In some cases like Turkmenistan, investments are being made in reverse osmosis systems. The distribution of water resources in Central Asia is shaped by the region's physical geography. The region consists of low-lying desert terrain bordered on the south and southeast by very high mountain ranges. The Tyan Shan Mountains form part of its eastern border with China's Xinjiang Province. The world's highest-latitude deserts, the Kyzl Kum and Kara Kum, form much of the rest of the northern and middle part of Central Asia.
Summers are hot and winters are generally cool or cold.
Regional precipitation varies from 100 mm per year in the deserts to 300 mm in the foothills to the south and east. The bulk of Central Asia's 55 million people, and therefore, most cities and urban settlements, are located along the slopes of the mountains and are supported mainly by surface water diversions from rivers and streams rising in the mountains and flowing into the Central Asian basin. The largest of these rivers, the Amu Darya and the Sur Darya, flow northwestward into the Aral Sea. Lesser streams eventually disappear in the hot desert sands. Cities in Central Asia obtain their water mainly from surface diversions, although a few supplement surface diversions with some groundwater development.