Tigris–Euphrates river system border. Since the 1960s and in the 1970s, when Turkey began the GAP project in earnest, water disputes have regularly occurred in addition to the associated dam's effects on the environment. In addition, Syrian and Iranian dam construction has also contributed to political tension within the basin, particularly during drought. The general climate of the region is subtropical, hot and arid. At the northern end of the Persian Gulf is the vast floodplain of the Euphrates, Tigris, and Karun Rivers, featuring huge permanent lakes, marshes, and forest. The aquatic vegetation includes reeds, rushes, and papyrus, which support numerous species. Areas
Water supply and sanitation in Iraq of Iraq. These two rivers account for 98% of Iraq`s surface water supply. Their flow is therefore very vulnerable to dams and water diversions in Turkey, Syria and Iran. The Euphrates does not receive water from permanent tributaries within Iraq territory and is fed only by seasonal runoff from wadis. The average annual flow of the Euphrates at the border to Turkey is estimated at 30 km³, with a fluctual annual value ranging from 10 to 40 km³. The Tigris has an average annual runoff of 21.2 km³. Within Iraq, the Tigris River receives water from five main tributaries, namely