mercredi 31 octobre 2007

IRAQI DAM 'At Risk of Collapse'

Story from BBC NEWS:

The largest dam in Iraq is at risk of an imminent collapse that could unleash a 20m (65ft) wave of water on Mosul, a city of 1.7m people, the US has warned.

In May, the US told Iraqi authorities to make Mosul Dam a national priority, as a catastrophic failure would result in a "significant loss of life".

However, a $27m (£13m) US-funded reconstruction project to help shore up the dam has made little or no progress.
Iraq says it is reducing the risk and insists there is no cause for alarm.
However, a US watchdog said reconstruction of the dam had been plagued by mismanagement and potential fraud.

In a report published on Tuesday, the Special Inspector General for Iraq Reconstruction (SIGIR) said US-funded "short-term solutions" had yet to significantly solve the dam's problems.
SIGIR found multiple failures in several of the 21 contracts awarded to repair the dam.

Among the faults were faulty construction and delivery of improper parts, as well as projects which were not completed despite full payments having been made.

'Fundamentally flawed'
The dam has been a problem for Iraqi engineers since it was constructed in 1984.
It was built on water-soluble gypsum, which caused seepage within months of its completion and led investigators to describe the site as "fundamentally flawed".
In September 2006, the US Army Corps of Engineers determined that the dam, 45 miles upstream of Mosul on the River Tigris, presented an unacceptable risk.
"In terms of internal erosion potential of the foundation, Mosul Dam is the most dangerous dam in the world," the corps warned, according to the SIGIR report. "If a small problem [at] Mosul Dam occurs, failure is likely."

A catastrophic failure of the Mosul Dam would result in flooding along the Tigris River all the way to Baghdad US letter to Iraqi government.

The corps later told US commanders to move their equipment away from the Tigris flood plain near Mosul because of the dam's instability.
The top US military commander in Iraq, Gen David Petraeus, and US ambassador Ryan Crocker then wrote to Iraqi Prime Minister Nouri Maliki urging him to make fixing the dam a "national priority".

"A catastrophic failure of the Mosul Dam would result in flooding along the Tigris River all the way to Baghdad" the letter on 3 May warned.

"Assuming a worst-case scenario, an instantaneous failure of Mosul Dam filled to its maximum operating level could result in a flood wave 20m deep at the city of Mosul, which would result in a significant loss of life and property."
If that were to happen some have predicted that as many as 500,000 people could be killed.

Alarm bells
Iraqi authorities, however, say they are taking steps to reduce the risk and they do not believe there is cause for alarm.
The Iraqi Minister for Water Resources, Latif Rashid, told the BBC that a number of steps were being taken to tackle the problem, including a reduction in water levels in the reservoir and a round-the-clock operation to pump grouting into the dam's foundations.

Work would also begin next year on a longer-term plan to make the foundations safe by encasing them in a concrete curtain, he added.
The BBC's Jim Muir in Baghdad says the debate over the dam has gone on largely behind the scenes so as not to cause public panic or attract the interest of insurgents.

Are you in Mosul? Are you worried about the risk of the dam collapsing?

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Below is an interesting comment made about the dam on Juan Cole's blog:
On the dam. There was a report made in 1951 by British engineers proposing various sites for dams on the Tigris and the Euphrates. It is fairly widely available in academic libraries, though not on the internet.

When the dams were built under Saddam in the 1980s, other sites were chosen. Although I do not remember what was said about the Mosul dam, the site of the Haditha dam was definitely advised against. So I suppose that is another dam in danger.

However, there is a factor that may not have been taken into account by the US engineers in preparing their assessment of danger, and that is the rate of alluviation. The waters of both the Tigris and the Euphrates carry large amounts of alluvium, washed off the Turkish mountains, and which settles on the bottom when the water is stopped by a dam.

At Samarra, the dam was finished in 1954. When I first went to Samarra in 1977, there was an open lake behind the dam. Now there is only dry land and a river channel. The Mosul dam has been in use for half that time. I suspect there is much less water behind the dam than supposed, and thus less danger, but we have not seen the detailed report. I am only speculating here.

There are other factors; the alluvium might be trapped by the Turkish dams upstream, and they will have the problem in the future. Though it might be a reason the Iraqi engineers are less worried than the US. It depends on how you make the calculations.

Nevertheless, this is a problem typical of an occupation that declares itself not an occupation. The Iraqi government is effectively prevented from acting, and then the occupiers say "not us", fault of the Iraqi government.

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