Urban water security: water supply and demand management strategies in the face of climate change

ABSTRACT

Understanding the knowledge of climate-change impacts on water-resources is a priority. This article goes a step further with the main objective of this study to explore water-practitioners’ viewpoints regarding the water supply-side and water demand-side management measures in coping with future climatic impacts to achieve urban water security. Interviews were conducted with water-professionals from regional urban water authorities of Queensland, Australia. From a water-practitioner’s viewpoint, surface water is perceived to remain a high-priority water resource for the region, although climate-change is projected to make this resource more vulnerable in the area. Climate-change risks have rarely been considered as a selection-criterion when long-term water solutions were investigated by water-practitioners. Although non-pricing water demand management policies were used to reduce water demand in the region, pricing-based water demand management tools are perceived by the water-professionals to be the most effective at reducing water demand in the study area, if implemented.

KEYWORDS:

• Urban water
• Water security
• Water supply
• Water demand management
• Climate change

1. Introduction

Water plays a vital role in a sustainable economic development and the survival of human society. (Zucchinelli et al. 2021; Yao et al. 2020) Global water demand increased significantly, by nearly eightfold, between 1900 and 2010. This was due to a rapid growth in urban areas, irrigation and industrial development throughout the world (Ma et al. 2020). Global water demand is projected to increase by more than 50% by 2025 (Alshehri et al. 2021) and more than 65% of the global population is expected to face some form of water scarcity in the near future (Tajeri Moghadam et al. 2020). Decrease in water availability (Wang et al. 2014; Zucchinelli et al. 2021), increase in water demand (Caiado 2010; X-J et al. 2013), and deterioration of water quality (Zucchinelli et al. 2021) are likely future scenarios in many parts of the world. Water demand is likely to grow around urban centres of the world with increasing urbanisation. (Nazemi and Madani 2018; Shahangian Tabesh, Yazdanpanah, and Yazdanpanah 2021b) With growing water demand and increasing population around urban centres, there will be a need to find new water sources to maintain urban water security (UWS). (Allan, Kenway, and Head 2018; Daloglu et al. 2022; Shahangian Tabesh, Yazdanpanah, and Yazdanpanah 2021b). However, climate change and its associated hydrological impacts are likely to add significant water supply-side uncertainties to new and existing sources (Rasoulkhani et al. 2018; Pakmehr, Yazdanpanah, and Baradaran 2020, 2021), thus demanding an appropriate response to combat climate-induced impacts on UWS. (Biswas, Sharma, and Gyasi-Agyei 2022b) Whilst there is literature on the different potential climate change adaptation policy options for urban water authorities, these are predominantly done in fragments and the potential routes to adaptation have not been investigated well. (Biswas, Sharma, and Gyasi-Agyei 2022a) There is limited research on how climate change adaptation practices have successfully been strategised, developed and implemented in the urban water sector. Furlong, Gan, and De Silva (2016) studied urban water management in the face of climate change and climatic variations in Melbourne, Australia. They identified inconsistent approaches as policymakers were found to work on a reactive basis rather than taking proactive actions on many occasions. Van de Meene, Brown, and Farrelly (2011) concluded that slower implementation of sustainable water management is mainly caused by water policymakers or governing bodies, indicating a lack of common understanding on the urgency of preparing for long-term water security challenges.

UWS can be defined as managing and planning water supply and water demand for an urban area for current and future generations within reasonable costs and risks (Jensen, Wu, and Jensen 2018). Both water supply and water demand management (WDM) play a critical role in achieving a water organisation’s goals to manage and plan for UWS. Although focusing on water supply-side management is the opposite of water demand-side management for achieving UWS, the target of modern integrated urban water management (IUWM) is to explore both water supply and demand-side strategies to achieve and maintain long term UWS. Water supply measures include exploring different types of water resources including surface water, groundwater, stormwater harvesting, seawater, recycled water, and other water reuse schemes. Among these, freshwater resources are highly sensitive to climate change and climatic variations (Aliabadi, Gholamrezai, and Ataei 2020; Greve et al. 2018; Pakmehr, Yazdanpanah, and Baradaran 2021) as global warming is projected to cause changes to the amount of precipitation and its spatial distribution (Tariku and Gan 2018; X-J et al. 2013). Alternatively, other water resources including seawater and recycled water are comparatively less sensitive to climatic parameters. (Moshtagh and Mohsenpour 2019) WDM tools are comprised of different policies and techniques to reduce water demand. They include both water pricing-based policies and non-price-based WDM tools such as raising public awareness, smart water metering and technological advances to reduce water leakage. (Shahangian et al., 2021a; 2021b; Stavenhagen, Buurman, and Tortajada 2018)

Urban water authorities and water professionalsplay a critical role as their perceptions, priorities and viewpoints play a significant role in addressing climate-induced impacts on UWS. However, research on the impacts of climate change on water resources and adapting to this change is primarily done by the academic world. The perceptions and priorities of real-life water professionals are not yet clearly understood (Hurlimann et al. 2018; Laursen et al. 2018; Wijaya et al., 2020). In many cases, the decision makers are found to avoid research findings until a crisis point is hit. The lack of confidence on the applicability of research findings in real-world scenarios is also evident (Millington and Scheba 2021; Stauffer 2016; Linnenluecke, Griffiths, and Mumby 2015). The main objective of conducting this research is to explore water practitioners’ viewpoints regarding water supply-side and demand-side management measures in coping with future climatic impacts to achieve UWS.

