All charges made to properties connecting to and being served by a sewer line, which charges are made in lieu of assessments for sewer service, shall be collected by the finance director from the owners of the respective properties and deposited in the sewer cumulative reserve fund. Properties which have not been assessed for sewer service or sewer lines or sewer connections shall be charged for the same in lieu of assessments according to the ordinances of the city. (1957 code § 1.36.081.)