A
Island Lake -
Oconto County, Wisconsin
Water Quality Grade: A — Excellent
Crystal clear — you can see 23.0 feet down. Phosphorus level: 21.5 µg/L.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7 m | A |
| Phosphorus | 21.5 µg/L | B |
| Chlorophyll-a (Algae) | No data |
County Ranking
Ranked #105 of 167 lakes in Oconto County
Data Sources
Data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2025-11-13
Monitoring stations: 1