Australian cities are expanding rapidly due to a population growth of 25% over the past 20 years. The development of healthy and sustainable cities has become an increasingly important challenge for urban planners, and integrated approaches to planning and design are currently being sought. One such approach is Water Sensitive Urban Design (WSUD), which incorporates sustainable water management systems and practices into the urban landscape. While there are many case studies on the incorporation of WSUD into greenfield development sites, there are few investigations of the potential for water quality improvement that can be achieved by retrofitting existing developments with WSUD. This study investigates the use of hydrological modelling techniques to quantify the water quality benefits of retrofitting WSUD into an existing streetscape in the Adelaide central business district. The results show a need for enhancing the performance of the current hydrological modelling tools for planning and design of permeable pavements and also a need for developing tools to design bioretention systems. The outcomes of this study will lead to an enhancement of current knowledge on the potential for water quality improvement that can be achieved by using bioretention systems and permeable pavements with underlying storage in urban landscapes.

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