The collapse of the Mosul dam may be imminent.

[jwl]

I wonder what could be done if anything to avert this crisis.

I fear the answer is “nothing”.

Even just evacuating the area would be a monumental task because of the sheer amount of people involved and the dangers posed by ISIS militants. Even if they could scrap up enough buses and cars and bicycles to evac all the people and could successfully organize it despite the demonstrated incompetence of large scale Iraqi efforts and the threats that would be faced, where would the people be able to even go?

[There is a regulatory dam just downstream that will buy an hour and though its incomplete, the Badush Dam will buy about 20 minutes. In addition, before the Dam breaks their will be visible cracks for about two to three and a half hours before it gives way. In the worse case scenario I seen in a paper study released in 2009, it will take roughly five hours for Mosul to flood and up to 54% of the city will flood.

Now that's bad, but there is enough warning for people to evacuate and there is enough lead time for citizens of Mosul to relocate now out of the main flood area of the city.

The historical records on evacuating cities is dismal.

Let's do a little comparison – New Orleans, Louisiana, USA and Mosul, Iraq.

New Orleans is about half the population of Mosul. They knew the exact day and hour that Hurricane Katrina would hit the city. Evacuation started 50 hours before the storm's landfall. In a nation that was at peace, in the world's wealthiest society with ample resources, tens of thousands of people were left in the city, which as we all know flooded.

Now Mosul – twice as many people. No one knows exactly when the disaster is going to hit, which makes it harder to motivate people to move out of the way. The area is economically devastated, outside help prior to the disaster will be meager to non-existent, and the region on a war footing. Anyone left in Mosul in the flood areas will die, there will be no “shelters of last resort” for those who either can not or will not leave. Your description gives maybe 3.5 to 5 hours of warning of imminent disaster. You can not evacuate a city of 600,000+ in 5 hours, much less 3.5. Casualties will be in the high tens of thousands at best, more likely into the six digits.

It's not going to look like Hurricane Katrina, it will look like the Boxing Day Tsunami as far as death tolls go (actually, will probably exceed that death toll and not over an extensive region of several nations but in just one city), and that's just one city in the path of the water. There are, as we know, several more.

Of course that rather raises the question of why it takes so long to evacuate a city. Even given that all the roads are blocked up, you can walk out of a city in less than 5 hours.

[Purple]

Of course that rather raises the question of why it takes so long to evacuate a city. Even given that all the roads are blocked up, you can walk out of a city in less than 5 hours.

Probably because evacuation is not just about physically getting one person out. It's about getting a huge amount of people out safely. And this is crowd control on an epic level. You have to keep everyone calm and coordinated so as to ensure they do not panic and stampede/get into crashes and funnel them carefully through the streets to ensure they don't just clog up the roads. This is all assuming the road network is even in any shape to take that many people all going the same way at once. Modern cities get clogged up when a fraction of their people want to go to work every morning. And once that's all said and done and the people are out of the city your job has only begun. You have to sort them and funnel them somewhere where they can actually be cared for. It's a hugely complex and difficult thing.

[Simon_Jester]

Right- and suppose you tell everyone "go do that." You now have large, uncoordinated crowds of people standing around in empty fields and parking lots ten miles outside the city center. With no supplies except maybe a backpack or a hobo-style bindle or in very lucky cases a wheelbarrow they pushed in front of them. They may have a little food and water... but not much.

How are you going to take care of all those people? There's nowhere near enough shelter to put them all in in such a small area; you'd have to spread them out for days of walking to get them to existing buildings that can accommodate them, even under overcrowded conditions.

Plus, large chunks of the population have been left behind because they are physically unable to walk at a brisk pace for five hours- the sick, the disabled, the elderly, and small children whose parents aren't strong enough to carry them for ten miles.

The matter is worse in a modern city with large freeways and the like, because a freeway often acts as a barrier to human foot traffic trying to walk across it- the road is generally fenced off and elevated precisely because under normal conditions you don't want anyone being able to access it. This would have the effect of channelizing pedestrian evacuations, and making it much easier for people to get lost and caught in cul de sacs.

[Simon_Jester]

How could the Iraqi government evacuate Mosul if they are not holding it?

[blinks]

Sorry; by this time I was starting to fall apart from sleepiness; I managed to miss that. Although I think that the Iraqi government evacuate a city in an orderly fashion at all" stands, it just applies to cities further down river.

[LaCroix]

Heavy construction machinery is also rare in that area considering the coalition made an effort to bomb them (and rightly so) because ISIS decided to use it to crush historical sites.

If that is the case, then in hindsight, they weren't "rightly so" to bomb the equipment. The fact it might be needed would have been difficult to foresee, however.

You are implying that ISIS would have allowed the people maintaining the dam to use the machinery in question for this task... Which I doubt. If they did care, they'd never taken the machinery away from the (ongoing) preservation efforts, to start with.