The study consists of two parts. Firstly, a literature review was conducted on various components and subcomponents of climate change adaptation practices in the urban water sector and the different water resource and water demand-side measures used to achieve long-term UWS. Secondly, water professionals from regional urban water authorities of Queensland were interviewed to examine the priorities and perceptions of the practitioners on the effectiveness of the different long-term water supply security measures in a regional urban water context.Using the experts’ views, the focus of this study is to determine the effectiveness of water supply-side and demand-side measures in achieving long-term water security.

2. Study context

As part of this research, the regional urban water authorities in the northern tropical region of Queensland, Australia, were selected as case-study areas. Tropical Queensland extends from Far North Queensland in the north, the Mackay region in the south and west to Gulf Country. This region includes most parts of north Queensland and some areas of central Queensland. Due to climate change, this area is expected to experience high rainfall variability, an increase in temperature, more frequent hot days, an increase in evaporation and extreme opposing climatic conditions such as more frequent cyclones and drought events (CSIRO and Bureau of Meteorology BOM 2015; Queensland Government QG 2022; DEHP Department of Environment and Heritage Protection, State of Queensland 2017). Precipitation in the study region is predicted to change drastically between −30% and 20% by 2070 based on a high greenhouse gas emission scenario model (CSIRO and Bureau of Meteorology BOM 2015; Queensland Government QG 2022). In the case of a low greenhouse gas emission scenario, the projected rainfall variation is between −20% and+10% by 2070 (CSIRO and Bureau of Meteorology BOM 2015; Queensland Government QG 2022). Around a 1°C increase in temperature has been observed in the region in the last 100 years (DEHP Department of Environment and Heritage Protection, State of Queensland 2017) and is likely to increase further in the coming years (Queensland Government QG 2022). The study area is in a complex climate zone with the northern part classified as a wet tropic, whereas the southern part is classified as a dry tropic.

The area has three major regional urban centres, Cairns, Mackay, and Townsville (Figure 1), which are primarily dependent on local surface water resources for urban water supply. There are small pockets of population centres scattered throughout the region, but many of these areas are undeveloped and have a low population density, which is typical of remote regional Australia.

Figure 1. The location of regional cities (Cairns/Townsville/Mackay) in the study area.

There are approximately 650,000 people living in the tropical region of Queensland. Over 90% of which live in Townsville, Cairns and Mackay. (Australian Bureau of Statistics ABS 2016) Two rainfall dependent surface water dams, namely Ross River dam and Paluma dam, supply potable water to the urban community in Townsville. (Townsville City Council. TCC 2022c) The city experienced a major drought and subsequent water crisis in 2014–2018 (TWST, 2018) followed by a devastating flood event in 2019 (TCC, 2022a). The city of Cairns is in the northern wet tropic region, it depends on two major surface water resources, Copperland Falls Dam and Behana Creek. (Cairns Regional Council CRC 2022) Mackay depends on the Pioneer River water supply scheme and the Teembura Dam for its water supply needs. (Mackay Regional Council MRC 2022a) The city of Townsville achieved a substantial decrease (22%) in per capita residential water demand in the last decade, whereas both Mackay and Cairns achieved an 18% decrease in residential water demand in the last 10 years. (Townsville City Council. TCC 2022c; Mackay Regional Council MRC 2016, 2022a; Cairns Regional Council CRC 2022)

The urban water authorities are local city councils and regional government authorities. The Queensland state government agencies play a supportive role by providing coastal management documents and State Planning Policies (SPP) that outline the different guidelines for climate change adaptation to be implemented by the local regional urban water authorities. The Queensland Planning Act 2016 plays a major role in influencing local authorities in their climate change adaptation practices (QG, 2020). There are a few bulk-water authorities managed by state government agencies of Queensland that work in collaboration with the local urban water distribution authorities to manage and plan for water resources. The federal government is responsible for assets and/or areas of national significance but has a minimal role in local urban water management. Development and implementation of sustainable urban water in the face of climate change and climatic variations is primarily the responsibility of local government organisations in the study region.

Although integrated urban water, that includes exploring both water supply and water demand, is gaining importance in Australia’s urban water sector (Furlong, Gan, and De Silva 2016), there is limited research done that targets water supply and demand management practices of the regional urban water authorities in the Queensland tropics. However, it needs to be noted that there are a few reports/papers on water supply and demand management targeting large metropolitan cities of Australia. (Furlong, Gan, and De Silva 2016; Horne 2018; Wills et al., 2013; Willis et al. 2011) The importance of major WDM intervention drives such as water restrictions, public education and awareness, and rebate for water-efficient devices are acknowledged in these research papers. Additionally, reports have also been developed by the local, state and commonwealth governments of Australia giving high-level guidance and policy tools for water supply and demand planning. (Furlong, Gan, and De Silva 2016; Queensland Water Commission 2010).

3. Research methodology

The overall methodology of this research consists of two parts. (Figure 2) First, a literature review was conducted to find out the different elements of sustainable urban water management that adapt to the impacts of climate change, water supply-side and demand-side management strategies and how they are implemented in different parts of the world to achieve long-term water supply security. Then, a qualitative interview study of regional urban water professionals in the tropical region of Queensland was conducted to understand their perceptions on the implementation of a successful climate change adaptation practice in the urban water sector. This interview process was also to study their viewpoints and opinions on the different water supply-side and demand-side measures that have the potential to achieve long-term UWS.

