Chenango County Lake Quality
Wisconsin, 7 lakes, average grade B (Good)
Chenango County has 7 graded lakes — a thin enough sample that one or two stressed lakes can move the county average noticeably. Use the per-lake pages below for what actually matters. With an average grade of B, Chenango County sits comfortably above the New York median.
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 Lake Petonia (A); the most-stressed is Truitt Pond (F).
Quick Answers for Chenango County
Planning a trip? Check special fishing regulations for Lake Petonia, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Chenango County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Lake Petonia | A | 20.2 ft | - | - |
| 2 | Chenango Lake | A | 16.6 ft | - | - |
| 3 | Guilford Lake | B | 13.8 ft | - | - |
| 4 | Warn Lake | B | 14.1 ft | - | - |
| 5 | Genegantslet Lake | B | 12 ft | - | - |
| 6 | Plymouth Reservoir | D | 6.2 ft | - | - |
| 7 | Truitt Pond | F | 3.2 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.