لخّصلي

St, Cairo, Egypt article info Article history: Received 16 December 2019 Revised 9 February 2020 Accepted 1 March 2020 Available online 13 March 2020 Keywords: River Nile High Dam Lake Toushka Climate change Grand Ethiopian Renaissance Dam Contents abstract Worldwide, water resources problems will be one of the most significant economic and social issues of the century. As there are limited water resources due to its fixed share of the Nile water, Egypt is one of the countries that will face great challenges, and limitation of groundwater, rainfall and desalination water. Climate change plays an important role in imposing an additional burden on water availability and accessibility in Egypt. The upper Nile basin countries’ increased competition on water (The Grand Ethiopian Renaissance Dam) may lead to water shortage. Although, Lake Nasser budget of water repre- sents the national freshwater bank of Egypt, depending on the water inflow through the Nile discharge and the water outflow through the High dam, there is still water loss by the evaporation and limited water seepage from Lake Nasser. The Toushka project is part of a national scheme to reform this pattern of skewed population potentials distribution. Ó 2020 National Institute of Oceanography and Fisheries. Hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Introduction............................................................................................................. 2 FreshwaterresourcesinEgypt.............................................................................................. 4 RiverNile........................................................................................................... 4 Groundwater........................................................................................................ 4 Rainwater .......................................................................................................... 4 Reuseofdrainagewastewater.......................................................................................... 5 Waterdesalination................................................................................................... 5 ThewaterresourcesfuturechallengesinEgypt................................................................................ 5 Climatechangeimpact................................................................................................ 5 GrandEthiopianRenaissanceDam....................................................................................... 5 Projectsofmanagementwaterresources..................................................................................... 5 HighDamprojectandLakeNasser...................................................................................... 5 HighDamLakemorphometry.................................................................................... 7 WaterinflowandoutflowoftheHighDamLake .................................................................... 7 WaterlossduetoevaporationfromHighDamLake .................................................................. 8 WaterseepagefromHighDamLake............................................................................... 9 RainfalloverHighDamLake ..................................................................................... 9 WaterbudgetoftheHighDamLake............................................................................... 9 BathymetricstudyofsomekhorsinLakeNasser..................................................................... 9 Toushkaproject(TheNewValley)...................................................................................... 10 Conclusion............................................................................................................. 10 References........................................................................................................... 11 Peer review under responsibility of National Institute of Oceanography and Fisheries. E-mail address: [email protected] https://doi.org/10.1016/j.ejar.2020.03.001 1687-4285/Ó 2020 National Institute of Oceanography and Fisheries. Hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

2 R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12 Introduction Earth is referred to as the water plant. Water represents almost three-quarters of its surface. Most of this water is saltwater (Shiklomanov, 1998). Less than 3 percent of this water is freshwa- ter (Fig. 1), and most of it exists in the form of ice and snow in polar glaciers (Gleick, 1993). Note that there are other opinions for Bengtsson (2010) and Koutsoyiannis (2011) about the distribution of global water. The quantity of earth’s freshwater that is available depends on the global water cycle. In the present time, available freshwater in most countries is one of the great challenges that will be increased in the future. The major global concerns like climate change, food security, human health, economic development, and regional conflicts are connected to freshwater availability (Schuol, Abbaspour, Srinivasan, & Yang, 2008). Sircoulon (1991) summarized this fact, stating that there is an increasing awareness of the significant relationship between climate, water (lakes and rivers), and environment. Climate, and consequently lakes level changes, cause an accumulation of additional problems to the sur- rounding environment. On the other hand, changes in climate and water circulation affect the water chemistry and biological ecosys- tem. The knowledge about lakes is based on the observation of the dimensions and characteristic of the lakes’ water. The majority of the world’s populations live near continental water bodies. The inland water bodies like rivers, lakes, wetlands and floodplains are sources of water, fish, navigation and produc- tion of hydroelectric power. As many catchment areas are often focal points in terms of environmental and conservation issues, they have been shown to be good proxy indicators of local, regional and global climatic change (Benveniste & Berry, 2004). The Intergovernmental Panel on Climate Change’s (IPCC, 2007) predictions indicated that over the next decades, the increased Fig. 1. Distribution of the Global water (Alberta Environment). Fig. 2. Availably of water supply in Egypt (billion m3) (Ministry of water resources and irrigation, MWRI).

R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12 3 Fig. 3. The countries of Nile River Basin (The World Bank). water stress will be affecting between 75 and 250 million people due to the climate change. The same report states that the develop- ing countries, including African countries, are the most at risk of being severely affected by climate change. Egypt is located at the most north-eastern corner of Africa, covering an area of nearly one million square kilometers. It is bounded on the north by the