[jwl]

Heavy construction machinery is also rare in that area considering the coalition made an effort to bomb them (and rightly so) because ISIS decided to use it to crush historical sites.

If that is the case, then in hindsight, they weren't "rightly so" to bomb the equipment. The fact it might be needed would have been difficult to foresee, however.

You are implying that ISIS would have allowed the people maintaining the dam to use the machinery in question for this task... Which I doubt. If they did care, they'd never taken the machinery away from the (ongoing) preservation efforts, to start with.

Thanas seemed to be implying that te reason there is a lack of equipment is that the coalition bombed it (so, presumably when any land gets taken back the equipment can't be). If that is not a major reason for lack of equipment, then they would have been right to attack it, barring other unforeseen consequences.

[jwl]

Right- and suppose you tell everyone "go do that." You now have large, uncoordinated crowds of people standing around in empty fields and parking lots ten miles outside the city center. With no supplies except maybe a backpack or a hobo-style bindle or in very lucky cases a wheelbarrow they pushed in front of them. They may have a little food and water... but not much.

How are you going to take care of all those people? There's nowhere near enough shelter to put them all in in such a small area; you'd have to spread them out for days of walking to get them to existing buildings that can accommodate them, even under overcrowded conditions.

Plus, large chunks of the population have been left behind because they are physically unable to walk at a brisk pace for five hours- the sick, the disabled, the elderly, and small children whose parents aren't strong enough to carry them for ten miles.

The matter is worse in a modern city with large freeways and the like, because a freeway often acts as a barrier to human foot traffic trying to walk across it- the road is generally fenced off and elevated precisely because under normal conditions you don't want anyone being able to access it. This would have the effect of channelizing pedestrian evacuations, and making it much easier for people to get lost and caught in cul de sacs.

You don't need to walk at a brisk pace for five hours to get out of a city: the only reason I mentioned five hours is because that was the timespan broomstick quoted: 1-2 hours is a more accurate number.

The point I was assuming broomstick was trying to make was that the floodwater itself would drown those still left in the city when the floodwaters reach there. That danger is only going to stay for as long as the floodwaters remain in the city, which means they only need to take supplies for a few days and then they can go back again. Even if they don't have supplies to last that long, people can go a few days without food and still survive. Also remember that these people are Muslims: they are used to fasting because of Ramadan.

Do you really think people are going to get lost in a city they have lived all their lives?

[NecronLord]

Heavy construction machinery is also rare in that area considering the coalition made an effort to bomb them (and rightly so) because ISIS decided to use it to crush historical sites.

You care more about ruins than peoples lives. Fuck the ruins, they aren't worth one penny over someone's life. When you personally go there and fight for those ruins like other Iraqi and Syrian Archaeologists have then you can bitch about the ruins, you at least would have the right to do so. Otherwise STFU over those ruins.

If one person dies because ruins were prioritized over a Dam that provides jobs, electricity, and water to millions of people, that is one more person you are saying didn't deserve to live because a ruin is more important. If the worst case happens then this is 1.5 million in advance asshole for the people who I value more than your stupid ruins you prattle about.

While I don't disagree that preventing the destruction of a modern city is more important than protecting the ruins of an ancient one, the 'you aren't personally willing to put yourself in danger therefore you have no right to speak' is a very weak argument. How have you, Honorius, personally exposed yourself to danger to protect civilian lives in Iraq and Syria?

[NecronLord]

Do you really think people are going to get lost in a city they have lived all their lives?

Seems reasonable? I have not memorized every street of my city, I'm not a taxi driver.

[jwl]

Do you really think people are going to get lost in a city they have lived all their lives?

Seems reasonable? I have not memorized every street of my city, I'm not a taxi driver.

Well no, but I imagine you wouldn't go down the routes you know nothing of. You would know routes to get out of a city from your current position or the city centre, no?

[salm]

Which area is in danger of getting flooded? Is it only mainly the center or is the diameter larger than the city?

[Sky Captain]

If the floodgates cant't be opened then even if foundation don't fail it is only a matter of time before water levels reach the edge and start overflowing causing uncontrolled erosion at the base of a dam and subsequent failure.

[Broomstick]

You don't need to walk at a brisk pace for five hours to get out of a city: the only reason I mentioned five hours is because that was the timespan broomstick quoted: 1-2 hours is a more accurate number.

Someone in shape and without significant obstruction or burden can cover 5-8 km in an hour (I base that on personal experience - several times I walked from the Chicago Loop to my home in Rogers Park, which is definitely through an urban area, and usually made the 16 km trip in two hours).

However, if you are walking in a crowd, which is what would occur here, you will move at a slower pace unless you want to start shoving slower people out of your way. Which is not a good idea to do in a crowd under high stress conditions. If you are carrying your worldly possessions/valuables, or a child, you will move slower. If you are pregnant, elderly, or disabled you will move slower.

