ORS § 223.410
Whenever all or part of any estimated or final assessment for local improvements was or is declared void or set aside for any reason or its enforcement refused by any court by reason of jurisdictional or other defects in procedure, whether directly or by virtue of any court decision or when the governing body is in doubt as to the validity of all or part of any estimated or final assessment by reason of such defects in procedure, the governing body may by ordinance or resolution make a new estimated or final assessment or reassessment with respect to all or part of the original estimated or final assessment upon the lots which have been benefited by all or part of the local improvement to the extent of their respective and proportionate shares of the full value of such benefit.
ORS 223.410