Dam big problem

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Aging Dams in U.S. Expose Thousands to Risk

An investigation identified 1,688 high-hazard dams in unsatisfactory or poor condition.

Georgia led the nation with nearly 200 high-hazard dams in unsatisfactory or poor condition.

Safety officials estimate it would take more than $70 billion to repair and modernize the nation's 90,000 dams.

http://oilbeseeingyou.blogspot.com/2007/07/post-peak-dam-maintenance-or-lack.html
Tuesday, July 31, 2007
Post Peak Dam Maintenance, or Lack Thereof

"Dam failures are of particular concern because the failure of a large dam has the potential to cause more death and destruction than the failure of any other man-made structure. This is because of the destructive power of the flood wave that would be released by the sudden collapse of a large dam."[2] What will be the fate of the world's large dams after peak oil as energy declines, technology falters and budgets for inspection and maintenance of these critical and dangerous facilities begin to be pared back in deference to perceived more immediate societal priorities?

JUNE 1999:

ONE OF CENTRAL OREGON'S DAMS COULD COLLAPSE IN A MODERATE EARTHQUAKE, prompting federal officials to warn people immediately below Wickiup Reservoir to flee to higher ground at the first sign of ground movement. "If people can feel an earthquake in the area, it's probably going to be strong enough to do something to the dam," said Larry Wolf, dam safety expert with the U.S. Bureau of Reclamation in Boise.
It is the first time in the Northwest that the bureau has advised residents to evacuate as standard practice during an earthquake. "Certainly we don't want to create panic, but we want people to be aware," he said. The dam is about 20 miles [32 kilometers] south of Bend and much closer to a number of upscale developments, including Sunriver, which can be packed with 20,000 people on a summer day.
The bureau estimates that floodwaters could endanger roughly 10,000 people. However, Wolf said there would be time for most people to evacuate. The flooded area would roughly follow the channel of the Deschutes River, extending beyond the banks for more than a mile in some places, he said. Because the river channel flattens in some developed areas, floodwaters would take about 14 hours to reach Bend, he said. An earthquake with a magnitude of 5.0 on the Richter scale could cause a catastrophic failure of the 2-mile-long earthen dam. However, he said the chances of such an earthquake are estimated to be about one-tenth of 1 percent each year. Wolf characterized the risk as remote but real. P The Klamath Falls earthquakes in 1993 were pegged at magnitudes of 5.6 and 6.0, and the Scotts Mills earthquake earlier that year in the Willamette Valley hit 5.6.
Wolf said data collected at the dam in recent years indicated that the saturated silt and ash layers of earth beneath the dam could liquefy during an earthquake. The dam was completed in 1949 and holds up to 200,000 acre feet of water, or enough water to cover 200,000 acres to a depth of one foot. The water is used primarily for irrigation in Jefferson County. Wolf said reclamation engineers have suspected for years that Wickiup Dam was at risk. Those fears were confirmed with additional analysis and testing last year. In February, the bureau decided it needed to warn local authorities and the public about the situation and to undertake a $40 million renovation project.
Jim Mumford, who heads the bureau's dam safety division in Boise, said these are far more specific warnings than the bureau has ever issued to Pacific Northwest communities. For example, when the Ochoco Dam near Prineville was at some risk of failing several years ago, the bureau told residents to contact local emergency service officials if there was a problem with the dam. But with Wickiup, he said, there won't be time to await instructions from officials. "This is the first time where we're saying, 'Don't wait for notification. The earthquake is the notification,' " he said. The bureau also has designated escape routes, then posted fliers and sent brochures to area homeowners with maps of those routes. Larry Zakrajsek, who does risk analysis for the bureau, said the agency did not rush to warn people partly because the danger is small and the dam has functioned well for 50 years.
By Gordon Gregory, Correspondent, The Oregonian The Spring Break Quake of 1993, which rattled buildings across western Oregon and caused $30 million in damage, was a harbinger of an 8 or 9 magnitude quake that is in Oregon's future, geologist Donald Hull tells legislators. "It's been 299 years since the last such event," Hull said. "The window of vulnerability is open again." Hull, who is Oregon's chief state geologist, hopes the Legislature will set aside money for better mapping of earthquake hazard zones and for public safety campaigns to let people know what to do when the Big One hits.
The department has been able to retrofit about 60 bridges since the Spring Break quake, but ODOT estimates that at least 1,500 other bridges in western Oregon are in need of at least some earthquake strengthening. Frank Nelson, ODOT's bridge preservation engineer, said eight more bridge projects are planned, and that the department might be able to do an additional four if lawmakers approve a gas tax increase for road repairs. Those projects should at least be enough to keep Interstate 5 -- Oregon's main north-south lifeline -- open in the event of a major earthquake, Nelson said.
Scientific evidence shows that major offshore earthquakes occur off Oregon's coast once every 350 to 500 years. The last one, in 1700, drowned coastal forests and sent tsunami waves across the Pacific so powerful that they destroyed Japanese fishing villages. Such a quake would not only devastate Oregon coastal communities, but inland areas as well. "The Willamette Valley is a big trough full of loose soils, gravel, sands and silts," he said. "When earthquake waves travel through that kind of sediment, they get bigger; they amplify. I'm just praying it won't happen in my lifetime."
Senate President Brady Adams said lawmakers are aware that Oregon is due for another huge earthquake. "It's hard to define in a specific time frame what the risk is. Is it going to happen tomorrow, or 200 years from now?" the Grants Pass Republican said. "There's no question the threat of earthquakes is real, but we also know we have school funding and other needs that are before us today."
Hull said he can't argue with that logic, but still thinks the Legislature should consider increasing at least to a small degree its financial commitment to preparing the state for the Big One. "There's nothing else in our foreseeable future that's going to be as devastating," the state geologist said. "It's not going to do us any good to fund education programs if the school buildings end up falling on kids' heads."

