1304.37 11 1313.45 1313.33 1310.56 1312.70 1314.35 1313.32 1310.94 1309.79 1306.20 A 1299.87 1304.34 12 1313.40 1313.17 1310.44 1312.66 1314.43 1313.22 1310.97 1309.86 1305.97 1298.19 1300.00 1304.31 13 1313.35 1313.01 1310.35 1312.63 1314.48 1313.12 1310.97 1309.89 1305.73 1297.81 1300.11 1304.26 14 1313.28 1312.92 1310.41 1312.59 1314.57 1312.99 1310.86 1309.90 1305.51 1297.88 1300.25 1304.20 15 1313.23 1312.77 1310.79 1312.56 1314.70 1312.81 1310.75 1309.79 1305.29 1297.90 1300.30 1304.23 16 1313.17 1312.57 1310.97 1312.52 1314.83 1312.69 1310.63 1309.71 1305.05 1297.76 1300.33 1304.29 17 1313.11 1312.38 1311.08 1312.44 1314.82 1312.59 1310.50 1309.59 1305.48 1297.61 1300.49 1304.33 18 1313.06 1312.19 1311.40 1312.42 1314.79 1312.49 1310.37 1309.53 1305.26 1297.52 1300.58 1304.28 19 1313.06 1311.98 1311.56 1312.42 1314.74 1312.39 1310.22 1309.44 1305.01 1297.42 1300.68 1304.24 20 1313.04 1311.78 1311.72 1312.42 1314.66 1312.31 1310.07 1309.31 1304.74 1297.26 1300.78 1304.17 21 1313.09 1311.66 1311.84 1312.40 1314.53 1312.28 1310.04 1309.16 1304.41 1297.18 1301.00 1304.11 22 1313.08 1311.48 1312.53 1312.42 1314.46 1312.22 1310.10 1309.11 1304.10 1297.20 1301.67 1304.05 23 1313.66 1311.32 1312.67 1312.41 1314.45 1312.55 1310.12 1309.00 1303.78 1297.20 1302.95 1303.99 24 1313.70 1311.17 1312.76 1312.39 1314.62 1312.47 1310.44 1308.88 1303.47 1297.21 1302.99 1303.93 25 1313.67 1311.06 1312.85 1312.39 1314.65 1312.36 1310.39 1308.78 1303.24 1297.55 1302.95 1303.86 26 1313.56 1310.92 1312.89 1312.37 1314.58 1312.25 1310.35 1308.60 1302.93 1297.70 1302.90 1303.80 27 1313.46 1310.81 1312.90 1312.36 1314.52 1312.15 A 1308.40 1302.60 1297.83 1302.88 1303.74 28 1313.47 1310.75 1312.88 1312.38 1314.47 1312.04 1310.10 1308.31 1302.25 1297.95 1304.87 1303.67 29 1313.40 1310.73 1312.85 1313.29 --- 1311.99 1309.88 1308.18 1301.92 1298.88 1304.89 1303.61 30 1313.30 1310.94 1312.83 1313.48 --- --- 1309.69 1308.07 1301.71 1298.97 1304.85 1303.54 31 1313.16 --- 1312.84 1313.59 --- --- --- 1308.03 --- 1299.02 1304.80 --- MAX 1313.70 1314.19 --- 1313.59 1314.83 --- --- 1309.90 1307.99 --- 1304.89 1304.86 MIN 1312.21 1310.73 --- 1312.36 1313.73 --- --- 1308.03 1301.71 --- 1299.11 1303.54 A No gage-height record 200 RIO DE BAYAMON BASIN 50047550 LAGO CIDRA AT DAMSITE NEAR CIDRA, PR--Continued O N D 2000 J F M A M J J A S 2001 1295 1300 1305 1310 1315 ELEVATION, IN FEET Gap indicates missing record 201 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.--8.32 mi2 (21.5 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,279 ft (390 m), from topographic map. REMARKS.--Records poor. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 4.0 28 e4.3 7.5 5.6 14 15 18 e18 18 2.4 3.1 2 4.5 16 4.3 6.7 5.5 14 15 16 e14 17 2.4 2.9 3 3.9 7.5 3.9 6.5 5.4 17 16 15 e15 17 2.3 2.9 4 3.8 6.9 4.2 6.8 4.9 16 18 14 e20 17 2.3 2.8 5 4.5 e6.2 4.4 7.4 5.0 14 19 16 e22 12 2.4 2.8 6 4.9 e5.8 4.8 6.3 7.4 16 19 18 e23 43 2.4 2.7 7 5.5 e5.3 3.9 7.3 10 12 18 17 e23 59 2.3 2.6 8 5.6 e5.1 7.9 7.2 10 12 18 8.4 e22 9.4 2.2 2.5 9 6.1 e5.6 12 7.0 10 12 15 8.1 e23 34 2.2 2.5 10 5.8 e5.4 11 7.6 11 12 14 7.9 e25 38 2.2 2.5 11 7.7 e5.5 e11 7.8 11 10 12 7.4 e23 23 2.2 2.4 12 11 e4.9 e12 8.1 12 14 14 7.5 e21 23 2.4 2.4 13 13 e14 7.3 8.5 8.4 16 17 11 e17 21 2.4 2.3 14 12 e13 4.6 8.5 7.0 16 16 13 e28 2.7 2.4 2.3 15 12 e12 4.9 8.3 6.5 17 16 16 e30 4.8 2.5 2.3 16 12 e12 6.2 7.6 7.7 15 16 19 e37 6.2 2.4 2.3 17 13 e12 4.9 7.3 20 15 17 19 e35 5.9 2.5 2.6 18 11 e4.8 5.3 6.3 19 15 19 19 e25 5.2 2.4 2.4 19 10 e4.9 e5.1 6.3 18 15 19 19 e21 5.2 2.3 2.5 20 10 e5.5 e5.5 6.6 24 16 17 18 e18 7.9 2.4 2.6 21 12 e5.5 5.1 6.8 38 16 17 19 e21 6.2 2.5 2.5 22 12 e4.8 e5.7 6.6 30 17 18 20 19 2.4 3.2 2.5 23 9.9 e5.0 e5.3 7.0 17 19 12 19 18 2.4 2.9 2.4 24 6.2 e5.1 e5.3 6.5 15 20 11 17 21 2.4 2.3 2.5 25 17 e5.0 e4.8 6.2 15 18 10 21 20 2.5 2.4 2.5 26 25 e4.6 e4.8 6.4 14 18 11 26 20 2.3 2.5 2.4 27 24 e4.9 e4.8 6.9 13 16 14 30 e20 2.3 2.4 2.4 28 24 e5.0 e10 7.5 14 17 18 34 19 2.2 5.6 2.3 29 23 e5.2 e10 9.7 --- 17 18 26 19 2.8 3.4 2.1 30 24 e4.1 10 5.5 --- 19 18 e19 18 2.3 3.3 2.1 31 26 --- 7.9 5.7 --- 19 --- e16 --- 2.3 3.2 --- TOTAL 363.4 229.6 201.2 220.4 364.4 484 477 534.3 655 399.4 80.7 75.1 MEAN 11.7 7.65 6.49 7.11 13.0 15.6 15.9 17.2 21.8 12.9 2.60 2.50 MAX 26 28 12 9.7 38 20 19 34 37 59 5.6 3.1 MIN 3.8 4.1 3.9 5.5 4.9 10 10 7.4 14 2.2 2.2 2.1 AC-FT 721 455 399 437 723 960 946 1060 1300 792 160 149 CFSM 1.41 .92 .78 .85 1.56 1.88 1.91 2.07 2.62 1.55 .31 .30 IN. 1.62 1.03 .90 .99 1.63 2.16 2.13 2.39 2.93 1.79 .36 .34 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1991 - 2001, BY WATER YEAR (WY) MEAN 15.8 21.7 29.2 19.4 17.8 17.2 14.5 13.2 12.7 14.0 13.5 38.7 MAX 31.2 41.2 117 59.6 36.5 26.3 24.5 23.2 21.8 39.6 29.2 233 (WY) 1999 1992 2000 1992 1991 1998 1996 1998 2001 1993 1996 1996 MIN 3.74 7.65 4.36 5.45 7.24 11.4 5.72 4.13 3.47 1.56 1.18 1.64 (WY) 1995 2001 1994 1995 1994 1994 1997 1993 1994 1994 1995 1994 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1991 - 2001 ANNUAL TOTAL 5853.8 4084.5 ANNUAL MEAN 16.0 11.2 19.0 HIGHEST ANNUAL MEAN 36.1 1996 LOWEST ANNUAL MEAN 5.93 1994 HIGHEST DAILY MEAN 497 Jan 3 59 Jul 7 5420 Sep 10 1996 LOWEST DAILY MEAN 2.0 Jan 20 2.1 Sep 29 .60 Aug 6 1992 ANNUAL SEVEN-DAY MINIMUM 3.1 Jan 18 2.3 Aug 5 .80 May 1 1995 MAXIMUM PEAK FLOW 132 Jul 6 15000 Sep 10 1996 MAXIMUM PEAK STAGE 9.81 Jul 6 27.34 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 11610 8100 13750 ANNUAL RUNOFF (CFSM) 1.92 1.35 2.28 ANNUAL RUNOFF (INCHES) 26.17 18.26 30.99 10 PERCENT EXCEEDS 21 21 27 50 PERCENT EXCEEDS 14 8.5 13 90 PERCENT EXCEEDS 4.9 2.4 3.3 e Estimated 202 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA, PR--Continued O N D 2000 J F M A M J J A S 2001 1 2 5 10 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND 203 RIO DE BAYAMON BASIN 50047600 RIO DE BAYAMON NEAR AGUAS BUENAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°14'39", long 66°08'39", at bridge on Highway 156, and 2.9 mi (4.7 km) west of Aguas Buenas plaza. DRAINAGE AREA.--18.5 mi2 (47.9 km2). PERIOD OF RECORD.--Water years 1958-65, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 06... 1350 18 322 8.0 25.8 16 8.1 103 <10 500 850 130 29.7 FEB 08... 1230 19 297 7.8 23.2 6.9 8.3 101 <10 220 330 -- -- MAY 04... 0720 20 291 7.5 23.7 4.0 7.3 89 <10 E170 370 100 24.1 AUG 31... 0835 10 325 7.5 24.6 -- 6.9 86 <10 520 570 130 29.8 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 06... 13.1 14.9 .6 1.89 123 <1.0 10.4 19.9 E.1 30.1 194 9.66 <10 FEB 08... -- -- -- -- 107 -- -- -- -- -- -- -- <10 MAY 04... 10.8 18.5 .8 1.77 105 <1.0 8.5 20.0 E.1 23.2 170 9.32 <10 AUG 31... 13.0 16.1 .6 1.88 122 -- 12.2 23.2 E.1 27.7 197 5.36 12 NITRO- CHRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) OCT 06... <.01 .8 .05 -- <.20 -- -- <.020 <2 21.9 27 <.11 1 FEB 08... <.01 .6 <.01 -- .33 .95 4.2 <.020 -- -- -- -- -- MAY 04... <.01 .3 .01 .29 .30 .59 2.6 <.020 <2 19.4 27 <.11 <1 AUG 31... <.01 .7 .02 -- <.20 -- -- <.020 -- -- -- -- -- 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- DATE (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) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 06... <20.0 420 M 48 <.14 <2.6 <.43 <31 <.01 <16 <.02 FEB 08... -- -- -- -- -- -- -- -- -- -- -- MAY 04... <20.0 110 <1 32 <.01 <2.6 <.43 <31 <.01 <16 .03 AUG 31... -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 204 RIO DE BAYAMON BASIN 50047850 RIO BAYAMON NR BAYAMON, PR LOCATION.--Lat 18°20'08", long 66°08'13", Hydrologic Unit 21010005, on left bank, at rock quarry near Highway 174, 1.3 mi (2.1 km) south of colonia Santa Rosa and 4.7 mi (7.6 km) south of Bayamón. DRAINAGE AREA.--41.8 mi2 (108.3 km2). PERIOD OF RECORD.--September 1964 to October 1970, June 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 98 ft (30 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Diversion to the Guaynabo water treatment plant, for municipal supply, made upstream from station (at Represa de San Juan). Flow is regulated by storage and release of water at Lago de Cidra (capacity 5,220 acre-ft), 10.5 mi(16.9 km) upstream. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14 166 21 12 10 17 8.6 12 7.4 8.4 53 19 2 104 516 14 11 11 13 8.4 8.6 7.7 7.4 12 10 3 60 383 13 14 9.7 8.6 8.6 7.5 7.1 7.5 8.1 12 4 15 74 13 12 9.2 8.5 12 7.2 11 8.7 7.4 15 5 12 32 13 12 9.1 8.3 10 6.8 8.5 8.0 6.7 9.9 6 12 24 12 11 8.9 8.1 16 16 6.9 6.7 34 8.8 7 18 21 12 11 8.9 8.1 12 169 6.4 7.1 12 8.5 8 17 20 12 11 8.8 7.9 8.8 65 6.2 12 9.1 8.2 9 14 19 12 11 9.0 7.9 8.5 42 5.9 6.1 9.0 8.1 10 12 18 13 10 9.1 7.8 7.8 18 5.8 13 12 8.3 11 11 17 12 10 24 7.9 11 15 5.4 12 12 8.3 12 11 16 13 11 11 7.8 8.1 9.5 5.2 11 10 8.0 13 10 15 16 10 10 8.6 8.3 8.7 5.0 20 9.2 8.2 14 10 17 16 12 9.6 8.7 8.4 8.1 5.0 19 8.8 7.7 15 9.9 29 28 12 12 8.5 8.1 7.6 5.6 8.3 8.6 7.7 16 25 18 21 11 11 8.5 7.9 7.3 6.3 6.7 8.9 7.6 17 12 16 47 13 10 8.2 7.6 7.3 7.7 6.4 22 7.6 18 10 15 30 11 10 8.1 7.6 8.0 6.7 8.4 17 7.5 19 19 15 20 11 10 8.0 