Dam
|
County
|
River
|
Reservoir
|
Type
|
Installed capacity (MW)
|
Height
|
Reservoir capacity
|
Year
|
Owner
|
Primary purpose(s)
|
ft
|
m
|
acre.ft
|
dam3
|
Alder Dam
|
Pierce/ Thurston
|
Nisqually River
|
Alder Lake
|
Arch
|
50.0
|
330
|
100
|
241,950
|
298,440
|
1945
|
Tacoma Power
|
Hydroelectric
|
Bonneville Dam†
|
Skamania
|
Columbia River
|
Lake Bonneville
|
Gravity
|
1,242.0
|
197
|
60
|
537,000
|
662,000
|
1937
|
U.S. Army Corps of Engineers
|
Hydroelectric, Navigation
|
Boundary Dam
|
Pend Oreille
|
Pend Oreille River
|
Boundary Lake
|
Arch-gravity
|
1,070.0
|
340
|
100
|
95,000
|
117,000
|
1967
|
Seattle City Light
|
Hydroelectric
|
Box Canyon Dam
|
Pend Oreille
|
Pend Oreille River
|
Box Canyon Reservoir
|
Gravity
|
90.0
|
62
|
19
|
60,000
|
74,000
|
1956
|
Pend Oreille Public Utility District
|
Hydroelectric
|
Chief Joseph Dam
|
Douglas/ Okanogan
|
Columbia River
|
Rock Island Pool
|
Gravity
|
2,620.0
|
135
|
41
|
516,000
|
636,000
|
1979
|
U.S. Army Corps of Engineers
|
Hydroelectric
|
Cle Elum Dam
|
Kittitas
|
Cle Elum River
|
Cle Elum Lake[n 1]
|
Earthfill
|
|
165
|
50
|
436,900
|
538,900
|
1933
|
U.S. Bureau of Reclamation
|
Irrigation
|
Culmback Dam
|
Snohomish
|
Sultan River
|
Spada Lake
|
Rockfill
|
112.0
|
262
|
80
|
165,774
|
204,479
|
1965
|
City of Everett, Snohomish County PUD
|
Water supply
|
Cushman Dam No. 1
|
Mason
|
North Fork Skokomish River
|
Lake Cushman
|
Arch
|
43.2
|
235
|
72
|
453,400
|
559,300
|
1926
|
Tacoma Power
|
Hydroelectric
|
Cushman Dam No. 2
|
Mason
|
North Fork Skokomish River
|
Lake Kokanee
|
Arch
|
81.0
|
175
|
53
|
8,000
|
9,900
|
1930
|
Tacoma Power
|
Hydroelectric
|
Diablo Dam
|
Whatcom
|
Skagit River
|
Diablo Lake
|
Arch
|
129.0
|
389
|
119
|
88,500
|
109,200
|
1930
|
Seattle City Light
|
Hydroelectric
|
Dry Falls Dam[n 2]
|
Grant
|
Grand Coulee
|
Banks Lake
|
Earthfill
|
|
123
|
37
|
1,275,000
|
1,573,000
|
1949
|
U.S. Bureau of Reclamation
|
Irrigation
|
Gorge Dam
|
Whatcom
|
Skagit River
|
Gorge Lake
|
Gravity
|
199.2
|
300
|
91
|
9,700
|
12,000
|
1961
|
Seattle City Light
|
Hydroelectric
|
Grand Coulee Dam
|
Grant/ Okanogan
|
Columbia River
|
Franklin Delano Roosevelt Lake
|
Gravity
|
6,809.0
|
550
|
170
|
9,562,000
|
11,795,000
|
1942
|
U.S. Bureau of Reclamation
|
Irrigation, Hydroelectric, Flood control
|
Hiram M. Chittenden Locks and Dam
|
King
|
Lake Washington Ship Canal
|
Lake Washington[n 3]
|
Gravity
|
0
|
26
|
7.9
|
458,000
|
565,000
|
1916
|
U.S. Army Corps of Engineers
|
Navigation
|
Howard A. Hanson Dam
|
King
|
Green River
|
Howard A. Hanson Reservoir
|
Earthfill
|
|
235
|
72
|
136,700
|
168,600
|
1961
|
U.S. Army Corps of Engineers
|
Flood control, Water supply
|
John Day Dam†
|
Klickitat
|
Columbia River
|
Lake Umatilla
|
Gravity
|
2,160.0
|
184
|
56
|
