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ECONOMIC DEVELOPMENT AND WATERTowards water sensitive cities:a three-pillar approachTony H. F. Wong, Cooperative Research Centre for Water Sensitive CitiesWhat is a water sensitive city? It is a city that interactswith the hydrological cycle to provide the water securityessential for sustained economic prosperity – byefficient and well-researched use of resources, including somethat have been overlooked by earlier generations of experts. Itis a city that enhances and protects the health of watercoursesand wetlands. It factors into all of its planning the risk oflooming drought and rising sea levels – and equally, the riskof sudden and unforeseeable floods. Such a city creates publicspaces that harvest, clean and recycle water. Its management ofwater contributes to biodiversity, carbon sequestration and thereduction of urban ‘heat islands’. A water sensitive city is onewhere water’s journey through the urban landscape is managedwith regard for its origins and its destinations – and where itsspiritual and cultural significance is celebrated. That city meetschallenges to the supply of life-giving water with integrity (notevasion), breadth of vision (not the expedient perspectives ofsectional interests), and evidence-based practice (not slogansfrom the past, nor borrowings from some imagined future).Our cities are water supply catchments – as illustrated by the Royal Park Wetland inMelbourne, used for harvesting and treating urban stormwaterImage: Tony H. F. WongWhat policies will yield these results? Three pillarsemerge to support such development – as affirmed byresearch at the Cooperative Research Centre for WaterSensitive Cities, an Australian Government initiative toforge partnerships between research institutions andindustry, to find solutions to global challenges. Thesethree pillars are overarching principles for meeting thechallenge of developing sustainable and resilient urbanwater systems:• cities as water-supply catchments• cities that provide ecosystem services• cities with the social and institutional capital forsustainability, resilience and liveability.Far from being abstractions or mere theoretical underpinnings,these pillars respond to a real need for realchange. They are eminently practical. We accept as agiven the energy and the bursting vitality of moderncities. That is not simply a part of the problem; it is alsoa significant part of the solution – so long as the threepillars are firmly established. And crucially, there areimplications for less developed cities.The first of our three pillars, cities as water-supplycatchments, stands in direct opposition to the traditionalmodel in which a city’s needs are passively servedby catchments external to it. Cities typically dependexclusively on the capture of rainfall run-off from ruralor forested catchments and/or on depleting groundwaterresources; but the evidence is that such a one-way transactionis far from optimal. It is certainly not sustainableas a universal solution. Communities become hostageto increasing temperatures and drying soils – problemsthat are all the more pressing because of ‘normal’climate variability, progressively worsened by thereality of long-term climate change. Reflex reliance onthe conventional approach (“just build another dam”)is no longer sufficient. The effects of climate changeare uncertain, and rainfall is not invariably reduced.But overall, it is established that global temperaturescontinue to trend higher. Drier catchments are nolonger a feature of one projected future among many;they are an inevitability. And drier catchments meandecreased run-off. Our precarious dependency on soilmoisture in external catchment areas has to be broken.This situation calls for a radically new model. Citiesthemselves have enormous potential as catchments,[ 275 ]