The Town boundaries shall be as they existed immediately prior to the effective date of this section, subject to all rights, reservations, limitations, and conditions as may be set forth in all prior resolutions of annexation and in the Charter of the Town in effect immediately prior to the effective date of this section, and as they may be hereafter amended as provided by law. A description of the corporate boundaries shall be maintained on file by the Director of Administration. There shall be an official survey map of the Town boundaries approved by the Commissioners of Bel Air and in the custody of the Director of Public Works.