Is Sunnen Lake Safe for Swimming?
Sunnen Lake in Washington County, Wisconsin has a water quality grade of D (Poor). Swimming not recommended, poor water quality with high algae risk. Water clarity: 1 ft visibility. Phosphorus: 61 µg/L. Chlorophyll-a (algae): 14.3 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | D (Poor) |
| Water Clarity (Secchi Depth) | 1 ft |
| Phosphorus | 61 μg/L |
| Chlorophyll-a (Algae) | 14.3 μg/L |
| Location | Washington County, Wisconsin |
How does Sunnen Lake compare?
With an overall water quality grade of D, Sunnen Lake falls below the Wisconsin state average of Grade C. It ranks #2 of 2 lakes in Washington County by water quality score.
Water clarity (Secchi depth) sits at 1 feet. That signals heavy algae or sediment, often tied to high phosphorus from runoff. Algae levels (chlorophyll-a) measure 14.3 µg/L — moderate; acceptable for swimming on most days, but worth checking advisories.