USGS Streamgage 111626182
Pilarcitos C below Spillway near Hillsborough, CA
Pilarcitos C below Spillway near Hillsborough, CA is USGS streamgage 111626182 in California, monitoring river discharge in hydrologic subbasin 18050006. It drains a watershed of about 4 square miles. Discharge records at this site go back to 2022. Typical flow runs near 2 cfs in July and 1.2 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- California
- Drainage area
- 4 sq mi
- Gauge elevation
- 614 ft
- Subbasin (HUC-8)
- 18050006
- Coordinates
- 37.54769, -122.42089
- USGS site number
- 111626182
- Records begin
- 2022-03-01 (4 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 5 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.
| Month | Low p10 | Typical p50 | High p90 | Range |
|---|---|---|---|---|
| January | — | 3.9 | — | |
| February | — | 4.4 | — | |
| March | — | 1 | — | |
| April | — | 1.2 | — | |
| May | — | 2.1 | — | |
| June | — | 2.3 | — | |
| July | — | 2 | — | |
| August | — | 1.9 | — | |
| September | — | 2 | — | |
| October | — | 2.5 | — | |
| November | — | 1.8 | — | |
| December | — | 1.9 | — |
All values in cubic feet per second (cfs).
Common questions
- When does Pilarcitos C below Spillway near Hillsborough, CA normally run highest?
- February, on the long-term record. The median daily flow that month is about 4.4 cfs, against 1 cfs in March, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- How long has Pilarcitos C below Spillway near Hillsborough, CA been measured?
- Discharge records at USGS site 111626182 begin in 2022, about 4 years, covering roughly 1,614 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is Pilarcitos C below Spillway near Hillsborough, CA?
- The gauge sits at 37.54769, -122.42089, in California, in hydrologic subbasin 18050006, at an elevation of about 614 feet, draining roughly 4 square miles.
- Can I use Pilarcitos C below Spillway near Hillsborough, CA data for flood or safety decisions?
- No. Rivermatics provides estimates, not guarantees, and the readings and forecasts here may be delayed, inaccurate, or wrong. Do not use them for navigation or for any safety, rescue, or emergency decision. Check the National Weather Service and USGS directly, and use your own judgment.