Green Lake

The LakeGrade rubric puts Green Lake at a C: clarity at 4.7 ft, 36 µg/L of phosphorus, and a TSI of 53 signal an intermediate trophic state. Secchi readings are the weakest of the scored parameters, suggesting suspended sediment or algal biomass dominates the optical signal.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. A maximum depth of just 9 ft means sediment-bound phosphorus releases back into the water column whenever wind stirs the bottom — a classic shallow-lake dynamic. The lake is compact at 50 acres, with partial shoreline records and little volume to buffer nutrient inputs. Green Lake ranks 40 of 50 in Sawyer County — at the lower end of the locally monitored distribution.

Green Lake has no invasive species recorded in Wisconsin state databases as of 2021, though prevention practices still apply at all access points. The fishery is bass-led, with 2 documented species across the lake's records. Multiple sampling years from the Wisconsin DNR Citizen Lake Monitoring Network back the grade, so the letter should hold steady absent a major watershed shift.