The proviso in section 702d of this title “That any land acquired under the provisions of this section shall be turned over without cost to the ownership of States or local interests,” shall not apply to the lands heretofore acquired or that may be hereafter acquired in connection with the construction, maintenance, or operation of the Bonnet Carre Spillway and Floodway. The Secretary of the Army is authorized to grant to any citizen, association, railroad, or other corporation, State or public agency thereof, rights-of-way, easements, and permits, over, across, in, and upon said lands for railway, highway, telephone, telegraph, and pipe-line crossings, and other purposes. The grants issued in pursuance of this authority shall be under such terms and conditions as the Secretary of the Army may deem advisable for the protection of the public interests, and may be perpetual or temporary in his discretion.