Audrain County Lake Quality
Wisconsin, 4 lakes, average grade C (Fair)
Audrain County has 4 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 average is C — the middle of the rubric, with one or two lakes pulling the average up or down depending on year.
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. Oasis Ranch Lake (A) is the cleanest in the county.
Quick Answers for Audrain County
Planning a trip? Check special fishing regulations for Oasis Ranch Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Audrain County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Oasis Ranch Lake | A | 14.1 ft | - | 8 µg/L |
| 2 | Oasis Ranch Upper Lake | A | 14.4 ft | - | 12 µg/L |
| 3 | Vandalia Community Lake | F | 1.8 ft | - | 110 µg/L |
| 4 | Teal Lake | F | 2 ft | - | 109 µg/L |
Source: EPA National Aquatic Resource Surveys, 2026.