How Clean Is Preston Lake?
Preston 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): 5 ft. Phosphorus: 222 µg/L. Chlorophyll-a (algae): 44.1 µg/L. Trophic State Index: 68.
Cleanliness Snapshot
| Metric | Preston Lake | Minnesota avg |
|---|---|---|
| Overall Grade | F | C |
| Water Clarity (Secchi) | 5 ft | — |
| Phosphorus | 222 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 44.1 µg/L | <10 = clean |
| Trophic State Index | 68 | <50 = clean |
How does Preston Lake compare?
Preston Lake's grade of F falls below the Minnesota state average of C. It ranks #1 of 2 lakes in Renville County by water quality score. Multi-year monitoring data shows water quality is improving based on 5 years of records.