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Lesotho Highlands Water Project – Phase II, Lesotho and South Africa

2nd October 2015

By: Sheila Barradas

Creamer Media Research Coordinator & Senior Deputy Editor

  

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Name and Location
Lesotho Highlands Water Project (LHWP) – Phase II, Lesotho and South Africa.

Client
The Lesotho Highlands Development Authority (LHDA) and the Trans-Caledon Tunnel Authority (TCTA) are the implementing authorities.

The Lesotho Highlands Water Commission has an oversight function, advises the two governments and monitors the activities of the LHDA and TCTA.

Project Description
Phase I of the LHWP was officially completed in 2004.

Phase II of the LHWP will be implemented in terms of two distinct components: a water delivery system to augment the delivery of water to South Africa and a hydropower generation system.

Polihali dam
The Polihali dam will be built downstream of the confluence of the Senqu and Khubelu rivers and will be a 163.5-m-high concrete-faced rockfill embankment dam wall.

The crest length will be 915 m, with a full supply level of 2 075 m above sea level. A 49.5-m-high saddle dam and a side channel spillway will also be built.

Polihali to Katse tunnel
The 38.2-km-long, 5-m-diameter Polihali-to-Katse dam tunnel will be constructed to transfer water from the Polihali reservoir to the Katse reservoir.

Water will be abstracted from the Polihali reservoir through two separate concrete bell-mouth intakes on the western side of the Polihali reservoir, in the Khubelu river, 3 km upstream of the confluence with the Senqu.

Water will be transferred through the lower and upper intake tunnels to the intake gate shaft. Both tunnels will be constructed using drill-and-blast methods and will be fully concrete-lined. Hydraulic control will be effected by the valves in the intake structures.
The Polihali intake gate shaft will be used only for maintenance and water-quality control functions.

Advance infrastructure
Where possible, the existing infrastructure constructed in Phase I will be used. This includes access roads, power supply, telecommunication systems and camps.

Significant additional works contracts will be awarded for the construction of all-weather access roads, a bulk power supply network, telecommunications systems and project housing, as well as labour camps on both ends of the transfer tunnel.

A permanent housing development will be established near the Polihali dam and transfer tunnel, which will consist of project offices, and residential and community facilities.

This will require extensive infrastructure development before the mobilisation of contractors for the two main works contracts of the Polihali dam and transfer tunnel.

The Polihali intake site will use the infrastructure required to construct the Polihali dam and the transfer tunnel. This includes feeder roads and bridges around the reservoir to connect affected communities, power supply systems, construction camps and communications.

The facilities at Katse dam will be used for the Polihali-to-Katse tunnel construction. Existing facilities will be used to house consultants and construction management teams. Improvements to the water and sewage treatment plants, clinic and lodge will be undertaken.

Other infrastructure
In addition to the main access roads to service the construction phase, other access and feeder roads will be constructed around the reservoir to connect affected communities using pedestrian and light-vehicle bridges, while a pair of major road bridges will be built over the Polihali reservoir at Tlhakola, crossing the Khubelu river, and, near Mokhotlong, crossing the Senqu river.

Environmental measures
Environmental mitigation measures, including environmental flow matters and baseline studies, will be implemented.

The full extent is being studied in detail for implementation.

An environmental and social management programme is being implemented to address potential environmental and social impacts associated with Phase II activities.

The programme comprises baseline studies, including those pertaining to environmental flow requirements, biological and archaeological (including heritage) studies, socioeconomic and public health studies.

The programme also includes environmental- and social-impact assessments (ESIAs), and the implementation of the subsequent environmental and social management and action plans.

Social development programmes
These programmes, mitigation measures, resettlement requirements and baseline studies, as well as public relations and awareness campaigns, will be implemented.

The full extent of these measures are being studied and discussed.

Infrastructure developments might include medical clinics, feeder roads and bridges around the reservoir to connect affected communities, and social development projects such as schools, churches and community halls.

The above will be informed by the outcome of the baseline studies as well as the sustainable development programmes to be designed.

Pumped-storage scheme
Phase II might also include a pumped-storage scheme, associated transmission lines and works using the existing Katse reservoir as the lower reservoir, and a new upper reservoir in the Kobong Valley.

The exact form of the hydropower component is still to be agreed by the governments of South Africa and Lesotho.

The decision will be informed by further feasibility studies.
A request for proposals (RFP) has been issued for the additional studies required.

Value
The project is expected to cost R17.5-billion at completion.

Duration
Water delivery is expected to begin in 2024, based on the current project programme.

