Is Johnson Lake Safe for Swimming?
Johnson Lake in Itasca County, Minnesota has a water quality grade of A (Excellent). Excellent for swimming, crystal clear water with minimal algae. Water clarity: 15.7 ft visibility. Phosphorus: 9 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | A (Excellent) |
| Water Clarity (Secchi Depth) | 15.7 ft |
| Phosphorus | 9 μg/L |
| Maximum Depth | 88 ft |
| Location | Itasca County, Minnesota |
How does Johnson Lake compare?
With an overall water quality grade of A, Johnson Lake matches or beats the Minnesota state average of Grade C. It ranks #26 of 141 lakes in Itasca County by water quality score.
Water clarity (Secchi depth) sits at 15.7 feet. That counts as exceptional clarity — sunlight penetrates deep, supporting submerged plants and limiting algae.