USGS Streamgage 14243000
Cowlitz River at Castle Rock, WA
Cowlitz River at Castle Rock, WA is USGS streamgage 14243000 in Washington, monitoring river discharge in hydrologic subbasin 17080005. It drains a watershed of about 2,238 square miles. Discharge records at this site go back to 1926. Typical flow runs near 4,527.7 cfs in July and 9,161.7 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- Washington
- Drainage area
- 2,238 sq mi
- Subbasin (HUC-8)
- 17080005
- Coordinates
- 46.27483, -122.91456
- USGS site number
- 14243000
- Records begin
- 1926-12-10 (100 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 99 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 | 5,960 | 12,451.6 | 25,461.3 | |
| February | 5,781.4 | 11,027.6 | 22,631 | |
| March | 5,784.8 | 9,609.4 | 17,800 | |
| April | 5,990 | 9,161.7 | 15,996.7 | |
| May | 5,111.6 | 9,642.6 | 16,032.3 | |
| June | 4,218.3 | 8,376.3 | 15,233.3 | |
| July | 2,778.7 | 4,527.7 | 9,069.7 | |
| August | 2,098.7 | 2,999.4 | 4,651.6 | |
| September | 1,692.3 | 2,877 | 4,809 | |
| October | 1,776.1 | 4,304.2 | 8,113.5 | |
| November | 3,400.3 | 8,998.7 | 20,400 | |
| December | 5,619.7 | 12,561.3 | 26,174.2 |
All values in cubic feet per second (cfs).