01
City Water System
Cape Town’s water and sanitation services are run directly by the City’s Water and Sanitation Directorate, both water services authority and provider for a metropolitan area of 2,455 km² and 4.77 million people at the 2022 census. It is not a separate company: its finances sit within the City’s budget, and accountability runs through Council. An undated City overview lists 14 dams, 12 water treatment works and 23 wastewater treatment facilities, as well as stormwater and rivers. Its main resource is shared: the Western Cape Water Supply System, a regional network of dams, tunnels and pipelines operated with the national Department of Water and Sanitation and also used by agriculture and neighbouring municipalities.
02
Resources & Supply
More than 95% of Cape Town’s water comes from the Western Cape Water Supply System, whose six major dams hold 898,221 megalitres; minor dams, groundwater and springs supply the rest. The system depends on rainfall, and the drought that peaked in 2018 cut supply from about 900 to about 550 million litres a day.
Demand has since recovered strongly. Total demand, including bulk supply to Stellenbosch and Drakenstein, reached 881 Ml/day in 2024/25, up from 730 Ml/day five years earlier, with reported in-year growth of 5% for 2025/26, above planning assumptions. Its June 2026 outlook expects use to reach allocation within two years. Extreme rainfall also creates pressures: a 1:200-year flood in May 2026 raised dam levels by 10–30% in a week.
03
Wastewater & Stormwater
The directorate treated an average of 605 Ml/day of wastewater in 2024/25, up from 520 Ml/day five years earlier. Capacity is being added where the city is growing: Zandvliet has been expanded to 90 Ml/day using membrane technology, and Potsdam is being enlarged toward 100 Ml/day by 2027. Treatment performance is under pressure. Stormwater and rivers are managed within the same directorate, and a single storm in July 2025 caused widespread flooding that affected more than 4,000 people.
04
Investment & Resilience
The City’s main response to drought is its New Water Programme, adding groundwater, water reuse and desalination to a rain-fed system. Its timetable has slipped: the original aim of about 300 Ml/day of new supply by 2030 is now a projected peak design capacity of 305 Ml/day by December 2036. The City targets national Berg River–Voëlvlei augmentation for 2030, while TCTA reports an advisory phase; Paarden Eiland’s first 70 Ml/day desalination phase targets 2036, with port planning creating site uncertainty. Until about 2030 the City accepts a 1:50-year assurance of supply, against its 1:200-year planning standard. A proposed Infrastructure Stability Programme of more than R10 billion targets ageing bulk assets.
05
Key Challenges
- Managing demand growth as use nears the City’s 346.9 million m³ annual allocation.
- Protecting supply reliability while assurance remains below the City’s 1:200-year standard until about 2030.
- Delivering delayed new sources, with regional augmentation targeted for 2030 and desalination in 2036.
- Renewing ageing bulk infrastructure and closing a R6.7 billion funding gap in the water conservation strategy.
- Restoring wastewater treatment performance while expanding treatment works for a growing city.