No general obligation bonds or other evidences of indebtedness, the payment of which is secured wholly or in part by a pledge of any proceeds of general ad valorem property taxes or to which the full faith and credit of a municipality are pledged, shall be issued, except as follows:

A. a county shall so borrow money only for the purpose of erecting necessary public buildings in connection with any project, and in any such case only after the proposition to create such debt shall have been submitted at a general or special election to the qualified electors of the county and approved by a majority of those voting thereon;

B. a city shall so contract any such debt only by an ordinance that shall be irrepealable until the indebtedness therein provided for shall have been fully paid or discharged and that shall specify the purposes to which the funds to be raised shall be applied. No such debt shall be created unless the question of incurring the debt shall, at a regular election for councilmen or other officers of the city, have been submitted to a vote of the qualified electors thereof and a majority of those voting on the question shall have voted in favor of creating the debt; and

C. no municipality shall ever become indebted to an amount in the aggregate, including existing indebtedness, exceeding four percent on the value of the taxable property within the municipality as shown by the last preceding assessment for state or county taxes, but excluding debts contracted by a city for the construction or purchase of a system for supplying water or of a sewer system for the city; and all bonds or obligations issued in excess of that amount shall be void.