www.csmonitor.com/2007/0913/p02s01-usgn.html

PROBLEM DAMS ON THE RISE IN US
Pennsylvania has seen a fivefold increase in deficient dams since 1999.

By Mark Clayton | Staff writer of The Christian Science Monitor
from the September 13, 2007 edition

The Kaloko dam in Hawaii stood 116 years – until last year when it collapsed after heavy rains, killing seven.

Potential disaster was averted in April in Hollis, N.H., when a dozen families were evacuated and engineers made a controlled breach of an old pond dam to keep it from failing .

Such incidents are warning signs that many of the nation's more than 87,000 dams are in need of repair. Last month's high-profile collapse of the I-35 bridge in Minneapolis focused America's attention on bridge problems. The nation's dams are worse off.

In 2005, the last time the American Society of Civil Engineers rated America's infrastructure, bridges received a "C" grade; dams earned a "D."

Even that rating may be generous, a Monitor analysis of dam-inspection data shows. Since 1999, the number of "high-hazard" dams rated "deficient" has more than doubled, according to data from the Association of State Dam Safety Officials (ASDSO) in Lexington, Ky. High-hazard dams are those whose failures could cause fatalities. In 1999, the US had 546 such dams rated deficient. By last year, it had 1,333.

A second category of "significant-hazard" dams (so-called because they threaten substantial property loss) saw a rise from 339 to 949 deficient dams over the same period. In all, 2.6 percent of the nation's dams are deficient, according to the ASDSO.

"The growth of deficient high-hazard dams in this country is a major issue," says Brad Larossi, legislative chairman for the ASDSO, which represents dam-safety inspectors in all states. "The trend is rising at such a steep slope, much faster than states can do [dam] rehabilitation. Without question the overall trends are clear."

Several factors are behind the rise. Old dams continue to deteriorate or may fail suddenly because of inadequate spillways and trees growing on dams. Many states don't have enough dam engineers to keep up proper maintenance, causing the repair backlog to grow. And as more homes and businesses are built closer to dams, the hazards increase, a phenomenon dam-safety experts call "hazard creep."

Some experts claim that some of the rise is due to better reporting, an encouraging sign. "To be frank, there's been in the past a reluctance in some quarters to identify too many dams as deficient," says Mark Ogden, administrator for dam-safety engineering at the Ohio Department of Natural Resources in Columbus. "But there's also been a strong effort by our association to increase awareness of this problem. We all are realizing we need an honest assessment."

Some states are seeing a faster rise in deficient dams than others. Pennsylvania leads the pack with 215 deficient high-hazard dams, 172 more than in 1999. Not far behind is Ohio, with an increase of 158 . Other states, such as Colorado, New Jersey, and California have seen declines. Some of that is due to better funding, experts say. All three have boosted dam budgets by a third or more since 1999.

Those increases are in contrast to federal dam spending. The nation's dam-safety program, which helps fund safety inspector and engineer training, has not been fully funded in at least five years, Mr. Larossi says. Actual funding is about $5.9 million, well below the $9 million budgeted, he says.

As a result, the number of full-time inspectors has not increased since 1997 (excluding Florida, which claims to have hired 45 inspectors). That leaves each inspector responsible for about 195 dams on average; the ASDSO recommends no more than 50.

"We have seen increased awareness over the importance of adequate funding for state inspectors, but these offices are still understaffed," says Stephanie Lindloff, of American Rivers, an environmental group.

