T4 dawoud groundwater aquifer storage and recovery in abu dhabi dr. dawoud

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Groundwater Aquifer Storage and Recovery in Arid Regions: Abu Dhabi Pilot Experiment Case

Mohamed A. Dawoud

United Arab Emirates (UAE) as well as other countries in arid region is mainly rely on desalinated water for domestic water supply. The problem facing UAE, however, is the vulnerability of desalination plants to pollution and emergency conditions. Alternatives are required for reserving fresh water sources for emergency and peak demand conditions. Aquifer Storage and Recovery (ASR) techniques have been proposed as a cost-effective large water storage alternative that can help to meet the needs of domestic sector in crisis/emergency situations. In an arid regions like Abu Dhabi Emirate (Figure 1) with no permanent existing natural surface water bodies such rivers and fresh water lakes with limited groundwater resources natural recharge, artificial recharge and storage of surplus desalinated water in aquifers can play a major role in the management of water resources. Due to the absence of large storage reservoirs, desalination plants producing fresh water for urban supply are forced to operate at sub-optimal conditions. Thus, artificial recharge of groundwater and storage of freshwater is deemed necessary and promising technology for meeting seasonal peak demand and offset periods of water deficit due to long-term emergency and natural crisis conditions. Also, it will help to manage seasonal fluctuations in desalination water production and consumption as the production of desalination plants is constant and the demand is not constant. The excess amount of produced desalinated water during the non-peak hours could be stored in aquifers.

Figure 1: Abu Dhabi Emirate Location Map.

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In Abu Dhabi Emirate, pilot ASR project located at west of the highway between Madinat Zayed and Meziyrah was designed for an infiltration capacity of 500 m3/h and recovery capacity of 750 m3/h. A shallow to medium-deep aquifer north of the Liwa Crescent was selected as the study area for the following reasons: (1) existence of a large natural fresh groundwater lens (salinity less than 1,500 mg/l, partly meeting the TDS-limit of the international World Health Organization drinking water standard (1,000 mg/l), (2) sufficient lateral extension and aquifer thickness, (3) sufficient depth of groundwater table, (4) relatively homogenous lithology, (5) far from already existing well fields and (6) favorable hydrochemical conditions. This study has clearly shown that the recharge of desalinated water into groundwater aquifer is an efficient and feasible tool on a large scale for strategic water reserve (Figure 2). Recovery cycles results indicated that under the given conditions the recovery ratios ranged between 85% and 90% were physically recovered. At the end of 250 days lasting period of constant recharge, the lateral migration of the outer injected freshwater body was only 0.2 m/d. For 75 % recovery ratio, the recovered water salinity will be up to 430 mg/l, and for 85 % recovery ratio, the recovered water salinity will be up to 485 mg/l. Both schemes proved to function as designed perfectly. However, in contrast to the infiltration basin scheme, for the dual-purpose wells of the well gallery scheme there are indications of reducing injection and abstraction capacity over time due to clogging effects. Moreover, considering the local hydrogeological conditions, the infiltration basin conception is advantageous as it is easier to operate and maintain. It was recommended to use recharge basin in the full scheme project.

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Figure 2: Groundwater Levels and Flow after 250 days of Constant Recharge.

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after 150 daysInfiltrated Volume: 883,100 m³

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Initial EC of GroundwaterBefore Start of InfiltrationInfiltration Basin

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Natural Groundwater Level

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after 250 daysInfiltrated Volume: 1,482,400 m³


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after 250 daysInfiltrated Volume: 1,482,400 m³


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-225 m -200 m -175 m -150 m -125 m -100 m -75 m -50 m -25 m 0 m 25 m 50 m 75 m 100 m 125 m 150 m 175 m 200 m 225 m

after 25 daysInfiltrated Volume: 149,500 m³Infiltration Basin


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T4 dawoud groundwater aquifer storage and recovery in abu dhabi dr. dawoud