Iosco County Lake Quality
Wisconsin, 8 lakes, average grade B (Good)
Only 8 lakes in Iosco 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. With an average grade of B, Iosco County sits comfortably above the Michigan 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 Hu32 Lake (A); the most-stressed is Van Etten Lake (D).
Quick Answers for Iosco County
Planning a trip? Check special fishing regulations for Hu32 Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Iosco County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Hu32 Lake | A | 46.6 ft | - | - |
| 2 | Hu27 Lake | A | 36.1 ft | - | - |
| 3 | Csmi 2017 Station Mz73 Lake | A | 45.1 ft | - | - |
| 4 | Chain Lakes East Basin | A | 12 ft | - | - |
| 5 | Chain Lakes | B | 12 ft | - | - |
| 6 | Long Lake North Central Basin; Plainfield Township | B | 13 ft | - | - |
| 7 | Van Etten Lake North Central Basin; Oscoda Township | C | 5.5 ft | - | - |
| 8 | Van Etten Lake | D | 5.5 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.