Krohns Lake

On the LakeGrade rubric, Krohns Lake pulls an A: clarity at 26.2 ft and 12 µg/L of phosphorus put it in the top bracket for Wisconsin. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

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 38 ft puts Krohns Lake in the middle of Wisconsin's depth distribution. Krohns Lake is small — 19 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Within Kewaunee County's 4 graded waters, Krohns Lake sits at rank 1, near the top of the local distribution.

Eurasian watermilfoil is established at Krohns Lake, which can dampen recreational access and pressure the native plant community. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. A documented public access point at Krohns 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.