Lac Courte Oreilles Lake vs Lake Chetac North Basin
Water quality, depth, fish species, and recreation comparison.
Lac Courte Oreilles Lake has a higher water quality grade (A, Excellent) than Lake Chetac North Basin (D, Poor). Both are in Sawyer County, Wisconsin.
Lac Courte Oreilles Lake and Lake Chetac North Basin 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: Lac Courte Oreilles Lake grades a A while Lake Chetac North Basin 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 — 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?
Lac Courte Oreilles Lake
Good clarity, visible to about 12.2 ft.
Lake Chetac North Basin
No clarity data.
Side-by-Side Metrics
| Metric | Lac Courte Oreilles Lake | Lake Chetac North Basin |
|---|---|---|
| Overall Grade | A (Excellent) | D (Poor) |
| Water Clarity | 12.2 ft | No data |
| Phosphorus | 15 µg/L | 56.3 µg/L |
| Chlorophyll-a (Algae) | 1.7 µg/L | No data |
| Maximum Depth | 90 ft | 26 ft |
| Surface Area | 5,139 acres | 2,400 acres |
| Public Access | Yes | Yes |
| Fish Species | 6 | 5 |
| Trophic State | mesotrophic | eutrophic |
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 Lake Chetac North Basin's Grade D. For fishing diversity, Lac Courte Oreilles Lake also leads with 6 species.
Source: EPA National Aquatic Resource Surveys, 2026.