Neptune Lake

On the scoring rubric Neptune Lake grades a D: clarity at 6.6 ft and phosphorus readings still being added keep it in the lower bracket for Oneida County. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

At a TSI of 50, Neptune Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. At only 7 ft deep, Neptune Lake is shallow — wind keeps the water column mixed and sediment resuspension drives phosphorus levels harder to manage. The lake's 127 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, Neptune Lake sits at rank 139, near the bottom of the county list.

No invasive species are currently listed at Neptune Lake — the lake remains off the Wisconsin infested-waters roster. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. 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.