Is South Turtle Lake Safe for Swimming?
South Turtle Lake in Otter Tail County, Minnesota has a water quality grade of A (Excellent). Excellent for swimming, crystal clear water with minimal algae. Water clarity: 14.1 ft visibility. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 3.7 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | A (Excellent) |
| Water Clarity (Secchi Depth) | 14.1 ft |
| Phosphorus | 20 μg/L |
| Chlorophyll-a (Algae) | 3.7 μg/L |
| Maximum Depth | 35 ft |
| Location | Otter Tail County, Minnesota |
How does South Turtle Lake compare?
With an overall water quality grade of A, South Turtle Lake matches or beats the Minnesota state average of Grade C. It ranks #33 of 66 lakes in Otter Tail County by water quality score.
Water clarity (Secchi depth) sits at 14.1 feet. That counts as exceptional clarity — sunlight penetrates deep, supporting submerged plants and limiting algae. Algae levels (chlorophyll-a) measure 3.7 µg/L — low and well within safe swimming guidelines.