By September 2026, R24 billion of the R53 billion allocated to Lesotho Highlands Phase II had been spent. Polihali Dam was 53% complete and the 38 km transfer tunnel to Katse had reached 58%. The project will raise transfers into the Vaal system from 780 million to 1,270 million cubic meters a year.
Why Gauteng is waiting
Rand Water's abstraction from the Integrated Vaal River System is capped at 1,803 million cubic meters a year, a daily average of about 4,940 ML/d. In March 2025 Rand Water described itself as drawing about 1,800 million cubic meters a year under a temporary license, against 1,600 million authorized. The 19 dams of the Vaal system were 97.1% full on October 6, 2026, but full dams do not lift a license.
The timetable
Polihali Dam is expected to begin impounding in July 2027. A second tunnel boring machine was launched at Polihali on April 20, 2026, but excavation has slowed because of difficult geology. Rand Water's FY 2025 annual report targets completion in October 2028. The Minister has ruled out extensions beyond 2028/2029, on a project already nine years behind its original timetable.
After Lesotho
The extra 490 million cubic meters a year is not the last large step Rand Water expects from surface water. It states that the Vaal system will not be augmented after the Drakensberg scheme, around 2042. In March 2025 it listed 785 ML/d of alternative options, from wastewater reclamation to boreholes and acid mine drainage, all still being explored.
How the resource, institutional and municipal tiers of Gauteng's water system fit together, and where the system's weak links lie until 2028, are examined in the report. The full report, Water Systems Overview: Rand Water, is available for USD 499. For a free overview, read the Rand Water Utility Snapshot.