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LakeQuality

Billy Boy Flowage Lake vs Birch Lake

Water quality, depth, fish species, and recreation comparison.

Billy Boy Flowage Lake has a higher water quality grade (A, Excellent) than Birch Lake (D, Poor). Both are in Sawyer County, Wisconsin.

Both Billy Boy Flowage Lake and Birch Lake sit in Wisconsin. A same-state comparison strips out the state-level water-quality regime as a variable: any grade differences here are about the lakes themselves, not the agencies grading them. The grades are meaningfully apart: Billy Boy Flowage Lake grades a A while Birch Lake grades a D. That two-letter spread reflects real underlying differences — different watershed inputs, different depth profiles, or different monitoring rigor.

For a recreational visitor, the wider grade gap is decisive — Billy Boy Flowage Lake is the better water-quality choice. For a researcher, the gap is the interesting part: what is different about the two watersheds, and which of those differences is mutable?

A

Billy Boy Flowage Lake

Sawyer County, Wisconsin

No clarity data.

D

Birch Lake

Sawyer County, Wisconsin

No clarity data.

Side-by-Side Metrics

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

MetricBilly Boy Flowage LakeBirch Lake
Overall GradeA (Excellent)D (Poor)
Water ClarityNo dataNo data
Phosphorus15 µg/L60.3 µg/L
Chlorophyll-a (Algae)No dataNo data
Maximum Depth--
Surface Area8.5K acres2.3K acres
Public AccessUnknownUnknown
Fish Species00
Trophic Statemesotrophiceutrophic

Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).

Verdict

Billy Boy Flowage Lake wins on overall water quality with a Grade A versus Birch Lake's Grade D. For fishing diversity, Billy Boy Flowage Lake also leads with 0 species.