Unnamed Lake

Unnamed Lake earns a D — measurements through 2023 show persistent nutrient pressure that limits clarity through the summer. High phosphorus is the leading drag on the score — likely from upland agriculture, lawn runoff, or in-lake sediment release.

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. A maximum depth of just 12 ft means sediment-bound phosphorus releases back into the water column whenever wind stirs the bottom — a classic shallow-lake dynamic. Unnamed Lake is small — 51 acres alongside 1.4 miles of shoreline — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Within Polk County's 20 graded lakes, Unnamed Lake ranks 14 — below the local median, though not at the bottom.

Unnamed Lake has no invasive species recorded in Minnesota state databases as of 2023, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Unnamed Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The lake lacks a documented public access point, so visitor use is limited. 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.