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The catchment of the Dead Sea covers approximately 42,000km2, stretching from southern Lebanon to the Sinai Peninsula in Egypt (see map below, the area bordered in white). All rainfall in this area that is not evaporated or extracted for use elsewhere accumulates in the Dead Sea, a low-lying saline lake. Because the catchment of the Dead Sea is an inland basin – it has no outlet to the sea – all the incoming water must evaporate from its surface. For the Dead Sea to maintain a constant water level, the amount lost by evaporation must equal the inflowing water. However, the Dead Sea has been shrinking because its main source of water, the Jordan River, has been gradually declining since the 1950s as a result of large-scale water infrastructure projects on the river and its tributaries. The Israeli and Jordanian development of the potash industry in the shallow southern part of the sea has further contributed to its decline. In 2014, the level of the Dead Sea had dropped to 428 metres below sea level (m bsl), which represents a drop of 30m since 1960. As a result, the surface area of the Dead Sea has been reduced by about a third from 950 to 620km2.
This decreasing water level (presently about 1.1m/yr) causes significant environmental damage, including the loss of freshwater springs, riverbed erosion and the development of more than 3,000 sinkholes. In addition, the unique ecosystem of the Jordan River basin, critically important to migratory birds, is under threat.
The shrinking of the Dead Sea also harms the potash industry and tourism suffers as the distance between hotels and the seashore increases. In order to rehabilitate the Dead Sea and develop additional water resources, Israel, Jordan and the Palestinian Authority signed an agreement in 2005 to develop a water transfer project from the Red Sea to the Dead Sea. The objectives of the project were:
- To save the Dead Sea from environmental degradation;
- To generate hydroelectric power;
- To desalinate water;
- To build a symbol of peace in the Middle East.
Israel, Jordan and Palestine requested that the World Bank manage the implementation of a study programme and coordinate donor financing. The study programme was completed in 2013 and resulted in five reports:
- Feasibility study;
- Environment and social assessment;
- Study of alternatives;
- Red Sea modelling study;
- Dead Sea modelling study.
The studies, which cost $16.7 million, were financed by France, Greece, Italy, Japan, The Netherlands, South Korea, Sweden and the United States.
The feasibility study estimates the total costs for the preferred pipeline option at $10.6 billion, which includes an annual extraction of 2 billion cubic metres (BCM) from the Red Sea, two hydroelectric power plants and a reverse-osmosis desalination plant. No proposals were made for the financing of the project.
In December 2013, the three parties signed an agreement for the implementation of a vastly scaled-back version of the Red Sea-Dead Sea (RSDS) Project. It is designed to accomplish two objectives: to provide new water to a critically water-scarce region; and to understand better, under scientific supervision, the consequences of mixing Red Sea and Dead Sea waters. According to the agreement, 200MCM/yr will be extracted from the Red Sea for the production of 80-100MCM/yr of potable water at Aqaba. Israel will receive 50MCM/yr of water for the Arava region and Eilat, and Jordan will use 30MCM/yr in the southern region of Aqaba. In return, Israel will make available to Jordan 50MCM/yr of water from Lake Tiberias for use in the north. About 100MCM/yr of brine from the desalination plant at the Red Sea will be transported through a 200km pipeline to replenish the shrinking Dead Sea. This is about one tenth of what is needed to prevent the level from dropping further. The $950 million project is to be financed through international funding. The pipeline will take an estimated three years to complete.
Shrinkage of the Dead Sea between 1972 and 2011
Geographic setting and natural conditions
The Dead Sea is part of the Jordan Rift Valley (JRV), which extends from Lake Tiberias in the north to the Gulf of Aqaba in the south. The bottom of the Dead Sea is, at 790 metres below sea level (m bsl), the lowest point in this valley and the shoreline, at about 420m bsl, is the lowest land surface on earth. The shores on the eastern and western sides of the Dead Sea rise sharply, to about 1,000m over a distance of 15-20km. This striking topography developed because the JRV is an active tectonic boundary of the Arabian Plate. The Dead Sea Transform Fault is characterized by both spreading and lateral movements along the JRV. This results in a considerable risk of earthquakes. In spite of the absence of seismic activity for the past 500 years or so, this risk has a large influence on the structural design and cost of the RSDS Project.
