How Clean Is Jefferson Lake?
Jefferson Lake has very poor water quality and a high algae bloom risk. It received a water quality grade of F (Very Poor) based on EPA monitoring data. Water clarity (Secchi depth): 2 ft. Phosphorus: 90 µg/L. Trophic State Index: 68.
Cleanliness Snapshot
| Metric | Jefferson Lake | Minnesota avg |
|---|---|---|
| Overall Grade | F | C |
| Water Clarity (Secchi) | 2 ft | — |
| Phosphorus | 90 µg/L | <30 = clean |
| Trophic State Index | 68 | <50 = clean |
How does Jefferson Lake compare?
Jefferson Lake's grade of F falls below the Minnesota state average of C. It ranks #12 of 14 lakes in Le Sueur County by water quality score. Multi-year monitoring data shows water quality is improving based on 4 years of records.