
Hypereutrophic Lakes in Minnesota
124 hypereutrophic lakes in Minnesota. Very high nutrients, dense algae, poor clarity.
Hypereutrophic lakes (TSI above 70) are at the upper end of the productivity scale: visible algal blooms most weeks of summer, clarity often under 3 feet, and meaningful risk of harmful-algal-bloom toxin events. 124 hypereutrophic lakes are on the Minnesota books. Almost none of them are deep — 2% break 50 feet. Shallow basin plus heavy nutrient input is the consistent recipe.
Hypereutrophic lakes overwhelmingly grade D or F — the trophic class and the grade are measuring closely-related dimensions of the same underlying nutrient regime.
| # | Lake | County | Grade | Clarity | Depth | TSI |
|---|---|---|---|---|---|---|
| 1 | Union Lake | Rice | D | 3 ft | 10 ft | 72 |
| 2 | Rice Lake | Scott | D | 1.7 ft | - | 77 |
| 3 | Scotch Lake | Le Sueur | D | 2.6 ft | 11 ft | 71 |
| 4 | Kansas Lake | Watonwan | D | 1.5 ft | 7 ft | 71 |
| 5 | Yankton Lake | Lyon | D | 0.8 ft | 8 ft | 70 |
| 6 | Gonz Lake | Wright | D | - | - | 74 |
| 7 | O'Leary Lake | Dakota | F | 2.6 ft | 33.5 ft | 71 |
| 8 | Mud Lake | Hennepin | F | 0.9 ft | - | 78 |
| 9 | Mud Lake | Washington | F | 1.2 ft | - | 72 |
| 10 | Mud Lake | Martin | F | 1.6 ft | 19 ft | 71 |
| 11 | Snelling Lake | Hennepin | F | 1.8 ft | 9.5 ft | 71 |
| 12 | Long Lake | Dakota | F | 1.6 ft | - | 72 |
| 13 | Unnamed Lake | Meeker | F | 0.7 ft | 15 ft | 80 |
| 14 | Unnamed Lake | Hennepin | F | - | - | 78 |
| 15 | Jonathan Lake | Carver | F | 1.6 ft | - | 74 |
| 16 | Peltier Lake | Anoka | F | 2.5 ft | 18 ft | 74 |
| 17 | Tetonka Lake | Le Sueur | F | 3 ft | 35 ft | 72 |
| 18 | Clear Lake | Meeker | F | 3 ft | 18 ft | 70 |
| 19 | Clear Lake | Brown | F | 0.8 ft | 8 ft | 78 |
| 20 | Clear Lake | Waseca | F | 2.5 ft | 34 ft | 70 |
| 21 | Clear Lake | Le Sueur | F | 1.2 ft | 18 ft | 78 |
| 22 | Clear Lake | Martin | F | 1 ft | 7 ft | 71 |
| 23 | Eagle Lake | Carver | F | 2 ft | 14 ft | 73 |
| 24 | Fish Lake | Becker | F | 1 ft | - | 76 |
| 25 | Wheeler North Lake | Kandiyohi | F | 1 ft | - | 80 |
| 26 | Roberds Lake | Rice | F | 2.5 ft | 43 ft | 75 |
| 27 | Charlotte Lake | Stevens | F | 0.9 ft | 20 ft | 79 |
| 28 | Emily Lake | Chisago | F | 1.6 ft | - | 71 |
| 29 | Rice Lake | Hennepin | F | 2.3 ft | 11.5 ft | 77 |
| 30 | Pokegama Lake | Pine | F | 2 ft | 25 ft | 71 |
| 31 | George Lake | Martin | F | 2 ft | 11 ft | 71 |
| 32 | Big Woods Lake | Carver | F | 1.5 ft | - | 76 |
| 33 | Goose Lake | Ramsey | F | 0.7 ft | 6 ft | 80 |
| 34 | Goose Lake | Carver | F | 1.2 ft | 10 ft | 77 |
| 35 | Goose Lake | Goodhue | F | 0.4 ft | 5.7 ft | 80 |
| 36 | Goose Lake | Hennepin | F | 0.8 ft | 8 ft | 77 |
| 37 | Goose Lake | Washington | F | 1.5 ft | - | 71 |
| 38 | Typo Lake | Anoka | F | 1 ft | 6 ft | 77 |
| 39 | Powderhorn Lake | Hennepin | F | 1.5 ft | 24 ft | 72 |
| 40 | Fountain Lake | Wright | F | 1 ft | 10 ft | 78 |
| 41 | Crystal Lake | Blue Earth | F | 1.5 ft | 8 ft | 73 |
| 42 | Benton Lake | Carver | F | 1 ft | - | 77 |
| 43 | Foster Lake | Wright | F | 1.6 ft | 10 ft | 75 |
| 44 | Knife Lake | Kanabec | F | 2 ft | 15 ft | 73 |
| 45 | Diamond Lake | Hennepin | F | 1.7 ft | 8 ft | 73 |
| 46 | Ardmore Lake | Hennepin | F | 1.3 ft | 20 ft | 79 |
| 47 | Francis Lake | Isanti | F | 2 ft | 7 ft | 71 |
| 48 | Rebecca Lake | Dakota | F | 2.6 ft | 15 ft | 71 |
| 49 | Schultz Lake | Kandiyohi | F | 1.3 ft | - | 76 |
| 50 | Alice Lake | Otter Tail | F | 0.8 ft | - | 86 |
| 51 | Arvilla Lake | Meeker | F | 1 ft | 9 ft | 75 |
