Urban water systems: Drivers of climate change?

Abstract

Urban water systems contribute to climate change both directly through the fugitive greenhouse gas (GHG) emissions associated with water storage reservoirs and wastewater treatment processes, and indirectly through significant energy and materials consumption. This paper presents the findings of an investigation of the GHG emissions associated with operating a case study urban water system in Melbourne, Australia. It was revealed that the appliances associated with the residential end uses of water were responsible for significantly more GHG emissions than all upstream and downstream operations. These findings led to the conclusions that any project seeking to minimise the energy consumption and GHG emissions associated with urban water systems should: (a) consider the whole system, including the end uses of water, in a holistic application of life cycle thinking, and (b) focus on reducing the energy and water consumption associated with the end uses of water, since this will yield multiple benefits upstream, downstream and at the point of use.