Demolition process of dam at Monongahela River Locks and Dam 3

The U.S. Army Corps of Engineers Pittsburgh District will demolish the fixed-crest dam at the Monongahela River Locks and Dam 3 near Elizabeth, Pennsylvania, using a series of controlled blasts and excavators on barges.

The U.S. Army Corps of Engineers' contractor will begin the controlled demolition and subsequent removal of the dam beginning July 10, 2024. This date is subject to change based on weather and river conditions.

The controlled demolition will involve explosives, which will restrict navigation activities near the locks and dam facility. Following the initial demolition, the facility will close to waterway traffic for at least three days to allow for the upper and lower pools to level out on the river.

Once the river has leveled, all navigation must lock through the landside chamber until the entire dam is removed and the contractors have cleared the construction area.

It will take approximately six months and several more controlled demolitions, for the contractors to remove the entire dam until December 2024. Once the contractors have removed the dam and cleared the riverway, all waterway users will be able to navigate through the area without using the lock chambers.

The district will begin removing the lock walls in 2025, with the work expected to continue through 2027.

(U.S. Army Corps of Engineers animation by Jake Pope)