Oregon Revised Statutes Cities § 223.866

(1) The city each year shall estimate assessments needed and the amount of assessment for each tax account, and the amount thereof may be levied and returned to the officer whose duty it is to extend the ad valorem tax roll at the time required by law for taxes to be levied and returned.

(2) All assessments levied by the city shall become payable at the same time, may be collected by the same officer who collects ad valorem taxes and shall be turned over to the city according to law.

(3) The officer whose duty it is to extend the city levy may extend the levy of the city in the same manner as city taxes are extended.

(4) Property shall be subject to sale for the nonpayment of assessments levied by the city in like manner and with like effect as in the case of city taxes.