In addition, most people are not going to be able to walk at that pace more than an hour or two with needing to rest. Clumps of resting people will become an obstacle. Based on historical accounts of mass movements of people, you will also have a certain percentage of people simply drop dead from stress, which will also be an obstacle.

In other words, this will be enormously different that an unobstructed, unburdened stroll through a cityscape.

Yes, some people will be able to get out in that time frame - the highly fit, and possibly the slightly ruthless. That means the survivors will mostly be young men.

The point I was assuming broomstick was trying to make was that the floodwater itself would drown those still left in the city when the floodwaters reach there. That danger is only going to stay for as long as the floodwaters remain in the city, which means they only need to take supplies for a few days and then they can go back again.

No, they can't.

Why do you think a flood of that sort will leave buildings intact? Honestly, do some some research. A failed-dam flood sweeps away a lot of buildings, bridges, destroys roads, and leaves mud and debris meters deep in its wake. Sure, they can go back to a wrecked city with no power, no clean water, and little to no shelter... but why would they? Other than to see for themselves the level of destruction, at which point they're going to go elsewhere for food, water, and shelter.

Even if they don't have supplies to last that long, people can go a few days without food and still survive. Also remember that these people are Muslims: they are used to fasting because of Ramadan.

Ramadan doesn't mean going days without food, it means going without food during daylight. That's a big difference.

Do you really think people are going to get lost in a city they have lived all their lives?

Yes.

Happens all the time without a natural disaster occurring. After the flood, there may be much of the city unrecognizable.

[Simon_Jester]

Do you really think people are going to get lost in a city they have lived all their lives?

Seems reasonable? I have not memorized every street of my city, I'm not a taxi driver.

Well no, but I imagine you wouldn't go down the routes you know nothing of. You would know routes to get out of a city from your current position or the city centre, no?

Would you know how to get out of your city ON FOOT, while avoiding low-lying areas that will flood first?

Are you prepared to pronounce a sentence of death for those who are unable to do so, or who get turned around and walk in the wrong direction for half an hour?

[SpottedKitty]

Why do you think a flood of that sort will leave buildings intact? Honestly, do some some research. A failed-dam flood sweeps away a lot of buildings, bridges, destroys roads, and leaves mud and debris meters deep in its wake.

<nod> A good starting point might be to look into what happened in Germany in WW2 when the Ruhr and Eder valleys were flooded after the Dambuster raids. There was a TV documentary on the subject not long ago, IIRC the effect is not unlike a tsunami. The only real defence is "be somewhere else" — a lot of urban structures just won't hold up through this sort of thing.

[Patroklos]

That really depends on the geography of the area. While the river banks themselves and the property right on them might see destuctive flooding as well as any tributaries along it until they are above the crest level, most of Mosul and the areas around it are relatively flat. This will largely looke like Katrina, where the immediate coastal areas saw destructive weather but the vast majority of the flooded areas were simply submerged. This is Mosul



Katrina is an apt comparison given the grossly exaggerated loss of life expectations. On million? Seriously? You would have to drown every resident of Mosul to get that number. The damn holds 2.7 cubic miles of water, do some quick calculations on what the crest will be spread over just the area of Mosul itself.

A disaster? Absolutely. Will this potentially kill many thousands? Probably. A million, certainly not, and you should know better if you are repeating that.

[Broomstick]

With death estimates it helps to know if those are estimates of DIRECT deaths - that is, from the flood waters themselves - or with the addition of knock-on effects.

Knock-on effects are deaths from lack of clean water, from crowd panic, from subsequent fires (yes, it is in fact fairly common for flooded cities to burn, it's happened several times in the US over the past decade or two that I can recall, including in 2008 in my area where a subdivision burned down after it was flooded), and so on. If it happens during extreme weather, or if you get an outbreak of water-borne disease, the casualties can be quite high.

[madd0ct0r]

That really depends on the geography of the area. While the river banks themselves and the property right on them might see destuctive flooding as well as any tributaries along it until they are above the crest level, most of Mosul and the areas around it are relatively flat. This will largely looke like Katrina, where the immediate coastal areas saw destructive weather but the vast majority of the flooded areas were simply submerged. This is Mosul



Katrina is an apt comparison given the grossly exaggerated loss of life expectations. On million? Seriously? You would have to drown every resident of Mosul to get that number. The damn holds 2.7 cubic miles of water, do some quick calculations on what the crest will be spread over just the area of Mosul itself.

A disaster? Absolutely. Will this potentially kill many thousands? Probably. A million, certainly not, and you should know better if you are repeating that.

I always value your posts with their clear accuracy, understanding of the engineering of floods and fuck it. The General ignorance in this thread has made me too sad to argue.

