undertake, without cost to the United States, all alterations of highways made necessary because of the construction of reservoirs and meet all damages because of such highway alterations; and
furnish, without cost to the United States, all lands and easements necessary to the construction of levees and drainage ditches.
(June 15, 1936, ch. 548, § 4, 49 Stat. 1509; Aug. 28, 1937, ch. 877, § 6, 50 Stat. 880; July 26, 1947, ch. 343, title II, § 205(a), 61 Stat. 501.)