Iowa County Lake Quality
Wisconsin, 7 lakes, average grade D (Poor)
Iowa 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. The county-wide average grade is D — water quality issues are persistent across most of the monitored basins. 3 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. Iowa Lk2 Lake (D) is the cleanest in the county.
Quick Answers for Iowa County
Planning a trip? Check special fishing regulations for Iowa Lk2 Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Iowa County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Iowa Lk2 Lake | D | 3.7 ft | - | - |
| 2 | Iowa Lkt Lake | D | 3.7 ft | - | - |
| 3 | Lake Iowa Park Beach | D | 3.4 ft | - | - |
| 4 | Iowa Lk1 Lake | D | 3.7 ft | - | - |
| 5 | Lake Iowa | F | 1.9 ft | - | - |
| 6 | Iowa Lk3 Lake | F | 3.1 ft | - | - |
| 7 | Iowa Lk4 Lake | F | 3.1 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.