The Cape Flats Managed Aquifer Recharge plant, commissioned by the City of Cape Town, South Africa, was built in response to the city’s water crisis. Designed by SALT Architects, the water treatment plant provides an innovative and sustainable solution that will protect Cape Town’s future water supply. Located within the Pelican Park Section of False Bay Nature Reserve (around 23 kilometres from Cape Town’s city centre), the plant addresses the critical need for sustainable water management. The project is an example of the way in which architecture can respond to essential infrastructural needs with ingenuity and flair.
Enhancing groundwater via innovative filtration
A Managed Aquifer Recharge plant enhances the natural replenishment of groundwater aquifers, geological formations that can contain or transmit groundwater. Groundwater is recharged (replenished) by directing surface water, such as rainwater or treated waste water, into the aquifer, improving water availability and quality.
The new Cape Flats Managed Aquifer Recharge plant sits on a flat sandy expanse bordered by dunes. The area’s strong prevailing south-easterly winds and corrosive coastal conditions informed the project’s design approach.
The Cape Flats Aquifer is recharged by purifying treated effluent to potable standards and injecting this into the aquifer. The process takes place across four linear filtration buildings, aligned parallel to an artificial slope, and using gravity to direct water through the filtration process. At the lowest building, the purified water is redirected to the aquifer.
Architectural language
The long east–west facades of the plant buildings feature angled brick fins and narrow south-facing windows, creating a “gilled” aesthetic. This design filters sunlight while preventing algae growth in the filters.
The administrative building, located at the site’s highest point, is integrated with the first filtration building. It adopts the architectural language of the gilled facade, but is distinguished by the use of a generous brise-soleil. This creates a porous, screen-like structure that filters both light and the transition between inside and outside. It marks an interactive element of the plant, offering a human interface and orienting visitors. Behind the brise-soleil, a double-height glazed atrium provides a light-filled entry space.
The administrative building’s ground floor accommodates functional spaces for plant operators. The first floor houses offices, meeting rooms, and the plant’s control room. Spaces are designed in a manner that is both comfortable and efficient.
Durability and long-term resource efficiency
The mass concrete structures needed for water retention consist of walls and floors up to 600 millimetres in thickness. Acknowledging the design’s significant amount of embedded energy, SALT Architects approached sustainability with a focus on durability and long-term resource efficiency. The studio selected a durable face brick for the facades. The brick’s warm, aesthetic tone harmonises with the sandy surroundings while ensuring minimal maintenance in a corrosive environment. An emphasis on timeless construction improves the longevity of the Managed Aquifer Recharge plant, as well as bolstering its potential for future adaptation, thereby reducing the likelihood of demolition.
Additional sustainable measures include: reusing dune sand from site excavations as backfill, installing low-flow sanitary fittings and waterless urinals, and optimising passive thermal strategies that reduce the need for artificial climate control.
Celebrating the importance of infrastructure
Access to the plant is restricted, however SALT Architects has designed a project that extends beyond a utilitarian facility to celebrate the importance of infrastructure. “By elevating the experience of its operators and crafting a setting of thoughtfulness and beauty, the project communicates care and inspires pride,” explains the studio. “Its design ensures it can host educational groups and visitors, serving as a tangible example of resilience in the face of water scarcity.”
