Reflecting on NEXUS Gains’ outcomes in Central Asia: Upstream responses to the Aral Sea disaster

The Aral Sea was once the world’s fourth largest lake, but since the 1960s it has become one of the world’s worst environmental disasters – an infamous case of ecological collapse. Diverting water for irrigation, originally to support cotton farming in what was then the Soviet Union, dried out the lake to the point where only small remnants remain. Today, ninety percent of its vast area is dry. Dust storms carry salt and dangerous chemicals from the desiccated seabed across the plains, causing severe harm to ecosystems, agriculture, and human health. One of Asia’s most magnificent freshwater resources has been lost to policies that prioritized short-term gains without consideration of the unforeseen, but catastrophic, consequences.

The CGIAR Initiative on NEXUS Gains has worked for three years at the nexus of water, energy, food, and ecosystems (WEFE) in Central Asia. While the drying of the Aral Sea is the region’s most visible and dramatic environmental disaster, it is part of a broader pattern of environmental degradation that includes the salinization of nearly half of all irrigated land, soil erosion, water scarcity, and biodiversity loss. Ninety percent of freshwater withdrawals in Central Asia are consumed by agriculture, now mostly for cereals and in particular wheat, but also cotton production. Half the population lives in areas of high water stress, and renewable water resources have declined sharply since the 1960s. All of this has been exacerbated by a 1.5°C temperature rise and the melting of glaciers.

NEXUS Gains collaborated with Central Asian governments and stakeholders to counter further environmental degradation through the development and testing of integrated WEFE nexus solutions. The needs of the countries vary: while Kyrgyzstan and Tajikistan use the headwaters of Central Asia’s largest rivers to generate most of their electricity, downstream Kazakhstan, Turkmenistan, and Uzbekistan use a large proportion of their energy to pump water to crops, at a cost of 10–20 million tons of CO₂ emissions a year. Agricultural productivity is limited by fluctuating water supplies and salinization. Nevertheless, by taking action now, these countries foresee a greener future beyond the devastation of the Aral Sea.

Considering environmental degradation

Much of NEXUS Gains’ work in Central Asia was driven by the needs of water users to better understand and anticipate the environmental consequences of their water management practices. In response, the International Water Management Institute (IWMI) in partnership with the University of Manchester used the Pywr modeling tool to develop a multi-scenario simulation of the Amudarya Basin – home to one of the two great rivers that once filled the Aral Sea. Pywr is a model for solving resource allocation problems and assessing the impacts of planned interventions, such as hydropower and irrigation projects, with real-world data.

However, limited monitoring infrastructure and fragmented data across different organizations, countries, and sectors posed significant challenges. Stakeholders needed to see and understand what the model could do before committing to support IWMI in validating and calibrating it across the basin. Acting on stakeholder recommendations, IWMI started by applying the Pywr model to the smaller Chirchik Basin, where high-quality data were available through collaboration with the Scientific-Information Center of the Interstate Commission for Water Coordination (SIC‑ICWC). Now fully operational in the Chirchik Basin, the tool is being used to assess water uses and evaluate levels of efficiency, water storage, and environmental flows necessary to prevent degradation of aquatic ecosystems. Amid great interest from decision-makers, IWMI handed over the model to the SIC‑ICWC for scaling up to wider use.

Considering alternative land and water management

The Aral Sea disaster resulted from management decisions made a great distance away, but with devastating impacts. By the same token, decisions made today can contribute to reversing the disaster and adapting to new challenges exacerbated by climate change. Tools to help make decisions, anywhere and at any scale, are therefore essential. One of these is the International Center for Agricultural Research in the Dry Areas (ICARDA)’s Decision Support Tool: an easy-to-use tool aimed at integrating WEFE priorities for land and water management. The tool empowers stakeholders with the information required to navigate complex trade-offs and synergies between WEFE sectors. Piloted with ministries in Uzbekistan, the tool integrates stakeholder inputs through targeted questions to weigh sector priorities. This approach helps decision-makers identify optimal practices that address diverse priorities among WEFE sectors, fostering inclusive and sustainable solutions for the Aral Sea Basin.

