Planning for sustainable urban water: Systems-approaches and distributed

strategies

Simon Anthony Fane

Institute for Sustainable Futures

University of Technology, Sydney

Thesis submitted for the PhD in Sustainable Futures

2005

i

Statement of original authorship

I certify that the work in this thesis has not previously been submitted for a degree nor

has it been submitted as part of requirements for a degree.

I also certify that the thesis is an original piece of research written by me, except where

noted in the text. Any help that I have received in my research work and the preparation

of the thesis itself has been acknowledged. In addition, I certify that all information

sources and literature used are indicated in the thesis.

Signature of candidate: Simon Anthony Fane

ii

This thesis is dedicated to love and hope:

Love of my partner Wendy and children Alexander and Madeline, and

Hope for a sustainable future.

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Acknowledgements

Whether I would have ever started on the journey that is presented in this thesis if it

were not for my father, is a question for a psycho-analyst; whether I would have

finished it without his advice, encouragement and editing is less in question. Thank you

dad for your counsel, your interest and your unending support.

Various people have worked with me on aspects of the research presented within this

thesis. I would like to acknowledge and thank my supervisor Professor Stuart White for

his support, intellectual input (particularly in relation to least cost planning) and his

continuing optimism. I would also like to acknowledge and thank my co-supervisor

Professor Nick Ashbolt from the University of New South Wales for his significant

contribution and guidance in relation to the part of the research that focused on the

assessment of waterborne disease risk.

The work of my colleagues at the Institute for Sustainable Futures must also be

acknowledged. In particular, the team who worked with me on the Sydney

Metropolitan Water Strategy project. The report from that project forms an Appendix to

this thesis. The efforts of Nicholas Edgerton for his endeavours on the final report and

Sally Campbell, Kate Beatty, and Meenakshi Jha for their labours in options modelling

need to be recognised here. I would also like to thank the NSW Department of

Infrastructure, Planning Natural Resources for allowing me to include the report.

Thanks also to my fellow postgraduate students at the Institute, including Chris

Reardon, Chris Riedy, Claire Gerson, Gabrielle Kuiper, Kumi Abeysuriya, Michelle

Zeibots and Wahidul Biswas for their thought provoking discussions, enthusiasm and

friendship at different times.

Financially, I must thank the Australian Research Council for the support of a post-

graduate award; Sydney Water Corporation for contributing a ‘top up’ stipend; the

Institute for Sustainable Futures for travel funds to various conferences; and the

MISTRA Urban Water Program for providing me with an airfare to Sweden.

Finally, to my friends and family, thank you for your love and encouragement

throughout the long journey.

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Table of Contents

Statement of original authorship………………………………………………………...i

Acknowledgements……………………………………………………………………..iii

Table of Contents……………………………………………………………………….vi

List of Tables.………………………………………………………………………….viii

List of Figures…………………………………………………………………………...ix

List of relevant publications……………………………………………………………..x

Abstract………………………………………………………………………..……….xii

1 General Introduction

1.1 Introduction……………………………………………………………………...1

1.2 Urban water and the challenge of sustainable development…………………….2

1.3 Research objectives……………………………………………………………...4

1.4 Content and structure……………………………………………………………5

1.5 The context of this work………………………………………………………...7

1.6 A readership beyond urban water……………………………………………….9

2 Sustainable development and sustainable urban water

2.1 Introduction…………………………………………………………………….10

2.2 Conventional approaches to urban water………………………………………11

2.3 Sustainable development……………………………………………………….14

2.4 Conceptualising sustainable urban water………………………………………18

2.4.1 Systems-thinking……………………………….………………………………19

2.4.2 Perspectives on the urban water system…….………………………………….21

2.4.3 Perspectives on the system-environment of urban water………………………23

2.4.4 Summary………………………………………………………………….........27

2.5 Approaches to sustainable urban water………………………………………...28

2.5.1 Water sensitive urban design…………………………………………………...28

2.5.2 Ecological sanitation……………………………………………………………32

2.5.3 Ecological Engineering…………………………………………………………36

2.5.4 Advanced treatment…………………………………………………………….39

2.5.5 The ‘soft path’ for water………………………………………………………..42

2.5.6 Summary………………………………………………………………………..46

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2.6 Synthesis and discussion……………………………………………………….47

2.6.1 Developing a pluralist stance…………………………………………………...47

2.6.2 Distributed strategies ………………………………………………………….49

2.6.3 Summary……………………………………………………………………….56

2.7 Conclusions…………………………………………………………………….56

3 Assessing sustainable urban water

3.1 Introduction…………………………………………………………………….59

3.2 A theoretical basis for assessing sustainable urban water……………………...60

3.2.1 System definition……………………………………………………………….60

3.2.2 System analyses and assessment……………………………………………….64

3.2.3 Uncertainty……………………………………………………………………..65

3.2.4 Summary………………………………………………………………………..67

3.3 Techniques available for assessing sustainable urban water…………………...67

3.3.1 Biophysical techniques…………………………………………………………68

3.3.2 Socio-economic techniques…………………………………………………….71

3.3.3 Multi-criteria integration techniques…………………………………………...76

3.3.4 Summary……………………………………………………….……….............82

3.4 A review of work to date assessing sustainable urban

water…………………...82

3.4.1 Introduction to an emerging field………………………………………………83

3.4.2 Assessments of biophysical criteria……………………………....…………….83

3.4.3 Socio-economic assessments…………………………………………………...90

3.4.4 Large group programs ……………………………………………………….....94

3.4.5 Summary………………………………………………………………………100

3.5 Identifying areas for further work…………………………………………….101

3.5.1 Whole system methods………………………………………………………..101

3.5.2 Accounting for distributed strategies in assessments…………………………103

3.5.3 Multi-criteria integration……………………………………………………...104

3.5.4 Managing subjectivity ………………………………………………………...107

3.5.5 Managing complexity…………………………………………………………108

3.5.6 Summary……………………………………………………………………....110

3.6 Conclusions…………………………………………………………………...110

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4 Whole-system microbial risk assessment

4.1 Introduction…………………………………………………………………...112

4.2 Waterborne pathogens, sustainable urban water and risk assessment………...113

4.3 The whole-system microbial risk assessment method outlined……………….116

4.3.1 Previous whole-system models in the food production sector...……...............116

4.3.2 Modelling framework…………………………………………………………117

4.3.3 Pathogen generation models…………………………………………………..118

4.3.4 System models………………………………………………………………...120

4.3.5 Hygiene impact model………………………………………………………...121

4.4 PAPER ONE: Life cycle microbial risk analysis of sustainable sanitation

alternatives……………………………………………………………………124

4.5 PAPER TWO: A methodology for assessing comparative pathogen impact from

novel wastewater recycling systems…………………………………………..133

4.6 PAPER THREE: Decentralized urban water reuse: The implications of system

scale for cost and pathogen risk………………………………………………140

4.7 Conclusions…………………………………………………………………...149

5 Equivalent assessment of demand- and supply-side options

5.1 Introduction…………………………………………………………………...151

5.2 Integrated resource planning, least cost planning and end-use modelling……152

5.2.1 Integrated resource planning………………………………………………….152

5.2.2 Least cost planning……………………………………………………………153

5.2.3 The role of least cost planning in integrated resource planning………………155

5.3 A review of currently used least-cost analysis methods………………………156

5.3.1 Calculating the avoided cost of water supply ………………………………...156

5.3.2 Calculating the cost-benefit of water conservation…………………………...159

5.3.3 Calculations of the levelised cost of water conservation……………………...159

5.3.4 Problems with the current least cost analysis methods………………………..162

5.4 PAPER FOUR: The Use of Levelised Cost in Comparing Supply and Demand

Side Options…………………………………………………………………...164

5.5 PAPER FIVE: Levelised cost, a general formula for calculations of unit cost in

integrated resource planning………………………………………………….173

5.6 REPORT ONE: Meeting Sydney’s Water Demand-Supply Balance………….182

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5.7 Conclusions…………………………………………………………………...183

