Circle Lake vs Mazaska Lake
Water quality, depth, fish species, and recreation comparison.
Circle Lake and Mazaska Lake read the same on nutrients and algae. Both are in Rice County, Minnesota.
Both Circle Lake and Mazaska Lake sit in Minnesota. A same-state comparison strips out the state-level water-quality regime as a variable: any differences in the readings here are about the lakes themselves, not the agencies sampling them. The readings are close: Circle Lake and Mazaska Lake sit within a narrow band of each other on phosphorus, chlorophyll-a and clarity. The per-parameter table below shows where the small differences actually live.
With readings this close, the choice between the two lakes turns on non-water-quality factors: depth, fish species, public access, distance from home. The per-lake pages below cover all of those.
Circle Lake
Very murky, less than 1.5 ft of visibility.
Mazaska Lake
Very murky, less than 2.5 ft of visibility.
Side-by-Side Metrics
| Metric | Circle Lake | Mazaska Lake |
|---|---|---|
| Water Clarity | 1.5 ft | 2.5 ft Better |
| Phosphorus | 484.5 µg/L | 89 µg/L Better |
| Chlorophyll-a (Algae) | 59.7 µg/L | 51.3 µg/L Better |
| Maximum Depth | 14 ft | 50 ft Better |
| Surface Area | 838 acres | 688 acres |
| Public Access | Yes | Yes |
| Fish Species | 18 Better | 17 |
| Trophic State | hypereutrophic | eutrophic |
A green ✓ marks the better value for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better). Surface area and trophic state carry no tick — a bigger lake is not a better lake.
Swap a lake
Compare Circle Lake or Mazaska Lake against a different lake.
Verdict
Both lakes earn the same Grade F. The tiebreakers come down to clarity (Circle Lake: 1.5 ft, Mazaska Lake: 2.5 ft) and what you want from the lake. Circle Lake supports more documented fish species.
Source: EPA National Aquatic Resource Surveys, 2026.