Nelson Lake vs Round Lake
Water quality, depth, fish species, and recreation comparison.
Round Lake has a higher water quality grade (A, Excellent) than Nelson Lake (C, Fair). Both are in Sawyer County, Wisconsin.
Nelson Lake and Round Lake are both in Wisconsin — a same-state head-to-head where the comparison comes down to lake-specific differences in depth, watershed, and monitoring history rather than the broader state-level water-quality regime. The grades are meaningfully apart: Round Lake grades a A while Nelson Lake grades a C. 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 — Round 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?
Nelson Lake
Murky, only visible to about 5 ft.
Round Lake
Crystal clear, you can see 21.1 ft down.
Side-by-Side Metrics
| Metric | Nelson Lake | Round Lake |
|---|---|---|
| Overall Grade | C (Fair) | A (Excellent) |
| Water Clarity | 5 ft | 21.1 ft |
| Phosphorus | 23.9 µg/L | 14.4 µg/L |
| Chlorophyll-a (Algae) | No data | 1 µg/L |
| Maximum Depth | - | 74 ft |
| Surface Area | 2.5K acres | 3.3K acres |
| Public Access | Unknown | Unknown |
| Fish Species | 0 | 0 |
| Trophic State | eutrophic | oligotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Round Lake wins on overall water quality with a Grade A versus Nelson Lake's Grade C. Water clarity: 21.1 ft vs 5 ft. For fishing diversity, Round Lake also leads with 0 species.