Rocky Brook Hydroelectric
Hydro power plant · Jefferson County, Washington
Nameplate capacity
1.6 MW
Rank in Washington
#133
of 139 plants
In service since
1985
December 1985
Details
- Primary fuel
- Hydro
- Technology
- Conventional Hydroelectric
- Operator
- Rocky Brook Electric Inc
- County
- Jefferson County
- Generating units
- 1
- Share of state capacity
- 0.01%
- Rank among hydro plants in Washington
- #69 of 73
- EIA plant code
- 50228
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| GEN1 | Conventional Hydroelectric | 1.6 MW | 0.1 MW | 1985 | Standby/Backup: available for service but not normally used |
Nameplate is the maximum rated output; summer capacity is what the unit can reliably deliver on a hot day, which is typically lower.
Similarly sized plants in Washington
| Drop 3 (WA) | Hydro | 1.6 MW |
| Orchard Avenue 1 | Hydro | 1.6 MW |
| Sheep Creek Hydro | Hydro | 1.6 MW |
| Arlington Microgrid | Battery storage | 1.5 MW |
About this data
From EIA’s inventory of operable generators, May 2026 release. Capacity is nameplate — the maximum rated output of the equipment, not what the plant actually generates over a year, which depends on how often it runs. A 1.6 MW solar plant and a 1.6 MW nuclear plant have the same entry here and produce very different amounts of electricity.
“In service since” is the earliest in-service date among the units still listed, so a site rebuilt around newer equipment can read as younger than the site itself. All Washington power plants · What Washington actually generates