Lower Twin Lake

On the LakeGrade rubric Lower Twin Lake fails the cutoffs — a TSI of 69 and persistent algal pressure put it in the bottom tier. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Within Freeborn County's 4 graded lakes, Lower Twin Lake ranks 3 — below the local median, though not at the bottom.

No invasive species are currently listed at Lower Twin Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Lower Twin Lake, which usually reflects a lack of formal fisheries survey work rather than an empty 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.