Lake County Lake Quality
Wisconsin, 6 lakes, average grade C (Fair)
Only 6 lakes in Lake 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.
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. Middle Lagoon Lake (A) is the cleanest in the county.
Quick Answers for Lake County
Planning a trip? Check special fishing regulations for Middle Lagoon Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Lake County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Middle Lagoon Lake | A | - | - | 14.8 µg/L |
| 2 | Grand Calumet Lagoon Lake | B | - | - | 39 µg/L |
| 3 | Lmg-05 Lake | B | 7.7 ft | - | - |
| 4 | Lmg-05 Lake | D | 1.5 ft | - | - |
| 5 | Umk-13 Lake | D | 4.8 ft | - | - |
| 6 | Lmg-06 Lake | D | 2.8 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.