Urban Water Sustainability

Constructing Infrastructure for Cities and Nature

Sarah Bell

• Publisher: Routledge
• Year: 2017
• eBook ISBN: 9781317398288
• Edition: 1
• Topic: Tecnología e ingeniería
• Subtopic: Planificación urbana y paisajismo

The provision of a safe and reliable water supply is a major challenge for the world's growing urban populations. This book investigates the implications of different developments in water technology and infrastructure for urban sustainability and the relationship between cities and nature.

The book begins by outlining five frameworks for analysing water technologies and systems - sustainable development, ecological modernisation, socio-technical systems, political ecology and radical ecology. It then analyses in detail what the sustainability implications are of different technical developments in water systems, specifically: demand management, sanitation, urban drainage, water reuse and desalination. The main purpose of the book is to draw out the social, political and ethical implications of technical changes that are occurring in urban water systems around the world, with positive and negative impacts on sustainability.

Distinguished from existing social science analysis due to its attention to the engineering details of the technology, this book will be of use to a wide audience, including students on water management courses, engineering students and researchers, urban geographers and planners interested in sustainability, infrastructure and critical ecology.

1 Introduction

Urban water sustainability

Water has always been an active constituent of cities. It is a basic requirement for human health and wellbeing, a source of risk through flooding and contamination, a remnant of natural hydrology and ecology in streams and wetlands, a transport route along rivers and canals, and an element of urban design in fountains, ponds and water features. Water infrastructure allows cities to function safely within upper and lower hydrological limits – providing a constant supply of water during dry seasons and droughts, and preventing flooding during high rainfall events. It allows urban citizens to go about their daily lives without being preoccupied with where their water is coming from or going to. Sustainable urban water systems aim to achieve this within environmental limits to water, energy and pollution, in ways that are affordable and equitable and contribute to ecological restoration.

Urban water sustainability aims to manage water in cities to provide for human health and wellbeing within hydrological and ecological limits. Urban water systems include drinking water supply, wastewater disposal, surface water drains and the rivers, streams, wetlands and aquifers of urban water catchments. Urban water sustainability is presented under different labels, for example, sustainable urban water management (SUWM), integrated urban water management (IUWM), and water sensitive cities. As a progressive movement, it anticipates positive change in cities. Sustainable urban water systems are commonly represented as future urban water systems, developed in response to resource constraints, growing populations and climate change.

The sustainability of urban water infrastructure must account for the relationship between the city and its hydrological catchments. Urban water use and pollution have impacts in catchments beyond the city limits. As infrastructures expand to meet growing demand, catchments for urban water supply and waste discharge do not necessarily conform to the geographical boundaries of river basins. Cities draw on regional water resources and some use water transferred over long distances. Urban wastewater and runoff pollutes rivers, estuaries and coastal environments. The energy used for pumping and treatment of water and wastewater also creates wider impacts and demands on the environment. How water is managed in cities affects health, wellbeing and the environment locally, regionally and globally.

Urban water crises?

Consistent with global environmental discourse, professional and academic movements in support of urban water sustainability are typically founded on the premise that current water systems are unsustainable. The case for the unsustainability of existing infrastructure is made in terms of limits to freshwater resources, environmental impacts of water abstraction and pollution, growing demand for water due to population growth, rising costs of infrastructure provision, replacement and expansion, vulnerability to droughts and floods, and climate change (Marlow et al., 2013; Mitchell, 2006; Niemczynowicz, 1999; Novotny et al., 2010). Sustainability is presented as the means to avoid crises of water shortages and floods in cities, and the related concept of resilience enables sustainable cities to respond more effectively to extreme events, such as drought and flood, which are more likely in an uncertain future (International Water Association, 2015).

Water scarcity provides some of the most alarming projections and warnings about climate change, population growth and development in popular and policy discourse. However, increasing water scarcity in most regions will be driven by increasing demand for water, rather than decreasing supply due to climate change, and the experience of insecure water supply for the world’s poorest people is most often the result of political and economic failure, rather than hydrological constraints (Arnell, 2004; Zeitoun et al., 2016).

Water is important for sustainable cities, but cities have a relatively small direct impact on the sustainability of global water resources. Globally, around 70% of water is used for agriculture, 10% for municipal supply and the rest for industry (Oki and Kanae, 2006; Shiklomanov, 2000). Global and regional forecasts of water scarcity mostly result from unsustainable abstraction for agriculture. Given that more than 50% of the global population live in cities, urban food consumption rather than urban water use is the most significant factor in achieving sustainable water resources management at the global scale (Allan, 2011).

