Chippewa Flowage Lake vs Lac Courte Oreilles Lake
Water quality, depth, fish species, and recreation comparison.
Lac Courte Oreilles Lake has a higher water quality grade (A, Excellent) than Chippewa Flowage Lake (C, Fair). Both are in Sawyer County, Wisconsin.
Chippewa Flowage Lake and Lac Courte Oreilles 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. Lac Courte Oreilles Lake (A) is materially cleaner than Chippewa Flowage 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 — Lac Courte Oreilles 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?
Chippewa Flowage Lake
Moderate clarity, visible to about 6.9 ft.
Lac Courte Oreilles Lake
Good clarity, visible to about 12.2 ft.
Side-by-Side Metrics
| Metric | Chippewa Flowage Lake | Lac Courte Oreilles Lake |
|---|---|---|
| Overall Grade | C (Fair) | A (Excellent) |
| Water Clarity | 6.9 ft | 12.2 ft |
| Phosphorus | 26 µg/L | 15 µg/L |
| Chlorophyll-a (Algae) | 7 µg/L | 1.7 µg/L |
| Maximum Depth | 92 ft | 90 ft |
| Surface Area | 14,593 acres | 5,139 acres |
| Public Access | Yes | Yes |
| Fish Species | 8 | 6 |
| Trophic State | eutrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Lac Courte Oreilles Lake wins on overall water quality with a Grade A versus Chippewa Flowage Lake's Grade C. Water clarity: 12.2 ft vs 6.9 ft. For more fish-species variety, Chippewa Flowage Lake edges ahead with 8 documented species.
Source: EPA National Aquatic Resource Surveys, 2026.