Grand Coulee

HydroelectricWashingtonFirst unit online 1941

Grand Coulee is a hydroelectric plant in Grant County, Washington, operated by U S Bureau of Reclamation. By nameplate capacity it is the largest power plant in the United States. Among the 1,390 hydroelectric plants in the country it is the largest. Within the Bonneville Power Administration balancing area it is the largest of 129 plants.

Nameplate capacity, 2025

6,809 MW

7,079 MW net summer capacity

33 operable units

Hydro6,495 MW95%
Pumped-storage hydro314 MW4.6%

Unit by unit, 1941 to 2025

operating in 2025bar height follows unit size

3 units Hydro, 145 MW, 1941

2 units Hydro, 250 MW, 1942

3 units Hydro, 375 MW, 1943

Unit 4 Hydro, 125 MW, 1944

Unit 7 Hydro, 125 MW, 1947

Unit 9 Hydro, 125 MW, 1948

3 units Hydro, 375 MW, 1949

3 units Hydro, 375 MW, 1950

4 units Hydro, 385 MW, 1951

2 units Pumped-storage hydro, 100 MW, 1973

Unit 19 Hydro, 600 MW, 1975

2 units Hydro, 1,200 MW, 1976

Unit 22 Hydro, 805 MW, 1978

Unit 23 Hydro, 805 MW, 1979

Unit 24 Hydro, 805 MW, 1980

3 units Pumped-storage hydro, 160 MW, 1983

Unit PG12 Pumped-storage hydro, 53.5 MW, 1984

Among Washington’s plants

Largest plants in the state by nameplate capacity, with the plants ranked next to this one.

1Grand Couleethis plant
2Chief Joseph2,456 MW
3Rocky Reach1,349 MW

All power plants in Washington

Other rankings

Hydroelectric plants in Washington: 1st of 72
Plants run by U S Bureau of Reclamation: 1st of 57
Biggest single unit, among Washington’s plants: 2nd of 138

Operable units

Unit	Technology	Nameplate	Summer	Online	Status
LS1	Hydro	10 MW	10 MW	1941	Operating
LS2	Hydro	10 MW	10 MW	1941	Operating
3	Hydro	125 MW	125 MW	1941	Operating
2	Hydro	125 MW	125 MW	1942	Operating
1	Hydro	125 MW	125 MW	1942	Operating
8	Hydro	125 MW	125 MW	1943	Operating
6	Hydro	125 MW	125 MW	1943	Operating
5	Hydro	125 MW	125 MW	1943	Operating
4	Hydro	125 MW	125 MW	1944	Operating
7	Hydro	125 MW	125 MW	1947	Operating
9	Hydro	125 MW	125 MW	1948	Operating
18	Hydro	125 MW	125 MW	1949	Operating
17	Hydro	125 MW	125 MW	1949	Operating
16	Hydro	125 MW	125 MW	1949	Operating
15	Hydro	125 MW	125 MW	1950	Operating
14	Hydro	125 MW	125 MW	1950	Operating
13	Hydro	125 MW	125 MW	1950	Operating
LS3	Hydro	10 MW	10 MW	1951	Operating
12	Hydro	125 MW	125 MW	1951	Operating
11	Hydro	125 MW	125 MW	1951	Operating
10	Hydro	125 MW	125 MW	1951	Operating
PG7	Pumped-storage hydro	50 MW	50 MW	1973	Operating
PG8	Pumped-storage hydro	50 MW	50 MW	1973	Operating
19	Hydro	600 MW	690 MW	1975	Operating
20	Hydro	600 MW	690 MW	1976	Operating
21	Hydro	600 MW	690 MW	1976	Operating
22	Hydro	805 MW	805 MW	1978	Operating
23	Hydro	805 MW	805 MW	1979	Operating
24	Hydro	805 MW	805 MW	1980	Operating
PG9	Pumped-storage hydro	53.5 MW	53.5 MW	1983	Operating
PG10	Pumped-storage hydro	53.5 MW	53.5 MW	1983	Operating
PG11	Pumped-storage hydro	53.5 MW	53.5 MW	1983	Operating
PG12	Pumped-storage hydro	53.5 MW	53.5 MW	1984	Operating

Grid and site

Balancing area: Bonneville Power Administration
Reliability region: Western Electricity Coordinating Council
Highest grid connection voltage: 525 kV
Water source: Columbia River
Nearest town on record: Grand Coulee
Operator type: Utility
Coordinates: 47.958°N, 118.977°W

Closest plants

Plant	Runs on	Capacity	Distance
Main Canal Headworks	Hydroelectric	26.8 MW	27.9 mi southwest
Chief Joseph	Hydroelectric	2,456 MW	30.8 mi west
Summer Falls Power Plant	Hydroelectric	92 MW	34.7 mi southwest
Wells	Hydroelectric	867 MW	41.1 mi west
Chelan	Hydroelectric	59.2 MW	48.7 mi west
Little Falls (WA)	Hydroelectric	43.2 MW	50.0 mi east
Long Lake	Hydroelectric	70 MW	53.5 mi east
Kettle Falls Generating Station	Biomass and waste	57.9 MW	60.7 mi northeast

See every hydroelectric plant in Washington in the plant finder Hydroelectric plants nationwide