How Clean Is Green Lake?
Green 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): 13.1 ft. Phosphorus: 66.5 µg/L. Trophic State Index: 52.
Cleanliness Snapshot
| Metric | Green Lake | Wisconsin avg |
|---|---|---|
| Overall Grade | C | B |
| Water Clarity (Secchi) | 13.1 ft | — |
| Phosphorus | 66.5 µg/L | <30 = clean |
| Trophic State Index | 52 | <50 = clean |
How does Green Lake compare?
Green Lake's grade of C falls below the Wisconsin state average of B. It ranks #8 of 13 lakes in Green Lake County by water quality score. Multi-year monitoring data shows water quality is improving based on 2 years of records.