The Water-Energy-Land Nexus Project (IKI Nexus Project) supports regional and transboundary cooperation among the countries of Central Asia in the field of water resources management and the application of the water-energy-land nexus approach.
This work is also carried out under the Programme of Work of the International Water Assessment Centre (IWAC) for 2025-2027, adopted by the Meeting of the Parties to the Convention on the Protection and Use of Transboundary Watercourses and International Lakes (Water Convention) at its tenth session. As a collaborating centre of the Water Convention, IWAC supports the implementation of the Water Convention, with particular attention to the countries of Central Asia, and carries out activities under the Programme of Work mandated by the Meeting of the Parties.
Within this framework, on 1 July 2026, support was provided for the first bilateral meeting of Kazakhstan and Uzbekistan aimed at strengthening cooperation on the protection and sustainable use of the Pretashkent Transboundary Aquifer. This initiative is regarded as a starting point for the development of transboundary groundwater cooperation in Central Asia and is expected to serve as a model for the preparation of similar bilateral agreements covering other shared aquifers in the region.
The Pretashkent Transboundary Aquifer is an important regional source of mineral groundwater. It extends along the border between Kazakhstan and Uzbekistan, and the groundwater extracted in the Saryagash area is estimated to be approximately 6,000 years old. The total groundwater reserves are estimated at 143.3 km³, of which 97.6 km³ are located in Kazakhstan and 45.7 km³ in Uzbekistan.
Active exploitation of these groundwater resources began during the second half of the twentieth century. The first deep wells were drilled in 1947, while commercial extraction started in 1955. Today, the aquifer is an important source of thermal mineral water, widely used for health resort treatment, bottled water production and, in some areas, domestic drinking water supply. Among the earliest well-known mineral water brands originating from this aquifer are Saryagashskaya in Kazakhstan and Tashkentskaya in Uzbekistan.
The key information on the condition of the Pretashkent Transboundary Aquifer and the challenges associated with its sustainable development was established underthe Groundwater Resources Governance in Transboundary Aquifers (GGRETA) Project. As of 2021, groundwater extraction was carried out through 51 production wells, of which 37 are located in Kazakhstan. In 2020, groundwater abstraction reached 8,755 m³/day on the Kazakh side and 1,165 m³/day in Uzbekistan. Most of the extracted groundwater is used for municipal water supply and as therapeutic mineral water in the health resort sector.
The rapid expansion of health resorts and mineral water bottling enterprises relying on the Pretashkent Aquifer is leading to groundwater depletion and increasing risks to its long-term sustainability. In particular, groundwater abstraction has resulted in the formation of regional cones of depression ranging from 109 to 140 metres deep in areas where spa facilities are concentrated. In the future, most production wells are expected to require conversion to pumped extraction. Moreover, the groundwater currently being exploited is essentially non-renewable, meaning that the resource is not replenished on a human timescale.
The long-term preservation of the Pretashkent Transboundary Aquifer can only be achieved through coordinated action by both Kazakhstan and Uzbekistan. In each country, groundwater management is shared between at least two government authorities. In Kazakhstan, these include the Ministry of Water Resources and Irrigation and the Geology Committee of the Ministry of Industry and Construction. In Uzbekistan, responsibility lies with the Ministry of Mining Industry and Geology and the Ministry of Water Resources. Once groundwater is extracted from the subsurface, its protection and use fall under water legislation and are therefore regulated by the national water authorities.
At the same time, there is currently no formal legal framework governing cooperation between Kazakhstan and Uzbekistan on the protection of this shared groundwater resource, despite its active use by both countries. Prior to 1991, the allocation and use of groundwater resources were managed by the water authorities of the Soviet Union. Since then, oversight of groundwater use has significantly declined.
It should be noted that on 15 November 2025, the Agreement between the Government of the Republic of Kazakhstan and the Government of the Republic of Uzbekistan on the Joint Management and Rational Use of Transboundary Water Bodies was signed. The Agreement has completed all domestic approval procedures in both countries: it was approved in Uzbekistan on 6 March 2026 and ratified by Kazakhstan on 9 July 2026. Its implementation will include the establishment of an Intergovernmental Kazakhstan-Uzbekistan Commission to strengthen coordination on water allocation and use and to reduce the risk of disputes. However, issues related to cooperation on transboundary groundwater remain outside the scope of the 2025 Agreement and therefore continue to require dedicated arrangements.
The meeting held on 1 July 2026 was organized to discuss approaches for preparing a draft Memorandum of Understanding between the Republic of Kazakhstan and the Republic of Uzbekistan on cooperation in the protection and sustainable use of the Pretashkent Transboundary Aquifer. During the meeting, participants reviewed international experience in transboundary groundwater cooperation, discussed the possible structure of the future Memorandum, and exchanged views on joint monitoring, data sharing, the use of a mathematical groundwater model, and potential institutional arrangements for cooperation.
At the conclusion of the meeting, participants reaffirmed their commitment to further developing bilateral cooperation on the protection and sustainable use of the Pretashkent Transboundary Aquifer. The parties agreed to continue preparing the draft Memorandum through a step-by-step consultative process involving the exchange of written proposals, expert consultations, and the preparation of a mutually agreed draft document.
Participants proposed the following conceptual approaches for the Memorandum on the Pretashkent Transboundary Aquifer:
- to limit its scope to a single transboundary groundwater body;
- to focus on practical aspects of bilateral cooperation;
- to use the existing mathematical groundwater model as one of the principal tools for information exchange, analysis, and joint management;
- to consider appropriate institutional mechanisms for its implementation.
