A
Birch Lake -
Oconto County, WisconsinLimited Data
Water Quality Grade: A — Excellent
Crystal clear — you can see 29.2 feet down.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.9 m | A |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data |
County Ranking
Ranked #2 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: 2025-10-16
Monitoring stations: 1