Geneva Lake

Geneva Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Walworth County. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Trophically, Geneva Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. At 135 ft of maximum depth, Geneva Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. With 5,401 acres of surface and partial shoreline records, Geneva Lake is a large water by Wisconsin standards — recreational pressure is spread across a long shoreline. Within Walworth County's 35 graded waters, Geneva Lake sits at rank 2, near the top of the local distribution.

Geneva Lake is on the Wisconsin infested-waters list for zebra mussels — boaters should follow clean-drain-dry protocols when moving gear to or from the lake. Walleye are documented at Geneva Lake, one of 6 fish species on record for the lake. A documented public access point at Geneva Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.