Assessments may be made on the basis of:
Whenever the basis selected for assessment is either area or value added, the council may provide for the laying out of benefit zones according to the distance of benefited property from the project being undertaken, and may establish differing rates of assessment to apply uniformly throughout each benefit zone.
For each project, the council shall endeavor to establish an assessment method from among the bases set out in this section which will most accurately assess each lot or parcel of land according to the benefit conferred upon it by the project. The council's decision as to the method of assessment shall be final and conclusive and not subject to further review or challenge.
N.C. Gen. Stat. § 160A-218