Triple-bottom-line assessment of water sensitive design options in a greenfield residential area

Abstract

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 multicriteria analysis, a multidisciplinary expert panel, a local social survey of residents who lived 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 multicriteria 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.