These slope failures vary from a few rocks falling on to the highway, which work crews can remove in minutes, to a major landslide, that may require months of work and millions of dollars to correct. Typical effects include damage or destruction of portions of roads and railroads, sewer and water lines, homes and public buildings. Disruption of shipping and travel routes result in losses to commerce. Conclusions Landslides are often a secondary hazard related to other natural disasters. Landslide triggering rainstorms often produce damaging floods.
Earthquakes often induce landslides that can cause additional damage.
The identification of areas susceptible to landsliding is necessary to support grading, building, foundation design, housing density, and other land development regulations in reducing the risk of property damage and personal injury. The most significant effect of landslides is the disruption of transportation and the destruction of private and public property. Some work has been done to prevent developments on top of or below slopes subject to sliding. Much more needs to be done to educate the public and to prevent development in vulnerable areas. The King County Department of Development and Environmental Services is responsible for enforcing building codes for unincorporated King County, while cities in King County are responsible for their own enforcement.