Lesotho

Selected Project Experience

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Client:
Lesotho Highlands Development Authority (LHDA)

Location:
Lesotho

GIBB’s Responsibilities:
The Lesotho Highlands Water Project (LHWP) is a multi-billion Maloti/Rand bi-national project which was established by the treaty of 1986 between the governments of the Kingdom of Lesotho and the Republic of South Africa.

The LHWP includes large scale civil engineering, socio-economic and environmental components. The LHWP harnesses the water resources of the highlands of Lesotho through the construction of a series of dams and tunnels for the mutual benefit of Lesotho and South Africa.

Phase II of the project has commenced. GIBB’s tasks on Phase II of the project include a 163.5 m concrete-faced rockfill dam at Polihali, downstream of the confluence of the Khubelu and Senqu (Orange) Rivers, and a gravity tunnel that connects Polihali Reservoir to the Katse Reservoir.  This is currently underway.

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Client:
Lesotho Highlands Development Authority (LHDA)

Location:
Lesotho

GIBB’s Responsibilities:
This project was awarded to GIBB with the objective of identifying additional hydropower in Lesotho.  GIBB’s services included: project management; contract administration; quality management; risk management; progress monitoring and reporting, and assistance to the client.

The specific scope of work includes: conventional hydropower feasibility review; screening study of viable conventional hydropower options (both within and out of the Lesotho Highlands Water Project, LHWP); review of the existing and projected Lesotho electrical system; generation capacity and power demand; analysis of viable small or medium hydropower options within the existing LHWP system; review of the existing and planned expansion of the Lesotho transmission and distribution network; review of options for the expansion of Muela hydropower station;  conduct of pre-feasibility screening study of other viable hydropower options in Lesotho (outside the LHWP);  conduct of economic assessment of hydropower options and comparison with alternative energy sources (e.g. wind power).

GIBB also conducted final engineering studies, including: revised cost estimate; project development programme; due diligence review of the relevant Lesotho legal and regulatory framework; assessment of financing requirements; geotechnical site investigation; environmental & social studies and various project development options.

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Location:
Maseru and surrounding areas, Lesotho

GIBB’s Responsibilities:
GIBB (Pty) Ltd was appointed as the Project Management Consultant (PMC) to provide services for the Urban and Peri-Urban Water Supply Activities through the Defects Notification Period (DNP). These projects focused on rehabilitation and expansion of the existing urban water infrastructure in 10 urban centres around the country and construction of a new water supply system in Semonkong town. The project was composed of five packages:

Package 1 – Maseru and Mazenod.
Package 2 – Semonkong.
Package 3 – Mafeteng, Mohale’s Hoek, Quthing, and Qacha’s Nek.
Package 4 – Leribe, Butha-Buthe, and Mokhotlong.
Package 5 – Mapoteng.

The services included to oversee small works contracts in the Packages 2, 3, 4, and 5, and also providing Technical Assistance in operation and maintenance for both facilities and personnel.

Metolong Dam and Pump Station – Detailed Design and Construction Supervision Dams/Pipelines

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Client:
Metolong Authority

Location:
Metolong, Lesotho

GIBB’s Responsibilities:
The Metolong Dam Project is an 83 m high straight Roller Compacted Concrete (RCC) gravity dam with a storage capacity of 63.7 million m3. The downstream face is stepped to suit the RCC construction method and has a slope of 0.8:1 (H:V).

The project included a multi-level intake tower and a raw water pumping station with a capacity of 1.2 m3/s, with provision made for the capacity to be increased to 2.4 m3/s. The project formed part of the water supply programme that was identified as the next long term solution to meet increasing water demands in the Lesotho Lowland.

GIBB as the consultant covered the tender and detail design of the dam, intake tower and pumping station, and provided supervision of construction.

metolong-downstream-conveyance-system

Client:
Metolong Authority

Location:
Lesotho

GIBB’s Responsibilities:
GIBB, as lead partner in a Joint Venture, was appointed for the construction supervision of the downstream conveyance system, which forms a portion of the overall Metolong Dam and Water Supply Programme.

The downstream conveyance system consists of a system of pipelines totalling approximately 132 km, as well as associated appurtenances and pump stations. Included were storage reservoirs for conveyance of potable water to several communities of Maseru.

Tasks were split into three contracts; Contract 1 included the primary line from near the command reservoir at the water treatment works (WTW) and the Mpilo Reservoir in Maseru, and the Metolong Connector. Contract 2 included secondary lines with pump station, tanks and all appurtenances.

Contract 3 included a secondary line from the command reservoir near the WTW to the Teyateyaneng community, including tanks, pump station and appurtenances.

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Location:
Near Butha-Buthe, Lesotho

GIBB Responsibilities:
GIBB, in a Joint Venture with EDF, URS, Royal HaskoningDHV and Knight Piésold and supported by local firm GWC, was appointed to undertake a pre-feasibility study of the Monontsa Pumped Storage Scheme.

The Monontsa Pumped Storage Scheme is located in 38km North East of the town Butha-Buthe in Lesotho. The upper reservoir is located on the Tsehlanyane River (which drains southwards as part of the headwaters of the Katse Dam) and the lower reservoir on the North flowing Pitseng River. The distance between the upper and lower reservoirs is approximately 5.2 km and the elevation difference approximately 695 m.

The capacity of the scheme installed was 1200 MW with a continuous generating period of  21 hours. The underground powerhouse complex consists of a machine hall, a transformer hall, access and construction tunnels.

The pump/turbines are connected to the upper reservoir by a concrete lined headrace tunnel and pressure tunnel that is partially steel lined in the immediate vicinity of the power house. A concrete lined extended draft tube and tailrace tunnel connect the pump/turbines to the lower reservoir.

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Client:
Government of Lesotho

Location:
Lesotho

GIBB’s Responsibilities:
GIBB was appointed to be the design engineers for the Mantsonyane-Lesobeng Road in Lesotho. Specific tasks included bridge engineering; geometric design; pavement engineering; drainage and stormwater engineering, and flood protection engineering.