2,500 ‘high-risk’ U.S. dams are sinking into the ground
Dams across the United States are in dire need of repair, and critical infrastructure may be in even worse shape than engineers predicted. According to geoscientists, more than 2,500 of the country’s more than 16,700 structures are classified as having high risk potential and in “poor condition.” This classification means that dams could cause significant death and destruction if compromised. Additionally, radar analysis indicates that many of these facilities could further deteriorate out of sight of inspection teams.
The United States is home to more than 92,000 dams dedicated to hydroelectric power, clean water, and environmental protection for surrounding communities. However, the majority of these projects are not new or updated. Most active dams were built in the 1950s and 1960s, and the average age of a facility is 61 years. Today, it is estimated that seven out of ten dams in the country are at least 50 years old. Despite their critical nature, maintenance and monitoring remain largely underfunded. Although the Association for State Dam Safety Officials estimates that more than $165 billion is needed for repairs, federal funding currently allocates a fraction of that amount for maintenance.
“Without a more meaningful commitment to dam safety…the cost necessary to return the nation’s dams to good condition will continue to rise and downstream communities will face greater risk of harm from potential dam failures,” the American Society of Civil Engineers concluded in its 2025 annual assessment.
Unfortunately, this risk is probably more serious than expected. Mohammad Khorrami, a geoscientist at Virginia Tech, recently assembled a team to conduct a national analysis of the structural integrity of dams without having to leave their campus. Using a satellite tool called interferometric synthetic aperture radar, Khorrami and his colleagues examined the extent to which many high-risk dams have sunk into the earth over the past decade. They have particularly focused on hydroelectric structures because of both their downstream communities and the amount of infrastructure that depends on them. The results stunned them. In many cases, dams thought to have already stabilized continued to leak.
“I want to emphasize that this is a preliminary result. We need to do more in-depth analysis to have a concrete answer,” explained Virginia Tech geoscientist Manoochehr Shirzaei. “But some observations may suggest that some of this infrastructure is experiencing internal degradation.”
It’s been decades since the United States experienced a catastrophic dam failure, but Khorrami warns that such an event today would be “a disaster.” They cited the Roanoke Rapids Dam in North Carolina as an example. The findings by Khorrami and his team confirmed previous inspections of the site: the north face of the dam is slowly sinking. Without vital repairs, the structural concrete could eventually crack and threaten the nearby town of more than 15,000 residents. But the consequences of such a disaster go beyond neighboring communities.
“Some dams actually serve as a sub-buffer for water used for agriculture and power generation,” Shirzaei explained. “These dams can create a ripple effect if they fail, which can impact the national economy. »
The researchers insisted there are still ways to mitigate the worst outcomes. Citing a companion article published earlier this year, Khorrami explained that much of the compromise of dams is due to poor local management and maintenance.
“Nearly 40 to 50 percent [of risk] It’s something that’s in our hands,” he said. “It’s difficult to tackle all these roadblocks. If you cannot financially take care of everyone at once, we can provide priority roadblocks.
PopSci Outdoor Gift Guide 2025
