Even before Kyrgyzstan and Tajikistan began their recent push to build hydroelectric dams along Central Asia's two main rivers, downriver countries were coping with water scarcity challenges caused by increased demand and inefficient agricultural practices. During the Soviet era, the Amu Darya and the Syr Darya rivers, which feed into the Aral Sea, were tapped for irrigation. The two rivers are sourced largely from snowmelt and glacial thaw in the mountains of Tajikistan and Kyrgyzstan, keeping flows from the rivers' headwaters relatively consistent over the past 50 years. However, large-scale irrigation schemes geared toward cotton production have prevented water from reaching the Aral Sea, causing its volume to decrease by about 75 percent since the 1960s. Adjusting irrigation techniques in Kazakhstan, Turkmenistan and Uzbekistan could partially mitigate these problems, but political and economic difficulties in these countries — especially the latter two — could stymie any progress. The persistence of water competition in Central Asia has already increased regional tensions and could eventually escalate to armed conflict if the situation goes unaddressed.