ADWEA awards world's largest water storage project
ACC and POSCO win US$436m EPC contract in Abu Dhabi
The Abu Dhabi Water and Electricity Authority (ADWEA) and the Environment Agency have awarded a US$436 million contract for the engineering, procurement and construction (EPC) of the world’s largest strategic water project to a joint venture between Arabian Construction Co (ACC) and POSCO Engineering & Construction Co (POSCO).
Once completed, the Strategic Water Storage and Recovery System, to be built in Liwa, 250 kilometres of Abu Dhabi City, will be able to store 26 million cubic metres of desalinated water in the ground, according to Peter Menche, director or projects at GTZ, a German governmental organisation that plays an advisory role in the project.
Of these, 16.3 million cubic litres can be recovered as potable water, enough to supply each Abu Dhabi resident with 182 litres of water over a three months period.
Work on the project will commence in September, and will take approximately 30 months to complete.
“This is the world’s largest project of its kind, and the fact that it is executed in the harsh desert terrain and will make use of desalinated water mean that this is very much a landmark for the region,” said Menche.
“The government's goal is to be able to supply the city with 40 million imperial gallons of water per day (MIGD) for up to 90 days in the unfortunate event of a water emergency,” adds Wassim Merhebi, director at ACC.
The system is based on an infiltration basin/recovery well system known as aquifer storage and recovery. From these basins, the water is filtered down to 85 metres below ground. A total of three basins will be constructed and filled with gravel and topped with a ‘geotextile’ cover over a period of 30 months. The cover will prevent evaporation and contamination. When completed, the five meter deep basins will allow water to seep into the groundwater via PVC pipes.
The system features water pipe lines, HV transmission lines, pump stations and a SCADA system. In the event of a water emergency, all water stored at the facility can be made available for pumping to Abu Dhabi City through a system of pumping stations and 161km of new pipeline that will connect to an existing pipeline system situated along the E11 highway.
While concept of artificially bolstering groundwater levels is not new, the scale of the project is unprecedented.
The water storage capacity of the scheme can be expanded in future, says Menche, provided extra water basins are constructed. Abu Dhabi’s population is expected to increase to 3,1 million by 2030 according to GTZ estimates.