Retaining and recycling water to address water scarcity in the City of Cape Town
Amoré van Zyl, Johannes L. Jooste
Abstract
Conventional water management strategies, where water is extracted, used and then disposed of are no longer enough to address water shortage in cities. Climate change, population growth and economic development are putting available water resources under pressure. A system dynamics model of the City of Cape Town’s water system serves as a case study to evaluate policy interventions, aimed at extracting value from retainable and recyclable water sources to address the growing water shortage experienced in cities. Retention of rainwater, the reuse of greywater and the treatment of wastewater for reuse, are identified as potential water sources. The results provide insight into the behavioural response of the water system, by evaluating the water supply stress and cost of policy interventions related to these alternative sources. It is concluded that only a combination of conservation management and water retention and recycling will reduce water stress over the long term.