Abstract:
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.