The enormous US dam problem no one is talking about
By Gaylord Shaw
Christian Science Monitor
January 3, 2006

DUNCAN, OKLA. - The landscape of America, at last count, is dotted with 79,272 large dams. Most of them safely deliver bountiful benefits - trillions of gallons of water for drinking, irrigation, and industrial use, plus flood control, recreation, hydroelectric power, and navigation.
That's the good news.
Here, in my opinion, is the bad news: Disaster lurks in thousands of those dams.
At least 3,500 of America's big dams are unsafe, according to inspection reports filed away in obscure nooks and crannies of government offices across the country. Thousands more dams also are unsafe, the American Society of Civil Engineers concluded this year, but no one knows for certain how many because few states have the funds for even cursory safety inspections.
Thus, every moment of every day, unsafe dams form a vast reservoir of danger throughout America. That's not an overstatement. I'm not a professional engineer, but I've spent nearly two-thirds of my 45-year career in journalism studying unsafe dams. I've done on-the-scene reporting on dam failures that killed 175 people and caused billions of dollars in property damage. I've interviewed scores of victims, dozens of state and federal engineers, inspectors, and officials, and examined records on hundreds of dams.
In my view, the cumulative hazard posed by unsafe dams is huge, but it remains largely unexplored by the media. When a dam fails - and records suggest dozens do each year - the events usually are viewed as local, transitory incidents rather than a symbol of a national problem.
Hurricane Katrina underscored the peril of depending on man-made structures for protection against disaster. Failure of the New Orleans' levee system during the storm this year contributed to prolonged flooding and 1,300 deaths.
Months later, as scenes of misery and dislocation lingered in the public mind, President Bush urgently asked Congress to approve $3 billion for the Army Corps of Engineers to begin rebuilding New Orleans' battered levees. The House of Representatives included that amount in a $29 billion hurricane recovery assistance package it passed three days later.
In concept and construction, levees are close cousins of dams. But while politicians flocked to support repair of New Orleans' levees, they've virtually ignored a proposed Dam Rehabilitation and Repair Act which has languished for nearly a year in a House subcommittee. The proposal would authorize the Federal Emergency Management Agency (FEMA) to disperse $350 million over four years to help states repair unsafe dams. Chances of Congress enacting such a repair program anytime soon are slim.
The $350 million program would be a down payment of less than 10 percent toward the estimated $36.2 billion total cost of repairing America's unsafe dams. It also is approximately one-eighth of the amount the president is seeking for repair of the New Orleans' levees.
This is not to suggest that the New Orleans' levees go unrepaired. But from New England to Hawaii more and more aging dams are experiencing problems, with little public awareness. A few large and small examples:

• Taunton, Mass., got national attention in October when a 173-year-old, 12-foot-tall wooden dam above its business district began to buckle. Stores and schools were closed for a week and townspeople headed for higher ground. The crisis eased when the water level behind the dam was lowered. The federal government is now paying 75 percent of the $189,410 cost of tearing down Whittenton Mills Dam and replacing it with a new one.
• In the placid Schoharie River Valley of upstate New York, a volunteer group calling itself Dam Concerned Citizens was formed last month to press for emergency repairs to 182-foot-tall Gilboa Dam, built 80 years ago to supply drinking water to New York City. The dam has been leaking for years. Now citizens have established their own website which distributes emergency notification plans and publicizes preselected evacuation routes for use should the dam fail (www.gilboadaminfo.com).
• Residents of Denver, Colo., population 2 million plus, were warned last month by the Corps of Engineers that serious safety problems have been detected at Cherry Creek Dam, a 141-foot-tall earthen structure. The dam was built 55 years ago on what was then windswept pastureland 10 miles south of Denver. Now the dam looms above Interstate 225, a cluster of office parks and swank homes, a nationally known golf course, and several schools.

