Square Lake

Square Lake pulls a D on the LakeGrade rubric — phosphorus loading and limited clarity hold it below the Minnesota average. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. A maximum depth of just 7 ft means sediment-bound phosphorus releases back into the water column whenever wind stirs the bottom — a classic shallow-lake dynamic. The lake's 123 acres and 3.3 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, Square Lake sits at rank 119, near the bottom of the county list.

Square Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. Walleye are documented at Square Lake, one of 7 fish species on record for the lake. No formal public access is documented at Square Lake — most use is by shoreline residents and their guests. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.