Is Lake St. Louis by Dam Safe for Swimming?
Lake St. Louis by Dam in St. Charles County, Wisconsin has a water quality grade of F (Very Poor). Avoid swimming, very poor water quality, potential algae toxins. Water clarity: 2.3 ft visibility. Phosphorus: 74.8 µg/L. Chlorophyll-a (algae): 32.2 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | F (Very Poor) |
| Water Clarity (Secchi Depth) | 2.3 ft |
| Phosphorus | 74.8 μg/L |
| Chlorophyll-a (Algae) | 32.2 μg/L |
| Location | St. Charles County, Wisconsin |
How does Lake St. Louis by Dam compare?
With an overall water quality grade of F, Lake St. Louis by Dam falls below the Wisconsin state average of Grade C. It ranks #9 of 11 lakes in St. Charles County by water quality score.
Water clarity (Secchi depth) sits at 2.3 feet. That signals heavy algae or sediment, often tied to high phosphorus from runoff. Algae levels (chlorophyll-a) measure 32.2 µg/L — elevated; risk of harmful algal bloom advisories increases at this concentration.