How Clean Is Green Lake?
Green Lake is a clean lake by Wisconsin standards. It received a water quality grade of B (Good) based on EPA monitoring data. Water clarity (Secchi depth): 13.3 ft. Phosphorus: 23 µg/L. Trophic State Index: 45.
Cleanliness Snapshot
| Metric | Green Lake | Wisconsin avg |
|---|---|---|
| Overall Grade | B | B |
| Water Clarity (Secchi) | 13.3 ft | — |
| Phosphorus | 23 µg/L | <30 = clean |
| Trophic State Index | 45 | <50 = clean |
How does Green Lake compare?
Green Lake's grade of B matches or beats the Wisconsin state average of B. It ranks #2 of 13 lakes in Green Lake County by water quality score. Multi-year monitoring data shows water quality is declining based on 7 years of records.