$272,000,000 is authorized to be appropriated for the carrying out of the modified adopted project, and all unexpended balances of appropriations heretofore made for the prosecution of said flood-control project are made available for the purposes of sections 642a , 702a–1 , 702a–2 to 702a–12 , 702g–1 , 702j–1 , 702j–2 , 702k–1 , and 702k–2 of this title. (June 15, 1936, ch. 548, § 13, 49 Stat. 1513 .)