Australian Water Management Review Vol 2 2013 | Page 13

Stormwater treatment wetlands now used extensively in Adelaide to harvest and treat stormwater for non-potable uses

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ince the National Water Commission’s 2011 report on the future direction of urban water in Australia, the sector has intensified its strategising of its changing and future role across various fora. The Commission challenged the sector to “enhance its effective contribution to more liveable, sustainable and economically prosperous cities in circumstances where broader social, public health and environmental benefits and costs are clearly defined and assessed”. Therefore it will be necessary to for the water retailers to move beyond the traditional provision of ‘taps and toilets’ services of water supply and wastewater disposal to realise more multifunctional and flexible urban water systems delivering a broader range of services and outcomes for communities. Future urban water infrastructure will harvest and recycle an integrated mix of water sources (such as catchment water, stormwater, wastewater, greywater, seawater) bounded by principles such as minimising ecological footprints, through a more flexible combination of centralised and decentralised systems. It is this more complex systems approach that will enable a more sophisticated suite of social and ecosystem services such as water security, flood management, water quality protection of waterways, urban heat mitigation, enhanced biodiversity, amenity, social cohesion, catchment repair and overall improved system resilience – or coping capacity for future uncertainties. While this future is highly desirable, the scope of who (and what) benefits and loses from the qualitative changes to the status quo, with the critical task of determining - who pays and how? Historically, investment decisions have generally been based on water conceptualised

as an undifferentiated commodity. This has been underpinned by a reductionist economic valuation approach, with a small number of benefits and beneficiaries included for project viability assessments. Such valuations have been largely financial rather than economic and they have not served us well. This legacy has contributed to our current state of institutional and system fragmentation, ill-prepared to meet the challenges of sustainability and resilience in our urban water systems in the face of diminishing resources and environmental assimilative capacity. Responding to the critical water supply shortages and acute flood events during the last decade highlights the fundamental limitation of the traditional calculus of both value and risk across all levels of urban water infrastructure investment decision making. Critical to addressing this challenge is a clear acknowledgement and better understanding of the non-market costs and benefits (values) related to alternative approaches such as, decentralised stormwater harvesting, treatment and reuse and contingency planning activities. The concept that ‘our cities are water supply catchments’ - harnessing the full potential of wastewater and stormwater emanating from our cities to reduce their dependency on externally sourced water, including desalination of seawater -necessarily reframes what our water governance arrangements could look like. Given the system level dependencies, it is clear the water sector will not only need to deliver this in partnership with local government but also other sectoral agencies such as energy, transport, waste and health services. This is because solutions and infrastructure are going to be site and context specific, including the local social and political context, particularly in relation to the emerging significance of green infrastructure.

blueprint2013: Stormwater Management in a Water Sensitive Cities a recently published report documenting the many bio-physical benefits of stormwater green infrastructure [source: CRC for Water Sensitive Cities (2013) blueprint2013 – Stormwater Management in a Water Sensitive City. Melbourne, Australia: Cooperative Research Centre for Water Sensitive Cities, ISBN 978-1-921912-02-3, July 2013.]

There is increasing evidence that green infrastructure can deliver a net positive economic benefit to urban communities. ‘Our cities can provide ecosystem services’ through protecting and improving ecological values of urban environments and adjoining waterways by improving the quality of
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