History of Water Sensitive Urban Design/Low Impact Development Adoption in Australia and Internationally

Abstract

Abstract Since the 1980s, urban planning and development has increasingly taken account of natural water and nutrient cycles, with water flows managed as would have occurred on the original greenfield site, emulating the original ecosystem. However, other drivers deriving from the impact of urban development and increased human activity include • managing stormwater quality, • mitigating a risk of increased flooding, especially where there had been some previous history of them in the greenfield environment, • harvesting of rainwater and stormwater for potable and nonpotable use, • greening the urban environment to reduce the heat island effect generated by intensive urban development and increased pavements, and • improving the aesthetics of the urban environment to encourage a feeling of well-being in the community. These philosophies were developed in North America as Low Impact Development and later Green Infrastructure (which sometimes also assumes a consideration of energy management) in response to the 1972 passage of the Clean Water Act (US). Planning may incorporate green roofs, rain gardens, swales, permeable pavements, wetlands, green spaces, and urban natural vegetation corridors. Britain adopted Sustainable Urban Drainage Systems (SuDS) techniques. In Europe, planners and local government respond to the European Union Water Management and Flooding Directives on a river basin basis. In Australia, similar policy developments took place under the philosophy of Water Sensitive Urban Design (WSUD). The components and drivers vary between communities, each choosing emphases appropriate to their catchments, infrastructure, seasonal climate, local water cycle, and social expectations. Cities in East Asia have been undergoing rapid urbanization over the past 40\xa0years, often accompanied by increased flooding, especially in China. In 2013, China introduced new urban policies which included the concept of Sponge Cities where “stormwater can be naturally conserved, infiltrated, and purified” for potential reuse, thereby reducing flood risks and increasing water availability. Construction guidelines were issued. Thirty major cities are participating as pilot cities. Each is eligible for central government subsidies. In Africa, the term Water-Sensitive Settlements has been suggested as the WSUD approach as originally envisaged does not take cognizance of the “developmental” or “equity” issues, which are particularly important in developing countries that may have legacies from their colonial or apartheid past. Many countries are now beginning to consider the necessity for WSUD in their cities and settlements. Addressing technical integration problems, legislative constraints, social equity, and community acceptance will be necessary for them to develop Water Sensitive Cities. This chapter summarizes the history of WSUD adoption and examples of the approach that has been taken across the globe.