If petitions signed by not less than fifteen percent (15%) of the qualified electors voting on the office of mayor in the city at the last preceding general election are filed with the city clerk of the city within forty-five (45) days after the enactment of the ordinance creating the municipal drainage improvement district requesting that the ordinance be referred to a vote of the qualified electors of the district, the petitions shall be referred to the people at a special election to be called by the mayor of the municipality in accordance with § 7-11-201 et seq. to be held not more than ninety (90) days after the proclamation.