Managing Drought and Water Stress in Northern Africa

Abstract

Northern Africa is a region surrounding the northern portion of the African continent. Northern Africa consists of five countries Egypt, Algeria, Morocco, Tunisia, and Libya. Northern Africa has semi-arid and arid desert climates and low rainfall. Over the past four decades, many areas in Northern Africa have faced drought which has become more widespread, prolonged and frequent due to climate variability and which may expedite a shortage of water and to a decrease in the land areas suitable for agriculture. In fact, limited water reserves, growing population and droughts are the main factors reflected in the increased consumption of freshwater. It is critical to understand a balance between water demand and supply by managing drought and water stress in the region.

1. Introduction

Earth is referred to as the water planet because 75% of Earth’s surface is covered by water. More than 97 per cent of the Earth’s water is contained within the oceans as saltwater. Less than 3 per cent of this water is freshwater, and most of it exists in glaciers, underground, lakes, rivers, and swamps. Water means life. Water is the key to sustainable development and is crucial for socio-economic and for human survival itself. The rise in population will increase water consumption which will intensify water demand, and this will limit the amount of water available per person (drinking, irrigation, industries and municipal needs). The most water-scarce areas are those with lack of freshwater resources and higher population growth rates. Water is also the core of climate change adaptation, serving as the major link between society and the environment. Climate change is already having many effects on the Earth and particularly on the water’s Earth. In future decades, climate change is predicted to affect availability and distribution of water (precipitation, river, groundwater…). Thus, the handling of water will become ever more critical. It is further estimated that by 2025, more than half of the world’s population will be living in water-stressed areas due to the world population growth, which is predicted to reach ~9.7B by 2050, causing further stress on water globally. Although water stress is a universal phenomenon, this chapter focuses on the continent of Africa with approximately 1.37B inhabitants [1] and more specifically the region of Northern Africa which includes a total of five countries, viz. Egypt, Algeria, Morocco, Tunisia and Libya (Figures 1 and 2). Despite, each country in Northern Africa with its geological characteristics (geographic and climatology) and water management history, Algeria, Morocco and Tunisia have many common characteristics [4]. A map of Northern Africa with water stress is shown in Figures 1 and 2.

Figure 1.

Map of Northern Africa [2].

Figure 2.

As comparison projected water stress in Africa in 2040, as per Water Resource Institute [3].

In Northern Africa, humans’ activities depend essentially on water availability. Climate change impacts Northern Africa’s water in different ways. It is a principal contributor to droughts (low precipitation and rising in temperature). Droughts are complicated phenomena generally associated with greatly reduced precipitation. Droughts are recurrent and often devastating threatening people’s livelihoods in Northern African countries. Droughts will likely continue to decrease the average water availability in an already water-scarce region. These poor water management threats have led North African countries to overdraw water from rivers and aquifers and thus degrading already scarce water resources. Climatic variability in Northern Africa (rise of temperatures and low rainfall) will lead to approximately 22% of lack of sufficient water by 2050 [5], which will increase more the long periods of droughts in this region of the world [6].

The main objective of this chapter is to highlight drought and water stress in Northern African countries along with outlining the main approaches and methods applying to better water managing in every country of Northern Africa.

2. Population growth

Population growth is increasing number of people over time for a particular place, depending on the balance of births and deaths. Population in Northern Africa has grown from 55.65 million to 205.11 million people, the North Africa’s population is more than tripled in size between 1960 and 2021. Egypt is the highest population, with over 104 million people. In 2021, the total population of Libya was about 6,96 million inhabitants. It is the country in Northern Africa which has the lowest population (Table 1).

Regions	1960	2021
Egypt	26.63 million	104.26 million
Algeria	11.06 million	44.62 million
Morocco	12.33 million	37.34 million
Tunisia	4.18 million	11.93 million
Libya	1.45 million	6.96 million
Northern Africa	55.65 million	205.11 million

Table 1.

Northern Africa’s population 1960–2021 [1].

In Northern Africa’s region, population growth increases because the fertility rate exceeds the death rate and thus water consumption is increasing inexorably through a combination of different water uses (drinking purposes, irrigation and other humans uses) and will further limit the freshwater availability per person. The most water scarce areas in Northern Africa are typically those, with limited source of freshwater and highest population density (the number of individuals per square mile or in square kilometers of land area), where people are currently unable to meet their basic water demand.