Here's the second highest result for flood map mosul. It should answer stuff more clearly then crude volume divided by area.http://www.iwtc.info/2009_pdf/4-1.pdf

[Lord Revan]

With death estimates it helps to know if those are estimates of DIRECT deaths - that is, from the flood waters themselves - or with the addition of knock-on effects.

Knock-on effects are deaths from lack of clean water, from crowd panic, from subsequent fires (yes, it is in fact fairly common for flooded cities to burn, it's happened several times in the US over the past decade or two that I can recall, including in 2008 in my area where a subdivision burned down after it was flooded), and so on. If it happens during extreme weather, or if you get an outbreak of water-borne disease, the casualties can be quite high.

indeed in most disasters a lot if not most of the casualties don't come from the event itself rather from the effects of the aftermath including but not limited to lack of food, clean water and medical supplies.

[Simon_Jester]

Another question is whether that "million dead" figure is based on the population of Mosul directly drowned in the flood, the population of Mosul indirectly killed by massive humanitarian suffering (which Da'esh won't fix and probably won't let anyone else fix), or overall death caused all along the Tigris by large scale flooding and humanitarian crises that the Iraqi government itself will probably fail to resolve very well.

[Patroklos]

The OP article states it could be worse than the 500K estimated because of mass panic and damage further downstream, so it appears they estimate 500K for Mosul due to direct flood causes alone, with the 1M being all told. Which is still ridiculous.

Lets keep in mind that the 2004 tsunami in Thailand caused only (relative) 250K deaths and that was with zero warning, impacting several major population centers the size if Mosul over a far larger geographic area.

[Joun_Lord]

Another question is whether that "million dead" figure is based on the population of Mosul directly drowned in the flood, the population of Mosul indirectly killed by massive humanitarian suffering (which Da'esh won't fix and probably won't let anyone else fix), or overall death caused all along the Tigris by large scale flooding and humanitarian crises that the Iraqi government itself will probably fail to resolve very well.

Its probably just a worst case number based on the estimated population of Mosul where everybody dies rather then any scientific backing behind it. It would possibly be the number of dead if a huge wall of water hits the city with no evacuation or anything. An unlikely but possible scenario.

Most likely a semi-accurate estimation of the death toll would be hard thanks to the unknown population of the city thanks to it being in the hands of dicks who aren't exactly going to be doing a census, lack of any knowledge of possible official response before or after, the unknown state of the dam itself with it possibly breaking 10 seconds from now or next year, the current impossibility of determining how the dam will break (partial failure causing non-catastrophic flooding or full break causing holy god its the 2nd flood why didn't we build an ark holy jesus christ we're doomed), and what international aid could or would be brought to bear on the Mosul region if or rather when the dam breaks thanks to ISIS still being active in the region.

Theoretically if everything goes wrong, if the damn bursts completely and nobody gets out in time, the Red Cross and international aid groups don't come in, ISIS uses the chaos to spread more of their dickery, and the Iraqi government bungles the handling of refugees and clean-up, the death toll could be quite monstrous. Of course even the lower estimates of thousands is pretty bad but certainly nowhere near as bad as a million plus dead.

I wonder if the dam could be slowly drained to try stop a massive blowout? Would probably create some flooding of low lying areas but it would be more gradual rather then some instant thing. I wonder if the sheer amount of water or the state of the dam makes this unfeasible.

[Sea Skimmer]

A non catastrophic break isn't really possible with an earth and clay dam like this having its foundation undermined! if it breaches it will rapidly erode to full collapse. See collapse of the Teton Dam which took only five hours. Two more hours for the flood to hit Mosul. The amount of mud it would leave behind alone would make the city mostly uninhabitable.

Apparently as of March 2nd the contract with the Italians to actually begin repairs on the dam was signed. They will resume grout injections, but probably just as importantly begin construction of a full scale slurry wall to block the infiltration in the first place. Unless that grout wall works the dam is just going to be at constant risk of collapse.

[Simon_Jester]

That's a good thing.

I still have a certain incredulous WHAT at the initial process of how the dam came to be constructed. Great examples of the disadvantages of dictatorship and of strongmen who will listen to whoever promises them the 'best' result regardless of plausibility, as I understand it.

[madd0ct0r]

Another question is whether that "million dead" figure is based on the population of Mosul directly drowned in the flood, the population of Mosul indirectly killed by massive humanitarian suffering (which Da'esh won't fix and probably won't let anyone else fix), or overall death caused all along the Tigris by large scale flooding and humanitarian crises that the Iraqi government itself will probably fail to resolve very well.

Its probably just a worst case number based on the estimated population of Mosul where everybody dies rather then any scientific backing behind it.

Jesus ducking Christ. It's like I totally didn't post a link to the paper these articles are based on two posts above yours.