Ecological legacies: environmental impacts of unsustainable water management
The overuse of water with ignorance of ecological limits and poor management during the Soviet period have since led to severe ecological consequences that the independent states have to face, the gravest being that 80% of the Aral Sea has turned into a desert. In addition, most of the irrigated land is plagued by salinization, waterlogging and water erosion. In the regions close to the Aral Sea, about 90% of the land is affected by salinization. The decay of soil quality requires additional large volumes of water to rinse away the salt and still reduces fertility. The regions at the middle and lower reaches of the big rivers suffer from water scarcity. The inflow of drainage water heavily contaminated with nitrates, organic fertilizers, and phenol has polluted the ground water. In the downstream regions of the Syr and Amu Darya, the provinces of Kyzylorda in Kazakhstan, Dashhoguz in Turkmenistan as well as Khorezm and Karakalpakstan in Uzbekistan, water is so polluted that it is unsuitable for either drinking or irrigation. At the Syr Darya, another potential health threat is radioactive pollution. Several uranium dumping sites are located close to the tributaries and are subjected to landslides.[MKUR 2006, Bucknall et al. 2003.]
Decades of overuse of water in agriculture have shaped infrastructure, economic dependencies, social structures, usage patterns and traditions that are not easy to change. Therefore, these usage patterns continue to exist and have an impact even today. As described, during Soviet times water consumption did not have to be paid on a quantitative basis. Thus there were no economic incentives to limit consumption. This behaviour was aggravated by the Soviet ideology of human control over nature, which posits that nature is a mere means for human development and may thus be fully exploited. In addition, deteriorated infrastructure and inefficient irrigation techniques led to high water consumption. Instead of directing the water through closed pipes, water evaporates in open channels or trickles into earthen channels that are not lined. Outdated irrigation techniques with high water consumption and a high evaporation rate on the fields are still applied. The water loss from the huge Karakum Canal, with its unprotected banks, is estimated at one to two-thirds of the total flow.[Giese et al. 2004.] As a consequence, Central Asia has the lowest water use efficiency worldwide.[UNDP 2006.] Experts estimate that 50% to 80% of irrigation water is lost before reaching the fields.[EuropeAid 2010, World Bank 2004.] This leads to water use as high as 12 200 cubic metres per hectare-UNECE assesses water use in cotton irrigation even with up to 14 400–16 600 m3/ha. The following table shows that even compared with countries like Egypt or Turkey (themselves not the most efficient water users), per capita water use in Central Asia is considerably higher.[Bucknall et al. 2004, EuropeAid 2010, UNDP 2006, UNECE 2004.]
The main reasons for water scarcity in Central Asia are hence anthropogenic and rooted in wasteful overconsumption. This can actually be viewed as an opportunity. If water scarcity is a result of human activities, then we can improve the situation if we change our behaviour to more sustainable water usage and management.