3. Drought and water stress in Northern Africa

Northern African region is characterized by considerable demographic growth. Northern Africa has hot semi-arid and arid desert climates and low rainwater. This region is predicted to face rising temperatures and decreasing rainfall. The recurrent droughts whose frequency has increased over the past 40 years can lead to water stress situations. While the overexploitation of available natural water reserves can exacerbate the consequences of droughts and thus leading to high depletion in its groundwater reserves.

3.1 Egypt

Egypt’s climate is extremely dry and receives a very low amount of rainwater because Egypt is predominantly desert [7]. Water resources in Egypt are limited and around 98% of Egypt’s water reserves originate outside of its borders. Main Egypt’s freshwater reserves are the Nile River which provides the region with around 93% of its water demand, precipitation, and ground water [8]. Climate change and its effects (droughts) in Egypt are predicted to make more stress on water reserves.

Nile River - Because the rainwater in Egypt is very scarce, more than 95% of Egyptians live along the Nile or in its teeming delta for all water needs. However, the Nile River’s land is threatened by climate change vulnerability which is expected to rise the frequency and intensity of floods and drought incidences in Egypt. Actually, the Nile River is predicted to decline by 40−60% of its current flow. Therefore, agricultural areas in Egypt have been subject to extensive and increasing water scarcity [9].

Rainwater – Egypt’s agricultural land is concentrated in a narrow strip along the coast where more amount of rainfall, and continuously declines southward [10]. Egypt has a mild winter season in the form of scattered showers along coastal areas. The mean annual rainfall is between 0 mm in the desert to 200 mm in the north coastal region with an annual average of about 12 mm. The total amount of rainwater may reach 1.8 billion m³ per year [11]. It is predicted that the mean annual precipitation will decline not only in Egypt but also in almost Mediterranean African countries. Furthermore, changes in precipitation patterns combined with sea level rise may further lead to decline in agriculture production and cause more stress on Nile River.

Groundwater is a vital resource especially in desert areas, besides providing drinking water groundwater is used for irrigation to grow crops and also has several other purposes. Groundwater ranks as the second source of natural water resources, after the Nile and constitutes around 12% of water supplies [12]. Egypt’s groundwater aquifers are considered a non-renewable resource and they are of variable importance for exploitation. The increasing demand for Egypt’s water reserves has placed groundwater resources under widespread pressure subjecting it to several issues such as depletion of its water quantity and degradation of its water quality. Different human activities such as the seepage of rainwater, irrigation and drainage and other effluents commonly affect not only the quantity of groundwater resources but also its chemical water quality [13]. On the North Coast of Egypt, there is a threat of saltwater intrusion into coastal aquifers which is caused by water withdrawals from coastal aquifers and up-coming near coastal discharge/pumping wells. On the other hand, Egypt faces several serious risks from climate change that impacts almost Egypt’s groundwater recharge rates and thus affects the availability of fresh groundwater (decrease in amount of precipitation and overexploitation of aquifers).

3.2 Algeria

Algeria is the biggest country in Northern Africa. The southern region forms about 80 per cent of Algeria’s land which is almost entirely the Sahara Desert with an arid climate. However, the northern part of Algeria’s territory is less arid. More than 34% of Algerian people are living in rural areas and most of them are concentrated in coastal zone [14]. During the past century, Algeria has been subject to frequent periods of drought which has clearly led to the degradation of the water reserve (quantitative and qualitative) in northwestern and central plains. Thus, these droughts have an adverse impact on meeting the water needs of all socio-economic sectors especially agriculture; posing a significant risk to farms and leading to yield reduction.

Rainwater - Temperatures in Algeria rise during the last decades and can become more acute than expected, with an important decrease in annual rainfall, sometimes various persistent droughts. Reduced rainfall is about 18 to 27% and the dry season has increased by two months during the last century [15].

Groundwater - The rainfall deficit has resulted in a decrease in the water volumes stored in dams. This situation of insufficient freshwater to satisfy requirements and droughts events in Northern Algeria continue to cause significant risks and widespread pressure on most aquifers; resulting in groundwater-level decline which may reach around 20 m or more in certain aquifers [16].