6 Least cost planning for sustainable urban water

6.1 Introduction…………………………………………………………………...185

6.2 Backcasting, sustainability limits, externalities and cost analysis…………….186

6.2.1 Backcasting……………………………………………………………………186

6.2.2 Environmental economics, ecological economics, and externalities...………..187

6.2.3 A framework of externalities and constraints for urban water………………..189

6.3 The least cost sustainable scenario method……………………………….......190

6.3.1 Least cost scenario analysis…………………………………………...............191

6.3.2 Developing a framework of goals, constraints and externalities……...............192

6.3.3 A generalised methodology…………………………………………………...194

6.4 PAPER SIX: The secret life of water systems: Least cost planning beyond

demand management…………….……………………………………………196

6.5 PAPER SEVEN: What are the Implications of Distributed Wastewater

Management in Inner Sydney……………………………………………....…205

6.6 Conclusions…………………………………………………………………...212

7 Discussion and conclusions

7.1 Introduction…………………………………………………………………...214

7.2 Distributed strategies and sustainable urban water……………………………215

7.3 Pluralism and sustainable urban water………………………………………..217

7.4 Systems-approaches in the assessment of sustainable urban water…………...219

7.5 Service-defined systems analyses………………………………………….....223

7.6 Areas for further work………………………………………………………...225

7.6.1 Additional whole-system methods for sustainable urban water………………225

7.6.2 Further applications of whole-system microbial risk assessment…………….226

7.6.3 A framework for evaluation of demand- and supply-side options…...………227

7.6.4 Towards integrated planning for sustainable urban water…………………….227

7.7 Final conclusions……………………………………………………………...228

8 References………………………………………………………………..232-249

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List of Tables

Table 2.1 Approaches and strategies for sustainable urban water……………………...46

Table 2.1 A summary of potential sustainability issues for urban water……………....48 Table 3.1 Sustainability issues for urban water that might be addressed through MFA……………..…………………………………………………………….69 Table 3.2 Sustainability issues for urban water addressed by technical risk assessment……………………………………………………………………………...72 Table 3.3 Priority criteria and techniques from Hellstrom et al………………………..98 Table 3.4 Whole-system methods for assessing sustainable urban water…………….101

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List of Figures

Figure 2.1 Linear flows of nutrients water and contaminates induced by the conventional approaches to urban water……………………………………………….13

Figure 2.2 Social and ecological systems impose limits on the development of anthropogenic (human made) and economic systems………………………………….17

Figure 2.3 ‘Spheres of influence’ in the system-environment of urban water…………23 Figure 2.4 The local system-environment of urban water……………………………...24

Figure 2.5 Approaches to urban water and sustainable urban water…………………...28 Figure 2.6 A comparison of water sensitive and conventional drainage……………….29 Figure 2.7 The advantages of the Eco-San concept………………………………….…33

Figure 2.8 The Stensund wastewater aquaculture……………………………………...36 Figure 2.9 The ‘NEWater’ plant - wastewater treatment chain………………………...39

Figure 2.10 The end-use break down of water use in a household……………………..43

Figure 2.11 Diagrams of alternative urban water infrastructures………………………52 Figure 3.1 The spectrum of system definitions for urban water………………………..61

Figure 4.1 Whole-system microbial risk assessment modelling framework………….118 Figure 4.2 An example of a system model constructed of hygiene modifying units…121

Figure 5.1 Integrated resource planning: An iterative framework……………………155 Figure 5.2 A conservation supply curve from a study of water conservation

options for the Australian Capital Territory………………………………………..…160

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List of relevant publications

Papers included within this thesis:

Fane, S., Turner, A., and C. Mitchell, (2004) The Secret Life of Water Systems: Least Cost Planning Beyond Demand Management 2nd IWA Leading Edge Conference on Sustainability in Water Limited Environments, Sydney, November 2004.

Fane S., (2003), Life cycle microbial risk analysis of sustainable sanitation alternatives, Proceedings 2nd International Eco-San Symposium, conference, Lubeck, Germany, April 2003

Fane S, Robinson J., and S. White, (2003), The Use of Levelised Cost in Comparing Supply and Demand Side Options, Wat. Sci. Tech: Water Supply, Vol 3:3

Fane S., and S. White, (2003), Levelised cost, a general formula for calculations of unit cost in integrated resource planning, Proceedings Efficient 2003: Efficient Use and Management of Water for Urban Supply, Tenerife, Spain, April 2003

Fane S., Ashbolt N., and S. White, (2002), Decentralized urban water reuse: The implications of system scale for cost and pathogen risk, Wat Sci Tech, Vol 46:6

Fane S., and S. White, (2001), What are the Implications of Distributed Wastewater Management in Inner Sydney? Proceedings International Ecological Engineering Conference, Christchurch, New Zealand, November 2001

Fane S., and N. Ashbolt, (2000), A methodology for assessing comparative pathogen impact from novel wastewater recycling systems. Proceedings Water recycling, Adelaide, Australia, September 2000

Other relevant publications:

Fane A. and S. Fane, (2005), The Role of Membrane Technology in Sustainable Decentralized Wastewater Systems, Wat Sci Tech, Vol 51:10

Fane, S., Willetts, J., Abeysuriya, K., Mitchell, C., Etnier, C., and S. Johnstone, (2004), Evaluating reliability and life-cycle cost for decentralized wastewater within the context of asset management, Proceedings 6th Specialised Conference on Small Water & Wastewater Systems AND 1st International Conference on Onsite Wastewater Treatment & Recycling, Fremantle, Australia, February, 2004

Mitchell, C., Turner, A., Cordell, D., Fane, S. and S. White, (2004), Water conservation is dead: long live water conservation, 2nd IWA Leading Edge Conference on Sustainability in Water Limited Environments, Sydney, November 2004.

White S., and S. Fane, (2002), Designing Cost Effective Water Demand Management Programs in Australia, Wat Sci Tech Vol 46:6

Jha, M., Mouritz M., Smith P., and S. Fane, (2001), Integrated Water Management System in An Urban Redevelopment In Sydney, Proceedings International Ecological Engineering Conference, Christchurch, New Zealand, November 2001

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Malmqvist, P.A., Ashbolt N., Fane S., Hellstrom D., Jeppsson U, and H. Soderberg, 2000, Assessing Alternative Wastewater systems in Hammarby Sjostad Stockholm. Proceedings Decision support in Civil engineering, Lyon, France, November 2000

Fane, S., Ashbolt, N., and S. White, (1999), Incorporating waterborne pathogen data into decision support frameworks for evaluating sustainable sanitation options, Proceeding from the international ecological engineering conference, Aas, Norway. June 1999

Fane, S., Robinson, D. and S. White, (1998), Reduce, reuse or recycle? Economic evaluation of measures for improving environmental outcomes from wastewater systems, in: A.I. Schafer, L. Basson & BS Richards (eds), Environmental Engineering Research Event, Sydney: UNESCO Centre for Membrane Science & Technology, December, p. 363-8

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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

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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.

