Bonnie Lake

The LakeGrade rubric puts Bonnie Lake at a C: clarity at 8.5 ft, phosphorus readings still being added, and a TSI of 46 signal an intermediate trophic state.

Mesotrophic conditions dominate at Bonnie Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. At only 11 ft deep, Bonnie Lake is shallow — wind keeps the water column mixed and sediment resuspension drives phosphorus levels harder to manage. The lake's 105 acres and 2.5 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Bonnie Lake sits at rank 98 of 142 in Lake County, in the lower half of the local distribution.

Bonnie Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Bonnie Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. No formal public access is documented at Bonnie 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.