How Clean Is Red Rock Lake?
Red Rock Lake has fair water quality — typical of lakes with moderate nutrient enrichment. It received a water quality grade of C (Fair) based on EPA monitoring data. Water clarity (Secchi depth): 3.6 ft. Phosphorus: 53.5 µg/L. Trophic State Index: 60.
Cleanliness Snapshot
| Metric | Red Rock Lake | Minnesota avg |
|---|---|---|
| Overall Grade | C | C |
| Water Clarity (Secchi) | 3.6 ft | — |
| Phosphorus | 53.5 µg/L | <30 = clean |
| Trophic State Index | 60 | <50 = clean |
How does Red Rock Lake compare?
Red Rock Lake's grade of C matches or beats the Minnesota state average of C. It ranks #41 of 51 lakes in Douglas County by water quality score. Multi-year monitoring data shows water quality is declining based on 5 years of records.