Bonds or notes issued under the authority of this chapter, except those which are secured only by sewerage system use charges, shall be obligatory upon the municipality and the inhabitants and property thereof according to the tenor and purport of the same and the full faith and credit of the municipality shall be pledged to the payment thereof, whether or not such pledge is stated in the bonds or notes or in the vote authorizing their issuance, and thereafter the municipality shall appropriate in each year during which any such bonds or notes are outstanding, and there shall be available on or before the date when the same are payable, an amount of money which, together with other revenue available for such purpose, shall be sufficient to pay the principal and interest on such bonds or notes payable in that year, and there shall be included in the tax levy for each such year an amount which, together with other revenues available for such purpose, shall be sufficient to meet such appropriation.