Figure 2. Overall research methodology.

3.1 Literature review

A wide range of previously published literature was reviewed using keywords such as ‘water security’, ‘water supply’, ‘water demand’, ‘water authority’, ‘urban water’, ‘climate change’, ‘adaptation’, ‘resilience’ and ‘vulnerability’. Research papers were searched (Boolean search) from major research databases (SCOPUS, Web of Science, PROQUEST) covering the period from 1980 to 2022. Conference papers, and research reports (i.e. grey literature), were avoided unless these were perceived to be from prestigious sources, particularly practitioners’ reports, the primary focus largely being on peer-reviewed journal articles. Book chapters were not used in this study.

The literature review process including the selection of research papers using inclusion/exclusion criteria for article selection. The number of articles studied at different steps of the literature review is shown in Figure 2. Ninety-eight research papers were studied thoroughly as part of this study. As shown in Figure 3, more than 90% of the selected studies were conducted in the last 10 years, with majority being published in the last 5 years.

Figure 3. Research studies analysed as part of the literature review.

3.2 Interview study

3.2.1 Interview participants

In the case study area, there are 17 notable local authorities. Among these, the three major councils; Townsville City Council, Cairns Regional Council, and Mackay Regional Council supply water to more than 90% of the urban population in the region (ABS, 2016). Therefore, the interview participants were primarily identified from these three regional councils. The organisational structures of the local urban water authorities were at first analysed to identify potential candidates for the interview study. A project information file and a separate interview consent condition document were prepared for the potential interview participants. Appropriate human research ethics approval was obtained from the relevant Human Research Ethics Committee as approved by the NHMRC (National Health and Medical Research Council), Australia. The interview participants were informed about the project and research targets before the interview sessions to help them understand their suitability for the project. This helped the researchers to target the right candidates for the interview study.

Among the 20 water professionals who intended to participate in the interviews, five were water experts, six were planning engineers, four were sustainability experts and the remaining five were planning officers. The interviewees are coded/categorised into different sub-categories based on their employment departments and expertise (APPENDIX A). Opinions of different interview participants are defined in the paper (who said what) using these sub-categories and coding. It also needs to be noted that due to the confidentiality clause in the human ethics approval, the names of the participants and their employers’ names are not mentioned in this paper.

3.2.2 Interview data collection and analysis

In this research, both structured and semi-structured interview questions were used. In the structured interview, pre-defined questions with a set of response categories were used to get a consistent response from the respondents. (Miles and Hubernian, 1994) In the case of semi-structured interviews, a range of ‘how’ and ‘why’ type questions were asked to better understand the judgements and perspectives of the interviewees and analyse the reasons behind their opinions. (Daymon and Holloway, 2010) It is challenging to mention all the interview questions asked during the interviews as in many cases, questions were raised based on the response provided by the participants to get an in-depth understanding. An indicative list of interview questions relevant to this research study is outlined in APPENDIX B . It needs to be noted that this list is not exhaustive.

Using the structured interview method, the interviewees were asked to add priority/importance scores on different water supply-side and demand-side measures identified in the literature. Then, semi-structured verbal interview discussions were held to better understand the reasons behind the perceptions of the local urban water professionals. Starting from initial five interviewees, the number was increased by five at a time until 20. After 10 interviewees, data saturation was observed, and a consistent response pattern was noted. No notable changes in the response pattern were observed even after 15 interviews. Hence, 20 interviewees were considered adequate to understand the overall perceptions of the local urban water professionals in the region. All the interview discussions were audio recorded, the relevant information data were transcribed, thematic analysis was done and finally, a pattern matching and grounded theory (Yin 2009) were used as a data analysis method to understand the perceptions of the participants and the reasons behind them. The interview data were completely de­identified after the completion of data processing. The adopted data analysis method (pattern matching and grounded theory) allowed the researchers to understand the similarities and differences in perceptions among the interview participants and their individual reasons. The method helped the researchers to identify and analyse patterns, classes and sequences grounded in the interview data collected. It also helped in identifying and analysing different gaps and variances in response patterns applicable in the study region.

4. Results and analysis

In section 4.1 and 4.2, the results from the literature review are summarized and the interrelationships among different relevant parameters are established. The perceptions and priorities of the interview participants are presented and analyzed in section 4.3.

4.1 Climate change adaptation elements required to achieve a sustainable urban water management

Sustainable urban water management includes a wide range of critical elements of water supply including availability of water resources, WDM, water quality, climatic factors, stakeholder participation, economic resiliency and sustainability. (Biswas, Sharma, and Gyasi-Agyei 2022a; 2022b; Furlong, Gan, and De Silva 2016; Tortajada 2006) Table 1 summarises the different elements of climate change adaptation practice and work priorities in the urban water sector for a typical water organisation.

Table 1. Climate change adaptation elements.