During the Pleistocene period, the JRV was covered by one large lake that extended from Lake Tiberias to some 35km south of the Dead Sea. The highest water level (180m bsl) was reached around 25000 BCE. The sediments deposited at the bottom of the lake are marls, consisting of loam and calcareous silt loams which are mixed with salts and gypsum. These formations are known as Lisan deposits. The land tongue that now separates the deep northern part of the Dead Sea from the shallow southern part where the potash industry is situated is known as the Lisan Peninsula (from the Arabic word lisan, ‘tongue’). Below these deep alluvial deposits, the underlying rocks are faulted by the tectonic activities along the JRV.
The Dead Sea region is of major historical, cultural and religious significance and includes important archaeological sites. With its therapeutic spas and healing waters, the Dead Sea attracts many local and international tourists. The RSDS Project area also includes sensitive regions (e.g. for migratory birds) and nature reserves (e.g. the Dana Nature Reserve).
The area between the Dead Sea and the Red Sea is sparsely populated, with densities of 10 to 50 inhabitants per km2 or less. The main population centres are located in the Aqaba/Eilat area and on the shores of the Dead Sea.
The climate is subtropical, with maximum temperatures varying from 40oC in July to 23oC in December and minimum temperatures from 30oC to 13oC. The average annual rainfall is less than 50mm, and the average number of rainy days is about 15. At 400m bsl the atmospheric pressure is 5% and the oxygen content 4% higher than at sea level, while there is less solar ultraviolet radiation. Modelling and desk studies of climate change suggest that, by 2100, the average temperature may rise by 3-6oC and the precipitation may decline by 30%. The greater intensity of rainfall events may also result in a 30-50% decrease in runoff and aquifer recharge by 2100. However, like other wadis draining directly into the Dead Sea, the side wadis that flow into Wadi Araba/the Arava Valley south of the Dead Sea are prone to occasional large flash floods. These floods strongly influence the design of RSDS Project infrastructure.
Until 1978, the Dead Sea was composed of two stratified water layers with different temperatures and salinities (meromictic state). However, in the winter of 1978-79, a complete turnover occurred, when the density of the upper layer became greater than that of the lower layer. Presently, seasonal stratification results in an annual turnover, creating a monomictic state of the Dead Sea. The homogeneous water contains 343 grams per litre (g/L) of dissolved salts and has a density of 1240g/L. Compared to sea water, Dead Sea water is richer in chlorides (Cl), sodium (Na), potassium (K), magnesium (Mg), calcium (Ca) and bromide (Br) and is deficient in sulphates (SO4). The chemical industry annually extracts 650MCM from the Dead Sea and returns 250MCM of brine. It appears that this activity changes appreciably the chemical composition of the Dead Sea by increasing the concentrations of Mg, Ca, Cl and Br, while the concentrations of Na, K and SO4 are decreasing. Recent indications suggest that the very saline and dense deep layer formed by chemical industry return brines will continue to develop.
In addition, the hydrodynamic equilibrium between the surrounding fresh groundwater and the salt water of the Dead Sea has been affected by the decline in water levels. The interface between the two has begun to readjust to a new equilibrium state through a seaward movement of the fresher groundwater. Accordingly, groundwater levels in the surrounding areas have dropped, as large amounts of fresh and brackish groundwater have flowed into the Dead Sea in partial compensation for its declining level.
Outcome of the feasibility study
The feasibility study was carried out under the auspices of the World Bank by the engineering consultancy Coyne and Bellier. According to the terms of reference, three scenarios were examined:
- The No Project scenario;
- The Base Case scenario, to stabilize the level of the Dead Sea only;
- The Base Case Plus scenario, to stabilize the level, desalinate water, and generate power.
