When a political subdivision issues a certificate of indebtedness under this chapter, the political subdivision, by resolution authorizing the issuance of the certificate of indebtedness, shall establish a sinking fund for the retirement of the certificate of indebtedness, including interest, on its due date. The resolution must also provide for the regular accumulation of money in the sinking fund from the revenues pledged to the payment of the certificate of indebtedness. Upon the accumulation of sufficient money in the sinking fund to pay the principal and interest which will be due and owing on the maturity date of the certificate of indebtedness, no additional revenues may be credited to the sinking fund.
N.D.C.C. § 21-02-07