Aging dams put thousands at risk; structures not designed for current climate patterns

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A team of experts surveys damage to the Luckasson Dam in Monroe County after torrential rains caused the earthen structure to fail on Aug. 28, 2018.

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 five-minute notice, with no prior warning the day before,” said Scott Angel, one of Kenny’s brothers.

Dams Legacy of Neglect

A dam near Spencer, Neb., in 2013, top, when it was holding back water on the Niobrara River and again in March 2019, after it failed during a flood. State inspectors had given the dam a “fair” rating less than a year earlier.

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.

Wisconsin has only six dams considered a risk to human safety that are in poor condition, according to data compiled by The Associated Press. Even so, eight dams in the state were washed out by record-setting rainfalls last year.

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.”


The Jersey Valley dam was one of two Vernon County dams that failed during heavy rains on Aug. 28, 2018. Water overflowed the spillway and cut a 54-foot section from the 50-year-old earthen structure, which had received millions of dollars in repairs after flooding in 2008.

Historic rainfalls

Fourteen Wisconsin dams have failed since 2008, according to DNR data. Those include the eight that were washed out last year and a ninth that failed after it was damaged by muskrats.

Three failed in Douglas County when up to 15 inches of rain fell on northern Wisconsin over several days in mid-June. Then in August, another series of storms dumped more than a foot of rain in just two days on the hilly terrain of Monroe and Vernon counties, causing five earthen dams to burst.

Firefighters and other first responders rescued about 350 people downstream from the dams in the early morning hours of Aug. 28, said Brandon Larson, emergency management director for Vernon County.

“It’s almost like a giant bulldozer coming down the valley floor,” said Bob Micheel, director of Monroe County’s land conservation department. “It’s a wall of water. We were very lucky that nobody was injured.”

Despite the lack of human casualties, the failures underscore the challenges that increasingly intense rain events present for structures designed for the risks of the past century.

Luckasson dam

Floodwaters breached the 40-foot-tall Luckasson dam on Aug. 28, 2018, sweeping about 28,000 cubic yards of rock and soil downstream. The dam, completed in 1963, was designed to control flooding in the Coon Creek watershed.

All eight dams were in fair or satisfactory condition, according to the DNR.

“They all failed during extreme rain events,” said Tanya Lourigan, state dam safety engineer for the Wisconsin DNR. “They don’t have a history of being in poor condition and being neglected.”

Micheel said the historic rainfall revealed a design flaw in the dams, which are highest in the center. When spillways can’t keep up and water overtops the dam, that slope focused the rushing water toward one side of the dam, where it quickly ate into the hillside.

Investigations showed that the clay structures themselves held, but the sandstone they were attached to gave way.

“They did their job for 50 years,” Micheel said. “Nobody ever envisioned them overtopping. The overtopping showed the weakness.”

Concerns about inadequate dam spillways date back decades to when the Corps of Engineers undertook its first nationwide assessment of dams posing a high risk to life and property. From 1978 to 1981, the Corps inspected 8,818 dams. About one-third were deemed unsafe due to deficiencies, and about 80% of those cited inadequate spillway capacities.

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.

Midwest Storms (copy)

A home in Coon Valley was damaged when Coon Creek flooded and roared through the town on Aug. 27, 2018.

No national standard

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.

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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.

Dams Legacy of Neglect

Water spurts through a wooden section of a spill gate on Lake McQueeney in Texas. 

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.

The AP 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.

Aug. 29: Coon Valley (copy)

Dave Phillips, owner of DC Kustoms on Central Avenue in Coon Valley, cleans out his flood-damaged business on Aug. 29, 2018, after torrential rains sent Coon Creek over its banks and caused several upstream dams to fail.

Focus on safety

In a 1982 report summarizing its nationwide dam assessment, the Corps of Engineers said most dam owners were unwilling to modify, repair or maintain the structures, and most states were unwilling to spend enough money for an effective dam safety program.

Since then, every state but Alabama has created a dam safety program.

But the Great Recession a decade ago forced many states to make widespread cuts to such programs. Since a low point in 2011, states’ total spending on dam safety has grown by about one-third to nearly $59 million in fiscal 2019, while staffing levels have risen by about one-fifth, according to data collected by the Corps of Engineers.

Wisconsin has 11 DNR employees who split their time between dam safety and floodplain management. Another five in the central office work on dam safety, Lourigan said, though only one does that exclusively.

According to data gathered by the AP, Wisconsin’s $752,000 dam safety budget has not changed since 2011.

The state does provide $4 million a year in grants to help dam owners repair or remove aging structures, which Lourigan said is not always enough to meet the demand.

The Association of State Dam Safety Officials says almost every state faces a serious need to pump additional money and manpower into dam safety programs.

“If you don’t have the staff to inspect a dam, or don’t have the authority to do that, you don’t know what the problems are,” said the association’s .

“If you are able to do the inspection but you can’t follow up, and you have dam owners who don’t have the resources to fix their dam, then ultimately you know what the problem is but you can’t get it addressed,” he added.

Awaiting repair

Until Angel’s death in Nebraska this year, the last fatal dam failure in the U.S. occurred on the Hawaiian island of Kauai in 2006.

An earthen wall of the Kaloko Reservoir collapsed during heavy rains and sent a wave of water rushing down a hillside. Seven people — including a pregnant woman — were killed on Bruce Fehring’s property, including his daughter, son-in-law and grandson.

Fehring, who wasn’t there at the time, got a phone call from a neighbor saying something terrible had happened. He was shocked by the scene.

“It took a while to register, and I went, ‘Oh my God, everything’s been washed away,’” Fehring recalled. “I mean, you have no idea the power of water (until) you see what it can do in a very short amount of time.”

Dam owner James Pflueger pleaded no contest to felony reckless endangerment and was sentenced to seven months of confinement and five years of probation. His property company pleaded no contest to seven counts of manslaughter. Prosecutors said Pflueger had filled in the dam’s spillway while attempting to make space for a waterfront development.

The victims’ families and those whose property was damaged agreed to a $25 million civil settlement. Though categorized by the state as low hazard at the time it failed, Kaloko Reservoir is now listed as a high-hazard facility in poor condition. It remains largely unrepaired.

In Wisconsin, the DNR has ordered owners of the failed dams to remove or repair them by 2025. For now the remaining structures have been shored up but are not holding back water.

At least one dam in Douglas County is scheduled for removal this summer. Another has been repaired, but the design is being re-evaluated, Lourigan said. No decision has been made on whether to repair or remove the third.


More than a foot of rain that fell over western Wisconsin in August 2018 overwhelmed the 56-year-old Luckasson dam and four others like it in Monroe and Vernon counties.

Officials in Vernon and Monroe counties are conducting comprehensive watershed studies and waiting to see if they qualify for federal grants to cover the cost of repairs, likely to be millions of dollars.

In September, a little more than a year after the last round of flooding, the Monroe County board established a task force to evaluate the local impacts of climate change and ways to mitigate the damage.

One of the goals is to install weather monitoring stations and warning systems. Another is to re-evaluate the 100-year floodplains based on current land use and rainfall patterns and how best to manage them.

“We need to change what we’re doing here,” Micheel said. “It isn’t going away.”

David A. Lieb, Michael Casey and Michelle Minkoff of The Associated Press and Chris Hubbuch of the Wisconsin State Journal contributed to this report.

Photo gallery: dam safety

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