, the U.S. state of Washington has 1,242 dams that are able to impound 10 acre-feet or more of water and are regulated by the Washington State Department of Ecology (DOE). These include dams that produce hydroelectricity and create reservoirs for irrigation, drinking water, or recreational uses. According to the DOE, approximately 52 percent of dams in the state are privately owned, while 31 percent are owned by local governments.
Approximately 87 percent of dams in Washington are earth fill dams, with the second most-common type being concrete gravity dams (6%). Only 113 dams in the state are taller than . King County has 123 dams—the most of any county in the state. The majority of dams were built between 1960 and 1999. Proposals to remove underused dams and restore fish habitats emerged in the early 21st century with support from the state's Native American tribes; the first major dam removal was the Condit Dam near White Salmon in 2011, which was followed by two dams on the Elwha River near Port Angeles. , 39 dams in Washington have been removed.
The largest dam in Washington, in terms of structural volume, reservoir capacity, and electricity production, is the Grand Coulee Dam on the Columbia River. It is the largest power station in the United States with a nameplate capacity of 6,809 megawatts and one of the largest concrete structures in the world. The tallest dam is Mossyrock Dam on the Cowlitz River in Lewis County, at . The longest dam is O'Sullivan Dam on Crab Creek, at ; it is among the longest earth fill dams in the United States.
List
+Key Located on state border with Oregon
+Dams and reservoirs in Washington over DamCountyRiverReservoirTypeInstalledcapacity(MW)HeightReservoircapacityYearOwnerPrimarypurpose(s)ftmacre.ftdam3Alder DamPierce/ThurstonNisqually RiverAlder LakeArch1945Tacoma PowerHydroelectricBonneville Dam†SkamaniaColumbia RiverLake BonnevilleGravity1937U.S. Army Corps of EngineersHydroelectric,NavigationBoundary DamPend OreillePend Oreille RiverBoundary LakeArch-gravity1967Seattle City LightHydroelectricBox Canyon DamPend OreillePend Oreille RiverBox Canyon ReservoirGravity1956Pend Oreille Public Utility DistrictHydroelectricChief Joseph DamDouglas/OkanoganColumbia RiverRock Island PoolGravity1979U.S. Army Corps of EngineersHydroelectricCle Elum DamKittitasCle Elum RiverCle Elum LakeEarthfill1933U.S. Bureau of ReclamationIrrigationCulmback DamSnohomishSultan RiverSpada LakeRockfill1965City of Everett, Snohomish County PUDWater supplyCushman Dam No. 1MasonNorth Fork Skokomish RiverLake CushmanArch1926Tacoma PowerHydroelectricCushman Dam No. 2MasonNorth Fork Skokomish RiverLake KokaneeArch1930Tacoma PowerHydroelectricDiablo DamWhatcomSkagit RiverDiablo LakeArch1930Seattle City LightHydroelectricDry Falls DamGrantGrand CouleeBanks LakeEarthfill1949U.S. Bureau of ReclamationIrrigationGorge DamWhatcomSkagit RiverGorge LakeGravity1961Seattle City LightHydroelectricGrand Coulee DamGrant/OkanoganColumbia RiverFranklin Delano Roosevelt LakeGravity1942U.S. Bureau of ReclamationIrrigation,Hydroelectric,Flood controlHiram M. Chittenden Locks and DamKingLake Washington Ship CanalLake WashingtonGravity01916U.S. Army Corps of EngineersNavigationHoward A. Hanson DamKingGreen RiverHoward A. Hanson ReservoirEarthfill1961U.S. Army Corps of EngineersFlood control,Water supplyJohn Day Dam†KlickitatColumbia RiverLake UmatillaGravity1971U.S. Army Corps of EngineersHydroelectric,NavigationIce Harbor DamFranklin/Walla WallaSnake RiverLake SacajaweaGravity1962U.S. Army Corps of EngineersHydroelectric,NavigationKachess DamKittitasKachess RiverKachess