Euphrates - River Modifications

River Modifications

The Hindiya Barrage on the Iraqi Euphrates, based on plans by the 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 water into the depression that is now Lake Habbaniyah. Iraq’s largest dam on the Euphrates is the Haditha Dam; a 9-kilometre (5.6 mi) long 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 Ar-Raqqah and Deir ez-Zor. The Tabqa Dam is Syria's largest dam and its reservoir (Lake Assad) is an important source of irrigation and drinking water. It was planned that 640,000 hectares (2,500 sq mi) should be irrigated from Lake Assad, but in 2000 only 100,000–124,000 hectares (390–480 sq mi) had been realized. Syria also built three smaller dams on the Khabur and its tributaries.

With the implementation of the Southeastern Anatolia Project (Turkish: Güneydoğu Anadolu Projesi, or GAP) in the 1970s, Turkey launched an ambitious plan to harness the waters of the Tigris and the Euphrates for irrigation and hydroelectricity production and provide an economic stimulus to its southeastern provinces. GAP affects a total area of 75,000 square kilometres (29,000 sq mi) and approximately 7 million people; representing about 10 percent of Turkey's total surface area and population, respectively. When completed, GAP will consist of 22 dams – including the Keban Dam – and 19 power plants and provide irrigation water to 1,700,000 hectares (6,600 sq mi) of agricultural land, which is about 20 percent of the irrigable land in Turkey. Circa 910,000 hectares (3,500 sq mi) of this irrigated land is located in the Euphrates basin. By far the largest dam in GAP is the Atatürk Dam, located circa 55 kilometres (34 mi) northwest of Şanlıurfa. This 184-metre (604 ft) high and 1,820-metre (5,970 ft) long dam was completed in 1992; thereby creating a reservoir that is the third-largest lake in Turkey. With a maximum capacity of 48.7 cubic kilometres (11.7 cu mi), the Atatürk Dam reservoir is large enough to hold the entire annual discharge of the Euphrates. Completion of GAP was scheduled for 2010 but has been delayed because the World Bank has withheld funding due to the lack of an official agreement on water sharing between Turkey and the downstream states on the Euphrates and the Tigris.

Apart from barrages and dams, Iraq has also created an intricate network of canals connecting the Euphrates with Lake Habbaniyah, Lake Tharthar, and Abu Dibbis reservoir; all of which can be used to store excess floodwater. Via the Shatt al-Hayy, the Euphrates is connected with the Tigris. The largest canal in this network is the Main Outfall Drain or so-called "Third River;" constructed between 1953 and 1992. This 565-kilometre (351 mi) long canal is intended to drain the area between the Euphrates and the Tigris south of Baghdad to prevent soil salinization from irrigation. It also allows large freight barges to navigate up to Baghdad.