33 U.S.C. § 603
Section, acts July 25, 1912, ch. 253, §1, 37 Stat. 222; July 3, 1930, ch. 847, §3, 46 Stat. 946; Oct. 17, 1940, ch. 895, §3, 54 Stat. 1200, related to removal of temporary obstructions and to minor improvements in navigable waters. See section 603a of this title.