Adaptation segments	Element	References
Climate change parameters – impact assessment	Sea level rise	Reager et al., 2016; Vu et al., 2018
	Rainfall variation	Haque et al., 2016; Tariku and Gan (2018); Engle (2012)
	Extreme climatic events	Haque, Rahman, and Samali (2016); Bates, Kundzewicz, and Wu (2008).
	Increase in dryness and evaporation	Helfer, Lemckert, and Zhang (2012); Tanzeeba and Gan (2012)
	Temperature variation	Helfer, Lemckert, and Zhang (2012); Tariku and Gan (2018); Bates, Kundzewicz, and Wu (2008)
Climate change risk perception and adaptation priorities for water authorities	The balance between water supply and demand	Benson and Lorenzoni (2017); Horne (2018)
	Uncertainty in the development and planning of water infrastructures	Azhoni, Jude, and Holman (2018); Brown et al. (2020); Young and Essex (2020)
	Economic resiliency	Biesbroek et al. (2013); Engle (2012); Maaike et al. (2020); Madsen et al. (2018).
	Legal liability and policy implementation	Azhoni, Jude, and Holman (2018); Baker et al. (2012)
	Stakeholder response and well being	Esteve, Varela-Ortega, and Downing (2018); Young and Essex (2020)
	Emergency risk (water crisis/scarcity) perceptions and priorities	Engle (2012); Horne (2018)
Available resource	Appropriate resource (funding and technical)	Simonet and Leseur (2019); Young and Essex (2020),
	External support (technical/economic support from external organisations)	Mcclure and Baker (2018); Measham et al. (2011)
	Stakeholder support	Baggett, Jeffrey, and Jefferson (2006); Esteve, Varela-Ortega, and Downing (2018); Young and Essex (2020)
	Policy tools and legislation	Azhoni, Jude, and Holman (2018); Biesbroek et al. (2013)
Urban water authorities – actions adapting to climate change	Assessment of the climate change impacts on water	Engle (2012); Biesbroek et al. (2013)
	Financial assessment including cost-benefit assessment for water augmentation and demand management	Maaike et al. (2020); Miller and Belton (2014); Eisenack et al. (2014)
	Stakeholder response and engagement for acceptable water supply security	Baggett, Jeffrey, and Jefferson (2006); Esteve, Varela-Ortega, and Downing (2018).
	Emergency action plan and implementation during water scarcity	Engle (2012); Horne (2018)
	Policy development and implementation	Haasnoot et al. (2013); Maaike et al. (2020); Simonet and Leseur (2019); Young and Essex (2020)
	Define, measure and track climate change adaptation actions (water augmentation/water demand parameters)	Haasnoot et al. (2013); Young and Essex (2020)

As evident from the literature review (Table 1), a climate change adaptation policy should have four major sections: impact assessment, risk perceptions and adaptation work priorities, existing policies and resources including availability of external support and, finally, a holistic implementation plan. A flow chart has been established taking various interrelated elements of climate change adaptation practice as identified in Table 1. (Figure 4)

Figure 4. Interrelationships among climate change adaptation elements in urban water sector.

Some of the key challenges for urban water organisations during the identification and implementation of adaptation priorities are uncertainty in the development and planning of water infrastructure, emergency response, appropriate resource allocation, and restoration and maintenance of the water infrastructure after severe climatic events. In addition, available internal and external support, including financials technical, community acceptance, and consensus with stakeholders to deal with climate change and climatic variations, need to be investigated and prioritised to achieve long-term water supply security.

4.2 Water demand and water supply management policies for the adaptation to the impacts of climate change

Urban WDM includes different policies to reduce water consumption in the short-term and long-term, including raising public awareness through education campaigns, water restrictions, smart technologies, water leakage management, water pricing strategies and other relevant water conservation measures. (Shahangian Tabesh et al. 2022; Stavenhagen, Buurman, and Tortajada 2018; Tortajada et al. 2019) Table 2 outlines different types of WDM strategies and their potential impacts on water consumption as identified from the literature review.

Table 2. Water demand management strategies to achieve long-term UWS.

Water demand management - key elements	Description	Impact on water consumption
Pricing-based WDM	Water demand management – pricing strategies: - Changes in water pricing - Changes in water billing structure and frequency	Low-moderate impact (Lu, Deller, and Hviid 2019; Tortajada et al. 2019; Inman and Jeffrey (2006); Stavenhagen, Buurman, and Tortajada (2018)High impact (Mansur and Olmstead 2012; March and Saurí 2010)
Non-pricing WDM	Smart technologies, water leakage management, policy development etc. Raising public awareness and education campaign	Low - moderate impact (Inman and Jeffrey 2006) High impact (Rajala and Katko 2004; Stavenhagen, Buurman, and Tortajada 2018) Low-moderate impact (Stavenhagen, Buurman, and Tortajada 2018) High impact (Tortajada et al. (2019)
Emergency WDM	Emergency WDM plan includes water restriction and emergency contingency planning. Emergency contingency plan may include any possible combinations of pricing and non-pricing WDM policies.	High impact during emergency/drought (Drysdale and Hendricks 2018; Engle 2012; Horne 2018); Voluntary water restriction not very effective (Horne 2018; Kenney et al. 2008)

In general, WDM policies are divided into pricing and non-pricing policies (Ramsey Berglund and Goyal 2017). These are further split into three major categories being economic, technological and behavioral (Lee, Tansel, and Lee 2013; Shahangian Tabesh et al. 2022). In this paper, the WDM policies are divided into three sub-categories namely pricing based WDM, non-pricing WDM, and emergency WDM. Additionally, non-pricing WDMs are subdivided into two sub-categories being a) raising public awareness and education campaigns, b) any other remaining non-pricing WDM policies/tools. As evident from the literature review (Table 2), although all the identified WDM tools are effective to reduce water consumption, the relative impacts of these tools are found to vary from one study to another.

