Is the proposed Red Sea-Dead Sea canal worth the cost?August 12, 2008
The decline in the level of the Dead Sea has led to concern about the long-term sustainability of the lake. This decline, which was caused by the diversion of fresh water from the headwaters of the lake, is estimated to range from 0.8-1 meter per year. In order to reverse this trend, it is being proposed that Red Sea water be pumped to replace the fresh water that previously flowed into the lake. Recently, an agreement was signed to study the economic feasibility of the project, which is currently expected to cost 3.3 billion dollars.
There is a clear political will to go through with this project. However, it is useful to look at the environmental and financial benefits that are expected from this project and weigh them against the enormous costs, which will be both environmental and financial.
The Dead Sea
The Dead Sea is a closed water body which lies at the lowest point of the Jordan Valley Rift. It consists of two distinct basins. The Northern basin is the largest, containing 131 cubic kilometers of water and occupying about 660 square kilometers out of the total of about 950 square kilometers of the historic Dead Sea. The shallow southern basin is now completely exposed, with water pumped from the northern basin to fill salt pans. These salt pans are used to extract potash and other Dead Sea chemicals.
Closed water bodies in arid regions typically fluctuate widely over time. These fluctuations reflect changes in climatic conditions that lead to changes in precipitation and evaporation rates. The Dead Sea is no exception to this. Studies indicate that during the Holocene, the water level fluctuated from a high of 280 meters below sea level 6700 years ago to a low of 396 meters below sea level 3000 years ago. The current water level is about 415 meters below sea level which is a historic low.
The famous mosaic map of the Jordan river basin in Madaba was produced 560 AD, and shows an absence of the southern basin. This indicates that the water level at the time was below 405 meters below sea level. More recently, measurements in 1865 indicate levels of 394 meters below sea level and in 1929 levels were recorded at 389 meters below sea level (Abed, A., 1985. Geology of the Dead Sea. Dar Al Arqam publishing, Amman (in Arabic)).
Thus, it is clear that the Dead Sea is dynamic in behavior, responding to changes in climatic conditions which force fluctuations in its level. The recent drop is the result of Human intervention. Historic flows into the Dead Sea were estimated to reach 1670 million cubic meters per year, whereas current inflow is estimated to be only about 400 million cubic meters per year. Given constant rates of evaporation, the drop in water level is a predictable outcome.
Dangers associated with the drop in Dead Sea water levels
From what has been discussed, fluctuations in the level of the Dead Sea are natural and part of the nature of the water body. Therefore, consideration of real and perceived dangers associated with this drop should be balanced with the dangers that might occur in case the Red-Dead Sea canal alternative is adopted.
1-Will the Dead Sea disappear?This question has been answered through a number of modeling projects which attempted to determine what might happen if conditions persist in their present form or become worse.The modeling is based on assumptions of input rates (runoff from the Jordan River and other tributaries) and direct precipitation over the water body.Assumptions concerning an evaporation rate, which is the only way for water to leave the Dead Sea, are based on studies related to how the change in salinity will affect evaporation.Evaporation decreases as salinity increases.Moreover, the drop in water level means that the surface area exposed to evaporation will steadily fall.This will also lead to drops in evaporation.
The results of models run based on these factors suggest that the Dead Sea level will reach 460 meters below sea level in 2088, and will stabilize at 520 meters below sea level in the next 400 years, when a new equilibrium will be reached. In the event that inflow falls to 300 million cubic meters per year, then the water level will be expected to fall to 560 meters below sea level in the next 400 years, when equilibrium will be attained.
Upon examining the bathymetric map of the Dead Sea, this drop will lead to the recession of between 500 and 1200 meters at the northeastern end of the water body, and at the southern end this will lead to a recession of 7 kilometers. It is noteworthy that the western shore will be much more affected by the recession of the shores than the eastern shore.
So, the Dead Sea will not disappear, but a new equilibrium will be attained in 400 years at levels ranging from 520 to 560 meters below sea level. There is no doubt that this drop will have adverse effects on the chemical industries extracting salts from the Dead Sea as well as on the tourism infrastructure built on the current situation in the area.
2-Ground water in adjacent aquifers. The major aquifers in central Jordan lie adjacent to the Dead Sea rift. Some of these aquifers are higher than the Dead Sea level and discharge as springs that eventually flow into the Dead Sea. Other aquifers lie below the Dead Sea level and discharge directly as underwater springs into the sea, and are considered to be part of the hydrological budget of the water body. Because there is a pressure balance at the fresh water-salt water interface, drops in the sea level lead to the moving of the interface towards the sea. This leads to increase in the flow of water from the aquifers into the sea, and the lowering of the water levels in the aquifers.
Typically, the fresh water salt water interface is studied for totally different reasons. In most cases, the disruption of the dynamics of the system is due to overpumping of waters in aquifers adjacent to salt water seas. Such overpumping leads to the intrusion of sea water into the aquifers, leading to deterioration of the water quality within them. In the case of the Dead Sea, it is estimated that the drop in water level leads to a losses of about 370 million cubic meters per year. In other words, this volume of water can be extracted from the aquifers without any negative impacts on the water quality within them. In my view, it seems that this is a valuable opportunity which should be taken advantage of.
