AQUATECTURE: WHEN BUILDINGS CAPTURE RAIN
The end of 2020 saw the beginning of an exciting pilot project in Cape Town, the first installation of Studio Sway’s ‘Aquatecture’ rain harvesting panels. They are designed to catch rainwater which can be channelled into buildings to form part of greywater systems or stored for later use. This innovation is the brainchild of Netherlands-based South African designer Shaakira Jassat, founder of Studio Sway. Jassat’s studio aims to combine scientific research and aesthetic design. Realising that fresh water is a limited resource and challenged by her first-hand experience of Cape Town’s water crisis, when she attended the 2018 Design Indaba, she has been focussing her research on how to address this social and environmental issue through building technology and design. Inspired by plants and insects that catch and store rainwater or draw water from the air, she started developing prototypes for ‘Aquatecture’.
The first full-scale pilot has seen the installation of these specialised panels on the side of a parking structure at the V&A Waterfront in Cape Town. Jassat worked with façade engineer Adam Ozinsky, to engineer the prototypes for full scale application. Geustyn and Horak sponsored the material, manufacture and installation of the panels, which are designed to be installed as either cladding for urban structures or as free-standing elements in open spaces. In the current test installation it is manufactured from aluminium. The installation includes a weather station as well as a gutter and piping, sponsored by Longspan Gutters and AWR Smith Process Instrumentation, which channels water to an above-ground tank sponsored by Jojo. The research, done by Jassat in collaboration with UCT’s ‘Engineers Without Borders’ and facilitated by GBCSA’s Jo Anderson, will take place over the next two years. During that time weather and rainfall data will be collected, and panel efficiency and impact on the surrounding environment will be recorded. Once the data is collected, the panels can be further refined and eventually manufactured in South Africa on a larger scale. To stay informed, sign up for updates by clicking here.
Net zero water use in a building – where enough water is harvested or recycled on site to cover the building’s own water requirements – used to seem like an impossible target. However, new projects are targeting GBCSA’s Net Positive Water certification. GBCSA considers a site net positive when the water recycled or produced on site is greater than the water consumed. The International Living Future Institute’s Living Building Challenge takes this further and requires that all wastewater and stormwater must be treated on site, without chemicals and managed through reuse, a closed-loop system, or filtration. A water system installed on a site should also aim to match the natural cycles of that site as closely as possible – that is, the percentages of water leaving a site through filtration, evaporation, or run-off should mimic what would happen were there to be no building there at all.
Legaro Property Development’s 76 Corlett Drive, in Johannesburg, is hoping to become the highest rated Green Star building in Johannesburg and is targeting Petal Certification of the Living Building Challenge, including the Water Petal. Rainwater will be harvested and stored for potable use, then greywater and blackwater will undergo ecological treatment and be re-used for non-potable requirements. Soft landscaping and a planted façade will assist in matching nature by ensuring enough rainwater and irrigation leaves the site through evaporation and infiltration, reducing site runoff.
WATER FROM AIR
Two exciting technologies are pulling water from thin air. SOG Water Solutions, a Cape Town based start-up, has been making advances in the field of Atmospheric Water Generation (AWG). This technology is not new, but historically it has not been very effective in dry climates. More recent advances have meant that the system can be successfully utilised much more widely, especially in the South African context. A compact machine draws air in, cools it to condense the water and collect it in a tank and then pumps out the dry air. This is proving to be a very efficient method of producing drinking water. It can also be attached to a solar power installation, making it a completely off-grid installation. SOG Water Solutions
The City of Cape Town has started a fog harvesting pilot project on Table Mountain. The idea is to catch the water droplets that make up Table Mountain’s famous fog ‘table cloth’ on vertical mesh screens and allow it to trickle down into a collection chamber. The first phase pilot plant, completed in 2019, provided preliminary data and the second phase pilot plant has just been completed. Sampling will commence for both plants from 2021. For the next two years the water quality and meteorological data from the plants will be analysed. The hope is that this may be a viable option for augmenting the city’s drinking water supply.
ARUMLOO: FLUSHING EFFICIENCY
In 2018 the ‘Arumloo’ made headlines as a new, low-flush toilet designed by Isidima Design & Development in Cape Town. Since then the toilet has undergone 250 successful trials. The toilet’s ‘Vortex’ flushing design was inspired by the shape of the arum lily and enables a reliable flush using less than two litres of water, far less than most toilets on the market. Plastic versions of the ‘Arumloo’ are expected to be released by the middle of 2021, with ceramic versions to be available later in the year. The Arumloo’s low-flush technology is inspired by the arum lily. Arumloo
Hydraloop Decentralised Water Recycling
The way we utilise and discard water in a modern urban environment is both wasteful and labour intensive. Centralised water treatment plants require huge amounts of infrastructure and maintenance. ‘Hydraloop’ brings greywater recycling closer to home. This decentralised water treatment system allows greywater to be collected, treated, and reused on site, allowing a household or business to recycle up to 85% of its water which reduces tap water volumes by up to 45%.
The treatment system is contained within an attractive appliance, similar in size to a freestanding fridge. It can also be installed on a larger scale with multiple units used to treat greywater for student housing or hotels. Greywater from showers, baths, and washing machines is collected and treated in the unit’s six-step process, after which it is available for reuse in the home, garden, or pool. The system is low maintenance and requires no consumables. Processes are remotely monitored, allowing easy support, proactive maintenance advice, and software updates. WATCH VIDEO HERE | www.hydraloop.com
Guidelines for Sustainable Water Drainage
South Africa’s draft guidelines for Sustainable urban Drainage Systems (SuDS) were published in 2016. Based on research by UCT’s Urban Water Management Department, the guidelines suggest how to better deal with stormwater run-off in our cities, breaking away from the traditional canalised systems. Rand Water recently released an outline of easy steps to achieve the set goals, many of which are especially easy to include in new developments. Rainwater harvesting provides useable water while water efficient irrigation also reduces run-off, as does innovative use of planting in the example of green roofs. Permeable surfaces increase filtration rather than surface water, effectively cleaning stormwater and returning it to groundwater reserves. Water Wise
Smart irrigation systems save water by using it only when and where it’s needed. They can automatically water different zones for different lengths of time and can test soil water contents and make adjustments accordingly. Timers allow night watering to reduce evaporation and are programmed to account for seasonal variations.
While modern technology is saving water in large-scale irrigation installations, sometimes a classic approach is more accessible for small gardens. Just as ‘slow food’ has made a comeback, The Pod Project is giving ancient irrigation techniques a new lease on life. Briony Fickling, The Pod Project’s founder, researched ancient sub-surface irrigation methods that water plants at their roots, where it’s needed, reducing water loss from surface run-off and evaporation. When nothing was locally available, she made her own. Bulbous, locally made, unglazed terracotta pots with narrow necks are buried in the soil up to the neck, filled with water and closed with a lid. The water slowly seeps through the clay into the soil as the plants need it. The Pod Project
AFRICA’S LARGEST WATER TANK
Water storage, particularly when the water needs to last through dry seasons, is especially important for remote agricultural settings. Abeco Tanks, a leader in water storage solutions, recently completed the largest water storage tank in Africa. This 5.8m litre tank, in conjunction with a 3m litre supplementary tank, supplies one of South Africa’s biggest poultry producers with storage capacity for 8.8m litres of water. That’s roughly 3.5 Olympic swimming pools. The rectangular, sectional, bolted tank is modular, making transport and installation easy. It was installed in the record time of only 38 days (as opposed to 128) and is hygienic and safe for livestock and the processing plant. Processing Plant