South Side Detention Basin Berm 1 Dam
South Side Detention Basin Berm 1 Dam is an earth dam located in Coles County, Illinois, built in 2011. It carries a High hazard potential classification.
About South Side Detention Basin Berm 1 Dam
The primary purpose of South Side Detention Basin Berm 1 Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by City Of Mattoon (local government). It impounds the Trib Kickapoo Creek near Mattoon.
The dam stands 12 feet tall and stretches 2,103 feet across, has a maximum storage capacity of 73 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 2011, the structure is relatively new.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. An emergency action plan is in place for this dam. The most recent inspection on record was 12/09/2025.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Illinois dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Illinois |
| County | Coles |
| Nearest City | Mattoon |
| River/Stream | Trib Kickapoo Creek |
| Coordinates | 39.46461, -88.37111 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 12 ft |
| Dam Height | 12 ft |
| Dam Length | 2,103 ft |
| Year Completed | 2011 (15 years old) |
Storage & Hydraulics
| NID Storage | 73 acre-ft |
| Max Storage | 73 acre-ft |
| Drainage Area | 0 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | CITY OF MATTOON |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 12/09/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | IL50636 |
| Federal ID | IL50636 |
| More Info | State Dam Safety Program |