Is Grindstone Lake Safe for Swimming?
Grindstone Lake in Sawyer County, Wisconsin has a water quality grade of A (Excellent). Excellent for swimming, crystal clear water with minimal algae. Water clarity: 57.7 ft visibility. Phosphorus: 14.4 µg/L. Chlorophyll-a (algae): 1.7 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | A (Excellent) |
| Water Clarity (Secchi Depth) | 57.7 ft |
| Phosphorus | 14.4 μg/L |
| Chlorophyll-a (Algae) | 1.7 μg/L |
| Maximum Depth | 60 ft |
| Location | Sawyer County, Wisconsin |
How does Grindstone Lake compare?
With an overall water quality grade of A, Grindstone Lake matches or beats the Wisconsin state average of Grade B. It ranks #2 of 52 lakes in Sawyer County by water quality score.
Water clarity (Secchi depth) sits at 57.7 feet. That counts as exceptional clarity — sunlight penetrates deep, supporting submerged plants and limiting algae. Algae levels (chlorophyll-a) measure 1.7 µg/L — low and well within safe swimming guidelines.