dam on the Euphrates River in north-central Syria. The dam, which is located 30 miles (50 km) upriver from the town of Ar-Raqqah, was begun in 1968. Its construction prompted an intense archaeological excavation of the area around the town of Ṭabaqah. The dam is of earth-fill construction, some 197 feet (60 m) high and 2.8 miles (4.5 km) long. It was completed in 1973, and the reservoir behind the dam, Lake Assad, began filling. The lake at its fullest extent is approximately 50 miles (80 km) long and averages 5 miles (8 km) in width. The accompanying power plant was completed in 1977. Electrification subsequently reached to even the remotest villages in Al-Jazīrah (the area to the east of the Euphrates). Several irrigation schemes are associated with the project.