T.J. O'Brien Lock and Dam
| T J OBrien Lock and Dam | |
|---|---|
 | |
| Location | South Chicago |
| Opening date | 1960 |
| Construction cost | $6,954,700 |
| Operator(s) |  United States Army Corps of Engineers Rock Island District |
| Dam and spillways | |
| Type of dam | 4 slide gate sections |
| Impounds | Calumet River to Lake Michigan harbor |
| Length | 297 feet |
| Reservoir | |
| Normal elevation | 577 feet above sealevel |
Thomas J. O’Brien Lock & Dam is a lock on the Calumet River on the south side of Chicago. The Calumet River is a tributary to the Chicago Sanitary and Ship Canal. This flows into the Des Plaines River, the Illinois River and then the Mississippi. It is 326 river miles from the Mississippi-Illinois confluence. The up river side of the dam is at Lake Michigan's level, 577 feet above sealevel. The lock dimensions are 1000' x 110' feet.[1]