The long-delayed Lesotho Highlands Water Project (LHWP) Phase II has progressed steadily to 56.7% completion, with R24-billion of the R53-billion allocated to the project having been spent.

Construction of the 165-m-high concrete- faced rockfill Polihali dam has moved steadily to 53% completion, after an initial delayed start, while the 2 322-million-cubic-metre Polihali reservoir is expected to start impounding in July 2027.

Meanwhile, construction of the 38 km water transfer tunnel has reached the 58% completion mark. However, tunnel excavations experienced a slight slippage owing to poor geological conditions underground, leading to the slow progress of the tunnel boring machines (TBM) on both the Polihali and Katse sides.

The Polihali TBM has excavated about 10.5% of the waterway tunnel, while the Katse TBM has excavated 14.3%. A mitigation plan has been put in place to recover the lost time.

Another major milestone is the 100% completion of the LHWP Phase II’s three major bridges: Senqu (90 m high), Khubelu (25 m high) and Mabunyaneng (12 m high).

The Lesotho Highlands Development Authority (LHDA) officially opened the Khubelu and Mabunyaneng bridges in Mokhotlong on September 11, following the completion of the Senqu bridge in February.

The three bridges, designed to accommodate two-way vehicular traffic and pedestrians, will provide safe, reliable and uninterrupted access to the national road network through the A1, the main route linking the Mokhotlong district with Maseru, ensuring year-round connectivity, even when the Polihali reservoir reaches full supply.

The Khubelu bridge, the second largest of the three bridges, features a 270-m-long curved deck comprising nine 30 m spans, supported by eight piers and two abutments. About 25 m above the valley floor, the structure required 63 precast beams, each weighing 52 t.

The Mabunyaneng bridge spans 120 m across the valley, with four 30 m spans supported by three piers and 28 precast beams, standing about 12 m above the valley floor. Its spans required 28 precast beams, each weighing 52 t.

Both bridges are 13.55 m wide, with an 8 m carriageway flanked by 2 m walkways on either side.

The works also included realigning a 2 km section of the A1 and constructing retaining walls, stormwater drainage and road safety infrastructure.

The single greatest risk during construction was transporting the 52 t beams to site and placing them using two 60 t cranes.

The Khubelu and Mabunyaneng bridges sit within 500 m of each other at the confluence of the Mabunyaneng and Khubelu rivers, and about 22 km before the Senqu bridge, which is 15 km from Mokhotlong.

At peak construction, the project employed 327 site workers, comprising 94 local general workers and 218 semiskilled Lesotho nationals, together with 29 semiskilled South African workers, supported by 45 permanent staff.

The project created 66 permanent positions in total, and women held 32% of roles across engineering, safety, quality control and laboratory management.

The project invested R5.3-million in training and development, delivering 515 training sessions that reached 140 site workers, 24 staff members and 37 local enterprises.

Twenty-nine unskilled workers progressed into semi-skilled technical roles, and 12 graduate engineers received experiential training and mentorship. The project spent a further R218.2-million with Lesotho-based suppliers and subcontractors.

The South African Institution of Civil Engineering (SAICE) named the Mabunyaneng and Khubelu bridges project as a finalist in the Technical Excellence, International Project of the Year category in the 2026 SAICE National Awards.

Zutari, formerly Aurecon Lesotho, supported by subcontractors Lesotho’s White Life Consultants and South Africa’s Leporogo Specialist Engineers, designed the bridges and supervised their construction.

The construction contractor was the Concor-Nthane Brothers M&K Bridges joint venture, which comprised main partners South Africa’s Concor Construction and Lesotho’s Nthane Brothers, along with subcontractors South Africa-based Post Tensioning and Structural Solutions and Lesotho-based Bridge Joints and Rehabilitation Contractors.

The project’s update followed a three-day site visit last month by South African Water and Sanitation Minister Pemmy Majodina and Planning, Monitoring and Evaluation Deputy Minister in the Presidency Seiso Mohai to assess the progress of the major construction works of the Polihali dam and the Polihali-Katse water transfer tunnel and other associated infrastructure such as road networks and the resettlement programme of affected communities.

The LHWP Phase II is being implemented by the LHDA with South Africa’s Trans-Caledon Tunnel Authority (TCTA) as the financier, both under the Lesotho Highlands Water Commission (LHWC), which represents the two countries.