3.3 Morocco

Climate is varying considerably across Morocco’s northern to southern areas. The northern coast-central areas have Mediterranean climates characterized by hot, dry summers and cool, wet winters. At high-altitude locations, the climate is humid and temperate. In the south and west parts, the climate is Saharan. Droughts are becoming more frequent and severe in Morocco and impact negatively water resources and agricultural production [17]. Mean annual temperature has increased by 0.8°C (1960–2005) [18].

Rainwater - Morocco is commonly characterized by extremely high spatial−temporal rainfall variability. The northwest part of Morocco receives more precipitation than others. The mean annual precipitation varies considerably; the relief areas can receive approximately 800 mm of rain per year. Nevertheless, the adjacent plains areas can extremely receive 300 mm of rainwater per year [19]. Due to climate variability observed over the past decades in Morocco (1960−2005), Mean annual rainfall has decreased with an amount ranging between 3% and 30%, with a drop of 26% in the north-western region of the country [18]. In fact, Morocco suffers from its worst drought over the past 40 years with low precipitation resulting in at least ~50 per cent overexploitation of aquifers.

Groundwater stretches more than 80,000 square kilometers and represents around 20% of Morocco’s water reserves [20]. Morocco has ninety-six aquifers, twenty-one of which are deep and seventy-five shallows. Morocco faces its worst drought in last four decades resulting in (1) decline in rainfall, (2) decline in River flows which reached approximately 20% within the periods 1970–2006 and 1950–2006 and more than 70% in certain parts of Morocco and also (3) depletion of groundwater aquifers [21] ranging between 0.5 and 2 m per year (low groundwater recharge and over-expansion of agricultural activities) [22]. The Mikkes basin is an example of Moroccan basin. It is situated in the North-central of Morocco and had a high depletion in its water reserves: a rainfall deficit reached 76% (1970−1979 and 1980−2000); this high rainfall deficit had led to overexploitation of Mikkes aquifers and thereby springs and River flows depletion [23, 24, 25, 26, 27]. Furthermore, Morocco’s aquifers groundwater quality assessment shows a deterioration, as a result of combined pressures of climate change (seawater intrusion) and human activities (nitrate pollution).

3.4 Tunisia

Tunisia is situated between Algeria (on the west and southwest) and Libya on the southeast (Figure 1). Tunisia’s climate varies with location: The north region is with a sub-humid to semi-arid climate. The central part is with semi-arid to arid climate and the southern part has a desert climate. Tunisia is vulnerable to climate change resulting rise in temperature, a reduction in rainwater and sea level rise. Over the past decades, temperature increased by approximately 0.4°C per decade. In southern Tunisia, droughts become increasingly more intense and frequent, while Tunisia’s Mediterranean coast has been treated with rising sea level and flooding [28]. Between 1900 and 2000, the mean annual temperature increased by around 1.4°C [29].

Rainwater - As Tunisia is bound on the northeast by the Mediterranean Sea, on the south - the southwest by the Sahara (Figure 1), the precipitation is variable from the north to south and from east to west. Northern Tunisia is the rainiest part as mean annual rainfall reaches more than 400 mm in the extreme north and 1500 mm in the extreme northwest. However, the centre of Tunisia has average precipitation ranging between 150 and 300 mm [30]. The Tunisian southeast is characterized by an arid Mediterranean climate, with average precipitation varying between 100 and 200 mm per year [31]. Actually, precipitation amounts have changed in Tunisia during the 20th century and the region has experienced several severe droughts. Since the fifties, the annual totals of precipitation have declined by 0.5% per year in northern Tunisia [32].

Groundwater - As Tunisia has been suffering from increased recurrent and frequent droughts which led to high rainwater decline. Many farms rely on wells (groundwater) to fulfil their water needs. This will most likely extend to the over-use of groundwater resources where many aquifers are already experienced; putting more pressure on groundwater means that the rate of pumping is greater than the rate of infiltration. Consequently, the level of certain aquifers drops so much and thus many wells run dry. Actually, by 2030, the overexploitation of Tunisian coastal aquifer (due to agricultural activities) will drop from 28% [33] and 50% of coastal aquifers and will be salinized due to sea-level rise [34]. Therefore, this country needs urgent and practices approaches for better water management to avoid more water reserve deteriorations.

