Billy Boy Flowage Lake vs Nelson Lake
Water quality, depth, fish species, and recreation comparison.
Billy Boy Flowage Lake has a higher water quality grade (A, Excellent) than Nelson Lake (C, Fair). Both are in Sawyer County, Wisconsin.
Both Billy Boy Flowage Lake and Nelson 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. Billy Boy Flowage Lake (A) is materially cleaner than Nelson Lake (C). A gap that wide is unlikely to close in a single year of remediation work; it reflects multi-decade differences in the lakes themselves.
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?
Billy Boy Flowage Lake
No clarity data.
Nelson Lake
Murky, only visible to about 5 ft.
Side-by-Side Metrics
| Metric | Billy Boy Flowage Lake | Nelson Lake |
|---|---|---|
| Overall Grade | A (Excellent) | C (Fair) |
| Water Clarity | No data | 5 ft |
| Phosphorus | 15 µg/L | 23.9 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | - | - |
| Surface Area | 8.5K acres | 2.5K acres |
| Public Access | Unknown | Unknown |
| Fish Species | 0 | 0 |
| Trophic State | mesotrophic | eutrophic |
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 Nelson Lake's Grade C. For fishing diversity, Billy Boy Flowage Lake also leads with 0 species.