A sidewalk is hereby declared to be a local improvement and the cost thereof and the expense connected therewith to be paid for by special taxation of the lot, lots and parcels of land contiguous to and abutting on said street and touching upon the line of said improvement according to and in proportion to their frontage on said sidewalk. The levy of such cost shall be made against each lot, lots and parcels of land touching upon the line of said sidewalk, according to its frontage upon said street.
('68 Code, § 6.25)