Skip to main content
LakeQuality

Is Thomson Reservoir Safe for Swimming?

Thomson Reservoir in Carlton County, Minnesota has a water quality grade of F (Very Poor). Avoid swimming, very poor water quality, potential algae toxins. Water clarity: 3 ft visibility. Always check local health department advisories before swimming.

Key Metrics

MetricValue
Overall GradeF (Very Poor)
Water Clarity (Secchi Depth)3 ft
Maximum Depth22 ft
LocationCarlton County, Minnesota

How does Thomson Reservoir compare?

With an overall water quality grade of F, Thomson Reservoir falls below the Minnesota state average of Grade C. It ranks #32 of 33 lakes in Carlton County by water quality score.

Water clarity (Secchi depth) sits at 3 feet. That falls into moderate clarity — typical for lakes with some nutrient enrichment.