Nelson Lake

Nelson Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Hubbard County. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

The lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. A maximum depth of 20 ft puts Nelson Lake in the middle of Minnesota's depth distribution. At 40 acres, Nelson Lake sits below the Minnesota median: a small water where shoreline activity has an outsized effect on water quality. Within Hubbard County's 77 graded lakes, Nelson Lake ranks 45 — below the local median, though not at the bottom.

No invasive species are currently listed at Nelson Lake — the lake remains off the Minnesota infested-waters roster. Walleye are documented at Nelson Lake, one of 6 fish species on record for the 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.