Largest Reservoirs in Illinois

Illinois has 1570 dams with recorded storage capacity. The largest is Shelbyville Dam with 1,026,546 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	Shelbyville Dam	Shelby	1,026,546	138	Flood Risk Reduction	1970
2	Chicago River And Harbor Controlling Works	Cook	1,000,000	31	Navigation	1938
3	Smithland Locks And Dam	Livingston	738,700	56	Navigation	1980
4	Olmsted Locks And Dam	Ballard	728,000	67	Navigation	2018
5	Rend Dam	Franklin	607,910	54	Flood Risk Reduction	1971
6	Mississippi River Lock And Dam 19	Lee	292,000	63	Navigation	1913
7	Crab Orchard Dam	Williamson	254,000	65	Fish and Wildlife Pond	1939
8	Clinton Power Station/clinton Lake Dam	De Witt	250,000	65	Recreation	1977
9	Melvin Price Locks And Dam	St. Charles	238,000	77	Navigation	1990
10	Carlyle Dam - Saddle Dam 2	Clinton	233,000	22	Flood Risk Reduction	1966
11	Peoria Lock And Dam	Tazewell	225,000	23	Navigation	1939
12	Kinkaid Lake Dam	Jackson	153,000	96	Recreation	1972
13	Stratton Lock And Dam	McHenry	113,000	7	Flood Risk Reduction	1939
14	Spaulding Dam	Sangamon	101,205	48	Recreation	1933
15	Lake Of Egypt Dam	Williamson	82,942	55	Other	1962
16	Duck Creek Station Dams	Fulton	78,140	123	Other	1975
17	Sangchris Lake Dam	Christian	73,000	55	Recreation	1967
18	Lake Decatur Dam	Macon	57,520	33	Recreation	1922
19	Lagrange Lock And Dam	Brown	55,000	21	Navigation	1939
20	Newton Power Station Lake Dam	Jasper	49,600	54	Recreation	1975
21	Cedar Lake Dam	Jackson	49,336	74	Recreation	1974
22	Lake Lou Yaeger Dam	Montgomery	44,430	54	Recreation	1966
23	Lasalle Co. Nuclear Station Cooling Lake Dam	LaSalle	44,167	43	Other	1977
24	Mill Creek Structure 1 Dam	Clark	40,300	81	Flood Risk Reduction	1980
25	Lake Glenn Shoals Dam	Montgomery	38,900	56	Flood Risk Reduction	1978
26	Baldwin Plant Cooling Lake Dam	Randolph	36,341	55	Other	1968
27	Baldwin Plant Cooling Lake Dikes	St. Clair	36,341	55	Other	1968
28	Coffeen Lake Dam	Montgomery	35,800	70	Other	1964
29	Braidwood Station Cooling Pond Dam	Will	35,000	22	Other	1979
30	Devil`s Kitchen Dam	Williamson	34,500	121	Fish and Wildlife Pond	1959
31	Little Grassy Dam	Williamson	30,900	88	Fish and Wildlife Pond	1942
32	Moline Power	Rock Island	30,000	31	Hydroelectric	1896
33	Arsenal Power	Rock Island	30,000	29	Hydroelectric	1878
34	Collins Station Cooling Lake Dam	Grundy	29,600	27	Other	1975
35	Lake Taylorville Dam	Christian	28,500	27	Recreation	1961
36	Powerton Cooling Lake Dam	Tazewell	25,630	26	Other	1970
37	Sugar Camp/mine 1/north Refuse Disposal Facility Dam	Franklin	25,431	117	Tailings
38	Jerry F. Costello Lock And Dam	Randolph	25,246	81	Navigation	1974
39	Lockport Lock And Controlling Works	Will	25,000	65	Navigation	1933
40	Otter Lake Dam	Macoupin	24,708	71	Recreation	1969
41	Algonquin Dam	McHenry	24,200	9	Flood Risk Reduction	1947
42	Evergreen Lake Dam	Woodford	22,875	69	Water Supply	1971
43	East Fork Lake Dam	Richland	22,680	84	Recreation	1972
44	Lake Mattoon Dam	Shelby	22,569	46	Recreation	1957
45	Greenville New City Dam	Bond	22,400	40	Recreation	1969
46	Leroy Hinkle Dam	Carroll	22,169	74	Recreation	1974
47	Lake Sara Dam	Effingham	20,392	65	Recreation	1957
48	Spoon Lake Dam	Knox	19,500	74	Recreation	1971
49	Lake Bloomington Dam	McLean	17,806	51	Water Supply	1930
50	Busse Woods Reservoir South Dam	Cook	17,621	23	Flood Risk Reduction	1977

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