Lockport Lock And Controlling Works
Lockport Lock And Controlling Works is a concrete dam located in Will County, Illinois, built in 1933. It carries a High hazard potential classification.
About Lockport Lock And Controlling Works
The primary purpose of Lockport Lock And Controlling Works is navigation. The dam maintains water levels sufficient for boat and barge traffic, supporting commercial or recreational navigation on the waterway. The dam is owned by Usace - Chicago District (federal). It impounds the Chicago Sanitary & Ship Canal near Joliet.
The dam stands 65 feet tall and stretches 1,100 feet across, creates a reservoir covering 2,112 acres, has a maximum storage capacity of 25,000 acre-feet, and collects water from a drainage area of 740 square miles. Completed in 1933, the structure is well-established, with more than 75 years of service.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. An emergency action plan is in place for this dam. The most recent inspection on record was 02/20/2025.
At 65 feet, this dam is taller than 96% of all dams in the United States.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Illinois dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Illinois |
| County | Will |
| Nearest City | Joliet |
| River/Stream | Chicago Sanitary & Ship Canal |
| Coordinates | 41.56893, -88.07805 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 65 ft |
| Dam Length | 1,100 ft |
| Year Completed | 1933 (93 years old) |
Storage & Hydraulics
| NID Storage | 25,000 acre-ft |
| Max Storage | 25,000 acre-ft |
| Surface Area | 2,112 acres |
| Drainage Area | 740 sq mi |
| Max Discharge | 36,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Navigation |
| Owner | USACE - Chicago District |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 02/20/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | IL00007 |
| Federal ID | IL00007 |
| More Info | State Dam Safety Program |