Urban water sustainability is a global goal for development and environmental protection, but it is experienced in localised contexts under conditions of inherent uncertainty. Global and regional assessments of water resource availability can hide specific local conditions. Whilst municipal water supply may not constitute the largest proportion of global water resource use, an individual city can have significant impact on the hydrology of its local catchment (United Nations Human Settlements Programme, 2006). Local hydrology, ecology, urban form, governance, climate, economics, society and other factors shape the form of urban water infrastructure and responses to problems of water scarcity, pollution, flooding and access to water and sanitation services. Cities in the Global South may be focussing on provision of water and sanitation services to a rapidly growing population, while cities with established infrastructure focus on reducing demand and pollution, and restoring degraded freshwater ecosystems (Russo et al., 2014; UN-HABITAT, 2003; Wong and Brown, 2009).

It is common in urban water sustainability to speak of the need for a paradigm shift. Authors including Brown et al. (2009), Novotny et al. (2010) and Allan (2006, 2005) position an emerging paradigm of sustainability and integrated water management in the context of a longer history of water infrastructure. Brown et al. (2009) analyse the history of urban water management in Australian cities and identify six regimes, beginning with early European settlement and projecting into the future. The regimes are the water supply city; the sewered city; the drained city; the waterways city; the water cycle city; and the water sensitive city. Novotny et al. (2010) identify four historical paradigms from ancient times to the modern era: basic water supply; engineered water supply and runoff conveyance; fast conveyance with no treatment; and fast conveyance with end of pipe treatment. They make the case that a fifth emerging paradigm of sustainability will lead to the creation of water-centric ecocities. Tony Allan (2006, 2005) analyses the history of hydro-politics to identify five paradigms of water management – pre-modern; industrial modernity and the ‘hydraulic mission’ of large-scale infrastructure; environmental awareness; the economic value of water; and integrated water resources management (IWRM), which is still emergent. Allan’s analysis recognises paradigms as policy discourses, which may co-exist and contradict each other, in contrast to more linear, progressive notions of paradigms inevitably leading towards sustainability.

The global discourse of environmental crisis that underpins much of the justification for sustainable development and the need for new paradigms of urban water management sits somewhat uncomfortably with the experience of water infrastructure in most cities. Cities can have significant impacts on local water resources and ecosystems, but lack of access to water in cities is rarely the result of water scarcity. Inadequate water and sanitation is usually due to lack of infrastructure, not lack of water (Bakker, 2010; Cook and Bakker, 2012; Zeitoun et al., 2016). With notable exceptions in recent years, few cities in the world face absolute water scarcity sufficient to risk public health. Infrastructure management is typically a bigger factor in water shortages than lack of resources.

Providing water and sanitation to a growing population is undoubtedly challenging, and will impact local resources and ecosystems, but water resource constraints are not the only, or even the most important, factor driving the move towards more sustainable water systems. Beyond alarmist calls to avert catastrophic collapse, urban water sustainability provides an opportunity to reconsider how cities relate to water resources and the natural environment. Water systems reflect wider sustainability challenges of reducing consumption and pollution, improving equality of access and providing a safe environment in which people and nature can thrive.

Constructing infrastructure

Urban water infrastructures, whether sustainable or not, are human inventions. The particular form of an urban water system is an outcome of design and decision-making. Infrastructure is more than pipes, pumps and treatment works. Infrastructure systems cannot operate without ongoing administrative and institutional structures. They include systems of management, regulation, governance, finance and expertise. Water infrastructures do not exist in technical isolation, but are always deployed within political and social contexts, and are shaped by different knowledge and values. Just as the form of pipes and treatment vary in different cities around the world and at times in history, so the forms of governance and administration of infrastructure also change. Infrastructure is therefore constructed – physically and socially.

The form of water infrastructure shapes and responds to daily life in cities. Water infrastructure that was intended to improve public health has evolved to meet demand for water for automatic washing machines, dishwashers, showers, swimming pools, car washing, lush lawns and candlelit, scented bathtubs (Shove, 2004). The provision of constant water supply and wastewater disposal, as well as reliable drainage networks, have opened up new ways of living in cities. Infrastructure and society are constantly co-evolving in cities, with important implications for resource demands and ecological integrity.

In order to understand the role of technology and infrastructure in sustainable cities it is therefore important to be able to discern how their meanings are constructed within different cultural narratives and political discourses, as well as to understand their technical and physical performance. This is particularly important given the long-term nature of sustainability. Political and cultural discourse can change rapidly, while infrastructure may last for centuries and hydrological systems adapt and evolve over millennia. Understanding the relationship between technology and politics allows for longer-term strategies as well as short-term tactics in building cities that support good public health, and human and ecological flourishing.

