$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.