Latest Developments
Phase II is still in the early stages and the focus in 2015/16 will be largely on the procurement of consultants and contractors for the advance infrastructure works and the main works of the water transfer component of the project. The advance infrastructure includes roads, bridges, telecommunications, geotechnical investigations and project housing.

The LHDA has awarded the professional services contract for the planning, design and construction supervision of the housing and associated infrastructure for Phase II of the LHWP to Polihali Infrastructure Consultants, a joint venture between Mott MacDonald PDNA and Khatleli Tomane Moteane.

Work on this R74.3-million contract started in early September and should be completed in the latter part of 2021.

This contract forms part of the advance infrastructure works that must be completed to facilitate the construction of the main works for the Polihali dam and transfer tunnel and the hydropower station.

This contract includes the preparation of preliminary and detailed architectural and engineering designs of the temporary and permanent project housing and related infrastructure, and preliminary and detailed design of utilities; preparation of tenders and contract documents; the procurement of construction contracts; the supervision of the construction programme and environmental monitoring during construction.
The project housing works comprise accommodation facilities for the staff and workforce, site offices, workshops, plant yards and other work areas. Some of the structures built as part of this contract are intended for long-term use.

These include staff accommodation in the Polihali reservoir area, which will be built as a village with the appropriate associated facilities; a visitors lodge at the staff village, which will become a tourist facility and the employer’s and engineer’s offices at the dam site, which will become the operations staff offices and a visitors centre on completion of the scheme.

Other cntracts that have been awarded on which work has started include:
• The reservoir demarcation contract has been awarded to the Lesotho-based Maleka, Ntshihlele, Putsoa Joint Venture (JV).
The contract comprises surveying and building beacons around the estimated 250 km perimeter of the Polihali reservoir at a level 5 m higher than the full supply level to allow for a safe margin above the full supply level.
Demarcation of the reservoir is critical for the acquisition of land and the resettlement and compensation of people in the catchment area whose homes and livelihoods will be affected by the construction of the dam.
It is also essential for the planning of Phase II activities.
• Jeffares & Green, in association with GWC Consulting Engineers, has been contracted as the geotechnical engineers. Geotechnical investigations involve the extraction of rock and soil for testing purposes to provide comprehensive data for the dam and tunnel design consultants.

The investigations will also identify the suitability, quality and quantity of the construction material at all the investigated quarries.
• The consulting contract for the Polihali north-east access road has been awarded to the SMEC-FMA JV, which is a JV between the Bloemfontein office of international engineering consultancy SMEC and Lesotho-based civil and structural engineer FM Associates.
This contract involves upgrading the existing road to a standard that allows for the safe movement of construction vehicles during the mobilisation of machinery and facilities for other advanced-infrastructure contractors who will require unhindered access to the Polihali dam site.
Contracts that are in negotiation and that are close to being awarded include:
• the drilling contract for the geotechnical investigations for the Polihali dam and transfer tunnel.
Contracts being evaluated by the LHDA include:
• the Polihali western access road, which entails designing and supervising the construction of the road that also forms part of the advance infrastructure works; and
• the Polihali dam diversion tunnel, which entails designing and supervising the construction of the diversion tunnels that will divert water in the river away from the construction site so that dam construction can take place.

Contracts currently out to tender include professional services for:
• the ESIAs for housing, the Polihali dam and reservoir, the eastern transfer tunnel and the western (Katse) site facilities;
• resettlement planning and implementation for the western site facilities; and
• designing and supervising construction of the bulk power supply and telecommunications.

Key Contracts and Suppliers
Maleka, Ntshihlele, Putsoa JV (reservoir demarcation); Jeffares & Green, in association with GWC Consulting Engineers (geotechnical engineers); SMEC-FMA JV (Polihali north-east access road – consultant) and Polihali Infrastructure Consultants, a joint venture between Mott MacDonald PDNA and Khatleli Tomane Moteane (planning, design and construction supervision of the housing and associated infrastructure – Phase II).

On Budget and on Time?
Water delivery is expected to begin in 2024 based on the current project programme.

It is too early to comment on the hydropower component, given that it is under feasibility and its exact form is still to be determined.

Contact Details for Project Information
LHDA responsible manager – divisional manager Phase II Tente Tente, tel +266 222 46000 or email tentet@lhda.org.ls.
LHDA public relations manager Masilo Phakoe, tel +266 2224 6000 or email phakoem@lhda.org.ls.

Edited by Martin Zhuwakinyu
Creamer Media Senior Deputy Editor

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