II.

Course of the Euphrates

The bed of the Euphrates, as it nears the sea, is now a large marshland, overgrown with submarine vegetation. The river is navigable for a distance of about 720 km (450 mi) inland from its mouth by small boats. Although the water level is enhanced by locks and a canal, the depth may drop to as low as 61 cm (24 in) during the dry season, between December and March.

Though less than 30 per cent of the basin is in Turkey, roughly 94 per cent of the water of the Euphrates comes from there, including the flows of the Karasu, the Murat, and other Turkish rivers, which join near Elâzığ to form the upper Euphrates. The Euphrates reaches Syria approximately 120 km (75 mi) north-east of the city of Aleppo (Ḩalab). In Syria it is joined by the River Khābūr, a major tributary whose water rises in south-eastern Turkey and north-eastern Syria.

The course of the Euphrates roughly parallels that of the Tigris; after both rivers cross into Iraq they are never more than 160 km (100 mi) apart. Flowing towards their junction in south-eastern Iraq near Basra, the Euphrates forms the western boundary of the area known as al-Jazirah, or the Island. After its confluence with the Tigris the combined flow is known as the Shatt Al Arab.