Subject to the provisions of Kan. Stat. Ann. § 19-270, whenever line extensions have been laid by any water utility operating under a certificate of convenience and necessity within the original district, within the certificated area as it existed on the effective date of this act and subsequent to the establishment and organization of such water district, the board of such water district shall upon petition of 51% of owners of land within such additional areas enlarge the boundaries of such original water district to include the additional areas in which such line extensions have been laid.