In the Namib Desert, a small dark beetle climbs onto a dune, encountering misty wind, and bends its body. Droplets settle on its hardened outer wings and flow towards its mouth.
For South African designer Shakira Jassat, this survival strategy suggested an alternative approach to building design: could building surfaces also collect water?
Her answer is the Aquatecture Water Harvesting system, which consists of modular panels installed on building facades to collect rainwater. These panels direct water through downspouts into storage reservoirs, turning vertical surfaces into collection zones.
The initial idea arose when Jassat observed rain running down bricks opposite her home. She wondered how buildings could capture this water instead of diverting it.
Traditional rainwater harvesting usually relies on roofs and gutters. However, Aquatecture uses facades, which, in Jassat's opinion, presents a special opportunity for high-rise buildings and other structures with large vertical surfaces. Water flows through the panels by gravity into a storage tank. Removable downspout sections allow for cleaning. The long-term goal of the system is to provide water for non-potable needs, such as toilet flushing and use in washing machines.
For Jassat, integrating the system into the architectural language is as important as collecting water. The concept developed parallel to Jassat's research into other methods of atmospheric moisture collection, including studying fog and humidity collection technologies, in collaboration with the Faculty of Engineering at Eindhoven University of Technology. A semester student study tested the possibility of collecting water vapor on panels in South Africa; the results showed it was possible but insufficient to support the entire concept.
Collected rainwater is used for shrub irrigation
Collecting rainwater proved to be a more practical option. The project then moved to a pilot phase. Engineers Without Borders participated after an engineer working on the V&A project connected them with Jassat. In 2021, she selected ten students from the Engineers Without Borders student society at the University of Cape Town, representing various disciplines including geomatics, humanities, mechanical engineering, civil and chemical engineering, to study and evaluate the Aquatecture pilot installation.
The pilot installation was placed in a parking lot in the V&A Waterfront area, opposite the Orange Street Farmers Market. Students regularly visited the site to monitor the water level in the tank and the amount of precipitation, collecting data to assess the installation's water collection capacity. The project reached an early milestone when the storage tank, sponsored by JoJo South Africa, filled with collected rainwater. Students connected a hose to the tank, and the water was used to irrigate shrubs at the nearby Orange Street Farmers Market.
However, the pilot project also revealed difficulties in measuring the volume of collected water. Wind, in particular, complicated forecasts, forcing researchers to consider how changing conditions affect the relationship between precipitation amounts and collection capacity. The study also examined the environmental impact of the system's materials. With limited and incomplete local data on embodied carbon, researchers worked with suppliers and transport companies to gather information on recycled materials and calculate the pilot's embodied carbon. The resulting data was intended to help determine adjustments to reduce emissions in the final product. This work allowed the project to test the system in a real urban environment while simultaneously studying issues of materials, environmental impact, maintenance, and performance.
Pilot project attracts attention
The pilot installation in the Waterfront in Cape Town remains in place, and the collected water is used for plant irrigation. Jassat notes that she appreciates that people can use the space without necessarily noticing the water supply infrastructure. The goal was to demonstrate that water supply infrastructure does not have to be visually separate from architecture.
Jassat says that Aquatecture has attracted significant interest. It has been showcased at Dutch Design Week and many other exhibitions, and it has received media coverage, but she would like this attention to translate into practical application. She notes: 'I would like to have a greater impact than just attracting attention in this project.'
The challenge, she says, arises when interest needs to transition into investment, manufacturing, and construction.
Manufacturing has become one of the central issues. Jassat aims for the system to be produced as locally as possible. Interest in the technology spread to Kenya through an architect working there, but Kenyan manufacturers were unable to produce the system. This prompted further investigation into local production sites for panels in South Africa and other parts of the continent, while Jassat is also considering manufacturers in India and China. The production process itself must adhere to the principles of the technology, which implies considering materials, durability, and the ability to maintain the system over time.
Somelese Mbele, who worked with the student group alongside Jassat within the Engineers Without Borders project and participated in the field studies of the pilot phase, stated that the feasibility and accessibility of modular wall rainwater harvesting heavily depend on materials, manufacturing, and local supply. Engineering requirements are equally important. Panels must withstand weather, UV radiation, corrosion, and physical damage. Collection and storage systems must remain accessible for cleaning, and structural connections must be designed with safety and durability in mind. Collection and storage systems must also be 'easy to clean and maintain and minimize clogging.'
Mbele added that 'decentralized water collection systems should not necessarily be seen as a replacement for large-scale municipal infrastructure. Rather, they can complement existing systems, increasing resilience and reducing the load on centralized water sources.'
Too early to talk about the scale of impact
Dr. Ferrial Adam, CEO of WaterCan, believes the broader issue is designing buildings that consume less water, alongside finding additional sources. Alternative sources can be viewed as a sustainability factor, but this does not solve the question of how much water development consumes. She argues: 'We really need to consider how to save water, how to build future buildings that use less water.'
Adam insists that water crisis resilience must be integrated into development, not added afterward. This can include reusing water within buildings, such as directing water from handwashing into toilet tanks, alongside rainwater harvesting. Adam believes this approach should also cover poor communities, where water tanks, cisterns, and community or temporary sanitation facilities often serve as a response to inadequate services. She sees a similar need in industry, mining, and agriculture: when designing more sustainable systems, water consumption and pollution must be considered.
For Aquatecture, wider adoption requires the willingness of developers to invest, and manufacturers capable of producing panels and systems that users can maintain. Funding remains a hurdle. Jassat primarily self-funded the development, apart from support for pilot projects. A Johannesburg developer expressed interest but questioned the readiness of clients to invest. The project is not yet ready for the market. Its pilots show that the system can be built and tested, but Jassat believes it is too early to claim measurable impact on a full scale. She continues to work on materials, manufacturing, funding, and partnerships. For her, success will be measured by whether the system provides: 'When it collects water and flushes these toilets, that is success for me.'