How Clean Is Mirror Lake?
Mirror Lake has poor water quality, with elevated phosphorus and algae. It received a water quality grade of D (Poor) based on EPA monitoring data. Water clarity (Secchi depth): 4.6 ft. Phosphorus: 65.4 µg/L. Trophic State Index: 60.
Cleanliness Snapshot
| Metric | Mirror Lake | Wisconsin avg |
|---|---|---|
| Overall Grade | D | C |
| Water Clarity (Secchi) | 4.6 ft | — |
| Phosphorus | 65.4 µg/L | <30 = clean |
| Trophic State Index | 60 | <50 = clean |
How does Mirror Lake compare?
Mirror Lake's grade of D falls below the Wisconsin state average of C. It ranks #8 of 11 lakes in Sauk County by water quality score. Multi-year monitoring data shows water quality is stable based on 6 years of records.