In the highlands of Mokhotlong, Lesotho, the Khubelu and Mabunyaneng bridge projects are rising not only through shrewd engineering, but because of critical collaboration between Lesotho and South Africa that will ensure sustainable water supply to parts of Johannesburg and much of the Gauteng province. 

These two bridges form part of the ongoing work under the Polihali Dam, which is Phase II of the Lesotho Highlands Water Project (LHWP) and will link to the Katse Dam, completed in Phase I.

Despite a five-month project start delay (only starting March 2024) and various logistical challenges - leading formwork and scaffolding provider, Uni-span has ensured that the new bridges have sufficient infrastructure support and will be delivered on budget and on time by October 2025.

Spearheaded by the Concor-Nthane Brothers Joint Venture, these bridges are more than infrastructure; they’re symbols of cross-border cooperation in the Lesotho-South Africa partnership, economic upliftment, and regional resilience.

“Every bit of progress made in improving access to water is crucial in addressing the water crisis affecting South Africa and the SADC region as a whole,” says Benno Jacobs, General Manager at BUD Rental Services, Uni-span’s holding company. “Alleviating bottle necks in water security will enable all industries – including but not limited to farming, energy and manufacturing – to plan their operations for better long-term growth, as fresh water is the one resource that cuts across all areas of society.

“Lesotho, aptly known as The Kingdom of the Sky, is one of the most elevated countries in the world, making it an ideal source of consistent and fresh water,” he says.

With a promise to confidently deliver safe, efficient and reliable formwork and scaffolding solutions across Africa, Uni-span’s role in the LHWP demanded careful logistical and technical planning.

Due to the altitude and the very mountainous region, engineering teams need to plan with precision, not only to deliver the right formwork for a complex construction project but also to bring additional materials and supplies, given the remoteness of the site. 

“We had to make sure we brought everything we needed, extra screws, tools, plus spares, because the nearest hardware store was hundreds of kilometres away in South Africa,” says Jacobs. “The narrow mountain passes also meant that if another vehicle got stuck on the road, for whatever reason, our vehicles could be delayed for hours, or days even, making the need for meticulous planning that much more important to bring our client’s vision to life, no matter the challenge.”

The Khubelu River and Mabunyaneng River bridges run along the A1 Road, Lesotho’s main road connecting Maseru, the nation’s capital, in the west to Mokhotlong in the east. 

Their upgrades will ensure that when the Polihali Dam wall is fully sealed, the road isn’t submerged, and traffic continues to run smoothly.

The new Khubelu River bridge will be 20metres high at its highest point (from 6m) and the Mabunyaneng River bridge will be 10m high. These rivers are part of the same water system and are linked to the Vaal River in Gauteng, South Africa. 

Uni-span is also providing construction support infrastructure for the new intake tunnel linking the Polihali Dam to the Katse Dam, which already supplies Gauteng. Tunnelling through the Maluti Mountains is already underway, with completion expected between late 2026 and early 2027.

The LHWP has become an integral part of securing Lesotho’s economic future, providing jobs in the project itself but also over the long term, in terms of maintenance and service provision. 

Uni-span’s massive ongoing construction infrastructure support included a complete scaffolding solution for large scale civil works and strong, versatile timber support for complex civil applications, and particularly in mountainous water exposed environment.

The designs had to ensure safe, efficient and reliable support, so the bridges could be built on time, on budget and robustly, despite logistical issues.

“Once the Polihali Dam is finally sealed and filled, the existing bridges will be totally submerged, as well as a few low-lying homesteads along the river valley floor,” says Jacobs. 

“There is no room for error when it comes to bridge design, but more importantly, when it comes to the integrity that tailored formwork provides for robust structural performance.”