The Mosul Dam is one element of Iraq’s infrastructure that has survived the war so far, but which is apparently seriously threatened. Because was built on gypsum, which dissolves in water, it threatens to fail catastrophically as the result of small initial problems. A report from the US Army Corps of Engineers warned that the dam’s failure would drown Mosul under nearly 20m of water and parts of Baghdad under 4.5m. The 2006 report explained that:
In terms of internal erosion potential of the foundation, Mosul Dam is the most dangerous dam in the world. If a small problem [at] Mosul Dam occurs, failure is likely.
According to the BBC, the US Special Inspector General for Iraq Reconstruction (SIGIR) has stated that the dam’s foundations could give away at any moment. The report from the Corps of Engineers states that the dam’s failure could cause 500,000 civilian deaths. General David Petraeus and the American Ambassador to Iraq have both written to the Iraqi government expressing their severe concern.
The dam is 2,100m across and contains 12 billion cubic metres of water. It generates about 320 MW of electricity. Previous attempts at addressing the gypsum issue seem to have been botched. According to the Washington Post “little of the reconstruction effort led by the U.S. Embassy has succeeded in improving the dam.” Stuart Bowen, the special inspector general reviewing the efforts has said that “[t]he expenditures of the money have yielded no benefit yet.”
Today, the Iraq government has officially stated that concerns about a possible collapse are misplaced and that the dam is constantly monitored. Ongoing actions include reducing the amount of water in the reservoir and pumping grout into the foundation (a liquefied mixture of cement and other additives). Work is meant to begin next year on wrapping the foundations in concrete to make them more secure.
Obviously, a catastrophic dam collapse is the last thing Iraq needs. Hopefully, the dam will hold until a sensible refit can be carried out, and it will not find any wayward coalition munitions or insurgent bombs helping it towards disintegration.
“Mahmoud explains that the dam leaks, but is structurally sound. This is confirmed, he says, by data from a full array of piezometers–mostly downstream, but some above the dam. The foundation rests on three strata of gypsum. There is some seepage beneath. But the dam engineers, a German-Italian joint venture called GIMOD, designed an aggressive grouting program to deal with this. Concrete lined grout galleries, each some 1,600 m in length, extend from each wing to the center, in the dam’s core. Mounted lines on the gallery walls deliver bentonite, cement, water and air to make grout for portable drilling machines. Four crews are working in one gallery. There are 12 machines in all. Another wall-mounted line extracts water. Grout injection wells are evenly spaced approximately 10-20 m apart. The grout curtain extends to a depth of 90 m. The dam consumes some 50 mt of grout a day, under normal maintenance. Voids throw the program into emergency status and have consumed up to a quarter million tons of grout a day. Mahmoud believes better grout would reduce the consumption. Quality grout is one more material that has been hard to come by, either because of post-Desert Storm sanctions or because of the regime’s other priorities.”
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Water pouring out of the reservoir of the Teton Dam in Idaho following its catastrophic failure on June 5, 1976.
During an armed conflict, a dam is to be considered as an “installation containing dangerous forces” due to the massive impact of a possible destruction on the civilian population and the environment. As such, it is protected by the rules of International Humanitarian Law (IHL) and shall not be made the object of attack if that may cause severe losses among the civilian population. To facilitate the identification, a protective sign consisting of three bright orange circles placed on the same axis is defined by the rules of IHL.
Cascade Failure in River Systems with Multiple Dams
It is time once again to speak of dams and things. It is not that I’m becoming paranoid about dams. At least I don’t think I am. It is simply that the more I see and read and hear the more I believe dams, and their other attendant water control/management infrastructure, to be perhaps the greatest infrastructure risk for society during the long, painful implosion of the global economy, and our individual national economies, that will follow peak oil. It is not the greatest overall risk, of course.
The greatest risk to our bloated human population will be the collapse of our industrialized agriculture system and our inability to produce and distribute sufficient food for our global numbers, especially with the collapse of the global distribution system with the steady decline of oil and natural gas availability, on which modern agriculture and food processing are critically dependant. Death by starvation is a slow, tortuous process, taking the young, the old and the ill first. But the collapse of a large dam, or a series of dams of various sizes in a common watershed in a cascade failure, represents a sudden and inescapable catastrophe for all of those in harm’s way downstream from the collapse.
As the above report notes, “Engineers design dams and their spillways to cope with the extreme floods that they predict using past records of streamflow and precipitation. It is vital that spillways are adequately sized – if a spillway is overwhelmed there is a high risk of a dam break. ….. But the assumption that we live in a stable climate no longer holds. Streamflow patterns are changing and are almost certain to continue to change, and at an accelerating rate, over the lifetime of the world’s dams. As noted in a World Commission on Dams’ background paper: “The major implications of climate change for dams and reservoirs are firstly that the future can no longer be assumed to be like the past, and secondly that the future is uncertain.”.”
As it looks at the moment, allowance for climate change is not likely to be built into the design of new dams anytime soon, let alone upgrading the existing dam inventory. There seems to be a large dose of denial amongst those involved in the dam designing/building industry. “While the climatic future is indeed filled with uncertainties, one trend upon which climatologists almost universally agree is that we will see (and indeed are already seeing) more extreme storms and increasingly severe floods. And yet, alarmingly, the vast majority of dam proponents and operators deny that climate change is even relevant for dam safety. The president of a major dam engineering firm told this author last year that climate change is “a problem for dams in 20 or 30 years, but not now.”.”
Metafilter on the Mosul Dam.
Adam Smith, hundreds of years ago, wrote:
“Let us suppose that the great empire of China, with all its myriads of inhabitants, was suddenly swallowed up by an earthquake, and let us consider how a man of humanity in Europe, who had no sort of connection with that part of the world, would be affected upon receiving intelligence of this dreadful calamity. He would, I imagine, first of all, express very strongly his sorrow for the misfortune of that unhappy people, he would make many melancholy reflections upon the precariousness of human life, and the vanity of all the labours of man, which could thus be annihilated in a moment. He would too, perhaps, if he was a man of speculation, enter into many reasonings concerning the effects which this disaster might produce upon the commerce of Europe, and the trade and business of the world in general. And when all this fine philosophy was over, when all these humane sentiments had been once fairly expressed, he would pursue his business or his pleasure, take his repose or his diversion, with the same ease and tranquillity, as if no such accident had happened. The most frivolous disaster which could befall himself would occasion a more real disturbance. If he was to lose his little finger to-morrow, he would not sleep to-night; but, provided he never saw them, he will snore with the most profound security over the ruin of a hundred millions of his brethren, and the destruction of that immense multitude seems plainly an object less interesting to him, than this paltry misfortune of his own.”
The Americans are being smart in giving a dire warning.
If the dam collapses, they can say: “We warned you!”
If it doesn’t, nobody will ever really notice.
Bomb threatens ‘at risk’ Iraq dam
In Middle East
A truck laden with explosives blows up near an Iraqi dam that US engineers had said was at risk of collapse.
A truck laden with explosives has blown up near a controversial dam in Iraq, killing one person and damaging the main access bridge, Iraqi police said.
Operation Chastise was the official name for the attacks on German dams on 17 May 1943 in the Second World War using a specially developed “bouncing bomb”. The attack was carried out by Royal Air Force No. 617 Squadron, subsequently known as the Dambusters. The Moehne and Eder dams were breached in these attacks, causing a catastrophic flooding of the Ruhr valley, while the Sorpe dam sustained only minor damage.