Watts Lake

On the LakeGrade scale Watts Lake grades a B, with clarity at 23.0 ft and 43 µg/L of phosphorus placing it above the Wisconsin median. Of the three parameters, phosphorus is the worst — at 43 µg/L of phosphorus, it keeps the lake susceptible to algal blooms in warm years.

A TSI near 45 places Watts Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. Watts Lake reaches 31 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. Watts Lake is small — 6 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Among the 9 graded lakes in Ozaukee County, Watts Lake sits at rank 4, above the county median.

Watts Lake has no invasive species recorded in Wisconsin state databases as of 2025, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Watts Lake, which usually reflects a lack of formal fisheries survey work rather than an empty 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.