TWIN RESERVOIRS
OperatingHydro power plant
- Capacity
- 2 MW
- Primary fuel
- Hydro
- County
- Walla Walla County
- Operator
- WALLA WALLA CITY OF
- Status
- Operating
- Commissioned
- 1988
- EIA plant ID
- 50382
- Coordinates
- 46.0882, -118.2555
TWIN RESERVOIRS, a 2 MW Hydro power plant in Walla Walla County, Washington. Operated by WALLA WALLA CITY OF, commissioned 1988.
Weather peril exposure
TWIN RESERVOIRS is a 2 MW hydro power plant in Walla Walla County, WA, operated by WALLA WALLA CITY OF, commissioned in 1988. Walla Walla County carries low modeled catastrophe exposure in the FEMA National Risk Index, scoring 1.0 of 5 at the 1st national percentile. Earthquake is the leading peril, rated Relatively Moderate by FEMA at the 90th 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.
Walla Walla County hazard ratings
| Peril | FEMA rating | National percentile | Peril score | Events per year |
|---|---|---|---|---|
| Earthquake | Relatively Moderate | 90th | 4.6 of 5 | <0.01 |
| Wildfire | Relatively Low | 76th | 4.1 of 5 | <0.01 |
| Heat wave | Relatively Moderate | 67th | 3.7 of 5 | 7.2 |
| Riverine flooding | Relatively Low | 48th | 2.9 of 5 | 0.61 |
| Strong wind | Relatively Low | 26th | 2.0 of 5 | 0.33 |
| Lightning | Relatively Low | 9th | 1.3 of 5 | 10.5 |
| Hail | Relatively Low | 9th | 1.3 of 5 | 0.32 |
| Ice storm | Relatively High | 6th | 1.2 of 5 | 0.54 |
| Winter weather | Relatively Moderate | 6th | 1.2 of 5 | 9.2 |
| Tornado | Very Low | 6th | 1.2 of 5 | 0.04 |
Perils not assessed in Walla Walla 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 Walla Walla 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.