Landslides, including rockfalls, debris flows, and a variety of other slope movements cause billions of dollars in property losses in the United States, and between 25 and 50 deaths annually, according to USGS scientists. All 50 states have landslide problems to some extent. While this perception is partly true, many of the most significant landslides are produced by powerful geologic systems operating on much larger scales. In addition to landslides and debris flows that occur following heavy rainfall, landslides can be triggered by earthquakes, volcanic eruptions, coastal and river bank erosion, or the buildup of underground water pressures by an accumulation of seasonal rainfall. The following guidelines reflect what areas are generally prone to landsliding and what residents of these areas should do before and after intense storms.
Additional information is provided for residents who live near steep, sloping hills.
If a very detailed site analysis is desired, contract with a private consulting company that specializes in earth movement. Such companies would likely be those specializing in geotechnical engineering, structural engineering, or civil engineering. Your local, state or county geologist can usually advise you as to the best kind of professional to contact. Become familiar with the land around you. Learn whether debris flows have occurred in your area by contacting local officials, state geological surveys or departments of natural resources, and university departments of geology.