Brief
Lesotho Highlands Water Project construction linked to river pollution concerns
Observers say wastewater from the Polihali tunnel construction is entering the Sekoai River, raising fears of contamination of downstream water supplies.
By Felo News Desk · Published
Concern persists that construction at the Lesotho Highlands Water Project is polluting the Sekoai River in Mokhotlong, Lesotho, according to a report by Bizcommunity on 16 October 2026.
What happened
In May 2025, the Kopano Ke Matla Joint Venture, responsible for building the Polihali transfer tunnel, was suspended after the Lesotho Highlands Development Authority (LHDA) found oily and acidic wastewater being discharged into nearby rivers and the Katse reservoir. The suspension sent home about 1,400 workers on the M42 billion project that supplies drinking water to South Africa.
During an August 2026 site visit, observers noted wastewater flowing from the tunnel boring machine access adit at the Polihali tunnel site, with the perimeter fence only about 10 m from the river. The water appeared to run continuously from an outlet pipe onto land before reaching the river.
On 7 September 2026, residents of the Tloha‑re‑Buoe village reported seeing foamy white bubbles in the Sekoai River near the same tunnel access area. Villager Thomello Ramotloenya said he went to the river that morning to graze his animals and found the water covered in foam.
What was said
Ramotloenya told the outlet, "I went to the river that morning to graze my animals only to find foamy white bubbles in the river." The LHDA said it will forward the evidence of suspected pollution collected by GroundUp to the project engineer for inspection and testing.
How it came about
GroundUp previously reported that the contractor’s wastewater‑treatment systems were non‑compliant despite repeated warnings. A suspension letter dated 5 May 2025 listed 26 non‑compliant issues, of which only three had been addressed. Problems included missing effluent test results, a malfunctioning sulphuric‑acid dosing pump, high pH levels, and oil contamination. Earlier reporting by GroundUp also highlighted untreated construction wastewater being discharged into the Ntšupe River and untreated tunnel effluent entering the Katse reservoir.
Key facts
- The Lesotho Highlands Development Authority suspended the contractor in May 2025 for discharging oily and acidic wastewater. (bizcommunity.com)
- Residents reported foamy water in the Sekoai River on 7 September 2026. (bizcommunity.com)
- The LHDA will refer the suspected pollution evidence to the project engineer for testing. (bizcommunity.com)
Timeline
- 2025-05-05 — Suspension letter cited only three of 26 non‑compliant issues addressed.
- 2025-05-?? — Contractor suspended for oily and acidic wastewater discharge.
- 2026-08-?? — Observers noted wastewater flowing from tunnel access adit near the river.
- 2026-09-07 — Villagers reported foamy water in the Sekoai River.
Sources
- [1] bizcommunity.com — originally reported as “Is construction at the Lesotho Highlands Water project polluting rivers?”
