N.C. Gen. Stat. § 160A-543

A city may incur debt under general law to finance services, facilities or functions provided within a service district. If a proposed general obligation bond issue is required by law to be submitted to and approved by the voters of the city, and if the proceeds of the proposed bond issue are to be used in connection with a service that is or, if the bond issue is approved, will be provided only for one or more service districts or at a higher level in service districts than city wide, the proposed bond issue must be approved concurrently by a majority of those voting throughout the entire city and by a majority of the total of those voting in all of the affected or to be affected service districts.