Any group parking facility with 30 cars or more and, in Residence Districts, any community facility use or enlargement thereof, shall be allowed only by authorization of the City Planning Commission. In order to grant such authorizations, the Commission, upon review of a site plan, shall find that:

(a)        the proposed development, enlargement or site alteration will not adversely affect the drainage pattern and soil conditions of the area;

(b)        the proposed development, enlargement or site alteration has minimal impact on the existing natural topography and vegetation and blends harmoniously with it;

(c)        such development, enlargement or site alteration is so located as not to impair the essential character of the surrounding area;

(d)        the design of such development, enlargement or site alteration takes full advantage of all special characteristics of the site;

(e)        vehicular access and egress for such development, enlargement or site alteration is located and arranged so as to draw a minimum of vehicular traffic to and through local streets in nearby residential areas; and

(f)        where vehicular access and egress is located on an arterial, such location affords the best means for controlling the flow of traffic generated by such development to and from such arterial.

The Commission may permit modifications to parking lot landscaping and maneuverability requirements for applications for such authorizations of group parking facilities for over 30 cars or for enlargements to group parking facilities, if such modifications preserve vegetation and natural topography.