If, within the time fixed in such notice, as prescribed in Section 13.20.020, such sidewalk or curb or both have not been rebuilt or repaired as required by such notice, then the city engineer shall cause such sidewalk or curb to be rebuilt or repaired and placed in good condition to meet the standards required by the city. The city shall then cause the costs of such repair and placing in good condition to be charged against the lot, lots or tracts of land abutting such sidewalk and curb, or either, and to be a municipal lien as provided in the same manner as in an assessment for street improvement. Such assessment shall be declared by ordinance and shall be entered in the docket of city liens, and shall thereupon become a lien against the property – and the creation of such lien and the collection and apportionment of such lien shall be done and performed substantially in the same manner as in the case of the costs of street improvements, but irregularities or informalities in the procedure shall be disregarded.