The Lesotho Highlands Development Authority (LHDA) has entered an important milestone in the procurement of Phase II major works construction contracts, with the advertisement of the tender for the construction of the Polihali Transfer Tunnel issued on 21 May 2021. The tender for the Polihali Dam construction will follow shortly.
The Polihali Transfer Tunnel will be 38km long with a 5m nominal bore. It will transfer water by gravity from Polihali to the Katse reservoir. Tunnel boring and drill and blast methods will be used to excavate the tunnel.
“Our objective is to attract firms with experience in the construction of major underground works under complex geological and geotechnical conditions, diverse environmental conditions, in remote areas and at high altitude. Equally important is to attract firms that have impeccable records in delivering projects of this magnitude within budget and the set timeframes,” confirmed Tente Tente, CE of the LHDA.
Interested construction firms have up to 30 August 2021, to submit tenders. Specific information on the requirements and conditions of the tender is available on the LHDA website at http://www.lhda.org.ls/tenderbulletin/currentProcurement.aspx.
The Metsi a Senqu-Khubelu Consultants (MSKC) Joint Venture was awarded the contract for the design and construction supervision of the Polihali Transfer Tunnel and its secondary structures. MSKC comprises Lesotho-based FM Associates (Pty) Ltd, and South African firms Zutari (Pty) Ltd, Hatch Africa (Pry) Ltd, Knight Piesold (Pty) Ltd and SMEC South Africa (Pty) Ltd.
The tender for the construction procurement of the transfer tunnel is launched as construction activity on ten advance infrastructure contracts progresses steadily with some contracts expected to be completed in 2021, including the Polihali diversion tunnels. Cumulative excavation progress in both tunnels is in the order of 1,243 out of a total of 1,810m to date. Construction of the 33kV line, which will provide temporary power supply to the Polihali village, was completed in 2020. Work on the 132kV line has advanced with construction of; access roads, 91 tower foundations and erection of 84 towers out of a total of 93. The Polihali and Katse civil works; access roads, pipe laying for potable water and sewerage lines has been completed, and construction on the Phase II main access roads is progressing well.
According to the current master programme, water delivery is scheduled for 2027. Timeous construction of the dam and transfer tunnel is critical to meeting the water delivery deadline of the project.
Phase II of the Lesotho Highlands Water Project builds on the successful completion of Phase I in 2003. It delivers water to the Gauteng region of South Africa and utilises the water delivery system to generate hydro-electricity in Lesotho.
The Lesotho Highlands Water Project (LHWP) is multi-phased, multi-billion Maloti/Rand project between the Governments of the Kingdom of Lesotho and the Republic of South Africa.
It comprises water transfer and hydropower generation components with associated ancillary developments. The water transfer component entails the construction of dams and tunnels in Lesotho, enhancing the use of water from the Senqu (Orange) River and its tributaries by storing, regulating, diverting and controlling the flow to effect the delivery of specified quantities of water to South Africa, and utilizing the delivery system to generate hydro-electric power in Lesotho.
The major works of Phase I included the construction of the Katse Dam, the transfer and delivery tunnels, Matsoku Weir, ‘Muela Hydropower Plant and the Mohale Dam. The Phase II water transfer component comprises a dam at Polihali and a gravity tunnel that will connect the reservoir at Polihali with the Katse reservoir. The further feasibility studies for the hydropower component of Phase II have concluded that conventional hydropower is the more feasible option to meet Lesotho’s energy needs. Three potential sites were identified: two on the Senqu River and a third site at Oxbow on the Malibamats’o River. The plan is to commission the selected option at the same time as Water Transfer component, which is 2027.
The Lesotho Highlands Development Authority (LHDA) is the implementing and management authority of the Lesotho Highlands Water Project, on behalf of the government of Lesotho.