The construction of the Polihali dam and Polihali transfer tunnel is set to start after the award of the two contracts by the Lesotho Highlands Development Authority (LHDA).

The award of the contracts, two of the Lesotho Highlands Water Project (LHWP) Phase II’s biggest to date, signals the start of the “final lap” of the water transfer infrastructure construction.

Work on the multibillion Maloti contracts starts in November and December respectively, with commissioning expected in 2028.

“This is an exciting moment for the project and the LHDA. With our experience in successfully delivering large and complex infrastructure projects, we are confident that we will deliver quality engineering showpieces even as we carefully manage impacts on people and the environment,” says LHDA CEO Tente Tente.

The SUN joint venture (JV) secured the M7.68-billion Polihali dam contract.

The JV's main partners include China’s Sinohydro Bureau 8 and Sinohydro Bureau 14, as well as South African firm Unik Civil Engineering and Lesotho firm Nthane Brothers.

Subcontractors include South African firms Melki Civils and Plant Hire and Mecsa Construction, along with Lesotho’s Sigma Construction and China’s Kunming Engineering.

The Matla a Metsi JV, which comprises South Africa’s GIBB and MPAMOT Africa; France-headquartered Tractebel Engineering SA/Coyne et Bellier and Lesotho-based LYMA Consulting Engineers, will supervise the construction.

The Polihali dam, a concrete-faced rockfill dam, similar to the Mohale dam, which was constructed in Phase I of the LHWP, will create a reservoir on the Senqu and Khubelu rivers with a surface area of 5 053 ha. The infrastructure also includes a spillway, a compensation outlet structure and a mini-hydropower station.

Meanwhile, the M9.2-billion Polihali transfer tunnel will be constructed by the Kopana Ke Matla JV, which comprises Chinese firms Yellow River Company and Sinohydro Bureau 3 and Unik Civil Engineering.

Subcontractors for this contract include Nthane Brothers, South Africa’s Esor Construction and Mecsa Construction.

Construction will be supervised by the Metsi a Senqu-Khubelu Consultants JV, which comprises Lesotho-based FM Associates and South African firms Zutari South Africa, Hatch Africa, Knight Piesold and SMEC South Africa.

The Polihali transfer tunnel will transfer water by gravity from the Polihali reservoir to the Katse reservoir, before being transferred through the delivery tunnel to the Muela hydropower station constructed in Phase I, and then on to the Ash River outfall outside Clarens, in the Free State, on its way to Gauteng.

The 38 km tunnel works also includes 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.

The LHDA will publish the notice of award, including other bidders and how they performed, for both contracts on its website.

The awards were announced shortly after the start of the procurement process for the design and construction supervision of the Oxbow Hydropower Scheme, also critical to Phase II, with March 2023 as deadline for the submission of bids for engineering, environmental and social consultants.