Towards a water sensitive city. The case of Johannesburg

A research report submitted to the School of Architecture and Planning, Faculty of Engineering and the Built Environment, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Bachelor of Science with Honours in Urban and Regional Planning.The City of Johannesburg is a water scarce city with frequent droughts, flash floods during the rainy season, rising water demands and deteriorating water quality. These water challenges faced by the city of Johannesburg are further aggravated in the context of increased urbanisation, resources constraints and climate change. Green infrastructure includes both natural and engineered or street-level design green infrastructure that mimic natural processes and systems. Green infrastructure is understood as an urban planning and urban design concept for enhancing existing grey infrastructure as well as protecting natural systems and processes. This research report focuses on possible building and street-level design interventions that incorporate green infrastructure, such as bioswales, constructed wetlands, green roofs, permeable paving, raingardens/ bioretention cells and vegetative filter strips. These types green infrastructure which can also be referred to as Water Sensitive Urban Design (WSUD) are identified and discussed in more detail with the aim of alleviating water challenges in the City of Johannesburg. The water management and water provision ecosystem services that are provided by green infrastructure are deliberated on along with the need for green infrastructure to be applied in urban planning. The research report analyses whether water challenges in the City of Johannesburg can be addressed by applying green infrastructure interventions into urban planning. Substantial evidence of WSUD interventions have been provided in the literature review, precedents as well as the case study of the City of Johannesburg. The research report demonstrates the effectiveness of WSUD, when integrated into urban planning, by reviewing the ecosystem services provided by WSUD interventions in the context of the City of Johannesburg. However, the final part of this research report explains some of the challenges faced by the City of Johannesburg, and how to overcome these challenges in order to achieve a Water Sensitive City.KK201