St. Elmo Old City Reservoir Dam is an earth dam located in Fayette County, Illinois, built in 1903. It carries a Significant hazard potential classification.
Dam profile
NID height · 23 ft23 ft tall and 715 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About St. Elmo Old City Reservoir Dam
The primary purpose of St. Elmo Old City Reservoir 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 Saint Elmo (local government). It impounds the Brickyard Branch near St.elmo.
The dam stands 23 feet tall and stretches 715 feet across, creates a reservoir covering 25 acres, has a maximum storage capacity of 314 acre-feet, and collects water from a drainage area of 3 square miles. Completed in 1903, the structure is over a century old.
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 04/22/2025.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Illinois |
| County | Fayette |
| Nearest City | St.elmo |
| River/Stream | Brickyard Branch |
| Coordinates | 39.01535, -88.85662 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 23 ft |
| Dam Height | 23 ft |
| Dam Length | 715 ft |
| Year Completed | 1903 (123 years old) |
Storage & Hydraulics
| NID Storage | 314 acre-ft |
| Max Storage | 314 acre-ft |
| Normal Storage | 132 acre-ft |
| Surface Area | 25 acres |
| Drainage Area | 3 sq mi |
| Max Discharge | 2,200 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | City of Saint Elmo |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Not assessed |
| Last Inspection | 04/22/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | IL00631 |
| Federal ID | IL00631 |
| More Info | State Dam Safety Program |