Dam Removal: Issues, Considerations, and Controversies

Publication Date: June 2006

Publisher: Library of Congress. Congressional Research Service

Author(s):

Research Area: Environment

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Abstract:

River management is complex, and in many cases decisions must be made to balance conflicting values. Dams are built because they provide numerous benefits to society, including flood control, navigation, irrigation and drinking water, hydropower, and recreation. But they are not without their detriments: dams also block fish passage, alter natural river systems, modify sediment and water temperature regimes, and inundate sites of cultural importance. Every dam is built with an expected life span and will eventually need to be repaired, replaced, or removed.

While dams may once have been viewed as almost entirely beneficial, today they are seen as having both positive and negative attributes. In this light, policymakers and the public have come to view dam removal as one option in the effort to balance the costs and benefits of river management. The federal government has legislated dam removal through the Elwha River Ecosystem and Fisheries Restoration Act (P.L. 102-495), and the President's FY2007 budget requests funding for a dam removal program -- the National Marine Fisheries Service Open Rivers Initiative has an FY2007 budget request of $6 million. Congress had also made clear its intent to ensure funding oversight in dam removal issues. As an example, P.L. 106-60, Section 316, limited the authority of the Bonneville Power Administration in its cost recovery, to ensure that the agency did not generate surplus revenue to be put toward Snake River dam removal.

The benefits and detriments of a dam are case-specific, and stakeholders' evaluation of whether dam removal is an attractive option depends on the values that they assign to those qualities. Some federal dams -- notably, four projects on the Lower Snake River in Washington -- have generated contentious debate, litigation, and specific legislation (cited above). In recent years, dam removal has become a more commonly considered choice among the available options for managing the public's investment in our national inventory of dams. In many cases -- there have been some 500 documented dam removals in the United States -- removal may provide greater economic, environmental, public safety, aesthetic, and recreational benefits than dam maintenance, modification, and upkeep, particularly for aging and smaller dams. But there are other circumstances when dam removal may not be the appropriate choice, when removal would cause socially unacceptable effects, such as the loss of flood protection for critical areas, the destruction of wetlands created by the dam, or the loss of energy from a hydropower project.

As America's dams age, their owners, regulatory agencies, and the public must decide how to manage these structures. Although decisions regarding dams are unique to each location and highly reflective of local interests, Congress has been, and will likely continue to be, asked to fund dam removal programs and to become involved in specific dam removal issues. Considerations leading up to dam removal, and issues related to dam removal itself, are the focus of this report. It will be updated as appropriate.