Hypereutrophic Lakes Across 12 States
Very high nutrients, dense algae, poor clarity. 394 lakes (7% of all graded lakes).
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. 394 hypereutrophic lakes are on the the 12 states LakeQuality covers books. Almost none of them are deep — 3% 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 | State | Grade | Clarity | Depth |
|---|---|---|---|---|---|
| Kramer Lake | Washington | MN | D | 1 ft | - |
| Ann Lake | Pope | MN | D | 7.2 ft | 14 ft |
| Dry Lake | Ramsey | ND | D | 2.8 ft | 24.1 ft |
| Sweetwater Lake | Ramsey | ND | D | 2.9 ft | - |
| Clear Lake | Martin | MN | D | 1 ft | 7 ft |
| Star Lake | Meeker | MN | D | 1 ft | 15 ft |
| Mud Lake | Otter Tail | MN | D | 1.3 ft | - |
| Unnamed Lake | Wright | MN | D | 1.3 ft | 38 ft |
| Ann Lake | Wright | MN | D | 4 ft | 18.5 ft |
| Spring Lake | Hennepin | MN | D | 3.4 ft | - |
| Brownie Lake | Hennepin | MN | D | 5 ft | 47 ft |
| Dean Lake | Wright | MN | D | 4.3 ft | 20 ft |
| Scotch Lake | Le Sueur | MN | D | 4.1 ft | 11 ft |
| Swartout Lake | Wright | MN | D | 4.6 ft | - |
| Porter Lake | Blue Earth | MN | D | 1.3 ft | - |
| Winsted Lake | McLeod | MN | D | 3.3 ft | 12 ft |
| Gorman Lake | Le Sueur | MN | D | 3.7 ft | 14 ft |
| Cannon Lake | Rice | MN | D | 4.1 ft | 15 ft |
| Lazy Lake | Columbia | WI | D | 4 ft | 8 ft |
| Bluff Lake | Lake | IL | D | 4 ft | - |
| Fox Lake Central Basin; Dalton Township | Muskegon | MI | D | 1 ft | - |
| Valley Lake | Jackson | MO | D | - | - |
| Mud Lake | Washington | MN | F | 1.2 ft | - |
| Rice Lake | Scott | MN | F | 1.7 ft | - |
| Victoria Lake | Hennepin | MN | F | 1.2 ft | - |
| Harrison County Lake | Harrison | MO | F | 1.5 ft | - |
| Pomme de Terre Lake | Hickory | MO | F | 1.2 ft | - |
| Mckay Park Lake | Cole | MO | F | 1 ft | - |
| Edwin A Pape Lake | Lafayette | MO | F | 1.8 ft | - |
| Harrisonville Lake | Cass | MO | F | 1.1 ft | - |
| Long Lake | Stearns | MN | F | 2.5 ft | 35 ft |
| Long Lake | Cottonwood | MN | F | 1 ft | - |
| Long Lake | Dakota | MN | F | 1.6 ft | - |
| Jonathan Lake | Carver | MN | F | 1.5 ft | - |
| Peltier Lake | Anoka | MN | F | 2.5 ft | 18 ft |
| Clear Lake | Brown | MN | F | 0.8 ft | 8 ft |
| Clear Lake | Waseca | MN | F | 2.5 ft | 34 ft |
| Clear Lake | Stevens | MN | F | 0.7 ft | - |
| Clear Lake | Le Sueur | MN | F | 1.2 ft | 18 ft |
| Eagle Lake | Carver | MN | F | 2 ft | 14 ft |
| Eagle Lake | Blue Earth | MN | F | 1 ft | 9 ft |
| Fish Lake | Becker | MN | F | 1 ft | - |
| Allie Lake | Renville | MN | F | 3 ft | 12 ft |
| Roberds Lake | Rice | MN | F | 2.5 ft | 43 ft |
| Charlotte Lake | Stevens | MN | F | 0.9 ft | 20 ft |
| Mud Lake | Hennepin | MN | F | 0.9 ft | - |
| Mud Lake | Hennepin | MN | F | 3 ft | - |
| Mud Lake | Martin | MN | F | 1.6 ft | 19 ft |
| Pike Lake | Scott | MN | F | 2.3 ft | 9 ft |
| Unnamed Lake | Meeker | MN | F | 0.7 ft | 15 ft |
| Unnamed Lake | Benton | MN | F | 1.5 ft | - |
