How Clean Is Blackduck Lake?
Blackduck 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): 6.8 ft. Trophic State Index: 50.
Cleanliness Snapshot
| Metric | Blackduck Lake | Minnesota avg |
|---|---|---|
| Overall Grade | C | C |
| Water Clarity (Secchi) | 6.8 ft | — |
| Trophic State Index | 50 | <50 = clean |
How does Blackduck Lake compare?
Blackduck Lake's grade of C matches or beats the Minnesota state average of C. It ranks #107 of 187 lakes in St. Louis County by water quality score. Multi-year monitoring data shows water quality is improving based on 5 years of records.