Lower Nemahbin Lake

On the LakeGrade rubric, Lower Nemahbin Lake pulls an A: clarity at 36.1 ft and 11 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. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Among the 48 graded lakes in Waukesha County, Lower Nemahbin Lake sits at rank 23, above the county median.

No invasive species are currently listed at Lower Nemahbin Lake — the lake remains off the Wisconsin infested-waters roster. The state fisheries records do not list documented species for Lower Nemahbin Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.