Reservoirs in Wisconsin

205 of 388 graded Wisconsin lakes (53%) are man-made reservoirs in the USACE National Inventory of Dams. 162 carry a High or Significant hazard rating.

Why these Wisconsin reservoirs were built

133

Recreation

Flood Risk Reduction

Water Supply

Other

Fish and Wildlife Pond

Hydroelectric

205

Total reservoirs

463,517

Total surface acres

16,975,069

Normal storage (ac-ft)

162

High or Significant hazard

All 205 Wisconsin reservoirs (by surface area)

Reservoir	County	Grade	Surface area	Year built	Purpose	Hazard
H.S. Truman Res. Nr. Dam Lake	Benton	C	55,600 ac	1979	Flood Risk Reduction	High
Loto Upstream of Dam Lake	Miller	B	55,342 ac	1931	Hydroelectric	High
Loto Lake	Miller	B	55,342 ac	1931	Hydroelectric	High
Table Rock Lake	Taney	B	43,100 ac	1959	Flood Risk Reduction	High
Table Rock Lk. Into Main Channel From Dam Lake	Stone	B	43,100 ac	1959	Flood Risk Reduction	High
Stockton Lake by Dam	Cedar	B	24,900 ac	1969	Flood Risk Reduction	High
Stockton Lake	Cedar	B	24,900 ac	1969	Flood Risk Reduction	High
Stockton Lake	Cedar	A	24,900 ac	1969	Flood Risk Reduction	High
Lake Wappapello Nr. Dam	Wayne	D	23,200 ac	1941	Flood Risk Reduction	High
Pomme de Terre L. Lake	Hickory	C	7,820 ac	1961	Flood Risk Reduction	High
Pomme de Terre Lake	Hickory	F	7,820 ac	1961	Flood Risk Reduction	High
Pomme de Terre L. Lake	Hickory	D	7,820 ac	1961	Flood Risk Reduction	High
Pomme de Terre Lake	Hickory	F	7,820 ac	1961	Flood Risk Reduction	High
Pomme de Terre Lake	Hickory	D	7,820 ac	1961	Flood Risk Reduction	High
Smithville Lake	Clay	D	7,190 ac	1979	Flood Risk Reduction	High
Smithville Lake by Dam	Clay	D	7,190 ac	1979	Flood Risk Reduction	High
Smithville Lake	Clay	D	7,190 ac	1979	Flood Risk Reduction	High
Mark Twain Lake by Hwy J	Ralls	C	5,900 ac	1983	Flood Risk Reduction	High
Mark Twain Lake	Ralls	D	5,900 ac	1983	Flood Risk Reduction	High
Thomas Hill Res. Nr. Dam Lake	Randolph	D	3,500 ac	1966	Flood Risk Reduction	High
Long Branch Lk. Lake	Macon	D	2,430 ac	1978	Flood Risk Reduction	High
Long Branch L. Lake	Macon	C	2,430 ac	1978	Flood Risk Reduction	High
Montrose Lake	Henry	F	1,700 ac	1955	Recreation	Low
Clearwater Lake Nr. Dam	Wayne	B	1,630 ac	1942	Flood Risk Reduction	High
Clearwater Lake	Reynolds	C	1,630 ac	1942	Flood Risk Reduction	High
Clearwater Lake	Reynolds	C	1,630 ac	1942	Flood Risk Reduction	High
Jacomo Lake	Jackson	C	1,221 ac	1956	Recreation	High
Mozingo Lake Between Arms	Nodaway	C	1,009 ac	1992	Water Supply	High
Mozingo Lake	Nodaway	F	1,009 ac	1992	Water Supply	High
Southern Mozingo Rservoir Lake	Nodaway	C	1,009 ac	1992	Water Supply	High
Longview Lake by Dam	Jackson	C	930 ac	1985	Flood Risk Reduction	High
Longview L. Nr. Dam Lake	Jackson	D	930 ac	1985	Flood Risk Reduction	High
Fellows Lake	Greene	B	812 ac	1955	Water Supply	High
Blue Springs L. Nr. Dam Lake	Jackson	D	722 ac	1988	Flood Risk Reduction	High
Forest Lake	Adair	B	646 ac	1951	Recreation	High
Lake St. Louis by Dam	St. Charles	F	563 ac	1973	Recreation	High
Lake St. Louis	St. Charles	D	563 ac	1973	Recreation	High
Hazel Creek Lk. Lake	Adair	C	515 ac	1982	Recreation	Significant