1

1 General Introduction

1.1 Introduction

This thesis addresses the general questions, ‘when planning sustainable urban water

infrastructures, what technologies and management practices are available, and how

should options be assessed?’ In addressing these questions, the thesis specifically

considers the issues that are raised by distributed technologies and practices.

As a general introduction to the thesis, this Chapter details the purpose and objectives of

the research. It also highlights those aspects of the work that can be considered novel

contributions to current knowledge on the assessment of sustainable urban water.

This Chapter introduces the topics of urban water and sustainability in section 1.2. In

section 1.3, the specific research objectives of the thesis are presented. The content and

structure of the thesis is detailed in section 1.4. The Chapter concludes by offering some

context to the research presented. In section 1.5, various interactions with other

researchers in the sustainable urban water field are detailed. The final section (1.6)

directs readers with an interest the assessment of urban infrastructures other than water

to points of relevance.

1.2 Urban water and the challenge of sustainable development

In this thesis, ‘urban water’ is understood to include water supply, wastewater and

stormwater for a city or town or a predominantly residential part there-of.

Urban water has historically been provided by large-scale centralised infrastructure

systems, which have been installed in the cities of industrialised countries over the past

150 years. These infrastructures, initially designed to protect public health and provide

fire safety, have been extremely successful in these respects (Harremoes 1999). The

resulting improvements in hygiene, security of property and availability of water supply

have allowed the growth of modern cities.

Despite their significant historic role, conventional approaches to urban water are

resource inefficient and increasingly expensive (Newman 2001). Demand for water is

seen to inevitably rise, and this increase must be met with more distant or more difficult

sources of supply. Rising expectations for both potable water quality and environmental

2

protection are met through increased levels of centralised treatment and extending

extraction/disposal pipelines. Such ‘supply side’ and ‘end of pipe’ thinking still

dominates many aspects of current application in urban water. However, change is

occurring. The realities of cost and limits to community acceptance of a continued

‘rationale of expansion’ mean that conventional approaches are seen as increasingly

impractical. New solutions are being sought as the concepts of sustainable development

are taken up in the urban water sector.

For water supply utilities looking to provide new services in regions where continued

expansion is no longer acceptable or feasible, Integrated Resource Planning (IRP) has

emerged as a way forward (Dziegielewski et al. 1993). Integrated resource planning is

an open, participatory, strategic planning process, emphasising least-cost analysis of

supply and conservation as means of meeting (water supply) service needs (Vickers

2001). The key principle is that supply-side and demand-side options are treated as

equivalent (Beecher 1996). In Australia, IRP and least cost planning (LCP) methods

based on end-use modelling are becoming accepted practice for a number of water

supply utilities, with significant funds being invested in water conservation by Sydney

Water Corporation in particular (Howe and White 1999). Despite this important shift

from ‘supply-side thinking’, IRP addresses only one facet of the challenge that

sustainable development will pose to conventional urban water.

The terms ‘sustainability’ and ‘sustainable development’ are now generally accepted in

the water industry and since the mid 1990’s these terms have been used in discussions

about the provision of urban water. The concepts of sustainability and sustainable

development broadly imply that whatever is done should not harm future generations

(Bell and Morse 1999). Also implied are more ‘holistic’ understandings and the

consideration of social, economic, and ecological aspects. Sustainable development is

often understood as the process or pathway towards sustainability (Harding 1998). The

term ‘sustainable development’ was popularised as a result of the ‘Our Common Future’

report by the World Commission on the Environment and Development (1987).

However, despite consensus around sustainable development as an objective, both

sustainability and sustainable development will remain contestable concepts

(Diesendorf 2000). There are hundreds if not thousands of definitions in publication.

3

Two more recent definitions, which have provided useful insights for this thesis, are

those of the New Zealand Parliamentary Commissioner for the Environment (NZ PCE

2000) and Diesendorf (2000). Writing about planning for urban water, the NZ PCE

highlights the point that “sustainable development is not a fixed state, but rather a

process of change” and further that this change process needs to be one “in which the

use of resources, technological development, and institutional change are managed so

as to meet future as well as present needs - while at all times not reducing the health

and life-supporting capacities of ecological systems”. As defined by Diesendorf

sustainable development comprises “types of economic and social development that

protect and enhance the natural environment and social equity”. This definition is

insightful because it is explicit about the ecological and equity aspects being primary,

and that sustainable development is a process in which an economy or society engages.

Considered holistically, urban water infrastructures are important points of interaction

between human settlements and ecological systems. Conventional urban water

infrastructures induce significant material flow through our cities (Beck et al. 1997;

Karrman 2001; Zessner and Lampert 2002) and our economy more generally (Newman

and Kenworthy 1999). Conventional approaches to urban water impact on aquatic

environments via bulk water take and the release of polluted effluents. Linear flows of

nutrients (such as phosphate) from agricultural land, through urban water infrastructures

to disposal, are not sustainable into the indefinite future (Otterpohl et al 1997). The

huge cost and physical resource requirements of continuing with the centralised urban

water infrastructures and conventional strategies are also drivers for more sustainable

approaches (Newman 2001). Further, the cost of this intensive resource usage by

conventional strategies is likely to increase as society moves down a path of sustainable

development.

A diverse range of less resource intensive strategies for urban water has been suggested.

Many of these ‘more sustainable’ technologies and management practices are small-

scale and localised in their nature and can be considered ‘distributed’. Such strategies

include: decentralised wastewater treatment and reuse, rain-tanks to capture roof water

for household use, increased water use efficiency, and the separation of wastewaters at

source to facilitate reuse. Because of their likely significant future role, this thesis places

emphasis on those issues raised by the assessment of options for sustainable urban water

by distributed strategies.

4

1.3 Research objectives

This thesis aims to: (i) review the field of sustainable urban water including the

technologies and management practices that are available, and (ii) develop methods that

will improve assessments of options for sustainable urban water. Specific consideration

is given to distributed strategies in relation to each of these goals. Further, it is argued

within the thesis that analysis that accounts for urban water infrastructures as whole

systems will be key to both the appropriate assessment of sustainable urban water and

the inclusion of distributed strategies in such assessments.

The research described within this thesis addresses the topics of sustainable urban water

and the assessment of options, as well as distributed strategies, and whole-system

methods for analysis of urban water infrastructure alternatives. The specific objectives

of the research are given below. These can be grouped in terms of literature review and

method-development. The two objectives of the literature review process are:

i. To provide a review and synthesis of the literature on, and concepts surrounding,

sustainable urban water, including a review of the various technologies and

management practices, which have been suggested for sustainable urban water.

ii. To critically review - with the goal of improving available assessment methods -

the theoretical basis for system analysis and assessment of options for sustainable

urban water, the existing analysis and assessment techniques, and the work to date

in the field.

From these reviews, three specific research objectives in relation to methods-

development emerge and are taken up within the thesis. These are:

iii. The development of a method that can assess the whole-system risk due to

microbial pathogens from novel distributed urban water options.

iv. To review and refine the LCP methods used in IRP with the aim of providing

equivalent analysis of bulk supply and distributed strategies (demand management

or local supplies) for providing water.

v. Building on LCP for water supply, to develop a LCP method for assessing

sustainable infrastructure scenarios with urban water treated as a single system

and to illustrate this method comparing distributed and centralised options.

5

1.4 Content and structure

The thesis is divided into seven chapters: Chapters two to six address objectives i) to v)

respectively. Chapter seven draws together conclusions in relation to distributed

strategies for urban water, and systems analysis and assessment of sustainable urban

water infrastructures more generally.