LakeEarthfill1912U.S. Bureau of ReclamationIrrigationKeechelus DamKittitasYakima RiverKeechelus LakeEarthfill1917U.S. Bureau of ReclamationIrrigationLaGrande DamPierce/ThurstonNisqually RiverLaGrande ReservoirGravity1945Tacoma PowerHydroelectricLake Chelan DamChelanChelan RiverLake ChelanGravity1927Chelan County Public Utility DistrictHydroelectricLake Tapps (Multiple dikes)PierceOff-streamLake TappsEarthfill1911Cascade Water AllianceRecreation,Water supply (proposed)Little Goose DamColumbia/WhitmanSnake RiverLake BryanGravity1970U.S. Army Corps of EngineersHydroelectric,NavigationLong Lake DamLincoln/StevensSpokane RiverLong LakeGravity1915AvistaHydroelectricLower Baker DamSkagitBaker RiverLake ShannonArch1925Puget Sound EnergyHydroelectricLower Granite DamGarfield/WhitmanSnake RiverLower Granite LakeGravity1975U.S. Army Corps of EngineersHydroelectric,NavigationLower Monumental DamFranklin/Walla WallaSnake RiverLake Herbert G. WestGravity1969U.S. Army Corps of EngineersHydroelectric,NavigationMasonry DamKingCedar RiverChester Morse Lake/Masonry PoolArch-gravity1915Seattle Public UtilitiesWater supply,HydroelectricMayfield DamLewisCowlitz RiverLake MayfieldArch-gravity1963Tacoma PowerHydroelectricMcNary Dam†BentonColumbia RiverLake WallulaGravity1954U.S. Army Corps of EngineersHydroelectric,NavigationMerwin DamClark/CowlitzLewis RiverLake MerwinArch-gravity1931PacifiCorpHydroelectricMossyrock DamLewisCowlitz RiverRiffe LakeArch1968Tacoma PowerHydroelectricMud Mountain DamKingWhite RiverMud Mountain LakeEarth/rockfill01948U.S. Army Corps of EngineersFlood controlPinto DamGrantOff-streamBilly Clapp LakeEarthfill1948U.S. Bureau of ReclamationIrrigationPriest Rapids DamGrant/YakimaColumbia RiverPriest Rapids LakeGravity/Embankment1961Grant County Public Utility DistrictHydroelectricRock Island DamChelan/DouglasColumbia RiverRock Island PoolGravity1933Chelan County Public Utility DistrictHydroelectricRocky Reach DamChelan/DouglasColumbia RiverLake EntiatGravity1969Chelan County Public Utility DistrictHydroelectricRoss DamWhatcomSkagit RiverRoss LakeArch1949Seattle City LightHydroelectricRoza DamKittitasYakima RiverYakima RiverGravity67201939United States Bureau of ReclamationIrrigationSkookumchuck DamThurstonSkookumchuck RiverSkookumchuck ReservoirEarthfill1970TransAltaWater supplySouth Fork Tolt River DamKingSouth Fork Tolt RiverSouth Fork Tolt ReservoirEarthfill1964Seattle Public UtilitiesWater supplySwift DamSkamaniaLewis RiverSwift ReservoirEarthfill1958PacifiCorpHydroelectricThe Dalles Dam†KlickitatColumbia RiverLake CeliloGravity1957U.S. Army Corps of EngineersHydroelectric,navigationTieton DamYakimaTieton RiverRimrock LakeEarthfill1925U.S. Bureau of ReclamationIrrigationToutle River Sediment Retention StructureCowlitzNorth Fork Toutle RiverEarthfill01989U.S. Army Corps of EngineersSediment controlUpper Baker DamWhatcomBaker RiverBaker LakeArch1959Puget Sound EnergyHydroelectricWanapum DamGrant/KittitasColumbia RiverLake WanapumGravity/Embankment1963Grant County Public Utility DistrictHydroelectricWells DamChelan/DouglasColumbia RiverLake PaterosGravity1967Douglas County Public Utility DistrictHydroelectricWynoochee DamGrays HarborWynoochee RiverWynoochee LakeGravity1972City of AberdeenWater supplyYale DamClark/CowlitzLewis RiverYale LakeEarthfill1953PacifiCorpHydroelectric
Removed dams Condit Dam, on the White Salmon River in Klickitat County Elwha Dam and Glines Canyon Dam, on the Elwha River in Clallam County
See also List of dams in the Columbia River watershed List of hydroelectric power stations in Washington
Notes
References
External links Washington State Dams map