Hypereutrophic Lakes in Colorado
8 hypereutrophic lakes in Colorado. 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. 8 hypereutrophic lakes are on the {{stateName}} books. Almost none of them are deep — 0% 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 | Prospect Lake | Weld | F | - | - | 76 |
| 2 | North Sterling Reservoir | Logan | F | 1.1 ft | - | 75 |
| 3 | Berkeley Lake | Denver | F | 1 ft | - | 77 |
| 4 | Nee Noshe Reservoir | Kiowa | F | 1.2 ft | - | 74 |
| 5 | Turks Pond | Baca | F | 0.7 ft | - | 83 |
| 6 | Lake Henry | Crowley | F | 1.3 ft | - | 73 |
| 7 | Arkansas Lake | El Paso | F | - | - | 89 |
| 8 | Arkansas Lake | Prowers | F | - | - | 78 |
All hypereutrophic lakes →Minnesota version →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 →North Carolina version →All Colorado lakes →
Source: EPA National Aquatic Resource Surveys, 2026.