7.6 9.0 5.6 12 11 7.4 20 13 17 20 11 11 8.6 8.2 7.2 5.4 7.2 9.4 e7.4 21 29 23 16 11 11 9.5 31 6.6 5.4 6.9 8.3 e7.3 22 74 20 14 12 104 9.4 49 6.3 5.8 62 11 e7.3 23 89 16 14 12 18 9.8 91 6.4 65 11 282 7.2 24 41 20 13 11 23 9.0 31 6.1 8.9 8.8 23 7.1 25 18 18 13 11 38 8.6 11 6.1 10 8.2 9.6 7.2 26 14 21 13 11 19 7.8 9.6 6.1 7.6 12 8.2 7.5 27 13 17 12 15 9.7 7.7 e8.9 6.0 8.9 8.5 20 15 28 17 15 12 28 8.6 7.6 9.1 6.2 11 7.7 18 9.8 29 16 14 12 95 --- 7.8 9.2 5.8 7.4 111 27 8.1 30 13 19 12 163 --- 8.2 8.1 15 8.0 21 11 7.8 31 13 --- 12 12 --- 8.2 --- 8.1 --- 12 9.0 --- TOTAL 745.9 1631 501 608 443.6 271.7 441.4 518.5 268.8 465.0 707.3 269.5 MEAN 24.1 54.4 16.2 19.6 15.8 8.76 14.7 16.7 8.96 15.0 22.8 8.98 MAX 104 516 47 163 104 17 91 169 65 111 282 19 MIN 9.9 14 12 10 8.6 7.6 7.6 5.8 5.0 6.1 6.7 7.1 AC-FT 1480 3240 994 1210 880 539 876 1030 533 922 1400 535 CFSM .58 1.30 .39 .47 .38 .21 .35 .40 .21 .36 .55 .21 IN. .66 1.45 .45 .54 .39 .24 .39 .46 .24 .41 .63 .24 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1964 - 2001, BY WATER YEAR (WY) MEAN 40.4 55.6 54.8 37.6 23.5 17.5 19.4 34.5 19.8 23.1 43.9 63.1 MAX 129 232 263 159 75.3 52.9 72.7 131 60.8 79.2 137 360 (WY) 1991 2000 1966 1969 1989 1990 1971 1966 1970 1999 1970 1996 MIN 4.30 7.91 3.45 5.30 4.75 3.58 5.36 4.85 3.68 4.01 7.47 6.02 (WY) 1969 1965 1998 1968 1965 1965 1965 1994 1994 1994 1994 1967 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1964 - 2001 ANNUAL TOTAL 12189.0 6871.7 ANNUAL MEAN 33.3 18.8 36.2 HIGHEST ANNUAL MEAN 69.5 1999 LOWEST ANNUAL MEAN 10.9 1994 HIGHEST DAILY MEAN 2320 Aug 23 516 Nov 2 8640 Sep 10 1996 LOWEST DAILY MEAN 4.7 Aug 21 5.0 Jun 13 2.2 Apr 19 1965 ANNUAL SEVEN-DAY MINIMUM 5.5 Aug 15 5.4 Jun 9 2.4 Apr 14 1965 MAXIMUM PEAK FLOW 3650 Nov 2 65000 Sep 10 1996 MAXIMUM PEAK STAGE 9.99 Nov 2 29.07 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 24180 13630 26200 ANNUAL RUNOFF (CFSM) .80 .45 .87 ANNUAL RUNOFF (INCHES) 10.85 6.12 11.76 10 PERCENT EXCEEDS 47 24 62 50 PERCENT EXCEEDS 14 11 13 90 PERCENT EXCEEDS 7.9 7.2 5.2 e Estimated 205 RIO DE BAYAMON BASIN 50047850 RIO BAYAMON NR BAYAMON, PR--Continued O N D 2000 J F M A M J J A S 2001 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 206 RIO DE BAYAMON BASIN 50047990 RIO GUAYNABO NEAR BAYAMON, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°22'32", long 66°07'59", at bridge on Highway 833, 0.2 mi (0.3 km) upstream from Río de Bayamón, and 2.3 mi (3.7 km) southeast of Bayamón plaza. DRAINAGE AREA.--73.2 mi2 (189.6 km2). PERIOD OF RECORD.--Water years 1958, 1964, 1971-73, 1976, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 PH OXYGEN, OXYGEN COLI- FECAL SPE- WATER DIS- DEMAND, FORM, STREP, HARD- MAGNE- CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM SIUM, CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- DIS- DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED SOLVED DATE TIME ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L (MG/L (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) AS MG) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) (00925) OCT 13... 0900 516 7.8 26.4 6.5 4.6 57 10 3900 760 170 46.9 12.8 FEB 23... 1345 438 7.6 24.9 85 6.7 80 12 E60000 810 -- -- -- MAY 30... 1330 209 7.5 28.5 -- 5.5 70 16 5900 2200 110 30.7 7.52 AUG 23... 1430 344 7.4 29.5 -- 5.8 76 15 2300 E17000 120 34.6 9.21 ANC SOLIDS, RESIDUE SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF TOTAL NITRO- NITRO- SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- AT 105 GEN, GEN, DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, DEG. C, NITRATE NITRITE SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- SUS- TOTAL TOTAL DATE (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PENDED (MG/L (MG/L AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) (MG/L) AS N) AS N) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (00530) (00620) (00615) OCT 13... 26.9 .9 2.79 175 <1.0 16.6 27.8 E.1 29.3 268 19 .72 .03 FEB 23... -- -- -- 154 -- -- -- -- -- -- 142 .96 .03 MAY 30... 17.3 .7 2.19 112 <1.0 9.3 21.0 E.1 17.8 173 18 .33 .02 AUG 23... 16.2 .6 2.87 120 -- 18.9 19.3 E.1 21.0 194 136 .96 .04 NITRO- CHRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 13... .8 .24 .04 .28 1.0 4.6 .160 <2 118 41 <.11 M <20.0 FEB 23... 1.0 .08 .87 .95 1.9 8.6 .360 -- -- -- -- -- -- MAY 30... .3 .07 .42 .49 .84 3.7 .120 <2 75.1 29 <.10 M <20.0 AUG 23... 1.0 .15 .68 .83 1.8 8.1 .260 -- -- -- -- -- -- MANGA- METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 13... 