USGS Streamgage 12456500
Chiwawa River near Plain, WA
Chiwawa River near Plain, WA is USGS streamgage 12456500 in Washington, monitoring river discharge in hydrologic subbasin 17020011. It drains a watershed of about 170 square miles. Discharge records at this site go back to 1911. Typical flow runs near 657.5 cfs in July and 570 cfs in April, with the higher of the two arriving in July. Rivermatics issues a daily machine-learned flow outlook for this gauge, reaching 14 days ahead.
View live conditions & forecast →
Gauge details
- State
- Washington
- Drainage area
- 170 sq mi
- Gauge elevation
- 2,120 ft
- Subbasin (HUC-8)
- 17020011
- Coordinates
- 47.83731, -120.66229
- USGS site number
- 12456500
- Records begin
- 1911-05-29 (115 years)
- Rivermatics forecast
- 14-day flow outlook
14-day flow forecast
Based on observations through for Chiwawa River near Plain, WA. Each day carries a median estimate and the band the model expects the flow to fall within — not a single number to plan against. Forecasts are re-issued daily; see the live screen for the current outlook.
| Date | Low p10 | Expected p50 | High p90 | Range |
|---|---|---|---|---|
| 84.7 | 89.3 | 93 | ||
| 83.2 | 88.8 | 94.3 | ||
| 88 | 98 | 118 | ||
| 89.5 | 101 | 129 | ||
| 87.9 | 98.2 | 120 | ||
| 85.3 | 94.9 | 112 | ||
| 83 | 92.2 | 106 | ||
| 81.5 | 90.7 | 103 | ||
| 79.2 | 88.4 | 100 | ||
| 77.7 | 86.9 | 98.1 | ||
| 76.3 | 85.5 | 96.3 | ||
| 74.9 | 84.2 | 94.7 | ||
| 73.8 | 83.1 | 93.6 | ||
| 72.6 | 82.3 | 92.8 |
All values in cubic feet per second (cfs). Estimates only — do not use them for navigation or for any safety, rescue, or emergency decision.
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 115 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 | 81.4 | 137.4 | 300.9 | |
| February | 75.6 | 134.2 | 331.9 | |
| March | 95.8 | 170.4 | 434.7 | |
| April | 251.3 | 570 | 1,112 | |
| May | 810.3 | 1,423.5 | 2,683.9 | |
| June | 707.6 | 1,426.3 | 2,452.3 | |
| July | 282.5 | 657.5 | 1,434.6 | |
| August | 119.9 | 208.2 | 466.6 | |
| September | 83.5 | 126.7 | 241.6 | |
| October | 80.2 | 131.7 | 312.1 | |
| November | 92.8 | 180.1 | 522.3 | |
| December | 88.5 | 153.5 | 367.8 |
All values in cubic feet per second (cfs).
Common questions
- When does Chiwawa River near Plain, WA normally run highest?
- June, on the long-term record. The median daily flow that month is about 1,426.3 cfs, against 126.7 cfs in September, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Chiwawa River near Plain, WA?
- It depends on the month. In January, half of days historically fall near 137.4 cfs, with the middle 80% of days between 81.4 and 300.9 cfs. The month-by-month table on this page gives the full range.
- How long has Chiwawa River near Plain, WA been measured?
- Discharge records at USGS site 12456500 begin in 1911, about 115 years, covering roughly 9,200 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Is there a flow forecast for Chiwawa River near Plain, WA?
- Yes. Rivermatics trains a machine-learned model — a temporal-fusion transformer — on this basin's observed flows, weather, and snowpack, and issues a daily flow outlook reaching 14 days ahead: a median estimate inside a confidence band, not a single number to bet on. Every forecast is scored against days the model never trained on, and that track record is published on the live gauge screen. Open live conditions to see the current outlook.
- Where is Chiwawa River near Plain, WA?
- The gauge sits at 47.83731, -120.66229, in Washington, in hydrologic subbasin 17020011, at an elevation of about 2,120 feet, draining roughly 170 square miles.
- Can I use Chiwawa River near Plain, WA data for flood or safety decisions?
- No. Rivermatics provides estimates, not guarantees, and the readings and forecasts here may be delayed, inaccurate, or wrong. Do not use them for navigation or for any safety, rescue, or emergency decision. Check the National Weather Service and USGS directly, and use your own judgment.