How Clean Is Big Butternut Lake?
Big Butternut 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): 14.8 ft. Phosphorus: 62.1 µg/L. Trophic State Index: 51.
Cleanliness Snapshot
| Metric | Big Butternut Lake | Wisconsin avg |
|---|---|---|
| Overall Grade | C | B |
| Water Clarity (Secchi) | 14.8 ft | — |
| Phosphorus | 62.1 µg/L | <30 = clean |
| Trophic State Index | 51 | <50 = clean |
How does Big Butternut Lake compare?
Big Butternut Lake's grade of C falls below the Wisconsin state average of B. It ranks #64 of 77 lakes in Polk County by water quality score. Multi-year monitoring data shows water quality is stable based on 6 years of records.