The Growing Need to Reverse Declining Caspian Sea Levels

Caspian Sea, Azerbaijan
Caspian Sea, Azerbaijan

Published Nov 17, 2018 9:43 PM by Harry Valentine

During the mid-1970s, water levels in the inland Caspian Sea dropped to record lows before steadily rising until mid-1990s. Since 1995, water levels began to steadily decline by seven centimeters per year. Warmer summer temperatures have increased evaporation as summer winds push the humidity south across Iran toward the Arabian Sea. A population of some 80 million people would benefit from action aimed at replenishing Caspian Sea water levels and maintaining optimal peak levels.


While water levels of inland lakes and inland seas have risen and fallen over many centuries, this latest trend of warmer summers would likely extend into the long-term future. To the east of the Caspian Sea, irrigation caused water levels in the Aral Sea to drop to critical before efforts to replenish water levels began. The Aral Sea has begun to recover. Water levels in the Caspian Sea and Dead Sea have dropped for entirely different reasons. Recognizing a potentially critical situation, the King of Jordan initiated discussion about building a canal between Gulf of Aqaba and the Dead Sea.

By comparison, the Caspian Sea is far more critical to the economies of nations that surround that Sea than either the Aral or Dead Seas. If left unresolved, continued declining water levels in the Caspian Sea would likely spell economic disaster for nations such as Iran, Iraq, Southern Turkey and Syria. Winter winds carry moisture from the Caspian Sea to the watershed areas of rivers that flow through these nations and a shrinking Caspian Sea would produce steadily declining winter evaporation.

Russian Assistance

Action initiated by the Kremlin would decide the economic future of several nations located to the west and southwest of the sea. Central Russian summer rain flows into the Volga River before emptying into the Caspian Sea. The Don River flows within close proximity of both the Volga River and the Caspian Sea and supplies water to the Tsimlyansk Reservoir located west of Volgograd. Future rainfall and future Russian water requirements would determine if Russia could divert water from the Don River to the Caspian Sea.

The Donets Rivers join into the Don River to the west of the dam and water requirements along that river would determine the feasibility of diverting water to the Caspian Sea. A combination of declining summer rainfall and increasing Russian water requirements could reduce the volume of water that could be diverted toward the Caspian Sea. The option of last resort would involve the construction of an underground pipeline 700 kilometers long built across or below lowland area located between the Sea of Azov and the Caspian Sea, to carry water to the inland sea.

Pipeline Hydroelectric Power

Both an above ground water pipeline and an underground water pipeline would consume a considerable amount of energy to pump water to higher elevation from the Sea of Azov and toward the Caspian Sea. However, given that the Caspian Sea surface is 28 meters below maritime sea level, there may be scope to install hydraulic turbines where the pipeline empties into the Caspian Sea. The energy generated at the Caspian Sea pipeline exit would be used to drive water pumps located at the pipeline entrance at the shore of the Sea of Azov.

While the operation of the water pipeline would require much energy, there may be some excess hydroelectric power that may be diverted to a nearby Russian town located on the Caspian Sea. Construction of the water pipeline would likely require some underground tunneling to carry low-salinity water from the Sea of Azov to the Caspian Sea. Hydraulic turbines made of corrosion resistant steel should offer many years of service before replacement by newer turbines would be required. Filters installed at the pipeline entrance could prevent aquatic life from the Sea of Azov transferring into the Caspian Sea.

Pipeline Capacity and Operation

The volume of water the pipeline may carry would need to replenish Caspian Sea water levels and maintain traditional peak water levels. Such requirements could require an oversized pipeline that would operate for perhaps eight to 10 months per year after the inland sea reaches optimal long-term levels. During the downtime periods, maintenance crews would undertake upkeep and repairs. In the future, there would be need to develop technology that could greatly increase Caspian Sea winter evaporation that prevailing winter winds blowing from Russia could carry toward watershed areas located in mountainous areas located west of the sea.

Despite its comparatively small size, winter evaporation from the Caspian Sea is the main source of moisture that precipitates into rainfall that in turn provides nations such as Iraq, Syria along with parts of Iran and parts of Turkey with water. During a period of declining water levels in the Caspian Sea, a water pipeline connecting the Sea of Azov with the Caspian Sea would likely determine the long-term economic future of these regions. The future absence of such a water pipeline could result regional political conflict over water resources and mass migration of people toward Western Europe.

