(a) When the City initiates an Ordinance for the annexation of property to the City, the Commission shall prepare an Ordinance to amend this Ordinance embracing the proposed zoning provisions to be established for such area proposed to be annexed. Procedure on the proposed Ordinance to amend this Ordinance shall progress concurrently with the procedure on the annexation Ordinance in order that the zoning amendment may be adopted by the City Council at the same time as the annexation Ordinance.
(b) Whenever any Street, Place, Alley, Public Way, Railroad Right-of-way, Waterway, or other similar area is vacated by proper authority, the Districts adjoining each side of such Street, Alley, Public Way, Railroad Right-of way, or similar area shall be extended automatically to the center of such vacation and all area included in the vacation shall then and thenceforth be subject to all appropriate provisions of the extended Districts. In the event of a partial vacation, the adjoining District, or District nearest the portion vacated, shall be extended automatically to include all of the vacated area.