2,530,000
|
3,120,000
|
1971
|
U.S. Army Corps of Engineers
|
Hydroelectric, Navigation
|
Ice Harbor Dam
|
Franklin/ Walla Walla
|
Snake River
|
Lake Sacajawea
|
Gravity
|
603.0
|
100
|
30
|
249,000
|
307,000
|
1962
|
U.S. Army Corps of Engineers
|
Hydroelectric, Navigation
|
Kachess Dam
|
Kittitas
|
Kachess River
|
Kachess Lake[n 4]
|
Earthfill
|
|
112
|
34
|
239,000
|
295,000
|
1912
|
U.S. Bureau of Reclamation
|
Irrigation
|
Keechelus Dam
|
Kittitas
|
Yakima River
|
Keechelus Lake[n 5]
|
Earthfill
|
|
128
|
39
|
157,900
|
194,800
|
1917
|
U.S. Bureau of Reclamation
|
Irrigation
|
LaGrande Dam
|
Pierce/ Thurston
|
Nisqually River
|
LaGrande Reservoir
|
Gravity
|
65.0
|
192
|
59
|
2,700
|
3,300
|
1945
|
Tacoma Power
|
Hydroelectric
|
Lake Chelan Dam
|
Chelan
|
Chelan River
|
Lake Chelan[n 6]
|
Gravity
|
59.2
|
40
|
12
|
677,400
|
835,600
|
1927
|
Chelan County Public Utility District
|
Hydroelectric
|
Lake Tapps (Multiple dikes)
|
Pierce
|
Off-stream
|
Lake Tapps
|
Earthfill
|
|
|
|
48,258
|
59,525
|
1911
|
Cascade Water Alliance
|
Recreation, Water supply (proposed)
|
Little Goose Dam
|
Columbia/ Whitman
|
Snake River
|
Lake Bryan
|
Gravity
|
810.0
|
96
|
29
|
516,300
|
636,800
|
1970
|
U.S. Army Corps of Engineers
|
Hydroelectric, Navigation
|
Long Lake Dam
|
Lincoln/ Stevens
|
Spokane River
|
Long Lake
|
Gravity
|
71.0
|
213
|
65
|
105,000
|
130,000
|
1915
|
Avista
|
Hydroelectric
|
Lower Baker Dam
|
Skagit
|
Baker River
|
Lake Shannon
|
Arch
|
79.0
|
285
|
87
|
161,470
|
199,170
|
1925
|
Puget Sound Energy
|
Hydroelectric
|
Lower Granite Dam
|
Garfield/ Whitman
|
Snake River
|
Lower Granite Lake
|
Gravity
|
810.0
|
100
|
30
|
440,200
|
543,000
|
1975
|
U.S. Army Corps of Engineers
|
Hydroelectric, Navigation
|
Lower Monumental Dam
|
Franklin/ Walla Walla
|
Snake River
|
Lake Herbert G. West
|
Gravity
|
810.0
|
100
|
30
|
432,000
|
533,000
|
1969
|
U.S. Army Corps of Engineers
|
Hydroelectric, Navigation
|
Masonry Dam
|
King
|
Cedar River
|
Chester Morse Lake/ Masonry Pool[n 7]
|
Arch-gravity
|
30.0
|
215
|
66
|
93,900
|
115,800
|
1915
|
Seattle Public Utilities
|
Water supply, Hydroelectric
|
Mayfield Dam
|
Lewis
|
Cowlitz River
|
Lake Mayfield
|
Arch-gravity
|
162.0
|
250
|
76
|
133,764
|
164,995
|
1963
|
Tacoma Power
|
Hydroelectric
|
McNary Dam†
|
Benton
|
Columbia River
|
Lake Wallula
|
Gravity
|
986.0
|
183
|
56
|
1,350,000
|
1,670,000
|
1954
|
U.S. Army Corps of Engineers
|
Hydroelectric, Navigation
|
Merwin Dam
|
Clark/ Cowlitz
|
Lewis River
|
Lake Merwin
|
Arch-gravity
|
136.0
|
313
|
95
|
422,000
|
521,000
|
1931
|
PacifiCorp
|
Hydroelectric
|
Mossyrock Dam
|
Lewis
|
Cowlitz River
|
Riffe Lake
|
Arch
|
300.0
|
606
|
185
|
1,685,000
|
2,078,000
|
1968
|
Tacoma Power
|
Hydroelectric
|
Mud Mountain Dam
|
King
|
White River
|
