Ontario County Lake Quality
Wisconsin, 3 lakes, average grade B (Good)
Only 3 lakes in Ontario County carry an active grade. The county-level summary is therefore representative of those specific lakes, not necessarily of every water body in the county. The county-wide average lands at B — solid water quality with most lakes carrying clear summer transparency and low-to-moderate phosphorus.
The county's lakes lean shallow, which makes the grades sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest lake on the books is Canandaigua Lake (A); the most-stressed is Honeoye Lake (C).
Quick Answers for Ontario County
Planning a trip? Check special fishing regulations for Canandaigua Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Ontario County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Canandaigua Lake | A | 17.6 ft | - | - |
| 2 | Canadice Lake | A | 18.8 ft | - | - |
| 3 | Honeoye Lake | C | 9.7 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.