ISIS militants captured Iraq's largest dam on Thursday, wresting it away from the Kurdish Peshmerga's control and fueling fears as to what the capture of one of the country's key piece of infrastructure could mean.

ISIS's control of the Mosul Dam could be catastrophic for Iraq. The destruction of the dam would trigger a humanitarian crisis beyond the scope of anything Iraq has experienced so far in its struggle with the Al Qaeda offshoot. Mosul, Iraq's second largest city, is located within 30 miles of the dam and would be most effected by the structure's failure or destruction.

In 2009, two professors at Mosul University wrote a prescient study looking at what would happen if the dam ever failed. In a worst-case scenario, a "flood wave will cover about 53.6% of the Mosul City" beneath 82 feet of water. Somewhere between 58 and 100 square miles of farmland would also be washed away in the deluge.

In a best-case scenario, according to the professors, 34.5% of Mosul would be submerged within eight hours.

The flooding would not be limited to Mosul, either. Instead, the Tigris River would dangerously overflow its banks all the way to Baghdad.

"Within three days Baghdad could be flooded by five meters of water," Richard Coffman, an assistant professor of civil engineering at the University of Arkansas who has conducted research on the Mosul Dam, told Business Insider.

Here's a look at how the dam could affect all of northern Iraq Google Maps



Worse still, even if ISIS does not purposefully destroy the dam improper maintenance could still trigger the structure's collapse. Due to the dam's construction on a soluble bedrock, constant grouting is necessary to keep the structure from collapsing in upon itself.

"Grouting is typically a learned skill done by grouting experts," Coffman told Business Insider. "I can't speak to the skill of the insurgents, but I'd imagine they might have some trouble with this."

In 2007, the Army Corps of Engineers found that the dam had an "exceptionally high" probability of failure. An estimated half-million people were predicted to die from the dam's collapse due to flooding, power outages, loss of farmland, and eventual drought and famine.

Even if ISIS was able to keep the dam operational, the structure still poses a serious strategic risk. The dam is a major source of power for Mosul and the surrounding areas. ISIS could hypothetically use the dam to starve opponents of electricity, thus sapping opposition of their will to fight.

Ominously, one of ISIS's English-language propaganda magazines recently compared the group to Noah's flood — exactly the kind of Biblical disaster that the terrorist organization could now have the power to create.