Towards a more sustainable water management scheme for Qatar

Abstract

Qatar is an arid country with limited natural freshwater resources due to low rainfall and high evapotranspiration. The country, having the third largest natural gas reserve in the world, relies primarily on fossil fuel-powered seawater desalination to meet domestic water demand, estimated at around 600 liters per capita per day. Additionally, groundwater is being depleted to supply the agricultural sector, which consumes about 230 million cubic meters of freshwater each year. Hence, this paper aimed at improving the sustainability of the water management scheme of Qatar by developing a combination of water demand and water supply management strategies. On the demand side, the impacts of higher water tariffs and greywater reuse on domestic water demand were studied independently relative to the current conditions in which the increase in domestic water demand is met by a similar level of growth in desalination capacity. On the supply side, this study proposed increasing the reuse of treated wastewater effluent in irrigation and looked into the possibility of recovering a liquid fraction by anaerobic digestion of municipal solid waste for use in irrigation. Results revealed that maintaining the current approach to water demand management could result in domestic water demand exceeding supply by 12-51% in 2100, with a need to expand the desalination and water supply infrastructure capacity starting 2030-2040. Increasing water tariffs could reduce national demand by 24%, which would keep domestic water demand below the current supply capacity up to the year 2100 or delay the need for further expansion of the desalination and water supply infrastructure by several decades in comparison to the current conditions, depending on the projected population. The reuse of treated greywater in future residential units, however, could only save up to 1.7-8.4% of the national demand, assuming a 100% response rate and a 20-50% reduction in domestic water use by recycling greywater. In terms of irrigation water supply, reusing 30-45% of the treated wastewater effluent can cover 32-56% of the agricultural sector water needs by 2100. Results also showed that the liquid fraction that can be potentially generated by anaerobic digestion of organic waste in Qatar covers merely 0.2% of the groundwater abstraction and therefore is not a promising source of water for use in irrigation.