Is A Major U.S. Dam At Its Breaking Point?
Wolf Creek, Largest Dam East Of The Mississippi, At "High Risk" For Failure
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Play CBS Video Video Dam Is A Time Bomb The Army Corps of Engineers has found one of the nation's largest dams is in danger, as are the people who live near it. Nancy Cordes reports as part of a series on America's failing infrastructure.
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Video Bridge Collapse Probe Underway As families and friends grieve for the victims who were killed during a deadly Minnesota bridge collapse, officials in Minneapolis have started a lengthy investigation. Gwen Belton reports.
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Wolf Creek Dam was built on porous limestone. Over time, water has seeped into cracks in the rock, eroding a Swiss cheese of holes and caves. (CBS)
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An earthen dam at the Kaloko Reservoir shows a breach, center, March 14, 2006, in the northeast part of Kauai in Lilhue, Hawaii. The dam burst without warning. (AP)
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Interactive Span Of The Disaster Photos, video and a look at the Minneapolis bridge that collapsed during rush hour
"The problem is about 250-300 feet below us in the rock," says Mike Zoccola.
Zoccola is with the Army Corps of Engineers, which recently designated the dam at "high risk" for failure, requiring "emergency measures" to reduce an "imminent risk of human life".
“We estimated a range somewhere between about 50 and 120 people, the loss of life — people who live downstream, and possibly fishermen or campers that may be down there,” he tells CBS News transportation and consumer safety correspondent Nancy Cordes.
The devil is in the design. Wolf Creek Dam was built on porous limestone. Over time, water has seeped into cracks in the rock, eroding a Swiss cheese of holes and caves. A sinkhole could cause this entire earthen embankment to collapse.
The first town downstream is Burkesville, Ky. The state has handed out warning radios to all 1,700 residents.Cordes Blogs: Dangerous Dams
"Have they told you how much time you'd have to get out if this thing went off?” asks Cordes.
"I've heard 4 to 6 hours," a restaurant manager said.
There are currently 3,500 dams in the United States listed as unsafe and the list is growing faster than the rate of repair. They may not all be as big as Wolf Creek Dam, but when they fail, the results can be catastrophic.
In recent years, fears about dams giving way have forced evacuations in Maryland, Massachusetts and Missouri. Seven lives were lost last year when a dam broke in Hawaii.
The American Society of Civil Engineers gives the infrastructure report cardnation's dams a "D" and called for fully funded dam safety programs in all 50 states.
“If you live downstream from the dam, it doesn't matter whether the dam was attacked by terrorists or whether it failed because of fatigue and age and lack of repair. The people downstream are all impacted the same,” says Patrick Natale of the American Society of Civil Engineers.
At Wolf Creek Dam, lake levels have been lowered to reduce pressure and crews are working 24 hours-a-day to fill the underwater holes with grout.
Because while the potential damage to Burkesville would be in the millions, the damage to Nashville, Tenn., located further downstream, would be measured in the billions.
Tomorrow we take a look at the state of America's levees. Two years after Hurricane Katrina, many of them are being pushed to the brink.
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