How Clean Is Lake Koshkonong?
Lake Koshkonong 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): 1.7 ft. Phosphorus: 287 µg/L. Trophic State Index: 77.
Cleanliness Snapshot
| Metric | Lake Koshkonong | Wisconsin avg |
|---|---|---|
| Overall Grade | F | C |
| Water Clarity (Secchi) | 1.7 ft | — |
| Phosphorus | 287 µg/L | <30 = clean |
| Trophic State Index | 77 | <50 = clean |
How does Lake Koshkonong compare?
Lake Koshkonong's grade of F falls below the Wisconsin state average of C. It ranks #8 of 8 lakes in Jefferson County by water quality score. Multi-year monitoring data shows water quality is improving based on 4 years of records.