Climate change is projected to cause depletion of surface water sources (Wang et al. 2014; Zucchinelli et al. 2021), variation in rainfall events (Haque, Rahman, and Samali 2016; Tariku and Gan 2018), saltwater intrusion into groundwater (Vu, Yamada, and Ishidaira 2018), and sea level rise (Reager et al. 2016) in different regions. However, considering the uncertain and variable nature of climate science, the extent of climate change impacts cannot firmly be estimated. Table 3 summarises the key findings on the available water resource options and policies suitable to be explored for the adaptation to the impacts of climate change.

Table 3. Water resource options to be explored to achieve long-term UWS.

Water supply options	Water resource infrastructure elements	Limitations and challenges
Freshwater resource	Surface water	Highly sensitive to the impacts of climate change and climatic variations. (Ahamad et al. 2013; Wang et al. 2014; Zucchinelli et al. 2021) Climate induced changes in aquifer levels and saltwater intrusion into groundwater are identified as critical challenges for groundwater resources. (Vu, Yamada, and Ishidaira 2018) Success of stormwater harvesting is highly dependent on the rainfall amount, rainfall pattern and spatial distribution of rainfall (Aliabadi, Gholamrezai, and Ataei 2020)
	Groundwater
	Stormwater harvesting
Alternative water resource	Seawater (desalination plant)	Alternative water resources are comparatively more costly then using traditional freshwater resources. (Lefebvre 2018; Moshtagh and Mohsenpour 2019; Smith et al. 2018) Climate change and climatic variations will have comparatively less impacts on the alternative water resource options identified. (Lefebvre 2018; Moshtagh and Mohsenpour 2019) Significant cost is involved to develop and operate desalination plants. (Baggett, Jeffrey, and Jefferson 2006; Hanak and Lund 2012; Sowers, Vengosh, and Weinthal 2011)
	Recycled water and other water reuse scheme

Depletion of available water supply sources prompts water utilities to devise and develop policies aimed at achieving sustainable water management by keeping in mind the long-term water demands and climatic uncertainties. Freshwater sources such as surface water, ground water, and stormwater harvesting are sensitive to climate change. Although technological advances can allow water authorities to optimally maintain and manage these water supply sources, they will remain vulnerable due to their dependency on local climatic conditions and parameters. Several urban water authorities have identified desalination plants as alternative water sources for emergency water shortage scenarios. (Hanak and Lund 2012; Sowers, Vengosh, and Weinthal 2011) Although desalination plants are a promising option for urban water supply, the significant cost to develop and operate a plant and the environmental impacts cannot be ignored. In addition to cost prohibition, it may not be a feasible option for urban centers that are too far from the coast. Water-reuse is gaining importance in recent times, but further technological advances are required for this to have a significant impact on the urban water sector (Smith et al. 2018).

In summary, once climate change impacts on urban water resources are perceived, the next step for an urban water authority is to investigate climate change risk and adaptation work segments and priorities to achieve long-term water supply security. The various interrelated areas of climate change and adaptation practices in the urban water sector as identified from this research (section 4.1 & section 4.2) are summarized in the flow chart below (Figure 5).

Figure 5. Adaptations to climate change to achieve long-term UWS.

Strategies can be developed for large-scale infrastructure projects such as new water supply sources, dams, and treatment plants, thus helping communities to cope with future drought events. Among the water resource augmentations, urban water authorities can explore freshwater resources versus alternative water resources for the short-term and long-term. At the same time, plans could be devised and implemented for different proactive action plans such as WDM (e.g. pricing vs non-pricing) and community participations and engagement.

4.3 Perceptions and priorities of urban water professionals: Implementation of climate change adaptation practice and the various elements of UWS

The purpose of the interview study was to understand the perceptions of local urban water practitioners about the implementation status of climate change adaptation practice and the various elements of UWS. To the authors’ best knowledge and as also outlined by the interviewees, there are no comprehensive guidelines and/or implementation plans in place for climate change adaptation in the tropical urban region of Queensland. Implementation of climate change adaptation works is done in fragments in the region and are not clearly defined or documented. Some of the notable comments received from the interview participants were:

“we have a lot of documents on coastal hazard and flooding … . not necessarily related to climate change … .don’t think councils have any good policy on climate change adaptation … ” … (SE1)

“I would say no … . no implementation framework that informs climate change adaptation works … the roles and responsibilities … there is no good strategy or plan … ”(WE2)

“ … there are some policies … but how to implement the policy is changing continuously … . there is no consistency … . there is guideline but it is hard to implement … . lack of justification or background information … ”(PO1)

“Some guidelines in planning schemes have climate change as an element … . there is costal hazard overlay that considers coastal hazards as part of climate change … some guidelines are there that tells how climate change can be considered in flooding assessments … .but … .no we don’t have any good implementation framework … I don’t think the council has any concrete position on what that is … what we need to do and how we need to do … ”(PE2)

According to the interviewees, the implementation of climate change adaptation primarily targets adaptation to coastal hazards including coastal erosion, sea level rise, storm surge and cyclones. There are high-level climate change policy documents, local government development manuals and city planning guidelines that do recognise climate change as an important element (Cairns Regional Council CRC 2022; Townsville City Council. TCC 2022a; Mackay Regional Council MRC 2022b), but it appears that climate change is not incorporated well into their implementation framework. The current practice is perceived to have loopholes including a lack of mandatory rules and requirements, thus allowing a wide range of leniency during infrastructure augmentation and the development approval process.

