Mohale Tunnel

Mohale Tunnel
The Mohale Tunnel is part of Phase 1B of the Lesotho Highlands Water Project and is designed to transfer an averag of 9.5 m³/s from the Mohale Reservoir to the Katse Reservoir.
Client:
Lesotho Highlands Development Authority, Maseru
Period:
1983 - 2005
Services:
  • Feasibility study 1983 - 1986
  • Tender design 1995 - 1997
  • Construction supervision and detailed design 1997 - 2005
Technical data:
Water Conveyance Tunnel from Mohale Reservoir to Katse Reservoir
  • Length/inner diameter: 32 km/4.00 m
  • Discharge: 9.5 m³/s average
  • Maximum cover: 1,150 m
  • Rock formation: basalt lava flows
  • Lining: precast concrete segmental lining with 0.25 thickness
  • Excavation method: double shielded telescopic TBM
  • Excavation diameters: 4.88 m and 5.38 m
Department
Water
Spectrum
Geotechnical Engineering, Geology and Dams
Country
Lesotho