USGS Streamgage 11468900
Mattole River near Ettersburg, CA
Mattole River near Ettersburg, CA is USGS streamgage 11468900 in California, monitoring river discharge in hydrologic subbasin 18010107. It drains a watershed of about 71 square miles. Discharge records at this site go back to 2001. Typical flow runs near 18.3 cfs in July and 257.9 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 71 sq mi
- Gauge elevation
- 582 ft
- Subbasin (HUC-8)
- 18010107
- Coordinates
- 40.13928, -123.9914
- USGS site number
- 11468900
- Records begin
- 2001-06-21 (25 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 25 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 | 100.5 | 525.7 | 2,301.6 | |
| February | 101.1 | 402.9 | 2,063.2 | |
| March | 80.5 | 452.4 | 1,977.4 | |
| April | 76.2 | 257.9 | 1,065.1 | |
| May | 42.8 | 93.9 | 408.4 | |
| June | 21.9 | 40.3 | 137.3 | |
| July | 10 | 18.3 | 42.8 | |
| August | 4.6 | 9.1 | 18.9 | |
| September | 3.8 | 6.4 | 15.9 | |
| October | 4.7 | 9.5 | 136.5 | |
| November | 10.8 | 55.9 | 656.9 | |
| December | 36.3 | 423.8 | 2,601.5 |
All values in cubic feet per second (cfs).
Common questions
- When does Mattole River near Ettersburg, CA normally run highest?
- January, on the long-term record. The median daily flow that month is about 525.7 cfs, against 6.4 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 Mattole River near Ettersburg, CA?
- It depends on the month. In January, half of days historically fall near 525.7 cfs, with the middle 80% of days between 100.5 and 2,301.6 cfs. The month-by-month table on this page gives the full range.
- How long has Mattole River near Ettersburg, CA been measured?
- Discharge records at USGS site 11468900 begin in 2001, about 25 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 Mattole River near Ettersburg, CA?
- The gauge sits at 40.13928, -123.9914, in California, in hydrologic subbasin 18010107, at an elevation of about 582 feet, draining roughly 71 square miles.
- Can I use Mattole River near Ettersburg, 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.