The Mosul Dam is failing. A breach would cause a colossal wave that could kill as many as a million and a half people, displace 4 million, and flood Baghdad, a city of 6 million people, leaving them without food and electricity.

The dam, twenty-five miles north of Mosul, regulates the flow of water to the city, and to millions of Iraqis who live along the Tigris. It rises three hundred and seventy feet from the Tigris riverbed and extends nearly two miles from embankment to embankment. Behind it, a reservoir eight miles long holds eleven billion cubic meters of water.

The dam is tended to by a crew of nearly 1500 Iraquis.  Why? Completed in 1984, the dam sits on a foundation of soluble rock. To keep it stable, employees have to work around the clock, pumping a cement mixture into the earth below. Without continuous maintenance, the rock beneath will 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. Unfortunately, Mosul has been and remains at the center of an ongoing war with ISIL and two Battles of Mosul (2014, 2016-7). The US and UN have released statements warning of the eventual consequences if the dam is compromised.

Read more about the Mosul Dam in this piece from the New Yorker.