Upper Kelly Lake

Upper Kelly Lake sits at a C on the grading scale — not impaired, not pristine, with summer measurements that vary year to year. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI near 45 places Upper Kelly Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 31 ft puts Upper Kelly Lake in the middle of Wisconsin's depth distribution. At 13 acres, Upper Kelly Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Upper Kelly Lake ranks 45 of 48 in Waukesha County — at the lower end of the locally monitored distribution.

Eurasian watermilfoil is established at Upper Kelly Lake, which can dampen recreational access and pressure the native plant community. The fishery is bass-led, with 2 documented species across the lake's records. Public access is available — the lake is on the Wisconsin DNR public-access list. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.