South Long Lake

The LakeGrade rubric puts South Long Lake at a C: clarity at 4.3 ft, 45 µg/L of phosphorus, and a TSI of 58 signal an intermediate trophic state. 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.

A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. The lake bottoms out at 30 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. The lake's 173 acres and 3.9 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. South Long Lake ranks 24 of 49 in Ramsey County — solidly in the upper half of the local distribution.

South Long Lake is on the Minnesota infested-waters list for zebra mussels — boaters should follow clean-drain-dry protocols when moving gear to or from the lake. Walleye are documented at South Long Lake, one of 12 fish species on record for the lake. A documented public access point at South Long Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The lake has a partial ice record — 8 observed ice-outs, centered near Apr 10. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.