Current through Register Vol. 24-18, September 15, 2024
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.
