Reservoirs in Wisconsin
62 of 754 graded Wisconsin lakes (8%) are man-made reservoirs in the USACE National Inventory of Dams. 25 carry a High or Significant hazard rating.
Why these Wisconsin reservoirs were built
All 62 Wisconsin reservoirs (by surface area)
| Reservoir | County | Grade | Surface area | Year built | Purpose | Hazard |
|---|---|---|---|---|---|---|
| Hubbard Lake | Alcona | A | 8,800 ac | 1890 | Hydroelectric | Low |
| Lake Independence | Marquette | C | 2,071 ac | 1913 | Recreation | Low |
| Gull Lake | Kalamazoo | B | 2,050 ac | 1920 | Recreation | Low |
| Lake Bellaire | Antrim | C | 1,520 ac | 1906 | Recreation | High |
| Tippy Pond by Dam | Manistee | A | 1,330 ac | 1918 | Hydroelectric | High |
| Van Etten Lake | Iosco | D | 1,320 ac | 1947 | Recreation | Low |
| Lake Lancer | Gladwin | A | 977 ac | 1976 | Recreation | High |
| Lake James | Roscommon | C | 900 ac | 1962 | Recreation | High |
| Lake Templene | St. Joseph | D | 870 ac | 1972 | Recreation | Significant |
| Cass Lake South Central Basin; W. Bloomfield Township Section 3 | Oakland | A | 850 ac | 1968 | Flood Risk Reduction | Low |
| Corey Lake Southeastern Basin; Fabius Township | St. Joseph | A | 567 ac | 1974 | Recreation | Low |
| Union Lake Southwest Basin; Sherwood Township Section 11 | Branch | D | 518 ac | 1923 | Hydroelectric | Significant |
| Lake Orion | Oakland | B | 470 ac | 1829 | Other | Significant |
| Lake Orion East Central Basin; Orion Township Section 11 | Oakland | A | 470 ac | 1829 | Other | Significant |
| Lakeville Lake | Oakland | C | 460 ac | 1913 | Other | Low |
| Lakeville Lake Central Basin | Oakland | B | 460 ac | 1913 | Other | Low |
| Lake Lansing Northwest Basin; Meridian Township | Ingham | A | 453 ac | 1975 | Recreation | Low |
| Rogers Dam Pond; Central Basin; Mecosta Township | Mecosta | B | 449 ac | 1906 | Hydroelectric | High |
| Whitmore Lake | Livingston | C | 441 ac | 1969 | Recreation | Low |
| Horsehead Lake | Mecosta | B | 430 ac | 1961 | Other | Low |
| Lobdell Lake West Basin; Argentine Township | Genesee | C | 416 ac | 1929 | Recreation | Significant |
| Lake Ovid | Clinton | D | 413 ac | 1974 | Flood Risk Reduction | Significant |
| Lake Ovid North Basin; Ovid Township | Clinton | C | 413 ac | 1974 | Flood Risk Reduction | Significant |
| Wormer Lake | Oakland | B | 370 ac | 1915 | Recreation | Significant |
| Mohawk Lake | Oakland | B | 370 ac | 1915 | Recreation | Significant |
| Canadian Lake Southeast Basin; Morton Township | Mecosta | F | 361 ac | 1965 | Recreation | Significant |
| Avery Lake | Montmorency | A | 322 ac | 1970 | Recreation | Low |
| Lake Lapeer | Lapeer | D | 297 ac | 1969 | Recreation | Significant |
| Lake Lapeer Central Basin; Elba Township | Lapeer | F | 297 ac | 1969 | Recreation | Significant |
| Lake Diane South Basin; Amboy Township | Hillsdale | D | 290 ac | 1966 | Recreation | Significant |
| Cedar Island Lake | Oakland | B | 290 ac | 1964 | Recreation | High |
| Oxbow Lake Southeast Basin; White Lake Township Section 26 | Oakland | A | 290 ac | 1964 | Recreation | High |
| Oxbow Lake | Oakland | A | 290 ac | 1964 | Recreation | High |
| Sugarloaf Lake | Washtenaw | C | 280 ac | 1956 | Recreation | Significant |
| Sugarloaf Lake; Lyndon Twp | Washtenaw | B | 280 ac | 1956 | Recreation | Significant |
| Lake Lancelot | Gladwin | C | 250 ac | 1976 | Recreation | Low |
| Lancelot Lake Southwest Basin | Gladwin | B | 250 ac | 1976 | Recreation | Low |
| Louis Lake East Central Basin; Waucedah Township | Dickinson | B | 230 ac | — | Other | Low |
| Louise Lake | Dickinson | B | 230 ac | — | Other | Low |
| Mary Lake Central Basin Southeast; Waucedah Township | Dickinson | B | 230 ac | — | Other | Low |
| Mary Lake | Dickinson | B | 230 ac | — | Other | Low |
| Posey Lake | Lenawee | D | 150 ac | 1955 | Recreation | Low |
| Posey Lake Central Basin; Hudson Township | Lenawee | C | 150 ac | 1955 | Recreation | Low |
| Wakeley Lake; Central Basin; Grayling Township | Crawford | B | 149 ac | 1991 | Fish and Wildlife Pond | Low |
| Wakeley Lake | Crawford | D | 149 ac | 1991 | Fish and Wildlife Pond | Low |
| Oneal Lake | Emmet | A | 138 ac | 1954 | Recreation | Low |
| Little Lake Twenty | Gladwin | C | 128 ac | 1974 | Recreation | Low |
| Lake Twenty East Basin | Gladwin | C | 128 ac | 1974 | Recreation | Low |
| Crystal Lake | Hillsdale | B | 125 ac | 1976 | Recreation | Low |
| Perch Lake | Hillsdale | F | 125 ac | 1976 | Recreation | Low |
| Perch Lake | Hillsdale | F | 125 ac | 1976 | Recreation | Low |
| Crystal Lake | Hillsdale | C | 125 ac | 1976 | Recreation | Low |
| Barnes Lake | Lapeer | A | 110 ac | 1935 | Recreation | Low |
| Barnes Lake | Lapeer | B | 110 ac | 1935 | Recreation | Low |
| Shavehead Lake | Cass | C | 93 ac | 1960 | Recreation | Low |
| Tull Lake Central Basin; White Lake Township | Oakland | D | 81 ac | — | Recreation | Low |
| Thread Lake Central Basin | Genesee | C | 80 ac | 1973 | Recreation | Significant |
| Thread Lake | Genesee | F | 80 ac | 1973 | Recreation | Significant |
| Hemmingway Lake | Lapeer | C | 65 ac | 1912 | Recreation | Low |
| Hemingway Lake | Lapeer | C | 65 ac | 1912 | Recreation | Low |
| Lake Victoria | Clinton | C | 52 ac | 1961 | Recreation | Low |
| Victoria Lake North of Central Island; Victor Township | Clinton | C | 52 ac | 1961 | Recreation | Low |
Frequently Asked Questions
How many reservoirs are in Wisconsin?
62 of 754 graded Wisconsin lakes (8%) are man-made reservoirs in the USACE National Inventory of Dams. 25 are rated High or Significant hazard, meaning failure would put downstream lives or property at substantial risk. The oldest matched dam dates to 1829.
What's the largest reservoir in Wisconsin?
The largest matched reservoir in Wisconsin is Hubbard Lake in Alcona County at 8,800 acres of normal surface area, impounded by the Hubbard Lake Dam (completed 1890).
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.