Isabella Lake

On the scoring rubric Isabella Lake grades a D: clarity at 5.8 ft and phosphorus readings still being added keep it in the lower bracket for Lake County.

A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. A maximum depth of 19 ft puts Isabella Lake in the middle of Minnesota's depth distribution. At 1,257 acres, Isabella Lake is one of the larger lakes in Lake County, with 17.1 miles of shoreline supporting multiple distinct use patterns. Isabella Lake ranks 129 of 142 in Lake County — at the lower end of the locally monitored distribution.

Isabella Lake has no invasive species recorded in Minnesota state databases as of 2020, though prevention practices still apply at all access points. Walleye are documented at Isabella Lake, one of 11 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. 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.