Temperance Lake

Temperance Lake earns an F: 173 µg/L of phosphorus and clarity at 0.7 ft signal heavy nutrient loading from the surrounding watershed. 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.

Hypereutrophic conditions mean the lake is operating at the upper end of the productivity scale, with all the bloom risk that implies. At only 5 ft deep, Temperance Lake is shallow — wind keeps the water column mixed and sediment resuspension drives phosphorus levels harder to manage. Temperance Lake covers 166 acres alongside 2.2 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within the 14 graded lakes of Martin County, Temperance Lake sits at rank 14, near the bottom of the county list.

No invasive species are currently listed at Temperance Lake — the lake remains off the Minnesota infested-waters roster. Bass fishing is part of the appeal: the species list runs to 10, anchored by largemouth and/or smallmouth bass. Public access is available — the lake is on the Minnesota PCA public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.