Sustainable cities are the dream. Reasonably self-reliant, the environmental impact of these metropolises are taken into account and the inhabitants do their bit to minimise the food, energy and water needed to live and to keep a city going. But how do we make that dream a reality? Who needs to be involved to bring sustainable cities to life? Dr Weisi Guo, Dr Frederik Dahlmann and Dr Phillip Johnstone, begin the discussion.

Dr Weisi Guo, School of Engineering. University of Warwick.

The ecology of cities is a hugely complex subject. In order to achieve sustainability, one must understand the mechanics of a city in quantifiable and rigorous ways. I think physical scientists have a proven track-record in measuring large volumes of data through intensive instrumentation. The knowledge will in turn provide the basis for urban science. This may be the dawn of a new scientific renaissance, but there are significant challenges related to instrumentation and challenging existing reasoning.

Dr Frederik Dahlmann, Warwick Business School. University of Warwick.

One of the key trends resulting from global population growth is the inexorable rise in urbanisation, which forces large cities to pay close attention to various sustainability issues involved in the provision of housing, food, and infrastructure.

This 'retro-fitting' of sustainability to existing cities is not without its challenges – a problem that many emerging cities can overcome if they incorporate sustainability principles already during their planning and growth phases. Regardless of size, however, one thing that all cities have in common is that their citizens need to be actively involved in making sustainable cities a reality.

Citizens provide the lifeblood and creativity to their urban surroundings. It is in their interest to vote, and provide mandates, for local politicians and mayors to consider sustainability in their decision making. One of the main reasons why people leave the countryside and move to the cities is the search for jobs and well-being. If these expectations are to be met and maintained, citizens need to understand the challenges involved in sustaining their urban ecosystems. Education and information are vital to ensure citizens have the knowledge and skills to demand and implement the necessary changes to their chosen habitat.

Dr Phill Johnstone, Centre for Water Sensitive Cities. Monash University

The short answer is everyone! However, focussing on urban water cycles, and their unsustainability, highlights some opportunities for real improvement.Urban areas extend their ‘water footprint’ by importing water and exploiting the ‘ecosystem services’ of other places to deal with their wastewaters (sewage and stormwater).

These impacts are exacerbated by structural inefficiencies in urban water cycles. In many cases the management of stormwater is rudimentary – disposing of it as a waste and concentrating on flood prevention. While this may meet some basic needs of cities, it appears to be oblivious to the hydrological effects of urban development. Impervious surfaces and hydraulically efficient drainage divert water from infiltration into the ground and evapotranspiration to the atmosphere, resulting in greater volumes and flows of stormwater.

However, the good news is that addressing these hydrological changes can reduce the water footprint of a city (by providing an alternative source of water and by reducing stormwater disposal) and, therefore, improve the city’s sustainability. Rather than treating stormwater as a waste to be disposed of, it can be thought of (and managed) as a part of the bio-physical processes of a city and a potential water resource.

Water Sensitive Urban Design (WSUD) (which includes the UK’s SUDS approaches to drainage) can, among other things, restore some of the natural hydrology and, through stormwater harvesting, provide a useful source of water.WSUD and SUDS are about redesigning and re-engineering urban drainage systems. So, who can do this? Water utilities tend to be focussed on the ‘taps and toilets’ of urban water cycles, while local (municipal) authorities build drainage infrastructure (including the ‘stormwater collectors’ of roads and footpaths). Collaborative efforts, involving water utilities (water resource management) and municipal councils (drainage, local infrastructure and amenity), utilising WSUD and SUDS, can deliver more sustainable urban water systems.

Sustainable Cities is one of the University of Warwick’s Global Research Priorities. The University is addressing global challenges through our world-class multi-disciplinary research.

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Published

May 2010

Dr Weisi Guo graduated from the University of Cambridge with MEng'05 MA'07 PhD'11. He is currently the joint coordinator of the Cities research theme at the School of Engineering. He has published over 40 peer-reviewed papers (12 Journals - total ISI impact factor: 23.4), 2 patents, and a book chapter by Cambridge University Press. He is the winner of EPSRC and University of Sheffield academic awards.

Dr Frederik Dahlmann joined Warwick Business School as Assistant Professor of Global Energy in October 2012. In his thesis Frederik investigated the longitudinal trends of corporate environmental strategy. He subsequently worked as an energy analyst in London.

Dr Phillip Johnstone is Adjunct Associate Professor (DSE Science-Policy Partnership), Centre for Water Sensitive Cities, Monash University, Australia.Dr Phillip Johnstone is Adjunct Associate Professor (DSE Science-Policy Partnership), Centre for Water Sensitive Cities, Monash University, Australia.
The University of Warwick and Monash University formed the Warwick-Monash Alliance in 2012.

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