USGS Streamgage 14378200
Illinois River near Agness, OR
Illinois River near Agness, OR is USGS streamgage 14378200 in Oregon, monitoring river discharge in hydrologic subbasin 17100311. It drains a watershed of about 988 square miles. Discharge records at this site go back to 1960. Typical flow runs near 365.3 cfs in July and 3,835.7 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- Oregon
- Drainage area
- 988 sq mi
- Subbasin (HUC-8)
- 17100311
- Coordinates
- 42.54488, -124.05191
- USGS site number
- 14378200
- Records begin
- 1960-10-01 (66 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 | 1,281.1 | 5,303.2 | 30,893.5 | |
| February | 2,083.6 | 5,763.8 | 19,898.9 | |
| March | 2,246.8 | 5,181.6 | 17,416.1 | |
| April | 1,474.3 | 3,835.7 | 9,029.7 | |
| May | 1,093.1 | 1,788.7 | 5,642.3 | |
| June | 576.4 | 797.9 | 1,407.1 | |
| July | 262.6 | 365.3 | 506.6 | |
| August | 160.4 | 221.1 | 318.5 | |
| September | 149.1 | 186 | 466.3 | |
| October | 172.9 | 353.1 | 2,160.7 | |
| November | 419.8 | 2,348 | 14,982 | |
| December | 992.3 | 4,726.5 | 24,925.8 |
All values in cubic feet per second (cfs).