4 R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12 coast of the Mediterranean Sea, and the coast of Red Sea on the east. Egypt reached the highest population in Africa of over 100 million in 2020. It has experienced rapid population growth, which leads to additional demand of water due to its limited water resources. It is predicted that Egypt’s total population will be about 110 million by the year 2025 (Ferrari, McDonald, & Osman, 2014). Due to the high population and geographic location of Egypt, there is an increasing demand for water and decreasing per capita water share. Since 1990s, Egypt already has one of the lowest per capita water shares in the world. This article highlights three main objec- tives: 1) Egypt’s water resources and their challenges. 2) The water resources’ future challenges in Egypt. 3) Water resources manage- ment projects (High Dam project and Toushka project). Freshwater resources in Egypt In the present time, freshwater resources occupy a top place among other natural resources on the planet. Freshwater is dis- tributed by different amounts everywhere. Egypt is characterized by a dry climate, scarce rainfall, the desert covers most of the land, and its water supplies are uncertain (Allam & Allam, 2007). As the Egyptian water resources system is complex and uncertain, thus the major challenge is to treat the problem of the rapidly increas- ing gap between the limited water resources and the rising demand for freshwater. Water resources in Egypt are limited (Fig. 2) either conventional or non-conventional water resources. The Nile River inflow, the groundwater, as well as the rainfall rep- resent the conventional water resources in Egypt. However, seawa- ter desalination and the use of wastewater represent the non- conventional water resources (Djuma, Bruggeman, Eliades, & Lange, 2016). River Nile The Nile river is the second longest river in the world, 6695 km long, and covers an area of about 2.9 million km2 (Moustafa, 1991). It has one of the largest catchment areas in the world. The River (Fig. 3) starts from the center of Africa passing through Tanzania, Burundi, Rwanda, Kenya, Congo, Uganda, Ethiopia, Eretria, South Sudan, Sudan and Egypt (Muala, Mohamed, Duan, & van der Zaag, 2014). The Ethiopian Plateau provides 86% of the Nile flow (Blue Nile (59%), Sobat (14%) and Atbara (13%)), while the contribu- tion from the Equatorial Lakes region is only 14% (the White Nile) (Swain, 2011). Because of rainfall in Egypt is very scarce, the Egyptian popula- tions rely on the Nile River for all water needs and the vast major- ity of them lives in close proximity to the Nile River (Ibrahim, Al- Zyoudand, & Elhaddad, 2018). As the River Nile’s sources are located outside the Egyptian border, the River’s land is highly vul- nerable to changing climate conditions and is affected both inside and outside its borders. The impact of climate change on the River Nile flow, may be the reason for both flood and drought incidences in Egypt. Groundwater The groundwater (Fig. 4) is the second source of freshwater in Egypt, and represents about 12% of water supply (Abo-El-Fadl, 2013). Groundwater in both the Nile and desert aquifers is not an easily renewable resource (Soliman & Soliman, 2017). Although groundwater is an important source of water, there areseveral challenges. The high consumption of groundwater in Egypt has led to exceeding the safe yield and overexploiting the aquifer sys- tems. The physical and chemical properties of the groundwater dif- fer from surface water related to the environment in which it occurs. Groundwater is affected by surface activities, rainwater seepage, irrigation water and drainage water and other effluents (Elnashar, 2014). The aquifers in northern Egypt are at risk due to saltwater seepage in many coastal aquifers. On the other hand, the effect on groundwater is directly related to the influence of cli- mate change on recharge rates, which can decrease in proportion to decrease in precipitation and vice versa. Rainwater Most of Egypt is considered to be a hyperarid country (Awadallah, Magdy, Helmy, & Rashed, 2017), receives very little rainfall (Abdel-Maksoud, 2018). Rainwater is concentrated on the narrow strip of land along the coast of Egypt, and decreases grad- ually to the south (Abou Rayan, Djebedijian, & Khaled, 2004). It is raining only in winter in the form of scattered showers. According Fig. 5. Average annual precipitation in Egypt (mm per year) (MWRI). Fig. 4. The major aquifers systems in Egypt (MWRI).

