How Clean Is Birch Lake?
Birch 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): 15 ft. Trophic State Index: 38.
Cleanliness Snapshot
| Metric | Birch Lake | Minnesota avg |
|---|---|---|
| Overall Grade | A | C |
| Water Clarity (Secchi) | 15 ft | — |
| Trophic State Index | 38 | <50 = clean |
How does Birch Lake compare?
Birch Lake's grade of A matches or beats the Minnesota state average of C. It ranks #1 of 6 lakes in Unknown County by water quality score. Multi-year monitoring data shows water quality is declining based on 5 years of records.