An investigation by The Associated Press has found at least 1,680 dams across the U.S. that post potential risk to those living nearby. They loom over homes, businesses, highways or entire communities that could face life-threatening floods if the dams don’t hold.
Deaths from dam failures have declined since a series of catastrophic collapses in the 1970s prompted the federal and state governments to step up their safety efforts. Despite those efforts, about 1,000 dams have failed over the past four decades, killing 34 people, according to Stanford University’s National Performance of Dams Program.
On average, the nation’s dams are over a half-century old, having been built for flood control, irrigation, water supply, hydropower, recreation or industrial waste storage. Despite the original reasons for construction, these aging structures are now being relied upon to protect more and more people as housing developments spring up nearby.
Some of those dams are simply no longer adequate to handle the intense rainfall and flooding associated with what many consider a changing climate. A National Climate Assessment released by the White House last year noted the growing frequency and intensity of storms as the climate changes.
Earlier this year, the 92-year-old Spencer Dam in northern Nebraska gave way after an unusually intense snow and rainstorm. A nearby resident was warned to flee his home, but his home was washed away in a flood carrying chunks of ice the size of a car. The man’s body has never been found.
“There are thousands of people in this country that are living downstream from dams that are probably considered deficient given current safety standards, Mark Ogden, a former Ohio dam safety official who is now a technical specialist with the Association of State Dam Safety Officials, told The Associated Press.
The association estimates it would take more than $70 billion to repair and modernize the nation’s more than 90,000 dams. But with most dams privately owned, it’s difficult for regulators to require improvements from operators who are unable or unwilling to pay the steep costs involved.
“Most people have no clue about the vulnerabilities when they live downstream from these private dams,” said Craig Fugate, a former administrator at the Federal Emergency Management Agency. “When they fail, they don’t fail with warning. They just fail, and suddenly you can find yourself in a situation where you have a wall of water and debris racing toward your house with very little time, if any, to get out.”
Fugate told AP reporters that even if kept in good condition, thousands of dams could be at risk because of extreme rainstorms.
“These are like ticking bombs just sitting there, waiting for the wrong conditions to occur to cause catastrophic failure,” he said.
There is currently no national standard for inspecting dams, a fact that has led to a patchwork of state regulations. Some states inspect high-hazard dams — those where loss of human life is likely if the dam were to fail — annually while others wait for as long as five years between inspections. Some states never inspect low-hazard dams.
Given the growing frequency and intensity of storms and the potential loss of life associated with dam failures caused by those storms, Congress should begin working to develop national standards for dam inspections.