Water storage is another vital consideration, and here too, promising alternatives are often overlooked, since water is effectively sourced and shared in many ways, including from surface water, groundwater, and soil moisture. To broaden storage options and reduce dependence on withdrawals directly from rivers, IWMI conducted a comprehensive mapping of water storage in the Fergana Valley, a region of transboundary catchments split between Uzbekistan, Kyrgyzstan, and Tajikistan. Using remote sensing technology, researchers mapped permanent and seasonal water resources, integrating 25 small tributaries in an online dashboard. This tool helps decision-makers evaluate potential storage options across the landscape, enhancing local environments and allowing more river water to flow downstream toward the Aral Sea.

In areas surrounding the Aral Sea, meanwhile, Uzbekistan has striven to promote efficient irrigation technologies like drip irrigation, which could save scarce water resources and reduce energy needs. The International Food Policy Research Institute (IFPRI) has supported this effort with in-depth studies into the barriers to adoption of these technologies and the low effectiveness of subsidies designed to enhance farmer uptake. A series of studies used gender-disaggregated surveys, behavioral games, analysis of social media groups, and in-person focus groups to advise on how subsidies for drip irrigation could better reach women and small-scale farmers.

As part of the intra-household survey, IFPRI also implemented the Women’s Empowerment in Agriculture Index (as well as the Women’s Empowerment in Energy Score) and found that the level of empowerment among women from small-farm households was very low. The main areas of disempowerment are group membership, work balance, and access to and decisions on credit. Given the important role that women play in agriculture, increasing their agency by developing credit products directed at women farmers, improving their access to time-saving technologies, and strengthening existing support groups can support several human development goals, in addition to Sustainable Development Goal 5 on gender equality.

Considering governance and capacity

NEXUS Gains has played a key role in developing the capacity of public WEFE sector institutions. A scoping study designed to assess the needs of emerging women, men, and youth leaders helped shape the creation of the 2023 International Summer School on Sustainability Assessment of the WEFE Nexus for Irrigated Agriculture. Held in Tashkent, this major event trained participants in the use of sustainability assessment methods that integrate ecosystem services, resource use efficiency, soil quality maintenance, human health, economic viability, gender equality, and social inclusion. The training materials from the Summer School are available online in the collection WEFE Approaches for Central Asia. Additionally, a complete set of NEXUS Gains-developed course materials is being used by the Tashkent Institute of Irrigation and Agricultural Mechanization Engineers to train professionals in these sectors. Universities in Kyrgyzstan, Tajikistan, and Uzbekistan are forming ‘Nexus Corners’: spaces where students and young researchers can go to get information about nexus approaches, including nexus-related tools and materials.

Groundwater governance is another neglected area for which substantial capacity building is needed in Central Asia. Groundwater use is notoriously difficult to govern, and too often it is wrongly assumed to be disconnected from the health of rivers and lakes. In reality, surface water and groundwater are strongly interlinked, but sharing data to establish these linkages is especially challenging because of the transboundary nature of surface flows and aquifers, as shown by a recent article as part of the NEXUS Gains study of groundwater governance. NEXUS Gains, working particularly through its groundwater governance toolkit, has expanded the understanding of this important resource base. In one study in a groundwater-dependent district of Uzbekistan, IWMI used data from 63 observation wells to track year-on-year changes in groundwater levels. This research highlighted significant fluctuations, and demonstrated the need for better groundwater management particularly for basin-level water management authorities that traditionally restrict their scope to managing surface water.

From groundwater monitoring to farmers’ adoption of technologies, river modeling, land and water management, and water storage, NEXUS Gains researchers have addressed many of the complex challenges facing Central Asia’s people and ecosystems. Above all, the WEFE nexus emphasizes the interconnectedness of countries and communities. NEXUS Gains’ work reflects this broader perspective, drawing critical lessons from the cautionary tale of the Aral Sea and underlining the importance of integrated, sustainable resource management to preserve the region’s fragile environments.

This work was carried out under the CGIAR Initiative on NEXUS Gains, which is grateful for the support of CGIAR Trust Fund contributors: www.cgiar.org/funders

Header image: Farmer managing a kitchen garden in rural Tajikistan. Photo by Madeline Dahm/IWMI.