The Merowe Dam, also known as Merowe High Dam, Merowe Multi-Purpose Hydro Project or Hamdab Dam, is a large dam near Merowe Town in northern Sudan, about north of the capital Khartoum. Its dimensions make it the largest contemporary hydropower project in Africa. It is situated on the river Nile, close to and inundating the 4th Cataract where the river divides into multiple smaller branches with large islands in between. Merowe is a city about downstream from the construction site at Hamdab. The main purpose for building the dam was the generation of electricity. Technical details The dam has a length of about and a crest height of up to . It consists of concrete-faced rockfill dams on each river bank (the right bank dam is the largest part of the project, 4.3 km long and 53m high; the left bank is 1590 metres long and 50 metres high), an -long -high earth-core rockfill dam (the 'main dam') in the left river channel, and a live water section in the right river channel (sluices, spillway and a 300-metre power intake dam with turbine housings). It contains a reservoir of , or about 15% of the Nile's annual flow of ; the intended reservoir level is 300 metres above sea level, with the Nile level downstream of the dam being about 265 metres. The reservoir lake is planned to extend upstream. Powerhouse The powerhouse is equipped with ten Francis turbines, each one designed for a nominal discharge rate of 300 cubic metres per second, and each one driving a , synchronous generator. The planners expect an annual electricity yield of , corresponding to an average load of , or 50% of the rated load. To utilize the extra generation capacity, the Sudanese power grid will be upgraded and extended as part of the project, with about of new aerial transmission line across the Bayudah Desert to Atbara, continuing to Omdurman/Khartoum, as well as about of lines eastwards to Port Sudan and westwards along the Nile, connecting to Merowe, Dabba and Dongola. Planning and construction The idea of a Nile dam at the 4th cataract is quite old. The authorities of the Anglo-Egyptian Sudan proposed it several times during the first half of the 20th century. It was supposed to equalize the large annual Nile flow fluctuations, create the possibility of growing cotton and provide flood protection for the lower Nile valley.