Hydrologic Monitoring of Landslide-Prone Coastal Bluffs near Edmonds and Everett, Washington, 2001?2004

In 2001, a cooperative monitoring effort between the U.S. Geological Survey (USGS), the Burlington Northern Santa Fe Railway (BNSF), BNSF's geotechnical consultant, Shannon and Wilson, Inc., and the Washington Department of Transportation was begun to determine whether near-real-time monitoring of rainfall and shallow subsurface hydrologic conditions could be used to anticipate landslide activity on the bluffs. Monitoring currently occurs at two sites-one near Edmonds, Washington, and the other near Everett, Washington. During initial planning, the USGS proposed to evaluate the monitoring results at the end of 3 years. This report summarizes site conditions, methods, system reliability, data, and scientific results, and identifies possible future directions for development of monitoring and early warning of impending landslide activity. [Summary provided by the USGS.]