Monongahela River Locks and Dams 2, 3, and 4 Project (Lower Mon)

Braddock Dam at Dusk       Aerial View of Lock 3, Mon River      Aerial view of Lock and Dam 4, Monongahela River, Charleroi, Pa
  New Braddock Dam
  River Mile 11.3
  Replaced dam originally built in 1906
  Braddock, PA


  Existing Locks and Dam 3
  River Mile 23.8
  Originally built in 1907
  Elizabeth, PA


  Existing Lock and Dam 4
  River Mile 41.5
  Originally built in 1932
  Charleroi, PA


   Project Manager: Steve Frost

Locks and Dams 2, 3 and 4 on the Monongahela River in Allegheny, Washington and Westmoreland counties in southwestern Pennsylvania are the three oldest currently operating-navigation facilities on the Monongahela River. These locks experience the highest volume of commercial traffic on the entire Monongahela River Navigation System and the pools created by these facilities provide industrial and municipal water, and are popular with recreational boaters.

The Lower Mon project replaced the nearly 100 year-old fixed-crest dam at Braddock Locks and Dam with a gated dam, will remove Locks and Dam 3 in Elizabeth and construct two new larger locks (Charleroi Locks) at Locks and Dam 4 in Charleroi.

Current Active Construction:

  • Pool 3 Dredging (completed in March, FY2022)
  • Stilling Basin (anticipated to be complete in FY2022)
  • Charleroi River Chamber and Control Tower (anticipated to be complete in FY2024)