Any permittee holding an unexpired grading and excavation permit may apply in writing for an extension of the time within which grading operations are to be commenced or completed. The Development Coordination Office may extend the expiration date of the permit for a period not exceeding 180 days if the permittee presents satisfactory evidence that unusual difficulties have prevented commencement or completion of grading. (Ord. 16432 § 5(4), 3-10-92. Code 1995 § 66-107.)