USGS Streamgage 11135800
San Antonio C A Los Alamos, CA
San Antonio C A Los Alamos, CA is USGS streamgage 11135800 in California, monitoring river discharge in hydrologic subbasin 18060009. It drains a watershed of about 35 square miles. Discharge records at this site go back to 1970. Typical flow runs near 0 cfs in July and 0 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 35 sq mi
- Gauge elevation
- 579 ft
- Subbasin (HUC-8)
- 18060009
- Coordinates
- 34.74331, -120.27095
- USGS site number
- 11135800
- Records begin
- 1970-10-01 (56 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 56 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 | 0 | 0 | 0.4 | |
| February | 0 | 0 | 11 | |
| March | 0 | 0 | 11.4 | |
| April | 0 | 0 | 0.9 | |
| May | 0 | 0 | 0.1 | |
| June | 0 | 0 | 0 | |
| July | 0 | 0 | 0 | |
| August | 0 | 0 | 0 | |
| September | 0 | 0 | 0 | |
| October | 0 | 0 | 0 | |
| November | 0 | 0 | 0 | |
| December | 0 | 0 | 0.1 |
All values in cubic feet per second (cfs).
Common questions
- When does San Antonio C A Los Alamos, CA normally run highest?
- January, on the long-term record. The median daily flow that month is about 0 cfs, against 0 cfs in January, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for San Antonio C A Los Alamos, CA?
- It depends on the month. In January, half of days historically fall near 0 cfs, with the middle 80% of days between 0 and 0.4 cfs. The month-by-month table on this page gives the full range.
- How long has San Antonio C A Los Alamos, CA been measured?
- Discharge records at USGS site 11135800 begin in 1970, about 56 years, covering roughly 7,975 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is San Antonio C A Los Alamos, CA?
- The gauge sits at 34.74331, -120.27095, in California, in hydrologic subbasin 18060009, at an elevation of about 579 feet, draining roughly 35 square miles.
- Can I use San Antonio C A Los Alamos, 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.