San Gregorio C at San Gregorio CA
USGS Site No: 11162570 • San Mateo County, CA
San Gregorio C at San Gregorio CA is currently at 11 cfs (High — 94th percentile for this date) . Gage height: 3.88 ft.
Reading from
Historical Percentile Comparison
Today's discharge compared to the long-term record for October 28 at this station. Percentile rank shows what fraction of historical years had lower flow on this date.
| Percentile | Label | CFS Threshold | Today's Flow |
|---|---|---|---|
| 10th | Very Low threshold | 0 | |
| 25th | Low threshold | 1 | |
| 50th (Median) | Normal (median) | 2 | |
| 75th | High threshold | 4 | |
| 95th | Very High threshold | 11 | Today: 11 cfs |
30-Day Hydrograph
Recent discharge plotted against the historical 10th–95th percentile envelope for the same calendar days. Source: USGS daily values + long-term statistics.
30-Day Flow History
| Date | Discharge (CFS) | Gage Ht (ft) |
|---|---|---|
| May 28, 2026 | 12 | — |
| May 27, 2026 | 10 | — |
| May 26, 2026 | 10 | — |
| May 25, 2026 | 10 | — |
| May 24, 2026 | 10 | — |
| May 23, 2026 | 11 | — |
| May 22, 2026 | 10 | — |
| May 21, 2026 | 11 | — |
| May 20, 2026 | 11 | — |
| May 19, 2026 | 11 | — |
| May 18, 2026 | 12 | — |
| May 17, 2026 | 13 | — |
| May 16, 2026 | 13 | — |
| May 15, 2026 | 13 | — |
| Apr 20, 2026 | 24 | — |
| Apr 19, 2026 | 17 | — |
| Apr 18, 2026 | 18 | — |
| Apr 17, 2026 | 20 | — |
| Apr 16, 2026 | 24 | — |
| Apr 15, 2026 | 27 | — |
| Apr 14, 2026 | 36 | — |
| Apr 13, 2026 | 60 | — |
| Apr 12, 2026 | 73 | — |
| Apr 11, 2026 | 43 | — |
| Apr 10, 2026 | 15 | — |
| Apr 9, 2026 | 10 | — |
| Apr 8, 2026 | 10 | — |
| Apr 7, 2026 | 10 | — |
| Apr 6, 2026 | 10 | — |
| Apr 5, 2026 | 10 | — |
Station Information
- USGS Site No
- 11162570
- State
- CA
- County
- San Mateo County
- Coordinates
- 37.3257, -122.3866
- Drainage Area
- 51 mi²
- Datum (ft)
- 13.5
- HUC Code
- 18050006
Flood Stage Thresholds
- Action Stage
- 15.0 ft
- Flood Stage
- 17.7 ft
- Moderate Flood
- 21.0 ft
- Major Flood
- 25.0 ft
Currently 13.82 ft below flood stage.
Recent Extremes
- Max discharge
-
872 cfsJan 4, 2026
- Min discharge
-
2 cfsOct 10, 2025
- Days at flood stage
- 0
Computed from the local daily-values archive.
Nearby Gauges
-
Pescadero C near Pescadero CAHigh5.5 mi · 15 cfs
-
Butano C near Pescadero CAVery High6.4 mi · 8 cfs
-
Pilarcitos C at Half Moon Bay CAHigh10.1 mi · 6 cfs
-
San Francisquito C at Stanford University CAVery High12.8 mi · 5 cfs
-
Pilarcitos C below Stone Dam near Hillsborough CAHigh13.8 mi · 2 cfs