Billy Boy Flowage Lake

Billy Boy Flowage Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. 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.

The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. A maximum depth of 46 ft puts Billy Boy Flowage Lake in the middle of Wisconsin's depth distribution. At 221 acres, Billy Boy Flowage Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Billy Boy Flowage Lake sits at rank 29 of 52 in Sawyer County, in the lower half of the local distribution.

Eurasian watermilfoil has been documented at Billy Boy Flowage Lake, requiring shoreline management to keep dense mats from crowding native vegetation. The fishery includes walleye alongside the lake's other 6 documented species — a notable draw for Wisconsin anglers. 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.