Water Journal : Water Journal February 2013
WATER FEBRUARY 2013 33 Opinion Sydney has managed to add a million people to its population without increasing its total water use, through a combination of water ef ciency initiatives and a shift towards more compact housing. However, in the wake of signi cant drought, much of Australia's recent water security has been achieved with signi cant energy implication (Kenway et al., 2008; Victorian Water Industry Association, 2011) and there is much scope for the water sector to in uence energy use. For example, 13% of Australia's total electricity use, plus 18% of our natural gas use, is in uenced either directly or indirectly by urban water management in cities (Kenway et al., 2011). While approaches to achieving overall city ef ciency appear simple, they are complex, interconnected, confusing, value-laden and changing over time. They also involve multiple stakeholders. Consequently, in solving some problems, others are often created. The concepts and tools of urban metabolism can help us to assess and manage these kinds of risks as well as those related to supply chain disruption by natural or human-induced conditions. POTENTIAL FOR URBAN METABOLISM Over 100 years ago, the concept of urban metabolism was used to broadly understand all ows of matter between humans and the environment (Fischer-Kowalski, 1998). Today, we have reduced metabolism research to the point of understanding the internal workings of cells. In order to achieve ef cient cities by 2100, we believe the concept and application of urban metabolism could lead to aspirational, inspirational and unifying goals for cities and their multi-component water systems (Kenway, 2012). With all these advantages, why then has urban metabolism not been more widely adopted by water and energy utility managers? True, it has been proposed by academics as a framework for dealing with these interrelated issues for nearly 50 years (Wolman, 1965) yet direct translation of theory into practice has not yet begun. Why not? While some may argue that the theory of urban metabolism is too complex, this limitation is increasingly being overcome by better and more integrated data, clearer frameworks, improvements in methods and tools, and a progressive shift towards integrated governance models (for example, the progressive alignment of water and energy policy models). Our argument is that urban metabolism is a highly effective concept for understanding and managing the water, energy and materials ef ciency of cities and identifying where interventions are likely to generate the largest biophysical returns. This essay does not propose that urban metabolism theory is a grand universal theory that will solve all problems. The concept needs to be augmented with other concepts to support Australia's urban future: risk, resilience and cost-bene t analysis (Priestley, 2012). Over the last 100 years cities have largely overcome challenges using energy. However, when cheap fossil energy ends, our cities must adapt or decline. If we compare the systemic ef ciency of our cities with organisms, they are likely to be primitive and, hence, vulnerable. Cities that are water and energy self-reliant will increasingly supply themselves by achieving ef ciency and reuse from within. Urban metabolism is a valuable tool if we wish our cities to evolve toward more resilient and adaptable forms. We believe that in adopting an urban metabolism perspective and focusing on ef ciency, we will be more likely to create cities that are fabulous places to live. WJ THE AUTHORS Steven Kenway (email: firstname.lastname@example.org) is Senior Research Fellow, School of Chemical Engineering, University of Queensland. Francis Pamminger (email: Francis.Pamminger@yvw.com.au) is Manager, Research and Innovation at Yarra Valley Water. Paul Lant (email: email@example.com) is Head of School of Chemical Engineering, University of Queensland. REFERENCES Abal EG, Dennison WC & Green eld PF (2001): Managing the Brisbane River and Moreton Bay: An Integrated Research/Management Program to Reduce Impacts on an Australian Estuary. Water Science and Technology, 43(9), pp 57--70. ABC News (2007): Beattie Scraps Water Poll Amid 'Armageddon' Situation, Brisbane. Elkington J (1998): Cannibals with Forks: The Triple Bottom Line of 21st Century Business. Gabriola Island. New Society Publishers. Fischer-Kowalski M (1998): Society's Metabolism: The Intellectual History of Materials Flow Analysis, Part I, 1860--1970. Journal of Industrial Ecology, 2(1), pp 61--78. Kenway SJ, Priestley A, Cook S, Seo S, Inman M & Gregory A (2008): Energy Use in the Provision and Consumption of Urban Water in Australia and New Zealand. CSIRO and Water Services Association of Australia. Kenway SJ, Gregory A & McMahon J (2011): Urban Water Mass Balance Analysis. Journal of Industrial Ecology, 15(5), pp 693--706. Kenway SJ, Lant P & Priestley A (2011): Quantifying the Links Between Water and Energy in Cities. Journal of Water and Climate Change, 2(4), pp 247--259. Kenway SJ (2012): The Water-Energy Nexus and Urban Metabolism -- Identi cation, Interpretation and Quanti cation of the Connections in Cities, in School of Chemical Engineering, The University of Queensland, Brisbane, p 176. Newman PWG (1999): Sustainability and Cities: Extending the Metabolism Model. Landscape and Urban Planning, 44(4): pp 219--226. Pamminger F & Kenway SJ (2008): Urban Metabolism -- Improving the Sustainability of Urban Water Systems. Water Journal, 35(1), pp 28--29. Priestley T (2012): Towards Assessment Criteria for Water Sensitive Cities, In Technical Report No. 43, UWSR Alliance, Editor 2012, Urban Water Security Research Alliance, Brisbane. Wolman A (1965): The Metabolism of Cities. Scienti c American, 213, pp 179--190. Sahely HR, Dudding S & Kennedy CA (2003): Estimating the Urban Metabolism of Canadian Cities: Greater Toronto Area Case Study. Canadian Journal of Civil Engineering, 30(2), pp 468--483. Victorian Water Industry Association (2011): Electricity Issues in the Victorian Water Sector, Victorian Water Industry Association, Editor 2011, Victorian Water Industry Association, Melbourne. Wolman A (1965): : Energy and Material Flow Through the Urban Ecosystem. Annual Review of Energy and the Environment, 25, pp 685--740. Designing cities to be water- and energy-ef cient is a major future challenge for planners.
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