Schematic of the hydrologic mechanisms that contribute to renewable groundwater in the Al Ain Region (top); and the WEAP implementation of those processes (bottom).

The Water-Energy Nexus (W-E Nexus) constitutes the interconnectivity of water-energy systems, such as energy needed for the desalination, treatment, and transport of water and waste water, and water needed for energy extraction and production. By its nature, the W-E Nexus constitutes a set of interactions, tradeoffs, and system balances among its component pieces, which makes its analysis challenging and not necessarily straightforward. To examine the regional W-E Nexus in the Arabian Peninsula, the project constructed and linked water and energy models (WEAP and LEAP, respectively) in the Arabian Gulf region- specifically Kuwait, Bahrain, Qatar, UAE, Eastern Saudi Arabia and Northern Oman. The coupled water-energy models required detailed data, which were obtained through literature reviews and repeated consultations with key stakeholders in the region. As part of this process the outputs of both models were validated for historic periods using existing data to ensure that the models could adequately represent the systems under investigation.

With the validation verified and the data entry complete, the project deployed the models in simulating future conditions to the year 2060 for five different scenarios. Since the future is uncertain, the models examined two baseline and three policy scenarios of different resource management futures. The baseline scenarios include an investigation of future conditions if current water and energy management practices are kept in place. These are the Business-as-Usual scenarios and include one where the historic climate repeats itself (the BAU scenario) and a second with future climate change conditions based on the United Nation Framework Convention on Climate Change (UNFCC) Representative Concentration Pathway (RCP) 8.5 trajectory adopted by the IPCC for its fifth Assessment Report (AR5) in 2014.

The analysis shows that water needs for the Gulf countries can mostly be met in any scenario through combinations of groundwater, desalination and wastewater reuse, with some regional fossil groundwater basins drawn potentially to extinction by 2060 under the most intensive resource-use scenarios. The scenarios produce different water use for the countries, for example the Integrated Policy Scenario embeds the implementation of all policies and measures that would reduce water demand in the region, resulting in diminishing indoor water use starting in 2020.  Since water provision impacts energy demand (requiring pumping, desalination, and transport), any decreases in water demand will exert similar effects on the energy sector supporting water provision. As groundwater resources are depleted, desalination becomes the main water resource in the region, followed by treated wastewater, which will be limited to amenity and agricultural sectors.

While the analysis includes both a demand oriented scenario (High Efficiency) and a supply oriented scenario (Natural Resource Protection), the results of the analysis strongly suggest that the region will need to simultaneously pursue demand and supply side policies to achieve more sustainable uses of water and energy over the next half century (the Integrated Policy scenario). 

We are developing manuscripts for this regional water energy nexus work to be submitted to the peer review.