Lesotho Highlands Water Project tunnel to close for six-month maintenance,minimal impact expected on supply
The Lesotho Highlands Water Project (LHWP), an integral part of South Africa’s water supply network, is set to undergo its six-month maintenance closure.
This closure will allow critical work on the water transfer and delivery tunnels that supply water from Lesotho to South Africa.
The governments of South Africa and Lesotho will be working together on the maintenance which will include grit-blasting and re-applying corrosion protection on the steel-lined section of the tunnel.
The closure started on October 1.
This work is expected to extend the lifespan of the infrastructure by 20 to 30 years. The tunnel closure will affect both the Phase I Water Transfer and Delivery Tunnels, halting the flow of water from the Katse Dam to the Muela Hydropower Station, thereby ceasing power generation at Muela for the duration.
Similarly, the 37-kilometre delivery tunnel, which supplies water to South Africa, will be closed, leading to a temporary halt in cross-border water deliveries.
Despite the potential for concern, Water and Sanitation Minister Pemmy Majodina has assured that “comprehensive measures” have been put in place to manage water security during the closure.
Working with municipalities and water boards, the Department of Water and Sanitation has coordinated efforts to mitigate disruptions. A crucial component of these preparations is the Integrated Vaal River System (IVRS), which comprises 14 interconnected dams and is equipped to supply water during the maintenance period.
“The analysis confirmed that the impact of the tunnel closure on the overall IVRS will be minimal, as most dams in the IVRS will be relatively full at the time of closure,” the department said in a statement.
The Lesotho government has also prepared for the shutdown by securing additional electricity supply to ensure continuous power during the maintenance. While there will be no power generation from the Muela Hydropower Station during this time, these measures are expected to prevent power shortages in Lesotho.
Minister Majodina’s counterpart, Minister Mohlomi Moleko of Lesotho, echoed her sentiments, highlighting the need for this short-term inconvenience to prevent long-term infrastructure degradation. Both countries have committed to ensuring that the tunnel maintenance stays within the scheduled six-month period.
Water security remains a significant issue for South Africa, and the LHWP plays a key role in meeting the country’s needs. Proactive measures taken ahead of the closure, including receiving a substantial portion of the year’s water deliveries before the shutdown, should alleviate concerns about potential water shortages.
Furthermore, South Africa’s analysis of the IVRS system has indicated minimal risk to water availability, with dams like Vaal and Sterkfontein prepared to augment supply if necessary.
The LHWP tunnel closure will be closely monitored, with all necessary technical resources mobilised to ensure the work proceeds efficiently.
The Lesotho Highlands Water Project (LHWP) is a multi-phased project to provide water to the Gauteng region of South Africa and to generate hydro-electricity for Lesotho. It was established by the 1986 Treaty signed by the governments of the Kingdom of Lesotho and the Republic of South Africa.
The project entails harnessing the waters of the Senqu/Orange River in the Lesotho highlands through the construction of a series of dams for the mutual benefit of the two countries. Phase I of the project was completed in 2003 and inaugurated in 2004.
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