Aging Dams Present Hazards to Communities. Removal—Rather Than Repair—Often Provides a Cost-Effective Option.

Two new studies analyze the role of state dam safety regulations and policies that incentivize—or disincentivize—dam owners to remove aging dams. They find that a lack of funding and information for dam owners, in combination with many dams falling through the regulatory cracks, is often a barrier to removal.


Oct. 22, 2020

News Type

Press Release

There are millions of dams in rivers and streams across the United States, and many of them no longer serve their original purposes. In a new pair of reports, researchers at Resources for the Future examine the national extent of dam removal and how it may fit into the wider scope of dam regulation.

“In some parts of this country, more than three-fourths of the dams are more than 50 years old, which is usually considered the normal lifespan of a dam. If dams are aging or are in need of repair, they may be posing a significant risk to property and people—the failure of the 96-year-old Edenville Dam in Michigan earlier this year is case in point,” said RFF Senior Fellow and coauthor Margaret Walls.

“The scope of state dam safety regulations, as currently constructed, is limited, with many dams falling through the cracks. In addition, for dams that are regulated, enforcement mainly relies on voluntary compliance by dam owners and not financial penalties or legal action. Sometimes dam deficiencies languish for years as a result. Across the country, most state dam safety programs are woefully underfunded and understaffed. But we identified some states with practices in place that bring removal to the forefront more often,” Walls said. “We feel some of these practices could be adopted more widely. Our research shows that it is often more cost-effective to remove a dam entirely rather than repair it, especially if the dam no longer serves a useful purpose.”

The first report, Dams and Dam Removal in the United States, uses nationwide data to paint a picture of the size, age, purpose and ownership type of dams across the United States. The second report, Aligning Dam Removal and Dam Safety: Comparing Policies and Institutions Across States, analyzes case studies of specific state-level dam safety programs and what could be done to improve the effectiveness of such programs.

Top Findings

  • The scope of dam safety regulations, as currently constructed, is limited.
  • Small dams tend to be unregulated. However, even among regulated dams, enforcement is generally weak, with owners given many years to address problems and typically facing no financial penalties or legal actions.
  • The effectiveness of dam safety programs varies from state to state. With the exception of California, most state dam safety programs are underfunded and understaffed.
  • A handful of states provide grant funding for dam removals. Massachusetts has the best combination of funding, information provision, and support for dam owners to encourage removal of obsolete and deficient dams.
  • In the water-scarce western United States, many dams are used for irrigation, and the value of water rights held by agricultural landowners impedes dam removal.


  • State dam safety programs need increased funding, and regulations need to be more strongly enforced.
  • Dam safety program staff should provide more information about dam removal options to dam owners.
  • Staff should engage more with conservation and environmental agencies in order to view the impact of dams more holistically.
  • The federal government should provide infrastructure funding and leadership on climate risk assessments and mitigation tactics.

“Removal isn’t just a cost-effective option for many failing dams,” Walls said. “It’s also one that will improve public safety, water quality, and aquatic habitats across the United States.”

Read the two parallel reports, Dams and Dam Removal in the United States by RFF Senior Fellow Margaret Walls and Research Analyst Vincent Gonzales, and Aligning Dam Removal and Dam Safety: Comparing Policies and Institutions Across States, by Walls.

These reports are companion studies to four forthcoming RFF issue briefs on funding options for dam removal. These studies are expected to be released in November 2020.

Resources for the Future (RFF) is an independent, nonprofit research institution in Washington, DC. Its mission is to improve environmental, energy, and natural resource decisions through impartial economic research and policy engagement. RFF is committed to being the most widely trusted source of research insights and policy solutions leading to a healthy environment and a thriving economy.

Unless otherwise stated, the views expressed here are those of the individual authors and may differ from those of other RFF experts, its officers, or its directors. RFF does not take positions on specific legislative proposals.

For more information, please see our media resources page or contact Media Relations and Communications Specialist Annie McDarris.

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