Chapter two, Sustainable development and sustainable urban water, is a review of the

literature, describing the concepts, perspectives, technologies and management practices

which can be grouped as sustainable urban water. Due to the universal appeal of the

descriptor ‘sustainable’, literature in this area has recently burgeoned, and opinion

varies on what constitutes sustainable urban water. The review utilises both systems-

thinking and the notion of ‘an approach’ (which links perspectives on sustainable urban

water to strategies) as means of synthesis. This allows for a cogent discussion of a broad

topic area. From the review, the concept of distributed strategies and the need for a

pluralist stance when planning sustainable urban water emerge as important ideas.

Chapter three, Assessing sustainable urban water, develops a theoretical basis for the

assessment of options for sustainable urban water, as well as exploring the existing

analysis and assessment techniques and critically reviewing the work to date in the field.

The Chapter argues that the assessment of options for sustainable urban water should be

based on analysis of whole-system models. Whole-system is understood to mean that at

least, a water supply, stormwater, or wastewater infrastructure is treated as a complete

system. Assessments based on integrated system definitions where supply, stormwater,

and wastewater are considered together, as a single entity, are also included. Likewise,

assessments that consider urban water infrastructures as a component of a larger system

are also considered to be whole-system based. A critique of the field identifies gaps and

opportunities for further work. This then provides the context for the method-

development presented in the subsequent chapters.

Chapter four, Whole-system microbial risk assessment, presents a method for assessing

the relative impact of waterborne pathogens from proposed novel infrastructure

configurations. Sustainable urban water infrastructures inevitably involve some reuse of

effluents and/or other sewage components. Such reuse carries inherent risks from

waterborne pathogens. The methodology developed is applied to questions of local

effluent reuse in three papers. In Paper one, ‘Life cycle microbial risk analysis of

6

sustainable sanitation alternatives’, two infrastructure scenarios of equivalent cost, each

recycling treated sewage back to residences as secondary non-potable supplies, are

compared. In one option for this hypothetical development, composting toilets are

installed. This means that faecal wastes are managed separately from the recycled

greywater. In the other scenario, all sewage is combined, treated and recycled. In Paper

two, ‘A methodology for assessing comparative pathogen impact from novel wastewater

recycling systems’, blackwater and greywater non-potable recycling are again

compared. In this example, the same effluent treatment was assumed for each system

and the impact of process unit reliability was investigated. The third paper, Paper three

‘Decentralized urban water reuse: The implications of system scale for cost and

pathogen risk’, includes an example which examines the theoretical relationship

between the scale of reuse infrastructures and the waterborne infection risk.

Chapter five, Equivalent assessment of demand- and supply-side options reviews the

current methods suggested for assessment and analysis of water conservation, demand-

side and other options within the IRP literature. The Chapter incorporates two papers

and an introduction to a report. Paper four, is titled ‘The Use of Levelised Cost in

Comparing Supply and Demand Side Options’ and incorporates a hypothetical example,

showing the inconsistency in conventional analysis between demand management,

localised secondary supply and bulk supply augmentation. It is followed by Paper five,

‘Levelised cost, a general formula for calculations of unit cost in integrated resource

planning’, which refines the LCP methodology and focuses on how levelised unit cost

can be used in option ranking and scenario development. The improved method treats

demand-side and supply-side options equivalently and considers the provision of water

supply services holistically in the form of demand-supply scenarios. The method is

further refined and applied within a Report titled ‘Meeting Sydney’s Water Demand-

Supply Balance: An evaluation of demand and supply side options for the NSW

Government Plan – Securing water for our people and rivers’. This report was a key

input to the Sydney Metropolitan Water Stratergy, a 25-year water supply plan for

Sydney. The report was prepared for an interagency taskforce set up for the New South

Wales State Government to develop the plan. The project involved development of a

tailored qualitative and quantitative evaluation framework for demand- and supply-side

options and scenarios for Sydney as well as modelling and evaluate of options and

7

scenarios. The author of this thesis was the principal author of the framework and the

report. The full report is found in an Appendix to this thesis.

Chapter six, Least cost planning for sustainable urban water, develops water supply

LCP methods for the assessment of sustainable infrastructure scenarios covering all of

urban water. Unlike existing forms of life cycle costing, in line with water supply LCP,

the least cost planning for sustainable scenarios method (LeSS) is based on a projected

demand for the water services to be provided. This means that distributed and

centralised strategies are treated in an equivalent way in the options analysis. A

framework is also developed which incorporates the qualitative aspect of sustainability

with the quantitative analysis of costs. Parallels can be drawn with Energy Backcasting,

a method described by Robinson in 1982. The LeSS method however differs from

Robinson’s method in that sustainability is addressed explicitly (and it is applied to

urban water). Two papers illustrate the method. Paper 6 is titled ‘The secret life of water

systems: Least cost planning beyond demand management’. This paper contains an

example of the LeSS method applied in constructing and comparing various scenarios

for sustainable urban water for a new development area in the outer Melbourne. In

Paper seven, ‘What are the Implications of Distributed Wastewater Management in

Inner Sydney?’ scenarios for the future urban water infrastructure in Inner-Sydney are

compared. Included is a transformation scenario from the existing system to a system

incorporating distributed wastewater treatment and reuse.

The conclusions drawn in Chapter seven relate to four themes. In planning for

sustainable urban water infrastructures, a pluralist stance is required and the potential of

distributed strategies in providing urban water services needs to be considered. When

assessing the options available, assessment should take a systems-approach and apply

whole-system analysis methods. These four themes emerge from the thesis in answer to

the general questions posed at the beginning of Chapter one.

1.5 The context of this work

The research presented in this thesis was conducted at a unique academic institution and

within emerging fields of study. The content of the thesis is in large part a result of the

substantial progress in research on the assessment of sustainable urban water that has

occurred over the period of candidature. Interactions with key researchers in the field

are detailed below.

8

The character of the thesis reflects the unique influence of the research environment that

exists at the Institute for Sustainable Futures (ISF) at the University of Technology,

Sydney. The Institute is transdisciplinary and was established in 1996 to work with

industry, government and the community to develop sustainable futures through

research, constancy and learning. Regular discussions with colleagues at ISF, and

particularly the other PhD students in ‘sustainable futures’ have been critical to the

thoughts developed in this thesis.

In addition, ISF is known in Australia and internationally for its work on end-use based

demand modelling, demand management and LCP in the water industry. Method-

development within the thesis has naturally drawn on this experience and likewise

research conducted for the thesis has influenced the Institute's work in this area.

During the period of candidature two significant research programmes have been

developed with the aim of developing multi-dimensional, whole-system methods to the

analysis and assessment of urban water infrastructures. The Swedish MISTRA research

programme Sustainable Urban Water Management started in 1998 and aims at

developing and assessing sustainable solutions for water supply and wastewater

(Malmqvist et al. 2000). Interaction with the MISTRA programme involved

collaboration with the programme’s systems analysis group during two visits to

Sweden. The microbial risk assessment methodology presented in Chapter four was

developed within the context of the suite of assessment methods developed by the

MISTRA programme.

The Australian CSIRO has also established an Urban Water Program in 1998. The

program saw a number of CSIRO scientists from different divisions come together to

develop systems analyses of alternative urban water infrastructures (Speers 2000).

Contact with the CSIRO program has been ongoing and involved access to their reports

and results.