Relating to water supply-side and demand-side measures, the participants were asked what options the local urban water authorities should explore more and implement when it comes to climate change adaptation in order to achieve long-term UWS. Although it was suggested that both water supply-side and demand-side measures should be considered holistically, water demand-side measures were perceived to be more important and reliable than the water supply-side measures. Some of the notable comments received during the interview study were:

“Water demand is more important than anything else … .demand reduction in one side and water source optimisation on the other side is important … ”(WE2)

“ … . I think water demand management will play more and more … . important role as climate change is going to affect water resource … .if we reduce our consumption it will not only help in economic savings … .but also in long-term water supply security … ”(PE6)

“We need to educate our community … .I think water demand should be given more importance than water supply source … . if we can manage it well … that’s fantastic … ”(PO5)

“water demand drives water supply source options we need … . we need to consider both … .water supply and water demand … ”(PO4)

Increase in water demand due to climate change is not considered a critical element by the local water scholars, although there are few research works done on this topic (Caiado 2010; X-J et al. 2013; Zubaidi et al. 2020). Interview participants from the case study region were asked to score the importance of pricing vs non-pricing WDM policy options in the face of long-term water supply security challenges including climate change impacts and climatic variations. The results are discussed in detail by Biswas, 2023a , 2023b and Biswas et al., 2022a.The key findings are summarized in Figure 6.

Figure 6. The importance of pricing vs non-pricing WDM policies to achieve long-term water supply security in the face of climate change by the interviewees.

Among the WDM policy options, non-pricing WDM policy tools, such as raising public awareness and education campaigning, leakage management, and water saving technologies (including smart water metering), are being implemented in the region (Cairns Regional Council CRC 2022; Mackay Regional Council MRC 2016; Townsville City Council TCC 2021). Pricing-based WDM is perceived to be the most effective way to reduce water demand, if implemented. Among the other WDM policies, raising public awareness and education campaigning received a very good score. From the expert’s viewpoints, raising public awareness and education campaigning is perceived to be critically important to making any policy successful when it comes to WDM irrespective of whether it is a pricing based WDM policy or a non-pricing WDM policy. Additionally, well-documented water restriction policies exist in local water organisations, and these have been implemented in some parts of the region in the past.

In the case of water resources, the interview participants were initially asked to score the importance of different water supply source options, that adapt to the impacts of climate change in the study region, to achieve long-term water supply security (Figure 7). The scoring was followed by verbal discussions.

Figure 7. The importance of different water supply source options for long-term urban water supply security that adapts to the impacts of climate change in the Queensland tropics as indicated by the interviewees.

Some of the important comments received during the interview study were:

“two options I will pick as part of water source in the face of climate change … . One is desalination plant … using sea water … second one is recycled water … these are the options … in case of ground water and river water we depend on rainfall … but it will still be important here … ”(WE1)

“ it is a difficult topic … .integrated water supply strategy is important … we are having an extensive investigation on all the water supply resource options … . Our surface water resource … dam … . Will always remain important … . efficiency in management and operation can be considered … . Integrated water supply approach is critical … . surface water is more cost effective than any other approach … ”(SE3)

“I think definitely … we need more water dams and surface water provisions … . Rainfall will always remain critically important … . desalination is a great idea … . But it is going to create other problems … recycled water is also a good option … it is all going to help … ”(PO5)

“ … most impacts of climate change will be on water resources … . securing water may not be an issue … surface water resource is there … it is probably the cost we are mostly worried about … ”(PE2)

“ … groundwater depleting, desalination not an option for inland council … .water reuse is the option … .it is something needs to be investigated … ”(SE1)

“. desalination is really costly … we need to find something that is economical … we will need to find more surface water option as it is cheap … . preserve the availability of surface water … . the option can also be … . Recycled water”(PO1)

Surface water resources received a ‘high priority’ score. Saltwater intrusion into groundwater is not considered a major concern in the region despite the backdrop of the recognition of seawater level rise as an important element in the relevant coastal adaptation policies in Queensland (CoastAdapt 2021), and the several studies currently being conducted on this subject (Lal and Datta 2021). Desalination plants received the lowest priority score among all the water resource options due to cost constraints. Water reuse is considered a valuable option and is already acting as an alternative water supply source in the region for non-potable water demand for some local parks and golf courses. This has been implemented in all the major urban centers, and a varying level of success has been achieved in this arena.

5. Discussions

Appropriate consideration of climate change risks is essential for a sustainable water supply to customers within affordable price limits. There is no defined guideline for this as different regions face different water security challenges, and the relevant policies in the urban water sector for one region may not be suitable for another. Successful, sustainable urban water management that adapts to the impacts of climate change and climatic variations was difficult to define and measure, and there is no simple solution for this. Relating to water supply-side and demand-side measures, the participants suggested both water supply-side and demand-side measures should be considered holistically, water demand-side measures were perceived to be more important and reliable than the water supply-side measures.

