ORS § 548.120
In all cases where the board of directors of any irrigation district or the board of supervisors of any drainage district has instituted proceedings for the purpose of having an adjudication of the court as to the regularity and legality of the proceedings in connection with any of the matters specified in ORS 548.105, and where notice has been published directed to the parties specified by ORS 548.110, for the length of time specified by that section, and the full time provided by that section has elapsed after publication before any judgment has been entered therein, all such judgments so rendered by the courts hereby are validated and declared to be effective and sufficient for all purposes, notwithstanding any other defects in the proceedings and notice upon which such judgments are based.
ORS 548.120