How Clean Is Blackwater Lake?
Blackwater Lake is among the cleanest lakes in Minnesota. It received a water quality grade of A (Excellent) based on EPA monitoring data. Water clarity (Secchi depth): 14.1 ft. Phosphorus: 12 µg/L. Chlorophyll-a (algae): 4 µg/L. Trophic State Index: 41.
Cleanliness Snapshot
| Metric | Blackwater Lake | Minnesota avg |
|---|---|---|
| Overall Grade | A | C |
| Water Clarity (Secchi) | 14.1 ft | — |
| Phosphorus | 12 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 4 µg/L | <10 = clean |
| Trophic State Index | 41 | <50 = clean |
How does Blackwater Lake compare?
Blackwater Lake's grade of A matches or beats the Minnesota state average of C. It ranks #33 of 104 lakes in Cass County by water quality score. Multi-year monitoring data shows water quality is declining based on 6 years of records.