Is Pony Express Lake Safe for Swimming?
Pony Express Lake in DeKalb County, Wisconsin has a water quality grade of D (Poor). Swimming not recommended, poor water quality with high algae risk. Water clarity: 1.3 ft visibility. Phosphorus: 53.2 µg/L. Chlorophyll-a (algae): 26.3 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | D (Poor) |
| Water Clarity (Secchi Depth) | 1.3 ft |
| Phosphorus | 53.2 μg/L |
| Chlorophyll-a (Algae) | 26.3 μg/L |
| Location | DeKalb County, Wisconsin |
How does Pony Express Lake compare?
With an overall water quality grade of D, Pony Express Lake falls below the Wisconsin state average of Grade C. It ranks #1 of 6 lakes in DeKalb County by water quality score.
Water clarity (Secchi depth) sits at 1.3 feet. That signals heavy algae or sediment, often tied to high phosphorus from runoff. Algae levels (chlorophyll-a) measure 26.3 µg/L — elevated; risk of harmful algal bloom advisories increases at this concentration.