As an alternative method for the collection of assessments levied under this part, the council, after the adoption of the resolution ordering the improvement, may order the assessment roll prepared by the city forester, showing the amount of the assessment against each lot or parcel of land, to be turned over to the assessor and the tax collector of the city, whereupon it shall be the duty of said officers to add the amount of said assessments to the next regular bill for taxes levied against the said lot or parcel of land for city purposes. Where city taxes are collected by the county officials, said assessment roll shall be delivered to the county auditor, who shall enter the amount thereof on the county assessment book opposite the description of the lot or parcel of land, and the amount shall be collected together with all other taxes thereon against the lot or parcel of land; provided, that said assessment roll shall be delivered to the county auditor before the date fixed by law for the delivery of the assessment books to the county board of equalization. Thereafter said amount shall be collected at the same time and in the same manner as city taxes are collected and shall be subject to the same penalties and interest and to the same procedure under foreclosure and sale, in case of delinquency, as provided for city taxes. All laws applicable to the levy, collection and enforcement of city taxes are hereby made applicable to such special assessment taxes.