Tarbela Dam

Tarbela Dam is an earth fill dam on the Indus River in Pakistan. It's the largest earth-filled dam in the world and fifth-largest by structural volume. It is named after the town Tarbela, in Khyber Pakhtunkhwa, about 50km northwest of Islamabad.The dam is 485ft high above the riverbed. It forms the Tarbela Reservoir, with a surface area of approximately 250km2. 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.Its primary use is electricity generation. The installed capacity of the 3,478 MW Tarbela hydroelectric power stations will increase to 6,298MW after completion of the ongoing fourth extension and the planned fifth extension financed by Asian Infrastructure Investment Bank and the World Bank.Project descriptionThe project is at a narrow spot in the Indus River valley, at Tarbela between Haripur District and Swabi District, approximately 60 kilometers northwest of Islamabad.The main dam wall, built of earth and rock fill, stretches 2743m from the island to river right, standing 148m high. A pair of concrete auxiliary dams spans the river from the island to river left. The dam's two spillways are on the auxiliary dams rather than the main dam. The main spillway has a discharge capacity of 18406m3/s and the auxiliary spillway, 24070m3/s. Annually, over 70% of water discharged at Tarbela passes over the spillways and is not used for hydropower generation.