Amendments to the official zoning maps shall be adopted by ordinance as provided for herein. Promptly after the adoption of an amendment, the director of planning and facilities shall alter or cause to be altered the official zoning maps to indicate the amendment, and shall enter in writing upon the face of the map a certification indicating the alterations and citing the date of adoption and the effective date of the ordinance amending the map. (Ord. 99-O-25 § 1.5, 1999)