The sum of $375,000,000 is hereby authorized to be appropriated for carrying out the improvements herein over the five-year period ending June 30, 1944, and the sum of $10,000,000 additional is authorized to be appropriated and expended in equal amounts by the Departments of the Army and Agriculture for carrying out any examinations and surveys provided for in this Act and any other Acts of Congress, to be prosecuted by said Departments. The sum of $1,500,000 additional is authorized to be appropriated and expended by the Secretary of Energy for carrying out any examinations and surveys provided for in this Act or any other Acts of Congress, to be prosecuted by the said Secretary of Energy.