Upper Poso HUC8 18030004
A 1,490 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
68
Moderate
Drought index
55
Abnormally dry
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
—
no gauges reporting
Median flow
—
of normal for the date
Water assets
920
0 springs · 706 wells
USGS gauges (0)
No active discharge gauges in this sub-basin.
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-09-07 | 55 | 0 | — | — |
Top water assets
- 67Poso Creekriver
- 67Poso Creekriver
- 67Sandy Creekriver
- 67Poso Creekriver
- 67Poso Creekriver
- 67Poso Creekriver
- 67Poso Creekriver
- 67Alder Creekriver
- 67Poso Creekriver
- 67Little Poso Creekriver