| 52 | Vadnais Lake | Ramsey | F | 1 ft | 9 ft | 74 |
| 53 | Victoria Lake | Hennepin | F | 1.2 ft | - | 70 |
| 54 | Rose Lake | Washington | F | 1.8 ft | 11.3 ft | 72 |
| 55 | Circle Lake | Rice | F | 1.5 ft | 14 ft | 79 |
| 56 | Little Rock Lake | Benton | F | 1.8 ft | 17 ft | 74 |
| 57 | Hanska Lake | Brown | F | 1 ft | 16 ft | 78 |
| 58 | Fox Lake | Martin | F | 1 ft | 20 ft | 76 |
| 59 | Fox Lake | Murray | F | 0.6 ft | 8.5 ft | 78 |
| 60 | Cleary Lake | Scott | F | 2.3 ft | 9 ft | 72 |
| 61 | Hazeltine Lake | Carver | F | 1 ft | - | 77 |
| 62 | Loon Lake | Jackson | F | 0.9 ft | 8 ft | 80 |
| 63 | Sylvan Lake | Hennepin | F | 1.2 ft | - | 78 |
| 64 | Cameron Lake | Polk | F | 1 ft | 9 ft | 76 |
| 65 | Miller Lake | Carver | F | 1.6 ft | 14 ft | 76 |
| 66 | Mcknight Lake | Carver | F | 2.2 ft | - | 71 |
| 67 | Parley Lake | Carver | F | 1.8 ft | 18 ft | 70 |
| 68 | Spring Lake | Hennepin | F | 3.4 ft | - | 76 |
| 69 | French Lake | Rice | F | 1.7 ft | 56 ft | 71 |
| 70 | Amber Lake | Martin | F | 2 ft | 19 ft | 70 |
| 71 | Swede Lake | Carver | F | 2 ft | 12 ft | 72 |
| 72 | Augusta Lake | Dakota | F | 0.7 ft | - | 79 |
| 73 | Malmedal Lake | Pope | F | 1.6 ft | 10 ft | 74 |
| 74 | Simon Lake | Pope | F | 1.3 ft | - | 72 |
| 75 | Dean Lake | Wright | F | 4.3 ft | 20 ft | 70 |
| 76 | Lower Orono Lake | Sherburne | F | 2.5 ft | 18 ft | 71 |
| 77 | Unn Pond | Dakota | F | 2 ft | - | 70 |
| 78 | Uhlenkolts Lake | Stearns | F | 0.7 ft | 18 ft | 82 |
| 79 | Cottonwood Lake | Lyon | F | 1.8 ft | 7 ft | 72 |
| 80 | Wells Lake | Rice | F | 2 ft | 4 ft | 72 |
| 81 | Pearl Lake | Jackson | F | 1 ft | 6 ft | 77 |
| 82 | Mccarthy Lake | Dakota | F | 1 ft | 19 ft | 79 |
| 83 | Stay Lake | Lincoln | F | 1 ft | 6 ft | 74 |
| 84 | East Toqua Lake | Big Stone | F | 1.6 ft | 9 ft | 78 |
| 85 | Indian Lake | Nobles | F | 2.5 ft | 6 ft | 72 |
| 86 | Maria Lake | Carver | F | 0.8 ft | 6 ft | 86 |
| 87 | Shakopee Lake | Chippewa | F | 1.5 ft | - | 79 |
| 88 | Millstone Lake | Wright | F | 0.8 ft | 8.5 ft | 77 |
| 89 | Little Mary Lake | Wright | F | 1.5 ft | - | 74 |
| 90 | Upper Sakatah Lake | Le Sueur | F | 3 ft | 12 ft | 74 |
| 91 | Albion Lake | Wright | F | 1 ft | - | 75 |
| 92 | Wilhelm Lake | Wright | F | 2 ft | - | 71 |
| 93 | Split Rock Reservoir | Pipestone | F | 1.3 ft | 16 ft | 75 |
| 94 | Little Waverly Lake | Wright | F | 1.5 ft | 12 ft | 80 |
| 95 | Northwood Lake | Hennepin | F | 1.5 ft | - | 75 |
| 96 | Swartout Lake | Wright | F | 4.6 ft | - | 73 |
| 97 | Henshaw Lake | Wright | F | 1 ft | 8 ft | 74 |
| 98 | Byllesby Lake | Dakota | F | 3 ft | 50 ft | 70 |
| 99 | Ocheda Lake | Nobles | F | 1.6 ft | 5 ft | 76 |
| 100 | Cowley Lake | Hennepin | F | 0.8 ft | - | 89 |
All hypereutrophic lakes →Wisconsin version →Illinois version →Michigan version →Iowa version →Ohio version →Pennsylvania version →New York version →Missouri version →Indiana version →North Dakota version →South Dakota version →Florida version →Colorado version →North Carolina version →Vermont version →Texas version →Oregon version →Arkansas version →Oklahoma version →Kansas version →Nebraska version →Nevada version →Arizona version →Idaho version →Montana version →New Mexico version →Tennessee version →Alabama version →Virginia version →Kentucky version →Utah version →Washington version →Wyoming version →Georgia version →Massachusetts version →Ontario version →Québec version →Nova Scotia version →British Columbia version →Newfoundland and Labrador version →All Minnesota lakes →
Source: EPA National Aquatic Resource Surveys, 2026.