Steven Kenway

THE INS AND OUTS OF WATER USE – A REVIEW OF MULTI-REGION INPUT–OUTPUT ANALYSIS AND WATER FOOTPRINTS FOR REGIONAL SUSTAINABILITY ANALYSIS AND POLICY

This paper reviews current knowledge about water footprints (WFs) and the role of input–output techniques. We first provide an overview of the prevailing ‘bottom-up’, process-based methods and their strengths and limitations. This overview leads to discussion of the benefits of combining process-based water footprints with information from input–output techniques. The central theme and proposition is that environmental multi-region input–output analysis (E-MRIO) has a powerful capacity to establish the geography of embodied water, and to complement process-based approaches to WF by expanding their supply-chain coverage. Combining process and input–output information provides valuable information for a diverse set of water planning and water policy objectives. A comprehensive and systematic outline of potential policy applications of E-MRIO (and process analysis methods) is presented.

Urban Water Mass Balance Analysis

Planning for “water‐sensitive” cities has become a priority for sustainable urban development in Australia. There has been little quantification of the term, however. Furthermore, the water balance of most cities is not well known. Following prolonged drought, there has also been a growing need to make Australian cities more water self‐reliant: to source water from within. This article formalizes a systematic mass‐balance framework to quantify all anthropogenic and natural flows into and out of the urban environment. Quantitative performance indicators are derived, including (1) degree of system centralization; (2) overall balance; potential of (3) rainfall, (4) stormwater, and (5) wastewater to offset current demand; and (6) water cycle rate. Using the method, we evaluate Sydney, Melbourne, South East Queensland and Perth using reported and modeled data. The approach makes visible large flows of water that have previously been unaccounted and ignored. It also highlights significant intercity variation. In 2004–2005, the cities varied 54% to 100% in their supply centralization, 257% to 397% in the ratio of rainfall and water use, 47% to 104% in their potential stormwater recycling potential, and 26% to 86% in wastewater recycling potential. The approach provides a practical, water‐focused application of the urban metabolism framework. It demonstrates how the principles of mass balance can help foster robust water accounting, monitoring, and management. More important, it contributes to the design and quantitative assessment of water‐sensitive cities of the future.

New multi-regional input–output databases for Australia – enabling timely and flexible regional analysis

ABSTRACT Decision-making at regional scales requires timely information. Within four months of the release of official national statistics, we have produced a time-series (2008–2015) of balanced sub-national, multi-regional supply-and-use tables (MR-SUT), integrated with a set of socio-economic and environmental accounts. This was achieved using the Australian IELab, where data used in this study are available (https://ielab.info/resources/91). Four multi-regional, environmentally extended supply-use tables regionalised in different ways were produced to demonstrate the flexibility of tailoring input–output models to specific research or policy questions. Results for satellite coefficients are sensitive to the chosen regional grouping and method for regionalisation. We demonstrate the relevance of such purpose-built information to government and corporate decision-makers by analysing the indirect economic and employment consequences of a slowdown of the mining boom in Western Australia. The demonstrated innovations in flexibility and timeliness will help move past some of the limitations that have historically hindered the uptake and utility of applied input–output analysis.

Why do residential recycled water schemes fail? A comprehensive review of risk factors and impact on objectives.

In Australia, recycled water schemes have been implemented in residential developments to contribute to sustainable urban development, improve water supply security and reduce pollutant discharges to the environment. A proportion of these schemes, however, have been decommissioned well before the end of their design life which raises questions about the adequacy of the risk assessment and management practices adopted for recycled water schemes. Through a detailed literature review, an investigation of 21 residential recycled water schemes and in-depth interviews with nine scheme stakeholders, we identified 34 risk factors arising from six sources which have the potential to impact the long-term viability of residential recycled water schemes. Of the 34 risk factors identified, 17 were reported to have occurred during the development and implementation of the 21 schemes investigated. The overall risk rating of the 17 factors was qualitatively defined on the basis of the likelihood of occurrence and the impact of the risk factors on the scheme objectives. The outcomes of the assessment indicate that the critical risks to the long-term viability of residential recycled water schemes are 1. unanticipated operational costs, 2. legal and contractual arrangements, 3. regulatory requirements and approval process and 4. customer complaints and expectations not met. To date, public health risks associated with the provision of recycled water have been of primary concern, though the outcomes of this study indicate that the impact to public health has been low. Evidently there is a need for improved assessment and management practices which address the range of critical risk factors, in addition to the routine consideration of public health risks.

