Corps completes Elizabeth Dam removal on Lower Mon

A 300-foot navigation channel opened in the former Monongahela Locks and Dam 3 at Elizabeth, Pa., commonly known as Elizabeth Locks and Dam, on December 20, marking a major milestone for the project, said Steve Dine, the Pittsburgh Engineer District’s resident engineer for the Lower Mon Project.

“The entire dam is now removed from the bank, the left abutment all the way to the river wall,” Dine said.

Machinery and gates will be removed in the next couple of months, with controlled blasting for wall removal beginning in the spring, he said. Contractor Joseph B. Fay Company began work January 13 to mechanically demolish portions of the lock walls to 2 feet above the water level. Excavators and jackhammers are being used before explosives remove the rest.
 
Explosive blasts are expected to take place once or twice per week in daytime hours only. A complete river closure 1,500 feet upstream and downstream will be instituted from two hours before to two hours after each blast, with notice of blasting broadcast 24 hours beforehand and on the day of the blast, said Steve Fritz, mega project program manager for Pittsburgh Engineer District.

While the middle and river walls of the locks will be removed to below the river bottom, the wall of the lock adjacent to the riverbank, called the land wall, will remain in place, with a stone berm added for stability of the bank, beneficially using concrete rubble from blasting, Dine said. Fritz added that the abutment from the dam on the opposite side of the river will also stay in place.

Removal of the walls is scheduled for completion by the end of the year, although the full project completion date is set for spring 2027.

The Lower Monongahela Project included replacing the fixed-crest dam at Locks and Dam 2 at Braddock, Pa., with a gated dam, constructing a new, larger lock at Locks and Dam 4 at Charleroi, Pa., which was renamed the John P. Murtha Locks and Dam, and, finally, removing Locks and Dam 3 at Elizabeth.

These were the three oldest operating navigation facilities in the country, according to the Corps of Engineers, and they experienced the highest volume of commercial traffic on the Monongahela River Navigation System.

The Lower Mon Project was first approved by Congress as part of the Water Resources Development Act of 1992, with the first construction funding becoming available in 1995.

The Braddock dam was converted into a gated facility in 2004.

A contract that included the middle wall monoliths for the new chamber at Charleroi was awarded in 2015. The chamber is 84 feet wide by 720 feet long and can fit a nine-barge tow of standard barges or six jumbo barges. It was watered in 2023, and officially opened with the facility renamed in 2024.

The contractor breached the dam at Elizabeth, which was built in 1907, the evening of July 10 last year.

Demolishing the dam created one 30.2-mile pool instead of 12.5 and 17.7-mile pools between the locks and dams at Braddock and Charleroi.

Source: waterwaysjournal