to Abdel-Shafy, El-Saharty, Regelsberger, and Platzer (2010), the mean annual rainfall is between 0 mm in the desert to 200 mm in the north coastal region (Fig. 5) with an annual average about 12 mm. The total amount of rainwater is about one billion m3 per year. It cannot be a reliable water resource as it differs from region to region and time to time. According to Christensen, Hewitson, Busuioc, and Chen (2007), it is predicted that the annual rainfall will decrease in most of Mediterranean African countries and northern Sahara including Egypt. Reuse of drainage wastewater Because of the fact that water demand is larger than the con- ventional supply in Egypt, the utilization of non-conventional water resources became essential. Egypt is one of the pioneer countries in the reuse of water. This process started by 1920 (Abu-Zeid & Elrawady, 2014). In Upper Egypt, drainage water is reused indirectly, as it returns to the Nile. Reused water in the Delta comes from agricultural land. The future plans of Egypt are to reuse additional three billion cubic meters per year for the Al Salam Canal Project and for the supply of the Nubaria Canal. Nowa- days, treated sewage and industrial effluent may provide approxi- mately three billion cubic meters per year (Abdin & Gaafar, 2009). With the importance of reusing drainage water, there are limited factors of agricultural drainage reuse. The excessive reuse causes the accumulation of salts in the agricultural land. The seepage of drainage water may include toxic pollution and chemical elements that cause harm to aquifers (Abu-Zeid & Elrawady, 2014). Water desalination Desalination operation involves three main branches seawater desalination, groundwater desalination and desalination of wastewater. As mentioned earlier, Egypt has long shorelines on both the Red Sea and the Mediterranean Sea. It is already one of the pioneer countries using seawater desalination as a mean of water supply (Fried & Serio, 2012). Concerning seawater desalina- tion, there is modern technological methods, which are suggested to be used in Egypt in this field, as many sectors like tourism, pet- roleum, urban coastal communities and industry are depending on this water resource. Egypt includes vast reserves of brackish groundwater, and great potential for the water desalination, which can be applied at much lower cost. Treatment of drainage water is one of the new fields of application for which large quantities of water are available in Egypt (Abdin & Gaafar, 2009). Desalination is considered one of the alternatives for producing freshwater in the presence of abundant energy availability. Desali- nation cost is highly variable and is affected significantly by many factors. These factors include water quality, technology, energy cost, plant capacity and plant availability (Batisha, 2007). The water resources future challenges in Egypt Today, the first concern in deciding the future directions is to look closely at water resources challenges. Although the main chal- lenges regarding freshwater in Egypt include increasing urban demand, land-use changes and environmental requirements (Sugita, Matsuno, El-Kilani, & Abdel-Fati, 2017), the climate change is happening with severe and diverse impacts, (Sutcliffe, Hurst, Awadallah, Brown, & Hamed, 2016) and the Ethiopian Renaissance Dam represents the most prominent challenge (Abdelhaleem & Helal, 2015). Climate change impact In the present time, the climate change is inevitable (Koutsoyiannis, 2013) where water sector is the most vulnerable to this change (Rosegran, Cai, & Cline, 2002; Elba, Urban, Ettmerand, & Farghaly, 2017). Egypt is one of the countries affected by climate change impacts, within its borders and outside its bor- ders, within the whole Nile Basin. It is strongly predicted that the River Nile levels will experience major decrease (Fig. 6). Conway (2005) and Hailea, Akawkab, Berhanua, and Rientjes (2017) found that there is no clear indication of how River Nile flow would be affected by climate change. However, Khordagui (2007) expected that the Nile water would be decreased by 20% over the next 50 years. Meanwhile, the rising temperatures will cause an increase in the evaporation process in natural ecosystems, which will lead to an increased water demand (IPCC, 2007). There- fore, a decrease in rainfall and an increase in evaporation lead to decreased groundwater recharge. It is expected that such dry con- ditions and rainfall decrease will put more pressure on available water resources. Moreover, increasing temperatures and conse- quently sea level rise will lead to seawater intrusion in the coastal groundwater aquifers (Iglesias, Garrote, Flores, & Moneo, 2007). Grand Ethiopian Renaissance Dam The Blue Nile is the largest tributary of the Nile River, providing a vital source of the freshwater to Sudan and Egypt (Conway, 1997). The Blue Nile contributes from 60% to 70% of the total annual River Nile discharge (Di Baldassarre et al., 2011). Recently the Ethiopian Renaissance Dam (Fig. 3) represents the most promi- nent challenge that poses the greatest threat to Egypt’s water secu- rity (Mulat & Moges, 2014). In light of the available information on the Renaissance Dam, it will be 170 m high with a 74 billion m3- storage capacity (Tawfik, 2015). The Grand Ethiopian Renaissance Dam will become the largest dam for hydroelectric power in Africa (Ferrari, McDonald, & Osman, 2013; Tesfa, 2013). Since the fifties, Egypt’s share of water has not changed despite the high population and high rates of development; accordingly the Renaissance Dam directly affects that share of the Nile water (El Bedawy, 2014). There are two direct effects on the Nile dis- charge; the reservoir capacity of the Dam is roughly equivalent to the annual flow of the Nile water to Egypt and the evaporative losses from the dam’s reservoir would permanently reduce the flow of the Blue Nile (Ferrari et al., 2013). It is certain that the con- struction of the Grand Ethiopian Renaissance Dam will affect the quota of Egypt and result in a fall in the water levels of Lake Nasser (Mostafa & Peters, 2015). The low discharge through the Aswan High Dam will lead to the reduction of its power generation (Abdelhaleem & Helal, 2015). The lowering of the lake’s level will lead to a decline in fisheries and thus the socio-economic status of the fishing community. Projects of management water resources To improve management of the main water resource in Egypt, the Aswan High Dam was constructed in southern Egypt and the Toushka project in the western desert of Egypt. High Dam project and Lake Nasser The River Nile has sustained the existence of the fertile land and supported man’s early civilization. The availability of Nile water has been a determining factor for Egyptian society. Many dams exist along the river Nile for various purposes; storage, irrigation and hydro-electrical power (Moussa, 2013). R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12 5

6 R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12 Fig. 6. Runoff change over the Nile Basin (Hassan et al, 2018). The High Dam a of the khors is about 4,900 million m2, which represents 79% of the lake’s area, but in volume they contain only 86.4 billion m3, which represents 55% of the total lake volume. Water inflow and out flow of the High Dam Lake According to the 1959 treaty (Swain, 2011), the average Aswan natural flow of the River Nile is 84 billion m3 per year, of which

8 R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12 Fig. 8. The monthly inflow and outflow of the High Dam Lake (WWRI). Fig. 9. The Daily evaporation rate of Lake Nasser (Hassan et al, 2013). 18.5 billion m3is ascribed to Sudan and 55.5 billion m3is ascribed to Egypt. The rest is assumed to be lost to evaporation and seepage. In general, the water inflow upstream and outflow that is released from the Lake through High Dam gates changes on monthly basis (Fig. 8). The released water outflow through the High Dam is annu- ally fixed to meet the downstream water requirements (irrigation and navigation) of Egypt. The low water outflow is released during December and January. The high water outflow, requirements for Egypt through the whole year, is during June and July (Abd Ellah, 2009). Water loss due to evaporation from High Dam Lake The High Dam Lake has an enormous storage capacity of more than 168 billion m3. As it is situated in a very hot and dry region,

