Both the Aral Sea in Central Asia and the Salton Sea in Southern California are in their present states as the result of man-made water diversions. The Salton Sea was created by a water diversion in 1905, and mandated water transfers since then have decreased its inflow, producing salinity levels that have resulted in fish kills, exposed sections of dry lake bed and produced dust storms. In Central Asia, the Aral Sea has dried up almost completely as a result of the two rivers feeding it being diverted to irrigate nearby rice and cotton fields.
The Aral Sea, which was once the fourth-largest inland water body worldwide, has shrunk by about 75 percent. Water diversions, sometimes exceeding natural flows, were made to the rivers feeding the Aral Sea to develop a cotton-based agricultural economy in what was once part of the former Soviet Union. The result was a major reduction of the Aral Sea's inflow sources that exposed vast areas of lake bed and caused dust storms resulting in high respiratory-disease mortality rates. What is left of the Aral Sea has tripled in salinity, and it has also become severely polluted from pesticides and industrial wastes.
The creation of the Salton Sea was an unplanned event when California engineers dug irrigation canals into the Colorado River in 1905. The water flow unexpectedly overwhelmed the canal system and poured into a dry lake bed, creating the modern Salton Sea and submerging the nearby town of Salton. In 2003, inflows to the Salton Sea were diverted for irrigation and further inflow decreases are planned for 2018. Concerns exist that the inflow reductions will cause the Salton Sea to shrink by more than 50 percent, expose thousands of acres of lake bed, and raise the levels of unhealthy dust blowing throughout the area.