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): 6.2 ft. Phosphorus: 34 µg/L. Chlorophyll-a (algae): 12.3 µg/L. Trophic State Index: 54.
Cleanliness Snapshot
| Metric | Blackduck Lake | Minnesota avg |
|---|---|---|
| Overall Grade | C | C |
| Water Clarity (Secchi) | 6.2 ft | — |
| Phosphorus | 34 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 12.3 µg/L | <10 = clean |
| Trophic State Index | 54 | <50 = clean |
How does Blackduck Lake compare?
Blackduck Lake's grade of C matches or beats the Minnesota state average of C. It ranks #69 of 85 lakes in Beltrami County by water quality score. Multi-year monitoring data shows water quality is improving based on 6 years of records.