Militants Captured Iraq’s Largest Dam, Prompting Fears They Will Unleash A Tidal-Wave On Major City


After a week-long struggle, militants allied with the Islamic State in Iraq and Greater Syria (ISIS) appeared to finally capture the largest dam in Iraq from Kurdish forces on Thursday.

Located in Niveneh province, the city of Mosul first fell under ISIS’ control in June, when forces swept into the city, sending Iraqi security forces fleeing. While Kurdish peshmerga — or security forces — had managed to hold the dam before, and continue to say that the fight for control is still ongoing, ISIS has claimed total dominance of the dam that provides electricity to the city 30 miles away. Situated on the Tigris River, the dam also provides most of the water for the region. “The Mosul dam is now under Islamic State control,” Hisham al-Brefkani, a member of the Nineveh provincial council, told Bloomberg News. “We call on the United Nations, the Security Council, the U.S. and the European Union to help.”

What observers now fear is that ISIS will open the floodgates, sending a tidal wave out against the populace of Mosul. The dam already didn’t have the best track record when it comes to safety. The now-defunct Special Inspector General for Iraq Reconstruction (SIGIR) issued a 2007 report looking into the structural integrity of the dam, which the United States was helping to rejuvenate during its time occupying the country. The results weren’t good. For starters, the whole structure was built on soft sediment, rather than rock, allowing for natural erosion to wear away huge caverns and sinkholes underneath the foundation of the dam. Further, shoddy construction allowed for seepage and other small leaks. The Iraqi government was to take action to allow for long-term solutions while the U.S. would provide short-term fixes.

[An] instantaneous failure of Mosul Dam … could result in a flood wave of 20 meters [65 feet] deep at the City of Mosul

In studying the problems the U.S. was facing in helping patch up the dam, the U.S. Army Corps of Engineers determined in September 2006 that “in terms of internal erosion potential of the foundation, Mosul Dam is the most dangerous dam in the world… If a small problem [at] Mosul Dam occurs, failure is likely.” In a report later that year, the USACE further determined that the odds of the dam failure was “exceptionally high.” As a result, the Corps concluded that in the event of a dam failure, flood waters would likely reach Mosul in approximately three to four hours. Given that Mosul is Iraq’s second largest city, with a population estimated to be around 1,800,000 before ISIS took control earlier this year, evacuation in that short a time frame would be nearly impossible.


The letter then-Ambassador to Iraq Ryan Crocker and General David Petraeus wrote to Iraqi prime minister Nour Al-Maliki in 2007 warning about the risk of failure at Mosul Dam was even more stark. “A catastrophic failure of Mosul Dam would result in flooding along the Tigris River all the way to Baghdad,” the two wrote. “Assuming a worse case scenario, an instantaneous failure of Mosul Dam filled to its maximum operating level could result in a flood wave of 20 meters [65 feet] deep at the City of Mosul, which would result in a significant loss of life and property.” Even though it is 280 miles away, Baghdad would be hit with a 15-foot high wave in such an event.

A 2009 study from two scientists at Mosul University found roughly the same effects, if not worse, should Mosul Dam fail. “Mosul dam will be inundated with the highest flooding level of 235.2 meter above sea level, the maximum flood discharge will be (207632) m3/sec with an average velocity of 3.5 m/sec, while the highest water level will reach (25.3) meter above the natural Tigris River bed within (9) hours from the beginning of the dam failure,” the paper reads. Over half of Mosul itself would be flooded in the even such a catastrophe would occur.

Concern over ISIS unleashing the gates of Mosul Dam and flooding the area may seem extreme, but there’s a reason that everyone is fearing the prospect: they’ve done it before. Last year, in its first major bid to control territory, ISIS invaded and managed to hold Fallujah, the site of some of the heaviest fighting during the U.S.-led war. The Iraqi Army launched a siege of the city to try to root ISIS out, including launching barrel bombs against heavily populated areas. In response, after capturing the nearby dam in February, ISIS closed eight of the ten gates at the dam, flooding the area upstream in an effort to dislodge the Iraqi Army and deprive the area downstream of water. It worked.

Even if the militants don’t unleash a torrent of water upon Mosul’s residents, the control of the dam still gives them enormous leverage and the ability to choose who receives the utilities now under their command. “The most likely uses will be to redirect both to their supporters and cut off both to their opposition,” Paul Sullivan, an adjunct professor at Georgetown University, told Bloomberg News. “If they have real pros on water and electricity systems with them, we may see some very curious events,” he continued. “What might be an even more serious problem is if they have amateurs with them and they make serious errors in judgment. Either way, Iraq is under a greater threat today than yesterday.”

The result of the dam’s capture, and the stranding of thousands of members of the Yazidi religion on a mountain with little to no food or water, is that the Obama administration is once again weighing action against the Islamic State. Until now, the White House has delayed making a decision one way or another until Iraq’s political crisis has been solved and a new prime minister appointed. But with 40,000 people on Mount Sinjar without supplies, and at least 40 children dead already, the U.S. is rapidly considering what its next steps should be — whether in the form of military strikes or airdropping aid. As one administration official told the New York Times, a decision from President Obama could come “imminently — this could be a fast-moving train.”