17.10.100 Geologically hazardous areas – Identification.
The following are classified as potentially geologically hazardous areas:
A. Geologically hazardous areas are those areas that are naturally susceptible to geologic events such as landslides, seismic activity and severe erosion. Areas susceptible to one or more of the following types of hazards shall be designated as geologically hazardous areas:
1. Landslide Hazard Areas. Areas with slopes steeper than 40 percent. Areas with slopes between 15 to 40 percent that are underlain by soils largely consisting of silt and clay. Areas with slopes steeper than 15 percent with zones of emergent water such as ground water seepage or springs. Areas of landslide deposits regardless of slope.
2. Erosion Hazard Areas. Erosion hazards areas are lands underlain by soils identified by the U.S. Department of Agriculture Natural Resources Conservation Service (NRCS) as having “severe” or “very severe” erosion hazards.
3. Seismic Hazard Areas. Seismic hazard areas are lands that are underlain by soft or loose saturated soils that are subject to liquefaction settlement or spreading during earthquake induced ground shaking.
B. Other areas which the city has reason to believe are geologically unstable due to factors such as landslide, seismic or erosion hazards. (Ord. 3193 § 2, 2016)