Willow Lake

Willow Lake comes in at a B on the grading rubric — a respectable showing for a Wisconsin lake of its size and depth. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI near 40 places Willow Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's 410 acres and partial shoreline records put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Within the 140 graded lakes of Oneida County, Willow Lake sits at rank 111, near the bottom of the county list.

Eurasian watermilfoil has been documented at Willow Lake, requiring shoreline management to keep dense mats from crowding native vegetation. Walleye are documented at Willow Lake, one of 5 fish species on record for the lake. 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.