Tigris–Euphrates river system Tigris–Euphrates river system The Tigris and Euphrates, with their tributaries, form a major river system in Western Asia. From sources originating in eastern Turkey, they flow by/through Syria through Iraq into the Persian Gulf. The system is part of the Palearctic Tigris–Euphrates ecoregion, which includes Iraq and parts of Turkey, Syria, Iran, Saudi Arabia, Kuwait, and Jordan. From their sources and upper courses in the mountains of eastern Anatolia, the rivers descend through valleys and gorges to the uplands of Syria and northern Iraq and then to the alluvial plain of central Iraq. The rivers flow in a south-easterly direction
Euphrates water into the depression that is now Lake Habbaniyah. Iraq's largest dam on the Euphrates is the Haditha Dam; a earth-fill dam creating Lake Qadisiyah. Syria and Turkey built their first dams in the Euphrates in the 1970s. The Tabqa Dam in Syria was completed in 1973 while Turkey finished the Keban Dam, a prelude to the immense Southeastern Anatolia Project, in 1974. Since then, Syria has built two more dams in the Euphrates, the Baath Dam and the Tishrin Dam, and plans to build a fourth dam – the Halabiye Dam – between Raqqa and Deir ez-Zor. The Tabqa