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Lesotho Highlands Water Project – Phase 2, Lesotho to South Africa

27th June 2014

  

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Name and Location
Lesotho Highlands Water Project (LHWP) – Phase 2, Lesotho to South Africa.

Client
The governments of South Africa and Lesotho. The Lesotho Highlands Water Commission, Lesotho Highlands Development Authority and the Trans-Caledon Tunnel Authority (TCTA) are the countries’ respective implementing authorities.

Project Description
Phase 1 of the LHWP was officially completed in 2004.

Phase 2 of the LHWP will be implemented in terms of two distinct systems – 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 Katse dam. The tunnel is sized to convey a peak power generation flow of 35 m3/s. 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, three kilometres 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 1 will be used. This includes access roads, power supply, telecommunication systems and camps.

The Polihali intake site will utilise the infrastructure required to construct the Polihali dam and the 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. Housing for the consultants and construction management teams will be provided using existing facilities. Improvements to the water and sewage treatment plants, clinic and lodge will be undertaken. A primary school will be built.

The existing camp for construction workers at Mphorosane will be refurbished for use by the Polihali to Katse tunnel contractors. Improvements and expansions to the existing water and sewage treatment plants will be required. Other ancillary services will be constructed as determined during the design phase.  A satellite police station and accommodation facilities will be built and manned by Lesotho.

The upgrading of the existing hospital facilities at the Mamahau mission will be investigated and implemented to serve as a jointly managed project hospital, if deemed feasible.

Other infrastructure
Other access and feeder roads, management and labour camps, as well as telecommunication and construction power systems, will be built in addition to those detailed.

Where possible, the existing infrastructure constructed in Phase 1 will be used. This includes access roads, power supply, telecommunication systems and camps.

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.

Social development programmes
Social development 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. Their implementation will soon be agreed to by the parties to impose the absolute minimum disruption to the affected households and communities.

These infrastructure developments may 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.

Pumped-storage scheme
Phase 2 may also include a pumped-storage scheme and associated transmission lines and works by utilising the existing Katse reservoir as the lower reservoir and a new upper reservoir in the Kobong Valley. The implementation of the scheme is subject to a joint decision by the two governments, which are still being debated.

Value
The project is estimated at R17.5-billion.

Duration
Phase 2 of the LHWP is expected to start supplying South Africa with water by 2023.

Latest Developments
The Lesotho Highlands Development Authority says it expects Phase 2 of the LHWP to be completed by mid-2023.

Phase 2 executive manager Mark Matchett says the authority is about to start a procurement process, which will run for six  to nine months. During this time, the authority hopes to have procured most of the design contracts. Towards the middle to the end of next year, it hopes to be in a position to start procuring contracts for the construction works.

The dam and tunnel designs are envisaged to start during the first or second quarter of 2015, while construction is expected to start during the third or fourth quarter.

Matchett says they can get to the minimum operating level by 2022, if there is sufficient rain.

The environmental studies, mitigation plans, resettlements and compensations are under way and are expected to be completed by the end of October or November.

About 2 500 workers are expected in the area at the height of the project. A township will be established and an existing lodge will be developed to meet the accommodation demand.

Divisional manager of the Phase 2 project Tente Tente says an anticorruption policy is in place to ensure there will be no underhanded tactics throughout the tendering process.

He also says that no monopolies will be tolerated and that companies need to give special consideration to partnering with other companies that do not fall under their stables, as bids from the same entities will not be considered.

On Budget and on Time?
Too early to state.

Key Contracts and Suppliers
C4/Seed joint venture (feasibility study), the TCTA (debt management and funding of the water-transfer portion of the project, as well as the operation and maintenance of the delivery tunnel north), Mops Civil (access road) and BKS (construction of measuring weir).

Contact Details for Project Information
Lesotho Highlands Water Commission, Leon Tromp, tel +266 5221 4035 or email leon@lhwc.org.ls.
TCTA, tel +27 12 683 1200, fax +27 12 683 1361 or email info@tcta.co.za.

Edited by Creamer Media Reporter

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