Hazel Creek Lk. Lake	Adair	C	515 ac	1982	Recreation	Significant
Lotawana Lk. Lake	Jackson	C	480 ac	1928	Recreation	High
Raintree Lake	Cass	F	475 ac	1974	Recreation	High
Harrisonville Lake	Cass	F	398 ac	1971	Recreation	High
Holden City Lake Nr. Dam	Johnson	F	380 ac	1980	Recreation	High
Goose Creek Lake	Ste. Genevieve	A	379 ac	1986	Recreation	High
Lake Springfield	Greene	D	360 ac	1956	Water Supply	High
Atkinson Lake by Sw 1401 Rd	St. Clair	D	355 ac	1962	Recreation	Low
Indian Hills Lake Nr. Dam	Crawford	D	355 ac	1960	Recreation	Low
Alpine Lake	Warren	A	325 ac	2000	Recreation	High
Sugar Creek Lake	Randolph	D	323 ac	1957	Water Supply	Low
Sugar Creek Lake	Randolph	D	323 ac	1957	Water Supply	Low
Prairie Lee Lake Nr. Dam	Jackson	D	300 ac	1939	Recreation	High
Harrison County Lake Intake	Harrison	D	292 ac	1992	Flood Risk Reduction	High
Harrison County Lake	Harrison	F	292 ac	1992	Flood Risk Reduction	High
Edwin A Pape Lake	Lafayette	F	284 ac	1967	Water Supply	Low
Lake Paho	Mercer	D	269.1 ac	1951	Recreation	High
Lake Nehai Tonkayea	Chariton	B	250 ac	1970	Recreation	Low
Hunnewell Lake	Shelby	D	228 ac	1953	Recreation	Significant
Elmwood Lake	Sullivan	F	224 ac	1972	Water Supply	High
Hemitite Lake	St. Francois	F	220 ac	1944	Water Supply	Low
Macon City Lake	Macon	D	205 ac	1927	Water Supply	High
Sunnen Lake	Washington	D	198 ac	1948	Recreation	High
Little Dixie Lk. Lake	Callaway	F	196 ac	1958	Recreation	High
Indian Creek Lake	Livingston	D	192 ac	1988	Recreation	High
Port Perry Lake	Perry	A	187 ac	1973	Recreation	High
Port Perry Lake South Arm	Perry	B	187 ac	1973	Recreation	High
Weatherby Lake	Platte	B	186 ac	1936	Recreation	High
King Lake	DeKalb	F	184 ac	1971	Flood Risk Reduction	High
Dc Rogers Lake Nr. Dam	Howard	D	184 ac	1970	Water Supply	High
Cameron Lake Nr. Dam	DeKalb	F	177 ac	1990	Water Supply	Low
Marceline City Lake New Nr. Dam	Chariton	C	177 ac	1980	Water Supply	High
Peaceful Valley Lake	Gasconade	C	164 ac	1965	Recreation	High
Peaceful Valley Lake	Gasconade	C	164 ac	1965	Recreation	High
Pony Express Lake	DeKalb	D	164 ac	1963	Recreation	High
Henry Sever Lake	Knox	D	160 ac	1961	Recreation	High
Callaway Fork Lake	St. Charles	D	154 ac	1981	Recreation	High
Higginsville South Lake	Lafayette	F	151 ac	1949	Water Supply	Low
Lamar City Lk. Nr. Dam Lake	Barton	F	150 ac	1955	Recreation	High
Lamar City Lk. South Arm Lake	Barton	F	150 ac	1955	Recreation	High
Aspen Lake Along Southern Arm	Warren	C	146 ac	1979	Recreation	High
Sherwood Lake Nr. Dam	Warren	B	145 ac	1967	Recreation	High
Sherwood Lake	Warren	B	145 ac	1967	Recreation	High
Binder Lake	Cole	D	138 ac	1966	Recreation	High
Spring Fork Lake	Pettis	F	128 ac	1925	Water Supply	High
Lake Tishomingo Nr. Dam	Jefferson	C	120 ac	1950	Recreation	High
Lake Capri	St. Francois	A	112 ac	1972	Recreation	High
Bilby Ranch Lake	Nodaway	D	110 ac	1991	Fish and Wildlife Pond	Low
Peters Lake	Howard	D	107 ac	1961	Recreation	High
Brookfield Lake	Linn	B	106 ac	1959	Water Supply	High
Little Prairie Lake by Dam	Phelps	C	100 ac	1965	Recreation	High
Watkins Mill Lake	Clay	D	100 ac	1971	Recreation	High