R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12 9 Fig. 10. Relation between Lake’s level and seepage (Hamdan et al., 2013). the High Dam Lake can lose up to 10% of its volume to evaporation annually (Mutua & Mtalo, 1, Bauwens, W., 2005). According to Hassan (2013), the rate of evaporation over the northern region of Lake Nasser is higher than the rate of evaporation in the south- ern part of Lake Nasser (Fig. 9). The calculations revealed a rate of 7.64 mm per day as the annual mean evaporation rate with a max- imum value in June of 10.63 mm per day and a minimum in December of 4.25 mm per day. The mean evaporation losses are estimated to be 7.4 mm per day, equal to 2.7 m per year. The annual water loss by evaporation was in order of 10.6 billion m3 (Elsawwaf & Willems, 2012). Water seepage from High Dam Lake For the High Dam Lake, there are three main geological regions. The basement complex is in the first 50 km south of the High Dam. The Nubian sandstone occupies 300 km at the middle of the Lake. The extreme southern 150 km is a granite basement (Zaghloul et al., 2012). Hamdan, Selim, and Zaki (2013) referred that the water seepage changes from year to another, depending on the Lake’s level (Fig. 10) and the groundwater in the area (Abdel Moneim, Zaki, & Diab, 2014). They calculated the mean water seep- age from Lake Nasser of about 47.5 million m3 per year. Rainfall over High Dam Lake Lake Nasser is located on the eastern side of the great Saharan belt. It receives rare rainfall through occasional thunderstorms, which sporadically penetrate the area (Elshemy & Meon, 2011). El-Bakry (1993) reported that the rainfall during 30 year is grouped in 6 categories as shown in table 2.The climate of the Lake area is extremely arid with negligible rainfall of less than 5 mm annually. Water budget of the High Dam Lake Determining the water budget could help in understanding the impacts of several variabilities and obtaining better management scenarios for the Lake (Abdel-Latif & Yacoub, 2011). The water Table 2 The rainfall categories for a period of 30 years over Lake Nasser (Egyptian Metrological Authority, EMA). Number of Year Rain in mm 80 11 Trace 5 11 3 1to1.6 2 7.2 1 27.3 balance of a lake as generally applied to the hydrologic cycle is actually a statement of the law of conservation of mass. It is based upon the hydrologic equation as follows: Inflow 1⁄4 Outflow þ DStorage ð1Þ The High Dam Lake is located in a subtropical and arid zone, the rainfall is nearly rare, and therefore the water budget of the High Dam Lake can be summarized as follows (Hamdan & Zaki, 2016): I1⁄4OþE þ SDV ð2Þ where, I is the water inflow, O is the water outflow, E is the water loss due to the evaporation, E is the water loss due to the seepage and DV is the changes in water storage of the Lake. The DV is pos- itive value when water gained by the inflow is higher than water lost by the outflow, the evaporation and the seepage and vice versa. Bathymetric study of some khors in Lake Nasser The bathymetric information on Lake Nasser is an important issue. One of the most concerning features of the Lake is the com- plex nature of its shoreline, which depends on the change in its water level (Mostafa and Soussa, 2006; Elba, Farghaly, & Urban, 2014). Lake Nasser is a basic need in environmental planning, restoration and management. Knowledge of Lake Nasser is based

10 R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12 Fig. 11. Bathymetric charts of some khors in Lake Nasser (Abd Ellah and El-Geziry, 2016). on observation of the dimensions of its water basins. Concerning the bathymetry of the lake, the changing conditions in the water body; such as the water level, are the results of the rapidly change of bathymetric conditions. Abd Ellah and El-Geziry (2016) reported that, the Lake’s Khors may have fluctuated in its area and morpho- metrical features, with water level (Fig. 11). Toushka project (The New Valley) The New Valley is located in the northwest of Lake Nasser. It constitutes a major Egyptian project to claim a huge area of the Egyptian Western Desert for agriculture and industry by diverting freshwater from Lake Nasser (Elsawwaf, Feyen, Batelaan, & Bakr, 2014). In 2000, a pumping station and canal were constructed to convey water into the region. Fig. 7 shows the location of the Pumping Station on Lake Nasser and the spillway to the New Val- ley. A part of the 50-kilometerlong main canal is called the Sheikh Zayed Canal. Networks of canals were made to continue carrying Lake Nasser water to the new reclamation lands in the Western Desert (UNEP, 2010; Sparavigna, 2011). Toushka Project takes about 5 billion m3 of water from Lake Nasser each year. Toushka Project was planned to reclaim more than 3360 million m2 of empty desert and create a series of settlements for about 6 million Egyptians (Smakhtin, Molden, & Cascao, 2012). Conclusion In the present time, available freshwater all over the world is an essential issue and one of the most important challenges facing humanity, and increasingly in to the future. The Egyptian water Fig. 12. Global freshwater availability (World Resources Simulation Center, WRSC).