Participation in Australian and international conferences has played a part in shaping

this thesis. This is reflected in a number of published conference papers being included

within the body of the thesis. During the course of this thesis, papers were presented at

the International Ecological Engineering conferences at Aas in 1999 and Christchurch

in 2001. Papers were also presented at the International Water Association World Water

9

Congresses, both in Berlin in 2001 and in Melbourne in 2002. Components of this thesis

were also presented to the Water Reuse 2000 symposium in Adelaide, the Efficient

2003 conference in Tenerife, at the 2nd International Symposium on Ecological

Sanitation in Lubeck 2003 and most recently at the International Water Association’s

Leading Edge Conference on Sustainability, Sydney, in November 2004.

Visits to research groups at Imperial College in London, the Agriculture University of

Upsalla, Chalmers University of Technology in Gotheburg, and International Institute

for Industrial Environmental Economics at the University of Lund also proved fruitful.

1.6 A readership beyond urban water

Despite being focused on urban water, this thesis has been influenced by previous work

on other utility infrastructure systems, in particular IRP for energy supply planning. The

thesis may in turn inform infrastructure planning in other sectors. A readership beyond

urban water is hoped for, and therefore anticipated. Potential readers may have interest

in systems analysis and sustainability assessment and/or the construction of sustainable

development scenarios for urban infrastructures. The work presented in Chapters two

and three on sustainable development, systems and assessment should be of interest.

The methods developed in Chapters five and six also have potential for application

beyond urban water. Chapter five describes a method that has direct application for all

utility supplies, whether these are electricity, gas or water. With significant further

development, the LeSS method described in Chapter six could also be adapted to urban

infrastructure beyond water, including energy supplies, solid waste management and

even urban transport infrastructures.

10

2 Sustainable development and sustainable urban water

2.1 Introduction

Since the late 1980’s, an extraordinary amount has been written about ‘sustainability’

and ‘sustainable development’. As with other sectors, organisations such as water

utilities have sought to understand how these concepts impact on their operations.

Various research groups have worked towards rethinking the provision of urban water

in terms of sustainability and many technologists have reinterpreted their work on water

supply, stormwater, and wastewater in terms of sustainable development. As a result,

the literature on sustainable urban water has burgeoned. Accepting the limitations of

such a broad topic, the goals of this chapter are to: provide a background on urban water

and sustainability, and produce some synthesis of the sustainable urban water literature.

A comprehensive review of sustainable development is beyond the scope of this thesis.

Instead, this chapter outlines its historical background and argues for a position of

pluralism (accepting a multiplicity of understandings within limits of reasonableness) in

relation to sustainable development.

The conception of sustainable urban water is initially discussed in the context of

systems-thinking. The notion of ‘an approach’ is then introduced. This provides a means

of synthesis, linking the various perspectives on sustainable urban water found in the

literature to the strategies (technologies and management practices) these perspectives

support. The review seeks to cover the range of perspectives that can exist in relation to

sustainable urban water as well as the technologies and management practices currently

suggested within the literature.

The chapter opens with section 2.2 describing conventional approaches to urban water

and section 2.3 providing a background to sustainable development. Section 2.4

introduces systems concepts and utilises these to discuss urban water and sustainability.

Section 2.5 reviews sustainable urban water in terms of varying ‘approaches’. Section

2.6 develops the notion of ‘distributed strategies’, a concept applicable across

approaches. The conclusions drawn in section 2.7 include the contention that planning

for sustainable infrastructures requires a pluralist and systems-based understanding of

urban water, and that there is a need to account for distributed strategies.

11

2.2 Conventional approaches to urban water

Conventional urban water supply, stormwater and wastewater infrastructures are based

on large-scale centralised pipe networks. Potable water and sewage treatment plants are

also large. These conventional approaches to urban water infrastructures were

developed in the 19th century. They were installed in the industrial cities of that age to

improve chronically poor hygienic conditions and to circumvent cholera epidemics and

fire in densely populated urban areas. Towards the ends of public health and safety,

centralised urban water infrastructures have been extremely successful (Harremoes,

1999). Conventional approaches continue to ensure hygiene and provide sanitation,

flood and fire control as well as water supply to developed urban areas across the globe.

In the sprawling urban form of cities and urban areas built since World War II,

conventional approaches to urban water are now, pushing the limits of practicality and

bearable cost (Newman, 2000). It is also not clear whether conventional centralised

infrastructures can be made sustainable at any cost (Larsen Gujer, 1997).

Traditionally, providing urban water has not been a singular concern. Conventional

approaches have considered water supply, stormwater and sewage infrastructures in

isolation. In Australia, sewage and stormwater infrastructures are deliberately separate

(at least in theory) and are therefore commonly considered independently. Strategic

planning, construction, and management for each infrastructure are conducted more or

less autonomously, often by different organisations. In instances when water supply,

sewage or stormwater have been considered together, this has been in terms of the

negative impacts of one infrastructure on the another, such as the issues caused by cross

connection or leakage-infiltration between adjacent pipe networks.

The conventional approach to providing urban water supply is a large-scale reticulation

network supplying bulk volumes of potable water sourced from outside the urban

region. Demand for water was seen to inevitably increase and this demand had to be met

by tapping new bulk sources of supply. Rising expectations for potable water quality are

met with more advanced (centralised) water treatment technologies. In most cases, all

water supplied is of the same potable quality, regardless of use. Historically use of water

by consumers was often not measured and consumers have been charged a flat rate or

property tax for connection to the potable supply. Challenges to this conventional

12

approach have arisen as access to affordable new sources becomes increasingly difficult

and costly. Access is often restricted, as more-distant water resources need to be tapped.

It is now common for water resources to be fully committed to local communities and

environments. Technical solutions such as desalination or potable reuse are seen as

possible ‘limitless’ sources of supply. However, as discussed in section 2.5.1, while

technically feasible such advanced treatment strategies are relatively expensive and

resource intensive forms of water supply.

The conventional approach to providing sanitation and wastewater in Australia is a

large-scale gravity sewer network with centralised sewage treatment. Effluent is

disposed of to local receiving waters, the ocean or to land. Expectations of better

environmental quality in receiving waters are met via increased levels of sewage

treatment (Niemczynowicz, 1992) or in cities like Sydney with deeper, extended ocean

outfalls. A critical issue for conventional sewers is the infiltration of stormwater leading

to overflows. In conventional sewage infrastructures, this problem is extremely difficult

to solve. Even with a significant investment, only a marginal decrease in sewer

overflow frequencies and magnitudes is achievable.

Conventional stormwater management has focused on providing adequate drainage to

avoid flooding. These stormwater infrastructures rely on concrete pipes and channels to

move rainfall out of urban areas as quickly as possible. End of pipe treatment is difficult

as conventional infrastructures produce intermittent large volume flows at the point of

outlet. Without treatment, contaminants that have been washed into stormwater then

pollute receiving waters. As with conventional approaches to water supply and sewage,

conventional stormwater is becoming an increasingly expensive, inefficient and an often

impractical means of achieving community expectations for environmental quality.

A looming challenge for the conventional approaches is the massive replacement costs

for the existing infrastructure. Aging water supply, stormwater and wastewater

infrastructures and escalating repair and replacement cost are emerging as significant

issues for Governments around the world (NZ PCE, 2000; US Senate, 2001; Australian

Senate, 2001; NSW Legislative Assembly 2002). The cost of maintaining existing

infrastructures at current levels of service is likely to increase markedly in the next few

decades (AWWA, 2001). Maintenance and renewal of deteriorating centralised urban

13

water infrastructure remains a significantly under addressed issue in urban areas

throughout the world.

