Aging US dams pose risk to thousands
Reservoir No. 1, a 180 million-gallon water supply that has been out of service much of the past few decades, sits against the backdrop of the city skyline, Oct. 15, 2019, in Atlanta. The city made repairs and brought it back online in 2017, only to shut it down again after water leaks were noticed near businesses located beneath the dam. Were the dam to catastrophically fail, the water could inundate more than 1,000 single-family homes, dozens of businesses, a railroad and a portion of Interstate 75, according to an emergency action plan.
(AP Photo/David Goldman)
On a cold morning last March, Kenny Angel got a frantic knock on his door. Two workers from a utility company in northern Nebraska had come with a stark warning: Get out of your house.
Just a little over a quarter-mile upstream, the 92-year-old Spencer Dam was straining to contain the swollen, ice-covered Niobrara River after an unusually intense snow and rainstorm. The workers had tried but failed to force open the dam’s frozen wooden spillway gates. So, fearing the worst, they fled in their truck, stopping to warn Angel before driving away without him.
Minutes later, the dam came crashing down, unleashing a wave of water carrying ice chunks the size of cars. Angel’s home was wiped away; his body was never found.
“He had about a 5-minute notice, with no prior warning the day before,” Scott Angel, one of Kenny’s brothers, said.
State inspectors had given the dam a “fair” rating less than a year earlier. Until it failed, it looked little different from thousands of others across the U.S.—and that could portend a problem.
A more than two-year investigation by The Associated Press has found scores of dams nationwide in even worse condition, and in equally dangerous locations. They loom over homes, businesses, highways or entire communities that could face life-threatening floods if the dams don’t hold.
A review of federal data and reports obtained under state open records laws identified 1,688 high-hazard dams rated in poor or unsatisfactory condition as of last year in 44 states and Puerto Rico. The actual number is almost certainly higher: Some states declined to provide condition ratings for their dams, claiming exemptions to public record requests. Others simply haven’t rated all their dams due to lack of funding, staffing or authority to do so.
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. Yet about 1,000 dams have failed over the past four decades, killing 34 people, according to Stanford University’s National Performance of Dams Program.
Built for flood control, irrigation, water supply, hydropower, recreation or industrial waste storage, the nation’s dams are over a half-century old on average. Some are no longer adequate to handle the intense rainfall and floods of a changing climate. Yet they are being relied upon to protect more and more people as housing developments spring up nearby.
“There are thousands of people in this country that are living downstream from dams that are probably considered deficient given current safety standards,” said Mark Ogden, a former Ohio dam safety official who is now a technical specialist with the Association of State Dam Safety Officials.
The association estimates it would take more than $70 billion to repair and modernize the nation’s more than 90,000 dams. But unlike much other infrastructure, most U.S. dams are privately owned. That makes it difficult for regulators to require improvements from operators who are unable or unwilling to pay the steep costs.
“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.”
It’s unclear whether Angel, a 71-year-old Vietnam War veteran, declined to flee or simply ran out of time after workers with the Nebraska Public Power District warned him that water was overtopping the dam near Spencer, a town of fewer than 500 residents.
An attorney for Angel’s wife, who wasn’t home when the dam broke, has filed a $5 million lawsuit alleging negligence. It claims the power utility failed to properly maintain the dam, train its employees or inform the Angels of dangerous conditions.
Even though the Angels’ home was squarely in its path, the dam was rated as a “significant” rather than “high” hazard, meaning it wasn’t required under Nebraska law to have a formal emergency action plan. About 20% of state-regulated high-hazard dams nationwide still lack emergency plans, according to the U.S. Army Corps of Engineers, which maintains the national dam inventory.
When last inspected in April 2018 , Spencer Dam’s “fair” rating was accompanied by an ominous notation: “Deficiencies exist which could lead to dam failure during rare, extreme storm events.”
Tim Gokie, chief engineer of Nebraska’s dam safety program, said the warning was due to past water seepage the power utility addressed by installing a drain system. Ultimately, Gokie said, the rising Niobrara River simply overwhelmed the concrete and earthen dam, which was built in 1927 to generate hydroelectricity, not for flood control.
“The fact was that it was just an unprecedented situation,” Nebraska Public Power District spokesman Mark Becker said. “It was beyond what everybody anticipated.”
Nebraska was among the states hardest hit by storms and floods this year that have caused an estimated $1.5 billion in damage to roads, dams, utilities and other infrastructure in 28 states, according to an AP analysis.
A National Climate Assessment released by the White House last year noted growing frequency and intensity of storms as the climate changes. That can push some dams beyond what they were designed to handle.
Even if kept in good condition, thousands of dams could be at risk because of extreme rainstorms, said Fugate, the former FEMA official.
“These are like ticking bombs just sitting there, waiting for the wrong conditions to occur to cause catastrophic failure,” he said.
The nation’s dams are categorized as high, significant or low hazard in the National Inventory of Dams database. High hazard means loss of human life is likely if a dam were to fail. A significant rating means no deaths are likely, although economic and environmental damage are possible.
There is no national standard for inspecting dams, leading to a patchwork of state regulations. Some states inspect high-hazard dams every year while others wait up to five years. Some states never inspect low-hazard dams—though even farm ponds can eventually pose a high hazard as housing developments encroach.
Dam conditions are supposed to be rated as unsatisfactory, poor, fair or satisfactory. But the ratings are subjective—varying by state and the interpretations of individual inspectors—and are not always publicly disclosed.
Since the Sept. 11, 2001, terror attacks, the U.S. government has cited national security grounds in refusing to include dams’ conditions in its inventory, which was updated most recently in 2018. But the AP was able to determine both condition and hazard ratings for more than 25,000 dams across the country through public records requests.
The tally includes some of the nation’s most well-known dams, such as Hoover Dam along the Colorado River, but mostly involves privately owned dams. Many are used for recreation.
The AP then examined inspection reports for hundreds of high-hazard dams in poor or unsatisfactory condition. Those reports cited a variety of problems: leaks that can indicate a dam is failing internally; unrepaired erosion from past instances of overtopping; holes from burrowing animals; tree growth that can destabilize earthen dams; and spillways too small to handle a large flood. Some dams were so overgrown with vegetation that they couldn’t be fully inspected.