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Interstate water resource risk management: towards a sustainable future for the aral basin

Final Report Summary - JAYHUN (Interstate water resource risk management: towards a sustainable future for the Aral basin)

The overall aim of the project JAYHUN was to ensure a sustainable future for the Aral basin that takes account of the rapid glacier melt that is taking place in the upper catchment and the rapid decline in reservoir storage capacity caused by siltation. These aspects have been widely neglected in past studies, and unless they are taken into account in the water planning process, they will cause further environmental degradation in the basin and significant economic disruption as water resources become scarcer. The environmental risk in the Aral Sea basin is directly linked to the issue of water shortages, especially during dry years - which are relatively frequent. The Aral Sea is now lost, and important efforts of management and planning are needed to save the remaining Tugay forests and riparian vegetation.

Moreover, the five million people living in the lower Amu Darya and Syr Darya basin are at risk because of the problem of an inadequate supply of drinking water and increasing salinity of the water resources. While the water scarcity is of human origin, the situation is aggravated by global and climate change dynamics, which are affecting the hydrological regime of the main tributaries to the Amu Darya and Syr Darya.

About 60 % of the water that potentially flows to the lower Aral Basin originates in the high mountains of Tajikistan. Existing dams like Nurek and those that are under construction such as the Rogun control and regulate the annual flow regime. The demand for winter hydropower generation in the upstream countries, where the dams are located, conflicts with the summer demand for irrigation in the downstream parts of the basin. In addition, the actual available water resources are less than those considered in the official negotiations due to siltation and reduced storage capacities, and the summer runoff generation is affected by the glacier shrinkage, which has not been taken into account up to now. Thus, poor and inadequate information on the available water resources is leading to erroneous planning decisions and a biased distribution of water resources. Hence, these issues contribute to interstate transboundary water sharing conflicts between the riparian states.

The specific objectives of the JAYHUN project have therefore been to:
- to provide a precise basis for a safer allocation of water resources under changing hydrological conditions to minimise risk of further environmental degradation;
- to establish realistic estimates of the amount of water that might be expected from the upper catchment in the next 50 years;
- to improve the regional capabilities to forecast the annual available water resources for irrigation and drinking water supply in the lower parts of the Aral basin;
- to determine the actual volumes of usable water in the large upstream reservoirs;
- to develop improved reservoir operation and water management strategies to consider future decrease of available surface water resources in the allocation of transboundary water resources;
- to determine the minimum water requirements for the basins;
- to identify a sustainable water resource management strategy for the basin that will ensure equitable allocation to all riparian needs including the environmental needs.

The project was structured into seven Work packages (WP), as follows:
- WP 1 - Organisation
- WP2 - Determination of the rate of loss of water storage in reservoirs
- WP3 - Establish reliability of water supply from mountains at a time of climate change
- WP4 - Study of existing water supply to nations, irrigation schemes and the environment
- WP5 - Development of a sustainable water resource management package
- WP6 - Evaluate the implications for the irrigation of the region and investigate socially and politically acceptable solutions
- WP7 - Development of a political dimension to the risk management.

A management strategy for the water resources of the region was developed by firstly determining the rate of glacial retreat and the implications for future water resources and the assessment of the likely impact of global changes on the annual precipitation in the region. The water use within the project area was estimated by using historic data and reference analysis.

The data were analysed in water resources models that were calibrated on existing data and then used to look at different scenarios up to 80 years into the future by combining the data gathered from the data collected and analysed within the project.

The central and most important result of the project is a risk analysis on future risk and the identification of sustainable management options for the water resources of the Aral Basin.

There are many risks to the water resources of the region but the main threats comes from climate change and a growing rural population, leading to less water and an increased demand for irrigated land within the riparian states. There are inadequate water resources to support irrigation expansion in the Amu Darya basin under present climatic conditions.

The condition of the water infrastructure and the available information systems are inadequate and do not allow effective use of the abstracted water resource, resulting in a significant proportion of the command area being not irrigated or poorly irrigated in most years. There is excess wastage of water, a considerable amount of which has very high abstraction costs.

It may not be possible completely to mitigate the adverse effects of climate change but there is considerable potential to reduce them. Examples of how water use efficiency might be improved are given below:
- Stop irrigating land with low water use efficiency.
- An enforceable management strategy needs agreeing for the allocation of the water resources under extreme shortages and needs to be effective before it happens, otherwise experience shows that downstream users always lose out.
- Use non-saline renewable groundwater below irrigation projects to supplement irrigation in dry years. Groundwater provides inter-seasonal storage and can provide a smoothing of the annual availability of the water resources. Scavenger wells can be used to tap fresh water lenses in an otherwise saline aquifer.
- Within the irrigation massifs, where drainage does not return to the river during the irrigation season, if the salinity (Electrical conductivity or EC) of the water is less than 4 dSm, it should be recycled directly into canals using low lift pumps to prevent wastage.
- Fallow fields in irrigated land should be avoided. The fallow lands attract lateral seepage from irrigated areas and thus create unwanted evapotranspirational losses from shallow groundwater, decreasing project efficiency. Large contiguous blocks of land should be irrigated.
- Increase in productivity of the irrigated land is needed by using improved agronomic techniques.

- Fields require laser grading to provide improved water application efficiency.

Constraints on implementing such strategies are the same as those that presently limit the performance of the irrigated sector, which are lack of investment and a need to modernise irrigated agriculture. Delaying investment in all sectors of water management and irrigated agriculture will only accelerate the decline in areas that can be irrigated, and thus increase its severity.

The JAYHUN project has managed to bring together a range of modern tools for water resource planning that can provide solutions to complex water resource planning in a large basin. The project's real innovation lies not in each single tool but in their combination in an integrated package. In the past, considerable resources have been spent on investigating the Aral Sea crisis but unfortunately most studies had not addressed the issue of the reliability of underlying data. In the course of the JAYHUN project, cost effective tools were implemented which were capable of efficiently acquiring data over the vast area of the basin. This approach was essential since the data collection system had largely collapsed, and considerable amounts of the existing official data were not always of good quality.

In addition to deepening the collaboration between European and Central Asian research institutions, the JAYHUN project has also been successful in providing an expandable platform for scientific and institutional exchanges allowing a wider understanding of the problems in the Amu Darya region.

The project has furthermore established authentic boundary conditions to achieve a sustainable water resources management in the Aral Sea basin. Without these conditions, this level of sustainability would most certainly not be possible.