Altoona Lake

Altoona Lake pulls a D on the LakeGrade rubric — phosphorus loading and limited clarity hold it below the Wisconsin average. High phosphorus is the leading drag on the score — likely from upland agriculture, lawn runoff, or in-lake sediment release.

At a TSI of 57, Altoona Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. A maximum depth of 25 ft puts Altoona Lake in the middle of Wisconsin's depth distribution. The lake's 720 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. Within the 3 graded lakes of Eau Claire County, Altoona Lake sits at rank 3, near the bottom of the county list.

An invasive species record — Chinese Mystery Snail — has been logged at Altoona Lake; Wisconsin DNR maintains the official infested-waters list. The fishery includes walleye alongside the lake's other 4 documented species — a notable draw for Wisconsin anglers. Public access is available — the lake is on the Wisconsin DNR public-access list. 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.