Maintenance work on the Lesotho Highlands Water Project (LHWP) water transfer and delivery tunnels has been completed and the tunnels are being refilled.
The Department of Water and Sanitation says water from Lesotho arrived at the Little Caledon tunnel on Wednesday and was expected to arrive at the Ash River Outfall Works in Clarens, Free State, yesterday.
The LHWP tunnel system was shut down on October 1 last year for a six-month joint maintenance operation.
The project involved work undertaken by the Trans-Caledon Tunnel Authority (TCTA) on the Delivery Tunnel North in South Africa, and the Lesotho Highlands Development Authority (LHDA) on the Transfer and Delivery South Tunnels in Lesotho.
The tunnel was scheduled to reopen in March this year, but because of maintenance work delays experienced in the Delivery Tunnel South on the side of Lesotho, the closure was extended.
Maintenance work on the South African side was completed on schedule and finalised on March 19.
“The filling of the tunnel started with the filling of Muela Dam in Lesotho between 13-17 May 2025, and the Department of Water and Sanitation and the TCTA are closely monitoring the flow of water filling of the Delivery Tunnel North in South Africa,” department spokesperson Wisane Mavasa said.
Mavasa added that the tunnel system played a crucial role in supplying water to the Free State and Gauteng provinces, contributing over 400 million m3 of water to the Vaal Dam, annually.
The Ministry of Water and Sanitation is expected to witness the tunnel water outflow at the Ash River Outfall Works on May 25, marking the end of more than seven months of tunnel closure due to maintenance.
