Iraqi engineers involved in building the Mosul dam 30 years ago have warned that the risk of its imminent collapse and the consequent death toll could be even worse than reported.
They pointed out that pressure on the dams compromised structure was building up rapidly as winter snows melted and more water flowed into the reservoir, bringing it up to its maximum capacity, while the sluice gates normally used to relieve that pressure were jammed shut.
The Iraqi engineers also said the failure to replace machinery or assemble a full workforce more than a year after Islamic State temporarily held the dam means that the chasms in the porous rock under the dam were getting bigger and more dangerous every day.
The engineers warned that potential loss of life from a sudden catastrophic collapse of the Mosul dam could be even greater than the 500,000 officially estimated, as they said many people could die in the resulting mass panic, with a 20-metre-high flood wave hitting the city of Mosul and then rolling on down the Tigris valley through Tikrit and Samarra to Baghdad.
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Nasrat Adamo, the dams former chief engineer who spent most of his professional career shoring it up in the face of fundamental flaws in its construction, said that the structure would only survive with round-the-clock work with teams filling in holes in the porous bedrock under the structure, a process known as grouting. But that level of maintenance, dating back to just after the dams construction in 1984, evaporated after the Isis occupation.
We used to have 300 people working 24 hours in three shifts but very few of these workers have come back. There are perhaps 30 people there now, Adamo said in a telephone interview from Sweden, where he works as a consultant.
The machines for grouting have been looted. There is no cement supply. They can do nothing. It is going from bad to worse, and it is urgent. All we can do is hold our hearts.
At the same time as the bedrock is getting weaker and more porous, the water pressure on the dam is building as spring meltwater flows into the reservoir behind it. Giant gates that would normally be used to ease the pressure by allowing water to run through are stuck.
