CHIEF JOSEPH
OperatingHydro power plant
- Capacity
- 2,456 MW
- Primary fuel
- Hydro
- County
- Douglas County
- Operator
- USACE NORTHWESTERN DIVISION
- Status
- Operating
- Commissioned
- 1955
- EIA plant ID
- 3921
- Generators
- 27
- Technology
- Conventional Hydroelectric
- Net generation (2024)
- 9,228 GWh
- Capacity factor (2024, EIA nameplate)
- 43%
- Data vintage
- EIA-860 2024 final; EIA-923 2022-2024 final
- Coordinates
- 47.9954, -119.6412
CHIEF JOSEPH, a 2,456 MW Hydro power plant in Douglas County, Washington. Operated by USACE NORTHWESTERN DIVISION, commissioned 1955.
How CHIEF JOSEPH compares
With 2,456 MW of capacity, CHIEF JOSEPH ranks 2nd among the 126 operating power plants Bywatts maps in Washington and 2nd of the 65 operating Hydro plants in the state. It accounts for about 12% of Washington's operating Hydro capacity and 8.1% of all operating capacity in the state. Nationally it is the 3rd-largest of the 1,243 operating Hydro plants in the database. Commissioned in 1955, it is older than 78% of the 125 operating Washington plants with a recorded commissioning year. Its operator, USACE NORTHWESTERN DIVISION, runs 5 operating plants in Washington totaling 5,489 MW.
EIA-860 lists 27 generators at the site with 2,456 MW of nameplate capacity, all conventional hydroelectric technology. Net generation was 9,228 GWh in 2024 (a 43% capacity factor), down 26% from 2022. Its generators came online between 1955 and 1979.
Grid neighborhood
The nearest named substation is FOSTER CREEK (115 kV), about 0.7 miles away; the closest transmission line found within 10 miles is a 115 kV line owned by PUD NO 1 OF DOUGLAS COUNTY, under 0.1 miles away. Another 2 operating power plants totaling 833 MW sit within 25 miles; the largest is WELLS (774 MW, Hydro).
Computed by Bywatts from HIFLD power plant, substation and transmission line records and EIA-860/923 survey data; distances are straight-line. Sources and methodology
Weather peril exposure
CHIEF JOSEPH is a 2,456 MW hydro power plant in Douglas County, WA, operated by USACE NORTHWESTERN DIVISION, commissioned in 1955. Douglas County carries low modeled catastrophe exposure in the FEMA National Risk Index, scoring 1.6 of 5 at the 14th national percentile. Riverine flooding is the leading peril, rated Relatively Moderate by FEMA at the 97th percentile.
The Bywatts loss layer is calibrated to solar PV hardware, so it is not applied to a hydro plant. The ratings below are the FEMA National Risk Index county hazard ratings for this location.
Douglas County hazard ratings
| Peril | FEMA rating | National percentile | Peril score | Events per year |
|---|---|---|---|---|
| Riverine flooding | Relatively Moderate | 97th | 4.9 of 5 | 0.32 |
| Wildfire | Relatively Moderate | 96th | 4.9 of 5 | 0.01 |
| Earthquake | Relatively Low | 86th | 4.4 of 5 | <0.01 |
| Heat wave | Relatively Low | 63rd | 3.5 of 5 | 4.4 |
| Winter weather | Relatively Low | 36th | 2.4 of 5 | 14.6 |
| Strong wind | Relatively Low | 9th | 1.3 of 5 | 0.11 |
| Lightning | Relatively Low | 7th | 1.3 of 5 | 11.5 |
| Tornado | Very Low | 4th | 1.2 of 5 | 0.05 |
| Hail | Relatively Low | 2nd | 1.1 of 5 | 0.11 |
| Ice storm | Very Low | 0th | 1.0 of 5 | 0.01 |
Perils not assessed in Douglas County
These perils carry no usable National Risk Index figure for this county, so they are excluded from the scoring rather than scored zero. A zero would claim the peril was assessed and found benign.
| Peril | Why it is not scored |
|---|---|
| Hurricane | FEMA rating is "Not Applicable" for this county |
| Coastal flooding | FEMA rating is "Not Applicable" for this county |
Model hail, wind and flood exposure for Douglas County in the weather risk calculator
Ratings are the FEMA National Risk Index county hazard ratings; the peril score is a Bywatts transform of the FEMA national percentile. Full data sources and the solar vulnerability methodology are in the weather risk calculator.
Modeled estimate for screening and negotiation. Built from FEMA National Risk Index county hazard data and a solar vulnerability layer documented above. Not a quote, a binder, or actuarial advice, and not a substitute for a carrier's own model. Hazard data: FEMA National Risk Index December 2025, synced 2026-07-24. Resolution is county level, not site level.