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Locks & Dam 4, Monongahela River

Aerial view of Locks & Dam 4, Monongahela River1900 Gibsonton Rd.
Belle Vernon, PA 15012-4514
724-684-8442

Charleroi Locks and Dam is one of nine navigation structures which provide for year-round navigation on the Monongahela River between Pittsburgh, Pa., and Fairmont, W.Va. It maintains a pool for 19.7 miles upstream to Maxwell Lock and Dam just south of Brownsville, Pa.

Location
Charleroi Locks and Dam is located at river mile 41.5 at the city of Charleroi. The lock chambers and operations buildings are situated along the right bank of the river. Road access to the project is from adjacent Pennsylvania Route 906.

Directions to Lock
Take Interstate 70 to Route 906, Exit 18. Turn right (North) onto Route 906 and proceed 1.5 miles to the lock.

History
Construction of Lock and Dam 4 at this present site was begun in 1931 and completed in 1932. After some 35 years of use, a major rehabilitation of the project was completed in 1967. This work involved reconstruction of the dam, which converted it from a fixed crest to a gated dam and raised the pool level 6 feet. Coupled with the construction of the Maxwell Locks and Dam project, the pool raise eliminated the need for old Lock and Dam 5 at Brownsville.

Project Information
Charleroi Locks and Dam consists of two lock chambers and a gated dam. This type of dam is 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.

Charleroi Locks and Dam is part of the Lower Mon Project which has modernized Braddock, is in the process of modernizing Locks and Dam 4, Charleroi, Pa., and will remove Locks and Dam 3, Elizabeth, Pa.