Largest Reservoirs in Alaska

Alaska has 96 dams with recorded storage capacity. The largest is Blue Lake with 266,000 acre-feet of maximum storage. One acre-foot equals about 326,000 gallons — enough to supply roughly two households for a year.

#	Dam	County	Max Storage (acre-ft)	Height (ft)	Purpose	Year
1	Blue Lake	City and Borough of Sitka	266,000	294	Hydroelectric	1961
2	Eklutna Dam	Municipality of Anchorage	240,000	56	Hydroelectric	1965
3	Moose Creek Dam - East Cutoff Dike	Fairbanks North Star Borough	224,000	60	Flood Risk Reduction	1979
4	Long Lake Dam	City and Borough of Juneau	147,000	30	Hydroelectric	1973
5	Swan Lake	Ketchikan Gateway Borough	144,763	174	Hydroelectric	1984
6	Fort Knox Tailings Dam	Fairbanks North Star Borough	136,000	350	Water Supply	1996
7	Cooper Lake	Kenai Peninsula Borough	127,600	52	Hydroelectric	1959
8	Red Dog Tailings Main Dam	Northwest Arctic Borough	40,030	208	Tailings	1993
9	Upper Silvis	Ketchikan Gateway Borough	38,000	60	Hydroelectric	1968
10	Red Dog Tailings Back Dam	Northwest Arctic Borough	24,757	66	Other	2010
11	Annex Creek	City and Borough of Juneau	23,400	20	Hydroelectric	1968
12	Salmon Creek	City and Borough of Juneau	18,000	175	Hydroelectric	1914
13	Ketchikan Lakes	Ketchikan Gateway Borough	13,300	34	Hydroelectric	1957
14	Eyak Lake	Chugach Census Area	13,000	15	Fish and Wildlife Pond	1972
15	Lake Connell	Ketchikan Gateway Borough	11,000	96	Water Supply	1953
16	Hess Creek Dam	Yukon-Koyukuk Census Area	10,200	56	Water Supply	1946
17	Crystal Lake	Petersburg Borough	5,800	43	Hydroelectric	1955
18	Fort Knox Water Dam	Fairbanks North Star Borough	5,350	70	Water Supply	1995
19	Monashka Creek Dam	Kodiak Island Borough	3,850	58	Water Supply	1982
20	Monashka Creek Dike	Kodiak Island Borough	3,850	45	Water Supply	1982
21	Lower Slate Lake Tailings Dam	City and Borough of Juneau	2,800	63	Tailings	2010
22	Bonnie Rose Lake Dam	Aleutians West Census Area	2,260	15	Water Supply	1943
23	Lake Demarie Dam	Aleutians West Census Area	2,120	19	Water Supply	1951
24	Lake Lucile Dam	Matanuska-Susitna Borough	2,051	6	Fish and Wildlife Pond	1969
25	Cannery Creek Dam	Chugach Census Area	2,000	17	Other	1979
26	Chester Lake	Prince of Wales-Hyder Census Area	1,961	35	Water Supply	1986
27	Big Kitoi	Kodiak Island Borough	1,800	9	Water Supply	1962
28	Lake Leone Dam	Aleutians West Census Area	1,690	9	Water Supply	1945
29	Lower Silvis	Ketchikan Gateway Borough	1,600	32	Hydroelectric	1954
30	Bluff Lake Diversion	Ketchikan Gateway Borough	1,450	10	Hydroelectric	1984
31	Itasigrook	North Slope Borough	1,300	13	Water Supply	1964
32	Cabin Creek Dam	Petersburg Borough	1,270	38	Water Supply	1996
33	Lake Osprey Dam	City and Borough of Sitka	1,250	8	Water Supply	1919
34	Isatkuag Lagoon Dam	North Slope Borough	1,140	16	Water Supply	1977
35	North Fork Lake Dam	Prince of Wales-Hyder Census Area	1,136	12	Water Supply
36	Bridge Creek Dam	Kenai Peninsula Borough	943	65	Water Supply	1975
37	Campbell Lake Dam	Municipality of Anchorage	800	11	Debris Control	1957
38	Carlanna Lake	Ketchikan Gateway Borough	700	31	Water Supply	1975
39	Red Dog Water Supply Dam	Northwest Arctic Borough	684	75	Water Supply	1989
40	Lower Dewey	Municipality of Skagway	650	28	Hydroelectric	1905
41	Lower Fire Lake Dam	Municipality of Anchorage	550	13	Fish and Wildlife Pond	1960
42	A F K Hatchery Dam	Chugach Census Area	533	32	Water Supply	1977
43	Kotzebue Water Supply Dam	Northwest Arctic Borough	412	16	Water Supply	1970
44	Mahoona Dam	Kodiak Island Borough	400	13	Hydroelectric	1986
45	Gregory Lake	Municipality of Anchorage	375	16	Recreation
46	Westchester Lagoon Dam	Municipality of Anchorage	300	22	Recreation	1973
47	Shotgun Creek Div	Kodiak Island Borough	285	40	Hydroelectric	1984
48	Icy Lake Dam	Aleutians West Census Area	238	7	Water Supply	1995
49	Sherwood Estates Dam	Matanuska-Susitna Borough	200	20	Recreation	1975
50	C. P. P. Dam	Matanuska-Susitna Borough	197	7	Other

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