Epistemic status: Shallow cause investigation, 10-20 hours of research/thought distributed lumpily into 2 main periods over 4-5 years. Bat signal, not rigorous.
Acknowledgements: Thank you to Kathy Forth for starting this investigation. She started the draft for a post on this and then handed the project off to me. All mistakes are mine.
Update - There's some evidence the Iraq government plans to implement one of the permanent fixes? Big if true. See my comment here.
tl;dr - There is a dam 60km north of Mosul city in Iraq that is at chronic risk of collapse. Some call it "The World's Most Dangerous Dam".
It was built in the 1980s under the Saddam regime on sediment that contains gypsum deposits, which erode due to the water, creating growing holes under the dam. This requires continuous 'grouting', which is filling in the holes with cement and stuff. This is a temporary solution since 1986. One of the dam's lead engineers has been the lead advocate for dealing with the problem. The Iraq government has not been adequately addressing it. Simulations suggest 500,000 to 1.5 million people could die just from the flooding down the Tigris river all the way to Baghdad, not including famine and a lack of international emergency access due to flooded airports.
Toy Expected Value Calculation: One solution would be to spend $2 billion to finish construction of Badush dam downstream in order to block the floodwaters, which if this saved 1 million lives would come out at $2000/life saved, better than AMF. Even if that's likely too optimistic, it's suggestive, as the likely if as yet unknown existence of more targeted marginal uses of money for readers means this is in my opinion a very promising new cause area worth further investigation, this post being an opener towards further inquiry. I encourage others to do much more detailed expected value calculations, with openminded curiosity.
Operational Status: I am posting this now and might update it after posting because I am encouraged by the spirit of what FTX is currently doing and will submit it to their ideas competition. I am also working on other important stuff and don't have the attention to optimize this. I would love it if someone who's not me could take up being a cause champion and spend some time investigating whether this is worth it as a potential EA megaproject. If we could spend $1 million to get governments to spend $1 billion to fix it to save 1 million lives (or something like those orders of magnitude), that would be highly valuable!
From Wikipedia:
A September 2006 report by the United States Army Corps of Engineers noted, "In terms of internal erosion potential of the foundation, Mosul Dam is the most dangerous dam in the world." The report further outlined a worst-case scenario, in which a sudden collapse of the dam would flood Mosul under 65 feet (20 m) of water and Baghdad, a city of 7 million, to 15 feet (4.6 m), with an estimated death toll of 500,000.[17] A report on 30 October 2007 by the US Special Inspector General for Iraq Reconstruction (SIGIR) said that the dam's foundations could give way at any moment.[18]
According to The Economist, "One study says that if the dam collapses, Mosul would be submerged within hours. Another warns that half a million Iraqis could be killed by floodwaters, and more than a million forced from their homes. Disease and looting as the floodwaters raced through Baiji, Tikrit, Samarra, and even parts of Baghdad would complete that dreadful scenario."[19] Nadhir al-Ansari, an engineer involved in the building of the dam who is currently Professor of Engineering at the Luleå University of Technology, Sweden, said that the floodwaters would take four hours to reach Mosul and 45 hours to reach Baghdad, and that more than a million people would be killed if a "good evacuation plan" were not in place.[20]
In 2004, dam manager Abdulkhalik Thanoon Ayoub ordered the dam's water level, which can reach 330 metres (1,083 ft) above sea level, to have a maximum of 319 metres (1,047 ft), thus reducing the pressure on the structure. Nevertheless, Iraqi officials maintain that the U.S. government is overstating the risk. The Army Corps of Engineers has proposed that the Badush Dam downstream be completed to serve its purpose of obstructing the large wave that 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.[17]
In 2007, the U.S. Army Corps of Engineers developed and executed a US$27 million plan to help continue maintenance and repairs on the dam in the short-term. The Iraq Government was also recommended a long-term solution that includes the construction of 67 m (220 ft) deep walls around the dam foundation. The project would cost $4 billion and take approximately four to five years to complete.
If you want to learn more I highly recommend the New Yorker piece, "A Bigger Problem Than ISIS", which is the most in-depth reporting on the topic.
There's more links in a list below.
According to a report by Ansari and Adamo, permanent solutions are:
1. Install Diaphragm Wall through the Mosul Dam which should extend deep
into the foundation below the lowest gypsum/anhydrites (GB0) layer. Such
solution has never been used in the world before in a dam site (250m depth).
