San Joaquin Delta HUC8 18040003
A 3,192 km² sub-basin of the California region in CA. Drought coverage is from the US Drought Monitor (map of 2026-10-13); streamflow classes place each USGS gauge's latest reading against its own day-of-year record.
Health score
79
Healthy
Drought index
8
Abnormally dry
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
0%
of 1 reporting
Median flow
125%
p65 of record
Water assets
1,872
0 springs · 1,812 wells
USGS gauges (16)
- SAN JOAQUIN R NR VERNALIS CA113035002,430 cfsp65 · normal
- SAN JOAQUIN R BL GARWOOD BRIDGE A STOCKTON CA11304810-980 cfsno long-term record
- TURNER CUT NR HOLT CA11311300no readingno long-term record
- MIDDLE R AT MIDDLE RIVER CA11312676no readingno long-term record
- MIDDLE R NR HOLT CA11312685no readingno long-term record
- OLD R NR DELTA MENDOTA CANAL CA11312968-848 cfsno long-term record
- GRANT LINE CN NR TRACY CA11313240no readingno long-term record
- OLD RIVER NEAR BYRON CA11313315no readingno long-term record
- OLD R A BACON ISLAND CA11313405no readingno long-term record
- HOLLAND CUT NR BETHEL ISLAND CA113134317,790 cfsno long-term record
- DUTCH SLOUGH BL JERSEY ISLAND RD A JERSEY ISLAND113134331,290 cfsno long-term record
- OLD R A QUIMBY ISLAND NR BETHEL ISLAND CA113134342,760 cfsno long-term record
- FALSE R NR OAKLEY CA1131344013,000 cfsno long-term record
- OLD R A FRANKS TRACT NR TERMINOUS CA11313452no readingno long-term record
- SAN JOAQUIN R A PRISONERS PT NR TERMINOUS CA11313460no readingno long-term record
- SAN JOAQUIN R A JERSEY POINT CA113371909,600 cfsno long-term record
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-10-19 | 8 | 0 | 0/1 | p65 |
| 2026-10-18 | 8 | 0 | 0/1 | p47 |
| 2026-10-17 | 8 | 0 | 1/1 | p25 |
| 2026-10-16 | 8 | 0 | 1/1 | p14 |
| 2026-10-15 | 8 | 0 | 1/1 | p17 |
| 2026-10-14 | 8 | 0 | 0/1 | p25 |
| 2026-10-13 | 8 | 0 | 0/1 | p30 |
| 2026-10-12 | 8 | 0 | 0/1 | p28 |
| 2026-10-11 | 8 | 0 | 0/1 | p26 |
| 2026-10-10 | 8 | 0 | 1/1 | p23 |
| 2026-10-09 | 8 | 0 | 1/1 | p22 |
| 2026-10-08 | 8 | 0 | 1/1 | p22 |
| 2026-10-07 | 8 | 0 | 0/1 | p28 |
| 2026-10-06 | 8 | 0 | 0/1 | p28 |
Top water assets
- 65False R Nr Oakley Cariver
- 65Bear Creekriver
- 65San Joaquin R Nr Vernalis Cariver
- 65San Joaquin Riverriver
- 65Holland Cut Nr Bethel Island Cariver
- 65Dutch Slough Bl Jersey Island Rd A Jersey Islandriver
- 65Old R A Quimby Island Nr Bethel Island Cariver
- 64Antioch Brackish Water Desalreservoir
- 54002N006E08N001Mwell
- 54002N006E29H001Mwell