Land equal in area to a minimum of 20% of the tract's total land area is set aside for agriculture, open space, common property, conservation, schools, recreation, parks, and land for other public purposes, singly or in combination, except that land utilized for streets, parking, drives and required yards shall not be included as part of the 20%. Lands to be set aside shall be either dedicated to the Township, owned in common by an association as outlined below, or retained in private ownership with appropriate deed restrictions or conservation easements assuring their continued use for the above-stated purposes. At least one-half of the required land to be set aside (10% of the tract's total land area) shall lie outside delineated wetlands, wetland transition areas, and lands which lie within 100 year flood hazard area. Land to be used for open space, recreation or any other public purpose shall be in one functional and contiguous parcel to the maximum extent practicable. The land to be set aside shall be suitable and usable for active recreation and/or other stated purposes as determined by the Township, and shall be concentrated in one part of the site in order to maximize usability. Scattered site and linear arrangements of land to be set aside shall not be permitted unless the Planning Board within its sole discretion makes a finding that such an arrangement is otherwise beneficial and in the public interest.