resources system is complex and uncertain. Availability of water in Egypt is highly variable and is considered as one of the biggest obstacles to socio-economic development. According to UNEP (2010), by 1990s, Egypt became under danger of water scarcity (Fig. 12). Egypt as a barren country depending on the Nile River as its main water resource is suffering water stress due to the lim- ited supplies and growing population, as well as increased compe- tition for water from the upper Nile Basin’s countries. The climate change influences on the Nile discharge and can be considered as another challenge for water resources in Egypt. Since 1990s, the rapidly increasing gap between the limited water resources and the escalating demand for that water became the major challenge that faces Egypt. Water resources in Egypt are limited, either conventional water resources or non-conventional water resources. In general, the main challenges regarding freshwater in Egypt are as following: & The rapidly growing population and increased water demand for public water supplies that are related to this increase. (Pop- ulation of 100 million in 2020). & TheincreasedcompetitiononwaterfromtheNileBasin’scoun- tries and the expected Nile flow reduction because of the rapid implementation plans of the Grand Ethiopian Renaissance Dam. & The expected impacts of climate change on the River Nile Basin and its flows, which are considered as the main freshwater source. & The low rate of renewable water resources, high rate of con- sumption, and the seepage of drainage water in to aquifers. & Egypt is an arid country and the rainfall is very low, except in narrow bands along the northern coastal areas. & There are environmental problems with drainage water reuse. & The high cost of the seawater desalination wastewater treat- ments processes. To improve the management of the main water resource in Egypt, the Aswan High Dam was constructed at southern Egypt. The Dam aims to control the discharges and fluctuations in the Nile River water, create water storage up stream as a reservoir of fresh- water, and produce hydroelectric power. Lake Nasser represents the national freshwater bank of Egypt. Finally, the major part of Egypt is desert (more than 95% of total area). Most of the develop- ment concentrates in the Nile valley and Delta. Toushka is consid- ered one of the Projects to improve management of the main water resource in Egypt. The Toushka project is part of a national scheme to reform this pattern of skewed population and distribution potential. The Project (New Valley) depends on conveying Nile River water from Lake Nasser to the newly reclaimed lands in the Western Desert. References Abd Ellah, R.G., 2009. Thermal stratification in Lake Nasser (Egypt) using field measurements. 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St, Cairo, Egypt
article info
Article history:
Received 16 December 2019 Revised 9 February 2020 Accepted 1 March 2020 Available online 13 March 2020
Keywords:
River Nile
High Dam Lake
Toushka
Climate change
Grand Ethiopian Renaissance Dam
Contents
abstract
Worldwide, water resources problems will be one of the most significant economic and social issues of the century. As there are limited water resources due to its fixed share of the Nile water, Egypt is one of the countries that will face great challenges, and limitation of groundwater, rainfall and desalination water. Climate change plays an important role in imposing an additional burden on water availability and accessibility in Egypt. The upper Nile basin countries’ increased competition on water (The Grand Ethiopian Renaissance Dam) may lead to water shortage. Although, Lake Nasser budget of water repre- sents the national freshwater bank of Egypt, depending on the water inflow through the Nile discharge and the water outflow through the High dam, there is still water loss by the evaporation and limited water seepage from Lake Nasser. The Toushka project is part of a national scheme to reform this pattern of skewed population potentials distribution.
Ó 2020 National Institute of Oceanography and Fisheries. Hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Introduction............................................................................................................. 2 FreshwaterresourcesinEgypt.............................................................................................. 4 RiverNile........................................................................................................... 4 Groundwater........................................................................................................ 4 Rainwater .......................................................................................................... 4 Reuseofdrainagewastewater.......................................................................................... 5 Waterdesalination................................................................................................... 5 ThewaterresourcesfuturechallengesinEgypt................................................................................ 5 Climatechangeimpact................................................................................................ 5 GrandEthiopianRenaissanceDam....................................................................................... 5 Projectsofmanagementwaterresources..................................................................................... 5 HighDamprojectandLakeNasser...................................................................................... 5 HighDamLakemorphometry.................................................................................... 7 WaterinflowandoutflowoftheHighDamLake .................................................................... 7 WaterlossduetoevaporationfromHighDamLake .................................................................. 8 WaterseepagefromHighDamLake............................................................................... 9 RainfalloverHighDamLake ..................................................................................... 9 WaterbudgetoftheHighDamLake............................................................................... 9 BathymetricstudyofsomekhorsinLakeNasser..................................................................... 9 Toushkaproject(TheNewValley)...................................................................................... 10 Conclusion............................................................................................................. 10 References........................................................................................................... 11
Peer review under responsibility of National Institute of Oceanography and Fisheries.
E-mail address: [email protected]
https://doi.org/10.1016/j.ejar.2020.03.001
1687-4285/Ó 2020 National Institute of Oceanography and Fisheries. Hosting by Elsevier B.V.
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

2 R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12
Introduction
Earth is referred to as the water plant. Water represents almost three-quarters of its surface. Most of this water is saltwater (Shiklomanov, 1998). Less than 3 percent of this water is freshwa- ter (Fig. 1), and most of it exists in the form of ice and snow in polar glaciers (Gleick, 1993). Note that there are other opinions for Bengtsson (2010) and Koutsoyiannis (2011) about the distribution of global water. The quantity of earth’s freshwater that is available depends on the global water cycle. In the present time, available freshwater in most countries is one of the great challenges that will be increased in the future. The major global concerns like climate change, food security, human health, economic development, and regional conflicts are connected to freshwater availability (Schuol, Abbaspour, Srinivasan, & Yang, 2008). Sircoulon (1991) summarized this fact, stating that there is an increasing awareness
of the significant relationship between climate, water (lakes and rivers), and environment. Climate, and consequently lakes level changes, cause an accumulation of additional problems to the sur- rounding environment. On the other hand, changes in climate and water circulation affect the water chemistry and biological ecosys- tem. The knowledge about lakes is based on the observation of the dimensions and characteristic of the lakes’ water.
The majority of the world’s populations live near continental water bodies. The inland water bodies like rivers, lakes, wetlands and floodplains are sources of water, fish, navigation and produc- tion of hydroelectric power. As many catchment areas are often focal points in terms of environmental and conservation issues, they have been shown to be good proxy indicators of local, regional and global climatic change (Benveniste & Berry, 2004).
The Intergovernmental Panel on Climate Change’s (IPCC, 2007) predictions indicated that over the next decades, the increased
Fig. 1. Distribution of the Global water (Alberta Environment).
Fig. 2. Availably of water supply in Egypt (billion m3) (Ministry of water resources and irrigation, MWRI).

R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12 3
Fig. 3. The countries of Nile River Basin (The World Bank).
water stress will be affecting between 75 and 250 million people due to the climate change. The same report states that the develop- ing countries, including African countries, are the most at risk of
being severely affected by climate change. Egypt is located at the most north-eastern corner of Africa, covering an area of nearly one million square kilometers. It is bounded on the north by the

