Emsworth Locks and Dams is one of six major river facilities on the Ohio River. This facility stands at the head of the Ohio River navigation system and forms a 24-mile pool on the three rivers around the city of Pittsburgh.

Location
Emsworth Locks and main channel dam are located near the towns of Emsworth, Avalon and Ben Avon, PA The back channel dam is located at Neville Island.

History
Construction began at Emsworth in 1919 and continued until 1922, with the locks first opening in September 1921.

The facility replaced three older wicket-type dams which were constructed between 1877 and 1915. They were: the original Lock and Dam 1 on the Ohio River at Davis Island (completed in 1885); the original Lock and Dam 1 on the Allegheny (1902); and Lock and Dam 1 on the Monongahela (1915).

Davis Island Lock and Dam was the first federally built navigation project and served as a model for the 52 wicket dams built on the Ohio River to permit reliable river traffic from Pittsburgh to Cairo, Ill.

The Corps rebuilt and converted the dam to a gated structure between 1935 and 1938. This action raised the pool an additional 7 feet to accommodate larger, more modern barges. From 1981-86, some $30 million was invested in a major rehabilitation of the facility. Rehabilitation included the replacing of electrical systems, operating machinery and buildings and re-surfacing of the lock walls.

Project Information
The Emsworth project consists of two gated dams, one of the two major types in service in the Pittsburgh District. Gated dams are constructed to permit increased control over the water level in the navigation pool upriver of the dam. Machinery mounted on tall concrete piers moves large chains which lift gates that are hinged into the body of the piers. As the gates are raised or lowered to control the amount of water flowing under them, the upstream pool is maintained at a relatively constant level for an authorized depth of at least 9 feet throughout its length. The dam, however, cannot be operated to control flood flows. An incidental benefit derived from the pool formed by the dam is the availability of a source of municipal and industrial water.

Emsworth averages about 550 commercial lockages every month, plus another 350-400 lockages of pleasure craft during the busy summer months.