Santa Ana HUC8 18070203
A 4,388 km² sub-basin of the California region in CA. 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
71
Moderate
Drought index
9
Abnormally dry
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
19%
of 27 reporting
Median flow
298%
p85 of record
Water assets
2,719
46 springs · 2,422 wells
USGS gauges (29)
- FONTANA PH FOREBAY SPILLWAY NR FONTANA CA110624500 cfsp10 · below normal
- FONTANA WATER CO SPILL CH FROM AFTERBAY NR FONTANA110628000 cfsp10 · below normal
- TEMESCAL C A CORONA LK NR CORONA CA110719000 cfsp10 · below normal
- SANTIAGO C A SANTA ANA CA110775000 cfsp10 · below normal
- SANTA ANA R A SANTA ANA CA110780000 cfsp10 · below normal
- TEMESCAL C AB MAIN ST A CORONA CA110721003 cfsp34 · normal
- CITY C NR HIGHLAND CA110558000 cfsp60 · normal
- FONTANA WATER CO SURFACE DIV NR FONTANA CA110624001 cfsp60 · normal
- WARM C NR SAN BERNARDINO CA110604003 cfsp69 · normal
- E TWIN C NR ARROWHEAD SPRINGS CA110585001 cfsp77 · above normal
- CAJON C BL LONE PINE C NR KEENBROOK CA110635106 cfsp80 · above normal
- WATERMAN CANYON CREEK NR ARROWHEAD SPRINGS CA110586001 cfsp83 · above normal
- CHINO C A SCHAEFER AVENUE NR CHINO CA110733603 cfsp84 · above normal
- SAN ANTONIO C A RIVERSIDE DRIVE NR CHINO CA110733001 cfsp85 · above normal
- SANTA ANA R A MWD CROSSING CA11066460137 cfsp86 · above normal
- CUCAMONGA C NR MIRA LOMA CA1107349569 cfsp87 · above normal
- SAR SUPP GAGE NR MENTONE CA1105150210 cfsp87 · above normal
- DEVIL CYN C NR SAN BERNARDINO CA110636801 cfsp87 · above normal
- SANTA ANA R BL PRADO DAM CA11074000268 cfsp88 · above normal
- CUCAMONGA C NR UPLAND CA110734709 cfsp90 · above normal
- SANTA ANA R NR MENTONE (RIVER ONLY) CA1105149926 cfsp95 · much above normal
- SANTA ANA R A E ST NR SAN BERNARDINO CA110593001 cfsp96 · much above normal
- SAN TIMOTEO C NR LOMA LINDA CA1105750017 cfsp99 · much above normal
- PLUNGE C NR EAST HIGHLANDS CA1105550013 cfsp100 · much above normal
- LYTLE C NR FONTANA CA1106200047 cfsp100 · much above normal
- FONTANA WATER CO SURFACE DIV WEIR 2 NR FONTANA CA110623991 cfsp100 · much above normal
- LYTLE C A COLTON CA110650006 cfsp100 · much above normal
- LYTLE C DIV TO FONTANA PH AVM NR FONTANA CA1106270012 cfsno long-term record
- COLDWATER CANYON C NR CORONA CA110717601 cfsno long-term record
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-09-07 | 9 | 0 | 5/27 | p85 |
Top water assets
- 69Santa Ana Riverriver
- 69Santa Ana Riverriver
- 69Santa Ana Riverriver
- 69Cienaga Seca Creekriver
- 69Santa Ana Riverriver
- 69Bear Creekriver
- 69Santa Ana Riverriver
- 69Santa Ana Riverriver
- 69North Fork Lytle Creekriver
- 69South Fork Lytle Creekriver