The Value of Integrating Water Management and Urban Infrastructure

Abstract

Water management in cities is changing as a result of climate change and increasing urbanisation. Instead of a “big pipes in, big pipes out” approach which imports water from the river basin into the city and discharges sewage water downstream, more and more the city itself is seen as a catchment and urban runoff as a resource. This requires a different approach to urban water management, which integrates water in urban infrastructure and planning. In addition to purely managing stormwater and urban water resources the water sensitive design approaches that have emerged increasingly have recreational and social goals. Urban infrastructure such as rain gardens, green roofs and retention ponds have an aesthetic and recreational function and can help making people aware of the preciousness of water. Yet, new approaches are often more complex and expensive than conventional urban water infrastructure and with long time horizons make a good trade-off between costs and benefits is difficult. Although the environmental, social and engineering benefits seem obvious, expressing it in monetary terms is challenging with standard economic methods. Based on the ABC Waters Programme in Singapore, several alternative methods for valuing new types of infrastructure are explored and methodological challenges identified.