USGS Streamgage 11475000
Eel River A Fort Seward, CA
Eel River A Fort Seward, CA is USGS streamgage 11475000 in California, monitoring river discharge in hydrologic subbasin 18010105. It drains a watershed of about 2,107 square miles. Discharge records at this site go back to 1955. Typical flow runs near 107.9 cfs in July and 3,563 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 2,107 sq mi
- Gauge elevation
- 220 ft
- Subbasin (HUC-8)
- 18010105
- Coordinates
- 40.21817, -123.6325
- USGS site number
- 11475000
- Records begin
- 1955-09-01 (71 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 71 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 | 600.7 | 4,994.8 | 33,532.3 | |
| February | 1,233.3 | 5,629.7 | 31,117.2 | |
| March | 1,571.3 | 6,080 | 22,374.2 | |
| April | 1,162.3 | 3,563 | 12,018 | |
| May | 515.7 | 1,461 | 4,925.5 | |
| June | 158.8 | 431 | 1,570.9 | |
| July | 50 | 107.9 | 293.7 | |
| August | 14.2 | 40.9 | 99.8 | |
| September | 12.8 | 34.3 | 73.3 | |
| October | 26.2 | 66.7 | 570.9 | |
| November | 81.3 | 421.1 | 6,677 | |
| December | 219.3 | 2,391.6 | 23,387.1 |
All values in cubic feet per second (cfs).
Common questions
- When does Eel River A Fort Seward, CA normally run highest?
- March, on the long-term record. The median daily flow that month is about 6,080 cfs, against 34.3 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 Eel River A Fort Seward, CA?
- It depends on the month. In January, half of days historically fall near 4,994.8 cfs, with the middle 80% of days between 600.7 and 33,532.3 cfs. The month-by-month table on this page gives the full range.
- How long has Eel River A Fort Seward, CA been measured?
- Discharge records at USGS site 11475000 begin in 1955, about 71 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 Eel River A Fort Seward, CA?
- The gauge sits at 40.21817, -123.6325, in California, in hydrologic subbasin 18010105, at an elevation of about 220 feet, draining roughly 2,107 square miles.
- Can I use Eel River A Fort Seward, 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.