East Toqua Lake

East Toqua Lake grades an F: water clarity, phosphorus, and chlorophyll-a all rate poorly, placing it among the most stressed lakes monitored in Minnesota. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

The hypereutrophic status — TSI 85 — reflects sustained heavy nutrient loading from the surrounding watershed and frequent algal pressure. East Toqua Lake is a shallow lake at 9 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. At 437 acres, East Toqua Lake fits the Minnesota median for monitored lakes, with 3.1 miles of shoreline. Within Big Stone County's 9 graded lakes, East Toqua Lake ranks 6 — below the local median, though not at the bottom.

No invasive species are currently listed at East Toqua Lake — the lake remains off the Minnesota infested-waters roster. Walleye are documented at East Toqua Lake, one of 15 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. 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.