Euphrates Turkey, in Syria and in Iraq. The same figures are given by Isaev and Mikhailova. The length of the Shatt al-Arab, which connects the Euphrates and the Tigris with the Persian Gulf, is given by various sources as . Both the Kara Su and the Murat Su rise northwest from Lake Van at elevations of and amsl, respectively. At the location of the Keban Dam, the two rivers, now combined into the Euphrates, have dropped to an elevation of amsl. From Keban to the Syrian–Turkish border, the river drops another over a distance of less than . Once the Euphrates
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