Is Big Lake Safe for Swimming?
Big Lake in Carlton County, Minnesota has a water quality grade of B (Good). Good for swimming, clear water with low algae levels. Water clarity: 9.1 ft visibility. Phosphorus: 12 µg/L. Chlorophyll-a (algae): 3.2 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | B (Good) |
| Water Clarity (Secchi Depth) | 9.1 ft |
| Phosphorus | 12 μg/L |
| Chlorophyll-a (Algae) | 3.2 μg/L |
| Maximum Depth | 25 ft |
| Location | Carlton County, Minnesota |
How does Big Lake compare?
With an overall water quality grade of B, Big Lake matches or beats the Minnesota state average of Grade C. It ranks #1 of 33 lakes in Carlton County by water quality score.
Water clarity (Secchi depth) sits at 9.1 feet. That puts the lake in good clarity range, with limited algae interference. Algae levels (chlorophyll-a) measure 3.2 µg/L — low and well within safe swimming guidelines.