Is Cole Lake Safe for Swimming?
Cole Lake in Jefferson County, Wisconsin has a water quality grade of B (Good). Good for swimming, clear water with low algae levels. Water clarity: 18.5 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 16.5 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | B (Good) |
| Water Clarity (Secchi Depth) | 18.5 ft |
| Phosphorus | 17 μg/L |
| Chlorophyll-a (Algae) | 16.5 μg/L |
| Location | Jefferson County, Wisconsin |
How does Cole Lake compare?
With an overall water quality grade of B, Cole Lake matches or beats the Wisconsin state average of Grade C. It ranks #3 of 7 lakes in Jefferson County by water quality score.
Water clarity (Secchi depth) sits at 18.5 feet. That counts as exceptional clarity — sunlight penetrates deep, supporting submerged plants and limiting algae. Algae levels (chlorophyll-a) measure 16.5 µg/L — moderate; acceptable for swimming on most days, but worth checking advisories.