A Cross-Border Water Scheme That Supplies South Africa, and a Contractor Already Suspended Once for Dumping Wastewater
On the morning of 7 September, Thomello Ramotloenya took his animals down to the Sekoai River near Tloha-re-Buoe, in Lesotho’s Mokhotlong district, to graze. He found foamy white bubbles floating on the water. Other residents of the village said they had seen foamy water flowing in the same stretch of river. Close by lies a tunnel access site of the Lesotho Highlands Water Project, the cross-border scheme whose Katse reservoir supplies drinking water to South Africa. There, a contractor is building the Polihali transfer tunnel.
The contractor building the tunnel, the Kopano Ke Matla Joint Venture, has been here before. In May 2025, it was suspended for discharging oily and acidic wastewater into nearby rivers and into the Katse reservoir, which supplies drinking water to South Africa. The suspension sent 1,400 workers home on the M42-billion project, a joint undertaking between Lesotho and South Africa (one loti is equal to one rand). Work resumed later that month. Now fresh questions are being asked about whether the problems were fixed.
What Was Seen in August
Journalists from an investigative reporting center who visited Mokhotlong in August observed wastewater being discharged from the contractor’s tunnel boring machine access adit at Polihali. The perimeter fence is about ten meters from the river, and the wastewater appeared to flow continuously from an outlet pipe onto the land before reaching the river. These observations come from a single reporting team and have not yet been confirmed by laboratory tests, a point the project authority itself makes. The Lesotho Highlands Development Authority (LHDA) has said it will refer the evidence of suspected pollution to the project engineer for inspection and testing.
The history explains why the observations draw attention. A suspension letter dated 5 May 2025 stated that the contractor had addressed only three of 26 issues identified as non-compliant. They included missing effluent test results, a malfunctioning sulphuric acid dosing pump, high pH levels in treated water, and evidence of oil contamination. The supervising engineers had raised concerns about untreated construction wastewater being discharged into the Ntšupe River, untreated tunnel effluent reaching the Katse reservoir, and failures to maintain sewage and wastewater-treatment plants.
The Authority’s Answer
The LHDA’s account is very different. Its spokesperson, Mpho Brown, said the 2025 suspension “was a precautionary and corrective step, taken to address identified shortcomings in wastewater treatment before they could result in harm”. Work resumed on 25 May 2025 after the project engineer inspected the upgrades, and independent laboratory results confirmed that the contractor’s treated effluent met the required standards, he said. The contractor was required to add settling capacity and a pH correction stage, revise its operating procedures and appoint a qualified process specialist to run the plant.
Responding on behalf of the contractor, Brown said the outlet observed in August is the plant’s designated discharge point, an approved and monitored part of the treatment system through which only treated effluent is released. “The LHDA has received no complaints or reports of foaming, discoloration or pollution of the Sekoai River linked to the works,” he said. He acknowledged that an inspection and tests had not yet been carried out, and said that if non-compliant effluent were found, the discharge would be stopped immediately and the contractor required to correct the cause. “The LHDA will take whatever further action the contract allows,” he said. Brown did not respond to follow-up questions. The two accounts therefore remain unreconciled: villagers describe foam, while the authority says it has received no complaints and that the outlet is approved.
Why South Africa Is Watching
The stakes extend well beyond Mokhotlong. In May 2025, the office of South Africa’s Minister of Water and Sanitation, Pemmy Majodina, said the suspension had been prompted by “persistent failures to meet treatment standards across multiple sites, despite prior warnings and formal Non-Conformance Reports”. South Africa’s Democratic Alliance called at the time for the Auditor-General to investigate financial and environmental concerns around the project, warning that pollution posed serious risks to a water supply on which millions of South Africans rely. The party pointed to Gauteng, the Free State, the North West and beyond, and noted that municipalities already owe water boards more than R28 billion.
The Water Belongs to the People Who Live Beside It
The Lesotho Highlands Water Project is a joint undertaking between two neighbors, and its Katse reservoir supplies drinking water to South Africa. At the same time, a contractor’s wastewater could affect millions of people who rely on that supply. But the communities of Mokhotlong live next to the construction, drink from and graze beside its rivers, and bear its risks first. The test promised by the LHDA should be carried out quickly, by an independent laboratory, with results published for residents to see. If the effluent is clean, publication will restore trust. If it is not, the contract gives the authority the power to stop the discharge, and it should use it. Control over Lesotho’s water resources means little if the people of the highlands cannot be sure the river at their doorstep is safe.
