When a sidewalk or sidewalks has or have been constructed and where special assessments must be levied for the expense thereof, the governing body shall, as soon as the cost is ascertained, levy an assessment against the lots or pieces of land chargeable therefor, by ordinance, and the property owner shall have thirty (30) days after the publication of the ordinance within which to make full payment of the assessment. The city clerk shall mail a notice not less than fifteen (15) days prior to the end of the thirty (30) days to the owner of the property as shown on the records of the office of the register of deeds, but failure of the owner to receive notice shall not affect the validity of the assessment. The governing body of said city may issue bonds in the manner provided in the general bond law to finance the unpaid balance of any such special assessments.