USGS Streamgage 11516530
Klamath River below Iron Gate Dam, CA
Klamath River below Iron Gate Dam, CA is USGS streamgage 11516530 in California, monitoring river discharge in hydrologic subbasin 18010206. It drains a watershed of about 4,630 square miles. Discharge records at this site go back to 1960. Typical flow runs near 788 cfs in July and 2,053.7 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 4,630 sq mi
- Gauge elevation
- 2,166 ft
- Subbasin (HUC-8)
- 18010206
- Coordinates
- 41.92788, -122.44417
- USGS site number
- 11516530
- Records begin
- 1960-10-01 (66 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 66 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 | 953.4 | 1,740 | 4,398.7 | |
| February | 925.8 | 1,801 | 5,335.9 | |
| March | 975.1 | 2,260.6 | 6,984.8 | |
| April | 1,265.3 | 2,053.7 | 5,658.3 | |
| May | 1,019 | 1,603.5 | 4,005.8 | |
| June | 718.1 | 1,015 | 2,210.7 | |
| July | 694.9 | 788 | 1,080.3 | |
| August | 732.4 | 1,015.5 | 1,098.1 | |
| September | 888.1 | 1,199 | 1,576 | |
| October | 957.9 | 1,333.5 | 2,210.3 | |
| November | 972.5 | 1,343 | 3,116.7 | |
| December | 944.9 | 1,521.6 | 4,045.8 |
All values in cubic feet per second (cfs).
Common questions
- When does Klamath River below Iron Gate Dam, CA normally run highest?
- March, on the long-term record. The median daily flow that month is about 2,260.6 cfs, against 788 cfs in July, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Klamath River below Iron Gate Dam, CA?
- It depends on the month. In January, half of days historically fall near 1,740 cfs, with the middle 80% of days between 953.4 and 4,398.7 cfs. The month-by-month table on this page gives the full range.
- How long has Klamath River below Iron Gate Dam, CA been measured?
- Discharge records at USGS site 11516530 begin in 1960, about 66 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 Klamath River below Iron Gate Dam, CA?
- The gauge sits at 41.92788, -122.44417, in California, in hydrologic subbasin 18010206, at an elevation of about 2,166 feet, draining roughly 4,630 square miles.
- Can I use Klamath River below Iron Gate 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.