http://www.newyorker.com: A Bigger Problem Than ISIS?
The Mosul Dam is failing. A breach would cause a colossal wave that could kill as many as a million and a half people.By Dexter Filkins
On the morning of August 7, 2014, a team of fighters from the Islamic State, riding in pickup trucks and purloined American Humvees, swept out of the Iraqi village of Wana and headed for the Mosul Dam. Two months earlier, ISIS had captured Mosul, a city of nearly two million people, as part of a ruthless campaign to build a new caliphate in the Middle East. For an occupying force, the dam, twenty-five miles north of Mosul, was an appealing target: it regulates the flow of water to the city, and to millions of Iraqis who live along the Tigris. As the ISIS invaders approached, they could make out the dam’s four towers, standing over a wide, squat structure that looks like a brutalist mausoleum. Getting closer, they saw a retaining wall that spans the Tigris, rising three hundred and seventy feet from the riverbed and extending nearly two miles from embankment to embankment. Behind it, a reservoir eight miles long holds eleven billion cubic metres of water.
A group of Kurdish soldiers was stationed at the dam, and the ISIS fighters bombarded them from a distance and then moved in. When the battle was over, the area was nearly empty; most of the Iraqis who worked at the dam, a crew of nearly fifteen hundred, had fled. The fighters began to loot and destroy equipment. An ISIS propaganda video posted online shows a fighter carrying a flag across, and a man’s voice says, “The banner of unification flutters above the dam.”
The next day, Vice-President Joe Biden telephoned Masoud Barzani, the President of the Kurdish region, and urged him to retake the dam as quickly as possible. American officials feared that ISIS might try to blow it up, engulfing Mosul and a string of cities all the way to Baghdad in a colossal wave. Ten days later, after an intense struggle, Kurdish forces pushed out the ISIS fighters and took control of the dam.
But, in the months that followed, American officials inspected the dam and became concerned that it was on the brink of collapse. The problem wasn’t structural: the dam had been built to survive an aerial bombardment. (In fact, during the Gulf War, American jets bombed its generator, but the dam remained intact.) The problem, according to Azzam Alwash, an Iraqi-American civil engineer who has served as an adviser on the dam, is that “it’s just in the wrong place.” Completed in 1984, the dam sits on a foundation of soluble rock. To keep it stable, hundreds of employees have to work around the clock, pumping a cement mixture into the earth below. Without continuous maintenance, the rock beneath would wash away, causing the dam to sink and then break apart. But Iraq’s recent history has not been conducive to that kind of vigilance.
In October, Iraqi forces, backed by the United States, launched a sprawling military operation to retake Mosul, the largest city under ISIS control. The battle has sometimes been ferocious, with Iraqi soldiers facing suicide bombers, bombardments of chlorine gas, and legions of entrenched fighters. Although some Iraqi leaders predicted a quick success, it appears that the campaign to expel ISIS will be grinding and slow. And yet the biggest threat facing the people of northern Iraq may have nothing to do with who controls the streets.
In February, the U.S. Embassy in Baghdad issued a warning of the consequences of a breach in the dam. For a statement written by diplomats, it is extraordinarily blunt. “Mosul Dam faces a serious and unprecedented risk of catastrophic failure with little warning,” it said. Soon afterward, the United Nations released its own warning, predicting that “hundreds of thousands of people could be killed” if the dam failed. Iraq’s leaders, apparently fearful of public reaction, have refused to acknowledge the extent of the danger. But Alwash told me that nearly everyone outside the Iraqi government who has examined the dam believes that time is running out: in the spring, snowmelt flows into the Tigris, putting immense pressure on the retaining wall.
If the dam ruptured, it would likely cause a catastrophe of Biblical proportions, loosing a wave as high as a hundred feet that would roll down the Tigris, swallowing everything in its path for more than a hundred miles. Large parts of Mosul would be submerged in less than three hours. Along the riverbanks, towns and cities containing the heart of Iraq’s population would be flooded; in four days, a wave as high as sixteen feet would crash into Baghdad, a city of six million people. “If there is a breach in the dam, there will be no warning,” Alwash said. “It’s a nuclear bomb with an unpredictable fuse.”
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Shortly after the dam went into use, Nadhir al-Ansari, a consulting engineer, made an inspection for the Ministry of Water Resources. “I was shocked,” he told me. Sinkholes were forming around the dam, and pools of water had begun bubbling up on the banks downstream. “You could see the cracks, you could see the fractures underground,” Ansari said. The water travelling around the dam, known as “seepage,” is normal in limited amounts, but the gypsum makes it potentially catastrophic. “When I took my report back to Baghdad, the chief engineer was furious—he was more than furious. But it was too late. The dam was already finished.”