4 R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12
coast of the Mediterranean Sea, and the coast of Red Sea on the east. Egypt reached the highest population in Africa of over 100 million in 2020. It has experienced rapid population growth, which leads to additional demand of water due to its limited water resources. It is predicted that Egypt’s total population will be about 110 million by the year 2025 (Ferrari, McDonald, & Osman, 2014). Due to the high population and geographic location of Egypt, there is an increasing demand for water and decreasing per capita water share. Since 1990s, Egypt already has one of the lowest per capita water shares in the world. This article highlights three main objec- tives: 1) Egypt’s water resources and their challenges. 2) The water resources’ future challenges in Egypt. 3) Water resources manage- ment projects (High Dam project and Toushka project).
Freshwater resources in Egypt
In the present time, freshwater resources occupy a top place among other natural resources on the planet. Freshwater is dis- tributed by different amounts everywhere. Egypt is characterized by a dry climate, scarce rainfall, the desert covers most of the land, and its water supplies are uncertain (Allam & Allam, 2007). As the Egyptian water resources system is complex and uncertain, thus the major challenge is to treat the problem of the rapidly increas- ing gap between the limited water resources and the rising demand for freshwater. Water resources in Egypt are limited (Fig. 2) either conventional or non-conventional water resources. The Nile River inflow, the groundwater, as well as the rainfall rep- resent the conventional water resources in Egypt. However, seawa- ter desalination and the use of wastewater represent the non- conventional water resources (Djuma, Bruggeman, Eliades, & Lange, 2016).
River Nile
The Nile river is the second longest river in the world, 6695 km long, and covers an area of about 2.9 million km2 (Moustafa, 1991). It has one of the largest catchment areas in the world. The River (Fig. 3) starts from the center of Africa passing through Tanzania, Burundi, Rwanda, Kenya, Congo, Uganda, Ethiopia, Eretria, South Sudan, Sudan and Egypt (Muala, Mohamed, Duan, & van der Zaag, 2014). The Ethiopian Plateau provides 86% of the Nile flow
(Blue Nile (59%), Sobat (14%) and Atbara (13%)), while the contribu- tion from the Equatorial Lakes region is only 14% (the White Nile) (Swain, 2011).
Because of rainfall in Egypt is very scarce, the Egyptian popula- tions rely on the Nile River for all water needs and the vast major- ity of them lives in close proximity to the Nile River (Ibrahim, Al- Zyoudand, & Elhaddad, 2018). As the River Nile’s sources are located outside the Egyptian border, the River’s land is highly vul- nerable to changing climate conditions and is affected both inside and outside its borders. The impact of climate change on the River Nile flow, may be the reason for both flood and drought incidences in Egypt.
Groundwater
The groundwater (Fig. 4) is the second source of freshwater in Egypt, and represents about 12% of water supply (Abo-El-Fadl, 2013). Groundwater in both the Nile and desert aquifers is not an easily renewable resource (Soliman & Soliman, 2017). Although groundwater is an important source of water, there areseveral challenges. The high consumption of groundwater in Egypt has led to exceeding the safe yield and overexploiting the aquifer sys- tems. The physical and chemical properties of the groundwater dif- fer from surface water related to the environment in which it occurs. Groundwater is affected by surface activities, rainwater seepage, irrigation water and drainage water and other effluents (Elnashar, 2014). The aquifers in northern Egypt are at risk due to saltwater seepage in many coastal aquifers. On the other hand, the effect on groundwater is directly related to the influence of cli- mate change on recharge rates, which can decrease in proportion to decrease in precipitation and vice versa.
Rainwater
Most of Egypt is considered to be a hyperarid country (Awadallah, Magdy, Helmy, & Rashed, 2017), receives very little rainfall (Abdel-Maksoud, 2018). Rainwater is concentrated on the narrow strip of land along the coast of Egypt, and decreases grad- ually to the south (Abou Rayan, Djebedijian, & Khaled, 2004). It is raining only in winter in the form of scattered showers. According
Fig. 5. Average annual precipitation in Egypt (mm per year) (MWRI).
Fig. 4. The major aquifers systems in Egypt (MWRI).

