(a) The chief administrative officer of the Department of City Planning shall be known as the Director of Planning and shall be appointed and removed as provided in Section 508. The Director shall be chosen on the basis of administrative and technical qualifications, with special reference to actual experience in and knowledge of accepted practice in the field of City planning.
(b) The Director of Planning or his or her designee shall:
(1) prepare the proposed General Plan of the City and proposed amendments to the General Plan;
(2) prepare all proposed zoning and other land use regulations and requirements, including maps of all proposed districts or zones;
(3) make investigations and act on the design and improvement of all proposed subdivisions of land as the advisory agency under the State Subdivision Map Act; and
(4) have those additional powers and duties provided by ordinance.