599 Broadway Street
Masontown, PA 15461-0671
Grays Landing Lock and Dam is one of nine navigation structures which provide for year-round navigation on the Monongahela River between Pittsburgh, PA and Fairmont, West Virginia. Grays Landing maintains a pool for 8.8 miles upstream to Point Marion Lock and Dam
Grays Landing Lock and Dam is located at river mile 82 near the community of Grays Landing, Pennsylvania. Access to the lock chamber and operations buildings is on the right descending bank of the Monongahela River off State Route 166 South.
Grays Landing Lock and Dam replaced Lock and Dam 7, which was located three miles upriver from the new project. Construction of the project began in 1988. The lock was completed in March 1993 and the dam in June 1995. Lock 7 was constructed between 1923 - 1926 and replaced the original timber and stone structure built just upstream of Grays Landing, PA, in the late 1800s.
Grays Landing Lock and Dam consists of one lock chamber and a fixed-crest dam. This type of dam is basically a concrete weir or wall across the river which keeps the river channel upriver of the project deep enough for navigation -- at least 9 feet. Water which flows over this type of dam cannot be controlled locally and consequently cannot provide any control over flood waters. An incidental benefit derived from the pool formed by the dam is the availability of a source of municipal and industrial water supply.