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South Africa and Lesotho all set for the closure of Lesotho Highlands Water Project tunnel

  • South Africa and Lesotho all set for the closure of Lesotho Highlands Water Project tunnel
    Lesotho Highlands Water Project (LHWP).
    Credit: Lesotho Highlands Development Authority.
  • 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.

About the entity

Department of Water and Sanitation, South Africa
The Department of Water and Sanitation is the custodian of South Africa's water resources.

Water and Sanitation Minister, Pemmy Majodina and her counterpart from the Kingdom of Lesotho, Minister Mohlomi Moleko, have expressed optimism on the state of readiness of the two countries to carry out the six-month maintenance of the closure of the Lesotho Highlands Water Project (LHWP) tunnel

The two ministers held a virtual meeting on Thursday, 26 September 2024 with a view to assess the state of readiness ahead of the tunnel closure from 01 October 2024 to 31 March 2025, which is aimed at undertaking maintenance work on the transfer and delivery tunnels of the LHWP. The planned maintenance forms part of the ongoing commitment by the two governments to ensure long-term sustainability and integrity of the infrastructure of the LHWP. 

The closure of the LHWP tunnel will affect the Phase I Water Transfer and Delivery Tunnels; this will result in the total shutdown of the water delivery system for six months

During the discussions between the two Ministers, there was a palpable agreement that the maintenance work should be carried out effectively and within the scheduled six-month period. 

The work required to be undertaken during the closure of the tunnel period includes grit-blasting the steel-lined section around the entire circumference and re-applying corrosion protection on the tunnel lining, as well as other maintenance and repair work identified during the 2019 maintenance shutdown. This work is expected to protect the infrastructure for another 20-30 years.

Meanwhile, the closure of the LHWP tunnel will affect the Phase I Water Transfer and Delivery Tunnels. This will result in the total shutdown of the water delivery system for six months

During this time, there will be no transfer of water from the Katse Dam to Muela Hydropower Station (Transfer Tunnel – 45km), which will result in the stoppage of power generation at the Muela Hydropower Station in Lesotho. Additionally, there will be no delivery of water from Lesotho to South Africa through the 37 km delivery tunnel. (Delivery Tunnel South 15km and Delivery Tunnel North 22km).

To mitigate against the impact of the tunnel closure on water availability in the affected areas in South Africa, the IVRS, which consists of fourteen interconnected dams, has enough water for the duration of the maintenance period

Despite the impact on water transfer, both Ministers have assured that during the six-month maintenance period, citizens should not be alarmed as there have been comprehensive measures taken by the Department of Water and Sanitation, working collaboratively with municipalities and water boards to ensure water security through water transfer within the Integrated Vaal River System (IVRS).  

Both Ministers acknowledged that although the tunnel closure will be a short-term inconvenience, it is crucial to undertake it in order to prevent long-term inconveniences in the future.  

In preparation for this planned closure, both governments took proactive measures to ensure that the maintenance would be conducted smoothly, with minimal disruption and to the benefits that accrue to Basotho and South Africans from the LHWP. 

The contracted water transfer from the two dams in Lesotho is 780 million cubic meters per annum. During the current year, approximately 700 million cubic meters of water have been transferred in anticipation of the closure. There will thus be a shortfall on the annual water transfer from the LHWP of approximately 80 million cubic meters which will be made up after the completion of the tunnel maintenance.

Lesotho Highlands Water Project (LHWP). Image: Lesotho Highlands Development Authority.

This proactive measure has allowed South Africa to receive most of its annual water deliveries, ensuring that both the water supply and the royalties revenue that Lesotho receives from those deliveries are minimally impacted. The Lesotho Government has also put in place concrete plans to secure additional electricity supply in the region, to ensure that reliable supply of electricity continues in Lesotho during this period. 

To mitigate against the impact of the tunnel closure on water availability in the affected areas in South Africa, the IVRS, which consists of fourteen interconnected dams, including the Vaal, Sterkfontein, Grootdraai and Bloemhof Dams, which is augmented by the Katse and Mohale Dams in Lesotho, has enough water for the duration of the maintenance period.  

The dams are linked to each other by a system of rivers, canals, tunnels, pipelines, and pump stations. The Department of Water and Sanitation manages the IVRS as a system, in which water can be transferred from one part of the system to another, as and when required. 

The Government of South Africa has undertaken a thorough analysis to assess the risk to the performance of the IVRS because of the tunnel closure and to determine the impact of the tunnel closure on water availability to users. 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.

As the maintenance is set to get underway, both Ministers have called on communities in both South Africa and Lesotho to cooperate during the period by taking responsible actions

Furthermore, comprehensive technical and operational plans have been put in place to ensure minimal disruption to the everyday lives of the people in both countries. All resources for the implementation of the maintenance work have been mobilised, and preparations ready for the work ahead. 

Procurement processes to acquire professional services have been completed by both implementing agencies in the respective countries, the Trans Caledon Tunnel Authority (TCTA), an entity of the Department of Water and Sanitation, and the Lesotho Highlands Development Agency (LHDA) in Lesotho. The contractors that will provide maintenance service in both countries are already on site and equipment has been delivered to sites in both countries.   

Both countries take pride in ensuring that no one is left behind in the beneficiation and participation in opportunities that arise from all works within the project. The contractors, sub-contractors and employees who will work on the contract are from South Africa, Lesotho and the Southern Africa Development (SADC) region. This is another expression of the commitment of both countries to ensure regional cooperation and equitable sharing of the benefits that accrue from the project and resources in the region.

As the maintenance is set to get underway, both Ministers have called on communities in both South Africa and Lesotho to cooperate during the period by taking responsible actions that will help reduce the impact of this temporary closure of the tunnel. 

Minister Majodina has urged citizens in South Africa to intensify water conservation measures in their spaces. 

“Given the temporary halt in water deliveries, it is essential to use water sparingly and avoid wastage during this time. Despite preparations already made by the government to ensure continued supply of water, it is crucial that we collectively minimise the impact on all of us through responsible consumption of water during this time,” she said. 

Meanwhile in Lesotho, the Muela Hydropower Stations supplies close to 50% of the overall electricity demand in the country. In the absence of hydropower generation, Minister Moleko has appealed to Lesotho citizens to use electricity responsibly, to be conscious of their usage and minimise consumption and the impact on the grid. 

“Energy conservation will be key to ensuring stable power supply during this period. This is as Lesotho will have to import increased amounts of electricity from the region, to make up for the shortfall during Muela’s outage,” emphasised Minister Moleko. 

Both Governments have put in place mechanisms to mitigate the impact of these temporary disruptions and are confident that with the cooperation of the public, the effects will be kept to a minimum.

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