The collapse of Mosul Dam would be catastrophic for Iraq. If breached, it could unleash a 180-foot-high wave down the Tigris River basin and drown more than half a million people, with floodwaters reaching as far as the Iraqi capital, about 280 miles to the south.| Bad combination of a shaky foundation, fly ash, shoddy maintenance, and war... |
The dam’s structural problems became evident as soon as the reservoir behind it was filled in 1985. It is built on layers of clay and gypsum, a soft mineral that dissolves when it comes into contact with water, and the dam immediately began seeping. Since then, about 100,000 tons of grouting have been poured into the structure to prevent it from collapsing.