Every permit issued under the provisions of this chapter shall expire at the end of sixty days following the estimated date of completion as set forth in the permit. If the permittee shall be unable to complete the work within the specified time, he shall, prior to expiration of the permit, present in writing to the City Engineer a request for an extension of time, setting forth therein the reasons for the requested extension. If, in the opinion of the City Engineer, such an extension is necessary, he may be granted additional time for the completion of the work. (Ord. 3411 § 2 (part); April 1, 1975: Ord. 5009 § 6; April 11, 1989.)