Oregon Revised Statutes Mineral Resources § 523.330

Upon the completion of the improvement project, if it is found that the assessment previously levied upon any property is more than sufficient to pay the costs of the improvements, the district board shall ascertain and declare the amount of the excess by ordinance. When declared, the excess amounts shall be entered on the lien docket as a credit upon the appropriate assessment. If any assessment has been paid, the person who paid it, or the legal representative of the person, shall be entitled to the repayment of the rebate credit, or the portion thereof which exceeds the amount unpaid on the original assessment.