Lake Nellie Dam is an earth dam located in Fayette County, Illinois, built in 1963. It carries a Significant hazard potential classification.
Dam profile
NID height · 41 ft41 ft tall and 460 ft long, taller than 87% of U.S. dams with a recorded height. 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 Lake Nellie Dam
The primary purpose of Lake Nellie 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 South Foek Sugar Creek near Vandalia.
The dam stands 41 feet tall and stretches 460 feet across, creates a reservoir covering 67 acres, has a maximum storage capacity of 1,478 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1963, the structure is well into its service life at over 50 years 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.
At 41 feet, this dam is taller than 87% of dams nationwide.
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 | Vandalia |
| River/Stream | South Foek Sugar Creek |
| Coordinates | 39.05005, -88.85121 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 41 ft |
| Dam Height | 41 ft |
| Dam Length | 460 ft |
| Year Completed | 1963 (63 years old) |
Storage & Hydraulics
| NID Storage | 1,478 acre-ft |
| Max Storage | 1,478 acre-ft |
| Normal Storage | 835 acre-ft |
| Surface Area | 67 acres |
| Drainage Area | 2 sq mi |
| Max Discharge | 6,095 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 | IL00635 |
| Federal ID | IL00635 |
| More Info | State Dam Safety Program |