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LakeQuality

Is Stanley Reservoir Safe for Swimming?

Stanley Reservoir in Mountrail County, Wisconsin has a water quality grade of D (Poor). Swimming not recommended, poor water quality with high algae risk. Water clarity: 1.1 ft visibility. Chlorophyll-a (algae): 19.5 µg/L. Always check local health department advisories before swimming.

Key Metrics

MetricValue
Overall GradeD (Poor)
Water Clarity (Secchi Depth)1.1 ft
Chlorophyll-a (Algae)19.5 μg/L
LocationMountrail County, Wisconsin

How does Stanley Reservoir compare?

With an overall water quality grade of D, Stanley Reservoir falls below the Wisconsin state average of Grade C. It ranks #5 of 5 lakes in Mountrail County by water quality score.

Water clarity (Secchi depth) sits at 1.1 feet. That signals heavy algae or sediment, often tied to high phosphorus from runoff. Algae levels (chlorophyll-a) measure 19.5 µg/L — moderate; acceptable for swimming on most days, but worth checking advisories.