N.C. Gen. Stat. § 156-95
If the total cost of the improvement is less than an average of twenty-five cents (25¢) per acre on all the land in the district, the board of drainage commissioners shall forthwith assess the lands in the district therefor, in accordance with their classification, and said assessment shall be collected in one installment, by the same officer and in the same manner as State and county taxes are collected, and payable at the same time. In case the total cost exceeds an average of twenty-five cents (25¢) per acre on all lands in the district, the board of drainage commissioners shall give notice for three weeks by publication in some newspaper published in a county in which the district, or some part thereof, is situated, if there be any such newspaper, and also by posting a written or printed notice at the door of the courthouse and at five conspicuous places in the district, reciting that they propose to issue bonds for the payment of the total cost of the improvement, giving the amount of bonds to be issued, the rate of interest that they are to bear, and the time when payable. Any landowner in the district not wanting to pay interest on the bonds may, within 15 days after the publication of such notice, pay to the county treasurer the full amount for which his land is liable, to be ascertained from the classification sheet and the certificate of the board showing the total cost of the improvement, and have his lands released from liability to be assessed for the improvement; but such land shall continue liable for any future assessment for maintenance or for any increased assessment authorized under the law.
N.C. Gen. Stat. § 156-95