Lake Monona

The LakeGrade rubric puts Lake Monona at a C: clarity at 22.1 ft, 93 µg/L of phosphorus, and a TSI of 51 signal an intermediate trophic state. Of the three parameters, phosphorus is the worst — at 93 µg/L of phosphorus, it keeps the lake susceptible to algal blooms in warm years.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. 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. Lake Monona ranks 7 of 23 in Dane County — solidly in the upper half of the local distribution.

No invasive species are currently listed at Lake Monona — the lake remains off the Wisconsin infested-waters roster. The state fisheries records do not list documented species for Lake Monona, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.