Largest Reservoirs in Massachusetts

Massachusetts has 1278 dams with recorded storage capacity. The largest is Quabbin Spillway with 1,810,000 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	Quabbin Spillway	Hampshire	1,810,000	10	Water Supply	1938
2	Quabbin Winsor Dam	Hampshire	1,810,000	170	Water Supply	1939
3	Quabbin Goodnough Dike	Hampshire	1,810,000	135	Water Supply	1938
4	Wachusett Reservoir South Dike	Worcester	250,000	45	Water Supply	1906
5	Wachusett Reservoir Dam	Worcester	250,000	114	Water Supply	1906
6	Wachusett Reservoir North Dike	Worcester	250,000	85	Water Supply	1904
7	Cobble Mountain Reservoir Dam	Hampden	97,200	245	Water Supply	1930
8	Birch Hill Dam - Winchenden Dike	Worcester	76,000	49	Flood Risk Reduction	1942
9	East Brimfield Dam	Worcester	71,000	53	Flood Risk Reduction	1960
10	Knightville Dam	Hampshire	64,000	150	Flood Risk Reduction	1941
11	Barre Falls Dam - Dike 3	Worcester	63,000	48	Flood Risk Reduction	1958
12	Barre Falls Dam - Dike 2	Worcester	63,000	38	Flood Risk Reduction	1958
13	Barre Falls Dam - Dike 1	Worcester	63,000	23	Flood Risk Reduction	1958
14	Barre Falls Dam	Worcester	63,000	69	Flood Risk Reduction	1958
15	Assawompset Pond Dam	Plymouth	62,000	7	Water Supply	1894
16	Tully Dam	Worcester	35,800	59	Flood Risk Reduction	1949
17	Sudbury Reservoir Dam	Worcester	33,020	77	Water Supply	1899
18	West Hill Dam - Dike D	Worcester	29,500	48	Flood Risk Reduction	1961
19	Otis Reservoir Dam	Berkshire	27,500	32	Recreation	1888
20	Quequechan Control Structure	Bristol	27,000	25	Flood Risk Reduction	1963
21	Holyoke - Overflow No. 2	Hampden	26,000	30	Hydroelectric	1860
22	Hodges Village Dam - Dike 1	Worcester	26,000	30	Flood Risk Reduction	1959
23	Tighe Carmody Reservoir Dam	Hampshire	25,490	130	Water Supply	1955
24	Westville Dam	Worcester	24,000	72	Flood Risk Reduction	1962
25	Cabot Station	Franklin	21,500	35	Hydroelectric	1916
26	Northfield Mt. - Main Dam	Franklin	21,500	145	Hydroelectric	1973
27	Great Stone	Essex	19,900	38	Hydroelectric	1848
28	Silver Lake Dam	Plymouth	16,558	8	Water Supply	1908
29	Webster Lake Dam	Worcester	14,904	15	Recreation	1957
30	Pine Hill Reservoir Dam	Worcester	13,023	70	Water Supply	1924
31	Buffumville Dam - Pierpoint Meadow Pond Dike	Worcester	12,700	18	Flood Risk Reduction	1958
32	North Watuppa Pond Dam	Bristol	12,625	11	Water Supply	1963
33	Copicut Reservoir Dam	Bristol	12,600	40	Water Supply	1971
34	Stockbridge Bowl Dam	Berkshire	11,000	19	Recreation	1880
35	Cambridge Reservoir Dam	Middlesex	10,380	31	Water Supply	1897
36	Ludlow Reservoir Dam	Hampden	9,100	19	Water Supply	1877
37	Cherry Valley Dam	Hampden	9,100	41	Water Supply	1877
38	Putnamville Reservoir West Dike	Essex	8,500	26	Water Supply	1954
39	Putnamville Reservoir East Dike	Essex	8,430	24	Water Supply	1954
40	Putnamville Reservoir Dam	Essex	8,370	37	Water Supply	1954
41	Putnamville Reservoir South Dike	Essex	8,370	7	Water Supply	1954
42	Lake Cochichewick Outlet Dam	Essex	8,100	13	Water Supply	1865
43	New Charles River Dam	Suffolk	7,820	36	Flood Risk Reduction	1978
44	Kenoza Lake Outlet Dam	Essex	7,805	10	Water Supply	1979
45	Spot Pond Dam	Middlesex	7,779	18	Water Supply	1880
46	Spot Pond Dike No. 5	Middlesex	7,779	10	Water Supply	1880
47	Spot Pond Dike No. 4	Middlesex	7,779	10	Water Supply	1880
48	Lake Shirley Dam	Worcester	7,719	21	Recreation	1852
49	Walden Pond Outlet Dam	Essex	6,900	43	Water Supply	1890
50	Hopkinton Reservoir Dam	Middlesex	6,850	58	Recreation	1891

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