Increasing needs for new urban water infrastructure are very difficult to meet within existing environmental constraints. New ways must be found to deliver these services with lower water demand, greenhouse gas emissions, and discharge of nutrients. Alternative means of water servicing are being considered for long-term ecological sustainability. An environmental and economic assessment framework combined with various analysis tools like water balance, life-cycle costing, and life-cycle assessment (LCA) is presented in this paper to evaluate a range of alternative water servicing scenarios. LCA has the potential to evaluate development and associated service provision impacts on the environment in the long term, locally and globally. Application of this framework and analysis approaches was demonstrated on a 3062 hectare greenfield development for 86,000 residents near Melbourne.

Water authorities are faced with the ever present problem of expanding populations, sprawling urban developments and diminishing natural resources. Yarra Valley Water (YVW) the largest of Melbourne's three retail water companies is addressing the need to supply water and sewage services in the most environmentally sustainable way through the use of Life Cycle Assessment (LCA). LCA is an internationally recognised approach for comparing the environmental impacts of alternative products or services, and provides insights into the complexities and competing performance characteristics of alternative water and sewage servicing options. YVW has been using LCA in decision and policy support since 2002 and recently worked with RMIT Centre for Design and CSIRO Urban Water Group to undertake an LCA to consider alternative water and sewage servicing options of two developments sites.

This paper presents the results of a study from Brisbane, Australia where the relative merit of seven stormwater management design options that could be applied in typical, greenfield. medium density residential areas were assessed using a triple-bottom-line assessment framework. This framework involved assessing the financial, ecological and social dimensions of each option in consultation with stakeholders. The assessment process included the use of multi criteria analysis, a multidisciplinary expert panel, a local social survey of residents who live adjacent to alternative design options, two workshops involving typical citizens of Brisbane, consultation with traditional stakeholder groups, pollutant export modelling and water reuse modelling. The scope of issues investigated during the process was very broad. In addition, the information obtained from the community survey and public workshops is likely to be indicative of commonly held views of residents in cities similar to Brisbane. The multi criteria analysis stage of the assessment highlighted both large and small constructed wetlands as having the greatest overall net value compared to other options in the Brisbane region. However, the expert panel's preferred design option at the end of the process was bioretention systems located within the median strip of roads. Reasons for this discrepancy are explored.

The paper reports on a study by the authors which evaluates the energy and greenhouse impacts of different housing construction types across the building and occupation life cycle. Through comparison of the relative burdens of the embodied and operational (heating and cooling load) energy requirements of the different house construction types, the case is illustrated for incorporating life cycle aspects into housing environmental performance assessment. In the results presented, although mud brick performs well in embodied energy terms, it does not perform well overall compared to current conventional building configurations in Victoria. Analysis of the results is undertaken in order to illustrate the relationships between embodied energy, thermal mass and insulative properties of the key component building materials. The use of housing rating tools in Australia and the prospects for tool development incorporating LCA are considered. Possible future research directions are also considered, including modelling of plans with good passive design features and modelling a wide range of configurations.

What's better, centralised water and sewerage services, decentralised services, or a bit of both? This is the sort of question Yarra Valley Water (YVW) the largest of Melbourne's three retail water companies is currently grappling with as they focus their future planning efforts towards supplying new and existing dwellings with the most environmentally sustainable water and sewage services. This paper will look at the provision of water and sewage services to new and existing dwellings at three different sites, namely a greenfield development, an infill development and a backlog development. The results from the life cycle assessment (LCA), life cycle costing (LCC), water balance and water cycling modelling will be utilised to highlight the water cycling benefits associated with the provision of these services, the greenhouse gas emissions, the potential for nutrient and resource recovery, and the life cycle cost of each option to determine the economic cost of sustainable supply.