Lake Decatur Dam
High HazardNot Available ConditionEmergency Action Plan: Yes
Location
| State | Illinois |
| County | Macon |
| Nearest City | DECATUR |
| River/Stream | SANGAMON RIVER |
| Coordinates | 39.82619, -88.95598 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 33 ft |
| Dam Height | 33 ft |
| Dam Length | 1,728 ft |
| Year Completed | 1922 (104 years old) |
Storage & Hydraulics
| NID Storage | 57,520 acre-ft |
| Max Storage | 57,520 acre-ft |
| Normal Storage | 18,420 acre-ft |
| Surface Area | 3,335 acres |
| Drainage Area | 906 sq mi |
| Max Discharge | 64,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Recreation |
| Owner | CITY OF DECATUR |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 09/08/2025 |
| Emergency Action Plan | Yes |