How Clean Is Big Round Lake?
Big Round 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): 4.9 ft. Phosphorus: 27.6 µg/L. Chlorophyll-a (algae): 21 µg/L. Trophic State Index: 56.
Cleanliness Snapshot
| Metric | Big Round Lake | Wisconsin avg |
|---|---|---|
| Overall Grade | C | C |
| Water Clarity (Secchi) | 4.9 ft | — |
| Phosphorus | 27.6 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 21 µg/L | <10 = clean |
| Trophic State Index | 56 | <50 = clean |
How does Big Round Lake compare?
Big Round Lake's grade of C matches or beats the Wisconsin state average of C. It ranks #47 of 73 lakes in Polk County by water quality score. Multi-year monitoring data shows water quality is improving based on 6 years of records.