Green Lake

On the LakeGrade rubric, Green Lake pulls an A: clarity at 13.1 ft and 14 µg/L of phosphorus put it in the top bracket for Minnesota. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. At 110 ft of maximum depth, Green Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. At 5,569 acres, Green Lake is one of the larger lakes in Kandiyohi County, with 12.0 miles of shoreline supporting multiple distinct use patterns. Within Kandiyohi County's 35 graded waters, Green Lake sits at rank 3, near the top of the local distribution.

Zebra mussel presence at Green Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. Green Lake's fishery is anchored by muskellunge, with 22 documented species in total — a destination water for muskie anglers. Public access is available — the lake is on the Minnesota PCA public-access list. Ice-out has been logged at Green Lake more than two dozen times, putting the median around Apr 16 — a useful baseline for tracking climate trends. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.