San Francisco Coastal South HUC8 18050006
A 1,746 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
76
Healthy
Drought index
0
None
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
20%
of 5 reporting
Median flow
86%
p46 of record
Water assets
190
10 springs · 132 wells
USGS gauges (7)
- BUTANO C NR PESCADERO CA111625401 cfsp19 · below normal
- PESCADERO C NR PESCADERO CA111625002 cfsp40 · normal
- SAN GREGORIO C A SAN GREGORIO CA111625701 cfsp46 · normal
- PILARCITOS C BL STONE DAM NR HILLSBOROUGH CA111626202 cfsp48 · normal
- PILARCITOS C A HALF MOON BAY CA111626302 cfsp69 · normal
- PILARCITOS C BL SPILLWAY NR HILLSBOROUGH CA1116261823 cfsno long-term record
- PILARCITOS C AB STONE DAM NR HILLSBOROUGH CA111626193 cfsno long-term record
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-10-20 | 0 | 0 | 1/5 | p46 |
| 2026-10-19 | 0 | 0 | 1/5 | p47 |
| 2026-10-18 | 0 | 0 | 0/5 | p48 |
| 2026-10-17 | 0 | 0 | 0/5 | p46 |
| 2026-10-16 | 0 | 0 | 0/5 | p38 |
| 2026-10-15 | 0 | 0 | 0/5 | p50 |
| 2026-10-14 | 0 | 0 | 1/5 | p57 |
| 2026-10-13 | 0 | 0 | 0/5 | p60 |
| 2026-10-12 | 0 | 0 | 0/5 | p60 |
| 2026-10-11 | 0 | 0 | 0/5 | p60 |
| 2026-10-10 | 0 | 0 | 0/5 | p67 |
| 2026-10-09 | 0 | 0 | 0/5 | p61 |
| 2026-10-08 | 0 | 0 | 0/5 | p61 |
| 2026-10-07 | 0 | 0 | 0/5 | p67 |
Top water assets
- 67Pilarcitosreservoir
- 65San Gregorio C A San Gregorio Cariver
- 65Pilarcitos C Ab Stone Dam Nr Hillsborough Cariver
- 65Pilarcitos C A Half Moon Bay Cariver
- 65Pescadero C Nr Pescadero Cariver
- 65Butano C Nr Pescadero Cariver
- 65Pilarcitos C Bl Stone Dam Nr Hillsborough Cariver
- 62Pilarcitos C Bl Spillway Nr Hillsborough Cariver
- 61Landino Construction And Well Drilling Well — Wcr0002458well
- 52Digges & Son Well — Wcr0003222well