N.D. Cent. Code § 40-27-11
A special fund or special funds shall be created in accordance with this section for the payment of refunding special assessment warrants or bonds. Such special fund may be created as a single consolidated fund for warrants or bonds issued to refund special assessment warrants or bonds of more than one district, or a separate special fund may be created for warrants or bonds issued to refund special assessment warrants or bonds of each district. In either case, the refunded warrants or bonds shall not be canceled but shall be retained by the municipality as an asset of the fund from which the refunding warrants or bonds are payable. The special fund or funds from which the refunded warrants or bonds are payable shall be continued, and payments therefrom shall be made on the warrants or bonds drawn thereon, in the same manner as though none of such warrants or bonds had been refunded. All payments made on the principal and on the interest of refunded warrants or bonds shall be credited to the fund from which the appropriate refunding warrants or bonds are payable and shall be applied in payment of the principal and on the interest on the refunding warrants or bonds in the manner prescribed by the resolution authorizing the issuance of such refunding warrants or bonds. To the extent refunding warrants or bonds are issued to refund the principal or interest, or both, of warrants or bonds, due or to become due within one year, for which a deficiency exists or is likely to exist in the fund or funds against which such outstanding warrants or bonds are drawn due to nonpayment or anticipated nonpayment of special assessments, any payments of such delinquent special assessments and such amounts of accrued interest and penalty thereon as necessary shall be set aside for the payment or redemption of the refunding warrants or bonds issued to fund such delinquencies.
N.D.C.C. § 40-27-11