to Abdel-Shafy, El-Saharty, Regelsberger, and Platzer (2010), the mean annual rainfall is between 0 mm in the desert to 200 mm in the north coastal region (Fig. 5) with an annual average about 12 mm. The total amount of rainwater is about one billion m3 per year. It cannot be a reliable water resource as it differs from region to region and time to time. According to Christensen, Hewitson, Busuioc, and Chen (2007), it is predicted that the annual rainfall will decrease in most of Mediterranean African countries and northern Sahara including Egypt.
Reuse of drainage wastewater
Because of the fact that water demand is larger than the con- ventional supply in Egypt, the utilization of non-conventional water resources became essential. Egypt is one of the pioneer countries in the reuse of water. This process started by 1920 (Abu-Zeid & Elrawady, 2014). In Upper Egypt, drainage water is reused indirectly, as it returns to the Nile. Reused water in the Delta comes from agricultural land. The future plans of Egypt are to reuse additional three billion cubic meters per year for the Al Salam Canal Project and for the supply of the Nubaria Canal. Nowa- days, treated sewage and industrial effluent may provide approxi- mately three billion cubic meters per year (Abdin & Gaafar, 2009). With the importance of reusing drainage water, there are limited factors of agricultural drainage reuse. The excessive reuse causes the accumulation of salts in the agricultural land. The seepage of drainage water may include toxic pollution and chemical elements that cause harm to aquifers (Abu-Zeid & Elrawady, 2014).
Water desalination
Desalination operation involves three main branches seawater desalination, groundwater desalination and desalination of wastewater. As mentioned earlier, Egypt has long shorelines on both the Red Sea and the Mediterranean Sea. It is already one of the pioneer countries using seawater desalination as a mean of water supply (Fried & Serio, 2012). Concerning seawater desalina- tion, there is modern technological methods, which are suggested to be used in Egypt in this field, as many sectors like tourism, pet- roleum, urban coastal communities and industry are depending on this water resource. Egypt includes vast reserves of brackish groundwater, and great potential for the water desalination, which can be applied at much lower cost. Treatment of drainage water is one of the new fields of application for which large quantities of water are available in Egypt (Abdin & Gaafar, 2009).
Desalination is considered one of the alternatives for producing freshwater in the presence of abundant energy availability. Desali- nation cost is highly variable and is affected significantly by many factors. These factors include water quality, technology, energy cost, plant capacity and plant availability (Batisha, 2007).
The water resources future challenges in Egypt
Today, the first concern in deciding the future directions is to look closely at water resources challenges. Although the main chal- lenges regarding freshwater in Egypt include increasing urban demand, land-use changes and environmental requirements (Sugita, Matsuno, El-Kilani, & Abdel-Fati, 2017), the climate change is happening with severe and diverse impacts, (Sutcliffe, Hurst, Awadallah, Brown, & Hamed, 2016) and the Ethiopian Renaissance Dam represents the most prominent challenge (Abdelhaleem & Helal, 2015).
Climate change impact
In the present time, the climate change is inevitable (Koutsoyiannis, 2013) where water sector is the most vulnerable to this change (Rosegran, Cai, & Cline, 2002; Elba, Urban, Ettmerand, & Farghaly, 2017). Egypt is one of the countries affected by climate change impacts, within its borders and outside its bor- ders, within the whole Nile Basin. It is strongly predicted that the River Nile levels will experience major decrease (Fig. 6).
Conway (2005) and Hailea, Akawkab, Berhanua, and Rientjes (2017) found that there is no clear indication of how River Nile flow would be affected by climate change. However, Khordagui (2007) expected that the Nile water would be decreased by 20% over the next 50 years. Meanwhile, the rising temperatures will cause an increase in the evaporation process in natural ecosystems, which will lead to an increased water demand (IPCC, 2007). There- fore, a decrease in rainfall and an increase in evaporation lead to decreased groundwater recharge. It is expected that such dry con- ditions and rainfall decrease will put more pressure on available water resources. Moreover, increasing temperatures and conse- quently sea level rise will lead to seawater intrusion in the coastal groundwater aquifers (Iglesias, Garrote, Flores, & Moneo, 2007).
Grand Ethiopian Renaissance Dam
The Blue Nile is the largest tributary of the Nile River, providing a vital source of the freshwater to Sudan and Egypt (Conway, 1997). The Blue Nile contributes from 60% to 70% of the total annual River Nile discharge (Di Baldassarre et al., 2011). Recently the Ethiopian Renaissance Dam (Fig. 3) represents the most promi- nent challenge that poses the greatest threat to Egypt’s water secu- rity (Mulat & Moges, 2014). In light of the available information on the Renaissance Dam, it will be 170 m high with a 74 billion m3- storage capacity (Tawfik, 2015). The Grand Ethiopian Renaissance Dam will become the largest dam for hydroelectric power in Africa (Ferrari, McDonald, & Osman, 2013; Tesfa, 2013).
Since the fifties, Egypt’s share of water has not changed despite the high population and high rates of development; accordingly the Renaissance Dam directly affects that share of the Nile water (El Bedawy, 2014). There are two direct effects on the Nile dis- charge; the reservoir capacity of the Dam is roughly equivalent to the annual flow of the Nile water to Egypt and the evaporative losses from the dam’s reservoir would permanently reduce the flow of the Blue Nile (Ferrari et al., 2013). It is certain that the con- struction of the Grand Ethiopian Renaissance Dam will affect the quota of Egypt and result in a fall in the water levels of Lake Nasser (Mostafa & Peters, 2015). The low discharge through the Aswan High Dam will lead to the reduction of its power generation (Abdelhaleem & Helal, 2015). The lowering of the lake’s level will lead to a decline in fisheries and thus the socio-economic status of the fishing community.
Projects of management water resources
To improve management of the main water resource in Egypt, the Aswan High Dam was constructed in southern Egypt and the Toushka project in the western desert of Egypt.
High Dam project and Lake Nasser
The River Nile has sustained the existence of the fertile land and supported man’s early civilization. The availability of Nile water has been a determining factor for Egyptian society. Many dams exist along the river Nile for various purposes; storage, irrigation and hydro-electrical power (Moussa, 2013).
R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12 5

6 R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12
Fig. 6. Runoff change over the Nile Basin (Hassan et al, 2018).
The High Dam a of the khors is about 4,900 million m2, which represents 79% of the lake’s area, but in volume they contain only 86.4 billion m3, which represents 55% of the total lake volume.
Water inflow and out flow of the High Dam Lake
According to the 1959 treaty (Swain, 2011), the average Aswan natural flow of the River Nile is 84 billion m3 per year, of which

8 R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12
Fig. 8. The monthly inflow and outflow of the High Dam Lake (WWRI).
Fig. 9. The Daily evaporation rate of Lake Nasser (Hassan et al, 2013).
18.5 billion m3is ascribed to Sudan and 55.5 billion m3is ascribed to Egypt. The rest is assumed to be lost to evaporation and seepage. In general, the water inflow upstream and outflow that is released from the Lake through High Dam gates changes on monthly basis (Fig. 8). The released water outflow through the High Dam is annu- ally fixed to meet the downstream water requirements (irrigation and navigation) of Egypt. The low water outflow is released during
December and January. The high water outflow, requirements for Egypt through the whole year, is during June and July (Abd Ellah, 2009).
Water loss due to evaporation from High Dam Lake
The High Dam Lake has an enormous storage capacity of more than 168 billion m3. As it is situated in a very hot and dry region,