3-Sinkholes.The development of massive sinkholes in the Ghor Haditheh area in the southern Dead Sea area has led to inquiries as to the reason behind their formation.Some researchers have linked the formation of the sinkholes with the drop in the Dead Sea level.
The sediments in the area where sinkholes are forming consist of a mixture of clay and evaporites known as the Lisan formation. Flow of fresh water through these sediments leads to the dissolution of the evaporites and the formation of cavities, which eventually appear as sinkholes.
Because the salt-water fresh water interface is migrating towards the direction of the sea, many researchers believe that that this migration is leading to the evaporite dissolution and the development of the sinkholes.Other explanations for this phenomenon include the possibility that crop irrigation in the area is leading to the movement of fresh water into the sediments and the formation of the cavities.
If the problem is a result of the migration of the salt water fresh water interface, then increased extraction of fresh water from the aquifers in the area, as explained above, should alleviate this problem by stopping to movement of the interface. On the other hand, if the cause is related to agricultural practices in the area, then the problem is not related to the drop in the Dead Sea level.
Why the Red Sea-Dead Sea canal?
Reasons given to justify this problem can be enumerated as follows:
1-“Saving” the Dead Sea
2- Protecting the ground water in the adjacent aquifers.
3- Stopping the development of sinkholes.
4- Generating electricity.
Given that the first three points have already been discussed previously, the final two are herein analyzed.
A- Generation of electricity.The idea of a Mediterranean-Dead Sea canal has long been discussed.Theodor Hertzl proposed the idea in 1902 as a way to utilize the elevation difference between the Mediterranean Sea and the Dead Sea (about 400 meters) for hydroelectric generation.
It is estimated that the flow of 1600 million cubic meters per year down this elevation difference is capable of generating 860 million kilowatt hours per year. This is equivalent to a generating capacity of 100 megawatts. Given that this is a relatively modest amount of electricity compared to the cost of implementing it, it has been proposed to use the energy for desalination.
B- Official statements on the project suggest that it will be possible to desalinate 850 million cubic meters per year from the project.Since the amount of energy to be generated from the project is estimated to be about 860 million kilowatt hours per year, the implication is that it will take about 1 kilowatt hour to desalinate one cubic meter of fresh water from the Red Sea.
Available sources on energy needs for the desalination of sea water using currently adopted technologies (reverse osmosis) suggest that the minimum requirement for the desalination is 5 to 7 kilowatt hours per cubic meter of water. It is obvious that additional sources of energy will be needed to desalinate the volume of water envisioned by the project proponents.
Potential risks of implementation of the project
In addition to the high cost of the project, a number of environmental issues need to be considered before moving forward with this project. A number are mentioned here.
1- Salination of the Dead Sea. This might seem ironic, since the Dead Sea is already highly saline, with salt contents reaching over 30% of the volume of the water. However, it is important to note that much of the value of the Dead Sea is derived from its chemistry and its beauty.
Adding sea water and reject water from the desalination process will lead to sharp increases in the salt content of the Dead Sea water. This is because as saline water is added at a rate proportional to the evaporation levels of the sea, the water added will evaporate, but the salts within it will not. This will lead to further dissolved salt buildup in the water body.
When salinity reaches higher levels, massive deposition of halite and gypsum are to be expected. The deposition of salt as massive mushrooms in the southern basin already causes hindrance for potash production and has clearly led to the deterioration of the aesthetic value of the area. Similar problems might arise in the northern basin as salinity rises and the deposition of these salts becomes a chemical necessity.
2- Pollution of aquifers in Wadi Araba. The alluvial deposits on the edges of the rift valley contain significant amounts of fresh water being used by the inhabitants of the area as well as the Arab Potash Company. The conveyance canal containing sea water will probably traverse some of these aquifers. The possibility of leakage from the canal or pipeline will present a continued threat towards the waters within these aquifers, especially given that the area is seismically active.
3- Cultural heritage. The canal/pipeline system will go through areas of high cultural significance. Prominent among these is the Faynan area, which is a world famous and significant copper mining site, believed to be the oldest copper mining and smelting site in the world. It is hoped that the implementation of the canal project will take into consideration the significance of this site.
1- The fluctuation of the level of the Dead Sea can not be considered an environmental disaster, since this is a natural process which has gone on throughout the Holocene. The idea that the Dead Sea will dry up is not true.
2- The damage from the drop of the Dead Sea level can be quantified, as it is tied to the chemical and tourism industries in the area.
3- The drop in the water level provides opportunities to increase extraction of fresh water from adjacent aquifers with no dire environmental consequences. Moreover, expanded extraction of ground water might lead to the reduction of sinkhole development in the southern Dead Sea area.
4- The amount of energy expected from the canal project is modest in proportion to the high cost of the canal.
5- More energy capacity needs to be installed in order to reach the target level of desalinating 850 million cubic meters of water per year.
6- A number of environmental issues related to the implementation of the project need to be studied carefully before moving forward with this project.
Therefore, a critical analysis of the benefits and costs of this project needs to be conducted before moving forward with it.