To control the erosion, the government began a crash program of filling the voids with cement, a process called “grouting.” Meanwhile, Iraqi officials rushed to build a second dam, near a town called Badush, which could help prevent flooding in case the Mosul Dam collapsed. By 1990, just six years later, the new dam was forty per cent complete. Then Saddam sent his Army into Kuwait, sparking the Gulf War, and he ordered all the earthmoving equipment stripped from the Badush site and sent to the front lines. When the United States and its allies arrived to expel the Iraqis from Kuwait, they bombed all the equipment. After the war, inspectors from the International Atomic Energy Association discovered stockpiles of nuclear materials near Badush, apparently part of Saddam’s secret weapons program. The U.N. imposed economic sanctions on Iraq, impoverishing the country for a decade. Work on Badush never resumed. “Nobody wanted to go anywhere near the place,” Adamo told me. “This is the story of Iraq.”
When the Americans invaded in 2003, they discovered a country shattered by sanctions. Power plants flickered, irrigation canals were clogged, bridges and roads were crumbling; much of the infrastructure, it seemed, had been improvised. The U.S. government poured billions of dollars into rebuilding it, and in 2006 the U.S. Army Corps of Engineers began several assessments of the Mosul Dam. The first report was dire, predicting “mass civilian fatalities” if it failed. “In terms of internal erosion potential of the foundation, Mosul Dam is the most dangerous dam in the world,” it said.
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Naemi told me that some American officials had come to him earlier this year to warn that the dam was going to break, and confronted him with satellite photos that showed water from the reservoir seeping through the sides of the dam. “I told them it was not important,” he said. “I explained to them that there was no problem—and they agreed with me.” The senior American official, frustrated at the years of inaction, told me that the Americans were not persuaded by Naemi: “He is not going to tell us the sky is falling. We shared the data that showed the risks of the dam, and it’s terrifying.”
The potential disaster has presented American officials with a public-relations quandary: the people they are trying to help won’t publicly concede that there’s a problem. In response, U.S. officials have gone silent. It took me more than a hundred phone calls, e-mails, and visits before a single American official was granted permission to speak to me on the record; even then, three other State Department officials listened in on the conversation. “We don’t want to publicly embarrass the Iraqis,” the senior American official told me.
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Inside the gallery, the engineers are engaged in what amounts to an endless struggle against nature. Using antiquated pumps as large as truck engines, they drive enormous quantities of liquid cement into the earth. Since the dam opened, in 1984, engineers working in the gallery have pumped close to a hundred thousand tons of grout—an average of ten tons a day—into the voids below.
To keep the ground beneath the dam stable, workers in the gallery pump a cement mixture into the earth. Without continuous maintenance, soluble rock in the foundation would wash away, causing the dam to sink and then break apart.
Up close, the work is wet, improvisatory, and deeply inexact. Gauges line the walls of the gallery, programmed to detect changes in pressure; water seeps through cracks in the floor. Ordinarily, the pressure is much higher on the upstream side—because the water is pressing against the dam wall. If the pressure readings on the two sides of the gallery begin to converge, water is probably passing underneath. “That means there’s a leak,” Hussein al-Jabouri, the deputy director of the dam, said, waving at a gauge.
Like his boss, Jabouri has worked at the dam since he was a young engineering graduate. Now, he told me, he is as sensitive to the dam’s changes as the electronic gear buzzing around him. Jabouri gave a signal—“Come”—and a crew of engineers wheeled one of the giant pumps into position. At his feet, all along the gallery floor, were holes that serve as guides for the industrial drills the engineers use to probe the voids.
At Jabouri’s command, the engineers began pushing a long, narrow pipe, tipped with a drill bit, into the earth. The void they were hunting for was deep below—perhaps three hundred feet down from where we were standing. After several minutes of drilling, a few feet at a time, the bit pushed into the void, letting loose a geyser that sprayed the gallery walls and doused the crew. The men, wrestling the pipe, connected it to the pump. Jabouri flicked a switch, and, with the high-pitched whine of a motorcycle engine, the machine reversed the pressure and the grout began to flow, displacing the water in the void. “It’s been like this for thirty years,” Jabouri said with a shrug. “Every day, nonstop.”
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Theoretically, it’s possible that all the voids underneath the Mosul Dam could be filled—that all the gypsum could be replaced with grout. “Not in our lifetimes,” an Army Corps of Engineers specialist told me. In the meantime, he said, “there are just enormous quantities of gypsum that are washing away.”
ROSAL