Lake Monona

On the scoring rubric Lake Monona grades a D: clarity at 6.8 ft and 93 µg/L of phosphorus keep it in the lower bracket for Dane County. Of the scored 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 21 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.