Faced with extraordinary needs for investment to renovate existing infrastructures,

sustainable development represents an even more fundamental challenge for planners

and managers of urban water. Many authors (including Beck et al. 1997;

Niemczynowicz, 1993; and Newman and Kenworthy, 1999) have pointed to the

significant and unsustainable material flows, which are induced by conventional urban

water infrastructures. In particular, the linear flow of nutrients from agricultural lands

cannot be sustained indefinitely (Otterpohl et al., 1997; Esrey 2000). Figure 2.1

illustrates the shortcomings of conventional urban water systems in terms of material

flows. Existing challenges such as the limits to water resources for supply and the

removal of pollutants from sewage effluents and urban run-off are cast in a different

light by considering them as symptoms of linear flows. Conventional approaches are

therefore likely to provide expensive, resource intensive and partial solutions to these

problems (Niemczynowicz, 1993).

Figure 2.1 Linear flows of nutrients water and contaminates induced by the

conventional approaches to urban water (from GTZ Ecosan, 2003)

14

Material flows, resource use and economic cost are broad concerns. Even so, as outlined

in the following sections, sustainable development and sustainable urban water

encompass further aspects and must be considered even more holistically.

2.3 Sustainable development

Sustainable development is a widely accepted concept, which implies, in a general

sense, that actions undertaken now should not harm future generations (Bell and Morse,

1999). It is holistic in nature in that it links concerns for environmental degradation to

the issues of development. Many of the ideas central to sustainable development were

previously discussed in other terms. Earlier concepts include ‘natural capital’, ‘limits to

growth’ and ‘environmental conservation’.

Schumacher in 1974 was one of the first authors to highlight the dilemmas of natural

capital. The problem was that industrialised societies were (and are) following

development paths that liquidated natural capital and treated this exhaustion of capital

as if it were income (Schumacher, 1974). Schumacher specified three categories of

natural capital being treated in this way. These were: fossil fuels; ‘the tolerance margins

of nature’; and ‘human substance’ (social and individual values). The concept of natural

capital for Schumacher thereby linked development to concerns for non-renewable

resource use, ecological destruction and issues of social cohesion (now understood in

terms of equity, social justice and social capital).

The ‘Limits to growth’ report (Meadows et al., 1972) to the Club of Rome took a

systems-approach (see section 2.4 below) to the issues of environmental degradation,

resource usage, population and development. Using at the time powerful computer

modelling, the researchers predicted the collapse of global social and economic systems

within a century if dramatic changes to development patterns did not occur. Exponential

growth in population and industrial output would drive the collapse. Limits would be

reached in the availability of non-renewable and renewable resources. The report

concluded that with appropriate changes, conditions of ecological and socio-economic

stability could be reached and sustained into the future. At the time, the report sparked

wide-ranging debate on development pathways and population control.

At an international level, many of the ideas and principles now considered ‘sustainable

development’ were first presented during the Stockholm United Nations (UN)

15

Conference on the Human Environment in 1972 and set out in the World Conservation

Strategy (UNEP, 1980). This strategy was produced by the International Union for

Conservation of Nature and Natural Resources in collaboration with the UN

Environment Program and other groups. Circulated to all national governments this

report defined conservation as: “The management of human use of the biosphere so that

it may yield the greatest sustainable benefit to present generations while maintaining its

potential to meet the needs and aspirations of future generations.”

The World Conservation Strategy argued that the difference between sustainable

development and traditional development was that while both used the biosphere for

human ends, the former considered future generations through including conservation.

A key theme of the report was that economic activities could and must be attuned with

environmental protection and more appropriate use of the earth’s resources (Beder,

1993). The strategy also emphasised that development must be within the carrying

capacity of supporting ecosystems and that ecological processes, individual species and

genetic diversity need to be preserved (Bennett, 2001). The World Conservation

Strategy highlighted three key tenets for sustainability: the long term; the ongoing

requirement to meet human ‘needs’; and ecological limits to human activity.

Sustainable development was brought to the fore in the report titled ‘Our Common

Future’, by the World Commission on the Environment (1987). In the Brundtland report

(as it is known), sustainable development is defined as: “development that meets the

needs of the present without compromising the ability of future generations to meet their

own needs.” In the context of the Brundtland report ‘needs’ were seen to include a

sound environment, a just society and a healthy economy (Diesendorf, 2000). As a

result of the Brundtland report, the UN General Assembly and a majority of national

Governments accepted the goal of sustainable development.

In Australia in the early 1990’s, the Commonwealth Government undertook a major

review of the issues and policy options to promote sustainable development (Beder,

1993). Ecologically Sustainable Development or ESD process as it was known,

involved State and Commonwealth Governments, industry bodies and conservation

organisation in a number of working groups across nine industry sectors (Bennett 2001).

Despite the working groups making over 500 recommendations to Government, (Beder,

1993) there was dissatisfaction from conservationists with many of the outcomes.

16

Consensus processes saw contentious issues dropped rather than addressed and

recommendations watered down (Harding, 1998). Vested interest in industry,

particularly the fossil fuel and resource sectors came to dominate a number of the key

working groups (Diesendorf and Hamilton, 1997). As the Government’s position on

sustainable development emerged through the process, to many conservationists and

other environmentalists it seemed to be pro-development with sustainability as an add-

on. There was an implicit assumption that economic growth would continue and that

environmental concerns could be accommodated with some improved regulatory

mechanisms and better valuation techniques (Harding, 1998). To environmentalists and

critics in the conservation movement such a stance ignored what they saw as the central

issues, which were conserving biological diversity and ecological integrity in the face of

irreversible human impact.

The dissatisfaction with the ESD process in Australia illustrates key characteristics of

sustainable development. Firstly, it demonstrates that despite consensus around

sustainability as a goal, the concepts of sustainability and sustainable development are

and will remain contested (Diesendorf 2000). Secondly, it illustrated that different

definitions of sustainability and sustainable development imply different and changed

power relationships in society. Self interested promotion of particular definitions and

ideological orientation by individuals and organisation must be expected.

Sustainable development is contextual and is inherently values laden. What is perceived

as sustainable development will depend on the temporal, spatial and cultural context as

well as world-view. World-views will vary with knowledge, ideological orientation and

values more generally. This, together with the irresolvable uncertainty, which is innate

within the nature of complex system dynamics (Kay et al., 1999) mean varying

positions on sustainable development can be rationalised and defended. Diesendorf

(2000) nevertheless asserts the value of sustainability and sustainable development as

useful concepts and argues that debate and discussion about their meanings are in fact

part of the practical process of working towards sustainability.

Multiplicity of perspectives is then an important feature of sustainable development.

This does not however mean that all definitions of sustainable development should be

accepted. This thesis argues that, despite a need to accept multiple positions on

sustainable development, the existence of positions promoted by the self-interest and

17

ideologies mean that a basic minimum criteria of ‘reasonableness’ needs to be set. This

is a pluralist stance on sustainable development; pluralism meaning the acceptance of a

multiplicity of positions within limits set by reasonableness (Isaiah Berlin, 1998).

This thesis argues that any reasonable definition of sustainable development must

recognise the primacy of ecological constraints over development aspirations. Human

activity (economic or otherwise) cannot be sustainable if stocks of critical natural

capital are depleted. We must operate within the limits of tolerance of ecological

systems, which are performing essential life support functions. In other words,

conserving biodiversity and the ecological integrity must be an absolute constraint on

the sustainable development process.

