How Clean Is Rainy Lake?
Rainy 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): 9.5 ft. Trophic State Index: 45.
Cleanliness Snapshot
| Metric | Rainy Lake | Minnesota avg |
|---|---|---|
| Overall Grade | C | C |
| Water Clarity (Secchi) | 9.5 ft | — |
| Trophic State Index | 45 | <50 = clean |
How does Rainy Lake compare?
Rainy Lake's grade of C matches or beats the Minnesota state average of C. It ranks #85 of 187 lakes in St. Louis County by water quality score. Multi-year monitoring data shows water quality is declining based on 5 years of records.