Koonz Lake

On the LakeGrade rubric, Koonz Lake pulls an A: clarity at 34.5 ft and 12 µg/L of phosphorus put it in the top bracket for Wisconsin. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI value of 33 puts Koonz Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. The lake bottoms out at 40 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. At 20 acres, Koonz Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Koonz Lake ranks 9 of 27 in Shawano County — solidly in the upper half of the local distribution.

Koonz Lake carries an invasive watermilfoil record — boat-launch decontamination and shoreline care matter more here than at uninfested lakes. Walleye are documented at Koonz Lake, one of 4 fish species on record for the lake. A documented public access point at Koonz Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.