Further, in the face of potentially catastrophic outcomes, the only reasonable response is

precaution and therefore the ‘precautionary principle’ must be accepted. The

precautionary principle is commonly cited in relation to sustainable development

(Beder, 1993). This principle applies to cases of uncertainty about cause and effect, or

the level of effect, which would cause significant environmental impact (Harding,

1998). The precautionary principle implies that uncertainty should not be used as a

reason to prevent action that could mitigate serious harm to the environment.

The idea, that there are fundamental limits to the possibilities for sustainable

development, is illustrated in figure 2.2 below.

Figure 2.2 Social and ecological systems impose limits on the development of

anthropogenic (human made) and economic systems.

Economic

system

Anthropogenic

system Economic

system

Anthropogenic

system

18

A reasonable definition of sustainable development must also recognise fundamental

social limits to development. The social aspects of sustainable development are

commonly discussed in terms of the principles of intragenerational and intergenerational

equity (Beder, 1993). However, it is important that these principles are seen as more

than goals to be obtained in the future. In the same way that many ecological constraints

apply to the on-going process of sustainable development, there will be continuing

limits of tolerance for inequity and injustice within social systems.

2.4 Conceptualising sustainable urban water

Concepts like ‘sustainability’, ‘sustainable development’, and ‘sustainable urban water’

are multifaceted, and perspectives on them will vary. Despite this, a common linkage is

an intrinsic basis in ‘systems-thinking’. Whichever perspective is taken, to make sense

of such abstract concepts requires the definition of the system(s) to be sustained. This

section therefore utilises systems-thinking as a means of outlining some of the potential

range of perspectives on sustainable urban water.

Generally speaking, systems-thinking is about the study of entities as wholes within an

environment and may involve a hierarchical conception of systems being part of other

systems. Systems-thinking requires abstraction, as a collection of objects or elements

will be defined as a singular entity or system. Applying systems-thinking to sustainable

urban water, urban water can be understood as a whole and an urban water system’s

sustainability can be understood in terms of that system’s relationships within a

hierarchy of local, regional and global systems. Alternative perspectives on sustainable

urban water are then understood to be alternative definitions of the urban water system

and its system-environment.

In this thesis, the term ‘systems-understanding’ is used to refer to an understanding

based in systems-thinking. A systems-understanding means that comprehension of a

given phenomenon or object is constructed in terms of systems, their functions, and

interactions with other systems. A ‘systems-approach’ is then any method or process

applying this type of understanding and will involve the explicit definition of systems,

their boundaries and system-environments.

This section initially discusses systems-thinking before examining possible perspectives

on urban water systems and their system-environments in the context of sustainability.

19

As well as providing an insight into alternative perspectives on sustainable urban water,

systems-thinking forms the basis of the review of analysis and assessment methods in

Chapter three and the method-development in Chapters four, five and six.

2.4.1 Systems-thinking

At a general level, systems-thinking is a way of considering phenomena or objects as

wholes (Emery 1969). Systems-thinking is not however a unified body of knowledge

and lacks consensus on definitions even for key terms like ‘system’ and ‘system

boundary’ (Kay and Foster 1999). There is then no single form, which constitutes

systems thinking or a systems-approach, but there are various traditions that share some

concepts and practices.

This thesis therefore takes a stance on systems-thinking that is in accord with the aims

of reviewing the field of sustainable urban water and developing methods to assess

these infrastructures. It is a form of systems thinking, which is by its nature

transdisciplinary. As Meadows (2001) argues, to understand a given system, knowledge

from various studies in different disciplines needs to be brought together and integrated.

Systems-thinking involves synthesising all the relevant information that we have about

a phenomenon or object so we have a sense of it as a whole (Kay and Foster 1999).

Holism is a key tenet of systems-thinking that embodies the idea that an object or

phenomena can only be fully understood in its entirety, as a whole, and that to break it

down into pieces risks missing critical characteristics (Bell and Morse 1999). Together

with wholeness, the other key characteristics of systems are that they commonly exhibit

hierarchy, are inherently subjective and have the potential for complexity.

Systems-thinking involves a hierarchical understanding of systems within systems (Kay

and Foster 1999). To gain a whole understanding of a system may mean either

considering that system as being formed by component systems, or the system as being

embedded within a larger system. The potential for developing a hierarchical

understanding applies both inwards and outwards. Systems-thinking is then

fundamentally different from more conventional ‘scientific-thinking’ as conventional

scientific understandings and methods are reductionist while systems-thinking

incorporates reductionist understandings but is holistic (Bell and Morse 1999).

20

Developments in the study of complex systems mean that it is important to

acknowledge the potential adaptive, self-organising and emergent characteristics within

and between systems when complexity exists (Kay et al. 1999). Complexity arises when

there are multiple interrelationships and feedback loops. Complex systems are

intrinsically uncertain and the possibility of predicting the behaviour of such systems is

correspondingly limited.

Kay et al. (1999) assert that the challenge of sustainability is fundamentally a systems

problem and that it will inevitably involve complex systems. Agreeing with Kay et al.,

this thesis defines a sustainable system as one which maintains vital functions while

interacting with critical systems in its system-environment in a manner that allows their

functions to be maintained. Sustainability can be understood in terms of either the

systems or the relationships between systems. However, because of complexity, it may

not be possible to identify with certainty what the vital functions and relationships are

and over what timeframe maintenance must occur.

Although not universally accepted, in this thesis it is understood that systems are

inherently subjective. Any system is dependent on an observer or group of observers for

implicit or explicit definition. As Senge et al. (1994) states “a system is a perceived

whole whose elements ’hang together’ because they continually affect each other over

time and operate towards a common purpose…the structure of a system includes the

quality of perception, with which you the observer cause it to stand together” (cited

from Bell and Morse 1999). The ‘quality of perception’ described by Senge et al. (1994)

in relation to a system applies equally to the system-environment.

To utilise systems-thinking in analysis or assessment (to apply a systems-approach), a

system and its boundary and system-environment must be defined. Defining a system

involves determination of its constituents and functions. Defining a system’s

environment includes identifying the other systems with which the principal system is

seen to interact. Defining a system-environment also involves identifying the system

boundary, as a finite system must be delineated from its environment. For an open

system, interactions will exist between it and its environment. Constituents will be seen

to move across the system boundary and to enter other systems. Examples of system

definition with respect to urban water and its system-environment are discussed in the

following section.

21

2.4.2 Perspectives on the urban water system

Because systems are dependent on observer definition, what infrastructure managers

perceive as the ‘urban water system’ will have profound planning, assessment, and

analysis implications. When managers’ and analysts’ conceptions are limited, the

options and alternatives available will also appear limited. For example, if water supply,

sewage and storm water infrastructures are viewed in isolation, then potentially

synergistic strategies that can have advantages across infrastructures, such as rain tanks

or local reuse of wastewaters may not be recognised. Similarly, if planners perceive the

boundary of the urban water supply system to be the property boundary, then demand

management programs will not be considered as an alternative to increasing bulk

supplies. Likewise whether or not recycling of nutrients back to agriculture is seen as a

required function of the urban water system will impact on decision-making about what

constitutes effective wastewater management.

Even when understood as a single entity, different definitions of urban water are

possible. Examples of varying understandings of the urban water system include: the

drinking water catchment, the dam, water treatment plant, the community, sewage

treatment plant and waterways (WQCRC, 2001); water supply, stormwater management

and wastewater infrastructures (Clarke et al. 1997; Pinkham 1999), an adaptive socio-

technical network (Guy, et al. 2001); all natural, modified or built water and

hydrological systems in an urban region (NZ PCE, 2000) or the technological

infrastructure, the organizational structures and the users of that infrastructure (Urban

Water, 2002).

