How Clean Is Delavan Lake?
Delavan 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): 8.9 ft. Phosphorus: 52.5 µg/L. Chlorophyll-a (algae): 9.1 µg/L. Trophic State Index: 53.
Cleanliness Snapshot
| Metric | Delavan Lake | Wisconsin avg |
|---|---|---|
| Overall Grade | C | B |
| Water Clarity (Secchi) | 8.9 ft | — |
| Phosphorus | 52.5 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 9.1 µg/L | <10 = clean |
| Trophic State Index | 53 | <50 = clean |
How does Delavan Lake compare?
Delavan Lake's grade of C falls below the Wisconsin state average of B. It ranks #14 of 19 lakes in Walworth County by water quality score. Multi-year monitoring data shows water quality is stable based on 7 years of records.
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