Little Prairie Lake	Phelps	C	100 ac	1965	Recreation	High
Fox Valley Lake	Clark	B	96 ac	1983	Recreation	High
Blind Pony Lake	Saline	F	95 ac	1968	Recreation	Low
Lake Arrowhead	Clinton	D	87 ac	1975	Recreation	High
Lake Wauwanoka Nr. Dam	Jefferson	A	86 ac	1942	Recreation	High
Waukomis Lake	Platte	C	82 ac	1968	Recreation	High
Finger Lakes	Boone	B	79 ac	—	Recreation	High
Teal Lake	Audrain	F	78 ac	1969	Recreation	High
Lake Tapawingo	Jackson	D	78 ac	1926	Recreation	High
Manito Lake by Dam	Moniteau	D	77 ac	1984	Recreation	High
North Bethany City Reservoir	Harrison	B	76 ac	1960	Water Supply	High
Hamilton Lake	Caldwell	D	76 ac	1954	Water Supply	High
Unionville Lake	Putnam	F	75 ac	1941	Recreation	Low
Nodaway Lake	Nodaway	D	73 ac	1966	Recreation	High
Hazel Hill Lake by Dam	Johnson	D	71 ac	1989	Recreation	Significant
L. Ste. Louise Lake	St. Charles	D	70 ac	1967	Recreation	High
L. Ste. Louise Lake	St. Charles	D	70 ac	1967	Recreation	High
Lake Serene	Franklin	D	65 ac	1957	Recreation	High
Marceline Lake	Linn	F	65 ac	1928	Water Supply	High
Lake of the Oaks	Clark	C	65 ac	1962	Recreation	High
Happy Holler Lake	Andrew	C	62 ac	1995	Recreation	High
Lake Marseilles-Terre du Lac Lakes	St. Francois	A	56 ac	1971	Recreation	High
Port Hudson Lake	Franklin	C	55 ac	1992	Fish and Wildlife Pond	High
Rocky Fork Lake	Boone	F	55 ac	1965	Other	Low
Lake Shayne-Terre du Lac Lakes	Washington	A	51 ac	1979	Recreation	High
Drexel City Reservoir South Nr. Dam	Bates	F	50 ac	1968	Recreation	Low
Buck 15 Lake	Camden	D	50 ac	2000	Recreation	Significant
Monroe City Lake B Nr. Dam	Monroe	C	50 ac	1937	Recreation	High
Fourche Creek Lake	Ripley	A	49 ac	1975	Recreation	High
Lake 35	St. Charles	D	49 ac	1963	Recreation	High
Lincoln Lake	Lincoln	B	48 ac	1965	Recreation	High
Deer Ridge Comm. Lake	Lewis	D	48 ac	1960	Recreation	High
Belcher Branch Lake	Buchanan	D	46 ac	1992	Fish and Wildlife Pond	High
Bowling Green Lake	Pike	C	45 ac	1954	Water Supply	High
Buffalo Bill Lake 0.4 Mi From Dam	DeKalb	D	45 ac	1990	Flood Risk Reduction	High
Buffalo Bill Lake Nr. Access	DeKalb	D	45 ac	1990	Flood Risk Reduction	High
Ben Branch Lake by Dam	Osage	D	44 ac	1984	Recreation	High
Catclaw Lake	Jackson	F	43 ac	1966	Recreation	Low
Timberline Lakes	St. Francois	A	42 ac	1963	Recreation	High
Cole Lake	Jefferson	B	42 ac	1948	Recreation	High
Lake Lucern	Warren	C	42 ac	1971	Recreation	High
Memphis Lake No.1	Scotland	F	41 ac	1931	Recreation	High
Gopher Lake	Jackson	F	40 ac	1966	Recreation	Low
Lost Valley Lake	Gasconade	C	39 ac	1974	Recreation	High
Innsbrook Lake Nr. Dam	Warren	B	39 ac	1975	Recreation	High
Vandalia Community Lake	Audrain	F	38 ac	1956	Recreation	High
Sterling Price Lake	Chariton	F	35 ac	1958	Recreation	Low
Phillips Lake	Boone	C	33 ac	1965	Recreation	High
Jo Shelby Lake	Linn	C	31 ac	1958	Recreation	Low
Nell Lake	Jackson	F	30 ac	1955	Recreation	Low
Lake Marie	Mercer	B	30 ac	1981	Recreation	High
Shelbyville Lake	Shelby	F	30 ac	1956	Recreation	High
Lake 37	St. Charles	B	30 ac	1970	Recreation	High
Jamesport Community Lake	Daviess	F	30 ac	1956	Recreation	Low
Ashland Lake	Boone	F	29 ac	1937	Other	Low
Loto Lake	Camden	C	29 ac	1975	Recreation	High