1030 M 229 <.14 <2.6 <.43 E18 E.01 <16 .06 FEB 23... -- -- -- -- -- -- -- -- -- -- MAY 30... 590 1 134 .01 <3.0 <.40 E16 <.01 E10 .10 AUG 23... -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 207 RIO DE BAYAMON BASIN 50048510 RIO DE BAYAMON AT FLOOD CHANNEL AT BAYAMON, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'29", long 66°09'04", at bridge on Highway 890, 1.0 mi (1.6 km) downstream from bridge on Highway 2, and 3.2 mi (5.1 km) above mouth. DRAINAGE AREA.--71.9 mi2 (186.2 km2). PERIOD OF RECORD.--Water years 1974 to current year. REMARKS.--Prior to 1979 sampling site was 0.8 mile (1.3 km) downstream but was changed because of flood channel construction. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 23... 1000 120 330 7.9 26.2 1.4 6.6 81 15 53000 29000 120 32.7 FEB 23... 1100 63 345 7.6 24.9 45 7.7 93 14 E60000 620 -- -- MAY 30... 1145 52 395 7.6 29.3 -- 7.9 102 <10 4300 470 150 39.6 SEP 07... 1045 36 485 7.6 28.5 -- 7.8 100 <10 <1000 <27 170 45.3 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 23... 10.1 16.8 .7 2.79 118 <1.0 15.5 17.2 .2 21.1 187 60.5 98 FEB 23... -- -- -- -- 126 -- -- -- -- -- -- -- 35 MAY 30... 12.3 22.5 .8 2.22 154 <1.0 13.1 28.8 .2 24.4 236 32.8 <10 SEP 07... 14.6 24.8 .8 2.17 169 -- 16.7 30.7 E.1 26.5 262 25.5 22 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) OCT 23... 1.15 .05 1.2 .34 .76 1.1 2.3 10.2 .200 <2 87.6 35 <.11 FEB 23... .69 .03 .7 .22 .26 .48 1.2 5.3 .140 -- -- -- -- MAY 30... -- <.01 .1 .02 .34 .36 .51 2.3 .040 M 64.7 37 <.10 SEP 07... .45 .02 .5 .10 .14 .24 .71 3.1 .060 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 23... 2 E18.2 3990 2 213 <.14 <2.6 <.43 E20 <.01 <16 <.08 FEB 23... -- -- -- -- -- -- -- -- -- -- -- -- MAY 30... <1 <20.0 260 <1 113 <.01 <3.0 <.40 <31 <.01 E5 .05 SEP 07... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 208 RIO DE BAYAMON BASIN 50048510 RIO DE BAYAMON AT FLOOD CHANNEL AT BAYAMON, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 CHLOR- DANE, P,P'- P,P'- ENDO- ENDRIN TECH- DDD P,P'- DDT DI- DI- SULFAN WATER HEPTA- PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I UNFLTRD ETHION, CHLOR, DATE TIME TOTAL TOTAL TOTAL RECOVER TOTAL RECOVER TOTAL TOTAL TOTAL REC TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39516) (39330) (39350) (39360) (39365) (39370) (39570) (39380) (39388) (39390) (39398) (39410) MAY 30... 1145 <.1 <.013 <.1 <.007 <.006 <.009 .04 <.006 <.015 <.014 <.01 <.014 CARBO- HEPTA- METH- METHYL PHENO- CHLOR MALA- OXY- PARA- PARA- TOX- THION EPOXIDE LINDANE THION, CHLOR, THION, MIREX, THION, APHENE, WATER 2,4-D, 2,4,5-T 2,4-DP SILVEX, DATE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL UNFLTRD TOTAL TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39420) (39340) (39530) (39480) (39600) (39755) (39540) (39400) (39786) (39730) (39740) (82183) (39760) MAY 30... <.009 <.006 1.76 <.01 <.01 <.01 <.01 <1 <.02 .06 <.01 <.04 <.01 209 RIO PUERTO NUEVO BASIN 50048680 LAGO LAS CURIAS AT DAMSITE NEAR RIO PIEDRAS, PR LOCATION.--Lat 18°20'40", long 66°03'03", Hydrologic Unit 21010005 at Lago Las Curias Dam on Río Piedras, 4.2 mi (6.7 km) south of University of Puerto Rico Tower, 1.6 mi (2.6 km) northwest from Escuela José F. Díaz and 0.8 mi (1.3 km) north of Escuela Cupey Alto. DRAINAGE AREA.--0.97 mi2 (2.51 km2). ELEVATION RECORDS PERIOD OF RECORD.--April 1997 to current year. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Las Curias was completed in 1946. The reservoir has a capacity of 1,135 ac-ft (1.40 hm3) at spillway crest elevation 315.78 ft (96.25 m) for water supply. The dam is earthfill and has a crest elevation of 327.3 ft (99.75 m). Masonry parapet walls continous from abutment on each side of the 25 ft (7.62 m) wide crest. The dam is about 82.0 ft (25.0 m) high and 984.2 ft (300.0 m) long. The morning-glory inlet conduit spillway in located along the left abutment of the dam and has an uncontrolled capacity of about 5,000 ft3/s (141.6 m3/s) at reservoir elevation 321.5 ft (98.0 m). This dam is operated by Puerto Rico Aqueduct and Sewer Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 317.01 ft (96.62 m),Aug. 11, 1998; minimum elevation, 313.04 ft (95.41 m), Oct. 5, 1998. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 316.71 ft (96.53 m), Oct. 22; minimum elevation, 315.66 ft (96.21 m), June 15. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 284.7 154 313.0 677 298.2 462 314.3 1,078 307.1 770 317.5 1,232 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 315.85 315.92 315.82 315.81 315.82 315.83 315.73 315.79 315.77 315.88 315.82 315.82 2 315.84 315.97 315.81 315.82 315.82 315.82 315.72 315.76 315.76 315.85 315.82 315.81 3 315.83 315.88 315.81 315.84 315.81 315.82 315.73 315.75 315.75 315.82 315.88 315.83 4 315.81 315.86 315.81 315.83 315.81 315.81 315.91 315.71 315.75 315.86 315.82 315.81 5 315.81 315.86 315.81 315.83 315.81 315.80 315.82 315.70 315.78 315.83 315.81 315.83 6 315.81 315.86 A 315.82 315.81 315.80 315.81 315.79 315.77 315.82 315.82 315.84 7 315.82 315.85 315.80 315.82 315.81 315.80 315.80 315.79 315.76 315.81 315.81 315.83 8 315.81 315.85 315.81 315.82 315.81 315.80 315.80 315.87 315.75 315.80 315.80 315.83 9 315.80 315.85 315.81 315.82 315.80 315.80 315.80 315.80 315.73 315.79 315.79 315.83 10 315.79 315.86 315.83 315.81 315.83 315.78 315.79 315.89 315.72 315.79 315.83 315.83 11 315.91 315.85 315.82 315.82 315.84 315.77 315.80 315.79 315.70 315.79 315.83 315.83 12 315.82 315.85 315.81 315.82 315.83 315.76 315.78 315.77 315.70 315.84 315.81 315.81 13 315.80 315.85 315.81 315.81 315.81 315.83 315.78 315.76 315.69 315.81 315.80 315.80 14 315.80 315.86 315.82 315.85 315.81 315.81 315.78 315.75 315.67 315.86 315.79 315.79 15 315.80 315.85 315.82 315.84 315.82 315.80 315.77 315.75 315.69 315.81 315.78 315.80 16 315.84 315.83 315.84 315.94 315.83 315.79 315.76 315.75 315.69 315.80 315.77 315.79 17 315.81 315.83 A 315.84 315.83 315.78 315.74 315.74 315.80 315.79 315.83 315.86 18 315.81 315.83 A 315.83 315.82 315.78 315.73 315.77 315.85 315.79 315.81 315.83 19 315.83 315.83 A 315.83 315.82 315.78 315.71 315.79 315.82 315.78 315.82 315.82 20 315.81 315.83 A 315.83 315.82 315.82 315.70 315.78 315.81 315.78 315.80 315.82 21 315.82 315.83 315.84 315.82 315.82 315.84 315.75 315.78 315.80 315.78 315.79 315.82 22 315.89 315.83 315.83 315.82 315.84 315.84 315.78 315.78 315.80 315.77 316.04 315.82 23 315.90 315.83 315.83 315.81 315.86 315.82 315.78 315.78 315.86 315.82 315.84 315.81 24 315.87 315.82 315.83 315.81 315.89 315.85 315.82 315.77 315.85 315.79 315.84 315.81 25 315.85 315.82 315.83 315.81 315.84 315.80 315.80 315.76 315.83 315.79 315.83 315.80 26 315.84 315.84 315.83 315.81 315.83 315.79 315.85 315.75 315.81 315.79 315.82 315.80 27 315.85 315.82 315.82 315.90 315.83 315.78 A 315.75 315.81 315.78 315.82 315.80 28 315.89 315.84 315.82 315.84 315.83 315.77 315.77 315.75 315.88 315.78 315.82 315.79 29 315.85 315.82 315.82 315.90 --- 315.77 315.77 315.74 315.84 315.90 315.86 315.78 30 315.85 315.83 315.82 315.84 --- 315.76 315.76 315.74 315.90 315.83 315.81 315.77 31 315.85 --- 315.81 315.82 --- 315.75 --- 315.74 --- 315.82 315.80 --- MAX 315.91 315.97 --- 315.94 315.89 315.85 --- 315.89 315.90 315.90 316.04 315.86 MIN 315.79 315.82 --- 315.81 315.80 315.75 --- 315.70 315.67 315.77 315.77 315.77 A No gage-height record 210 RIO PUERTO NUEVO BASIN 50048680 LAGO LAS CURIAS AT DAMSITE NEAR RIO PIEDRAS, PR--Continued O N D 2000 J F M A M J J A S 2001 315.65 315.7 315.75 315.8 315.85 315.9 315.95 316 316.05 ELEVATION, IN FEET Gap indicates missing record 211 RIO PUERTO NUEVO BASIN 50048690 QUEBRADA LAS CURIAS BELOW LAS CURIAS DAM, PR LOCATION.--Lat 18°20'44", long 66°03'15", Hydrologic Unit 21010005, at 0.2 miles (0.3 km) from Lago Las Curias Dam on Río Piedras, 4.1 mi (6.6 km) south of University of Puerto Rico Tower, 2.6 mi (4.1 km) northwest from Lago Loíza spillway crest and 0.8 mi (1.37 km) north of Escuela Cupey Alto. DRAINAGE AREA.--1.08 mi2 (2.79 km2). PERIOD OF RECORD.--August 1997 to current year. GAGE.--Water stage recorder. Elevation of gage is 262.47 ft (80.0 km), from topographic map. REMARKS.--Records poor. Flow completly regulated by Lago Las Curías Dam, 0.20 mi (0.32 km) from gage. Gage-height and precipitation satellite telemetry at station.. