Seismic Hazard Areas

Seismic hazard areas are any area subject to:

  • Underlying deposits indicative of risk of liquefaction during a seismic event;
  • Areas subject to slope failure, including lateral spreading, during a seismic event;
  • Areas subject to surface faulting during a seismic event;
  • Areas that are at risk of mass wasting due to seismic forces.

All development within seismic hazard areas must comply with the adopted International Building Code or International Residential Code.

Map Sources

Liquefaction Susceptibility and Site Class Maps of Cowlitz County, Open File Report 2004-20, Washington State Department of Natural Resources