Paradoxically, the Caspian Sea is becoming one of Eurasia’s most important transport hubs at a time when its falling water level is creating growing constraints on navigation. As sanctions disrupt traditional trade routes through Russia, countries are investing in the Middle Corridor as an alternative link between Asia and Europe. Yet the continuing decline in sea level is limiting shipping capacity and increasing the risks and costs associated with long-term infrastructure projects.
The first Caspian Environmental Summit, held in Turkmenistan on October 9, 2026, drew attention to the scale of these changes. Between 2000 and 2025, the Caspian Sea shrank by more than 16,000 square kilometers, while in some areas the shoreline receded by tens of kilometers.
How the Caspian’s Falling Water Level Affects Freight
The Middle Corridor, linking China, Central Asia, the Caspian Sea, the South Caucasus, Turkey, and Europe, is seen as a promising route for diversifying international trade. Its development can reduce shippers’ dependence on individual transport routes and improve economic ties among countries in the region.
According to the World Bank’s latest study, more than $25 billion in investment in the corridor’s core physical infrastructure will be needed through 2040. An additional $30 billion could be required for enabling infrastructure and services.
The bank estimates that if infrastructure investment is combined with institutional reforms, freight volumes along the corridor could quadruple and travel times could fall by about two-thirds by 2040.
A study by the Organisation for Economic Co-operation and Development (OECD) notes that insufficient depths are already preventing vessels from being fully loaded, reducing transport efficiency and increasing costs.
Large-scale dredging was carried out at the Port of Kuryk in 2024. Over four months, around one million cubic meters of material were removed, and the depth of the operational port area was increased to 7–8 meters, according to the port operator. This made it possible to load vessels to full capacity. Meanwhile, major dredging work is underway at Aktau, where 1.3 million cubic meters of material are to be removed to increase water depths to 6–7 meters. The work is expected to be completed by the end of 2026.
Dredging, however, can only maintain the operation of individual port facilities, while further declines in the sea level may require repeated work or the reconstruction of berths.
Where draft restrictions prevent full loading, transport companies may need to make more voyages to carry the same volume of cargo, increasing spending on fuel, crews, maintenance, and port operations.
Constraints on the maritime section can also lead to delays for railcars and containers and disrupt transshipment schedules. These disruptions reduce the predictability of deliveries along the entire route.
Similar problems are emerging on the western coast of the Caspian. Falling water levels are reducing vessel cargo capacity at Azerbaijani ports and oil terminals and requiring additional dredging.
Infrastructure for Decades Ahead
According to the OECD study, which cites World Bank climate projections, under a high-emissions scenario in which the Caspian water level falls by about five meters between 2025 and 2100, existing berths could become unsuitable for further modification. In that case, entirely new berths could be required, or individual port facilities might even have to be relocated.
For Kazakhstan, this raises a practical question: to what extent are the expansion projects at the Aktau and Kuryk ports designed for different scenarios of sea-level change? Without such an assessment, there is a risk that today’s investments in additional capacity will later require further spending on adaptation.
Alternative engineering and operational solutions also need to be considered. In addition to dredging, these could include berth modernization, the use of vessels with shallower drafts, fleet renewal, and changes in the organization of transport operations.
From an Environmental Summit to Economic Coordination
The summit highlighted the possibility of moving toward more coordinated action by the five littoral states.
Kazakhstan proposed a shared digital platform for monitoring the condition of the Caspian and supported Azerbaijan’s initiative to establish an intergovernmental commission on the decline of the Caspian Sea water level. It also proposed developing an interstate program for conserving the sea’s water resources, an initiative endorsed by the other littoral states.
Joint hydrological research and data sharing could make infrastructure planning more predictable and help identify priority areas for dredging. These measures could reduce risks associated with investment decisions.
Russia and Kazakhstan have a particularly important role in this work, given that the Volga provides most of the Caspian’s river inflow and the northern basin is by far its shallowest part. Sustainable management of Caspian risks, however, also requires the participation of the other littoral states, including Iran.
The success of Caspian initiatives will depend to a large extent on whether all littoral states can share data regularly and use comparable hydrological forecasts for joint planning of specific projects.
What Kazakhstan Needs
For Kazakhstan, further development of the Middle Corridor requires closer integration of transport and climate policy.
A first practical step could be to include several scenarios for changes in the Caspian Sea level in the feasibility studies for major port projects.
A second step would be to develop a long-term adaptation program for Aktau and Kuryk that takes into account the condition of access channels, depths at berths, vessel characteristics, and projected freight flows.
A third step would be to use Caspian cooperation mechanisms to coordinate hydrological forecasts and exchange technical information between ports on the eastern and western coasts.
Finally, a more transparent assessment of the economic consequences of falling water levels is needed. Publishing comparable data on water depths, vessel-loading restrictions, adaptation costs, and the effect of these factors on tariffs would allow investors and shippers to assess the route’s long-term prospects more accurately.
In this context, the Middle Corridor’s long-term competitiveness will depend to a large extent on the ability of its participants to assess climate risks in advance and coordinate the development of port infrastructure. They will also need to maintain predictable transport costs.