How the Aral Sea was turned into an ecological disaster - and might now be saved from still further damage, if never fully restored - is documented in a recent survey by AG's Land and Water Development Division (AGL) of irrigation development in 15 countries of the former Soviet Union.
In the 1960s, planners assigned Central Asia the role of supplier of raw materials, notably cotton. Given the region's arid climate, irrigation was imperative, and the Aral Sea and its tributaries seemed a limitless source of water. Irrigation development in the Soviet part of the Aral Sea basin was spectacular, expanding from an area of about 4.5 million ha in 1960 to almost 7 million ha in 1980. Local population also grew rapidly, from 14 million to about 27 million in the same period, while total water withdrawal almost doubled to 120 cubic km, more than 90% of it for agriculture.
The result was what water resource experts call "disruption of the prevailing water balance" in the Aral basin. Many minor tributaries were so overexploited that they ceased to contribute directly to the flow of the Amu Darya and Syr Darya. Low irrigation efficiencies - caused by unlined canals and a poor drainage network - led to major waterlogging and salinization that eventually affected about 40% of irrigated land. Overuse of pesticides and fertilizer polluted surface- and groundwater, while the delta ecosystems have simply perished: by 1990, more than 95% of the marshes and wetlands had given way to sand deserts, and more than 50 delta lakes, covering 60 000 ha, had dried up.
Desertification, climate change. The Aral Sea, too, is drying up, its level having dropped from 53m above sea level to 36m, its surface area shrinking by a half and its volume by three-quarters. Today, the sea survives in three sections: the Small or Northern Sea in Kazakhstan, the Central Sea, and the Western Sea, mostly located in Uzbekistan. The mineral content of the water has increased fourfold to 40 g/litre, preventing the survival of most of the sea's fish and wild life. All commercial fishing ended in 1982, current fish hauls are negligible, and entire fishing communities are now unemployed. Former seashore villages and towns are 70 km away from the present shoreline. The exposed seabed consists of vast salt tracts, whose sand and dust, polluted with pesticides, are carried by the wind up to a distance of 250 km at an estimated rate of 15 to 75 million tonnes a year.
Communities face appalling health problems. In Karakalpakstan, drinking water is saline and polluted, with a high content of metals - such as strontium, zinc and manganese - that cause conditions such as anaemia. The last 15 years has seen a 3,000% increase in chronic bronchitis and in kidney and liver diseases, especially cancer, while arthritic diseases have increased 6,000%. Not surprisingly, the infant mortality rate is one of the world's highest.
Regional water strategy. As early as the 1982, the government sought to develop a water resources master plan for the Syr Darya and Amu Darya river basins and placed strict limits on water withdrawal. Soon after, two basin water organizations were created to operate and maintain the main hydraulic infrastructures and to monitor water use. With the end of the Soviet period, five newly independent Central Asian states established a joint commission for water coordination to regulate water distribution in the basin and consolidate country positions for the adoption of a regional water strategy. Several international organizations and bilateral agencies are supporting the preparation of this strategy, as well as regional studies and pilot projects for a new approach in water management, and an International Fund for the Aral Sea and the Interstate Council for the Aral Sea Problem have been set up to coordinate these initiatives regionally.
But what is being done now to save the Aral Sea, at least from further degradation? Among proposals currently under study is transfer of water to the Aral from the Caspian Sea. Greater use of agricultural drainage water and wastewater, as well as the introduction of more salt-tolerant crops, is envisaged and, in part, implemented. About 6 cubic km/year of agricultural drainage waters or wastewater are directly re-used for irrigation, while some 37 cubic km/year return to natural depressions or rivers where they are mixed with freshwater and can be re-used for irrigation or other purposes.
Although these improvements have enabled further irrigation development, they are viewed as unsustainable. The five Central Asian republics have decided to focus now on demand management, aiming to reduce water withdrawal per hectare by raising global irrigation efficiency: this involves canal rehabilitation and lining, which reduces losses, and canal regulation for better irrigation scheduling. The primary objective remains satisfying crop water requirements and, in view of the very limited funds available, measures will be implemented gradually and rely mostly on international assistance.
Several countries have introduced water fees and fines for use of water in excess of farm allocation, and turned over to farmers decision making on crops to be grown on irrigation schemes. As a result, crops with high water requirements - rice in Kazakhstan and cotton in Turkmenistan and Uzbekistan - have been partially replaced by other, less demanding crops. These changes may lead to a reduction in water withdrawals, but make planning and monitoring water distribution more difficult.
Future prospects. Much progress has been made since 1990. The total water withdrawal in the basin has now stabilized at about 110-120 cubic km/year (it was about 65 in 1960). However, further improvement is needed to meet increasing demand from new water users.
Promising signs are reported in the Amu Darya delta and Western Sea - since 1989, a project in Uzbekistan has used the collector-drainage network to bring more water to the delta. This water, combined with freshwater, replenishes shallow lakes and has allowed re-development of flora and wildlife in the abandoned areas, and stopped wind erosion of the formerly exposed seabed. Another result of this project has been higher annual fish catches, estimated at 5,000 tonnes in 1993, up from 2,000 tonnes in 1988.
Because the water resources of the basin are now more or less stable, or decreasing slightly due to climatic change, action is needed to save all additional water flowing to the Aral Sea from upstream existing uses. The AGL study says a major programme is needed to reduce losses in the rivers and canals, mainly by lining and automatization of distribution, to stop irrigation expansion, to generalize micro-irrigation and other water saving techniques on existing irrigated areas, to redirect drainage water and other spilled reservoir and canal water directly to the sea, and to return also the non-consumed fraction of the water diverted into irrigation schemes. According to the World Bank, the introduction of a water market could also help save more water.
Aral a "sixth state"? 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, upstream countries would be willing to release more water, the study concluded. One important measure for the future would be to consider the Aral Sea and the two deltas as a "sixth state" with a water allocation from the five Central Asian republics. In the round of discussions between the countries, a figure of 20 cubic km/year in normal wet years has been advanced for this environmental water demand, reduced to 12 cubic km/year in the one dry year out of 10.
All these options and solutions have been studied as part of the regional water strategy which, however, involves only the countries of the former Soviet Union. At a later stage, Afghanistan - which covers about 12% of the Aral Sea basin - would be included in the agreements in order to guarantee sustainable water resources management.
Published September 1998