USGS Streamgage 12436500
Columbia River at Grand Coulee, WA
Columbia River at Grand Coulee, WA is USGS streamgage 12436500 in Washington, monitoring river discharge in hydrologic subbasin 17020005. It sits on the Columbia River, alongside 12 other gauges Rivermatics tracks on the same river. It drains a watershed of about 74,700 square miles. Discharge records at this site go back to 1894. Typical flow runs near 154,290.3 cfs in July and 93,843.3 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Washington
- Drainage area
- 74,700 sq mi
- Gauge elevation
- 961 ft
- Subbasin (HUC-8)
- 17020005
- Coordinates
- 47.96543, -118.9828
- USGS site number
- 12436500
- Records begin
- 1894-06-01 (132 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 103 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 | 36,903.2 | 82,635.5 | 135,838.7 | |
| February | 35,920.7 | 80,055.2 | 137,413.8 | |
| March | 39,593.5 | 77,758.1 | 134,645.2 | |
| April | 52,160 | 93,843.3 | 155,400 | |
| May | 82,751.6 | 147,193.5 | 258,096.8 | |
| June | 90,036.7 | 194,333.3 | 348,866.7 | |
| July | 83,193.5 | 154,290.3 | 259,709.7 | |
| August | 76,829 | 105,932.3 | 145,419.4 | |
| September | 52,326.7 | 71,083.3 | 95,236.7 | |
| October | 44,864.5 | 64,093.5 | 90,145.2 | |
| November | 40,063.3 | 72,843.3 | 103,133.3 | |
| December | 36,874.2 | 79,125.8 | 121,893.5 |
All values in cubic feet per second (cfs).
Common questions
- When does Columbia River at Grand Coulee, WA normally run highest?
- June, on the long-term record. The median daily flow that month is about 194,333.3 cfs, against 64,093.5 cfs in October, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Columbia River at Grand Coulee, WA?
- It depends on the month. In January, half of days historically fall near 82,635.5 cfs, with the middle 80% of days between 36,903.2 and 135,838.7 cfs. The month-by-month table on this page gives the full range.
- How long has Columbia River at Grand Coulee, WA been measured?
- Discharge records at USGS site 12436500 begin in 1894, about 132 years, covering roughly 9,123 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is Columbia River at Grand Coulee, WA?
- The gauge sits at 47.96543, -118.9828, in Washington, in hydrologic subbasin 17020005, at an elevation of about 961 feet, draining roughly 74,700 square miles.
- Can I use Columbia River at Grand Coulee, WA 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.
Upstream and downstream on the Columbia River
Every gauge Rivermatics tracks on this river, ordered by drainage area — upstream first. See the Columbia River in full.
- Columbia River at International Boundary 59,700 sq mi
- Columbia River at Grand Coulee, WA this page
- Columbia River at Bridgeport, WA 75,700 sq mi
- Columbia River below Wells Dam, WA 86,100 sq mi
- Columbia River at Rocky Reach Dam, WA 87,800 sq mi
- Columbia River below Rock Island Dam, WA 89,400 sq mi
- Columbia River below Priest Rapids Dam, WA 96,000 sq mi
- Columbia River at McNary Dam,Near Umatilla, OR 214,000 sq mi
- Columbia River at the Dalles, OR 237,000 sq mi
- Columbia River below Bonneville Dam, OR 239,900 sq mi
- Columbia River at Bonneville Dam Forebay, WA
- Columbia River at Cascade Island, WA
- Columbia River at the Dalles Dam Forebay, WA