Lawn with a side salad: Rainwater harvesting for self-sufficiency through urban agriculture

In a rapidly urbanising world, urban agriculture has garnered much attention for increasing resilience to a range of interrelated stressors, including climate change, food insecurity, economic instability and most recently, public health crises. Critical to understanding the viability of urban agriculture and ensuring its environmental sustainability, is the intersection of available land and the supply of agricultural inputs. Here, we address existing knowledge gaps related to urban agriculture and rainwater harvesting, by quantifying the self-sufficiency potential of half a million homes in Adelaide, South Australia. We developed a model that combines high resolution spectral and LiDAR imagery with productivity and irrigation data that reflect the actual behaviors of urban growers. Results indicate that 65% of residential properties contain enough available land to provide dietary self-sufficiency of vegetables, while capturing and storing adequate rainwater for irrigation, even in the modelled Dry year scenario. The modelled edible garden and associated storage tank would occupy around half of the lawn space in a typical residential block. These results highlight the substantial contribution urban agriculture can make to a more sustainable food systems in a low-density city.