Comprehensive evaluation, testing, and geotechnical assessment will be required
to prove the viability and effectiveness of this method for Mosul Dam. Such
diaphragm will be the deepest in the world and it will introduce risks associated
with the required depth and complex foundation conditions. In addition, there
would be complex issues associated with contact with bottom outlets and power
tunnels and the length and depth of the Diaphragm Wall in both the left and right
abutments, particularly the left abutment where the Diaphragm Wall may need to
extend for kilometers beyond the spillway, saddle dam, and fuse plug. The
extension in the right side must also be studied carefully taking into consideration
the results of the hydrological numerical model that was done previously. Total
cost must be given considerable considerations. Although it may be possible to
construct the diaphragm wall, it may not fully solve the problems with Mosul
Dam.
2. Complete Construction of Badush Dam- The downstream Badush Dam could
potentially be completed to prevent widespread disaster from the failure of Mosul
Dam. It is understood that Badush Dam was 30-40 percent complete when
construction was stopped in the late 1990’s. Because of question about the
foundation of Badush Dam, this issue should be considered and the likelihood of
gypsum and anhydrite at depth beneath the dam should be considered in the
evaluation. It is likely that the design of Badush Dam should be modified before
construction begins with consideration of diaphragm wall and other design
changes, the cost to construct the Badush Dam would need to be revised
accordingly.
3.” Hybrid Approach” – The safest alternative may be a “hybrid” approach with
utilization of both Mosul Dam and Badush Dam for a period of time, transitioning
the Badush Dam serving as the long term solution. For example, the Badush Dam
could serve for a period of time as a back up in the event of failure of Mosul Dam.
This would essentially mean that the Badush Dam reservoir stays nearly empty for
this period of time to allow enough storage to retain the Mosul reservoir if the
Mosul Dam fails. This would allow the Al Jazera and other irrigation and water
supply systems to rebuild for change in water elevations. Not waiting for failure of
Mosul Dam to fill Badush Dam reservoir and the ensuing issues and risks that
would result, Badush Dam could be completed and the Mosul Reservoir could be
released into Badush Reservoir in a controlled manner. Following that, Mosul
Dam could be decommissioned with an engineered breach to allow the new
Badush Dam to hold the new reservoir.
A diaphragm wall would purportedly cost $3 billion, and completing Badush dam would cost anywhere between $2-10 billion.
There are likely/definitely other (marginal) solutions that could be more cost-effective from a marginal effective altruist perspective.
I don't know what a tractable push here on our part would look like besides two main areas I would guess:
- Doing advocacy/lobbying governments or other large actors to fund a permanent solution. This is likely fragile, possibly totally unrealistic, but if someone investigated it we could determine if it's viable.
- Incrementalist solutions such as improving evacuation capability, emergency food stocks, etc. Maybe we could save 10% of lives in case it collapses using a small amount of our resources (and maybe that could be part of an advocacy push too)?
Links/Resources/Quotes
- Videos
- Research
- European Commission JRC Technical Report: Impact of flood by a possible failure of Mosul Dam (link to direct PDF download)
- "In this study we perform a number of medium-resolution (180m) dynamic hydraulic simulations starting from various constant percentages of destruction of the dam and allowing the corresponding quantity of water (supposing the lake to be at its highest level) to flow downslope for periods of 6 and 12 days. Compared to previous studies we provide in addition a complete timescale of the water flow progression, detailed maps of the water depth and extent in the affected cities’ areas and focus more on the numbers of population affected by various water depths. The main scenario analysed in this study, where the dam is 26% destroyed, the level of the lake is at its maximum value of 330m, and most of the lake’s water is allowed to flow out fast, results in a very high wave of water (in places 25m high, mean height around 12m) arriving at Mosul city after 1h40min. The capital Baghdad is reached after about 3.5 days with a max water height of 8m and a mean of around 2m. The simulations suggest that in the above scenario a total of more than 6 million people (close to one sixth of the country’s population) will be affected by floodwaters, with two million of them facing water of more than 2m. Water heights of more than 10m would inundate an area with 270 000 people, most of them in Mosul city and its surroundings, whose lives, houses and infrastructure would risk complete destruction."
- Mosul Dam Full Story: Safety Evaluations of Mosul Dam
- "Mosul Dam is the second biggest dam in the Middle East due to the capacity of its reservoir. Since the operation of this dam in 1986, it is suffering from seepage problems in the foundation of the dam due to the dissolution of gypsum and anhydrite layers under the foundation. This phenomenon has raised concern about the safety of the dam. Studies done during the recent years showed that grouting works can only be considered as a temporary solution at its best. It is clear now that while grouting must be continued search for long term solution must be sought if dam failure consequences are to be avoided. This must be done as soon as possible as the dam is showing more and more signs of weakness. It is further considered that the suggestions and recommendations forwarded by the team of Lulea University of Technology and the Panel of Experts in the Stockholm Workshop 24-25 May, 2016 give the most practical and suitable solutions for this problem."
