Perch Lake

Perch Lake sits at the top of the Minnesota PCA grading rubric with an A, a mark reached by the cleanest lakes in Minnesota. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. Perch Lake reaches 19 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. Perch Lake is small — 84 acres alongside 2.7 miles of shoreline — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Within Polk County's 21 graded waters, Perch Lake sits at rank 2, near the top of the local distribution.

Perch Lake has no invasive species recorded in Minnesota state databases as of 2025, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Perch Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. No formal public access is documented at Perch Lake — most use is by shoreline residents and their guests. 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.