Thousands of people live downstream from the dams, but are not always aware of the risks.
As the climate changes, heavy rains and violent storms have exposed communities to greater flood hazards and endangered the country’s aging economy. dams are at greater risk of failure. This became clear recently when storm flooding damaged or breached dams in Georgia, MinnesotaNew York, South Carolina, Texas and Wisconsinwhich led to evacuations and costly repairs.
An Associated Press investigation found that conflicting federal policies could hamper local officials’ ability to share details with residents, businesses and other homeowners about where flooding could occur if a dam fails. That same information gap could also cost residents more for flood insurance.
The problem has existed for years, even though federal officials have been warned of its consequences.
Here are some pick up points from the AP report about the conflicting federal policies regarding possible dam breaks.
The Federal Emergency Management Agency oversees a flood insurance program available to communities that adopt and enforce floodplain management regulations. Nearly 22,700 local governments participate in the National Flood Insurance Program. As of late July, it offered $1.3 trillion in insurance coverage to about 4.7 million policyholders — approximately 1 million policies decreased since peak participation in the program in 2009.
FEMA also oversees a voluntary program that offers discounts on flood insurance. The Community Rating System rates a community’s flood mitigation and safety measures on a scale of 1 to 10, with Class 1 being the best.
A Class 1 rating entitles residents of a community to a top 45% discount on their flood insurance premiums. But that’s not easy to achieve. Only two of the 1,500 local governments that participate in the Community Rating System have earned the highest discount for their residents.
One of the areas assessed by the Community Rating System focuses on dams. To earn a top ranking, communities must maintain maps of the homes, businesses and critical facilities that could be inundated with floodwaters if a dam were to fail, and educate the public about the potential risks. Only four communities nationwide have received any recognition for their local efforts regarding potential dam failures.
One reason so few communities qualify for the biggest flood insurance discounts is that some federal agencies have prohibited the release of flood maps for dams they own or operate.
After the terrorist attacks of September 11, 2001, some federal agencies cited national security concerns in refusing to release certain information about dams. They feared that dams could become targets if terrorists knew they could cause devastating floods.
The Bureau of Reclamation owns 430 dams in the western U.S., including some of the nation’s largest structures. But it has required confidentiality agreements when sharing dam flood maps and emergency action plans with local officials. That has prevented officials from sharing specific information about the risks of dam failures with residents who could be flooded.
The Federal Energy Regulatory Commission, which regulates about 1,800 electricity-producing dams, categorizes dam inundation maps as critical infrastructure information that “could be useful to someone planning an attack” and requires those who receive such information to sign a confidentiality agreement. But FERC cannot prevent a dam owner from independently sharing the information.
Documents obtained by the AP show that a California emergency services official raised concerns about the policy during a January 2020 meeting of FEMA’s National Dam Safety Review Board.
The federal “procedures for sharing information about dams are costing communities points, homeowners money and potentially citizens’ lives,” he said, according to meeting minutes released to the AP this summer, nearly two and a half years after the news organization filed a Freedom of Information Act request with FEMA.
In response to questions from the AP, the Bureau of Reclamation said it is reviewing its policy and will allow communities to publicly share information about dam flood zones, including potential surge travel times, flood depths and durations. The agency said the changes will begin in 2025, but that it could take more than eight years to complete all the dams.
Since the 2020 meeting, the U.S. Army Corps of Engineers has also become more transparent about the flood risks of its dams. The Corps began posting dam flood maps online in late 2021 after determining that releasing the information “is more beneficial to the public than any risk of misuse.”
FEMA is considering possible changes to the Community Rating System for flood insurance. The agency sought public input in 2021 on ways to revamp the system to better incentivize communities to reduce flood risk. Several commenters pointed to challenges in obtaining credit for dam safety initiatives, including the reluctance of some federal agencies to share information about flood zones from dam failures.
Nothing immediate came of that assessment. This summer, FEMA reopened a period for public comment about possible changes to the Community Rating System. People can submit suggestions until September 9. But FEMA does not expect to implement changes until 2026.