The reopening of the Lesotho Highlands tunnel has been delayed by three weeks, owing to maintenance work delays experienced in the Delivery Tunnel South, in Lesotho.

The critical tunnel, which transfers water from Lesotho to South Africa’s Vaal dam, was closed on October 1 for maintenance, with expectations that water would be flowing again on March 31.

However, ever-changing weather patterns and the technical challenges experienced by the implementing agent on the Lesotho side of the tunnel, the Lesotho Highlands Development Agency (LHDA), has caused delays.

One of the challenges experienced was higher than anticipated seepage within the tunnel owing to a change in sandblasting technique – from manual to automated – with high humidity impacting the automated approach.

The contractor is reported to have procured additional equipment to better manage the seepage challenge.

The Department of Water and Sanitation (DWS) previously communicated, early in February, that challenges were faced and that the project was slightly behind schedule, but, at the time, assured that the tunnel would reopen on time.

“The recovery plan was implemented to accelerate the progress of the maintenance work in Lesotho, but the delay could not be avoided,” the DWS said in a statement, noting that the date of the release of water into the tunnel will be announced once the maintenance work is completed.

In South Africa, the maintenance work carried out by the Trans-Caledon Tunnel Authority on the South African side is on schedule and is expected to be finalised on time.

The extension of the tunnel closure will not impact the Integrated Vaal River System’s water resource availability, as the Vaal dam at its full capacity at 101.51% owing to above normal rainfall.

Municipalities along the Liebenbergsvlei river in the Free State, will also not be impacted as the water levels of the Sol Plaatjie (Saulspoort) dam is 82.1%, which means that water can be released from the dam to assist downstream users, if required.

Saulspoort dam will be able to provide water to local communities of Bethlehem, Reitz and Tweeling for a period of up to nine months.