City of Cape Town, Western Cape Province, South Africa – In construction groundwater augmentation using natural aquifer recharge and recycled water
The Cape Flats scheme aims to provide a world class, robust integrated water scheme for sustainable urban aquifer management that is easily operated and maintained, optimised in terms of cost effectiveness, enabling socio-economic benefits for all stakeholders and making a positive environmental contribution.
Water reuse is a major feature of the City of Cape Town’s Water Strategy, “Our shared water future”. The City is committed to maximising the reuse of wastewater in line with the second edition of the National Water Resource Strategy (2013) to meet current and future water demand. The 10-year committed program includes future plans for the use of treated wastewater to recharge the Cape Flats aquifer.
Cape Flats Aquifer: Water scheme overview and configuration
The Cape Flats aquifer is a sandy, shallow, unconfined aquifer with boreholes approximately 40 metres deep. The Cape Flats Abstraction and Managed Aquifer Recharge groundwater scheme is being incrementally developed. A projected 50 million litres (13.2 million gallons) per day of drinking water from the scheme is anticipated in Phase 1 and Phase 2. The aquifer will be recharged at a rate of up to 40 million litres (10.5 million gallons) per day.
The scheme is divided into discrete clusters, with the remaining open spaces within the urban landscape. The clusters and their sustainable yields are:
- Hanover Park – 4 million litres (1 million gallons) per day
- Philippi – 6 million litres (1.5 million gallons) per day
- Strandfontein West – 5 million litres (1.3 million gallons) per day
- Mitchells Plain – 30 million litres (7.8 million gallons) per day
The Managed Aquifer Recharge component includes the treatment and injection of recycled water into strategic zones of the aquifer, to ensure sustainability of the aquifer biome over the long term. The Managed Aquifer Recharge infrastructure consists of a Reclamation Works with an initial capacity of 40 million litres (10.5 million gallons) per day situated at the Cape Flats Wastewater Treatment Works, a pump station, conveyance pipelines, injection boreholes and infiltration ponds. The capacity of the Reclamation Works is upgradeable to 64 million litres (16.9 million gallons) per day.
Environmental monitoring committees will be set up to oversee longer-term sustainability, while water monitoring protocols will be put in place to ensure water quality compliance. All water entering Cape Town’s piped network and intended for drinking is treated to meet the minimum national water quality standards in terms of South African National Standard 241 and World Health Organization standards.
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