A blast from the past: Pittsburgh District completes first demol
Two towboats lock downstream for the last time while the dam is intact before the U.S. Army Corps of Engineers Pittsburgh District conducts the first controlled demolition to breach the fixed-crest dam at the Monongahela River Locks and Dam 3 near Elizabeth, Pennsylvania, July 10, 2024. Removing the dam will create a continuous pool of riverway stretching 30 miles from Charleroi to Braddock, Pennsylvania, improving navigation on the Lower Monongahela River. The dam’s removal work will continue through December. Until the Corps removes the entire dam and verifies the navigation channel is safe, all traffic must pass through the landside lock. After the initial demolition, contractors will perform additional demolitions once per week, requiring the locks to close for three hours or less. The demolition will require 13 more controlled explosions, taking down the rest of the dam in 50-foot sections. The contractor will use excavators on barges to remove the rubble from the river. After the dam is removed and the riverway is cleared, waterway users can navigate through the area without using the lock chambers. The river is anticipated to reopen by the end of 2024. The Pittsburgh District will then move onto the next phase of removing the lock walls in 2025, with work expected to last until 2027. The demolition is part of the Lower Monongahela River Project. Once complete, the project is expected to bring an economic benefit of $200 million annually, including cost-time savings in transporting commodities through the region using inland navigation and reduced maintenance costs. The Monongahela River Locks and Dam 3 has been operating since 1907, but the facility is prone to flooding and shuts down operations during high-water events, resulting in navigation delays. The U.S. Coast Guard supported by establishing restriction zone 1,500 feet up and downstream of the dam. (U.S. Army Corps of Engineers Pittsburgh District photo by Michel Sauret)