USGS Streamgage 14203500
Tualatin River near Dilley, OR
Tualatin River near Dilley, OR is USGS streamgage 14203500 in Oregon, monitoring river discharge in hydrologic subbasin 17090010. It drains a watershed of about 125 square miles. Discharge records at this site go back to 1939. Typical flow runs near 117.4 cfs in July and 305.1 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- Oregon
- Drainage area
- 125 sq mi
- Subbasin (HUC-8)
- 17090010
- Coordinates
- 45.47484, -123.12427
- USGS site number
- 14203500
- Records begin
- 1939-10-01 (87 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 87 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 | 207.7 | 737 | 1,955.2 | |
| February | 189.4 | 575.3 | 1,679.3 | |
| March | 199.3 | 505.4 | 1,207.6 | |
| April | 130.5 | 305.1 | 717.5 | |
| May | 90.4 | 149.9 | 332.9 | |
| June | 53 | 98.6 | 195.7 | |
| July | 16.7 | 117.4 | 225.7 | |
| August | 5.9 | 140.6 | 244.1 | |
| September | 9.2 | 117.4 | 225.9 | |
| October | 20.1 | 108.8 | 226.5 | |
| November | 57.8 | 214.3 | 859.4 | |
| December | 126.4 | 569.5 | 1,764.2 |
All values in cubic feet per second (cfs).
Other gauges in this subbasin
- EF Dairy Creek above Murtaugh Creek near Meacham Corner, OR
- Tualatin River at Hwy 219 near Hillsboro, OR
- Rock Creek above Bethany Lake, near Bethany, OR
- Rock Creek near Bethany Lake, near Bethany, OR
- Rock Creek below Bethany Lake, near Bethany, OR
- Tualatin River at River Mile 24.5, near Scholls, OR
- Chicken Creek above Seasonal Trail, near Sherwood, OR
- Fanno Creek at 56Th Ave, at Portland, OR