General summary for the countries of the Former Soviet Union

The Aral Sea basin

The Aral Sea basin, located in Central Asia, has undergone many changes in the recent past. The Aral Sea, the world's fourth largest lake before 1960, has been progressively drying up. With the end of the Soviet era, the international community has become aware of this problem and focused on what is considered one of the major anthropogenic environmental degradations in the world. The purpose of this section is to present the Aral Sea basin, the causes of the drying up of the lake, the present trends and the solutions being studied by the governments of the countries of the region.

Water resources of the Aral Sea basin

The Aral Sea, located in a depression in the Turan plain, is fed by two major rivers: the Amu Darya in the south, and the Syr Darya in the north, which rise in the southwestern Pamir and Tien Shan mountain ranges respectively. The combined hydrologic basin of these two rivers has a total area of about 1.9 million km² and extends over six countries (Table 9). In Kazakhstan, all the flow of the Turgay, Sarysu, Chu and Talas rivers is lost in the desert or is directed to natural depressions. These rivers can be considered as not being part of the Aral Sea basin.

The assessment of natural flow in the basin is hampered by the large amounts of water withdrawn from the rivers since the 1950s. By reconstructing long-term time series, the average annual RSWR in the Aral Sea basin are estimated at 115.6 km³, of which 78.46 km³ in the Amu Darya basin and 37.14 km³ in the Syr Darya basin (Table 9). For a 20-year return period, the values are 46.9 km³ for the Amu Darya and 21.4 km³ for the Syr Darya.

Before 1960, the level of the Aral Sea was more or less stable. Its surface area was about 66 000 km² and its volume about 1 060 km³. The combined average discharge of the Amu Darya and Syr Darya rivers to the sea was about 47-50 km³/year, to which could be added 5-6 km³/year of groundwater inflow and 5.5-6.5 km³/year of precipitation over the sea. This total volume of 57.5-62.5 km³/year compensated the evaporation over the lake, estimated at about 60 km³/year. The Aral Sea level was then fluctuating at around 50-53 m above sea level. The difference between the IRSWR of the Aral Sea basin, estimated at 115.6 km³/year, and the necessary discharge to the sea for a stable water balance, estimated at 47-50 km³/year, was available for use in the basin, i.e., about 65.6-68.6 km³/year. The average mineral content of the Aral Sea's water was estimated at 10 g/litre in 1960. Fish capture was about 40 000 t/year, and many fish-processing industries were established on the shores of the Aral Sea. Together with fishing, these industries provided employment to much of the local population.

Irrigation development in the basin and the drying up of the Aral Sea

In the 1960s, the Soviet policy assigned Central Asia the role of raw material supplier, notably cotton. Irrigation was necessary due to the arid climate prevailing over the lower reaches of the Amu and Syr Darya basins. The development of irrigation in the Soviet part of the Aral Sea basin was spectacular: from about 4.5 million ha in 1960, it rose to almost 7 million ha in 1980 (Figure 1). The population increased from 14 million inhabitants in 1960 to about 27 million inhabitants in 1980. The total water withdrawal increased from 64.7 km³ in 1960 to 120 km³ in 1980, of which more than 90% for agricultural purposes (Figure 1). It resulted in the disruption of the prevailing water balance in the basin.

The consequences of this huge irrigation development are numerous:

- Many tributaries have been exploited to such an extent that they no longer contribute directly to the flow of the Amu Darya and Syr Darya rivers. They are: the Zeravshan and Kashkadarya in the Amu Darya basin, and the Arys and Akhangaran in the Syr Darya basin.

- The intensification of irrigated agriculture has led to major waterlogging and salinization. In 1995 the irrigated area was almost 8 million ha, compared with 4.5 million ha in 1960 (Figures 17 and 18). The main causes of this soil deterioration are: the low irrigation efficiencies, due particularly to the small percentage of lined canals (28% on average in the basin for the inter-farm network and 20% for the on-farm network); and the absence of a drainage network, or its poor state due to the lack of maintenance particularly in the most recent years. In 1994, about 40% of the irrigated land in the basin was saline. Agriculture in the Aral Sea basin has been practised with a high level of inputs, particularly fertilizers and pesticides, and this has resulted in the deterioration of surface water and groundwater quality. The salt content of groundwater in the lower reaches of the river basins varies between 1 and 30 g/litre.

