Napowan Lake

On the LakeGrade rubric, Napowan Lake pulls an A: clarity readings still being added and 11 µg/L of phosphorus put it in the top bracket for Wisconsin. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI value of 39 puts Napowan Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. The lake bottoms out at 18 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. The lake is compact at 52 acres, with partial shoreline records and little volume to buffer nutrient inputs. Napowan Lake ranks 7 of 32 in Waushara County, putting it in the upper tier of locally monitored lakes.

Eurasian watermilfoil has been documented at Napowan Lake, requiring shoreline management to keep dense mats from crowding native vegetation. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. Public access is available — the lake is on the Wisconsin DNR public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.