A model of the Liwa Water Reservoir at ADWEA pavilion.
Abu Dhabi: Abu Dhabi has completed the construction of the world’s largest reserve of high-quality desalinated water, officials announced on Monday during the Abu Dhabi Sustainability Week.
The reservoir, costing Dh 1.6 billion and located in Liwa in Al Dhadra region of Abu Dhabi, has 5.6 billion gallons of water stored in it, which is sufficient to provide one million people in Abu Dhabi with 180 litres per person for up to 90 days, officials said.
Abu Dhabi’s daily water consumption is 980 MIGD (Million Imperial Gallons per Day), Dr Saif Saleh Al Seairi, Acting Director General of Abu Dhabi Water and Electricity Authority (ADWEA), told Gulf News.
Razan Al Mubarak, Secretary General of the Environment Agency-Abu Dhabi (EAD), said the water is secured in a network of 315 recovery wells lying up to 80 metres below the desert.
“Less than 200 km away from Abu Dhabi City, you have this high-quality water reserve in the ancient natural aquifers of dunes in Liwa,” she said.
The water was gradually added over the past 22 months through the UAE’s longest water pipeline networks from Shuweihat desalination plant at a rate of 7 million imperial gallons (approximately 32,000 m3) per day.
Dr Al Seairi said the reserve is connected to the UAE’s water grid and water can be retrieved as and when required. However, the UAE’s water grid is not connected to any neighbouring nation’s water network.
The retrieval rate is faster than feeding. The reserve has unlimited capacity and more water can be fed whenever there is a surplus, he said.
The project, Liwa Strategic Water Reserve, has been completed after more than 15 years of continuous work.
“The reserve acts as a safety net for the provision of water and is now being regarded as an excellent regional model for foresight and planning,” Dr Al Seairi said.
People worked hard in some of the harshest desert conditions and in an environment of a constantly undulating landscape. The project team overcame considerable challenges to complete this one-of-a-kind scheme and lessons learned have been shared with our regional partners, he said.
The project addresses issues of Abu Dhabi’s water security and its resilience through the recharge of groundwater aquifers with high-quality desalinated water, which cannot be stored above ground due to contamination and other factors. The desalinated water is piped from the coast to create the secure, underground reserve system.
Established in one of the world’s driest areas where rainfall rarely exceeds 10 cm a year, the project can deliver a fallback pumping capacity of 100 million gallons of water per day to the emirate if required. The desalinated water percolates into the subsurface through basins with a system of semi-perforated underground pipes to recharge the aquifer using only gravity as a driving force.
The 160-kilometre pipeline from the strategic water reserve site to the Madinat Zayed distribution network in Abu Dhabi city consists of approximately 9,000 sections of welded pipes, some of which measure 1.2 metres in diameter, and are up to 18 metres long. The sections had to be transported into the desert and pieced together through high precision welding, which would take up to five continuous hours per section. A stringent, follow-on X-ray inspection ensured that the system was leak-proof and could withstand the prevailing water pressure for a minimum of 50 years.
Concerns about aquifer contamination from large animals, such as roaming camels, were addressed by working with nature, which resulted in the creation of a ‘groundwater protection buffer zone’ made from locally produced palm-frond while solar panels power wellhead monitoring instrumentation.
Source: ADWEA and EAD