In those areas and portions of the city where the transmission or distribution facilities of the public utility providing telephone or electric service are underground or hereafter may be placed underground, then a franchisee shall likewise construct, operate and maintain all of its transmission and distribution cable facilities in the same area underground upon city approval. Such undergrounding activities shall be made concurrently and in cooperation with the other affected utilities. Amplifiers and associated equipment in a franchisee’s transmission and distribution lines may be in appropriate housing upon the surface of the ground, accompanied by landscaping and screening approved by the city; provided, however, that city approval of landscaping and screening shall not be unreasonably delayed, withheld or denied. (Ord. 1708 § 1, 1997).