WDM policies are generally subdivided into two subcategories including pricing-based WDM and non-pricing WDM. In this paper, WDM policies are subdivided into three major categories including pricing-based WDM, non-pricing based WDM, and emergency WDM. Emergency WDM policies include water restrictions, intermittent water supply and other emergency combinations of pricing and non-price based WDM policies. Although raising public awareness and education programs is a non-pricing based WDM policy in theory, it was also perceived by the water practitioners as a critical element for pricing-based WDM tools to be successful. Emergency WDM policy including the impacts of water restrictions depend on the success of public education and campaigning programs. Although water restriction is a non-price-based WDM policy in theory, it is primarily applied during water crisis events, and sometimes both pricing and non-price based WDM policies are applied as part of an emergency WDM response.

Although water-professionals perceive pricing-based WDM as the most effective tool (if implemented) to reduce water consumption in the case study region, the selected regional cities were primarily dependent on non-pricing based WDM strategies to achieve their reductions in water consumption. There were no major changes in water pricing structure in the region in the last 10 years, and water price in the study region is notably cheaper than in large metropolitan cities. (Mackay Regional Council MRC 2022c; Queensland Government QG 2022; QLD URban Utilities QUU 2022; Sydney Water. SA 2022; Townsville City Council. TCC 2022b; Water Corporations. WC 2022) This is potentially one of the critical reasons why the local urban water professionals believe that pricing-based WDM will be the most effective WDM tool in the region, if implemented. It appears there is a tendency to resist water price increases due to regional context, economic consequence, community backlash, local political interests, and short-term gains. In the existing literature, despite research on the effectiveness of different WDM policies, the outcomes are found to vary, and in some cases, the results are contradictory. In the greater Brisbane area (southeast part of Queensland, Australia) major intervention drives that focused on residential water conservation such as water restriction, public education and awareness, and rebates for water-efficient devices caused a 50% reduction in water demand during the millennium drought event that occurred between 2004 and 2009 (Queensland Water Commission 2010). In 2008, when water restrictions were relaxed in Brisbane, a notable decrease in water use (per capita) was noted compared to water use in 2004 (Queensland Water Commission 2010). Stavenhagen, Buurman, and Tortajada (2018) studied 13 different WDM policies in Europe and found that technological innovation in water network maintenance is the most effective measure for water conservation. In addition, they concluded that water regulations and restrictions, raising public awareness and education campaigns, and water-saving technologies play a critical role in water conservation. Appropriate water pricing policy is essential for sustainable water supply to the community as it also allows for cost recovery (Sahin, Bertone, and Beal 2017). Although many research reports have found pricing-based WDM to be the least effective for water conservation (Lu, Deller, and Hviid 2019; Tortajada et al. 2019), some authors have concluded otherwise (Mansur and Olmstead 2012 ; March & Sauri, 2010). It is important to conduct case-study-based research and investigations to develop a WDM strategy suitable for a specific region. One of the key findings of this paper is that water-professionals do not have a free hand to develop and implement WDM policies based on their engineering judgements and perceptions as they work under multiple constraints and challenges. In many cases, decisions on WDM are being taken considering local challenges, economic consequences, community attitudes, local political interests, and short-term gains.

Availability of surface water depends on climatic parameters including climate change and climatic variations. The case-study region is dependent on surface water resources for its day-to-day water needs. This can be one of the key reasons why the water practitioners perceive water demand-side adaptation measures as more reliable and important than the water supply-side measures for the region when it comes to climate change adaptation to achieve long-term UWS. Regional cities such as Townsville, Cairns and Mackay have unique regional challenges including regional context, lack of political attention and the resulting lack of funding to develop expensive water infrastructure and a traditional community base who are fond of cheap water resources. Although the interview participants strongly support a detailed water augmentation plan to suit local needs and challenges, water supply sources such as desalination plants are not considered a viable option due to high costs associated with their development and maintenance. A similar kind of result has been reported from other regions of the world (Fragkou and McEvoy 2016; McEvoy 2014). However, it needs to be noted that both desalination plants and water reuse schemes are gaining popularity in larger metropolitan cities of Australia, potentially due to the adequacy of funding and greater political interests. (Elsaliby et al. 2009; Radcliffe & Page 2020) Although water recycling and reuse is considered one of the most viable alternative water resources in the face of climate change, it needs to be noted that the local community is not in a position to accept recycled water for drinking purposes even if it is treated to a world-class standard, and it is preferred for non-potable purposes. A similar trend has also been observed in some other parts of the world (Moshtagh and Mohsenpour 2019; Ricart et al. 2021).

Among the water-resource options, surface water is perceived by the water practitioners to remain a high-priority water resource for the region, although climate-change is projected to make this resource more vulnerable in the area. The seasonal variation in the available surface water resource is perceived as a major issue rather than long-term depletion of surface water resource in the study region, although depletion of water resources is projected in some parts of the region (; QG, 2022). It implies that although the interview participants were found to be aware of climate change risks and the importance of climate change adaptation, it has not been considered as an important selection criterion when long-term water supply solutions are investigated. Water supply augmentation and WDM works are normally done to satisfy immediate needs and for long-term growth of the region rather than a specific reason such as climate risks.

