Arrowhead Lake

Arrowhead Lake pulls a D on the LakeGrade rubric — phosphorus loading and limited clarity hold it below the Minnesota average. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

At a TSI of 68, Arrowhead Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. At only 7 ft deep, Arrowhead Lake is shallow — wind keeps the water column mixed and sediment resuspension drives phosphorus levels harder to manage. At 22 acres, Arrowhead Lake sits below the Minnesota median: a small water where shoreline activity has an outsized effect on water quality. Arrowhead Lake sits at rank 54 of 95 in Hennepin County, in the lower half of the local distribution.

Eurasian watermilfoil is established at Arrowhead Lake, which can dampen recreational access and pressure the native plant community. The fishery is panfish-dominated — bluegill, crappie, and sunfish among the 3 species documented for the lake. No formal public access is documented at Arrowhead 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.