Montgomery Point Lock and Dam

As a result of low water flows on the Mississippi River, movement of vessels using the McClellan-Kerr Arkansas River Navigation System (MKARNS) can be hindered. To correct recurring transportation restrictions, the Montgomery Point Lock and Dam project uses unique hinged crest gates. Normally, gates remain lowered, and the vessels pass over them unimpeded through the navigation pass. But if water levels fall and restrict vessel movement, 10 large, hinged crest gates are raised at the push of a button to maintain minimum navigable depths behind the dam.

With the gates raised, vessels can use the lock chamber to enter or leave the navigation system. Our role in the design and operation of this project included introducing several innovations in the design of the construction cofferdam. We also introduced an innovative ungated spillway, hinged crest gates, and operating equipment—including controls for hinged crest gates and lock gates, gates’ maintenance dewatering system, the control tower, and all electrical and mechanical features.

With the construction of Montgomery Point Lock and Dam and the increased reliability of the MKARNS, it’s estimated that approximately 433,000 trucks were kept off highways. In addition, the project incorporates environmental features that help protect aquatic resources. Hinged crest gates allow fish to pass freely and the need for dredging to remove accumulated silt was decreased by over 90 percent.