Tarbela Dam, on the Indus River in Pakistan, is the largest earth filled dam in the world and second largest by structural volume. It is located in Haripur District, Khyber Pakhtunkhwa, about 50 kilometres (31 miles) northwest of Islamabad, near Topi. The dam is 485 feet (148 m) high above the riverbed. The dam forms the Tarbela Reservoir, with a surface area of approximately 250-square-kilometre (97 sq mi). The dam was completed in 1976 and was designed to store water from the Indus River for irrigation, flood control, and the generation of hydroelectric power.