Granite Lake South Basin

Granite Lake South Basin pulls a D on the LakeGrade rubric — phosphorus loading and limited clarity hold it below the Wisconsin 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 51, Granite Lake South Basin reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. The lake bottoms out at 34 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Granite Lake South Basin covers 155 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Granite Lake South Basin sits at rank 27 of 37 in Barron County, in the lower half of the local distribution.

Granite Lake South Basin has at least one documented invasive species (Curly-Leaf Pondweed), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. Walleye are documented at Granite Lake South Basin, one of 4 fish species on record for the lake. A documented public access point at Granite Lake South Basin makes the lake usable for shore fishing, paddle craft, and trailered boats. 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.