18Total Dams
0High Hazard
7Significant
Dam Safety in Johnson County, Illinois
Johnson County has 18 dams tracked in the National Inventory of Dams. Another 7 carry a significant hazard classification.
The average dam in Johnson County is 55 years old. The most common purpose is recreation. The tallest dam is Little Cache Creek No. 1 at 58 ft.
Explore more: Oldest dams in Illinois · Tallest dams · High risk dams · Largest reservoirs
| Dam | Hazard | Condition | Height (ft) | Purpose | Year |
|---|---|---|---|---|---|
| Little Cache Creek No. 1 | Significant | Not assessed | 58 | Recreation | 1974 |
| Structure No. 12 | Significant | Not assessed | 54 | Recreation | 1974 |
| Lake Como Dam | Significant | Not assessed | 41 | Recreation | 1966 |
| Autumn Rose Lake Dam | Significant | Not assessed | 32 | Recreation | 1998 |
| Cedar Lake Dam | Significant | Not assessed | 24 | Recreation | 1973 |
| Simpson Lake Dam | Significant | Not assessed | 23 | Recreation | 1963 |
| Little Cache Structure 8 Dam | Significant | Not assessed | 21 | Flood Risk Reduction | 1970 |
| Bay Creek Structure 4 Dam | Low | Not assessed | 36 | Flood Risk Reduction | 1977 |
| Little Cache Structure 10 Dam | Low | Not assessed | 36 | Flood Risk Reduction | 1969 |
| Ferne Clyffe Lake Dam | Low | Not assessed | 33 | Recreation | 1960 |
| Lake Thunderhawk Dam | Low | Not assessed | 31 | Recreation | 1975 |
| Little Cache Structure 5 Dam | Low | Not assessed | 31 | Flood Risk Reduction | 1973 |
| Tall Tree Lake Dam | Low | Not assessed | 29 | Recreation | 1964 |
| Vienna Correctional Center Lake Dam | Low | Not assessed | 29 | Recreation | 1964 |
| Vienna Correctional Center W. Lake | Low | Not assessed | 28 | Fish and Wildlife Pond | 1980 |
| Fetter Lake Dam | Low | Not assessed | 24 | Fire Protection, Stock, Or Small Fish Pond | 1958 |
| Lake Echon Dam | Low | Not assessed | 16 | Recreation | 1968 |
| Vienna Reservoir Dam | Low | Not assessed | 13 | Water Supply | 1968 |