How Clean Is Lake St. Louis by Dam?
Lake St. Louis by Dam has very poor water quality and a high algae bloom risk. It received a water quality grade of F (Very Poor) based on EPA monitoring data. Water clarity (Secchi depth): 2.3 ft. Phosphorus: 74.8 µg/L. Chlorophyll-a (algae): 32.2 µg/L. Trophic State Index: 65.
Cleanliness Snapshot
| Metric | Lake St. Louis by Dam | Wisconsin avg |
|---|---|---|
| Overall Grade | F | C |
| Water Clarity (Secchi) | 2.3 ft | — |
| Phosphorus | 74.8 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 32.2 µg/L | <10 = clean |
| Trophic State Index | 65 | <50 = clean |
How does Lake St. Louis by Dam compare?
Lake St. Louis by Dam's grade of F falls below the Wisconsin state average of C. It ranks #9 of 11 lakes in St. Charles County by water quality score.