Upper Genesee Lake

Upper Genesee Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI value of 20 puts Upper Genesee Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. At 32 acres, Upper Genesee Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Upper Genesee Lake ranks 16 of 48 in Waukesha County — solidly in the upper half of the local distribution.

Upper Genesee 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. The fishery is bass-led, with 3 documented species across the lake's records. Public access is available — the lake is on the Wisconsin DNR public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.