Lake Jacksonville Dam
Lake Jacksonville Dam is an earth dam located in Morgan County, Illinois, built in 1939. It carries a Significant hazard potential classification.
About Lake Jacksonville Dam
The primary purpose of Lake Jacksonville Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by City Of Jacksonville (local government). It impounds the Sandy Creek near Belltown.
The dam stands 54 feet tall and stretches 980 feet across, creates a reservoir covering 477 acres, has a maximum storage capacity of 12,812 acre-feet, and collects water from a drainage area of 10 square miles. Completed in 1939, the structure is well-established, with more than 75 years of service.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. An emergency action plan is in place for this dam. The most recent inspection on record was 04/18/2024.
At 54 feet, this dam is taller than 94% of dams nationwide.
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Location
| State | Illinois |
| County | Morgan |
| Nearest City | Belltown |
| River/Stream | Sandy Creek |
| Coordinates | 39.67151, -90.21631 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 54 ft |
| Dam Height | 54 ft |
| Dam Length | 980 ft |
| Year Completed | 1939 (87 years old) |
Storage & Hydraulics
| NID Storage | 12,812 acre-ft |
| Max Storage | 12,812 acre-ft |
| Normal Storage | 6,099 acre-ft |
| Surface Area | 477 acres |
| Drainage Area | 10 sq mi |
| Max Discharge | 14,582 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | CITY OF JACKSONVILLE |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Not Available |
| Last Inspection | 04/18/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | IL00711 |
| Federal ID | IL00711 |
| More Info | State Dam Safety Program |