ROCKY BROOK HYDROELECTRIC
OperatingHydro power plant
- Capacity
- 2 MW
- Primary fuel
- Hydro
- County
- Jefferson County
- Operator
- ROCKY BROOK ELECTRIC INC
- Status
- Operating
- Commissioned
- 1985
- EIA plant ID
- 50228
- Coordinates
- 47.7194, -122.9431
ROCKY BROOK HYDROELECTRIC, a 2 MW Hydro power plant in Jefferson County, Washington. Operated by ROCKY BROOK ELECTRIC INC, commissioned 1985.
Weather peril exposure
ROCKY BROOK HYDROELECTRIC is a 2 MW hydro power plant in Jefferson County, WA, operated by ROCKY BROOK ELECTRIC INC, commissioned in 1985. Jefferson County carries low modeled catastrophe exposure in the FEMA National Risk Index, scoring 1.5 of 5 at the 13th national percentile. Earthquake 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.
Jefferson County hazard ratings
| Peril | FEMA rating | National percentile | Peril score | Events per year |
|---|---|---|---|---|
| Earthquake | Relatively Moderate | 97th | 4.9 of 5 | 0.03 |
| Coastal flooding | Relatively Moderate | 89th | 4.6 of 5 | 3.4 |
| Winter weather | Relatively Moderate | 73rd | 3.9 of 5 | 16.0 |
| Heat wave | Very Low | 36th | 2.4 of 5 | 1.4 |
| Riverine flooding | Relatively Low | 32nd | 2.3 of 5 | 0.14 |
| Wildfire | Very Low | 28th | 2.1 of 5 | <0.01 |
| Ice storm | Relatively Moderate | 23rd | 1.9 of 5 | 0.19 |
| Tornado | Very Low | 5th | 1.2 of 5 | 0.04 |
| Lightning | Very Low | 4th | 1.1 of 5 | 4.0 |
| Hail | Very Low | 2nd | 1.1 of 5 | <0.01 |
| Strong wind | Very Low | 1st | 1.0 of 5 | <0.01 |
Perils not assessed in Jefferson 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 |
Model hail, wind and flood exposure for Jefferson 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.