(yōfrā'tēz), Turkish Frat, Arabic Al Furat, river of SW Asia, c.1,700 mi (2,740 km) long, formed by the confluence of the Kara and the Murad rivers, E central Turkey, and flowing generally S through Turkey into Syria, then SE through Iraq, joining with the Tigris River in SE Iraq to form the Shatt al Arab; the united river flows into the Persian Gulf. The Euphrates is unnavigable except for very shallow-draft vessels; a drainage project was begun in the 1960s involving the construction of a 342 mi (550 km) canal running between the Tigris and Euphrates to serve as a route for river barges.
In its upper course, the Euphrates flows rapidly through deep canyons and narrow gorges, and Turkey has constructed dams on the upper river and its tributaries since the 1970s. In 1990, the Atatürk Dam, the first in the Southeast Anatolia Project in Turkey, was completed. Plans ultimately call for 22 dams on the Tigris and Euphrates that altogether will provide enough water to irrigate over 3,700,000 acres (1.5 million hectares) of land. A series of hydroelectric power stations is also being built; by 2014 more than half the dams had been completed. This huge diversion of water in Turkey has had serious implications for Syria and especially Iraq, which also rely on the river.
The middle Euphrates traverses a wide floodplain in Syria, where it is used extensively for irrigation. Euphrates Dam, 230 ft (70 m) high, constructed with Soviet aid at Tabqa, N Syria, is the main unit of the Tabqa Barrage Scheme. The huge reservoir impounded by the dam provides electrical power but has failed to transform the region into a productive agricultural area. Below the dam the Euphrates receives the Belikh and Khabur rivers, its only major tributaries.
Entering the Syrian Desert and the plains of Iraq, the river loses velocity and becomes a sluggish stream with shifting channels. In N Iraq it is studded with islands, some with remains of old castles. The river's lower course supplies water through a system of dams and canals to allow wheat and barley cultivation, but since the first Turkish and Syrian dams were constructed in the 1970s the amount of water the river carries into Iraq has declined by two thirds. Flooding and overirrigation have resulted in serious problems of soil salinization. Before merging with the Tigris at Basra, Iraq, the Euphrates divided into many channels, forming a marshland and Lake Hammar. The marshes were drained in the early 1990s to increase Iraqi government control over the Shitte Marsh Arabs living there; restoration of the marshes began in 2003, and roughly 75% of the wetlands were restored. Drought and water losses, however, have reduced the size of the marshes.
The modern waterworks along the Euphrates do not equal in scope those of ancient times when Sippar, Uruk, Ur, and Babylon flourished on the banks of the lower Euphrates. Mesopotamia, birthplace of many great civilizations, depended on the waters of the Euphrates and the Tigris for survival. However, as the maintenance of irrigation and drainage networks was neglected, the siltation of canals and the salinization of fields eventually made the land unsuitable for agriculture.