Freeborn Lake

The LakeGrade rubric puts Freeborn Lake at a C: clarity at 4.6 ft, 35 µg/L of phosphorus, and a TSI of 55 signal an intermediate trophic state. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. The lake bottoms out at 18 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Freeborn Lake covers 248 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 51 graded lakes of Douglas County, Freeborn Lake sits at rank 44, near the bottom of the county list.

Zebra mussel presence at Freeborn Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. Walleye are documented at Freeborn 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.