USGS Streamgage 11214600
Helms C below Courtright Dam, CA
Helms C below Courtright Dam, CA is USGS streamgage 11214600 in California, monitoring river discharge in hydrologic subbasin 18030010. It drains a watershed of about 40 square miles. Discharge records at this site go back to 1958. Typical flow runs near 23.6 cfs in July and 10.6 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- California
- Drainage area
- 40 sq mi
- Subbasin (HUC-8)
- 18030010
- Coordinates
- 37.07633, -118.96872
- USGS site number
- 11214600
- Records begin
- 1958-10-01 (68 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 67 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 | 2.9 | 10.1 | 25.8 | |
| February | 3.2 | 9.8 | 24.6 | |
| March | 3.1 | 8.6 | 27.3 | |
| April | 3.1 | 10.6 | 40 | |
| May | 4.7 | 15.3 | 36.8 | |
| June | 6.8 | 23.2 | 66.3 | |
| July | 5.9 | 23.6 | 171.8 | |
| August | 4.2 | 23.2 | 435.4 | |
| September | 3.9 | 14.9 | 215.4 | |
| October | 3.4 | 10.5 | 30.5 | |
| November | 3.5 | 9.6 | 29.5 | |
| December | 2.8 | 9.8 | 27.4 |
All values in cubic feet per second (cfs).
Common questions
- When does Helms C below Courtright Dam, CA normally run highest?
- July, on the long-term record. The median daily flow that month is about 23.6 cfs, against 8.6 cfs in March, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Helms C below Courtright Dam, CA?
- It depends on the month. In January, half of days historically fall near 10.1 cfs, with the middle 80% of days between 2.9 and 25.8 cfs. The month-by-month table on this page gives the full range.
- How long has Helms C below Courtright Dam, CA been measured?
- Discharge records at USGS site 11214600 begin in 1958, about 68 years, covering roughly 8,821 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is Helms C below Courtright Dam, CA?
- The gauge sits at 37.07633, -118.96872, in California, in hydrologic subbasin 18030010, draining roughly 40 square miles.
- Can I use Helms C below Courtright Dam, 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.