Before any such contract or contracts shall be made by the governing body of such contracting city, or bonds issued, taxes levied or improvements made, as provided in this act, the governing body of such contracting city shall enact an ordinance authorizing the acquisition of the necessary site and the necessary easements, authorizing the making of such improvements and authorizing the making of such contract or contracts. The ordinance shall specify the nature and extent of the improvement to be made and describe such contract or contracts, including the estimated expenditures of the city under such agreement. Such ordinance shall be published once each week for two consecutive weeks in the official city paper. If within thirty (30) days of its last publication a petition signed by not less than five percent (5%) of the legally qualified electors is filed with the city clerk, such ordinance shall not take effect until submitted to the electors of such city and approved at an election to be held within ninety (90) days of the filing of such petition. The governing body of the municipality shall have power to call such an election, and such an election shall be called, noticed, conducted, and canvassed in the manner provided by law for bond elections under the provisions of the general bond law, except, the ballots used when voting upon said ordinance or resolution, as the case may be, shall contain these words: “For the ordinance” and “against the ordinance,” as the case may be (stating the nature of the proposed ordinance). If no sufficient protest is filed within such thirty (30) days, or if the ordinance is approved at an election hereunder, such ordinance shall become effective and the governing body of such city may proceed with its implementation.