Dahl Lake

Dahl Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. 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.

Trophically, Dahl Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake is compact at 33 acres, with partial shoreline records and little volume to buffer nutrient inputs. Among the 77 graded lakes in Polk County, Dahl Lake sits at rank 20, above the county median.

Dahl Lake has no invasive species recorded in Wisconsin state databases as of 2019, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Dahl Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. 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.