ORS § 224.160
Pending the making of an assessment for all or part of any construction referred to in ORS 224.140, the city may make temporary loans or advances from the fund legally available under its charter in order to procure the federal aid or perform such construction, or both. Such loan shall be refunded from a local assessment when made and collected. If the city is without adequate funds to make such temporary loan it may from time to time borrow funds therefor and give its certificate of indebtedness for the money so borrowed. This certificate shall be paid only from funds collected from the local assessment authorized to be made for the construction. The rate of interest upon the certificates of indebtedness shall not exceed six percent per annum and no greater amount shall be borrowed than the amounts necessary for the purposes of construction.
ORS 224.160