Is Green Lake Safe for Swimming?
Green Lake in Isanti County, Minnesota has a water quality grade of C (Fair). Generally safe for swimming, moderate water quality. Water clarity: 5.1 ft visibility. Phosphorus: 44 µg/L. Chlorophyll-a (algae): 11.7 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | C (Fair) |
| Water Clarity (Secchi Depth) | 5.1 ft |
| Phosphorus | 44 μg/L |
| Chlorophyll-a (Algae) | 11.7 μg/L |
| Maximum Depth | 28 ft |
| Location | Isanti County, Minnesota |
How does Green Lake compare?
With an overall water quality grade of C, Green Lake matches or beats the Minnesota state average of Grade C. It ranks #11 of 19 lakes in Isanti County by water quality score.
Water clarity (Secchi depth) sits at 5.1 feet. That falls into moderate clarity — typical for lakes with some nutrient enrichment. Algae levels (chlorophyll-a) measure 11.7 µg/L — moderate; acceptable for swimming on most days, but worth checking advisories.