USGS Streamgage 11522500
Salmon River A Somes Bar, CA
Salmon River A Somes Bar, CA is USGS streamgage 11522500 in California, monitoring river discharge in hydrologic subbasin 18010210. It drains a watershed of about 751 square miles. Discharge records at this site go back to 1911. Typical flow runs near 480.1 cfs in July and 2,832.7 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 751 sq mi
- Gauge elevation
- 486 ft
- Subbasin (HUC-8)
- 18010210
- Coordinates
- 41.37649, -123.47696
- USGS site number
- 11522500
- Records begin
- 1911-10-01 (115 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 115 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 | 519.1 | 1,774.8 | 6,452.3 | |
| February | 830.8 | 2,139 | 5,918.6 | |
| March | 1,161.3 | 2,355.8 | 5,277.1 | |
| April | 1,350 | 2,832.7 | 5,029.3 | |
| May | 1,191.3 | 2,844.2 | 5,216.8 | |
| June | 581.6 | 1,537 | 3,602.3 | |
| July | 240.1 | 480.1 | 1,131.5 | |
| August | 135.6 | 234.7 | 380.5 | |
| September | 114.8 | 185.3 | 270.7 | |
| October | 128.8 | 209 | 570.8 | |
| November | 195.7 | 478.6 | 2,299 | |
| December | 317.4 | 1,103.9 | 5,290 |
All values in cubic feet per second (cfs).
Common questions
- When does Salmon River A Somes Bar, CA normally run highest?
- May, on the long-term record. The median daily flow that month is about 2,844.2 cfs, against 185.3 cfs in September, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Salmon River A Somes Bar, CA?
- It depends on the month. In January, half of days historically fall near 1,774.8 cfs, with the middle 80% of days between 519.1 and 6,452.3 cfs. The month-by-month table on this page gives the full range.
- How long has Salmon River A Somes Bar, CA been measured?
- Discharge records at USGS site 11522500 begin in 1911, about 115 years, covering roughly 9,126 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is Salmon River A Somes Bar, CA?
- The gauge sits at 41.37649, -123.47696, in California, in hydrologic subbasin 18010210, at an elevation of about 486 feet, draining roughly 751 square miles.
- Can I use Salmon River A Somes Bar, 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.