Cape Town treated 605 million litres of wastewater a day in 2024/25, up from 520 Ml/day in 2020/21. Over the same period its Green Drop wastewater score fell to 75% in the 2024 audit cycle. That moved the City from "good" to "average", its lowest score to date.
Capacity is not the constraint
The City runs 23 wastewater treatment facilities and reports 22.4% of its treatment capacity unused. It is still expanding. Zandvliet reached 90 Ml/day in 2024. Potsdam is being doubled from 47 to 100 Ml/day, with a 2027 target, and Macassar is planned to grow from 34 to 80 Ml/day. As recently as February 2025, Parliament's water committee held Cape Town up as the benchmark for wastewater management in South Africa.
Rivers are moving the wrong way
Only 55.8% of river and vlei samples met the E. coli standard in 2025, down from 57% a year earlier and short of the City's 60% target. In September 2025 the Kuils and Salt rivers were under 35% compliant. Sewer blockages fell from more than 130,000 in 2020/21 to fewer than 88,000 in 2024/25, but overflows and stormwater entering sewers still reach rivers.
Why it now matters for drinking water
Treated wastewater is about to become a drinking water source. The Faure New Water Scheme would purify 70 Ml/day of recycled water from June 2031, rising to 100 Ml/day. Its qualification stage opened on 25 September 2026. The money is thin: the wastewater segment made a surplus of R22.8 million on revenue of R5.61 billion in 2023/24, against R1.73 billion for water.
Which plants carry the most risk, how long the upgrades will take to show up in compliance, and what a weaker Green Drop position means for the Faure partnership and for Cape Town's wider supply plan are questions the report answers. The full report, Cape Town Water Intelligence Report, is available for USD 799 at https://ourfuturewaterintelligence.com/reports/cape-town-water-intelligence-report. For a free overview, see https://ourfuturewaterintelligence.com/cities/cape-town.