Lake of the Isles

The LakeGrade rubric puts Lake of the Isles at a C: clarity at 4.9 ft, 52 µg/L of phosphorus, and a TSI of 58 signal an intermediate trophic state. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

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. Lake of the Isles reaches 31 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. The lake's 114 acres and 3.4 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Lake of the Isles ranks 32 of 95 in Hennepin County — solidly in the upper half of the local distribution.

Eurasian watermilfoil has been documented at Lake of the Isles, requiring shoreline management to keep dense mats from crowding native vegetation. Walleye are documented at Lake of the Isles, one of 14 fish species on record for the lake. The lake lacks a documented public access point, so visitor use is limited. Ice-out has been logged at Lake of the Isles more than two dozen times, putting the median around Apr 6 — a useful baseline for tracking climate trends. 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.