Superior Lake Dam is an earth dam located in Jefferson County, Illinois, built in 1953. It carries a Low hazard potential classification.
Dam profile
NID height · 23 ft23 ft tall and 350 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 Superior Lake Dam
The primary purpose of Superior Lake Dam is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Oak Shores Association (private). It impounds the Trib Big Muddy River near Mount Vernon.
The dam stands 23 feet tall and stretches 350 feet across, and has a maximum storage capacity of 729 acre-feet. Completed in 1953, the structure is well into its service life at over 50 years old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. The most recent inspection on record was 06/02/2025.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Illinois |
| County | Jefferson |
| Nearest City | Mount Vernon |
| River/Stream | Trib Big Muddy River |
| Coordinates | 38.41643, -89.04639 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 23 ft |
| Dam Height | 23 ft |
| Dam Length | 350 ft |
| Year Completed | 1953 (73 years old) |
Storage & Hydraulics
| NID Storage | 729 acre-ft |
| Max Storage | 729 acre-ft |
| Normal Storage | 294 acre-ft |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Oak Shores Association |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Last Inspection | 06/02/2025 |
| Emergency Action Plan | No |
Identifiers
| NID ID | IL00172 |
| Federal ID | IL00172 |
| More Info | State Dam Safety Program |