With regard to assessment purposes, this thesis argues that a system such as urban water

is best understood in terms of a physical technical infrastructure and the operations of

that infrastructure including routine management practices. Higher-level organizational

structures (the institutional) are better considered outside the system, as these are the

elements that conduct strategic planning processes and are therefore engaged in

conducting assessments. Users of the infrastructure should also be considered as part of

the systems’ environment. This is because, as is argued below, in terms of

sustainability, urban water infrastructures are best understood as the system that

provides services to system-users (consumers).

22

In terms of sustainability, Schmidt-Bleek (1993), Von Weizsacker et al. (1997), Ayes

(1998) and others stress that production systems are best understood in terms of the

services they provide rather than the material commodities that are produced. With

infrastructures understood in these terms, it is asserted that much more resource

efficient and less polluting means of providing services then become apparent.

Likewise, in the context of sustainability, this thesis argues that our understanding of

utility infrastructure systems, such as urban water, ought to be in terms of the services

provided rather than the quantities of water supplied or treated.

In this thesis then ‘urban water’ is understood as being the provision of water services to

city or town or a predominantly residential part there-of. This includes water supply,

wastewater, and stormwater. Water supply services consist, at least, of potable water for

drinking and personal cleaning, as well as water for general cleaning, fire control, and

landscape irrigation. Wastewater services include sanitation, which is the effective

management of infectious materials, as well as more general removal of aqueous

wastes. Stormwater services entail the provision of adequate local drainage and the

avoidance of damaging flooding.

For Butler and Parkinson (1997) the sustainability of an urban water infrastructure

requires long-term operability and the ability to adapt to future demands. Citing

complex systems theory, Jeffrey et al. (1997) also perceive a sustainable urban water

system as one with both the potential and ability to adapt to changing conditions in its

environment. Urban water infrastructures that are designed and managed to be flexible

and adaptive to changes in either their system-environment or service requirements will

then be sustainable (Jeffrey et al. 1997).

Larsen and Gujer (1997) have a different view on the services that ought to be provided

by a sustainable urban water system. They define such a system in terms of the

provision of public health, personal hygiene, nutrient recycling services and ‘cultural’

services in the form of parks, fountains and ponds. Whether personal hygiene and

nutrient recycling to agriculture are treated as services provided by the urban water

system is a matter of (system) definition. If not deemed as ‘urban water services’ these

aspects can still be considered in planning or assessment as components of the urban

water system’s environment.

23

2.4.3 Perspectives on the system-environment of urban water

An urban water infrastructure, like any system, exists within a surrounding context of

other systems. When considering the sustainability of such an infrastructure the system-

environment must contain many more components (other systems) than it might

conventionally. The sustainability context of an urban water infrastructure also extends

beyond the local and regional level. In an example of the hierarchical nature of systems,

the sustainability of an urban water infrastructure can be conceived of as a sub-issue of

the sustainability of local community or catchment which is a sub-issue of the

sustainable development of a city, which in turn can be conceived of as sub-issues of

sustainable development of society in general (Grigg, 1999). To a significant degree,

perception of sustainable urban water will be shaped by the level or ‘sphere of

influence’ at which concern is focused.

Figure 2.3 shows the system-environment of urban water based on there being ‘spheres

of influence’ from the local to the global. In accord with the argument made in section

2.3 concerning the primacy of ecological limits, which was illustrated in figure 2.2, the

global ecological system is placed outside the social systems (which in turn contain the

anthropogenic and economic systems).

Sustainable

urban water

Figure 2.3 ‘Spheres of influence’ in the system-environment of urban water

Newman and Kenworthy (1999) contend that the local impacts of a given urban water

infrastructure, depicted in the inner circle of figure 2.3, will always appear the most

immediate and will normally be the attention of focus. Despite this, for sustainability,

24

they argue, it is the issues in the outer rings, which should be addressed first. Only when

the role of urban water infrastructures in sustainable cities and society are addressed can

optimisations be made in terms of impacts at the more local level. This thesis agrees for

the most part with Newman and Kenworthy’s contention, however, the potential for

local and regional issues to be critical is some instances must also be acknowledged.

The local level

The system-environment of urban water, at the local level, can be seen to include a local

community, incorporating the economic system, community health, institutional

structures and other infrastructure systems, and a local catchment covering landscape

and local ecosystems (see figure 2.4 below). Similarly, Grigg (1999) argues that urban

water infrastructures are linked inextricably with the built, social, and natural systems of

their surrounding urban area.

Catchment

Landscape Ecosystems

Community Institutional Other infrastructures

Economic Users/customers Public health Figure 2.4 The local system-environment of urban water

The sustainability of urban water can be understood in terms of the role of water

infrastructures in a sustainable community, or equally, their role in a sustainable urban

catchment. The relationships an urban water infrastructure has in its local system-

environment include: ecotoxic and eutrophic effects on aqueous ecosystems from

released pollutants, the financial costs to consumers, the mitigation of flood damage,

and the potential of waterborne infection in the community.

Systems, particularly social systems (the community) within the local system-

environment will influence how the urban water infrastructure functions are sustained.

For example, an urban water infrastructure requires the continued payment of bills,

adequate management and operation and the avoidance of excessive vandalism. In turn,

the maintenance of critical local systems functions such as public health and ecosystem

integrity will be dependent on the role of the local urban water infrastructure.

Urban water

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The regional or city level

Beyond the local, at city or regional level, the context of an urban water infrastructure

includes the water infrastructures’ impact on the structure and operation of the city and

its surrounding region. Key roles for an urban water infrastructure in a city include:

maintaining industrial capacities; providing equitable access to services; managing

material flows; controlling outbreaks of communicable disease; and avoiding major

disasters such as flooding and fires. In accord with the partition of issues at the local

level into interactions affecting catchment or community, at the city and global levels

concerns can be divided in terms of the biophysical and socio-economic aspects of

sustainability.

Newman and Kenworthy (1999) understand the biophysical sustainability of cities in

terms of an ‘extended metabolism model of human settlement’ which is analogous to

the metabolism of the human body. Using this metaphor, cities are perceived as a

system metabolising renewable and non-renewable resource inputs into useful products

and wastes. The useful products, together with other aspects of the city, produce a level

of liveability. Most products eventually end up as waste. In general, the greater the

resource inputs, the more waste. A sustainable city system is therefore one that can

significantly reduce the levels of resource inputs required, while maintaining or

enhancing liveability.

Considering the biophysical relationship between cities and regional areas, the type of

urban water infrastructure will have a significant impact. It will affect how much water

is appropriated by the city, whether pollutant effluents are released and whether

nutrients originating in agricultural soil are returned.

The spatial layout of cities will have a significant bearing on their levels of resource use

(Newman and Kenworthy 1999) and therefore their biophysical sustainability. In cities,

spatial interactions between urban water infrastructure and the natural landscape will

affect other urban infrastructures such as solid waste, transportation, energy distribution

and the location of buildings. One way of understanding the sustainability of urban

water is then in terms of the impact that infrastructure alternatives will have on urban

form and the layout of cities more generally (Mouritz 1996).

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Urban water infrastructures are critical systems within our cities from a socio-economic

perspective. The positive economic and social impacts that well functioning urban water

infrastructures have on cities are general accepted but largely ignored until failure

occurs (Harremoes, 1999). This includes the safeguarding of public health, the security

of property and permitting continued residential and industrial development.

Important aspects of the regional system-environment that will infl