Southern Puerto Rico HUC8 21010004
A 3,494 km² sub-basin of the Caribbean region in PR. Drought coverage is from the US Drought Monitor (map of 2026-09-01); streamflow classes place each USGS gauge's latest reading against its own day-of-year record.
Health score
48
Stressed
Drought index
375
Extreme
Area in D2+
89.72%
0% exceptional (D4)
Gauges below normal
41%
of 34 reporting
Median flow
104%
p52 of record
Water assets
13
2 springs · 0 wells
USGS gauges (38)
- RIO GUAYANILLA NEAR GUAYANILLA, PR501242002 cfsp4 · much below normal
- RIO YAUCO ABV DIVERSION MONSERRATE NR YAUCO, PR501261501 cfsp5 · much below normal
- RIO JACAGUAS ABV LAGO GUAYABAL5011065010 cfsp5 · much below normal
- RIO GRANDE DE PATILLAS NR PATILLAS, PR500920008 cfsp6 · much below normal
- RIO PORTUGUES NR TIBES, PR501149005 cfsp7 · much below normal
- RIO LAPA NR RABO DEL BUEY, PR501002000 cfsp7 · much below normal
- RIO CERRILLOS ABV LAGO CERRILLOS NR PONCE, PR5011380010 cfsp7 · much below normal
- RIO GRANDE DE PATILLAS BLW LAGO PATILLAS, PR500931200 cfsp10 · below normal
- RIO INABON AT REAL ABAJO, PR501125006 cfsp10 · below normal
- RIO MAJADA AT LA PLENA, PR501004500 cfsp16 · below normal
- RIO COAMO AT HWY 14 AT COAMO, PR501061004 cfsp17 · below normal
- RIO PORTUGUES AT PARQUE CEREMONIAL TIBES NR PONCE501152402 cfsp19 · below normal
- RIO TOA VACA ABV LAGO TOA VACA, PR501109004 cfsp20 · below normal
- RIO CERRILLOS BLW LAGO CERRILLOS NR PONCE, PR501140005 cfsp22 · below normal
- RIO JACAGUAS AT JUANA DIAZ, PR5011150010 cfsp26 · normal
- CANAL DE JUANA DIAZ AT BO. PENUELAS NR SALINAS, PR501113404 cfsp37 · normal
- CANAL DE JUANA DIAZ AT PASO SECO NR SANTA ISABEL5011133010 cfsp47 · normal
- CANAL DE RIEGO DE LAJAS AT BO. PALMAREJO NR LAJAS501289457 cfsp57 · normal
- CANAL DE JUANA DIAZ AT PIEDRA AGUZADA NR JUANA DIA5011132020 cfsp68 · normal
- CANAL DE PATILLAS ABV EL LEGADO INTAKE, PR5009309010 cfsp75 · above normal
- CANAL RIEGO DE LAJAS ABV LAJAS FILTRATION PLANT5012893318 cfsp76 · above normal
- CANAL DE RIEGO DE LAJAS ABV MAJINAS FILT. PLANT PR5012892030 cfsp76 · above normal
- CANAL DE PATILLAS BLW GUAYAMA FILTRATION PLANT, PR5009307814 cfsp77 · above normal
- CANAL DE GUAMANI OESTE AT HWY 15 GUAYAMA, PR500950006 cfsp77 · above normal
- CANAL DE RIEGO DE LAJAS BLW LAJAS FILT PLANT LAJAS5012894010 cfsp77 · above normal
- CANAL DE RIEGO DE LAJAS BLW MAJINAS FILT. PLANT PR5012892527 cfsp77 · above normal
- CANAL DE RIEGO DE LAJAS BLW LAGO LOCO DAM YAUCO PR5012890536 cfsp78 · above normal
- CANAL DE PATILLAS ABV GUAYAMA FILTRATION PLANT, PR5009307527 cfsp79 · above normal
- CANAL DE PATILLAS AT FOREBAY, PR5009305326 cfsp80 · above normal
- CANAL DE PATILLAS ABV AES INTAKE AT GUAYAMA, PR5009308316 cfsp82 · above normal
- CANAL DE PATILLAS AT INTAKE 123, SALINAS PR500931158 cfsp87 · above normal
- RIO MARIN NR PATILLAS, PR5009300054 cfsp88 · above normal
- CANAL DE PATILLAS AT INTAKE 113 SALINAS, PR500931107 cfsp88 · above normal
- LATERAL M5L, CANAL DE RIEGO DE LAJAS SABANA GRANDE501289072 cfsp98 · much above normal
- CANAL DE JUANA DIAZ AT LAGO GUAYABAL, PR18045506630170123 cfsno long-term record
- RIO ARROYATA AT HWY 7774 NR CIDRA, PR500439502 cfsno long-term record
- RIO COAMO NR COAMO, PR50106500101 cfsno long-term record
- RIO LOCO AT LAS LATAS NR LA JOYA NR GUANICA, PR501292540 cfsno long-term record
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-09-07 | 375 | 89.72 | 14/34 | p52 |
Top water assets
- 67Portugues Damreservoir
- 67Toa Vaca Damreservoir
- 67Guayabal Damreservoir
- 67Patillas Damreservoir
- 67Lucchetti Damreservoir
- 67Cerrillos Damreservoir
- 66Ana Mariaâ Ii Damreservoir
- 66Ana Mariaâ V Damreservoir
- 66Coamo Damreservoir
- 66Loco Damreservoir