Euphrates Dam

The dam lies immediately north of the city of Al-Thawrah (Tabqa), about 40 km upstream of Raqqa (other sources: 35 or 50 km). It is 4.5 km long, 60 m high above the riverbed, 512 m wide at the base and 19 m at the crest. A 250 m spillway with two openings serves as flood relief. The hydroelectric station at the southern end has eight Kaplan turbines of up to 103 MW each; the German Wikipedia gives an installed capacity of 824 MW.

The reservoir – Euphrates Lake, called Lake Assad in the German Wikipedia – is about 80 km long and on average 8 km wide. Its potential capacity is given as 11.7 km³; the actual capacity is given as 9.6 km³ with a surface of 447 km².[1][2][3]

A Euphrates dam was first proposed in 1927 under the French Mandate. After agreements with the Soviet Union (1957), with West Germany on a loan (1960) and again with the Soviet Union (1965), construction began in 1968. It lasted until 1973 (German Wikipedia: 1974); the power station was completed on 8 March 1978. The cost was US$340 million, of which US$100 million was a Soviet loan; up to 12,000 Syrians and 900 Soviet technicians worked on the project. According to the English Wikipedia, around 4,000 Arab families from the flooded valley were resettled as part of a partially implemented plan for an "Arab belt" along the borders.

Filling the reservoir from 1974, as Turkey filled the Keban Dam during a drought, led to a dispute with Iraq; both states sent troops to the border. An agreement was reached in 1975 through Saudi and Soviet mediation.

On 11 February 2013 opposition forces took the dam (German Wikipedia: rebels around the Nusra Front), and in 2014 the Islamic State. During an SDF–US operation on 26 March 2017 US bombs struck the facility; critical equipment failed and the dam stopped functioning. After an emergency ceasefire, repairs were made and floodgates opened on 29 March and 5 April; the flooding displaced about 3,000 people. The SDF took the dam on 10 May 2017. In January 2026 government forces took control (ar: evening of 17 January; en, citing SANA: 18 January).[1][2][3]

The planning goals were only partly met: of 640,000 ha intended for irrigation, about 124,000 ha (19%) were irrigated in 2000, partly due to gypsum-rich, salinising soils and collapsed canals. Because of lower inflow from Turkey and lack of maintenance, the English Wikipedia states that the plant generates only 150 MW instead of 800 MW. The lake is Aleppo's most important source of drinking water and supports fishing; its shores are a wintering area for migratory birds, and the island of Jazirat al-Thawra is a nature reserve.

Before flooding, sites were surveyed from 1963, and an international rescue programme, supported by UNESCO from 1971, excavated more than 25 of them, among them Mureybet, Emar and Abu Hureyra; the minarets of Mureybet and Meskene were moved and the castle of Qal'at Ja'bar was protected.[1][2][3]