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Ice Harbor

Hydro power plant · Walla Walla County, Washington

Nameplate capacity
603 MW
Rank in Washington
#15
of 139 plants
In service since
1962
January 1962

Details

Primary fuel
Hydro
Technology
Conventional Hydroelectric
Operator
USACE Northwestern Division
County
Walla Walla County
Generating units
6
Share of state capacity
1.90%
Rank among hydro plants in Washington
#12 of 73
EIA plant code
3925

Generating units

Individual generating units at Ice Harbor
UnitTechnologyNameplateSummerOnlineStatus
4Conventional Hydroelectric111 MW87 MW1975Operating
5Conventional Hydroelectric111 MW87 MW1975Operating
6Conventional Hydroelectric111 MW87 MW1976Operating
1Conventional Hydroelectric90 MW72 MW1962Out of service but expected to return to service in next calendar year
2Conventional Hydroelectric90 MW90 MW1962Operating
3Conventional Hydroelectric90 MW90 MW1962Out of service but expected to return to service in next calendar year

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

Grays Harbor Energy FacilityNatural gas715 MW
Rock IslandHydro629 MW
Chehalis Generating FacilityNatural gas593 MW
RossHydro450 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 603 MW solar plant and a 603 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