Service area creation, alteration, consolidation, or abolition may be proposed by: (1) filing of a petition with the assembly that is signed by a number of voters residing in the proposed service area equal to 25 percent of the number of votes cast in the proposed service area at the preceding general election, or (2) a notice of intent by the assembly to introduce an ordinance. Denial of a petition that proposes the continued existence or creation of a service area requires a supermajority vote of the assembly. Notice of intent by the assembly under this section shall be demonstrated by the introduction of an ordinance.