Merowe Dam: Details of Site & Engineering Design Suzanne Young February 19, 2004

Outline Project aims Details of site Main Nile Climate Topography & Geology Engineering Design

What are the project aims? Eliminate current deficit in electricity in Sudan Satisfy future demand Contribute to industrial and agricultural development  employment Raise standard of living for citizens

The Main Nile Khartoum to Wadi Halfa, 1500 km Large S bend Most significant feature: Cataracts 1979 – no river, control or storage works Effect of Aswan High Dam

Climate July to August, Northern Sudan’s rainy season 50 mm, Merowe’s mean annual rainfall High variability Intensity of storms Hot summers (34 C) and cold winters (20 C)

Geology Between third & fourth cataract, sandstone channel 100 km below fourth cataract, broad, silty floodplains Between fourth & fifth cataract, narrow bed of tough igneous and metamorphic rocks

Design origin, basis 1979 study led to design proposals Merowe dam Long in relation to height Extended & elaborate spillway structures Concrete structure in main river channel, rockfill dyke on each bank

Cont. Control floods using surface spillways and deep sluices Sluices permit drawdown in dry season if necessary Sluices used for partial drawdown prior to floods

Merowe Dam Overview Located 350 km (220 mi) north of Khartoum Installed capacity: 10 units of 125 MW – 1250 MW Approx. 10 km long, 65 m high Reservoir, 170 km long, 476 square km surface area

Dam structures Dam of ~65 m height consist of: Concrete faced rockfill dam (right bank), ~4,800 m long Rock and earthfill dam (left bank), ~4,000 m long Concrete dam ~520 m long, including powerhouse for 10 turbines, spillway and sluices

Helpful dam terminology Cofferdam Temporary dam built to keep riverbed dry to allow construction of permanent dam Drawdown The lowering of a reservoir’s surface elevation and water volume by releasing (spilling or generating) the reservoir’s water at a rate greater than the rate at which water flows into the reservoir Sluice A structure with a gate for stopping or regulating flow of water

Dam figures Look at and discuss!