Lewis Industrial Park Detention Dam is an earth dam located in Jefferson County, Illinois, built in 1999. It carries a Low hazard potential classification.
Dam profile
NID height · 12 ft12 ft tall and 1,900 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 Lewis Industrial Park Detention Dam
The primary purpose of Lewis Industrial Park Detention Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by City of Mount Vernon (local government). It impounds the Trib West Ditch.
The dam stands 12 feet tall and stretches 1,900 feet across, creates a reservoir covering 10 acres, has a maximum storage capacity of 218 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1999, the structure is 27 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 05/27/2025.
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Location
| State | Illinois |
| County | Jefferson |
| Nearest City | None |
| River/Stream | Trib West Ditch |
| Coordinates | 38.32155, -88.96497 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 12 ft |
| Dam Height | 12 ft |
| Dam Length | 1,900 ft |
| Year Completed | 1999 (27 years old) |
Storage & Hydraulics
| NID Storage | 218 acre-ft |
| Max Storage | 218 acre-ft |
| Normal Storage | 74 acre-ft |
| Surface Area | 10 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 90 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | City of Mount Vernon |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Last Inspection | 05/27/2025 |
| Emergency Action Plan | No |
Identifiers
| NID ID | IL50400 |
| Federal ID | IL50400 |
| More Info | State Dam Safety Program |