Chapter 17.13
SEISMIC HAZARD AREAS
Sections:
17.13.030 Geotechnical report.
17.13.040 Geotechnical report – Contents.
17.13.050 Geotechnical assessments.
17.13.010 General.
Seismic hazard areas are areas subject to severe risk of damage as a result of earthquake induced ground shaking, slope failure, settlement, soil liquefaction, lateral spreading, or surface faulting. (Ord. 1566-05 § 33, 2005; Ord. 1114 § 2, 1992).
17.13.020 Classification.
The following criteria shall be used in determining seismic hazard areas:
A. Areas identified on Washington State Department of Natural Resources seismic hazard maps for Western Washington; or
B. Areas having a slope greater than 30 percent; or
C. Areas of poorly compacted artificial fill. (Ord. 2018 § 2, 2019; Ord. 1566-05 § 34, 2005; Ord. 1114 § 3, 1992).
17.13.030 Geotechnical report.
For all regulated activities proposed within designated seismic hazard areas or within 200 feet of such areas, a critical areas report as required by FMC 17.05.085 and a geotechnical report prepared by a geologist or geotechnical engineer licensed as a civil engineer in the state of Washington shall be submitted. If an applicant can demonstrate through submittal of a geotechnical assessment that no seismic hazards exist on-site, the requirement for a geotechnical report may be waived by the community development director. (Ord. 1566-05 § 35, 2005; Ord. 1114 § 4, 1992).
17.13.040 Geotechnical report – Contents.
The geotechnical report shall include at a minimum the following:
A. A discussion of subsurface conditions;
B. A complete discussion of the potential impacts of seismic activity on the site;
C. A site plan of the area delineating all areas of the property subject to seismic hazards;
D. A discussion of mitigating measures which can be taken to eliminate seismic risks;
E. A site map showing all known and mapped faults within 200 feet of the project area or that have the potential to be affected by the proposal; and
F. An evaluation of the effectiveness of the proposed mitigation measures. (Ord. 1566-05 § 36, 2005; Ord. 1114 § 5, 1992).
17.13.050 Geotechnical assessments.
A. Should the applicant question the presence of seismic hazard areas on the site, the applicant may submit a geotechnical assessment prepared by a geologist or geotechnical engineer licensed as a professional civil engineer in the state of Washington.
B. The geotechnical assessment shall include at a minimum the following:
1. A discussion of the surface and subsurface geologic conditions of the site;
2. A site plan of the area delineating all areas of the site subject to seismic hazards based on mapping and criteria referenced in FMC 17.13.020.
3. A contour map of the proposed site, at a scale of one inch equals 200 feet, clearly delineating slopes for ranges between 15 and 29 percent and 30 percent and greater, and including figures for area coverage of each slope category on the site.
C. If the geotechnical assessment demonstrates, to the satisfaction of the community development director, that the proposed site is not located in any seismic hazard areas, then the requirements of this chapter shall not apply. (Ord. 1114 § 6, 1992).
17.13.060 Location of critical facilities.
Repealed by Ord. 2018. (Ord. 1114 § 7, 1992).