Oliver County Lake Quality
Wisconsin, 3 lakes, average grade C (Fair)
Only 3 lakes in Oliver 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. The county average is C — the middle of the rubric, with one or two lakes pulling the average up or down depending on year.
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 Arroda Lake (B); the most-stressed is Nelson Lake (D).
Quick Answers for Oliver County
Planning a trip? Check special fishing regulations for Arroda Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Oliver County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Arroda Lake | B | 6.7 ft | - | - |
| 2 | East Arroda Lake | C | 5.6 ft | - | - |
| 3 | Nelson Lake | D | 1.3 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.