Elk Lake

On the LakeGrade rubric Elk Lake fails the cutoffs — a TSI of 69 and persistent algal pressure put it in the bottom tier. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

At a TSI of 69, Elk Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. Elk Lake is a shallow lake at 9 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. Elk Lake covers 357 acres alongside 3.5 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within the 24 graded lakes of Sherburne County, Elk Lake sits at rank 22, near the bottom of the county list.

Eurasian watermilfoil is established at Elk Lake, which can dampen recreational access and pressure the native plant community. Walleye are documented at Elk Lake, one of 17 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. Ice-out has been recorded 19 times at Elk Lake, with a median around Apr 13. 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.