R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12 9
Fig. 10. Relation between Lake’s level and seepage (Hamdan et al., 2013).
the High Dam Lake can lose up to 10% of its volume to evaporation annually (Mutua & Mtalo, 1, Bauwens, W., 2005). According to Hassan (2013), the rate of evaporation over the northern region of Lake Nasser is higher than the rate of evaporation in the south- ern part of Lake Nasser (Fig. 9). The calculations revealed a rate of 7.64 mm per day as the annual mean evaporation rate with a max- imum value in June of 10.63 mm per day and a minimum in December of 4.25 mm per day. The mean evaporation losses are estimated to be 7.4 mm per day, equal to 2.7 m per year. The annual water loss by evaporation was in order of 10.6 billion m3 (Elsawwaf & Willems, 2012).
Water seepage from High Dam Lake
For the High Dam Lake, there are three main geological regions. The basement complex is in the first 50 km south of the High Dam. The Nubian sandstone occupies 300 km at the middle of the Lake. The extreme southern 150 km is a granite basement (Zaghloul et al., 2012). Hamdan, Selim, and Zaki (2013) referred that the water seepage changes from year to another, depending on the Lake’s level (Fig. 10) and the groundwater in the area (Abdel Moneim, Zaki, & Diab, 2014). They calculated the mean water seep- age from Lake Nasser of about 47.5 million m3 per year.
Rainfall over High Dam Lake
Lake Nasser is located on the eastern side of the great Saharan belt. It receives rare rainfall through occasional thunderstorms, which sporadically penetrate the area (Elshemy & Meon, 2011). El-Bakry (1993) reported that the rainfall during 30 year is grouped in 6 categories as shown in table 2.The climate of the Lake area is extremely arid with negligible rainfall of less than 5 mm annually.
Water budget of the High Dam Lake
Determining the water budget could help in understanding the impacts of several variabilities and obtaining better management scenarios for the Lake (Abdel-Latif & Yacoub, 2011). The water
Table 2
The rainfall categories for a period of 30 years over Lake Nasser (Egyptian Metrological Authority, EMA).
Number of Year Rain in mm
80
11 Trace
5 11
3 1to1.6 2 7.2
1 27.3
balance of a lake as generally applied to the hydrologic cycle is actually a statement of the law of conservation of mass. It is based upon the hydrologic equation as follows:
Inflow 1⁄4 Outflow þ DStorage ð1Þ
The High Dam Lake is located in a subtropical and arid zone, the rainfall is nearly rare, and therefore the water budget of the High Dam Lake can be summarized as follows (Hamdan & Zaki, 2016):
I1⁄4OþE þ SDV ð2Þ
where, I is the water inflow, O is the water outflow, E is the water loss due to the evaporation, E is the water loss due to the seepage and DV is the changes in water storage of the Lake. The DV is pos- itive value when water gained by the inflow is higher than water lost by the outflow, the evaporation and the seepage and vice versa.
Bathymetric study of some khors in Lake Nasser
The bathymetric information on Lake Nasser is an important issue. One of the most concerning features of the Lake is the com- plex nature of its shoreline, which depends on the change in its water level (Mostafa and Soussa, 2006; Elba, Farghaly, & Urban, 2014). Lake Nasser is a basic need in environmental planning, restoration and management. Knowledge of Lake Nasser is based

10 R.G. Abd Ellah / Egyptian Journal of Aquatic Research 46 (2020) 1–12
Fig. 11. Bathymetric charts of some khors in Lake Nasser (Abd Ellah and El-Geziry, 2016).
on observation of the dimensions of its water basins. Concerning the bathymetry of the lake, the changing conditions in the water body; such as the water level, are the results of the rapidly change
of bathymetric conditions. Abd Ellah and El-Geziry (2016) reported that, the Lake’s Khors may have fluctuated in its area and morpho- metrical features, with water level (Fig. 11).
Toushka project (The New Valley)
The New Valley is located in the northwest of Lake Nasser. It constitutes a major Egyptian project to claim a huge area of the Egyptian Western Desert for agriculture and industry by diverting freshwater from Lake Nasser (Elsawwaf, Feyen, Batelaan, & Bakr, 2014). In 2000, a pumping station and canal were constructed to convey water into the region. Fig. 7 shows the location of the Pumping Station on Lake Nasser and the spillway to the New Val- ley. A part of the 50-kilometerlong main canal is called the Sheikh Zayed Canal. Networks of canals were made to continue carrying Lake Nasser water to the new reclamation lands in the Western Desert (UNEP, 2010; Sparavigna, 2011). Toushka Project takes about 5 billion m3 of water from Lake Nasser each year. Toushka Project was planned to reclaim more than 3360 million m2 of empty desert and create a series of settlements for about 6 million Egyptians (Smakhtin, Molden, & Cascao, 2012).
Conclusion
In the present time, available freshwater all over the world is an essential issue and one of the most important challenges facing humanity, and increasingly in to the future. The Egyptian water
Fig. 12. Global freshwater availability (World Resources Simulation Center, WRSC).

resources system is complex and uncertain. Availability of water in Egypt is highly variable and is considered as one of the biggest obstacles to socio-economic development. According to UNEP (2010), by 1990s, Egypt became under danger of water scarcity (Fig. 12). Egypt as a barren country depending on the Nile River as its main water resource is suffering water stress due to the lim- ited supplies and growing population, as well as increased compe- tition for water from the upper Nile Basin’s countries. The climate change influences on the Nile discharge and can be considered as another challenge for water resources in Egypt. Since 1990s, the rapidly increasing gap between the limited water resources and the escalating demand for that water became the major challenge that faces Egypt.
Water resources in Egypt are limited, either conventional water resources or non-conventional water resources. In general, the main challenges regarding freshwater in Egypt are as following:
& The rapidly growing population and increased water demand for public water supplies that are related to this increase. (Pop- ulation of 100 million in 2020).
& TheincreasedcompetitiononwaterfromtheNileBasin’scoun- tries and the expected Nile flow reduction because of the rapid implementation plans of the Grand Ethiopian Renaissance Dam.
& The expected impacts of climate change on the River Nile Basin and its flows, which are considered as the main freshwater source.
& The low rate of renewable water resources, high rate of con- sumption, and the seepage of drainage water in to aquifers.
& Egypt is an arid country and the rainfall is very low, except in
narrow bands along the northern coastal areas.
& There are environmental problems with drainage water reuse.
& The high cost of the seawater desalination wastewater treat-
ments processes.
To improve the management of the main water resource in Egypt, the Aswan High Dam was constructed at southern Egypt. The Dam aims to control the discharges and fluctuations in the Nile River water, create water storage up stream as a reservoir of fresh- water, and produce hydroelectric power. Lake Nasser represents the national freshwater bank of Egypt. Finally, the major part of Egypt is desert (more than 95% of total area). Most of the develop- ment concentrates in the Nile valley and Delta. Toushka is consid- ered one of the Projects to improve management of the main water resource in Egypt. The Toushka project is part of a national scheme to reform this pattern of skewed population and distribution potential. The Project (New Valley) depends on conveying Nile River water from Lake Nasser to the newly reclaimed lands in the Western Desert.
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