Big Blake Lake

Big Blake Lake sits at a C on the grading scale — not impaired, not pristine, with summer measurements that vary year to year. 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. Big Blake Lake is a shallow lake at 14 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. The lake's 208 acres and partial shoreline records put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Big Blake Lake ranks 66 of 77 in Polk County — at the lower end of the locally monitored distribution.

An invasive species record — Banded Mystery Snail — has been logged at Big Blake Lake; Wisconsin DNR maintains the official infested-waters list. The fishery includes walleye alongside the lake's other 5 documented species — a notable draw for Wisconsin anglers. A documented public access point at Big Blake Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.