How cities relate to nature is a political, ethical and technical choice. Infrastructures reflect shared values and priorities in achieving sustainable development. Is water a natural resource to be refined and distributed to meet endlessly expanding demand? Is it a scarce resource best allocated using the market? Is it a threat to human settlements and development, a risk to be managed? Is it a habitat shared by other species and the basis of healthy ecosystems? Is it the source of spiritual healing and reflection? Is it a human right, essential for good public health? How technologies are developed and deployed now and in the future depends upon the questions asked and the stories told about water in cities, as much as on the technical calculations and physical properties of science and engineering. Understanding and achieving urban water sustainability requires the capacity to discuss technologies, values and nature together.

Frameworks

Different infrastructure and technology choices have different costs and benefits to different people and the environment. Different theoretical and political frameworks understand those relationships in different ways. To make better decisions, design better infrastructure and create useful knowledge about urban water systems, it is helpful to be able to recognise these different positions and their implications. Theories about technology and society can provide structure to analyse different developments towards and away from sustainability in urban water systems.

Understanding how theory and politics frame debates and decisions about urban water sustainability highlights diversity and fragmentation within a relatively recently established field of research and practice. Identifying alternate framings of sustainability and technology may help to explain breakdowns in interdisciplinary and cross-sectoral research and practice. Disciplinary and sectoral silos have long been identified as obstacles to integrated approaches. This is commonly talked about as a language barrier, with each discipline having its own exclusive, specialist terminology. Jargon undoubtedly makes communication difficult, but interdisciplinary ventures still falter even when care is taken to speak in plain language. Professional and academic disciplines not only have their own languages; they also have their own frameworks – shared meanings and stories about how their knowledge contributes to improving the world. Misunderstanding and conflict can arise when frameworks are misaligned. Identifying the most common discursive and conceptual frameworks that underpin alternative narratives may help to explain, if not resolve, some of the challenges of interdisciplinary work in urban sustainability.

Urban water sustainability is simultaneously a unifying proposition for a progressive, positive future and a set of divergent strategies for social, political and technical transformation. As such, it reflects wider debates within environmental politics. Five distinct but overlapping frameworks can be identified in urban water sustainability – sustainable development, ecological modernisation, socio-technical systems, urban political ecology and radical ecology. Sustainable development is the familiar framing of the need to deliver the benefits of development to the global population within ecological and resource limits (WCED, 1987). Ecological modernisation promises that environmental problems can be solved by reforming the institutions of modern society, with a central role for technological innovation (Mol, 2000). Socio-technical systems emphasise the co-evolution of technology and society in identifying opportunities to transition towards more sustainable infrastructure (Geels, 2002; Vliet et al., 2005). Political ecology frames sustainability as a socio-environmental problem and highlights the connections between social inequality and ecological degradation (Swyngedouw et al., 2002). Radical ecology makes the case for fundamentally reconfiguring relationships between nature and society, emphasising the value of nature in its own right (Merchant, 1992). Frameworks can be used in three ways: as an analysis tool, to identify assumptions underlying various propositions for sustainability; as a normative standpoint, to define how sustainability should be achieved according to a particular set of values; and pragmatically, to align propositions for change within a dominant political and theoretical discourse.

Technologies

The role of technology and infrastructure in sustainability is contested. For some critics, modern technology is depicted as the source of pollution, as responsible for the exploitation of people and natural resources and for the destruction of ecosystems (Foreman and Haywood, 1993; Meadows et al., 1972). For technological optimists, environmental degradation and economic inequalities are side effects of incomplete modernisation, and technology is the means to improve resource efficiency and reduce pollution (Asafu-Adjaye et al., 2015). Most people recognise that technology is both a cause and a potential solution to environmental problems, and that it is necessary but not sufficient to achieve sustainability. There remains significant diversity in how the role of technology and infrastructure are understood in different sustainability frameworks. Characterising these different perspectives helps one to understand broader debates, policies and approaches to urban water sustainability.

The complexity of urban water sustainability may be revealed by analysing the main trends and technologies that have emerged in water infrastructure since the 1960s. This book addresses five technical trends and drivers in future urban water management – demand, sanitation, drainage, reuse and desalination. Focussing on these five specific categories of technology and water management grounds the analysis in a set of identifiable, tangible, material changes that are underway in cities around the world.

Classical approaches to urban infrastructure are founded on expanding provision to meet growing demand (Butler and Memon, 2005). Demand for water and sanitation services remains unmet in many cities in the Global South, w...

Table of contents

• Cover
• Title
• Copyright
• Contents
• List of figures
• List of tables
• List of boxes
• Preface
• Acknowledgements
• 1 Introduction
• 2 Water and sustainable cities
• 3 Constructing infrastructure
• 4 Framing cities and nature
• 5 Demand
• 6 Sanitation
• 7 Drainage
• 8 Reuse
• 9 Desalination
• 10 Conclusion
• Index