USGS Streamgage 11528100
SF Trinity River A Forest Glen, CA
SF Trinity River A Forest Glen, CA is USGS streamgage 11528100 in California, monitoring river discharge in hydrologic subbasin 18010212. It drains a watershed of about 208 square miles. Discharge records at this site go back to 1954. Typical flow runs near 50.8 cfs in July and 443.2 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 208 sq mi
- Gauge elevation
- 2,261 ft
- Subbasin (HUC-8)
- 18010212
- Coordinates
- 40.37549, -123.32855
- USGS site number
- 11528100
- Records begin
- 1954-11-23 (72 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 6 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 | — | 284.2 | — | |
| February | — | 867.2 | — | |
| March | — | 458.8 | — | |
| April | — | 443.2 | — | |
| May | — | 265.5 | — | |
| June | — | 136.6 | — | |
| July | — | 50.8 | — | |
| August | — | 29.1 | — | |
| September | — | 20.4 | — | |
| October | — | 24.1 | — | |
| November | — | 107.5 | — | |
| December | — | 270.5 | — |
All values in cubic feet per second (cfs).
Common questions
- When does SF Trinity River A Forest Glen, CA normally run highest?
- February, on the long-term record. The median daily flow that month is about 867.2 cfs, against 20.4 cfs in September, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- How long has SF Trinity River A Forest Glen, CA been measured?
- Discharge records at USGS site 11528100 begin in 1954, about 72 years, covering roughly 7 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is SF Trinity River A Forest Glen, CA?
- The gauge sits at 40.37549, -123.32855, in California, in hydrologic subbasin 18010212, at an elevation of about 2,261 feet, draining roughly 208 square miles.
- Can I use SF Trinity River A Forest Glen, 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.