Per capita water consumption of freshwater in the United Arab Emirates is the highest in the world. Over the last several decades, the demand on municipal water supply has increased significantly in the UAE. This is mainly due to increase in population growth, economic development and changes in lifestyle of the people. Though water is used by many sectors such as manufacturing industries, agriculture and domestic purposes, residential and commercial uses of water during the operational phase of the building is one of the biggest contributing factors that puts a strain on freshwater supply in the country.
Desalination and Sustainability
Due to lack of existing freshwater sources in the UAE, limited annual rainfall, high water evaporation rate, the only source of potable water in the region is the desalinated of sea water. The desalinated water contains huge amount of embedded energy due to the process involved in producing it. Apart from energy use, there are many other environmental and socio-economic issues associated with desalinated water. To name a few, there are multiple issues associated with the disposal of brine, salt intrusion, and the high costs of its production. Forecasts show that the demand for desalinated water is expected to double by 2030. Not only the potable water production creates the problem, but also the resulting wastewater generated by the users poses many sustainability challenges such as putting strain on treatment facilities, land and surface water contamination due to overflow of untreated water, disposal of treatment sludge and expensive to production method. Hence, the management of fresh water is considered as one of the most important challenges for the United Arab Emirates.
To deal with freshwater management challenges in UAE, it is important to bring a balance between water supply and demand side. This can be done by employing strategies to increase water efficiency and conservation. These strategies include reduce the use of potable water where possible, find alternative source of water for various water usage and increase the water efficiency of fixtures and equipments. Efficient strategies along with water monitoring that tracks water consumption and identifies problems can significantly reduce both indoor and outdoor water consumption.
Ways to Implement Water Efficiency Strategies
The best way to implement water efficiency in Dubai, Abu Dhabi, Sharjah etc is to develop a comprehensive water strategy at the early stage of project design for both indoor and outdoor water use reduction. The indoor comprehensive water strategy must include the baseline building interior water consumption information based on number of occupants in the building and the flow fixtures and other strategies used. It is required to do calculations for the both baseline water use and projected indoor potable water use based on the fixture and flow rates. The water use reduction targets can be achieved by using water efficient fixtures and appliances and by using recycled water where possible.
To achieve the targets of exterior water use efficiency and reduction, the project team has to develop water reduction strategies for outdoors at the early stage of the design. The strategies should include provision of metering facilities on all exterior water use and provision of easily accessible and clearly labelled water meters that are capable of monitoring water consumption for water uses in heat rejection, external hose bibs, irrigation system, swimming pools, water features etc.
Similarly, at the early stage of design, develop a Landscaping and Irrigation Operation and Maintenance plan. This should contain information on plant species, irrigation strategies to be used and strategies to use recycled water. The low water-use landscaping strategies include carrying out the baseline and design case calculation of building water use, developing a site plan showing the landscape areas, areas of hardscape and softscape along with their irrigation requirements. Strategies to minimise landscaping water demands should be done through appropriate plant selection, irrigations system and recycled water use. Similarly, develop strategies to reduce potable water use for heat rejection and exterior water features.
Use of large volume of water for building operation not only puts strain on municipal water supply and causes negative impacts on the environment but also increases the maintenance and life cycle costs of the building operations. It also increases the consumer’s costs for additional municipal water supply and treatment facilities. Hence, various water efficiency measures can reduce water use in average buildings by 20% or more. Many of the water conservation strategies have no additional cost implication or provide rapid payback while other strategies such as wastewater treatment systems and graywater plumbing system often require substantial investment. The main strategies that should be considered for water use reduction in United Arab Emirates are installation of efficient plumbing fixtures, use of non-potable water, installation of submeters, use of native adaptive plant species, xeriscaping, mulching and efficient irrigation systems.