The standards and requirements of this chapter relating to subdivision regulation may be modified by the city council in the case of a plan for planned development which, in the judgment of the city council provide adequate public spaces and improvements for the circulation, recreation, light, air and service needs of the tract when fully developed and populated, and which also provide such covenants or other legal provisions as will assure conformity to and achievement of the plan. [Code 1975 § 6-5.0306.]