Hypereutrophic Lakes in Ohio
13 hypereutrophic lakes in Ohio. 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. 13 hypereutrophic lakes are on the Ohio books. Almost none of them are deep — 0% break 50 feet. Shallow basin plus heavy nutrient input is the consistent recipe.
Hypereutrophic lakes carry the highest phosphorus and chlorophyll-a readings on record; the trophic class and the readings are measuring closely related dimensions of the same underlying nutrient regime.
| # | Lake | County | Clarity | Depth | TSI |
|---|---|---|---|---|---|
| 1 | Maumee R Upst Independence Dam Lake | Defiance | - | - | 75 |
| 2 | Amann Reservoir | Morrow | - | - | 83 |
| 3 | Buck Creek Lake | Clark | 2.5 ft | - | 63 |
| 4 | Auglaize R Lake | Paulding | - | - | 74 |
| 5 | Spring Valley Lake Lake | Columbiana | - | - | 82 |
| 6 | Somerset Reservoir | Perry | - | - | 65 |
| 7 | Grand Lake St Marys @ Intake | Mercer | - | - | 84 |
| 8 | St Joseph Lake | Perry | - | - | 67 |
| 9 | Alum Creek Lake | Delaware | - | - | 69 |
| 10 | Amicks Reservoir | Morrow | - | - | 65 |
| 11 | O'Shaughnessy Reservoir Lake | Delaware | - | - | 73 |
| 12 | Bresler Reservoir | Allen | - | - | 67 |
| 13 | Hoover Reservoir | Delaware | - | - | 75 |
All hypereutrophic lakes →Minnesota version →Wisconsin version →Illinois version →Michigan version →Iowa 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 Ohio lakes →
Source: EPA National Aquatic Resource Surveys, 2026.