How Clean Is South Twin Lake?
South Twin 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): 10.2 ft. Phosphorus: 13.5 µg/L. Chlorophyll-a (algae): 3.1 µg/L. Trophic State Index: 42.
Cleanliness Snapshot
| Metric | South Twin Lake | Minnesota avg |
|---|---|---|
| Overall Grade | A | C |
| Water Clarity (Secchi) | 10.2 ft | — |
| Phosphorus | 13.5 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 3.1 µg/L | <10 = clean |
| Trophic State Index | 42 | <50 = clean |
How does South Twin Lake compare?
South Twin Lake's grade of A matches or beats the Minnesota state average of C. It ranks #3 of 12 lakes in Mahnomen County by water quality score. Multi-year monitoring data shows water quality is improving based on 2 years of records.