Bruce Tschantz, professor emeritus at the University of Tennessee who 25 years ago helped establish the first Office of Dam Safety in the then-nascent FEMA, reached back into classical mythology to fetch a phrase - "the sword of Damocles" - to express his concern about the dangers posed by deficient dams perched above developed areas. (Damocles was a courtier at the court of Dionysius I in the 4th century BC. He was so gushing in his praise of the power and happiness of Dionysius that the tyrant, to illustrate the precariousness of rank and power, gave a banquet and had a sword suspended above the head of Damocles by a single hair.)
"We know what the problems are, we know where they are, and we know how to fix them," Dr. Tschantz said in a telephone interview. It's that next step - actually getting the money to fix them - where we're stalled."
Tschantz doesn't point fingers of blame. But it's clear to me that Congress and several presidents, including the current occupant of the White House, share culpability on the national level, and that too many state and local officials have grown weary of trying to find sources of financing to make dams safer.
Jimmy Carter was the last president to display serious and sustained interest in the issue. He had been in office less than a year when, in the early morning darkness of a Sunday in November 1977, a never-inspected dam in the mountains of his home state of Georgia collapsed and sent a wall of water crashing down upon the campus of Toccoa Falls Bible College - a campus he had visited several times.
The Kelly Barnes Dam on Toccoa Creek dated back to 1899, when a rock-and- timber structure was built across a fast-flowing mountain stream to impound water for a small hydroelectric plant. Later, Toccoa Falls Bible Institute chose the valley below as the site for its campus, took over the power plant and, in 1937, decided to construct an earthen embankment over the original dam, eventually raising the structure's height to 42 feet.
Twenty years later, in 1957, the school abandoned the power plant. For the next two decades, the dam was neglected, visited only by an occasional fisherman or hiker. Pine trees grew to maturity on its downstream slope, sending roots deep into the dam's core. Portions of the steep embankment vanished in a landslide, but there were no repairs, even though water seeped almost continuously from the base of the dam. Finally, the weakened 78-year-old dam collapsed during a rainy night in Georgia.
In the valley below, Eldon Elsberry and two friends were on patrol in the campus fire department's Jeep. When the wall of water hit, it overturned the vehicle. "One minute the water [in the creek] was inches deep, and the next I was swimming for my life," Mr. Elsberry said. "I saw the bank and made for it." He turned and saw one of his friends struggling in the water. "I reached for his hand. He went by so fast I couldn't touch him."
Experts later calculated that the water released by the dam's collapse weighed approximately the same as 7,500 locomotives. As the water crashed across the campus, it destroyed a dormitory and crushed a cluster of mobile homes where married students lived.
Later, in the mud and tangled debris, 39 bodies were found. Twenty were children. College officials said they never hired a private consulting engineer because they had no idea it had safety problems. The state of Georgia never inspected the dam because, at the time, there was no state law requiring such inspections. Few other states had dam safety laws then, either. Pennsylvania was one of the exceptions. Its tough law was spurred by memories of the 1889 collapse of South Fork Dam above Johnstown that killed 2,209 people. Yet even with the strong state law requiring regular safety inspections, another 55 people in the same community died in July 1977 after the failure of Laurel Run Dam, just a few miles from where South Fork Dam triggered the disaster 88 years earlier.
While all states except Alabama now have laws or regulations establishing dam safety programs, enforcement is spotty, largely because of the paucity of inspectors. In Texas, for example, there are only six state employees to inspect nearly 7,500 dams. One Texas official noted that with the current staff level "some dams would not be examined for three centuries."
Let's do the math. Two of my teenaged grandchildren live in Texas. If we count 30 years for each generation, that means all the dams in Texas will be inspected by the time my grandchildren's great-great-great-great-great-great-great-great-great-grandchildren ring in a new year in 2306. Reassuring, isn't it?

• Gaylord Shaw won a Pulitzer Prize for a series investigating the state of the nation's dams for the Los Angeles Times in 1978.

Kariba dam on verge of collapsing

via Kariba dam on verge of collapsing | Radio Dialogue by Sanele Njini
March 19, 2014

A hydroelectric dam bordering Zambia and Zimbabwe threatens the lives of 3.5 million people in the southern African region as it is on the verge of collapsing, local newspaper Zambia Daily Mail reported Tuesday.

The wall of Kariba Dam, one of the world's largest dams measuring 128 meters tall and 579 meters long, has developed weaknesses and may collapse if nothing is done to repair it in the next three years, the report said.

"We are told by engineers that if nothing is done in the next three years, the dam may be swept away," Felix Nkulukusa, chairperson of an intergovernmental committee mobilizing funds for the repair of the dam, was quoted as saying.

The dam, situated in the Kariba Gorge of the Zambezi River basin between Zambia and Zimbabwe, needs 250 million U.S. dollars to be repaired and the World Bank, the African Development Bank and the European Union have so far agreed in principle to fund the repair, he said.

"This is of great concern, as an unstable foundation can wash away the dam, a potential catastrophe event for 3.5 million people along the Zambezi River mainly in Mozambique and Malawi," he added.

In case of the dam swept away, the Cabora Bassa Hydro power plant in Mozambique will be submerged, which may affect 40 percent of electricity generation in the region, he said.

The dam, which controls 40 percent of the total runoff of the Zambezi River, will also have a pushback effect on Zambezi's major tributary, the Kafue River, which may result in the submersion of Lusaka Province, where the Zambian capital of Lusaka is located, he said.

Source: Xinhua

Source: http://www.zimbabwesituation.com/news/zimsit_kariba-dam-on-verge-of-collapsing/
Original: http://www.radiodialogue.com/kariba-dam-verge-collapsing/