The city auditor shall pay special improvement warrants and the interest coupons appurtenant thereto as they mature and are presented for payment out of the district funds on which they are drawn respectively and shall cancel the warrants when paid, except that definitive improvement warrants, when refunded pursuant to the provisions of sections 40-27-06 to 40-27-12, shall not be canceled but shall be retained by the municipality, in trust for the holders of the refunding improvement warrants or bonds issued thereunder, as therein provided. Definitive warrants shall be issued in lieu of temporary warrants at or before the time when any such warrants are to be so refunded.
40-24-23. Matured improvement warrants or interest coupons may be used to pay special assessments. Any matured special improvement warrant or interest coupon may be used in the payment of special assessments levied for the payment of the improvement for which the warrant or interest coupons were issued. The warrants or coupons so used shall be canceled and retired by the city auditor.