The Secretary is authorized to negotiate for and enter into a contract for the termination of the existing lease of the Hoover Power Plant made pursuant to the Project Act [
43 U.S.C.
617 et seq.], and in the event of such termination the operation and maintenance, and the making of replacements, however necessitated, of the Hoover Power Plant by the United States, directly or through such agent or agents as the Secretary may designate, is authorized. The powers, duties, and rights of such agent or agents shall be provided by contract, which may include provision that questions relating to the interpretation or performance thereof may be determined, to the extent provided therein, by arbitration or court proceedings. The Secretary in consideration of such termination of such existing lease is authorized to agree