GCC steps up efforts to conserve water
As a water crisis looms large in the GCC, the UAE has launched the world’s largest underground reserve for desalinated water. Could groundwater recharging unlock new possibilities for water security in the region?
Nearly six decades ago, the United Arab Emirates (UAE) had a total population of about 90,000 people. Today, the country has 100 times as many inhabitants. And despite having less than 1% of the world’s available water supply, the UAE is home to the highest consumers of water in the world.
Daily per capita water consumption averages 500 litres, about 82% above the global average. The government, along with water solutions providers and water researchers have been trying to instigating a balance between innovation and regulation to address a looming water crisis in the region.
While the UAE has over the past few years adopted a strategy that aims to expand its total seawater desalination capacity by nearly 40% by 2020 in an effort to meet the rapidly increasing demand for potable water in the region, water security remains a major concern.
At the launch of the 2018 International Water Summit in Abu Dhabi, the UAE took a big, bold step to ensure water security for its residents. The Abu Dhabi Water & Electricity Authority unveiled the world’s largest reserve of artificially desalinated water.
The reserve exists in an aquifer under the Liwa desert at the southern edge of the country, about 160 km away from the desalination plants located at the coast. It contains about 26 billion litres of water, and needed 26 months to fill it up. In case of emergencies, the reserve can provide about 100 million litres of water per day to the country’s residents in a region where rainfall rarely exceeds 10cms a year.
The water that the reserve can provide each day is only a fraction of the country’s 6 billion litres of daily consumption. That’s because the total consumption includes uses beyond the bare necessities, such as watering the country’s many golf courses, running its indoor shark pools, and huge entertainment parks.
While GCC communities have for centuries relied on groundwater for their water needs, research by the Environment Agency Abu Dhabi (EAD) notes that the emirate’s groundwater supplies will run out within 50 years.
Water extraction has now exceeded the natural recharge capacity which has led to the deterioration of water quality and a dramatic drop in the water table.
This has meant that the groundwater main areas are not in compliance with the existing potable or industrial water guidelines and standards. They are not suitable anymore to be used for domestic, industrial or commercial applications.
The planning to build the Liwa underground reserve began in 2002, and it cost about $450mn. This includes drilling costs and construction of a system of water pipelines, but does not include the cost of the water that will be used to recharge the aquifer. The reserve, which has at its core an infiltration and recovery system sitting atop a natural fresh water underground aquifer has been extensively researched by EAD.
The project was undertaken as a collaborative venture between EAD, delivering the vital scientific studies, feasibility, risk and mitigation scenarios as well as strategic planning Abu Dhabi Water and Electricity Authority (ADWEA) and its TRANSCO subsidiary, which managed the construction and on-the-ground implementation.
Other project partners included Regulations and Supervisions Bureau (RSB), the independent regulatory body for Abu Dhabi’s water and electricity sector, GIZ International, Do. Rainer Consultancy and ACC-POSCO JV.
The wells are fed by one of the UAE’s longest water pipeline networks which runs the water from Shuweihat desalination plant at a rate of 7 million imperial gallons (approx. 32,000 m3) / day over 27 months.
The desalinated water is transported through large pipes, about 1 meter in diameter, which had to be pieced together in the desert through high-precision welding to make them leak-proof for at least 50 years. The water is then dumped about 80 meters underground through perforated pipes, where it seeps deeper into the aquifer. There are about 300 wells to recharge, recover, and observe the aquifer’s water.
“Desalination plants can be shut down by storms, a malfunction, a random sea raft, and even the red-tide phenomenon which has been exacerbated by climate change,” says Saif Saleh Al Seairi, who heads Abu Dhabi Water and Electricity Authority (ADWEA).
“The government realised the need for an alternative supply to cover our needs [and] also mitigate against climate risks.”
The project is expected to address Abu Dhabi’s water security through the recharge of groundwater aquifers with high-quality desalinated water, which cannot be stored above ground due to fear of contamination and other factors.
At present, Abu Dhabi derives 65% of its water from the ground, 29% from desalination and 7% from re-used water. Reserve supplies of water for residents in Abu Dhabi will increase from about three days to up to 90 days at full capacity.
Al Seairi says that lessons learned in building the reserve will be shared with “regional partners.” These lessons are likely to help make the next such project slightly cheaper. The project is expected to be replicated in neighbouring GCC countries that are equally in need of water.
“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,” says Al Seairi.
The project is the first of a series of planned underground water storage facilities across the Emirate that are expected to store fresh water up to 100 years. Work is expected to start on a second reservoir, which will be built in Al Ain area, thus having both the eastern and the western regions of the emirate covered in case of an emergency.
“The recharge of groundwater with large volumes of desalinated seawater is a new approach, and to our knowledge nowhere else conducted on an industrial scale at present,” says an engineer who worked on the project.
“The project offers the unique opportunity to develop a reliable and sustainable large-scale fresh groundwater reservoir in a desert region utilisable whenever needed.
“It is considered a milestone for securing the water supply of the emirate of Abu Dhabi for the indefinite future. Once implemented, this project will represent a benchmark for water management in desert regions, capable of redefining international standards.”
In the past, rainwater was sufficient to recharge these underground aquifers, but with increased human activity, along with prolonged rain scarcities, water extraction has endlessly outpaced the recharge rate.
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 project ensures continuous water supply for Abu Dhabi city and Al Dhafra region and secures the reserve for future generations. Whenever needed, water from the 315 wells, lying up to 80 metres below ground, can be used to recover supplies at any time.