| Unnamed Lake | Becker | MN | F | 1.2 ft | - |
| Unnamed Lake | Swift | MN | F | 0.7 ft | - |
| Unnamed Lake | Watonwan | MN | F | 1 ft | - |
| Unnamed Lake | Otter Tail | MN | F | 1.3 ft | - |
| Unnamed Lake | Big Stone | MN | F | 2 ft | 15 ft |
| Unnamed Lake | Stevens | MN | F | 1.1 ft | - |
| Unnamed Lake | Grant | MN | F | 0.7 ft | - |
| Unnamed Lake | Brown | MN | F | 0.3 ft | - |
| Unnamed Lake | Hennepin | MN | F | - | - |
| Tetonka Lake | Le Sueur | MN | F | 3 ft | 35 ft |
| Wakanda Lake | Kandiyohi | MN | F | 0.5 ft | - |
| Saint Johns Lake | Kandiyohi | MN | F | 0.5 ft | - |
| Wheeler North Lake | Kandiyohi | MN | F | 1 ft | - |
| Union Lake | Rice | MN | F | 3 ft | 10 ft |
| Island Lake | Lyon | MN | F | 2 ft | 8 ft |
| Rice Lake | Hennepin | MN | F | 2.3 ft | 11.5 ft |
| Pokegama Lake | Pine | MN | F | 2 ft | 25 ft |
| George Lake | Martin | MN | F | 2 ft | 11 ft |
| Ox Yoke Lake | Hennepin | MN | F | 2.6 ft | - |
| Big Woods Lake | Carver | MN | F | 1.4 ft | - |
| Powderhorn Lake | Hennepin | MN | F | 1.5 ft | 24 ft |
| Fountain Lake | Wright | MN | F | 1 ft | 10 ft |
| Goose Lake | Ramsey | MN | F | 0.7 ft | 6 ft |
| Goose Lake | Carver | MN | F | 1 ft | 10 ft |
| Goose Lake | Goodhue | MN | F | 0.4 ft | 5.7 ft |
| Goose Lake | Hennepin | MN | F | 0.8 ft | 8 ft |
| Goose Lake | Washington | MN | F | 1.5 ft | - |
| Benton Lake | Carver | MN | F | 1 ft | - |
| Foster Lake | Wright | MN | F | 1.6 ft | 10 ft |
| Silver Lake | Mille Lacs | MN | F | 1 ft | - |
| Typo Lake | Anoka | MN | F | 1 ft | 6 ft |
| Crystal Lake | Blue Earth | MN | F | 1.5 ft | 8 ft |
| Crystal Lake | Rice | MN | F | - | - |
| Knife Lake | Kanabec | MN | F | 2 ft | 15 ft |
| Diamond Lake | Hennepin | MN | F | 1.7 ft | 8 ft |
| Ardmore Lake | Hennepin | MN | F | 1.3 ft | 20 ft |
| Rebecca Lake | Dakota | MN | F | 2.6 ft | 15 ft |
| Uhl Lake | Wright | MN | F | 1 ft | - |
| Cornelia Lake | Hennepin | MN | F | 0.8 ft | 6.5 ft |
| Wood Lake | Yellow Medicine | MN | F | 3 ft | 9 ft |
| Arvilla Lake | Meeker | MN | F | 1 ft | 9 ft |
| Schultz Lake | Kandiyohi | MN | F | 1.3 ft | - |
| Alice Lake | Otter Tail | MN | F | 0.8 ft | - |
| Rose Lake | Washington | MN | F | 1.8 ft | 11.3 ft |
| Vadnais Lake | Ramsey | MN | F | 1 ft | 9 ft |
| Langdon Lake | Hennepin | MN | F | 1.5 ft | 38 ft |
| Little Rock Lake | Benton | MN | F | 1.8 ft | 17 ft |
| Circle Lake | Rice | MN | F | 1.5 ft | 14 ft |
| Hanska Lake | Brown | MN | F | 1 ft | 16 ft |
Showing 100 of 394 hypereutrophic lakes.
Frequently Asked Questions
What is an hypereutrophic lake?
Very high nutrients, dense algae, poor clarity. There are 394 hypereutrophic lakes across the 12 states LakeQuality covers, representing 7% of all graded lakes.
Can you swim in hypereutrophic lakes?
Hypereutrophic lakes are generally not safe for swimming due to dense algae, potential toxins, and very poor visibility.
Source: EPA National Aquatic Resource Surveys, 2026.