How Clean Is Rock Lake?
Rock Lake is among the cleanest lakes in Wisconsin. It received a water quality grade of A (Excellent) based on EPA monitoring data. Water clarity (Secchi depth): 12.5 ft. Phosphorus: 17.9 µg/L. Trophic State Index: 43.
Cleanliness Snapshot
| Metric | Rock Lake | Wisconsin avg |
|---|---|---|
| Overall Grade | A | C |
| Water Clarity (Secchi) | 12.5 ft | — |
| Phosphorus | 17.9 µg/L | <30 = clean |
| Trophic State Index | 43 | <50 = clean |
How does Rock Lake compare?
Rock Lake's grade of A matches or beats the Wisconsin state average of C. It ranks #1 of 8 lakes in Jefferson County by water quality score. Multi-year monitoring data shows water quality is improving based on 6 years of records.