Is Johnson Lake Safe for Swimming?
Johnson Lake in St. Louis 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
| Metric | Value |
|---|---|
| Overall Grade | F (Very Poor) |
| Water Clarity (Secchi Depth) | 3 ft |
| Maximum Depth | 18 ft |
| Location | St. Louis County, Minnesota |
How does Johnson Lake compare?
With an overall water quality grade of F, Johnson Lake falls below the Minnesota state average of Grade C. It ranks #184 of 187 lakes in St. Louis 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.