USGS Streamgage 12321500
Boundary Creek near Porthill, ID
Boundary Creek near Porthill, ID is USGS streamgage 12321500 in Idaho, monitoring river discharge in hydrologic subbasin 17010104. It drains a watershed of about 97 square miles. Discharge records at this site go back to 1928. Typical flow runs near 107.5 cfs in July and 243.7 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- Idaho
- Drainage area
- 97 sq mi
- Gauge elevation
- 1,778 ft
- Subbasin (HUC-8)
- 17010104
- Coordinates
- 48.99722, -116.56917
- USGS site number
- 12321500
- Records begin
- 1928-05-17 (98 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 98 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 | 22.7 | 41.9 | 89.4 | |
| February | 22 | 40 | 106.1 | |
| March | 27.1 | 58.2 | 161.2 | |
| April | 89.2 | 243.7 | 541.2 | |
| May | 420 | 784.6 | 1,407.1 | |
| June | 197.8 | 553.1 | 1,090.2 | |
| July | 46.7 | 107.5 | 268.7 | |
| August | 20.2 | 33.7 | 71.1 | |
| September | 16.6 | 27.1 | 60.8 | |
| October | 19.2 | 34.5 | 119.2 | |
| November | 23.2 | 51.4 | 185.6 | |
| December | 24.4 | 48.2 | 144 |
All values in cubic feet per second (cfs).