Birch Lake

Birch Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Oneida County. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI value of 28 puts Birch Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. The lake bottoms out at 27 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Birch Lake covers 198 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within Oneida County's 140 graded waters, Birch Lake sits at rank 4, near the top of the local distribution.

An invasive species record — Chinese Mystery Snail — has been logged at Birch Lake; Wisconsin DNR maintains the official infested-waters list. Walleye are documented at Birch Lake, one of 5 fish species on record for the lake. 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.