N.C. Gen. Stat. § 156-124: No drainage assessments for original object may be levied on property when once paid in full.

Whenever any assessment has been made or may be made by any drainage district formed under the laws of the State of North Carolina upon any lands in said district, either for construction or maintenance of its system of drainage or for any other purpose, and the particular assessment made against any particular piece of property has been paid or shall be hereafter paid in full, then and in that event no other or further assessment may be made upon said land for the purpose of providing money for the purpose for which the original assessment was made. (1933, c. 504; 1935, c. 469, s. 5.)