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.
