Boundaries of the districts as enumerated in Section II of this ordinance are hereby established as shown on the maps on file in the office of the City Clerk, which maps are hereby designed [designated] as the “zoning district maps,” and said maps and all notations, references, and information shown thereon are made as much a part of this ordinance as if the same were set forth in full herein, and said maps shall be updated within a reasonable time to conform to this ordinance upon adoption. It shall be the duty of the City Clerk to keep on file at City Hall authentic copies of said maps and all changes, amendments or additions thereto.