(a) Where the subdivision contains a street, park, school or other public area which is shown upon the official plan as intended for public ownership, all or part of such area shall either be dedicated to the proper public agency or it shall be reserved for acquisition thereby, within a specified period by a purchase or other means and an agreement shall be entered into between the subdivider and the proper public agency regarding the time and method of acquisition and the cost thereof, or an agreement shall be made by the appropriate public agency upon an alternate location that is satisfactory to the Planning Commission.
(b) Due regard shall be shown for the preservation of outstanding natural and cultural features such as scenic spots, watercourses and historic sites.