- The traditional ecosystem of the two deltas of the Amu Darya and Syr Darya has perished. The marshes and wetland which covered some 550 000 ha and were a reservoir of biodiversity until the 1960s have almost disappeared (only 20 000 ha were left in 1990) giving way to sand deserts. More than 50 lakes, covering 60 000 ha in the deltas, have dried up.

- The Aral Sea is drying up. Its level has dropped by 17 m, its surface area has fallen by a half and its volume by three-quarters (Figure 2). At present, the sea consists of three sections: the Small Sea or Northern Sea on the territory of Kazakhstan; the Central Sea; and the Western Sea, which is the deepest one, mostly located on the territory of Uzbekistan. The mineral content of the water has increased fourfold to 40 g/litre, preventing the survival of most of the fish and wild life in the Aral Sea. The current fish capture is negligible, leaving most of the people unemployed. All commercial fishing ceased in 1982. Moreover, the former seashore villages and towns are 70 km away from the present shoreline. The exposed seabed now consists of vast salt tracts, whose sand and dust, polluted with pesticides, are carried by the wind to neighbouring areas and up to a distance of 250 km. The eolian transfer of dust and sand from the exposed seabed has been estimated at 15-75 million t/year.

- With the reduction of the size of the Aral Sea, its climate modifying function has been lost. The climate around the sea has changed, becoming more continental with shorter, hotter, rainless summers and longer, colder, snowless winters. The growing season has been reduced to an average of 170 days per year. Desert storms are frequent, occurring on more than 90 days a year.

- Communities face appalling health conditions. In Karakalpakstan, drinking water supply is too saline and polluted. The high contents of metals such as strontium, zinc and manganese cause diseases and prevent iron absorption, causing anaemia. In the last 15 years, kidney and liver diseases, especially cancer, have increased at least 30-fold, arthritic diseases 60-fold and chronic bronchitis 30-fold. The infant mortality rate is one of the highest in the world.

Measures adopted to mitigate the environmental problems

Aware of the above problems, in the 1980s the government of the Soviet Union decided to develop a Water Resources Master Plan for the Syr Darya and Amu Darya river basins. The principle of a strict limitation of water withdrawal per hectare was adopted in 1982 and it was decided to share the available water resources among the riparian republics. Decisions were taken by the Ministry of Water Management of the Soviet Union in July 1984 for the Syr Darya waters and in March 1987 for the Amu Darya waters. Two Basin Water Organizations (BWO) were established to operate and maintain the main hydraulic infrastructures and to monitor water use.

After the end of the Soviet period, the newly independent states decided to prepare a Regional Water Resources Management Strategy, but to respect the existing principles until the adoption of a new agreement on water resources sharing. At the initiative of the five republics, an Interstate Commission for Water Coordination (ICWC) was established. The ICWC supervises the two BWOs and a Scientific Information Centre, and is in charge of regulating water distribution in the basin and of consolidating the country positions for the adoption of a regional water strategy. The preparation of this water strategy, as well as regional studies and pilot projects for a new approach in water management, have received attention and funding from several international organizations and bilateral cooperation agencies. The International Fund for the Aral Sea (IFAS) and the Interstate Council for the Aral Sea Problem (ICAS) have been established in order to subordinate the initiatives and the financial resources to a regional approach.

Water supply management

The first solutions envisaged to face the problems listed above were based on water supply management. During the Soviet period, the possibilities of water diversion from the Ob River to the Amu Darya River through a 2 200 km-long canal or from the Volga River to the Aral Sea were studied. These options were abandoned with the ending of the Soviet Union. Currently, a proposal to transfer water from the Caspian Sea to the Aral Sea is being studied.

Greater use of agricultural drainage water and wastewater, as well as the introduction of more salt-tolerant crops, have also been envisaged and in part implemented. In 1993, agricultural drainage water was estimated at about 40 km³/year and the re-use of industrial and domestic wastewater was about 3 km³/year. About 6 km³/year of agricultural drainage waters or wastewater are directly re-used for irrigation. Some 37 km³/year return to natural depressions or rivers where they are mixed with freshwater and can be re-used for irrigation or other purposes.

Dam construction and canal regulation have also been undertaken to make the water supply meet the water demand in a more timely fashion.

Although these options have enabled further irrigation development, the improvements induced have not been sustainable.

Water demand management

The governments of the five Central Asian republics have thus decided to focus on demand management, which is now a key element of the national and regional water strategies. The countries have started implementing programmes which all aim to reduce the water withdrawal per hectare, but which have the primary objective of satisfying crop water requirements.