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2.4 25 1.3 .45 .74 .40 .31 1.2 .28 6.2 1.6 .67 2 2.6 24 1.2 .40 .89 .52 .20 1.0 .36 2.6 .65 .73 3 1.7 28 .90 2.7 .74 .51 .20 .35 .28 1.3 12 .79 4 .79 3.7 .71 1.2 .70 .47 23 1.0 .28 4.0 3.2 .96 5 .39 2.4 .68 .61 .47 .71 3.8 .34 .30 2.1 .91 .53 6 .29 2.1 .75 .69 .43 .29 .62 .34 .54 .58 .77 .62 7 .32 2.2 .81 .48 .37 .27 .57 7.5 .38 .55 .79 .57 8 .53 1.7 .78 .68 .70 .30 .33 11 .39 .44 .55 .39 9 .50 1.6 .75 .66 .88 .49 .54 3.8 .38 .40 .55 1.1 10 .29 1.3 1.2 .36 .79 .79 .36 18 .37 .36 .49 1.3 11 27 1.3 1.3 .33 4.8 .34 1.6 5.1 .28 .26 1.5 1.4 12 5.2 1.5 1.4 .38 1.8 .39 .60 1.2 .26 1.7 1.0 .68 13 1.0 1.6 1.7 .45 1.1 .63 .42 .65 .28 1.3 .69 .53 14 .57 1.9 1.5 .87 .70 1.4 .25 .52 .27 4.0 .45 .51 15 .46 2.7 3.3 1.3 1.2 .64 .23 .36 .28 1.7 .33 .36 16 4.8 2.2 2.7 7.6 1.0 .63 .49 .26 .29 .58 .48 .43 17 1.5 1.5 4.0 5.3 .78 .62 .41 .33 .38 .33 .74 2.9 18 .62 1.4 4.8 .99 .71 .32 .38 .33 1.7 .35 .91 2.0 19 1.7 1.5 e3.5 .71 .46 .29 .36 .87 1.3 .28 .56 1.1 20 1.3 1.5 e2.0 .57 .69 1.2 .27 .67 .59 .23 .80 .27 21 2.1 1.4 .87 .60 .52 1.7 .29 .28 .37 .26 .60 .35 22 33 1.4 1.2 .45 7.4 2.4 .35 .22 .35 .25 4.5 .36 23 27 1.9 .69 .80 2.8 1.4 .50 .27 3.0 .50 13 .30 24 17 1.2 .80 .42 3.0 4.9 1.7 .60 3.1 .85 1.6 .34 25 4.1 1.3 .74 .42 4.0 2.1 1.1 .40 2.0 .32 1.2 .35 26 1.4 1.8 .47 .30 1.0 .79 10 .30 .97 .31 .65 .31 27 1.2 1.8 .63 1.8 .44 .57 e2.7 .25 .46 .36 .65 .25 28 12 1.4 .51 4.3 .40 .27 .63 .37 10 .31 .73 .32 29 3.8 1.4 .53 8.3 --- .31 .27 .28 2.1 19 .95 .38 30 2.2 1.3 .75 4.7 --- .30 .50 .24 11 4.0 2.5 .32 31 1.8 --- .60 1.1 --- .35 --- .35 --- 1.7 .57 --- TOTAL 159.56 124.0 43.07 49.92 39.51 26.30 52.98 58.38 42.54 57.12 55.92 21.12 MEAN 5.15 4.13 1.39 1.61 1.41 .85 1.77 1.88 1.42 1.84 1.80 .70 MAX 33 28 4.8 8.3 7.4 4.9 23 18 11 19 13 2.9 MIN .29 1.2 .47 .30 .37 .27 .20 .22 .26 .23 .33 .25 AC-FT 316 246 85 99 78 52 105 116 84 113 111 42 CFSM 4.77 3.83 1.29 1.49 1.31 .79 1.64 1.74 1.31 1.71 1.67 .65 IN. 5.50 4.27 1.48 1.72 1.36 .91 1.82 2.01 1.47 1.97 1.93 .73 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1997 - 2001, BY WATER YEAR (WY) MEAN 4.87 5.86 4.74 2.47 1.67 1.09 1.11 1.07 1.67 1.68 3.54 3.89 MAX 5.90 11.4 10.2 4.63 2.51 2.52 1.77 1.88 3.64 3.51 7.06 12.2 (WY) 1999 2000 1999 1999 1999 1999 2001 2001 1999 1999 1998 1998 MIN 3.46 .92 .51 .83 1.16 .33 .63 .29 .52 .33 1.80 .70 (WY) 1998 1998 1998 1998 2000 1998 2000 1998 1998 2000 2001 2001 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1997 - 2001 ANNUAL TOTAL 742.40 730.42 ANNUAL MEAN 2.03 2.00 2.87 HIGHEST ANNUAL MEAN 3.95 1999 LOWEST ANNUAL MEAN 2.00 2001 HIGHEST DAILY MEAN 66 Aug 23 33 Oct 22 96 Sep 22 1998 LOWEST DAILY MEAN .22 Jul 13 .20 Apr 2 .17 Oct 7 1998 ANNUAL SEVEN-DAY MINIMUM .24 Aug 9 .28 Mar 28 .19 Jun 26 1998 MAXIMUM PEAK FLOW 261 Oct 22 431 Aug 11 1998 MAXIMUM PEAK STAGE 10.66 Oct 22 11.70 Aug 11 1998 ANNUAL RUNOFF (AC-FT) 1470 1450 2080 ANNUAL RUNOFF (CFSM) 1.88 1.85 2.66 ANNUAL RUNOFF (INCHES) 25.57 25.16 36.11 10 PERCENT EXCEEDS 3.3 4.0 7.2 50 PERCENT EXCEEDS .68 .71 .76 90 PERCENT EXCEEDS .28 .30 .29 e Estimated 212 RIO PUERTO NUEVO BASIN 50048690 QUEBRADA LAS CURIAS BELOW LAS CURIAS DAM, PR--Continued O N D 2000 J F M A M J J A S 2001 0.1 0.2 0.5 1 2 5 10 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND 213 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR LOCATION.--Lat 18°21'51", long 66°03'56", Hydrologic Unit 21010005, on right bank, in the Riberas of Señorial Housing area, 0.6 mi (1.0 km) west of Highway 176 and 2.7 mi (4.3 km) southwest of Río Piedras Plaza. DRAINAGE AREA.--7.49 mi2 (19.40 km2). WATER DISCHARGE RECORDS PERIOD OF RECORDS.--March 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 98.4 ft (30.0 m), from topographic map. REMARKS.--Records poor. Low flow is affected by discharges from water treatment plant of PRASA and others dispersed pollution points directly to the river. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14 106 11 7.7 9.0 8.6 6.3 23 13 64 24 46 2 30 160 e10 7.8 9.4 9.2 6.0 7.9 8.1 27 12 14 3 25 182 e9.1 24 8.3 9.7 9.1 6.2 5.5 13 67 18 4 11 32 e12 8.5 8.3 8.2 165 8.5 6.1 60 22 15 5 9.0 20 9.2 8.0 7.9 8.5 23 5.8 24 15 14 12 6 8.3 16 9.0 7.8 7.7 8.1 8.0 39 8.4 9.2 24 9.2 7 10 14 8.8 7.8 7.6 8.2 7.5 78 5.5 8.1 12 8.6 8 9.3 13 10 8.0 8.1 9.2 6.4 119 5.4 7.6 9.5 8.1 9 8.5 e14 8.3 7.6 7.6 8.1 8.9 30 5.2 7.1 10 20 10 7.9 e12 8.1 7.4 13 7.8 6.1 156 5.1 9.3 56 26 11 102 e14 8.6 7.3 63 7.0 25 33 5.0 17 51 13 12 18 11 10 6.9 14 7.1 7.0 12 5.0 33 20 8.8 13 9.1 12 e12 7.0 11 25 e8.2 9.2 5.3 9.4 13 8.3 14 9.2 13 e11 10 8.9 9.0 6.5 7.9 5.0 64 13 8.1 15 7.6 24 e29 8.0 18 8.3 8.0 7.8 5.4 12 12 10 16 32 14 24 69 9.9 8.3 6.6 6.7 7.0 9.9 12 9.9 17 10 e12 33 31 8.7 7.4 5.7 6.5 20 7.9 28 68 18 8.6 12 28 9.3 7.6 7.1 5.8 12 37 9.3 16 17 19 14 e13 e22 8.7 8.1 7.1 7.0 8.7 7.3 8.3 27 9.5 20 17 14 e11 8.6 7.8 25 5.7 7.6 6.0 8.1 14 7.2 21 48 13 9.1 7.8 7.8 16 21 7.0 5.5 7.0 11 7.1 22 218 11 11 8.2 65 29 18 8.1 5.3 7.0 78 6.7 23 153 14 8.3 8.4 25 9.5 8.6 6.3 119 35 102 6.6 24 142 11 8.1 7.6 31 20 32 7.1 40 8.6 22 6.7 25 34 12 8.1 7.5 23 9.6 12 6.6 20 7.3 13 6.4 26 17 18 8.1 7.3 17 6.9 105 