Quantifying and managing urban water-related energy use systemically: case study lessons from Australia

Abstract In this paper, three Australian case studies contribute to improved understanding of water-related energy quantification and management. A systems analysis of urban water in South East Queensland (Case Study 1) demonstrates the energy impact of water end use. In Melbourne (Case Study 2), water–energy interlinkages are explored within households. Finally, Case Study 3 in Sydney shows how abatement curves can help guide management action. Collectively, the case studies provide new information for least-cost solutions and simultaneous water and energy efficiency. The work highlights the need for frameworks to characterize and evaluate both the direct and indirect energy influences of urban water.

Expert opinion on risks to the long-term viability of residential recycled water schemes: an Australian study

The water sector needs to make efficient and prudent investment decisions by carefully considering the long-term viability of water infrastructure projects. To support the assessment and planning of residential recycled water schemes in Australia, we have sought to clarify scheme objectives and to further define the array of critical risks that can impact the long-term viability of schemes. Building on historical information, we conducted a national survey which elicited responses from 88 Australian expert practitioners, of which 64% have over 10 years of industry experience and 42% have experience with more than five residential recycled water schemes. On the basis of expert opinion, residential recycled water schemes are considered to be highly relevant for diversifying and improving water supply security, reducing wastewater effluent discharge and pollutant load to waterways and contributing to sustainable urban development. At present however, the inability to demonstrate an incontestable business case is posing a significant risk to the long-term viability of residential recycled water schemes. Political, regulatory, organisational and financial factors were also rated as critical risks, in addition to community risk perception and fall in demand. The survey results shed further light on the regulatory environment of residential recycled water schemes, with regulatory participants rating the level and impact of risk factors higher than other survey participants in most cases. The research outcomes provide a comprehensive understanding of the critical risks to the long-term viability of residential recycled water schemes, thereby enabling the specification of targeted risk management measures at the assessment and planning stage of a scheme.

How Does Energy Efficiency Affect Urban Water Systems

Urban water management influences significant energy use. In Australian cities, water management directly and indirectly uses 13 % of Australia’s electricity and 18 % of its natural gas. Collectively, it accounted for 8 % of the country’s primary energy use in 2007, approximately five times the direct energy use of the agricultural sector, excluding transport. Water-related energy consumption in cities includes energy used in the provision, consumption, and disposal of water. About 10 % is direct energy use by utilities. The majority of the figure relates to water used in homes, business, and government. There is scope for urban water management to reduce water-related energy use, particularly if strategies actively target the large amount of energy associated with water use.

Management of the urban energy-water nexus

The influence of urban water management on energy use is substantial. Approximately 8 per cent of Australias 2009 greenhouse gas emissions (24 t CO2-e/person) are influenced by water policy in cities. Much of the influence is associated with the use of water, in homes and industry. This is, consequently, ‘hidden’ from the much smaller (although still large) energy balances assessed and managed by water utilities. Understanding and managing this wider pool of energy is vital in order to avoid perverse impacts such as increasing greenhouse gas (GHG) emissions during water conservation efforts. The energy consumption of urban water in Australia is anticipated to grow 200 to 250 per cent by 2030, from 2007 levels, largely as a result of ‘climate resilient’ desalination and water reuse systems. This chapter argues that co-ordinated management of water and energy in cities is both a need and an opportunity to find efficient and low-cost solutions to water shortages and emissions targets. Such solutions will require integrated water and energy research, planning, funding, regulation, standards, data, targets and reporting. Collaboration across the industry sectors and government will be necessary to generate knowledge and policy in major gaps, including (a) quantification of links between water and energy in the industrial and commercial sectors, (b) understanding of the strong economic, social and institutional factors of relevance and (c) generate real understanding of the variability in the systems as opposed to the current over-reliance on ‘averages’. The significance of water-related energy in cities The energy associated with urban water provision in Australia in 2006-07 accounted for 13 per cent of national electricity use, plus 18 per cent of natural gas consumption. It totalled some 6,800 gigawatt-hours of primary energy use per 1 million people (Table 9.1; Kenway et al. 2011a), representing 9 per cent of Australian primary energy use.