3.5 Libya

Libya is a country located in North Africa and it is the fourth-largest one in all African continents (Figure 2). About 95% of Libya consists of desert (the Sahara) and under 2% of the land is arable. Libya has two distinct climates: One in the south is characterized by hot arid Sahara climate and the other is influenced by the Mediterranean Sea resulting moderated climate. Climate change has many effects including rising temperatures and more severe frequent droughts and floods. The limited natural resources (water and soils), the desert lands and the drought events are all the main drivers which will force Libyan farmers to abandon their farms amidst water stress and therefore the yields of rainfed agriculture will be severely low.

Rainwater - Libya is one of the driest regions on Earth with no permanent rivers flowing through its boundaries. About 96% of Libyan land surface receives annual precipitation which cannot reach an amount of 100 mm. Less than 2% of the Libya region receives enough rain to support agriculture, and only a narrow ribbon along the coast receives more than 100 mm of rain per year. Furthermore, the effects of global climate change in Libya include more rising in temperatures, a drop in precipitation amount which is already very low and prolonged period of droughts which will produce increased aridity. For the 66 years (1945−2010), temperature data in Libya showing that the mean annual temperature has risen [35].

Groundwater freshwater reserves in Libya originate from 4 aquifers: Kufra, Sirt, Morzuk and Hamada that provides over 90% of Libya’s water. These aquifers are likely to be even more important as drought increases and rainfall decreases. Increase in drought tendency is a principal factor in lack of rainwater (or water availability). This water scarcity is expected to cause more aquifers depletion (quantitative and qualitative) in the region. The intensive extraction of groundwater (GW) in coastal aquifers is causing a reduction in the availability of freshwater outflow to the sea and creates local water table depression, causing saltwater intrusion [36], resulting in deterioration in groundwater quality.

4. Agriculture

Northern Africa is reported to be among the world’s most water-scarce regions where drought is a principal climatic factor (rising temperature and drop in rainwater) reducing agricultural production [37]. Agriculture is the most vulnerable economic activity. It is considered as a major challenge in Northern African countries, particularly for farmers whose livelihoods rely on rainfed farming. Farmers in Northern Africa have to increase crop production to meet the rising needs for food.

Egypt is predominantly desert, with only 4−5% of land used for the Egyptian people to live and produce food [38]. Egypt is a water-scarce country (with less than 1000 m³ of freshwater per year) and it is near the edges of absolute water scarcity (less than 500 m³/year). Agriculture plays a significant role in the Egyptian economy as it is the sector which plays a crucial role in food’s productivity. This sector provides livelihoods for about 55% of Egypt’s population, which is largely rural [39]. Agriculture consumes between 80 and 85% of water resources. More than 90% of River Nile water goes towards agricultural productivity. As Egypt’s population still grows, the economy is expanded and significant drought severity, all these drivers and others are contributing together to more growth in freshwater demand and render the whole of the Nile valley vulnerable. Since water availability (quantitative and qualitative) is the major factor of agricultural production, the Egypt authority needs a sustainable water strategy to better ways of resolving the shortages of water and is through good agricultural water management.

Algeria is a poor country in water resources because of the irregularity (insufficient and unequally distributed) of water supplies. The annual water supplies drop below 1000 m³ per person. Agriculture is the largest using sector of water and is increasingly subject to water risks. Almost 25% of the Algeria population is engaged in agriculture sector. Water demand is predicted to further increase because of population pressures increase, intensive agriculture, economic growth and high drought risk under climate change. Thus, developing a mix of strategies that increase water supplies, manage water demands, and reduce long-term pressure on water is urgent more than ever before.

Morocco - Agriculture represents almost 15% of Morocco’s GDP [17]. Agriculture is the primary user of water, accounting for 80 percent of withdrawals. Morocco suffered severe water shortages under its worst drought in 4 last decades and which is prompted by expansion in water needs (decrease in rainfall and bad water management). Morocco expects to reach absolute water scarcity (the annual water supply drops below 500 m³ per person) and people are expected to live under extreme water stress in less than 25 years [19]. Actually, various Innovative irrigation practices can help in reduction of water uses in agriculture. Nevertheless, they are expensive for small farmers to afford.

