Ada Lake

On the scoring rubric Ada Lake grades a D: clarity at 5.5 ft and phosphorus readings still being added keep it in the lower bracket for Cook County.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. A maximum depth of just 13 ft means sediment-bound phosphorus releases back into the water column whenever wind stirs the bottom — a classic shallow-lake dynamic. Ada Lake is small — 23 acres alongside 1.6 miles of shoreline — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Ada Lake ranks 99 of 128 in Cook County — at the lower end of the locally monitored distribution.

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