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 of Southeast Turkey. The presence of European beaver has been attested in the bone assemblage of the prehistoric site of Abu Hureyra in Syria, but the beaver has never been sighted in historical times. The Hindiya Barrage on the Iraqi Euphrates, based on plans by British civil engineer William Willcocks and finished in 1913, was the first modern water diversion structure built in the Tigris–Euphrates river system. The Hindiya Barrage was followed in the 1950s by the Ramadi Barrage and the nearby Abu Dibbis Regulator, which serve to regulate the flow regime of the Euphrates and to discharge excess flood