USGS Streamgage 11493500
Williamson River near Klamath Agency, OR
Williamson River near Klamath Agency, OR is USGS streamgage 11493500 in Oregon, monitoring river discharge in hydrologic subbasin 18010201. It drains a watershed of about 1,290 square miles. Discharge records at this site go back to 1910. Typical flow runs near 1.9 cfs in July and 280.9 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- Oregon
- Drainage area
- 1,290 sq mi
- Gauge elevation
- 4,487 ft
- Subbasin (HUC-8)
- 18010201
- Coordinates
- 42.73992, -121.83452
- USGS site number
- 11493500
- Records begin
- 1910-03-13 (116 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 72 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 | 0 | 102.2 | 381.6 | |
| February | 0 | 148.6 | 497.7 | |
| March | 0 | 280.6 | 684.6 | |
| April | 0 | 280.9 | 720.3 | |
| May | 0.2 | 157.5 | 490.6 | |
| June | 0 | 46 | 276.1 | |
| July | 0 | 1.9 | 112.4 | |
| August | 0 | 0 | 28.8 | |
| September | 0 | 0 | 37.7 | |
| October | 0 | 0 | 110.4 | |
| November | 0 | 2.4 | 270.4 | |
| December | 0 | 100.6 | 371.7 |
All values in cubic feet per second (cfs).
Common questions
- When does Williamson River near Klamath Agency, OR normally run highest?
- April, on the long-term record. The median daily flow that month is about 280.9 cfs, against 0 cfs in August, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Williamson River near Klamath Agency, OR?
- It depends on the month. In January, half of days historically fall near 102.2 cfs, with the middle 80% of days between 0 and 381.6 cfs. The month-by-month table on this page gives the full range.
- How long has Williamson River near Klamath Agency, OR been measured?
- Discharge records at USGS site 11493500 begin in 1910, about 116 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 Williamson River near Klamath Agency, OR?
- The gauge sits at 42.73992, -121.83452, in Oregon, in hydrologic subbasin 18010201, at an elevation of about 4,487 feet, draining roughly 1,290 square miles.
- Can I use Williamson River near Klamath Agency, OR 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.