May 19, 2022
The U.S. Navy is undertaking a superflood basin design and construction at the Portsmouth Naval Shipyard in Kittery, Maine. The 3.5-acre super flood basin is being built in front of an existing dry dock that artificially raises the water level in the river. Initially constructed for World War II-era submarines, the floor of the Dry Dock 1 is too shallow for current operational requirements. Presently, the shipyard provides artificial ballast and is tidally restricted to only a handful of days per month for docking and undocking evolutions at Dry Dock 1, which is not sustainable in the long term.