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==Non-conventional water resources==
The s … ==Non-conventional water resources==
The second research question inquiries about the potential water increments/savings to be reached through the implementation of non-conventional water resources (NCWR). They can be used as a complement to conventional water resources to relieve water scarcity in regions where renewable water resources are insufficient. Qadir et al. (2007) present an interesting review on NCWR with focus on food-security in Middle East and North Africa. Desalination of seawater and highly brackish groundwater, rainwater harvesting and the use of marginal-quality water resources for irrigation are mentioned as alternatives for water augmentation at different scales.
ENB countries show little and scattered efforts on the road of NCWR. Desalination in Egypt has been given low priority because the cost of treatment is high compared with other sources (MWRI, 2014). Several desalination plants operate on the coasts of the Red Sea and the Mediterranean Sea to provide water for seaside resorts and hotels (FAO-AQUASTAT, 2015), where the value of water is high enough to cover the treatment costs (MWRI, 2014). Sudan started to walk the same road, provided seawater desalination has been recently introduced in Port Sudan town (FAO-AQUASTAT, 2015)
In terms of rainwater harvesting and the reuse of drainage and wastewater, the difference among the countries is notorious. In Egypt, rainfall occurs only in winter and it cannot be considered a reliable source provided its high spatial and temporal variability (MWRI, 2014). Despite of this, rainwater harvesting is practiced in the regions of Matruh and North Sinai (FAO-AQUASTAT, 2015). On the other hand, traditional water harvesting practices are found in all the states of Sudan, where small reservoirs catch rainfall and runoff for domestic use in villages and pastoralists in remote areas (FAO-AQUASTAT, 2015). Concerning water reuse, about 25 to 30% of agricultural drainage of irrigation water in areas on both sides of the Nile Valley returns to the River Nile or main irrigation canals in Upper Egypt and in the southern Delta. Also, Egypt takes the lead in the region by treating part of its municipal wastewater and reusing it for irrigation either directly or mixed with drainage water (FAO-AQUASTAT, 2015; MWRI, 2014).
The region shows potential for increasing, improving and introducing NCWR. As an instance on this regard, I look at good examples within and outside ENB. A small country, Singapore hosts 3.4 million people inside 720 square kilometers of territory (similar to New York City). Despite its lack of natural water resources and pollution in its rivers, this “big city” overcome water shortages by building a robust, diversified and sustainable water supply system out of four different sources known as the Four National Taps, referencing local rainwater harvesting, wastewater reuse, desalination technology and imported water (PUB, 2015)
Singapore had mostly water quality problems due to discharges of raw wastewater from households and formal and informal economic activities (pig farms, shipbuilding industry, etc.). This forced the country to ration the water supply and thereby depend deeply on water transfer from the neighbor country Malaysia. In the period 1977-1987, eleven government agencies worked together to reverse an unsustainable reality.
Today, the country collects water from 2/3 of its territory through an 8,000-Km drain network and storages it in 17 reservoirs. It also recycles wastewater using micro-filtration, reverse osmosis and ultraviolet disinfection, which is used to cover 30% of freshwater demand, mainly in the industry sector and for topping up reservoirs in dry seasons. In addition, Singapore uses reverse osmosis to turn seawater into freshwater, meeting 25% of the demand. Finally, the country’s fourth tap comes through an agreement with Malaysia, valid until 2061, which enables the island to withdraw up to 250 MGD from the Johor River (Tang, 2015)
I believe there might be something to learn from Singapore that could be applied in the densely populated cities of Cairo and Khartoum, which host more than 18 and 5 million people respectively?than 18 and 5 million people respectively? +
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