N.C. Gen. Stat. § 153A-188

Except as provided in this Article, no land within a county is exempt from special assessments except land belonging to the United States that is exempt under the provisions of federal statutes and, in the case of water or sewer projects, land within any floodway delineated by a local government pursuant to Chapter 143, Article 21, Part 6. In addition, in the case of water or sewer projects, land owned, leased, or controlled by a railroad company is exempt from assessments by a county to the same extent that it would be exempt from assessments by a city under G.S. 160A-222.