Is Hannen Lake Safe for Swimming?
Hannen Lake in Benton County, Wisconsin has a water quality grade of F (Very Poor). Avoid swimming, very poor water quality, potential algae toxins. Water clarity: 1.2 ft visibility. Chlorophyll-a (algae): 119.9 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | F (Very Poor) |
| Water Clarity (Secchi Depth) | 1.2 ft |
| Chlorophyll-a (Algae) | 119.9 μg/L |
| Location | Benton County, Wisconsin |
How does Hannen Lake compare?
With an overall water quality grade of F, Hannen Lake falls below the Wisconsin state average of Grade D. It ranks #1 of 2 lakes in Benton County by water quality score.
Water clarity (Secchi depth) sits at 1.2 feet. That signals heavy algae or sediment, often tied to high phosphorus from runoff. Algae levels (chlorophyll-a) measure 119.9 µg/L — elevated; risk of harmful algal bloom advisories increases at this concentration.