Coles County Lake Quality
Wisconsin, 2 lakes, average grade D (Poor)
Coles County has 2 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. The county-wide average grade is D — water quality issues are persistent across most of the monitored basins. 1 lakes fall into the F bracket outright.
Most of the county's monitored lakes are shallow — under 50 feet — which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed. Charleston Side Channel Lake (D) is the cleanest in the county.
Quick Answers for Coles County
Planning a trip? Check special fishing regulations for Charleston Side Channel Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Coles County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Charleston Side Channel Lake | D | - | - | 61.5 µg/L |
| 2 | Paradise Lake | F | - | - | 139 µg/L |
Source: EPA National Aquatic Resource Surveys, 2026.