Dexter Filkins writes: 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. [Continue reading…]