Friday, January 1, 2016

ISIL isn't all Iraq has to worry about

I was surprised to read of a disaster waiting to happen on the Tigris River in Iraq.

A lethal threat sits in Iraq right now, one that could kill hundreds of thousands of civilians with little notice. The weapon briefly fell into the jihadis’ hands last summer, and still poses a destructive risk to much of the country.

The 750-megawatt Mosul Dam is the country’s largest, and one of the most productive in the Middle East. But its proximity to Mosul, ISIS’s biggest Iraqi city, has caused nightmares in both Baghdad and Washington.

Built during the Saddam era on a weak foundation of gypsum, the dam requires continuous maintenance and reinforcement with fresh concrete. Without these efforts, some ten billion tons of water threaten to sweep down the Tigris, flooding towns and villages hundreds of miles downriver. Baghdad could see flooding of more than fifteen feet, according to one report. A U.S. Army Corps of Engineers study in 2006 called it “the most dangerous dam in the world” and estimates of the potential civilian death toll reach as many as half a million.

There's more at the link.

Mosul Dam (image courtesy of Wikipedia)

I couldn't figure out why any dam would be built to such shoddy specifications, or how it could 'require continuous maintenance and reinforcement'.  Further investigation revealed:

Construction on the Mosul Dam began in 1980 by a German-Italian consortium that was led by Hochtief Aktiengesellschaft. Because the dam was constructed on a foundation of soluble gypsum, the engineers recommended the implementation grout curtain within the foundation before the superstructure was built. Instead, to speed construction of the dam, engineers installed a grouting gallery that would allow continuous grouting of the dam's foundation in order to promote stability. Construction was complete in 1984 and in the spring of 1985, the Mosul Dam began to inundate the Tigris River, filling the reservoir which submerged many archaeological sites in the region. Because of significant structural stability issues associated with the Mosul Dam, grouting and additional construction and repairs are constant.

The earthen embankment dam is located on top of gypsum, a soft mineral which dissolves in contact with water. Continuous maintenance is required to plug, or "grout", new leaks with a liquefied slurry of cement and other additives. More than 50,000 tonnes (49,000 long tons; 55,000 short tons) of material have been injected into the dam since leaks began forming shortly after the reservoir was filled in 1986, and 24 machines currently continuously pump grout into the dam base.

. . .

Iraqi officials maintain that the U.S. government is overstating the risk. The Army Corps of Engineers has proposed that the Badush Dam under construction downstream be expanded to obstruct the large wave which would result if the Mosul Dam collapsed. This has been resisted by Iraqi officials, who note that the current plan for the Badush Dam is US$300 million to provide hydroelectric power and help irrigation while the proposed expansion would cost $10 billion.

Again, more at the link.

So Saddam Hussein built a dam on a soluble foundation, not a solid one;  and it's basically been under repair ever since, to stop Mother Nature doing what she does so well and punishing human hubris by bringing inevitable nemesis.  All this in a country where the USA has spent, by some accounts, as much as $60 billion in US currency and $146 billion in Iraqi currency on rebuilding its infrastructure.  A mere one to two per cent of that money would have sufficed to completely rebuild this dam (or replace it with one in a more suitable location) and make sure it wouldn't need ongoing maintenance, or fall prey to natural decay.  Seems to me that would have been a much better way to spend it than allow so many billions to be frittered away on graft, corruption and sleaze.



Tom Stedham said...

I agree completely.

Anonymous said...

Any dam that requires a lot of grout injection has a high risk of being a mess. The Teton Dam in the US is probably the most (in)famous, but I can think of a few others that were close-run at least once during their construction or shortly after. Engineers really, really don't like to hear phrases like, "It's taking a lot more grout than we anticipated," or "Hey, boss, we found a bunch of voids in the canyon wall."


Uncle Lar said...

But Peter, graft, corruption, and sleaze are the life blood of the sort of politicians and the crony capitalist contractors supplying the labor and materials. If they'd built the dam right in the first place all the continuing largess would be diminished or entirely cut off. Can't be having that now can we.

Fred said...

Baghdad was a cosmopolitan city. Saddam was a strongman to sure but Shiites, Christians, kurds and others were all living and working side by side in what was quickly becoming a modern international state. Now Christians are being slaughtered, a vile Wahhabi sect is killing everyone that disagrees with killing everyone that disagrees, and the infrastructure that we didn't "bomb back to the stone age" is rapidly decaying. Glad we could help.

Anonymous said...

This doesn't even address what might be deliberately done to it if ISIL decides they are going to lose the area.


A.B. Prosper said...

Anyone with any sense would expect massive grasp in a low trust, clan based society like Iraq.

Its not like the US isn't nearly as bad.

A perfect example, the US could have easily paid for better than NHS level health care for every American or fixed the worst the entire US infrastructure for what we spent on the F35 a jet that doesn't appear to work very well and is designed for fighting the last war.

Inconsiderate Bastard said...

Barnes Wallis is no longer with us, but the plans are still around and he probably has grandchildren.....

Stu Garfath, Sydney, OZ. said...

All isis have to do is turn off the grout pumps, destroy any ease of access, fight a rearguard action - joking here, and leave town, job done.

Douglas2 said...

A.B. Prosper:
Government spending on healthcare in the US was $3893 per capita for fiscal year 2014.
Government spending on the NHS in the UK was £1,994 per capita for 2013/14
At the peak value of the pound against the dollar during that time period the US was still up about $400 against the UK on per-capita healthcare spending
Total cost of the F35 program over the projected life of the aircraft is what, about $90 per capita?

Douglas2 said...

per capita per annum, that is. Apples to apples and all that...

SJ said...

One thing I don't expensive/complex is it to take a dam down, and build it better?

Without drowning everyone downstream, that is.

Anonymous said...

SJ, I'm not an engineer, just a historian of water supply systems, but I'd say at that sort of location it is pretty expensive. Depending on where you want the new dam, you'd need to empty the reservoir and let the sediment dry a little at the dam-site, construct a cofferdam to divert the water around the construction, excavate down to bedrock or at least until you reach a less permeable layer, start building your foundation, and go from there. If you build it at a site downstream of the original you could probably use the old dam as your temporary diversion, but its still going to be a challenge, and it will seriously disrupt water usage and flow control downstream no matter what you do. If you could look at the original geological studies, I suspect the current structure is in the least-bad of the various options that were available.