Cleanest Lakes in Colorado
Crystal Reservoir in Montrose County leads the rankings with a water quality grade of A and 15.4 ft of clarity. Below are the top 12 cleanest monitored lakes in Colorado, ranked by EPA water quality score.
Ranked List
| # | Lake | County | Grade | Clarity | Phosphorus | Algae |
|---|---|---|---|---|---|---|
| 1 | Crystal Reservoir | Montrose | A | 15.4 ft | 15.7 µg/L | - |
| 2 | Lake Granby | Grand | A | 12.7 ft | 17 µg/L | 1.7 µg/L |
| 3 | Pueblo Reservoir | Pueblo | B | 6.7 ft | 10 µg/L | 5 µg/L |
| 4 | Wolford Mountain Reservoir | Grand | B | 8.3 ft | 10 µg/L | 1.9 µg/L |
| 5 | Grand Lake | Grand | B | 8.9 ft | 14 µg/L | 2.7 µg/L |
| 6 | Summit Lake | Jackson | B | 12.1 ft | 20 µg/L | - |
| 7 | Blue Mesa Reservoir | Gunnison | B | 11.5 ft | 35 µg/L | 4.9 µg/L |
| 8 | Windy Gap Reservoir | Grand | B | - | 52.5 µg/L | 3 µg/L |
| 9 | Shadow Mountain Lake | Grand | B | 7.8 ft | 20 µg/L | 5.1 µg/L |
| 10 | Willow Creek Reservoir | Grand | C | 3.9 ft | 87.5 µg/L | 2.4 µg/L |
| 11 | Stagecoach Reservoir | Routt | C | 7.5 ft | 33.5 µg/L | 18.9 µg/L |
| 12 | Prospect Lake | Weld | F | - | 250 µg/L | 42.5 µg/L |