The mass balance of Dead Sea water was established for the year 2010, as illustrated in the diagram below. It shows that the net water loss from the Dead Sea is about 708MCM/yr, which corresponds to an annual decline in the water level of 1.1m. The study predicts a nearly linear fall in the level, but, if the chemical companies cease to operate, a new equilibrium will be reached around the year 2150 at a level of about 550m bsl. This No Project scenario would have detrimental effects on the environment, the chemical and tourist industries and infrastructure such as roads and buildings.
Assuming that the project will be commissioned in 2020, the Base Case scenario for a target water level of 410m bsl requires an initial flow rate of 2,000MCM/yr and from 2050, when the target level is reached, a reduced flow rate of 1,520MCM/yr. The latter value is much larger than the deficit of 708MCM/yr shown above, because of higher evaporation rates from the less saline surface layer and the effects of climate change.
The potable-water requirements agreed upon for the Base Case Plus scenario are shown in the bar chart below. For a potable-water production of 850MCM/yr, about 2,000MCM/yr of seawater are required. This is based on reverse osmosis, in which Red Sea water is forced through a semi-permeable membrane to yield fresh water, leaving behind highly saline brine.
The non-potable brine is conveyed to the Dead Sea. The volume pumped to the Dead Sea changes from 1,650MCM/yr (with less than 30% brine) in 2020 to 1,150MCM/yr of pure brine in 2060. The Dead Sea water mass balance model, which takes into account climate change, shows that, for a seawater extraction rate of 2,000MCM/yr, the Dead Sea level will peak at around 416m bsl in 2054, when the desalination plant reaches its ultimate design capacity. Beyond 2054, the level is projected to fall at a rate of 15cm/yr to reach a stable level of 431m bsl in 2150. This decline results from increased evaporation due to a continuous decline in salinity.
From 15 possible conveyance configurations to transport water from the Red Sea to the Dead Sea, three were selected for more detailed evaluation:
- A gravity-flow conveyance tunnel constructed at zero elevation;
- A pumped conveyance, a combination of tunnels and canals, rising to 220m asl;
- A pumped pipeline configuration rising to an elevation of 220m asl.
The optimum location of the hydroelectric power plant is at the northern end of the conveyance, close to the Dead Sea. Two alternatives have been examined:
- A high-level desalination plant operating in series with the hydropower plant. This configuration minimizes the pumping head required for delivering the potable water but reduces the hydrostatic head available to drive the reverse osmosis. The water available for the power plant diminishes with time and, in 2060, will consist exclusively of reject brine from the desalination plant.
- A low-level desalination plant operating in parallel with the power plant. With this configuration, the maximum hydraulic head is used to drive the reverse osmosis, but a lot of energy is required to pump the potable water to the consumers. Moreover, in 2060 almost all of the water will go to the desalination plant, leaving very little flow available to the power facility.
The flow of water available for power generation diminishes with time. An economic evaluation demonstrates that full capacity should be installed from the start, resulting in surplus capacity in later years. Simulation of six different system configurations for the period 2020 to 2060 shows that the best option is one power plant at the high-level desalination plant and another at low level.
The feasibility study also examined three different intake locations on the Red Sea and the alignment of the discharge channel from the power plant to the Dead Sea.
A multi-criteria comparison of all viable options has shown that the pipeline conveyance system with a high-level desalination plant is the preferable option. With a capital expenditure of $10.6 billion, it is also the least expensive.
The outcome of the feasibility study of the RSDS project may be summarized as follows:
- Feasible from an engineering perspective;
- Positive economic return (due largely to intangible benefits);
- Large net consumption of energy (803MW by 2060);
- Eastern intake in the Gulf of Aqaba preferred;
- Buried pipeline preferred over tunnels and canals;
- Desalination plant best located at a high level close to the Dead Sea;
- A small-scale, stand-alone pilot project could be implemented simply and quickly.
