Is Alder Lake Safe for Swimming?
Alder Lake in Cook County, Minnesota has a water quality grade of A (Excellent). Excellent for swimming, crystal clear water with minimal algae. Water clarity: 13.8 ft visibility. Phosphorus: 8 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | A (Excellent) |
| Water Clarity (Secchi Depth) | 13.8 ft |
| Phosphorus | 8 μg/L |
| Maximum Depth | 72 ft |
| Location | Cook County, Minnesota |
How does Alder Lake compare?
With an overall water quality grade of A, Alder Lake matches or beats the Minnesota state average of Grade C. It ranks #38 of 128 lakes in Cook County by water quality score.
Water clarity (Secchi depth) sits at 13.8 feet. That counts as exceptional clarity — sunlight penetrates deep, supporting submerged plants and limiting algae.