6.1 8.9 8.1 11 6.4 27 21 e12 8.3 30 8.9 11 15 6.2 8.5 7.5 14 8.6 28 78 e13 8.2 25 10 12 7.8 6.6 194 6.9 14 6.9 29 21 11 e7.4 83 --- 12 8.2 5.7 21 192 16 6.6 30 17 12 7.6 23 --- 7.1 6.6 15 102 35 34 6.4 31 14 --- 7.8 9.5 --- 6.5 --- 8.1 --- 39 12 --- TOTAL 1123.5 835 376.1 477.7 431.6 336.5 566.0 667.6 713.5 752.6 783.5 405.1 MEAN 36.2 27.8 12.1 15.4 15.4 10.9 18.9 21.5 23.8 24.3 25.3 13.5 MAX 218 182 33 83 65 29 165 156 194 192 102 68 MIN 7.6 11 7.4 6.9 7.6 6.5 5.7 5.7 5.0 6.9 9.5 6.4 AC-FT 2230 1660 746 948 856 667 1120 1320 1420 1490 1550 804 CFSM 4.84 3.72 1.62 2.06 2.06 1.45 2.52 2.88 3.18 3.24 3.37 1.80 IN. 5.58 4.15 1.87 2.37 2.14 1.67 2.81 3.32 3.54 3.74 3.89 2.01 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1988 - 2001, BY WATER YEAR (WY) MEAN 27.9 27.2 20.5 16.3 13.2 11.4 11.9 14.7 13.2 15.5 23.0 30.2 MAX 57.3 79.5 66.3 29.1 23.6 20.1 23.9 47.2 25.5 38.0 66.9 80.8 (WY) 1991 2000 1999 2000 1991 1999 1993 1992 1999 1993 1992 1998 MIN 8.48 5.93 4.32 6.95 2.70 1.85 2.83 3.38 2.66 4.22 6.60 6.90 (WY) 1992 1996 1996 1995 1996 1996 1995 1994 1994 1994 1990 1991 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1988 - 2001 ANNUAL TOTAL 7268.5 7468.7 ANNUAL MEAN 19.9 20.5 18.6 HIGHEST ANNUAL MEAN 28.6 1999 LOWEST ANNUAL MEAN 7.76 1994 HIGHEST DAILY MEAN 646 Aug 23 218 Oct 22 1650 Sep 10 1996 LOWEST DAILY MEAN 4.2 Aug 13 5.0 Jun 11 .84 Aug 13 1995 ANNUAL SEVEN-DAY MINIMUM 4.8 Aug 8 5.1 Jun 8 .97 Jun 30 1996 MAXIMUM PEAK FLOW 2550 Oct 22 5390 Sep 10 1996 MAXIMUM PEAK STAGE 12.10 Oct 22 15.46 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 14420 14810 13500 ANNUAL RUNOFF (CFSM) 2.65 2.73 2.49 ANNUAL RUNOFF (INCHES) 36.10 37.09 33.82 10 PERCENT EXCEEDS 32 36 38 50 PERCENT EXCEEDS 10 9.5 8.4 90 PERCENT EXCEEDS 5.4 6.6 3.0 e Estimated 214 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR--Continued O N D 2000 J F M A M J J A S 2001 1 2 5 10 10 20 50 100 100 200 500 1000 DISCHARGE, IN CUBIC FEET PER SECOND 215 RIO PUERTO NUEVO BASIN 50048800 RIO PIEDRAS NEAR RIO PIEDRAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°22'15", long 66°03'40", at bridge on Winston Churchill Avenue in the El Señorial Housing area, 0.5 mi (0.8 km) west of Highway 176, and 2.5 mi (4.0 km) southwest of Río Piedras plaza. DRAINAGE AREA.--8.17 mi2 (20.9 km2). PERIOD OF RECORD.--Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DIS- PH OXYGEN, OXYGEN COLI- FECAL CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP, HARD- INST. CIFIC WHOLE SOLVED CHEM- FECAL, KF STRP NESS CALCIUM CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 MF, TOTAL DIS- FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF WATER (MG/L SOLVED DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ (COL/ AS (MG/L SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) AS CA) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31625) (31673) (00900) (00915) OCT 18... 1030 8.8 435 8.1 25.3 3.0 8.1 98 13 5200 E1500 150 40.4 FEB 21... 1130 6.9 423 8.0 24.2 2.6 9.3 110 <10 21000 4000 -- -- MAY 31... 1335 6.2 377 8.0 28.5 -- 7.1 91 18 5800 3200 140 36.4 AUG 29... 1300 9.3 488 7.7 28.5 -- 7.3 93 <10 3200 450 160 42.6 ANC SOLIDS, RESIDUE MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI- DIS- AT 105 DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS- (TONS SUS- DATE (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED PER PENDED AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) (70302) (00530) OCT 18... 13.0 25.5 .9 2.35 153 <1.0 15.9 31.9 E.2 33.3 254 6.06 <10 FEB 21... -- -- -- -- 159 -- -- -- -- -- -- -- <10 MAY 31... 11.3 22.3 .8 2.39 133 <1.0 13.4 27.8 .2 28.0 221 3.68 17 AUG 29... 13.6 26.2 .9 2.08 156 -- 16.7 32.6 .2 32.3 260 6.54 180 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) OCT 18... .83 .02 .8 .07 .29 .36 1.2 5.4 .080 <2 107 34 <.11 FEB 21... .86 .04 .9 .25 .18 .43 1.3 5.9 .120 -- -- -- -- MAY 31... .70 .09 .8 .17 .47 .64 1.4 6.3 .120 E1 91.9 32 <.10 AUG 29... .78 .01 .8 .04 -- <.20 -- -- .170 -- -- -- -- CHRO- MANGA- METHY- MIUM, COPPER, IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01034) (01042) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 18... M <20.0 260 <1 54 <.14 <2.6 <.43 <31 <.01 <16 .06 FEB 21... -- -- -- -- -- -- -- -- -- -- -- -- MAY 31... M <20.0 710 <1 211 .01 <3.0 <.40 <31 <.01 E3 .03 AUG 29... -- -- -- -- -- -- -- -- -- -- -- -- E -- Estimated value < -- Less than M -- Presence verified, not quantified 216 RIO PUERTO NUEVO BASIN 50048800 RIO PIEDRAS NEAR RIO PIEDRAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 CHLOR- DANE, P,P'- P,P'- ENDO- ENDRIN TECH- DDD P,P'- DDT DI- DI- SULFAN WATER HEPTA- PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I UNFLTRD ETHION, CHLOR, DATE TIME TOTAL TOTAL TOTAL RECOVER TOTAL RECOVER TOTAL TOTAL TOTAL REC TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39516) (39330) (39350) (39360) (39365) (39370) (39570) (39380) (39388) (39390) (39398) (39410) MAY 31... 