From a technical point of view, all the measures aim to increase the global irrigation efficiency: through canal rehabilitation and/or lining, which leads to a reduction of the losses; and through canal regulation for better irrigation scheduling. However, in view of the very limited funds available, these measures will be implemented gradually, relying mostly on international assistance and funding.

From an economic point of view, several countries have introduced water fees and fines for the use of water in excess of the allocation per farm. Moreover, with the move towards a market-oriented economy, farmers' responsibility has increased. For example, the decision on the crops to be grown on irrigation schemes, which has direct consequences on the water requirements, is the farmers' responsibility. In Kazakhstan, rice, a large water consuming crop, has been replaced by other cereals. In Turkmenistan and Uzbekistan, the area grown with cotton, also a large water consuming crop, has decreased while the area grown with grain has increased substantially. Although these measures may lead to a reduction of the water withdrawal, they make planning and monitoring water distribution more difficult.

Future prospects

Much progress has already been made since 1990. The total water withdrawal in the basin has now stabilized at about 110-120 km³/year (Figure 1). However, further improvement is needed to meet the increasing demand from new water users. The living standards of the population near the sea are also a major concern, with most socio-economic indicators (life expectancy, health, drinking water supply, etc.) being dramatically negative. The responsible authorities are expected to take the necessary measures.

It has been estimated that at least 73 km³/year of water would have to be discharged to the Aral Sea for a period of at least 20 years in order to recover the 1960 level of 53 m above sea level. The governments of the riparian countries do not consider this a realistic objective.

Other more feasible options for the future of the Aral Sea have been envisaged by different parties:

- The stabilization of the Aral Sea at its 1990 level (38 m above sea level) would require a total inflow of about 35 km³/year, including the demand for the delta area. However, this would not end the environmental degradation and desertification in the exposed seabed.

- The restoration of the Small Sea, or Northern Sea, to the level of 38-40 m above sea level would require an inflow of at least 6-8 km³ in that part of the Aral Sea for the next five years.

- The restoration of wetlands in the Amu Darya delta and the conservation of the Western Sea would require an inflow of 11-25 km³/year, with at least 5-11 km³ of freshwater. Since 1989, a project has been implemented in Uzbekistan which aims to bring more water to the delta through the collector-drainage network. This water, combined with freshwater, is used to replenish shallow lakes. It has allowed the re-development of flora and wildlife in the abandoned areas and stopped the eolian erosion of the former exposed seabed. Another result of this project has been a higher fish capture, estimated at 5 000 t/year in 1993, compared with 2 000 t/year in 1988.

Because the water resources of the basin are more or less stable, or even slightly decreasing due to the climatic change induced by the Aral Sea drying up, all extra water flowing to the Aral Sea should be saved from upstream existing uses. Major efforts should be made to: reduce losses in the rivers and canals, notably through lining and automatization of the distribution; stop irrigation expansion; to generalize micro-irrigation and other water saving techniques on existing irrigated areas; redirect drainage water and other spilled reservoir and canal water directly to the sea; return the non-consumed fraction of the water diverted into irrigation schemes to the Aral Sea. According to the World Bank, the introduction of a water market could help save more water.

Water quality problems increase from upstream to downstream due to the increasing salinity and pesticide content of agricultural return flow and the poor state of wastewater treatment plants in the basin. The defining of water quality standards and their observance may significantly affect the quantity of water considered as available for use. The introduction of a polluter pays tax would then be possible.

If they were sure that the water would actually go to the Aral Sea, the upstream countries would be ready to release more water. One important measure for the future would be to consider the Aral Sea and the two deltas as a sixth entity, in addition to the five Central Asian republics, to which a water allocation should be given. In the round of discussions between the countries, a figure of 20 km³/year in normal humid years has been advanced for this environmental water demand, reduced to 12 km³/year in the one dry year out of ten.

All these options and solutions have been studied for the regional water strategy exercise, which is the result of a cooperation of the riparian countries. This has been made possible by the setting up of an institutional framework to address the Aral Sea problem through selected national macro-economic and sectoral policies for achieving sustainable land, water and other natural resources development. This institutional framework currently includes only the countries of the FSU. However, Afghanistan, which covers about 12% of the Aral Sea basin, will probably become a greater water user as its stability increases, so reducing the flow of the Amu Darya tributaries accordingly. At a later stage, Afghanistan should be included in the agreements regarding the Aral Sea basin in order to guarantee sustainable water resources management in the basin.

Thematic maps