AUDIE CORNISH, HOST:
In Iraq, a few miles from the frontlines of the war with ISIS looms another threat - the Mosul Dam. It's a massive piece of infrastructure that regulates the Tigris River and generates power to the region. But the dam also sits on weak rock that's rapidly eroding. For years, engineers have been warning that the dam is in danger of collapsing and creating a massive flood that could kill more than a million people. With the recent fighting, their calls have taken on new urgency.
Dexter Filkins recently visited the dam and writes about it in this week's New Yorker magazine. Welcome to the program.
DEXTER FILKINS: Hi.
CORNISH: So you actually went to this dam. And what was it like, and were you scared?
FILKINS: I did. I went to the dam. Well, it's - you know, it's enormous - you know, oceans of cement with this enormous lake behind it. But then I actually ventured into what's called the gallery of the dam, which is the very bottom of the dam. And so you can literally - when you're down there with all the workers, it feels like a mine shaft.
And what was so kind of scary was, it's wet. I mean the water - you know, the giant reservoir is pressing up against the walls right there, and the water's coming through. And you know, everything - everybody's splashing around, and they're trying to find these giant cavities underneath the dam, and they're basically very inexact. I mean it's kind of - again, kind of frightening.
They're sort of poking holes in the floor of the dam, and geysers are shooting up. And it's, like - that means there's a sinkhole under the dam. And so then they wheel up these enormous pumps, and they start pumping cement into it until they can't pump anymore. And that's about as exact as it gets.
CORNISH: Can you give us some sense? What are the scenarios should the dam collapse or be weakened?
FILKINS: It's pretty mind-boggling. Both the United States government and the United Nations have run kind of computer models. And I mean for starters, if the dam cracks, then the whole damn will essentially be gone in 12 hours. And what you would have likely is a hundred-foot wall of water that's probably a mile wide rolling down the Tigris.
And so Mosul, which is a city of 2 million people, would be under 80 feet of water in less than an hour. Most of Iraq's population lives along the Tigris River all the way down to Baghdad, all the way down to Basra. And I think that's the great fear, is that all of the population centers of Iraq would essentially be submerged.
And so the wave they imagine would take about three to four days to reach Baghdad. By the time it got there, it would be about 16 feet high. That's high enough to submerge most of the buildings in Baghdad. It would it would probably submerge the international airport. That would prevent relief crews from coming in.
And what is also terrifying is the level of concern that exists within the U.S. government over the likelihood of the dam's collapse. I mean you start reading these documents, and you're like, oh, my God, these guys are really worried.
CORNISH: As we mentioned, Iraq is obviously still dealing with a war. And how likely do you think it will be that they'll be able to fix this problem or to avoid the catastrophe you're describing?
FILKINS: Well, it's very strange. I mean you're at the dam, and it's this kind of looming - I guess what amounts to an environmental catastrophe. But the ISIS front lines are almost close enough to see. They're just a few miles down the road.
There's a team of Italian engineers - they're from an Italian dam construction company - that has been flown in. They feel pretty confident that they can fix it in time. I think that on one hand, they feel confident, but on the other, when you really sit down and talk with most of the engineers who've studied the problem here, they all say the same thing, which is, the dam is great.
It was really well built, but it's in the wrong place because of the geology underneath the dam. And it's always going to be in the wrong place. And I think when you take that fact and you put it in a place like Iraq where the politics are simply not stable enough to have any kind of predictability, you realize why we're in the problem that we're in.
CORNISH: Dexter Filkins is a staff writer for The New Yorker. Thank you for speaking with us.
FILKINS: Thank you so much. Transcript provided by NPR, Copyright NPR.