Maritime Transportation

Declining water levels in the Caspian Sea will restrict the size of vessels that could sail to/from Caspian Sea ports and potentially restrict operation of the navigation locks that provide access to the Volga River. There have been ongoing discussions about a Eurasian Canal to trade and carry commerce between the Black Sea and Caspian Sea. The route would connect across the Sea of Azov via the Don River, passing through the Tsimlyansk Reservoir and via navigation locks between the Volga River and Caspian Sea. More recent discussions have revolved around widening and deepening the canal to transit larger vessels.

However, the topography along the proposed Eurasian Canal route is unsuitable to allow for the free-flow of water from the Sea of Azov into the Caspian Sea. Russia’s growing population would likely have increasing domestic need for water from the Tsimlyansk Reservoir. A separate water pipeline or equivalent irrigation-type canal that bypasses the Tsimlyansk Reservoir would be required to carry replenishment water from the Sea of Azov to the Caspian Sea. There appears to be support from China to include the Eurasian Canal as part of their Great Silk Road initiative connecting Europe and Asia.

American Economic Sanctions

There is potential for American economic sanctions on Russia to restrict Russia’s ability to finance construction of a water pipeline between the Sea of Azov and the Caspian Sea. Sufficient water levels in the Caspian Sea would provide nations such as Kazakhstan, Turkmenistan and Azerbaydzhan with maritime transportation access to the Sea of Azov, Black Sea and into the Danube River. American sanctions would likely hinder future efforts aimed at maintaining Caspian Sea water levels and to the detriment of several emerging economies located to the south of the Black Sea.

Several nations depend on the Caspian Sea for fishing, to provide trade access and to provide critical evaporation that sustains winter rainfall in the mountains to the west of the inland sea. An initiative such as a water replenishment pipeline could help maintain traditional peak water levels throughout the year. It would allow for the installation of technology that can greatly increase winter evaporation and winter rainfall in watershed areas of rivers that sustain a population of over 80 million people living in the region between Caspian Sea, Black Sea and Persian Gulf.

Persian Gulf Salinity

The major rivers that flow into The Gulf are the Tigris, Euphrates and Karun Rivers that flow from mountainous watershed regions that receive winter rainfall from moisture blown in from the Caspian Sea. Several nations located along the western side of The Gulf desalinate seawater to provide potable water for their populations. Without a regular flow of saline-free water into The Gulf from the major rivers, ongoing desalination would gradually increase salinity and in the future, raise the energy requirement and cost of desalination for such nations as Kuwait, Bahrain, Qatar, Abu Dhabi, Dubai and Sharjah.

Warm summer weather exceeding 40 degrees Celcius results in Gulf water temperatures exceeding 30 degrees Celcius from June to October. During this period, accelerated evaporation results in elevated levels of humidity across The Emirates region and including in heavily populated areas where demand for potable water increases as salinity in The Gulf also increases. The need for potable water in The Gulf region has actually prompted discussion about towing a portion of an iceberg from the Antarctic to provide additional potable water. A possible local solution could involve maintaining peak water levels in the Caspian Sea.

A Future Micro-Climate

Future maritime transportation between the Black Sea and Caspian Sea along with river navigation along the southern portions of the Tigris and Euphrates Rivers would directly and indirectly depend on maintaining optimal peak water levels in the Caspian Sea. There will be future need to combine maintaining such water levels with using technology to greatly increase winter evaporation that winter winds may carry into mountains located west and southwest of the Caspian Sea. Possible future increased winter rainfall would require construction of canals, dams and water pipelines in Southern Turkey and northwestern Iran.

The realization of a future micro-climate that could provide water for population consumption, increased agriculture and waterway transportation would require cooperation among several nations. Some national leaders may need to put aside political disagreements and religious differences in the interest of cooperating to assure sufficient water for future generations in the region. The alternative may be a repeat of declining water levels in the Aral Sea on a much larger scale, except driven by climate instead of by irrigation. Some Middle Eastern political leaders may be horrified at the prospect of cooperation with Iran.


Caspian Sea levels have been steadily dropping for more than 20 years, with the future likelihood of further decline caused by the combination of warmer weather, increasing population along the Volga River, greater water usage by that growing population and reduced summer rainfall over the watershed area. While diverting water from the Don and Donets Rivers to the Caspian Sea might not be an option, there is the possibility of transferring water via buried pipeline from the Sea of Azov and the Caspian Sea. Such a pipeline could benefit a population of between 80 to 100 million people.



The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.