ABU DHABI // The emirate plans to pump billions of gallons of fresh water underground to establish an emergency reserve. The Dh1 billion (US$270 million) project would supply Abu Dhabi with drinking water for three months should other sources fail.
The water would be stored in artificial aquifers, layers of water-bearing rock or sand from which reserves could be drawn through wells. Dr Mohammed Dawoud, manager of water resources for the Environment Agency Abu Dhabi, said more than five billion gallons of desalinated water would be pumped underground, at a rate of five million gallons a day for three years. "In Abu Dhabi and the Gulf region we rely on water from desalination plants for domestic use; we have no surface water and we have no groundwater to speak of," he said.
"Desalination plants are very sensitive to any pollution in the Gulf or any other kind of emergency. They also sometimes need to be shut down for several weeks for maintenance. Because there are no complementary resources, we need to have a strategic reserve." The aquifer scheme was approved in March after a successful pilot project near Liwa in 2004. Work on the main strategic reserve is expected to start by the end of next year, with water injection starting in 2011.
Dr Dawoud said three options had been considered: borrowing water from neighbours, storing water in tanks and using the sand and rocks of the desert to trap the water in aquifers. "In this region, pumping water from neighbouring countries is not an option as they are in the same situation as us," he said. "We could look at building storage tanks out of steel and concrete, but that would cost a lot of money and would have a huge environmental impact, as they would require a lot of land.
"There is also the problem that if the water stayed in the reservoir for more than 48 hours, it would have to be treated with chlorine and other chemicals, or replaced, or it would become stagnant and algae would start to grow." He said creating an underground aquifer would not only have little impact on the environment, but would also keep the water in a usable state. "It will be available and protected underground, where it can stay for years without stagnating," Dr Dawoud said.
"We will also lose very little water. If you pump in 100 cubic metres of water, you will get an average of 80 cubic metres back that can be used for drinking, while the other 20 per cent can be used for agriculture and other things." He said the pilot scheme had produced "very good results" while similar projects had proved successful in the United States and Europe. "So we are very satisfied that this is the right course of action," Dr Dawoud said.
"We have identified a number of areas, starting with Liwa, where the geological conditions are right for a project of this kind to work. "You need to have somewhere with the right kind of rocks, but where there is also a low level of existing saturation from groundwater. The water we will be injecting will require some treatment when it is recovered, but essentially it is fit for humans to drink. What we don't want is to inject it in to a place where there is already saline or otherwise contaminated water that will mix with the fresh supply."
He said the Environment Agency Abu Dhabi was determining what facilities were needed to create and maintain the reserve, with companies likely to be invited to bid for construction and other work next year. "We should be ready to start injecting water by 2011," Dr Dawoud said. "Assuming we have no problems, we aim to create more reserves elsewhere in the country. This is an essential project." @Email:firstname.lastname@example.org