S.D. Codified Laws § 46A-11-13

Any owner of any tract of land against which an assessment for drainage is made who, within thirty days after the making of the assessment, files with the county auditor an agreement in writing that he will pay the assessment with interest as fixed by the board shall be allowed to pay the assessment in ten annual installments with interest payable annually. Assessment certificates may not issue until after expiration of the period for filing such agreements and, if issued as payable in installments, may be issued in coupon form.