Is Oldham Lake Safe for Swimming?
Oldham Lake in Monona County, Wisconsin has a water quality grade of C (Fair). Generally safe for swimming, moderate water quality. Water clarity: 5.1 ft visibility. Chlorophyll-a (algae): 8.5 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | C (Fair) |
| Water Clarity (Secchi Depth) | 5.1 ft |
| Chlorophyll-a (Algae) | 8.5 μg/L |
| Location | Monona County, Wisconsin |
How does Oldham Lake compare?
With an overall water quality grade of C, Oldham Lake matches or beats the Wisconsin state average of Grade D. It ranks #1 of 2 lakes in Monona County by water quality score.
Water clarity (Secchi depth) sits at 5.1 feet. That falls into moderate clarity — typical for lakes with some nutrient enrichment. Algae levels (chlorophyll-a) measure 8.5 µg/L — moderate; acceptable for swimming on most days, but worth checking advisories.