The power of Congress with respect to navigable streams is plenary; nothing prevents Congress from 'abating any erections that may have been made, and preventing any others from being made, except in conformity with such regulations as it may impose.' Willamette Iron Bridge Co. v. Hatch, 125 U.S. 1, 12-13, 8 S.Ct. 811, 817, 31 L.Ed. 629 (1888). Responsive to that decision Congress has enacted that 'The creation of any obstruction not affirmatively authorized by Congress, to the navigable capacity of any of the waters of the United States is prohibited; * * *,' 33 U.S.C. § 403.