ORS § 551.080
After the assessments have been made, the owner of any property assessed for such improvement in a sum not less than $50 may, at any time within 10 days after the cost of such diking district has been apportioned, file with the clerk of the county court a written application to pay the assessment in installments. The application shall state that the applicant waives all irregularities or defects, jurisdictional or otherwise, in the proceedings to create the diking district, and in the assessment and apportionment of costs. The application shall contain a provision that the applicant agrees to pay the assessment in five annual installments with interest at the rate of six percent per annum. But no such application shall be received and accepted where the assessment exceeds the assessed valuation of the property on the tax roll of the county. The installments shall be paid annually from the time of the apportionment of the costs. In case of default in the payment of any installment for 20 days after it becomes payable, the whole of the remaining unpaid sum shall be collected as a tax against the property assessed for the same.
ORS 551.080