Coffeen Lake Dam
Significant HazardNot Available ConditionEmergency Action Plan: Yes
Location
| State | Illinois |
| County | Montgomery |
| Nearest City | GREENVILLE |
| River/Stream | MC DAVID BRANCH, SHOAL CREEK |
| Coordinates | 39.03516, -89.38671 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 70 ft |
| Dam Height | 70 ft |
| Dam Length | 1,300 ft |
| Year Completed | 1964 (62 years old) |
Storage & Hydraulics
| NID Storage | 35,800 acre-ft |
| Max Storage | 35,800 acre-ft |
| Normal Storage | 22,000 acre-ft |
| Surface Area | 1,096 acres |
| Drainage Area | 19 sq mi |
| Max Discharge | 8,430 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Other |
| Owner | DYNEGY MIDWEST GENERATION, INC. |
| Owner Type | Public Utility |
| Hazard Classification | Significant |
| Condition Assessment | Not Available |
| Last Inspection | 09/17/2025 |
| Emergency Action Plan | Yes |