Grass Lake

Grass Lake comes in at a B on the grading rubric — a respectable showing for a Wisconsin lake of its size and depth. Secchi readings are the weakest of the scored parameters, suggesting suspended sediment or algal biomass dominates the optical signal.

A TSI near 45 places Grass Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. At 52 ft of maximum depth, Grass Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. The lake is compact at 90 acres, with partial shoreline records and little volume to buffer nutrient inputs. Grass Lake ranks 9 of 27 in Shawano County — solidly in the upper half of the local distribution.

Grass Lake is on the Wisconsin infested-waters list for zebra mussels — boaters should follow clean-drain-dry protocols when moving gear to or from the lake. Walleye are documented at Grass Lake, one of 6 fish species on record for the lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.