Jackrabbit Lake	Jackson	F	28 ac	1955	Recreation	Low
North Lake	Cass	F	28 ac	1955	Recreation	Low
Tri City Lake	Boone	D	28 ac	1957	Recreation	Low
Limpp Lake	Gentry	F	28 ac	1960	Recreation	High
Rock Lake Village Lake	Johnson	B	27 ac	2006	—	High
Rinquelin Trail Comm. Lake	Maries	C	27 ac	1972	Recreation	Significant
Rothwell Lake	Randolph	C	26 ac	1902	Recreation	High
Fon-du-Lac Reservoir	Jefferson	F	26 ac	1954	Recreation	High
Fawn Lake	Franklin	C	25 ac	1969	Recreation	Significant
Coot Lake	Jackson	F	23 ac	1958	Other	High
Crowder S.P. Lake	Grundy	F	22 ac	1941	Recreation	Low
Jamesport City Lake	Daviess	D	22 ac	1955	Water Supply	Low
Cameron Lake Deep Site	DeKalb	F	21 ac	1925	Water Supply	High
Old Reservoir	Randolph	C	21 ac	1870	Recreation	High
Harrisonville City Lake	Cass	F	21 ac	1934	Water Supply	High
Shepard Mountain Lake Intake	Iron	D	21 ac	1955	Recreation	High
Cottontail Lake	Jackson	F	21 ac	1966	Recreation	Low
Cedar Lake	Boone	F	21 ac	1975	Recreation	High
Ripley County Lake	Ripley	B	20 ac	1958	Recreation	Significant
Whiteside Lake	Lincoln	C	20 ac	1980	Recreation	High
Lake Wooldridge	Saline	F	20 ac	1963	Recreation	High
Lake Konstanz	Warren	B	19 ac	1999	—	High
Houston Lake	Platte	F	19 ac	1930	Recreation	High
Sugar Hollow Lake	Warren	D	17 ac	1968	Recreation	High
Lake Luna	Cass	F	17 ac	1920	Recreation	High
Sugar Hollow Lake	Warren	D	17 ac	1968	Recreation	High
Knob Noster S.P. Lake 2	Johnson	C	16 ac	1936	Recreation	Low
Lake 36	St. Charles	D	16 ac	1962	Recreation	High
Perry City Lake	Ralls	F	16 ac	1964	Water Supply	High
Milan Lake North	Sullivan	B	15 ac	1911	Recreation	Low
Seetal Lake	Gasconade	B	14 ac	1971	Recreation	High
Whippoorwill Lake	Warren	B	13 ac	1964	Recreation	High
Red Fox Lake	Warren	C	13 ac	1964	Recreation	High
Mckee Pond	Boone	C	13 ac	1979	Recreation	High
Port Perry Lake North Arm	Perry	B	12 ac	1972	Recreation	High
Stephens Lake	Boone	D	11 ac	1939	Recreation	High
Cedar Hill Lake 1	Jefferson	D	11 ac	1949	Recreation	High
Cattails 1 Lake	Jefferson	B	11 ac	1960	Recreation	Low
Castlenovo Lake	Warren	B	10 ac	1976	Recreation	High
Izaak Walton Lake	Vernon	F	10 ac	1926	Recreation	High
Mccormack Lake	Oregon	A	10 ac	1937	Recreation	Significant
Robin Hood Lakes	Warren	D	9 ac	1970	Recreation	Low
Robin Hood Lake	Warren	D	9 ac	1970	Recreation	Low
Lake of the Woods	Boone	B	9 ac	1960	Recreation	High
Bee Tree Lake	St. Louis	F	9 ac	1972	Recreation	High
Lake Buteo	Johnson	B	8 ac	1927	Recreation	Low
Railraod Lake	Moniteau	F	8 ac	1900	Recreation	Low
Loto Lake	Morgan	D	7 ac	1972	Recreation	Low
Marion Reservoir	Franklin	B	7 ac	1965	Recreation	Low
Lake of the Woods-Kc	Jackson	F	6 ac	1907	Other	Low
Lick 10 Lake	Camden	C	6 ac	1991	Water Supply	High
Lewis Lake	Stoddard	F	6 ac	1995	Fish and Wildlife Pond	Low
Lake of the Woods	Jackson	F	6 ac	1907	Other	Low
Loto Lake	Camden	B	5 ac	1972	Recreation	Low
Foxboro Lake	Franklin	D	4 ac	1974	Fish and Wildlife Pond	Significant
Cattails 2 Lake	Jefferson	A	4 ac	1971	Other	High
Lake Eleanor	Warren	D	3 ac	1966	Recreation	Low
Lake Eleanor	Warren	D	3 ac	1966	Recreation	Low
Council Bluff Lake	Iron	A	—	1981	Recreation	High