Tunisia is one of Northern African countries suffering from water stress as it has limited surface water reserves, low precipitation and thus a great increase in agriculture’s dependence on groundwater withdrawal. As Tunisia’s population increased from 4.18 million (1960) to 11.93 million (2021) (Table 1) and also drought frequency so all these factors and others have drastically increased food needs to be grown, which requires more water. About 80% of Tunisia’s freshwater resources are used for agricultural exploitation; Over 76% of groundwater is used by agricultural sector. However, less than 24% of irrigation water use come from surface water [40]. Tunisia witnessed its worst drought in 50 years from 1999 to 2002, which caused more increase in water consumption and affected agricultural producers [41]; resulting in deterioration of the quality and quantity of groundwater reserves.

Libya is the second-largest country in Northern Africa, and it is almost entirely covered by the Libyan Desert (Figure 2). Thus, most residents of Libya live in the coastal regions where more chance of water availability. Groundwater constitutes the major freshwater supply in Libya [42] and it constitutes around 98% of the total freshwater demand [43]. Irrigated agriculture is also the largest using sector of freshwater; it consumes more than 80 percent of freshwater. The shortage of clean and freshwaters in Libya have led to an overall situation of overuse of groundwater. During the last 4 decades, the irrigated land has increased considerably which is causing more pressure on water availability which is already very stressed.

5. Managing drought and water stress in Northern Africa

Water stress is a growing problem worldwide. In Northern Africa, the demand for water is likely to increase while water supplies are reduced. This is driven by a combination of the rising population (coupled with economic growth) and more frequent periods of droughts which the region recognized especially over the last 4 decades, rendering water availability in the future uncertain. Groundwater tends to be over-exploited and polluted to meet growing water consumption. Water stress and drought situations around Northern African countries constitute widespread two major phenomena (natural and human-made) that challenge water security, hence, all need to work together for better solutions of water issues as such, i.e., reuse of drainage wastewater, water desalination and rainwater Harvesting (RWH).

5.1 Reuse of drainage wastewater

Rising population and long period of droughts exerted high pressures on renewable freshwater resources in Northern Africa over the last decades. This will lead to markedly greater competition between urban areas and farmland for water and thus producing more wastewater. Actually, the reuse of drainage wastewater is a great way to help protect the environment by reducing dependency on freshwater and meeting rising water consumption. Wastewater treatment is a process used to remove contaminants, micro-organisms and other types of pollutants from wastewater or raw sewage and convert it into an effluent that can be returned to the water cycle. Reusing wastewater is an obvious solution for the future to reduce water shortages in several regions on the Earth such as Northern Africa. After treating sewage, the treated wastewater can be reused for several applications such as irrigation purposes.

Egypt – Egypt’s freshwater resources are limited. The gap between freshwater demand and supply is intensified by various combined factors including rising population and drought frequency. Reuse of sewage effluent in agriculture represents an opportunity that can alleviate the water stress on limited natural water reserves in Egypt. This process started in 1920 [44] and it is relatively less-infrastructure requirements to be constructed and cheaper option. The 1975 water policy for reuse of wastewater discharge had a target to decrease water stress on the Nile system and hence to increase cultivated areas and meet Egypt’s growing food. Currently, this system is broadly applied in Delta region and produces approximately 4.0 BCM/year of wastewater discharge to be mixed with the freshwater of main canals. The Government’s Planning for the Future is to reuse an additional 3 BCM/year. Besides these benefits, it deserves consideration of some disadvantages including the use of untreated wastewater for crop irrigation can also cause soil hardening and shallow groundwater contamination [45]. Therefore, Egypt started using treated domestic sewage wastewater treatment systems which will increase water recovery from wastewater and meet environmental regulatory requirements and thus protect freshwater bodies and biodiversity. SUEZ is providing Egypt with different types of sewage treatment plants including that of Gabal El As-far, on the eastern bank of the Nile [46].

