Bridge Contract Awarded on Lesotho Highlands Water Project
Lesotho-South African joint venture wins US$26.7 million contract.
The Lesotho Highlands Development Authority (LHDA) has completed the construction procurement for the remaining two major bridges to be built under phase two of Lesotho Highlands Water Project (LHWP), awarding a M511.5 million (US$26.7 million) contract to the Concor-Nthane Brothers M&K Bridges Joint Venture in late August.
Work on the contract commenced on 29 August and the two bridges across the Mabunyaneng and Khubelu rivers are expected to be completed by the end of October 2025.
The joint venture comprises main partners Concor Construction (South Africa) and Nthane Brothers (Lesotho) and subcontractors Post Tensioning and Structural Solutions (South Africa) and Bridge Joints and Rehabilitation Contractors (Lesotho).
The M2 billion (US$104.4 million) contract for Senqu Bridge, the largest of the phase two bridges, was awarded in late 2022 to the WRES Senqu Bridge Joint Venture. The primary partners are Webuild (Italy), Raubex Construction (South Africa), Enza Construction (South Africa) and Sigma Construction (Lesotho).
Subcontractors include EXR Construction (South Africa), Gleitbau-Geselschaft (Austria), Post Tensioning and Structural Solutions (South Africa), and Freyssinet International et Cie (France).
The three bridges will provide access to Mokhotlong town across the Polihali reservoir even at full supply and will maintain connectivity to the national road network along the A1, the main road between the Mokhotlong district in the mountainous north-east of the Lesotho and the capital, Maseru.
“The impounding of the Polihali reservoir will submerge existing roads and tracks, affecting communities in the valleys and tributary catchments of the Senqu, Khubelu, Mokhotlong, Moremoholo and Sehonghong rivers," said Gerard Mokone, manager of the LHDA’s Polihali branch. "The major bridges along with a network of feeder roads and the main access roads to the project area all contribute towards minimising this disruption and help to restore community access to healthcare facilities, schools, shops and markets.”
For the Senqu Bridge project, construction of the temporary site facilities is well advanced and excavations have started for the pier and abutment foundations necessary to support the 825m-long and 90m-high bridge.
The Khubelu Bridge will be approximately 270m long with nine 30m spans and two abutments. The Mabunyaneng Bridge, the smallest of the three bridges will be approximately 120m in length and has four 30m spans and two abutments. The bridges will both be 13.55m wide.
“The trio of bridges will not only form part of the safe and efficient road infrastructure network constructed under Phase II but will be a major tourist attraction contributing to long term benefits in stimulating sustainable economic growth,” Ntsoli Maiketso, the phase II divisional manager, stated.
Work on the design of the Mabunyaneng and Khubelu bridges started in 2018, led by Zutari, formerly Aurecon Lesotho. Zutari also designed the Senqu Bridge and is supervising the construction of the three bridges.
Phase two of the LHWP entails the construction of the Polihali dam, the 38km Polihali transfer tunnel, the associated infrastructure and a hydropower plant at Oxbow. It builds on the successful completion of phase one in 2003.
The LHWP delivers water to the Gauteng region of South Africa and utilises the water delivery system to generate hydroelectricity for Lesotho. Phase two will increase the current supply of 780 million cubic metres a year to more than 1 270 million cubic metres a year. It will also increase the amount of electricity generated in Lesotho.
Last month, the New Development Bank agreed to provide ZAR3.2 billion (US$171.5 million) to support the implementation of phase 2.
Also in August, an early construction milestone on the Polihali dam was achieved with the diversion of the Senqu River by the pre-cofferdam, and the subsequent diversion of the river into and through the diversion tunnels ahead of the construction of the cofferdam upstream of the Polihali dam wall.
The M7.68 billion (US$401.4 million) construction contract for the Polihali dam was awarded in November 2022 to the SUN Joint Venture. The main partners are China's Sinohydro Bureau 8 and Sinohydro Bureau 14. Subcontractors include Melki Civils and Plant Hire (South Africa), MECSA Construction (South Africa), SIGMA Construction (Lesotho) and Kunming Engineering (China).
Photo: Senqu Bridge construction site (Source: LHDA)