Apple River Flowage Lake

On the scoring rubric Apple River Flowage Lake grades a D: clarity at 5.9 ft and 79 µg/L of phosphorus keep it in the lower bracket for Polk County. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

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. Apple River Flowage Lake reaches 18 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. Apple River Flowage Lake covers 604 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within the 74 graded lakes of Polk County, Apple River Flowage Lake sits at rank 63, near the bottom of the county list.

An invasive species record — Chinese Mystery Snail — has been logged at Apple River Flowage Lake; Wisconsin DNR maintains the official infested-waters list. Bass fishing is part of the appeal: the species list runs to 4, anchored by largemouth and/or smallmouth bass. 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.