Iosco County Lake Quality
Michigan, 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 Chain Lakes East Basin (A); the most-stressed is Van Etten Lake (D).
Quick Answers for Iosco County
Planning a trip? Check special fishing regulations for Chain Lakes East Basin — or check the official Michigan fishing regulations.
All Lakes in Iosco County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | Chain Lakes East Basin | A | 12 ft | - |
| 2 | Chain Lakes | B | 12 ft | - |
| 3 | Long Lake North Central Basin; Plainfield Township | B | 13 ft | - |
| 4 | Van Etten Lake North Central Basin; Oscoda Township | C | 5.5 ft | - |
| 5 | Van Etten Lake | D | 5.5 ft | - |
Other Counties in Michigan
See how Iosco County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 15 states.
Where to stay near Iosco County
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Source: EPA National Aquatic Resource Surveys, 2026.