The Secretary of Highways, for the Commonwealth, and the authorities of each municipality may, with the approval of the Water and Power Resources Board, grant easements or flowage rights to the Government of the United States, or any agency thereof, over, and to submerge during the emergency caused by floods or threatened floods, the highways, streets, roads, bridges and lands adjacent thereto which are owned or maintained by the Commonwealth or by the respective municipalities, as the case may be, in any flood area.
32 P.S. § 666.1