Description of the recommended option
The recommended optimum solution is a pipeline for the transfer of 2,000MCM/yr of water from the Red Sea. The intake consists of a submerged pipe off the eastern shore of the Gulf of Aqaba. More research is required to determine the optimal depth of the intake (between 25 and 140m). Fourteen pumps, each with a capacity of 15 megawatts (MW), will be installed. The pump station has a gross pumping head of 273m and a capacity of 64.7 cubic metres per second (m3/s). The energy requirement for the pumping station is estimated at 1,920 gigawatt hours per year GWh/yr. From the pumping station, there is a 25.5km rising tunnelled section. The tunnel will have a steel lining and an internal diameter of 5.5m. Construction of a much shorter (straight) tunnel requires additional geotechnical investigations. Such a tunnel could be $500 million cheaper. The transfer continues through six buried steel pipes, each with a diameter of 2.9m over a distance of 66.5km to the water divide of the Dead Sea basin, known as the Gharandal saddle. At this highest point in the route (220m asl), a 175,000m3 balancing reservoir will be constructed. The 84km gravity-flow conveyance consists of three parallel pipes, each with a diameter of about 3m. Special arrangements will be made to accommodate a small degree of rotation and longitudinal deformation of the pipes in areas where the pipeline crosses active faults in this seismically active area. Provision will be made for the detection of insidious small-scale leakages, which may occur undetected, while in-line isolation valves at regular intervals will minimize the impact of large catastrophic leaks.
The natural location for the desalination plant would be at the balancing reservoir, but this would require long supply lines for the potable water. A location downstream of the gravity section, at a lower elevation, provides an optimal balance between the shorter length of the potable water transmission lines and the extra pumping head needed. Of the better-established desalination technologies, reverse osmosis was considered economically viable for large-scale seawater plants in the absence of surplus heat from other industrial processes such as power generation. The quality of the seawater is generally good, so pre-treatment can be limited to multimedia filtration. A balancing storage facility for the desalinated water, with a maximum capacity of 250,000m3, will be provided at the plant’s outlet.
Two hydroelectric power plants will be constructed, one (113.8MW) at the high-level desalination facility and the other (135MW) immediately south of the chemical industry solar evaporation ponds, close to the village of Feifa. This lower site will also accommodate the incoming penstocks (enclosed pipes that deliver water to the turbines), an energy dissipation basin (for use in the event the power station must be shut down) and the outgoing discharge canal.
A two-metre-high dyke will protect the location from flooding. The best route for the conveyance of water in a canal from the power plant to the Dead Sea (the restitution canal) was determined to lie between the two sets of evaporation ponds.
The energy balance of the recommended option is summarized in the figure above. The energy consumed includes that required for pumping the potable water to Amman but not to Israel or Palestine. The high-level desalination plant requires about 3.2 kilowatts for the production of one cubic metre of potable water.
Environmental and social impacts
The most worrying potential impacts of the project on the Dead Sea are:
Changes to the layering, stability and circulation of the water body. It is expected that the project will not affect the horizontal circulation patterns but that it will create a more stratified lake, with a 50m-deep surface layer consisting of less saline water. Below the surface layer, there will be little change in the highly saline and very dense deep layer, which will continue to extend at the bottom, due to the discharge of brine by the chemical industry.
Changes in chemical composition. In the long run, the surface layer will take on the characteristics of ocean water concentrated by evaporation. The chemical composition of the main body of water will probably continue to change, as it has during the last 50 years, as long as the chemical industry continues to operate.
Possible increase in the frequency and duration of red-algae blooms. The Dead Sea modelling study shows that, for a discharge of less than 400 MCM/yr of Red Sea water or ejected brine, the salinity will not fall below the threshold below which algal blooms can develop. For a discharge of 1,000 MCM/yr, the salinity will fall to the critical value below which bacteriological phenomena may begin to affect the Dead Sea.
