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LakeQuality

South Turtle Lake in Otter Tail County, Minnesota has nutrient and algae measurements on record from state and federal monitoring. A water-quality reading is not a swimming clearance. The state water agency and county health departments post current advisories; check them before you swim.. 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

MetricValue
Water Clarity (Secchi Depth)14.1 ft
Phosphorus20 μg/L
Chlorophyll-a (Algae)3.7 μg/L
Maximum Depth35 ft
LocationOtter Tail County, Minnesota

How does South Turtle Lake compare?

With an overall water-quality readings of , South Turtle Lake matches or beats the Minnesota state average. 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.