Is Red Rock Lake Safe for Swimming?
Red Rock Lake in Douglas County, Minnesota has a water quality grade of F (Very Poor). Avoid swimming, very poor water quality, potential algae toxins. Water clarity: 3.6 ft visibility. Phosphorus: 55 µg/L. Chlorophyll-a (algae): 33.7 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | F (Very Poor) |
| Water Clarity (Secchi Depth) | 3.6 ft |
| Phosphorus | 55 μg/L |
| Chlorophyll-a (Algae) | 33.7 μg/L |
| Maximum Depth | 22 ft |
| Location | Douglas County, Minnesota |
How does Red Rock Lake compare?
With an overall water quality grade of F, Red Rock Lake falls below the Minnesota state average of Grade C. It ranks #34 of 37 lakes in Douglas County by water quality score.
Water clarity (Secchi depth) sits at 3.6 feet. That falls into moderate clarity — typical for lakes with some nutrient enrichment. Algae levels (chlorophyll-a) measure 33.7 µg/L — elevated; risk of harmful algal bloom advisories increases at this concentration.