21-56.1605. CLASSIFICATION OF TOPOGRAPHIC SURVEYS

(a) General. Topographic surveys are defined as the measurement of lands for the purpose of plotting the accurate location of existing surface and subsurface objects, elevations, and contour lines. For the purpose of specifying minimum allowable surveying standards, three general classifications of topographic surveys are established. All plats (maps), unless clearly marked as "Preliminary Plat - Not for recordation, conveyances, or sales" will be sealed, signed and dated by the registrant.

(b) Urban and suburban topographic surveys. (Class A). Urban and suburban topographic surveys include lands which lie within or adjoining a town or city. For Class A topographic surveys in North Carolina, the vertical error in feet shall not exceed 0.10 times the square root of the number of miles run from the reference datum.

(c) Other topographic surveys (Class B). Other topographic surveys include all lands which are not covered by Class A as described in Paragraphs (a) and (b) of this Rule. For Class B topographic surveys in North Carolina, the vertical error in feet shall not exceed 0.20 times the square root of the number of miles run from the reference datum.

(d) Trigonometric topographic surveys (Class C). Trigonometric topographic surveys can be used for vertical control for aerial and topographic mapping. The vertical error in feet shall not exceed 0.3 times the square root of the number of miles run from the reference datum.