Is Holden City Lake Nr. Dam Safe for Swimming?
Holden City Lake Nr. Dam in Johnson County, Wisconsin has a water quality grade of F (Very Poor). Avoid swimming, very poor water quality, potential algae toxins. Water clarity: 2 ft visibility. Phosphorus: 96 µg/L. Chlorophyll-a (algae): 39.2 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | F (Very Poor) |
| Water Clarity (Secchi Depth) | 2 ft |
| Phosphorus | 96 μg/L |
| Chlorophyll-a (Algae) | 39.2 μg/L |
| Location | Johnson County, Wisconsin |
How does Holden City Lake Nr. Dam compare?
With an overall water quality grade of F, Holden City Lake Nr. Dam falls below the Wisconsin state average of Grade C. It ranks #5 of 5 lakes in Johnson County by water quality score.
Water clarity (Secchi depth) sits at 2 feet. That signals heavy algae or sediment, often tied to high phosphorus from runoff. Algae levels (chlorophyll-a) measure 39.2 µg/L — elevated; risk of harmful algal bloom advisories increases at this concentration.