Planning for sustainable urban water : systems-approaches and distributed strategies

University of Technology, Sydney. Institute for Sustainable Futures.This thesis develops and applies a number of methods for systems analysis and assessment within the field of sustainable urban water. These focus on the evaluation of distributed strategies. In line with arguments made within the thesis, the methods developed assess urban water on a whole-system basis, with the system defined in terms of the services provided. Further, the thesis argues for sustainable urban water planning to take a pluralist stance; both in the conception of sustainable urban water and the strategies considered. The challenges of sustainability and sustainable development are fundamentally problems of complex systems. Planning and assessment of sustainable urban water therefore require a systems-approach. Systems-thinking is not, however, a unified body of knowledge and this thesis develops a unique perspective on systems-thinking which is used to critically review the fields of sustainable urban water and its assessment. Within these reviews, the thesis develops a framework for understanding sustainable urban water in terms of a number of varied approaches, and describes a feasible theoretical basis for assessing sustainable urban water. Many, so called, sustainable strategies are small-scale and distributed in nature. Distributed strategies include decentralised systems, embedded technologies, and local measures for conservation. Traditional systems analysis methods have failed to account for distributed strategies. To adequately include distributed strategies, this thesis argues that assessment methods will need to be based on whole-system modelling, utilise end-use models of service provision, and include - in the form of a demand forecast - a time dimension in relation to service provision. This thesis proposes new methods for microbial risk assessment on a whole-system basis and Least cost planning for (urban water) Sustainable Scenarios (LeSS). A novel evaluation framework for least cost planning for water supply, which provides an equivalent comparison of demand- and supply-side options, is also developed. These methods are illustrated through case studies. These case studies illustrate the potential of distributed strategies. When assessed on an equivalent basis, in various examples, distributed strategies are shown to be particularly cost effective. Decentralised wastewater reuse systems are also shown to impose a theoretically lower level of pathogen risk on the community than equivalent centralised reuse schemes. Despite the advances in assessment methodologies made within the thesis, further development of practical tools for assessing and planning sustainable urban water remains an urgent goal