Water Sensitive Urban Design: Cost balance model through life cycle costing methods

Abstract

Water Sensitive Urban Design (WSUD) is a sustainable urban stormwater management method that enhances drainage water quality through ecological techniques. Despite its benefits, uptake has been slow as a set of barriers still prevents its wide-spread adoption (Lee et al. 2010). These barriers include a lack of information about water conservation policy implementations and costs practices (Yigitcanlar 2010). The project aims to bridge the financial knowledge gap by developing a “cost model” that determines the Life-Cycle-Cost (LCC) and probable water quality of diverse WSUD implementations within a specified catchment area. The model will place emphasis on maintenance activities as maintenance is considered to be amongst the highest cost drivers and is of particular interest to WSUD adopting organizations (Yigitcanlar 2010). The Armadale town council was able to provide actual costing data on their implemented urban water management system (WSUD design), in one of their residential areas, situated at Lot 50, Wright Road, Armadale. This site was used as the project study site as it had a wide variety of  implemented Best Management Practices (BMPs). This made it possible to incorporate the commonly practiced BMPs into the cost model. The Cost Model’s targeted BMPs are rain gardens, swales, wetlands, and infiltration basins which were all present at the site. With the acquired data, the LCC cost was determined by following the LCC costing procedure listed in the Australian Standard Life-Cycle-Costing Application Guide: AS IEC 60300.3.3 – 2005 (Australia Standard 2005). A selected discount rate of 5% used in the LCC calculation was assumed to be realistic in the Australian economic context (John 1997). The developed cost model has the benefit of being simple to use and it uses latest actual costing data obtained from a newly developed residential area to calculate LCC costing. The cost Model provides a stepping stone to making costing information available by determining costing from the maintenance plan perspective. This is likely to be useful during a decision making process.

Note: Journal articles and conference papers (and links where available) are available under open access arrangements where possible. Otherwise please contact your institution’s library, the authors, or publishers to organise full access.