Algeria - Over the past 4 decades, Algeria has experienced water stress which becomes acute due principally to high population growth rates, long periods of droughts and bad water management. The reuse of treated sewage effluent represents a valuable solution to conserve natural resources and reduce the consumption of freshwater, especially in the agricultural sector. In 2005, Algeria started using treated wastewater as alternative resources that are able to satisfy the needs of water demand in agricultural sector and promote the coordinated development of integrated water management systems [47]. At present, Algeria could indirectly improve water supply and increase water availability by reusing around 484 Hm³ of wastewater, among which only 425 Hm³ are subjected to water treatment (removes contaminants and undesirable components). The rest simply undergoes dilution in the natural environment [48].

Morocco is highly susceptible to prolonged shortages in the water supply (droughts). To reduce the impact of drought and population growth on water consumption, the Morocco government has adopted a series of legislative measures and institutional reforms to better Integrated Water Resources Management (IWRM). Since 1960s, the country has contributed significantly to the mobilization of its hydraulic capacities. Applying treated sewage effluents (TSE) in agricultural irrigation in regions suffering from water scarcity like Morocco is a non-conventional water reserve to alleviate water stress and help in saving freshwater for drinking and for improving crop productivity. Thus, a necessity for a better water resources economy, only the rate of about 12% of treated wastewater is currently recycled but this rate reached 22% in 2020 and may achieve around 100% by 2030 [49].

Tunisia is suffering from high water stress due to many contributing drivers including the region has a Mediterranean arid climate. Tunisia’s water reserves are limited. Tunisia is highly vulnerable to the adverse effects of climate change (increase in temperatures and aridity with decreasing rainwater). Actually, Tunisia is determined to promote wastewater reuse and satisfy its water demand for agricultural sector and other uses and this through many ways including improving the status of existing water resources, reducing the effluent of wastewater treatment plants to the sea and raising awareness. The government policy strongly supports sewage treatment plants and incentivizes wastewater reuse. In 2009, around 63 Mm³ have been reused directly for irrigation and the total agricultural area equipped with sewage treatment plants was around 8065 hectares [50].

Libya is facing extremely high baseline water stress. With the rising population and demands for freshwater, reusing wastewater is an increasingly sustainable and acceptable practice to satisfy water needs. Thus, Libya government is increasing efforts to enhance wastewater treatment plans in order to cope with water scarcity in the region and generate sufficient water, especially in irrigation. There are about 23 wastewater treatment plants in Libya but only 10 of them are working and in operation [51].

5.2 Water desalination

Seawater desalination is the process of changing seawater or brackish into usable water or pure water by which the dissolved mineral salts in water are removed. Northern African countries are suffering from water shortages for agricultural purposes and other uses. So, there are alternative potential water supply sources to meet growing water needs. Desalination is among the most sustainable alternative and extreme solutions that can solve water stress issues in Northern African countries, although it is an energy-intensive process that can be very expensive.

Egypt has the following coastlines: Northern coastal border is on the Mediterranean Sea and east coast border is on the Red Sea. This country is using seawater desalination as a major and sustainable source of water supplies and development (abundance of energy). However, this practice has been given low priority because it is affected significantly by many different factors including water quality, technical application and methods, energy-consuming, plant capacity and plant availability [52]. The capacity of desalinated water in Egypt is approximately 0.03 BCM/year [53]. Additionally, the Egypt authority has involved both sectors (the public sector and the private one) to work together to a better agricultural water resource management through applying modern technologies for desalination such as distillation, reverse osmosis (RO) and electrodialysis.

Algeria - Desalination plants provide water that can be safe to use in irrigation. Algeria is using desalination as a viable resource during the intense time of drought. In fact, it is a great practice in Algeria as it can relieve water stress for irrigation purposes and also for other water uses for daily processes. Reverse osmosis technology is the most convenient and effective filtration method used for desalination that represents approximately around 95% [54].

Morocco - Water desalination is practically a solution for Southern Moroccan; most part of inhabitants suffers from shortages of potable water and inadequate precipitation. The following of some Southern Moroccan cities which adopt these water desalination solutions: Boujdour has used Multi-Effect Distillation and also Mechanical Vapor Compression solutions to provide a total capacity of around 250 m³/d and Boujdour has used Sea Water Reverse Osmosis solutions to provide a total capacity of around 800 m³/d. Laayoune has used Sea Water Reverse Osmosis solutions to provide a total capacity of 7000 m³/d [55].

