Vernor Lake Dam is an earth dam located in Richland County, Illinois, built in 1924. It carries a Significant hazard potential classification.
Dam profile
NID height · 42 ft42 ft tall and 820 ft long, taller than 88% 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 Vernor Lake Dam
The primary purpose of Vernor Lake 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 Olney (local government). It impounds the Trib Fox River near Olney.
The dam stands 42 feet tall and stretches 820 feet across, creates a reservoir covering 45 acres, has a maximum storage capacity of 972 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1924, 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 08/28/2025.
At 42 feet, this dam is taller than 88% 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 | Richland |
| Nearest City | Olney |
| River/Stream | Trib Fox River |
| Coordinates | 38.76407, -88.10301 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 42 ft |
| Dam Height | 42 ft |
| Dam Length | 820 ft |
| Year Completed | 1924 (102 years old) |
Storage & Hydraulics
| NID Storage | 972 acre-ft |
| Max Storage | 972 acre-ft |
| Normal Storage | 900 acre-ft |
| Surface Area | 45 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 221 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | City of Olney |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Not assessed |
| Last Inspection | 08/28/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | IL00793 |
| Federal ID | IL00793 |
| More Info | State Dam Safety Program |