Abu Dhabi works to ease pressure on groundwater resources with water recycling

Water is a valuable commodity anywhere in the world, but in the Middle East, where temperatures are high most of the year and rainfall rarely exceeds 10cm per year, it is even more precious. In Abu Dhabi, which is mostly hot and arid, natural freshwater is rare and limited to groundwater. However, it is estimated that groundwater – which is used for agricultural irrigation – is currently being extracted at 20 times the natural recharge rate, an unsustainable level.

Conservation

To reduce groundwater use, Abu Dhabi has been promoting the utilisation of recycled wastewater in agriculture and forestry, which account for 95% of total groundwater consumption. In 2017 the Abu Dhabi authorities announced they were targeting recycling and reusing 100% of waste water by 2020. As of 2016 around 51% of treated water was recycled, according to the Environment Agency - Abu Dhabi.

In 2016 the emirate introduced tariffs to encourage more efficient desalinated water use and strengthened laws concerning the illegal use of groundwater. Farmers are now required to install water meters and policing of illegal groundwater wells drilling has been tightened. Under a new law issued in late 2016, the installation of water meters is required at all wellheads and desalination plants to ensure accurate measurements of water extraction. The emirate also increased water tariffs in January 2017 to further discourage water waste and set up a new demand-side management programme, with the aim of reducing water and electricity consumption by 20% through to 2030. Still, water use remains unsustainable in the long term without the use of modern technologies and stronger conservation approaches.

Desalination

Desalinated water is a very important component of Abu Dhabi’s water mix, accounting for an estimated 31% of the emirate’s total water supply and constituting its main source of drinking water. In 2013 the Abu Dhabi Future Energy Company ( Masdar) launched an energy-efficient desalination pilot project, with the aim of demonstrating that seawater desalination technologies could be efficiently powered by renewable energy. In January 2018 the company released its findings, which showed that when used with reverse osmosis technologies, solar power offered a commercially attractive, low-cost and sustainable long-term solution as a power source for desalination plants. The results also revealed that energy efficiency improvements of up to 75% were achieved when compared with existing technologies employed in the UAE.

New Reserve

In January 2018 Abu Dhabi completed works on the world’s largest reservoir of desalinated water, secured in a network of 315 recovery wells up to 80 metres below ground in the Liwa desert. Built at a cost of Dh1.6bn ($435.5m), the reservoir will store 5.6bn gallons of water. The wells are fed by one of the UAE’s longest pipeline networks, which transports water from the Shuweihat desalination plant at a rate of 7m gallons a day and can deliver an emergency pumping capacity of 100m gallons of water a day. “The reservoir acts as a safety net for the provision of water and is now being regarded as an excellent regional model for foresight and planning,” Saif Al Seairi, acting director-general of the Abu Dhabi Water and Electricity Authority, said after the reservoir was completed.

Wastewater Capacity

Another important project is the Strategic Tunnel Enhancement Programme (STEP), a gravity-driven hydraulic wastewater network tunnel being constructed by the Abu Dhabi Sewerage Services Company (ADSSC). The Dh5.6bn ($1.5bn), 41-km project was launched in 2009 and will be one of the longest gravity-driven sewerage tunnels in the world when complete. It is also expected to increase the emirate’s wastewater capacity from around 650,000 cu metres per day to 1.7m and play a significant role in hitting wastewater reuse targets. “The flow capability of STEP is three times current volumes, making it built for the future,” Alan Thomson, former managing director of ADSSC, told OBG in 2017, noting that the main tunnel has been designed with a lifespan of 100 years.