Northumberland Dam

Northumberland Dam

Originally constructed to power local sawmills, the Northumberland Dam became part of the New York State Canal System in 1822. It was rebuilt to direct water to the old Champlain Canal, forming a navigable pool so boaters could safely cross the Hudson. The dam forms an L-shape that allowed water to flow into the canal while draining excess water down the natural course of the river.

Engineers took advantage of local stone and wood to construct the dam, but the wood decayed rapidly, needing several repairs. A new dam was constructed in 1869. One section at a time, the old dam was removed and replaced with stone and heavy granite blocks.

When engineers designed the Champlain Barge Canal in the early part of the twentieth century, they created a sidecut that severed a section of land that we now know as Lock 5 Island from the mainland. The canalized Hudson River allowed boaters to spend more of their journeys on the river, rather than the separate channel of the old canal. Today the dam continues to provide slack water to enter the canal and ensures adequate water supply to the Lock 5 chamber.