33 U.S.C. § 535c

section 491 of this titlesection 535b of this titleProvided, howeverThe approval of the Secretary of the department in which the Coast Guard is operating, as required by , shall be given only subsequent to the President’s approval, as provided for in , and shall be null and void unless the construction of the bridge is commenced within two years and completed within five years from the date of the Secretary’s approval: , That the Secretary, for good cause shown, may extend for a reasonable time either or both of the time limits herein provided.