SEATTLE — People living in the path of a deadly Washington state landslide had virtually no warning before a wall of mud, trees and other debris thundered down the mountain. Some of the homeowners didn’t even know the hillside could give way at any time.
Unlike the warning systems and elaborate maps that help residents and officials prepare for natural disasters such as floods and hurricanes, there’s no national system to monitor slide activity and no effort underway to produce detailed nationwide landslide hazard maps.
The U.S. Geological Survey doesn’t track or inventory slide areas on a national scale, despite an ambitious plan to do so more than a decade ago when Congress directed it to come up with a national strategy to reduce landslide losses.
That’s left states and communities to put together a patchwork of maps showing landslide hazards. In some cases, they are discovering that more buildings than previously thought are sitting on unstable ground. Even then, that information may not make its way to property owners.