Newton Lake

On the scoring rubric Newton Lake grades a D: clarity at 4.5 ft and phosphorus readings still being added keep it in the lower bracket for Lake 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 55, Newton Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. Newton Lake reaches 47 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. The lake's 516 acres and 12.1 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Within the 142 graded lakes of Lake County, Newton Lake sits at rank 132, near the bottom of the county list.

Newton Lake has at least one documented invasive species (spiny waterflea), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. Walleye are documented at Newton Lake, one of 8 fish species on record for the lake. The lake lacks a documented public access point, so visitor use is limited. 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.