Is Lake Koshkonong Safe for Swimming?
Lake Koshkonong in Jefferson County, Wisconsin has a water quality grade of F (Very Poor). Avoid swimming, very poor water quality, potential algae toxins. Water clarity: 1.7 ft visibility. Phosphorus: 287 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | F (Very Poor) |
| Water Clarity (Secchi Depth) | 1.7 ft |
| Phosphorus | 287 μg/L |
| Maximum Depth | 7 ft |
| Location | Jefferson County, Wisconsin |
How does Lake Koshkonong compare?
With an overall water quality grade of F, Lake Koshkonong falls below the Wisconsin state average of Grade C. It ranks #8 of 8 lakes in Jefferson County by water quality score.
Water clarity (Secchi depth) sits at 1.7 feet. That signals heavy algae or sediment, often tied to high phosphorus from runoff.