Timm Lake

On the LakeGrade rubric Timm Lake fails the cutoffs — a TSI of 67 and persistent algal pressure put it in the bottom tier.

At a TSI of 67, Timm Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. Timm Lake covers 260 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within the 5 graded lakes of Yellow Medicine County, Timm Lake sits at rank 5, near the bottom of the county list.

No invasive species are currently listed at Timm Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Timm 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. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.