- Mystery of Mosul Dam: The Most Dangerous Dam in the World
- The Mosul Dam: Turning a Potential Disaster into a Win-Win Solution
- Geological and Engineering Investigations of the Most Dangerous Dam in the World
- SIGIR Report: Relief and Reconstruction Funded Work at Mosul Dam
- US Army Corps of Engineers: Geologic Setting of Mosul Dam and Its Engineering Implications
- Journalism
- Mosul Dam - Wikipedia
Key Actors (List is unfinished, I'm just getting it out there)
- Nadhir al-Ansari, professor of water resources and environmental engineering at Lulea University in Sweden and a published expert on the Mosul Dam
- Foremost advocate for the issue in media
- Email: [email protected]
- Phone: +46 (0)920 491858
- Lulea University Research Team, led by Nadhir al-Ansari
- Analyzed all data and came up with solutions
- Nasrat Adamo, former chief engineer of Mosul Dam (contact)
- PAFI
- Peace Ambassadors for Iraq. They convened a symposium about the issue.
- Update 2022: I think they're defunct. Their website looks hacked.
- Issa
- Azzam Alwash
- Researcher and environmentalist.
- TREVI
- Italian company fixing the dam right now.
- Dexter Filkins, New Yorker journalist
- Really good article on it, would know more.
- Iraq’s Water Resources Ministry
- U.S. Army Corps of Engineers
- U.S. Embassy
- ?
- ??
- ???
This is an interesting issue; it makes sense that ISIS would be bad at dam maintenance.
Without reading all the sources (so perhaps these are clearly answered somewhere in there), some next questions I'd be curious about:
I appreciate that this is just a toy estimate. But I think even at a toy level we could make the estimate more accurate by having a term for "P(dam failure within X years, absent our intervention)". The dam may not fail within a given timeframe, or it may be fixed by other actors before it fails, etc, and it doesn't seem like the case is so overwhelming that these outcomes should be ignored. E.g. if you think the dam is 50% likely to fail within 40 years, absent our intervention, then the estimate looks like $4000/life saved in expectation.
I agree that's important, and would like to add a section for that. I did not find any actual quantitative estimates of the risk, and now think that one initial step here would be for someone to comb the research more thoroughly than I did, or survey some engineers either involved or not, or outright commission someone to model the risk of the dam.
I don't know if other actors will fix it, though they haven't so far in 35 years, including when the U.S. occupied Iraq.
My qualitative sense of the risk is, "This will eventually collapse at some point if nothing permanent is done beyond indefinite grouting work, which has some amount of imperfection, and no one is doing the permanent fix."
I think this means that since the damage is cumulative, there could be some predictability to it. Probability would only increase over time. Maybe if a detailed enough simulation were done, we could get a better sense of it.
That means I would maybe put 20% on it collapsing by 2040, and maybe 60% by 2060 (without additional intervention).
I don't know what the likelihood of outside intervention is, but I wouldn't put it at greater than half over the next 20 years. So that puts my personal ballpark at 10% chance of collapse in the next 20 years.
We also have to include the risk of Great Power War or something else more disruptive than ISIS occupation halting the grouting work.
I would be rather worried about rough outside view calculations preventing someone from engaging with this who would have. Far better to form a physical model of what's happening with the dam, if someone can do that (I was disappointed to see none of that IIRC with my Three Gorges Dam question). We could also model who are the likely individuals to fund a fix, talk to them to see if they have plans for that, and try to influence them, at pretty low cost.
Could you please provide a source for the "500,000 to 1.5 million" deaths estimate?
Summaries and pointers to some primary sources can be found on the Wikipedia page I linked, which at a high-level answers these questions:
If people have questions about the estimates, I recommend directly contacting and asking the authors of primary sources, if they're available (and letting us know what you learn). I will add this Wikipedia information into the post for legibility.
None of those studies mention 1.5 million deaths. One of the studies estimating 500,000 deaths is cited as outlining a worst-case scenario. The most pessimistic estimate of 1 million deaths is conditional on no good evacuation plan being in place. More importantly, all of these studies were based on the dam's condition before extensive repairs were carried out in 2016–2017—repairs that were undertaken to address just those safety concerns. As the Wikipedia article notes, "In May 2017, Iraqi Minister of Water Resources Hassan Janabi stated that no danger to the dam remained and it was going back to normal operation. Carlo Crippa, the project manager, said the dam structure now showed no significant signs of distress."