'Tsunami wave' could kill hundreds of thousands within hours if damaged dam collapses
America warns of hundreds of thousands of Iraqi deaths and government helpless to evacuate those in Islamic State-controlled areas
Iraq's Mosul Dam faces "unprecedented" risk of a "catastrophic failure" that would unleash a wave of water which could flatten cities and kill hundreds of thousands within hours, the US has said.
The American government issued an unusually stark warning of the horrors that face Iraq if the dam gives way, describing a "tsunami-like wave" that would crush nearly a third of the country.
Iraq's power grid could be entirely knocked out and parts of major cities would be underwater for weeks like areas of New Orleans after Hurricane Katrina, the US said.
The Iraqi government would be unable to direct an evacuation because Islamic State of Iraq and the Levant (Isil) still controls much of the territory near the dam and so people need to prepare to evacuate on their own, the US said.
The dam was built in 1984 but has fallen into severe disrepair over decades of dictatorship, war and instability in Iraq. The government has struggled to convince foreign companies to take up a contract to maintain the dam while fighting with Isil rages nearby.
The US embassy in Baghdad said long-running deterioration meant the danger was now at an "unprecedented" level.
While there was "no specific information that indicates when a breach might occur", the US said Iraq's government should begin setting up an emergency notification system to warn the roughly 1.5 million people in the flood path.
"Mosul Dam faces a serious and unprecedented risk of catastrophic failure with little warning," the US said. "A catastrophic breach of Iraq’s Mosul Dam would result in severe loss of life, mass population displacement, and destruction of the majority of the infrastructure within the path of the projected floodwave."
The dam is upstream from Mosul, which is Iraq's second largest city and has been under Isil control since June 2014 but the dam was soon recaptured by Peshmerga and other foreign forces.
Parts of the city could be under 45 feet of water within hours of a dam breach, the US said, giving residents little time to flee.
The wave of water would sweep as far south as Samarra; killing people, crushing buildings, laying waste to farm land and knocking out power plants.
The flood water would probably reach Baghdad within three days and bring chaos to the Iraqi capital with "increased health hazards, limited to no mobility, and losses of homes, buildings, and services".
"Much of the territory projected to be damaged by a dam breach is contested or Isil-controlled, suggesting an authority-directed evacuation is unlikely, and that some evacuees may not have freedom of movement sufficient to escape," the US said.
"The lack of an authority-directed evacuation effort probably will result in some vulnerable groups - like the sick, disabled, and elderly - being left behind."