Is Greenwood Lake Safe for Swimming?
Greenwood Lake in Cook County, Minnesota has a water quality grade of A (Excellent). Excellent for swimming, crystal clear water with minimal algae. Water clarity: 15.1 ft visibility. Phosphorus: 10 µg/L. Chlorophyll-a (algae): 2.6 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | A (Excellent) |
| Water Clarity (Secchi Depth) | 15.1 ft |
| Phosphorus | 10 μg/L |
| Chlorophyll-a (Algae) | 2.6 μg/L |
| Maximum Depth | 112 ft |
| Location | Cook County, Minnesota |
How does Greenwood Lake compare?
With an overall water quality grade of A, Greenwood Lake matches or beats the Minnesota state average of Grade C. It ranks #29 of 44 lakes in Cook County by water quality score.
Water clarity (Secchi depth) sits at 15.1 feet. That counts as exceptional clarity — sunlight penetrates deep, supporting submerged plants and limiting algae. Algae levels (chlorophyll-a) measure 2.6 µg/L — low and well within safe swimming guidelines.