The reserve now holds more than 26 million m3 of water (equivalent to 5.6 billion imperial gallons) that can bolster drinking water supply when needed.
“The long-term wellbeing of our communities is significantly enhanced by the maintenance and enhancement of groundwater while being conscious that we need to progress additional recharge and recovery projects to optimize flexible allocation of water as required,” says Razan Khalifa Al Mubarak, Secretary General, EAD.
“This is therefore a breakthrough sustainable engineering feat. The Liwa reserve indicates our commitment to modern scientific knowledge and Abu Dhabi’s future vision for a balanced approach between development and conservation.”
Al Mubarak says that throughout the implementation of the project, considerable attention was paid to the use of highly engineered, environment-friendly specification materials, which were deemed appropriate to the Liwa area.
The infiltration basin was insulated with protective materials, including a gravel mix of large pore stones to evenly distribute water and ensure better filtration.
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 with stringent, follow-on X-ray inspection to ensure the system was leak-proof and could withstand the prevailing water pressure for a minimum of 50 years.
He says that widespread concerns about aquifer contamination from large animals, such as roaming camels, were prudently 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.
The Liwa desert was chosen for the project after it met strict specification criteria. These included an extremely light water basin trajectory to prevent leakage; capable of sustaining a ‘tank’ thickness to handle significant storage volumes; safe surroundings free of human activities which could contaminate the reserve and where groundwater quality was of sufficient quality to allow for ‘recharge and mixing.’
“We decided to recharge the depleting ground aquifers with our surplus desalinated water and the result proved to be the most efficient way to store water at the lowest cost,” says Al Seairi. “We do not need to build and maintain water tanks. We do not need energy to power their injection. What we need to do is only re-inject water to replenish and restore what was previously there.”
Water quality is ensured through strict control, heat and salinity monitoring equipment and a range of other metrics. “Running the expansive well network simultaneously is a complex process. Communication and inter-team information exchange is critical,” Al Seairi points out.
“All this data is connected to a master network that acts as the project’s ‘brain’ and is housed in a state-of-the-art electronic process centre from which technicians control pumps, wells and valves and water quality which complies with RSB drinking water standards, is ensured by automatically operating at least 20 wells per day.”
The strategic water reserve project will be operated, managed and maintained by TRANSCO with scientific support by EAD. In readiness for the operation period, TRANSCO has prioritised the training of UAE nationals as project managers.
“Their contact with this project vastly increases their experience, enriching their national pride and their sense of this project’s value and they add their insight and viewpoint to achieve the project’s objectives,” says Mohammed Bin Omair Al Shamsi, Chairman of the Board, TRANSCO.
According to EAD, the project is a visionary undertaking that will eventually help to address the pressing water needs in the region.
“For several generations, the storage of huge reserves of fresh water in the desert was considered unfeasible,” says Al Mubarak. “This achievement is a result of great vision, innovation and wise investment in technology and expertise.”
Al Mubarak adds that through inter-agency co-operation, EAD has adopted a coherent approach to create real change in the management of water resources to ensure the protection of the environment to guarantee economic prosperity.
“The GCC needs a good and long-lasting back-up plan for emergency situations,” says Dr. Mohamed Abdel Hamyd Dawoud, water resource department manager at EAD. “We want to be prepared for things that could lead to water shortages such as pollution, oil spills and natural disasters.”
While some GCC countries such as Saudi Arabia have chosen to build a collection of water reservoirs in preparation for as part of their water security strategies, several studies consider this approach economically and environmentally unsuitable.
“To store five billion gallons of water, enough for emergencies only for 90 days, we would need to build 2,000 reservoirs. Apart from the expense, imagine how much land it would be needed,” says Dr. Dawoud.
“Also, in reservoirs water is stagnant and opened to air pollution, so after five to seven days it would need changing. In aquifers, water can be stored up to 100 years.”
Aquifers are also considered the best option because they are less expensive, better for the environment and less exposed to potential security threats than a vast installation of above-ground tanks would be. Surface ponds and lakes lose water to evaporation and are susceptible to micro-organisms and pollution.
“Water tanks are about 10 times more costly. But the underground system is a viable option only if most of the costly water originally deposited can be retrieved - and immediately,” says Mohsen Sherif, a professor of water resources and the chairman of the civil and environmental engineering department at UAE University.
“As long as the area surrounding the aquifer is protected against pollutants, the system will be efficient because a high percentage of the recharged water can be pumped out again, and it is expected to be of the same high quality.”
Hassan Fath, a professor of practice and water and environmental engineering at Masdar Institute says that storing water underground is best to protect it against bacteria.
“It’s very serious and important to consider how people will suffer if, for any reason, the country’s water desalination plan is blocked for even more than a few days,” says Fath. “Like any well, this is going to be well-preserved and well-sealed. It is really the best solution.”
The World Bank has reported that fresh water scarcity could be the biggest problem facing the economies of the world. Economies across large portions of the planet could shrink dramatically by 2050 as climate change causes fresh water scarcity issues.
“A few regions may suffer particularly badly. One standout is the Middle East, where gross domestic products (GDP) could slip by as much as 14% unless the region comes up with ways to significantly reallocate the supply of fresh water,” says Richard Damania, Global Lead Economist in the World Bank’s Water Practice says of the situation.
He says that achieving this would require improved efficiency standards, investments in technologies to produce greater quantities of fresh water such as desalination plants, and means of recycling water.
The GCC has recently intensified studies and pilot projects aimed at recharging existing aquifers to provide a backup to desalination, as opposed to investing heavily on building underground water reservoirs due to the disadvantages associated with them.