Merowe Dam: Details of Site

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Merowe Dam Details of Site Engineering Design

• Suzanne Young
• February 19, 2004

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Outline

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

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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

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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

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Climate

• July to August, Northern Sudans rainy season
• 50 mm, Merowes mean annual rainfall
• High variability
• Intensity of storms
• Hot summers (34 C) and cold winters (20 C)

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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

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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

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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

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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

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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

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Helpful dam terminology

• Cofferdam
• Temporary dam built to keep riverbed dry to allow
  construction of permanent dam
• Drawdown
• The lowering of a reservoirs surface elevation
  and water volume by releasing (spilling or
  generating) the reservoirs 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

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Dam figures

• Look at and discuss!