6. Limitations and suggestions

One of the key limitations of this study is that the perceptions of water experts can vary considerably, and smaller numbers of interview participants also mean that the outcome of this study may not reflect in the larger context. The research findings can be concluded to be suggestive in nature. However, it needs to be noted that as the study area consists of regional urban centres, the organisations are expected to have a smaller number of water professionals employed compared to the large metropolitan cities. Twenty urban water professionals can still be considered adequate for this research given the disparity in employee numbers working in regional centres vs metropolitan cities.

Although the paper identified different climate change adaptation elements, water supply and demand-side measures to achieve long-term UWS, the interview study outlined in this article primarily targets the participants’ perceptions on the adequacy of overall climate change adaptation practice and the importance of different water-supply and demand-side measures to achieve long-term water security despite climate change and climatic variation. The study does not target all the elements of climate change adaptation identified from the literature review, rather it focuses on the perceptions of the overall implementation of climate change adaptation, different water supply, and demand-side measures. Further research is required on how to implement climate change adaptation, barriers and enablers for local authorities who manage and plan for urban water.

Another limitation of this research is that it fundamentally targets the perceptions and priorities of the urban water professionals in a regional context. Although the paper briefly outlines the actions undertaken by the regional urban water authorities, it does not study the details of the water-supply and water demand-side actions currently being undertaken in the study region. To achieve a more representative understanding, it is highly important that a large-scale research study be conducted.

7. Conclusions

Climate change impacts are being felt all around the world, and adaptation actions are urgently needed in the urban water sector as climate change will inevitably cause urban water scarcity. Water scarcity can be dealt with either using water supply measures and/or water demand measures. Water professionals are continuously challenged to protect the available usable water in a region for the long term and manage different constraints and limitations associated with it.

In this paper, the perceptions of the urban water professionals in the tropical urban region of Queensland, Australia, have been studied to understand their viewpoints on the different water supply and demand-side measures in order to achieve long-term UWS in the face of climate change risks. To cope with water supply shortages in the changing climate, long- and short-term strategies are suggested to be developed for the different water authorities based on the local climatic and geographic conditions. Among the water supply resource options, surface water resource is perceived to remain a high priority water resource for the region. However, surface water resources are more uncertain and vulnerable in the study area. Both water supply-side and demand-side measures were recommended to be considered holistically by the respondents, water demand-side measures were perceived to be more important and reliable than the water supply-side measures.

It is interesting to note that pricing-based WDM policies were preferred by the participants to reduce water consumption in the region in order to achieve a balance between water supply and demand in the face of climate change even though non-pricing-based WDM policies were primarily implemented in the region. Climate-change risks have rarely been considered as a selection-criterion when long-term water solutions were investigated by the water-practitioners and in most cases water supply augmentation and WDM works are done to satisfy the immediate needs of a water organisation and also for long-term growth of the region.

CRediT authorship contribution statement

Rahul Ray Biswas: Conceptualisation, Data Collection, Formal analysis, Investigation, Writing – Original Draft, Writing – Review & Editing. Raj Sharma: Writing – Review & Editing, Supervision. Yeboah Gyasi Agyei: Writing – Review & Editing, Supervision. Anisur Rahman: Writing – Review & Editing, Supervision.

Acknowledgements

This research work was supported by the Australian Government Research Training Program Scholarship provided by the Department of Education, Skills and Employment, Government of Australia. We are grateful to the regional urban water professionals who participated in the interviews that yielded valuable information. Valuable and constructive comments by the anonymous reviewers are greatly acknowledged.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Funding

The work was supported by the Australian Government Research Training Program [RTP (Research Training Program) Scholarship].

APPENDIX APPENDIX A:

Interview participants

Table

Interviewee Code	Position and employment department
PE1	Planning engineer (Infrastructure asset management & planning)
PE2	Planning engineer (Infrastructure asset management & planning)
PE3	Planning engineer (Planning services)
PE4	Planning engineer (Planning services)
PE5	Planning engineer (Development planning, policy, and approval)
PE6	Planning engineer (Development planning, policy, and approval)
WE1	Water expert (Infrastructure asset management & planning)
WE2	Water expert (Infrastructure asset management & planning)
WE3	Water expert (Policy development and implementation)
WE4	Water expert (Policy development and implementation)
WE5	Water expert (Policy development and implementation)
SE1	Sustainability expert (Policy development and implementation)
SE2	Sustainability expert (Policy development and implementation)
SE3	Sustainability expert ((Infrastructure asset management & planning))
SE4	Sustainability expert (Policy development and implementation)
PO1	Planning officer (Policy development and implementation)
PO2	Planning officer (Planning services)
PO3	Planning officer (Planning services)
PO4	Planning officer (Development planning, policy, and approval)
PO5	Planning officer (Development planning, policy, and approval)

APPENDIX B:

Interview questions

Table

No.	Description
1	Tell us about the current implementation of climate change adaptation practice in urban water sector?
2	Among the water supply-side and demand-side measures what options the local urban water authorities should explore more and implement to achieve long-term urban water supply security in the face of climate change and climatic variations? How, why or why not?
3	Among the water resource options, what options the water authorities should explore more and implement to achieve water supply security in the face of climate change? Why or why not?
4	Further ‘How’ or ‘Why’ type questions to get better understandings on the perception of the regional urban water professionals.