Tunnelling by the Katse TBM was launched on 15th January 2025 on the Lesotho Highlands Water Project II by the Minister of Home Affairs Honourable Lebona Lephema on behalf of the Right Honourable the Prime Minister of Lesotho at a ceremony held on site at Ha Bereng, Leribe. This marks the first tunnel boring by a TBM to take place in the highlands of Lesotho since tunnel construction under Phase I over 20 years ago.
Honourable Lephema was joined by their excellencies the High Commissioner of South Africa to Lesotho and the ambassador of China to Lesotho, the honourable Minister of Natural Resources and other cabinet Ministers, members of the Lesotho Highlands Water Commission, the LHDA Board of Directors and the LHDA executive. Representatives of the partner firms that are overseeing the construction of the Polihali Transfer tunnel, other dignitaries and representatives of Project affected communities were also present at this momentous occasion.
This is the first of two 5.38m diameter double-shield TBMs designed to excavate the 38km, 5m i.d. Polihali Transfer Tunnel from the Leribe side.
In keeping with the tradition of naming TBMs before they start boring, the Prime Minister named the TBM Khoiti ea ‘Ngoaha Kholo2 (the rat mole of 200 years).
“This milestone reflects the dedication and commitment of the government of Lesotho, the LHWC, the LHDA, and all consultants and contractors involved. I am confident that with the continued partnership and support of the government of the Republic of South Africa, we will achieve great things for both our nations,” said Rt Hon Matekane.
Khoiti ea Ngoaha Kholo2 TBM will bore approximately 20m per day and will install a segmental tunnel lining. The second TBM that will dig the tunnel from the Polihali side is expected to arrive on site in the middle of 2025. The TBMs were manufactured by CCCC Tianhe of China specifically for the excavation of the Polihali to Katse Transfer Tunnel and were designed by Robbins.
The Polihali Transfer Tunnel works also include the intake works and gate shaft at the Polihali reservoir; outlet works and gate shaft at the existing Katse reservoir, with underwater connection to the lake; access adits to the waterway and associated construction infrastructure.
Milestones achieved under this component in 2024 include the successful breakthrough of the upper intake tunnel into the lower intake tunnel on 19 August, after seven months of tunnelling, and the commencement of Polihali’s gate shaft excavation using the raise boring method on 26 August.
The Polihali to Katse Transfer Tunnel is a key component of Phase II of the Lesotho Highlands Water Project. It will facilitate the gravity transfer of water from the Polihali reservoir to the Katse reservoir enabling the transfer of 1 270 cubic meters of water, contributing towards meeting SA’s Gauteng increasing water needs.
The tunnel is excavated using both tunnel boring and drill-and-blast methods on both the Leribe and Polihali ends. It was designed by MSKC JV, a consultancy firm supervising construction of the tunnel, while the M9bn construction contract was awarded to Kopano Ke Matla Joint Venture, comprising Yellow River Company, Sinohydro Bureau 3, and Unik Civil Engineering.
The advancements on the transfer tunnel and other Project components, according to the Chief Executive of the LHDA, Tente Tente indicate the commitment of the teams on the ground to implement the project, in line with the desires of the Project owners. He explained that building on these milestones, Phase II continues to maximise economic benefits for the nations of the two countries; creating more than 11,000 jobs to date, injecting over M366 million in contracts among small to medium sized Basotho businesses, as well as implementing livelihoods and environmental programmes that are developing skills, introducing diversified livelihoods options and rehabilitating the environment.
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