South Fork Tolt
Hydro power plant · King County, Washington
Nameplate capacity
17 MW
Rank in Washington
#90
of 139 plants
In service since
1995
November 1995
Details
- Primary fuel
- Hydro
- Technology
- Conventional Hydroelectric
- Operator
- City of Seattle - (WA)
- County
- King County
- Generating units
- 1
- Share of state capacity
- 0.05%
- Rank among hydro plants in Washington
- #43 of 73
- EIA plant code
- 622
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| 1 | Conventional Hydroelectric | 17 MW | 17 MW | 1995 | Operating |
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
| Sierra Pacific Aberdeen | Other | 18 MW |
| Upriver Dam Hydro Plant | Hydro | 18 MW |
| Cosmo Specialty Fibers Plant | Other | 15 MW |
| University of Washington Power Plant | Natural gas | 15 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 17 MW solar plant and a 17 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