Lake Kegonsa

Lake Kegonsa carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

At a TSI of 52, Lake Kegonsa reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. A maximum depth of 32 ft puts Lake Kegonsa in the middle of Wisconsin's depth distribution. Lake Kegonsa covers 3,200 acres alongside partial shoreline records, large enough that conditions can vary meaningfully between bays. Among the 23 graded lakes in Dane County, Lake Kegonsa ranks 5 — in the top quartile locally.

Zebra mussels have been documented at Lake Kegonsa, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. The fishery includes walleye alongside the lake's other 7 documented species — a notable draw for Wisconsin anglers. 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.