Possible changes in the salinity and buoyancy of the surface layer. The density of the surface layer is currently 1,240g/L and will continue increasing, to 1,360g/L. During the project, the density will decline to 1,170g/L, which is slightly higher than the density 50 years ago.
The original project aims to mitigate environmental degradation of the Dead Sea, which includes:
- Decline of the Dead Sea level. The present rate of decline of 1.1m/yr will be stopped and the decline may, to some extent, be reversed.
- Creation of exposed mudflats and resultant windblown dust. Over the last 50 years some 30 km2 of seabed has been exposed. These mudflats are very unattractive to tourists, and their spread damages the tourism industry.
- Creation of sinkholes. A large number of sinkholes (more than 3,000) has suddenly appeared, destroying buildings, roads and agricultural land and limiting recreational and commercial activities.
- Decline of the groundwater table. With the fall in the level of the Dead Sea, the groundwater table in the vicinity has fallen and wells have dried up.
- Damage to infrastructure. Surface water channels draining to the Dead Sea have suffered erosion due to the falling level. Erosion has also caused extensive damage to both public and private infrastructure.
- Decline in tourism. Statistics show that there has been a decline in international tourist visits to the Dead Sea, which may be attributable to the degradation of the Dead Sea.
The social assessment shows that most of the negative impacts will occur during the construction period and arise mainly from the influx of foreign workers into a sparsely populated, poor and socially and religiously conservative area. On the other hand, there will be possibilities for additional employment. During operation, there will be some employment opportunities at the desalination and power plants. Other benefits provided by the supply of potable water will be felt mostly outside the project area.
Project costs, management and alternatives
Figure 7 shows the estimated costs of the option that was recommended in the feasibility study (buried pipeline and high-level desalination plant). These costs do not cover the connection of the desalination plant to the Israeli and Palestinian transmission grids. The second figure below shows operating costs.
The following governance structure is recommended for the management of the project:
- Intergovernmental treaty;
- Three governmental executive committees;
- Operating cooperation;
- Board of directors;
- Project management;
- Commercial management;
- Advisory board or expert panel.
The following alternatives are presented in the Study of Alternatives Report (2012):
The cost of the falling level of the Dead Sea has been estimated at $73-227 million/yr. The cost of producing potable water at Aqaba and transferring it to Amman is estimated at $2/m3, considerably higher than the cost of water produced through the RSDS Project (<$1.5/m3).
Restoration of the Lower Jordan River
Full restoration of the historic flow of the Jordan River (1BCM/yr) meets the first objective of saving the Dead Sea but is, at present, neither economically nor socially feasible. If, in the future, the supply of potable water increases to meet the needs of the growing population, there may be enough recycled water to restore the Lower Jordan River.
Transfer from the Mediterranean Sea
Two possible routes for the transfer of water from the Mediterranean Sea to the Dead Sea have been studied. The northern route enters the Jordan River just south of the Lake Tiberias. It is not considered feasible because of the risk of pollution of the groundwater system in this agricultural region. Of two possible southern routes, the one from Ashkelon to the northern tip of the Dead Sea was evaluated. This route intersects with groundwater resources in the Mountain Aquifer below the West Bank and is economically less viable because of the expense of the required pilot project.
Overland water transfer from Turkey
Almost 20 years ago, when the Peace Pipeline was proposed, it was assumed that there would be 2BCM/yr of water reliably available from Turkey, but Turkish officials now assert that this is no longer true. Moreover, political instability and violent conflict in the region make the viability of this option questionable.
Transfer from the Euphrates River
The transfer of reasonably high-quality water from the Euphrates River in Iraq would be technically and economically feasible, but the volume of water (60MCM/yr proposed in studies undertaken in the 1990s) would be too small to restore the Dead Sea. Political instability and violent conflict in the region also make the viability of this option questionable.
Many other alternatives were considered, including desalinating water at various locations, instituting water savings in the potash industry and in agriculture, conserving and reusing water, and importing water in tankers and bags.