For the purposes of this section, topographic elements consist of information shown on a map which depicts the horizontal and vertical positions of natural and/or fabricated features and existing terrain surfaces. Usually, contour lines and spot elevations are used to depict surface relief, but a variety of methods can be used to show changes in terrain.

The following requirements shall apply to maps that include topographic elements, prepared by professionals registered under chapters 18.43 and 18.210 RCW. Such requirements should be considered minimum only. The professional conducting the work will determine what precision and accuracy are expected to be utilized for topographic mapping services necessitating various levels of accuracy.

(1) The following elements must be included on every map that includes topographic elements:

(a) Vertical datum used (such as "assumed," "NAVD 88," "NSRS," "unknown");

(b) North arrow;

(c) Map scale and graphic scale bar;

(d) Legend of symbols used;

(e) Licensee name and contact information;

(f) Seal and signature of licensee.

(2) Statements of clarification for elements shown:

(a) Basis of elevations citing benchmark(s) used with elevation(s) (such as "city bench mark 20-01, elevation 456.32 feet, GPS observation including metadata");

(b) Purpose or intended use of the topographic elements shown on the map (such as "preliminary plat," "on-site septic design," "civil engineering design");

(c) A description of the source of the contours (such as "contours derived from direct field observations," or "contours shown are from county GIS");

(d) Labeling to determine contour interval(s);

(e) Description of project benchmarks established (such as "railroad spike in power pole," "chiseled 'X' in concrete curb");

(f) Statement of elevations and contour accuracy (such as "national mapping standards, one-half the contour interval");

(g) Statement on limitation of use (such as "preliminary-not for design," "this is not a boundary survey");

(h) Source of boundary information (such as "record of survey including auditor indexing information," "county GIS") and method(s) used to relate area mapped to said boundaries.

(3) Statements of clarification of utility information shown:

(a) Source of utility location (such as "surface markings," "as-built," "potholing," or "field measurement");

(b) Statement of accuracy of utility depiction (such as "locations of underground utilities shown hereon are based upon field measurement" or "locations of underground utilities shown hereon are based upon as-built maps");

(c) A statement of the scope of work between the project owner and the licensee regarding the comprehensiveness, exclusions, and limits of the utility investigations leading to these utility depictions.