The Gauteng City-Region (GCR) is South Africa's largest consumer of resources and materials and plays a major role in perpetrating the country's trajectory of unsustainable consumption. Viewing the city-region as a living organism, with a metabolism of resource inputs (e.g. water, energy, food and raw materials), internal functions and waste outputs (e.g. waste, sewage and pollution), is a useful way of understanding the sustainability challenges facing SA's key population and economic centre. The region will face a resource crises in the years to come if it cannot fundamentally change its built form and overhaul its infrastructure networks. This challenge is exacerbated by the fact that there are many communities in the city-region that still lack decent shelter and basic services, and many areas where infrastructure needs to be expanded because capacity limitations constrain development.

This section sets out the context for this challenge and discusses key aspects of it. It also reviews related issues such environmental risks and vulnerabilities facing certain settlements.