Potsdam reaches 60% completion
Potsdam Wastewater Treatment Works (WWTW) in Milnerton, currently one of the Western Cape’s largest infrastructure projects at a cost of R5,2 billion, has reached 60% completion. Construction began in April 2023 and is progressing on schedule. It is expected to be completed in late 2027.
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The City of Cape Town has confirmed that construction of the R5.2 billion upgrade to the Potsdam Wastewater Treatment Works (WWTW) in Milnerton has passed the 60% completion mark, with the project on track for delivery in late 2027.
Launched in April 2023, the upgrade is regarded as one of the metro’s largest infrastructure undertakings and is intended to “future-proof” essential water and sanitation services for a rapidly growing population.
Once completed, Potsdam’s treatment capacity will more than double, increasing from 47 million litres to 100 million litres per day, said the City in a statement.
The expansion is expected to accommodate urban growth, improve effluent quality discharged into the Diep River and Milnerton Lagoon, and broaden access to treated water for reuse in agriculture, industry, and recreation.
According to the City, several milestones have already been achieved:
• Ultrafiltration plant: Entered a one-year trial in June 2025, testing new micro-screening, ultrafiltration membranes, and UV disinfection systems.
• Treated effluent pump station: Construction is complete, with supply to Milnerton, Century City, and surrounding areas expected after final testing.
• Dewatering plant: Commissioned in May 2025 and operating on a partial basis.
The City's mayoral committee member for water and sanitation, Zahid Badroodien, described the upgrade as a critical breakthrough for the city’s infrastructure.
“Over the next three years, Cape Town will invest R16.4 billion in water and sanitation – more than Johannesburg and Durban combined,” he said.
“This project shows our commitment to delivering results on time and to the highest standards. Restoring the health of the Milnerton Lagoon and improving water quality in the catchment remain top priorities.”
He said that Potsdam has been under strain from inflows exceeding its design capacity, as well as sand ingress from sewer collapses – challenges the upgrade is expected to resolve.
Full trial operations are scheduled for October 2026, he said.