N.D. Cent. Code § 40-24-06: Paving and repaving special assessments extended over a period of not more than thirty years

Special assessments for the payment of the cost of paving or repaving shall be payable in equal annual amounts, or in such annual amounts as will permit the annual increase in payment of principal to approximate the annual decrease in the interest on amounts remaining unpaid, extending over a period of not more than thirty years.