Twin Lake

On the scoring rubric Twin Lake grades a D: clarity at 5.9 ft and 64 µg/L of phosphorus keep it in the lower bracket for Hennepin County. 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.

At a TSI of 58, Twin Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. The lake bottoms out at 44 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Twin Lake covers 217 acres alongside 6.6 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Among the 95 graded lakes in Hennepin County, Twin Lake sits at rank 39, above the county median.

Eurasian watermilfoil has been documented at Twin Lake, requiring shoreline management to keep dense mats from crowding native vegetation. Walleye are documented at Twin Lake, one of 13 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a partial ice record — 5 observed ice-outs, centered near Mar 28. 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.