Oregon Revised Statutes Revenue and Taxation § 311.255

(1) All ad valorem property taxes, taxes on property that are imposed upon property subject to ad valorem taxation and all special assessments, fees or other charges required by law to be placed upon the tax roll, which have been lawfully levied or imposed and certified to the assessor by any taxing district authorized by law to levy or impose such taxes, assessments, fees or charges, shall be collected by the tax collector, only in the same manner and at the same time as taxes for county purposes are collected.

(2) No taxing district may separately charge or collect any tax on property that is imposed upon property subject to ad valorem taxation certified under ORS 310.060, in advance or otherwise.

(3) Charges of a water improvement company organized under ORS 554.005 to 554.340 shall be collected in the same manner as taxes under subsection (1) of this section if the charges are certified to the assessor by the company board of directors under ORS 554.130.