Clearwater Lake vs South Long Lake
Water quality, depth, fish species, and recreation comparison.
Clearwater Lake has a higher water quality grade (A, Excellent) than South Long Lake (C, Fair). Both are in Crow Wing County, Minnesota.
Clearwater Lake and South Long Lake are both in Minnesota — 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: Clearwater Lake grades a A while South Long 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 — Clearwater 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?
Clearwater Lake
Good clarity, visible to about 13 ft.
South Long Lake
Moderate clarity, visible to about 9 ft.
Side-by-Side Metrics
| Metric | Clearwater Lake | South Long Lake |
|---|---|---|
| Overall Grade | A (Excellent) | C (Fair) |
| Water Clarity | 13 ft | 9 ft |
| Phosphorus | 12 µg/L | 24 µg/L |
| Chlorophyll-a (Algae) | 3.7 µg/L | 8.8 µg/L |
| Maximum Depth | 54 ft | 47 ft |
| Surface Area | 905 acres | 1,309 acres |
| Public Access | Yes | Yes |
| Fish Species | 16 | 17 |
| Trophic State | mesotrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Clearwater Lake wins on overall water quality with a Grade A versus South Long Lake's Grade C. Water clarity: 13 ft vs 9 ft. For more fish-species variety, South Long Lake edges ahead with 17 documented species.
Source: EPA National Aquatic Resource Surveys, 2026.