USGS Streamgage 12502500
Ahtanum Creek at Union Gap, WA
Ahtanum Creek at Union Gap, WA is USGS streamgage 12502500 in Washington, monitoring river discharge in hydrologic subbasin 17030003. It drains a watershed of about 173 square miles. Discharge records at this site go back to 1904. Typical flow runs near 21.1 cfs in July and 117 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- Washington
- Drainage area
- 173 sq mi
- Gauge elevation
- 959 ft
- Subbasin (HUC-8)
- 17030003
- Coordinates
- 46.53596, -120.4734
- USGS site number
- 12502500
- Records begin
- 1904-05-01 (122 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 | 17.1 | 47.6 | 129.4 | |
| February | 28.7 | 69.8 | 252.8 | |
| March | 43.2 | 94.9 | 273.4 | |
| April | 43.3 | 117 | 252 | |
| May | 43.1 | 139.7 | 353.9 | |
| June | 23.1 | 89 | 290.5 | |
| July | 10.1 | 21.1 | 71.1 | |
| August | 9 | 15.8 | 25.5 | |
| September | 11.7 | 20.1 | 29.6 | |
| October | 12.4 | 22 | 34.9 | |
| November | 11.6 | 27.8 | 54.7 | |
| December | 14.6 | 35.1 | 94.8 |
All values in cubic feet per second (cfs).