Carroll County Lake Quality
Wisconsin, 1 lakes, average grade B (Good)
Carroll County has 1 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, Carroll County sits comfortably above the Illinois 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 Timber Lake (B); the most-stressed is Timber Lake (B).
Quick Answers for Carroll County
Planning a trip? Check special fishing regulations for Timber Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Carroll County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Timber Lake | B | 11.5 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.