How Clean Is Upper South Long Lake?
Upper South Long Lake is a clean lake by Minnesota standards. It received a water quality grade of B (Good) based on EPA monitoring data. Water clarity (Secchi depth): 6 ft. Phosphorus: 17 µg/L. Trophic State Index: 48.
Cleanliness Snapshot
| Metric | Upper South Long Lake | Minnesota avg |
|---|---|---|
| Overall Grade | B | C |
| Water Clarity (Secchi) | 6 ft | — |
| Phosphorus | 17 µg/L | <30 = clean |
| Trophic State Index | 48 | <50 = clean |
How does Upper South Long Lake compare?
Upper South Long Lake's grade of B matches or beats the Minnesota state average of C. It ranks #91 of 120 lakes in Crow Wing County by water quality score. Multi-year monitoring data shows water quality is improving based on 5 years of records.