Coffeen Gmf Gypsum Stack Dam
Illinois — Montgomery County — MCDAVID BRANCH EAST FORK SHOAL
Location
| State | Illinois |
| County | Montgomery |
| River | MCDAVID BRANCH EAST FORK SHOAL |
| Coordinates | 39.07141, -89.39868 |
Physical Characteristics
| NID Height | 108 ft |
| Dam Height | 108 ft |
| Dam Length | 5,100 ft |
| NID Storage | 2,355 acre-ft |
| Max Storage | 2,355 acre-ft |
| Surface Area | 39 acres |
Safety Classification
| Hazard Potential | High |
| Condition Assessment | Not Available |
| EAP Status | Yes |
| Last Inspection | September 17, 2025 |
| Inspection Frequency | 1 |
Dam Information
| Year Completed | — |
| Primary Purpose | Debris Control |
| Dam Type | Earth |
| Owner Type | Public Utility |
| Owner | DYNEGY MIDWEST GENERATION, INC. |
| Other Name | Ameren Coffeen Gmf Gypsum Stack Dam |
Location Map
About This Dam Record
Dam safety data is maintained by the Army Corps of Engineers National Inventory of Dams (NID). High-hazard dams are those where failure could cause loss of life or major property damage downstream.