Tunisia and especially the centre and south parts of it are suffering from water scarcity and droughts periods as the low rainfall. Water desalination for irrigation seems to be a promising solution to fulfill the increased demand for freshwater. The four major desalination plants have been inaugurated to help are Kerkennah (1983) with a total desalination capacity of 3300 m³/day; Gabes (1995) with 22,510 m³/day; and 2 stations in Jerba-Zarzis (1999) with 12,000 m³/day. Furthermore, there are sixties smaller plants used to help in providing water for industry uses [56].

Libya faces severe water stress problems caused mainly by the limited freshwater bodies and also drought. Water desalination is a particularly advantageous alternative freshwater source that can reduce water stress in Libya. Since the sixties, Libya has been using desalination because of its an increasingly viable alternative as it is regarded as an extreme solution for water supply. In addition, this desalination technology is widely implemented to produce freshwater over the past decades to meet the increasing demands of water for irrigation purposes and other uses. Currently, Libya has 21 operating desalination plants with a capacity of 525.680 m³/d [57].

5.3 Rainwater Harvesting

Many people in different areas of the world such as Northern Africa suffer from lack of access to safe and clean drinking water. To have access to safe potable water, huge investment costs and expenditures are needed. Roof-water or RWH is a method of collecting and conserving rainfall for future usage. The harvested water can be stored, utilized in various ways or directly used for groundwater recharge. Roof-water is an old method that has been adopted in different regions on the Earth and especially Northern African region [58]. RWH is a viable solution to help meet the growing demand for water. It can improve water productivity by collecting rainwater from impermeable surfaces (rooftops) and storing it in containers (tanks or cellars) for future uses. Additionally, RWH helps in reducing floods and soil erosion and may reduce agricultural drought risk.

Egypt – In Egypt, natural water reserves are limited. Actually, Egypt is under water stress, a problem that can be partially alleviated to meet people’s needs by using RWH as good alternative to non-conventional water resources. High potential of RWH was built in Northern Egypt including Alexandria city which can help in reducing water usage home and can satisfy approximately 12 percent of its future supplementary domestic purpose. Nevertheless, in the central – south part of Egypt, the precipitation is irrelevant to be harvested [59].

Algeria - Water is naturally scarce in Algeria because of the following factors: very low rainwater, human growth considerations, droughts and thus water demand is continuously increasing. Using rainwater harvested in Algeria from houses roofs appears a great sustainable promising solution to lack of water and droughts to satisfy water needs in areas where rainfall is uneven or unequal, such as in Souk Ahras city.

Morocco has adopted fog water harvesting system-based NGO Dar Si Hmad as the most promising alternative system for sustainable freshwater resources management to minimize the shortages of water. This system is the world’s largest operational fog-water harvesting system. It delivers a good solution for hundreds of rural residents who are suffering from water shortages to satisfy their basic water needs [60].

Tunisia - RWH is a solution to help reduce freshwater consumption by utilizing – rainwater from the roof. It is a satisfactory alternative practice in southeast Tunisia which suffers much from water shortage (mean annual precipitation values from 100 to 200 mm). The Tunisian authority promotes many water harvesting techniques including surface runoff water harvesting, floodwater harvesting and spreading irrigation [4].

Libya has consistently suffered from water stress and droughts. RWH is one of the major options to provide more water. RWH is a sustainable way in Libya’s coastal part that can deal with shortages of water and meet the increasing water demand (clean water).

6. Conclusion

Northern Africa is one of the world’s most water-scarce regions. The freshwater resources in Northern Africa region are limited. Due to many factors including population growth, recurrent and frequent droughts over the last 4 decades and poor freshwater management, water demands will increase to satisfy different human uses such as irrigation purposes. Thus, water scarcity in the region is going to increase in future years and be more worsen. Hence the need to embrace the best water managing demand and through several unconventional water resources such as reuse of drainage wastewater, seawater desalination and rainwater harvesting. Indeed, managing water scarcity in Northern Africa in a sustainable, efficient, and equitable ways is paramount to tackling Northern Africa’s water stress.