(a) No plat of any subdivision shall be qualified for recording in the office of the district magistrate of the State of Alaska or have any validity until it shall have been approved in the manner prescribed herein.

(b) The City Council shall not permit any public improvements over which it has not any control to be made or any money expended for improvements in any area that has been subdivided or upon any street that has been platted, after the date of the adoption of this chapter unless such subdivision or street has been approved in accordance with the provisions contained herein.