USGS Streamgage 12031000
Chehalis River at Porter, WA
Chehalis River at Porter, WA is USGS streamgage 12031000 in Washington, monitoring river discharge in hydrologic subbasin 17100103. It drains a watershed of about 1,294 square miles. Discharge records at this site go back to 1947. Typical flow runs near 566.6 cfs in July and 3,683.7 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- Washington
- Drainage area
- 1,294 sq mi
- Gauge elevation
- 38 ft
- Subbasin (HUC-8)
- 17100103
- Coordinates
- 46.93926, -123.31432
- USGS site number
- 12031000
- Records begin
- 1947-01-26 (79 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 74 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 | 2,668.1 | 7,216.1 | 19,922.6 | |
| February | 2,779.3 | 5,969.3 | 16,500 | |
| March | 2,560.6 | 5,239.7 | 12,905.8 | |
| April | 2,014 | 3,683.7 | 8,255.7 | |
| May | 1,106.5 | 1,849 | 3,890.6 | |
| June | 671.3 | 1,036.6 | 2,151.3 | |
| July | 393.7 | 566.6 | 885.6 | |
| August | 264.4 | 376.9 | 568 | |
| September | 272.1 | 407.6 | 897.1 | |
| October | 347.6 | 737.4 | 2,862.2 | |
| November | 904.3 | 3,779 | 12,941.3 | |
| December | 2,323.5 | 6,364.2 | 19,561.3 |
All values in cubic feet per second (cfs).
Other gauges in this subbasin
- Chehalis River near Doty, WA
- Elk Creek below Deer Creek near Doty, WA
- South Fork Chehalis River near Wildwood, WA
- Chehalis River near Adna, WA
- South Fork Newaukum River near Onalaska, WA
- NF Newaukum River above Bear Creek near Forest, WA
- Newaukum River near Chehalis, WA
- Chehalis River at Wwtp at Chehalis, WA