Thomas J. O'brien Lock And Controlling Works
High HazardNot Available ConditionEmergency Action Plan: Yes
Location
| State | Illinois |
| County | Cook |
| Nearest City | CHICAGO |
| River/Stream | CALUMET RIVER |
| Coordinates | 41.65214, -87.56711 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 37 ft |
| Dam Length | 430 ft |
| Year Completed | 1960 (66 years old) |
Storage & Hydraulics
| NID Storage | 9,700 acre-ft |
| Max Storage | 9,700 acre-ft |
| Drainage Area | 250 sq mi |
| Max Discharge | 2,200 cfs |
| Spillway Type | None |
Ownership & Safety
| Purpose | Navigation |
| Owner | USACE - Chicago District |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 04/05/2022 |
| Emergency Action Plan | Yes |