One lesson from the September 11, 2001, attacks on the World Trade Center and the Pentagon is that infrastructure built for beneficial purposes can become an instrument of mass destruction if it fails as the result of a malicious act. Dams and their related infrastructure are primarily built to control the flow of a river and mitigate flooding. The water impounded behind a dam can be used to generate power and to provide water for drinking, irrigation, commerce, industry, and recreation. However, if a dam fails, the water that would be unleashed has the energy and power to cause mass destruction downstream, killing and injuring people and destroying property, agriculture, industry, and local and regional economies.

The U.S. Bureau of Reclamation is responsible for managing and operating some of this nation’s largest and most critical dams, including five national critical infrastructure (NCI) facilities: the Hoover, Grand Coulee, Folsom, Shasta, and Glen Canyon dams. Reclamation’s total inventory includes 249 facilities comprising 479 dams and dikes and related facilities. The importance of the water and power supplies provided by these facilities to the quality of life in 17 western states cannot be overstated. The failure of one or more of these dams as the result of a malicious act would come with little warning and time for evacuation. In the worst case, where a large dam is located above a major population center, the devastation in terms of lost lives and destruction of property, power and water supply facilities, and commerce could rival or exceed that in New Orleans after the levees failed following Hurricane Katrina.

At the request of the U.S. Bureau of Reclamation, the National Research Council, through the Board on Infrastructure and the Constructed Environment, appointed a multidisciplinary committee of 14 experts to assess Reclamation’s security program and determine its level of preparedness to deter, respond to, and recover from malicious acts to its physical infrastructure and to the people who use and manage it. This document summarizes the work and findings of the committee.