How Clean Is Grindstone Lake?
Grindstone 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): 17.4 ft. Phosphorus: 14.4 µg/L. Chlorophyll-a (algae): 1.7 µg/L. Trophic State Index: 38.
Cleanliness Snapshot
| Metric | Grindstone Lake | Wisconsin avg |
|---|---|---|
| Overall Grade | A | C |
| Water Clarity (Secchi) | 17.4 ft | — |
| Phosphorus | 14.4 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 1.7 µg/L | <10 = clean |
| Trophic State Index | 38 | <50 = clean |
How does Grindstone Lake compare?
Grindstone Lake's grade of A matches or beats the Wisconsin state average of C. It ranks #5 of 50 lakes in Sawyer County by water quality score. Multi-year monitoring data shows water quality is stable based on 5 years of records.