Frequently Asked Questions

How many reservoirs are in Wisconsin?

205 of 388 graded Wisconsin lakes (53%) are man-made reservoirs in the USACE National Inventory of Dams. 162 are rated High or Significant hazard, meaning failure would put downstream lives or property at substantial risk. The oldest matched dam dates to 1870.

What's the largest reservoir in Wisconsin?

The largest matched reservoir in Wisconsin is H.S. Truman Res. Nr. Dam Lake in Benton County at 55,600 acres of normal surface area, impounded by the Harry S. Truman Dam (completed 1979).

What's the difference between a reservoir and a natural lake?

A reservoir is a body of water impounded by a man-made dam — typically built for flood control, hydroelectric power, water supply, irrigation, or recreation. A natural lake formed without human intervention, usually from glacial scouring, volcanic activity, or river meandering. Reservoirs typically have shoreline that fluctuates with seasonal water level management, while natural lakes have more stable shorelines. The USACE National Inventory of Dams classifies every regulated dam in the United States, which is how we identify which LakeGrade lakes are actually reservoirs.

What does the hazard class mean?

USACE assigns each dam a hazard potential classification based on what would happen downstream if the dam failed — NOT how likely the dam is to fail. "Low" hazard means dam failure would cause no probable loss of life and only low economic loss. "Significant" means probable loss of life is unlikely but appreciable economic damage would occur. "High" means probable loss of life and significant economic damage. The classification is about consequence, not condition. Many High-hazard dams are perfectly safe; they're rated High because populated areas have grown downstream over time.

Where does this reservoir data come from?

Every reservoir record on this page is matched to the USACE National Inventory of Dams (NID), the federal database of all dams ≥25 ft tall or impounding ≥50 acre-feet, plus any dam that poses a Significant or High hazard regardless of size. The NID is published by the U.S. Army Corps of Engineers and updated annually. Surface area, storage capacity, dam height, and hazard classification come directly from NID records.

Data source

Reservoir data from the USACE National Inventory of Dams (NID), the federal database of all regulated dams. Dam attributes (height, year completed, storage capacity, hazard class) are matched to LakeGrade lakes by proximity and dam-name similarity. Some lakes may be reservoirs that aren't matched if the dam record uses a name substantially different from our lake name.