Contemplating urban water management in cities of the future

Recent occurrences in Australia of severe droughts, heatwave conditions and floods highlight the vulnerability of future cities (and towns) to the chronic and acute effects of climatic extremes. Global population continues to rise and by mid-century, 70% of world population will live in cities. The economic, environmental and social impacts of climatic extremes are exacerbated by increasing urban densities and associated anthropogenic pressures on a city’s water system. These emerging challenges manifest into such questions as: the capacity of a city’s natural water resources to support a growing population; the vulnerability of these natural resources to climate change and urban pollution; the institutional and community capacity for transformative change to become more resilient; and ultimately, the question of the liveability of the city.

The long-term productivity, prosperity and liveability of cities and towns are fundamentally underpinned by the sustainability (carrying capacity) and resilience (coping capacity) of the city. The quality of living in these environments defines its liveability (comfort capacity). Each of these city attributes is interrelated and self-reinforcing but can also be at risk of being mutually competing when individual objectives are pursued without due consideration to broader dynamics of city development.

Concepts of water sensitive cities are emerging in city-shaping policies and responding to a general consensus that existing water services and planning processes are poorly equipped to support projected population growth and slow to respond to economic and/or climatic uncertainty. In essence, cities were trying to meet 21st-century challenges by reinvesting in 19th-century strategies and infrastructures. For example, it is increasingly difficult and inappropriate to adopt a traditional economic-risk management approach to infrastructure planning and development when planning for occurrences of events for which there may not be probabilistic profiles.

Our cities and towns have always been the platform of ‘social-technical experiments’ and the intersection of competing and complementary objectives. Urban planning and design is the discipline that integrates the emerging and expanding urban water objectives. The words ‘urban design’ have never been more prominent in our water sensitive urban design journey. What is clear is that water sensitive urban design is the process and water sensitive cities are the outcome.

A water sensitive city will be a collection of interconnected water sensitive precincts. In each one, site-specific plans will be developed to respond to local opportunities and constraints. These precincts will: efficiently use the diversity of water resources available; enhance and protect the health of urban and natural waterways; and mitigate against flood risk and damage. Public spaces are green infrastructure that harvest, clean and recycle water, increase biodiversity, support carbon sequestration and reduce urban heat island effects.

Realising the vision for a water sensitive city will require a major sociotechnical overhaul of conventional approaches to urban water management. It requires the transformation of urban water systems from a focus on water supply and wastewater disposal to more complex, flexible systems that: integrate various sources of water; operate through a combination of centralised and decentralised systems; deliver a wider range of services to communities (eg, ecosystem services, urban heat mitigation); and integrate into urban design.

A new or expanded economic valuation framework for assessing land and water projects will be required to account for the many benefits (externalities) associated with contemporary urban water management. This requires us to draw the connections between urban water management and urban liveability and to quantify their benefits. The framework will also identify the direct and indirect (community) beneficiaries and provide the basis for public/private investment in these projects.

Adaptive and integrated management approaches offer an alternative to the traditional urban water regime and present alternative urban water governance frameworks to support more sustainable and resilient practices. Sustainable urban water management regimes would emphasise a systems approach with interconnections between the management of the urban water streams and other related urban water governance functions such as land use planning, urban design, infrastructure delivery and maintenance, project financing etc. The ultimate objective is to deliver initiatives that underpin the sustainability, resilience and liveability of cities, the foundational attributes of cities of the future.

*Professor Tony Wong is Chief Executive Officer of the Cooperative Research Centre for Water Sensitive Cities. He is internationally recognised for his research and practice in the sustainable urban water management, particularly in Water Sensitive Urban Design. His expertise has been gained through national and international consulting, research and academia, and he has led a large number of award-winning urban design projects in Australia and overseas. He has been commended for having defined “a new paradigm for design of urban environments that blends creativity with technical and scientific rigour”. In October 2010, Prof Wong was presented by the Institution of Engineers, Australia with the prestigious Sir John Holland Award as Australia’s 2010 Civil Engineer of the Year. In presenting the award, the Chair of the Civil College Board described Prof Wong as “a visionary who, throughout his career, has been an effective thought leader who continues to encourage his colleagues and clients through his passion and dedication to building sustainable environments”.