How Clean Is Marion Lake?
Marion Lake has fair water quality — typical of lakes with moderate nutrient enrichment. It received a water quality grade of C (Fair) based on EPA monitoring data. Water clarity (Secchi depth): 7 ft. Trophic State Index: 49.
Cleanliness Snapshot
| Metric | Marion Lake | Minnesota avg |
|---|---|---|
| Overall Grade | C | C |
| Water Clarity (Secchi) | 7 ft | — |
| Trophic State Index | 49 | <50 = clean |
How does Marion Lake compare?
Marion Lake's grade of C matches or beats the Minnesota state average of C. It ranks #12 of 36 lakes in Dakota County by water quality score. Multi-year monitoring data shows water quality is improving based on 3 years of records.