Clearwater Lake vs Polly Lake
Water quality, depth, fish species, and recreation comparison.
Clearwater Lake has a higher water quality grade (A, Excellent) than Polly Lake (D, Poor). Both are in Lake County, Minnesota.
Both Clearwater Lake and Polly Lake sit in Minnesota. 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: Clearwater Lake grades a A while Polly 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 — 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
Crystal clear, you can see 18 ft down.
Polly Lake
Murky, only visible to about 4.5 ft.
Side-by-Side Metrics
| Metric | Clearwater Lake | Polly Lake |
|---|---|---|
| Overall Grade | A (Excellent) | D (Poor) |
| Water Clarity | 18 ft | 4.5 ft |
| Phosphorus | No data | No data |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | 46 ft | 21 ft |
| Surface Area | 640.18 acres | 485.24 acres |
| Public Access | No | No |
| Fish Species | 0 | 1 |
| Trophic State | oligotrophic | eutrophic |
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 Polly Lake's Grade D. Water clarity: 18 ft vs 4.5 ft. For more fish-species variety, Polly Lake edges ahead with 1 documented species.