Cleanest Lakes in Johnson County, Illinois
Vienna Correctional Center Lake in Johnson County leads the rankings with a water quality grade of C and 4.5 ft of clarity. Below are the top 2 cleanest monitored lakes in Johnson County, Illinois, ranked by EPA water quality score.
Ranked List
| # | Lake | County | Grade | Clarity | Phosphorus | Algae |
|---|---|---|---|---|---|---|
| 1 | Vienna Correctional Center Lake | Johnson | C | 4.5 ft | 20 µg/L | - |
| 2 | Dutchman Lake | Johnson | D | 2.1 ft | 37.5 µg/L | - |