1335 <.1 <.013 <.1 <.007 <.006 <.009 .13 <.006 <.015 <.014 <.01 <.014 CARBO- HEPTA- METH- METHYL PHENO- CHLOR MALA- OXY- PARA- PARA- TOX- THION EPOXIDE LINDANE THION, CHLOR, THION, MIREX, THION, APHENE, WATER 2,4-D, 2,4,5-T 2,4-DP SILVEX, DATE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL UNFLTRD TOTAL TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39420) (39340) (39530) (39480) (39600) (39755) (39540) (39400) (39786) (39730) (39740) (82183) (39760) MAY 31... <.009 <.006 E.01 <.01 <.01 <.01 <.01 <1 <.01 .09 <.01 <.04 <.01 217 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR LOCATION.--Lat 18°24'34", long 66°04'10", Hydrologic Unit 21010005, at bridge on Avenida Piñeiro near Expreso Las Américas (Luis A. Ferré), and 0.8 mi (1.3 km) southwest of Hato Rey. DRAINAGE AREA.--15.2 mi2 (39.4 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--June 1970 to December 1987 (discharge measurements only), 1972 to December 1982 (maximum discharge only), January 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 16 ft (5 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Mean daily discharge affected by sewage discharges (approximately 2.0 ft3/s (0.06 m3/s)), 20 ft (6 m) upstream from gaging station. REVISIONS.--The peak discharges and annual maximum (*) reported for water years 1999 and 2000 have been revised as shown in the following table. They supersede figures published on those corresponding water years Data Reports. Water Discharge Gage height Year Date (ft3/s) (m3/s) (ft) (m) 1999 Dec. 3, 1999 *3,070 87.0 13.59 4.140 2000 Aug. 13, 2000 *6,120 173 18.05 4.502 DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 30 217 23 18 19 17 e14 50 23 63 46 51 2 52 344 22 19 21 18 e13 21 14 35 79 52 3 37 514 21 42 17 16 e20 18 12 25 65 27 4 25 47 23 18 17 16 e134 19 12 103 33 19 5 24 37 22 17 17 16 28 16 49 31 21 18 6 23 34 22 17 17 16 17 88 14 23 27 16 7 24 32 21 17 16 16 17 161 13 22 20 15 8 31 31 22 18 16 17 17 525 12 20 17 15 9 23 33 21 17 16 16 26 51 12 21 24 21 10 23 30 20 17 22 16 15 196 11 21 46 25 11 108 35 21 17 101 15 47 38 11 65 52 24 12 29 29 27 17 32 16 16 21 11 436 24 17 13 23 29 27 17 19 32 18 18 13 38 17 23 14 23 37 26 18 19 19 16 17 12 73 21 14 15 22 46 39 18 31 16 16 16 14 26 20 46 16 43 30 71 101 22 e17 16 15 14 23 15 16 17 24 25 65 47 17 e16 15 15 28 21 38 126 18 22 25 33 22 16 e15 15 23 28 21 169 22 19 28 26 31 21 15 e15 16 19 15 20 29 17 20 26 32 23 19 20 e35 16 14 13 20 18 15 21 50 29 20 18 38 e28 40 14 12 19 15 28 22 266 36 23 18 106 e38 34 16 11 22 206 33 23 158 35 19 18 50 e19 29 14 101 40 176 68 24 268 28 19 17 63 e30 100 14 33 24 25 114 25 65 40 19 17 29 e19 56 14 42 20 22 21 26 49 33 19 16 26 e15 378 13 14 32 18 18 27 190 25 19 27 18 e25 e44 18 15 18 19 28 28 129 34 19 43 18 e26 e24 17 233 17 33 17 29 49 24 e17 100 --- e26 22 12 37 527 18 16 30 52 24 18 30 --- e17 23 33 107 59 50 15 31 49 --- 18 18 --- e14 --- 15 --- 57 17 --- TOTAL 1965 1941 790 819 818 617 1242 1521 936 1942 1380 937 MEAN 63.4 64.7 25.5 26.4 29.2 19.9 41.4 49.1 31.2 62.6 44.5 31.2 MAX 268 514 71 101 106 38 378 525 233 527 206 126 MIN 22 24 17 16 15 14 13 12 11 17 15 14 AC-FT 3900 3850 1570 1620 1620 1220 2460 3020 1860 3850 2740 1860 CFSM 4.17 4.26 1.68 1.74 1.92 1.31 2.72 3.23 2.05 4.12 2.93 2.05 IN. 4.81 4.75 1.93 2.00 2.00 1.51 3.04 3.72 2.29 4.75 3.38 2.29 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1972 - 2001, BY WATER YEAR (WY) MEAN 70.4 74.0 52.3 44.8 40.6 35.5 48.8 43.3 39.7 47.5 57.7 90.5 MAX 138 235 168 97.4 86.9 78.5 150 97.5 81.9 97.4 91.0 261 (WY) 1999 1993 1993 1993 1995 1972 1972 1992 1995 1993 2000 1996 MIN 16.6 23.9 18.8 12.9 10.8 11.5 13.6 4.12 19.6 12.8 20.2 26.3 (WY) 1992 1991 1992 1973 1992 1994 1995 1972 2000 1994 1993 1972 SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1972 - 2001 ANNUAL TOTAL 15378 14908 ANNUAL MEAN 42.0 40.8 53.0 HIGHEST ANNUAL MEAN 84.0 1993 LOWEST ANNUAL MEAN 28.7 1994 HIGHEST DAILY MEAN 1640 Aug 23 527 Jul 29 4550 Sep 10 1996 LOWEST DAILY MEAN 12 Jun 10 11 Jun 10 1.2 Jun