Mud Mountain Lake
|
Earth/rockfill
|
0
|
432
|
132
|
106,000
|
131,000
|
1948
|
U.S. Army Corps of Engineers
|
Flood control
|
Pinto Dam
|
Grant
|
Off-stream
|
Billy Clapp Lake
|
Earthfill
|
|
130
|
40
|
21,200
|
26,100
|
1948
|
U.S. Bureau of Reclamation
|
Irrigation
|
Priest Rapids Dam
|
Grant/ Yakima
|
Columbia River
|
Priest Rapids Lake
|
Gravity/ Embankment
|
955.6
|
178
|
54
|
237,100
|
292,500
|
1961
|
Grant County Public Utility District
|
Hydroelectric
|
Rock Island Dam
|
Chelan/ Douglas
|
Columbia River
|
Rock Island Pool
|
Gravity
|
623.7
|
135
|
41
|
131,000
|
162,000
|
1933
|
Chelan County Public Utility District
|
Hydroelectric
|
Rocky Reach Dam
|
Chelan/ Douglas
|
Columbia River
|
Lake Entiat
|
Gravity
|
1,299.6
|
130
|
40
|
382,000
|
471,000
|
1969
|
Chelan County Public Utility District
|
Hydroelectric
|
Ross Dam
|
Whatcom
|
Skagit River
|
Ross Lake
|
Arch
|
460.0
|
540
|
160
|
1,435,000
|
1,770,000
|
1949
|
Seattle City Light
|
Hydroelectric
|
Skookumchuck Dam
|
Thurston
|
Skookumchuck River
|
Skookumchuck Reservoir
|
Earthfill
|
1.0
|
190
|
58
|
34,800
|
42,900
|
1970
|
TransAlta
|
Water supply
|
South Fork Tolt River Dam
|
King
|
South Fork Tolt River
|
South Fork Tolt Reservoir
|
Earthfill
|
6.55
|
200
|
61
|
57,900
|
71,400
|
1964
|
Seattle Public Utilities
|
Water supply
|
Swift Dam
|
Skamania
|
Lewis River
|
Swift Reservoir
|
Earthfill
|
240.0
|
512
|
156
|
755,600
|
932,000
|
1958
|
PacifiCorp
|
Hydroelectric
|
The Dalles Dam†
|
Klickitat
|
Columbia River
|
Lake Celilo
|
Gravity
|
1,878.3
|
200
|
61
|
330,000
|
410,000
|
1957
|
U.S. Army Corps of Engineers
|
Hydroelectric, navigation
|
Tieton Dam
|
Yakima
|
Tieton River
|
Rimrock Lake
|
Earthfill
|
15.6
|
319
|
97
|
203,600
|
251,100
|
1925
|
U.S. Bureau of Reclamation
|
Irrigation
|
Toutle River Sediment Retention Structure
|
Cowlitz
|
North Fork Toutle River
|
[n 8]
|
Earthfill
|
0
|
184
|
56
|
160,000
|
200,000
|
1989
|
U.S. Army Corps of Engineers
|
Sediment control
|
Upper Baker Dam
|
Whatcom
|
Baker River
|
Baker Lake
|
Arch
|
91.0
|
312
|
95
|
285,000
|
352,000
|
1959
|
Puget Sound Energy
|
Hydroelectric
|
Wanapum Dam
|
Grant/ Kittitas
|
Columbia River
|
Lake Wanapum
|
Gravity/ Embankment
|
1,040.0
|
185
|
56
|
796,000
|
982,000
|
1963
|
Grant County Public Utility District
|
Hydroelectric
|
Wells Dam
|
Chelan/ Douglas
|
Columbia River
|
Lake Pateros
|
Gravity
|
851.4
|
160
|
49
|
331,200
|
408,500
|
1967
|
Douglas County Public Utility District
|
Hydroelectric
|
Wynoochee Dam
|
Grays Harbor
|
Wynoochee River
|
Wynoochee Lake
|
Gravity
|
10.8
|
175
|
53
|
69,405
|
85,610
|
1972
|
City of Aberdeen
|
Water supply
|
Yale Dam
|
Clark/ Cowlitz
|
Lewis River
|
Yale Lake
|
Earthfill
|
134.0
|
323
|
98
|
402,000
|
496,000
|
1953
|
PacifiCorp
|
Hydroelectric
|