Urban Water Demand Management Research Articles

Social perception on rainwater harvesting and wastewater reuse: Opportunities and challenges of a fast-growing township in Dhaka

Dhaka, the only megacity of Bangladesh is facing water stress due to unplanned urbanization and lack of sustainable water management practices. The two important components of Integrated Urban Water Management, i.e., rainwater harvesting (RWH) and wastewater reuse are hardly practiced in Dhaka. A new township is growing in Dhaka to meet the dwelling needs of middle-income groups with the opportunities to integrate both the systems. However, the integration is either missing or lacks considerations of sustainability. This study explores the perceptions of 256 respondents (beneficiary and functionary) to ascertain the opportunities and challenges of integration of RWH and wastewater of the growing township using structured questionnaires. The awareness, level of knowledge, willingness and key necessities have been explored through the questions. The general awareness level on RWH and wastewater reuse ranges between 30% - 62% and 34%- 42% respectively for different age groups. Around 70% of the respondents lack knowledge on regulatory aspects of its implementation. Apart from economic insights, the perception reveals around 64% willingness towards its integration for urban water demand management. Complete awareness generation, enforcement of compliance and streamlining the process of integration are the key imperatives to offset the non-adoption of both components.

An integrated approach to decision-making variables on urban water systems using an urban water use (UWU) decision-support tool

In response to pressing global challenges like climate change, rapid population growth, and an urgent need for sustainable infrastructure, cities face an immediate and crucial necessity to transition swiftly toward an integrated approach to managing urban water resources. This shift is not merely an option but an imperative, driven by the rapidly evolving urban landscape. In addressing this imperative, a crucial decision support tool that has emerged as an asset in the domain of urban water planning and management is the Urban Water Use (UWU) tool. This tool offers an integrated approach for strategic planning, promoting urban water conservation and environmental health through the investigation of interventions in urban infrastructure under different scenarios. In this study, the latest version of this UWU tool was deployed in a case study conducted in Almirante Tamandaré, Brazil. The objective was to evaluate how an integrated decision-making approach concerning urban water systems influences the efficiency and effectiveness of interventions, ultimately contributing to achieve widespread adoption, accessibility, and relevance of urban water services. The refined UWU tool evaluates a spectrum of measures across diverse scenarios, incorporating various drivers, focusing on the stakeholders' visions for the locality. These visions are composed of sustainability indicators, specifying different sets of target values and importance weights for each indicator. The approach followed in this study demonstrates how the effectiveness indexes can vary based on stakeholders' perception. Measures under Water Sensitive Urban Design and Water Demand Management strategies were deployed to simulate the response of urban water systems under three distinct scenarios, embracing the complexities of social dynamics and of climate change. The findings of the study emphasize that realizing a desired vision through selected measures relies significantly on the adoption of an integrated approach within the decision-making process. The stakeholders' perception of how indicators should be weighted while defining the vision was found to significantly impact the effectiveness range of these measures.

Climate Change Impacts and Environmental and Water use Behaviors, Beliefs and Perceptions

This paper presents research conducted on urban home water use behavior as a response demand mitigation strategy to reduce domestic water consumption in SA. The paper presents results of urban home residents’ attitudes, behavior and perceptions towards their water consumption in a search for ways in which domestic demand for water may be substantially reduced. The analysis reflects the water use behavior and perceptions of urban dwellers in a period where water use rationing and restrictions are in place in parts of SA, therefore water scarcity is an important public crisis issue.
 The research has brought to the fore the complexity of the forces shaping water demand and use in the context of the socio-demographic composition of homes residing in different types of dwellings, as well as the cultural, behavioral and attitudinal aspects of water consumption in city of Durban. The essential questions driving the research was what extent the two key dimensions of urban structure do, i.e. built form and the socio-behavioral characteristics of home water use, influence the pattern of water consumption. Additionally, the study ascertained the extent to which urban water users understood water-saving practices and the need to conserve this precious natural resource whilst also investigating the extent that the public believed were the most effective water-saving habits, interventions and communication methods to support reduced water consumption at a home level. In so doing, the study findings have aimed to inform public policy on ways to reduce consumption and identify alternative and complimentary ways to address the urban water conservation and demand management planning.

The impact of virtual water trade on urban water scarcity: A nested MRIO analysis of Yangtze River Delta cities in China

With the aim of balancing and reducing the inflows and outflows of water between cities, urban water management is critical in China's goal of alleviating water stress and promoting water sustainability. In facilitating further understanding of the supply and demand of urban water resources, analysis of the direct and indirect water profiles of cities is considerably beneficial. In the present study, by compiling a nested multi-regional input output table, for the first time, the city-level water footprints for 26 Yangtze River Delta cities were estimated and the virtual water trade patterns at home and abroad were investigated as well as the impact thereof on urban water resource stress. The results show that the total water footprint of the urban agglomeration was 114.8 Gm3 in 2012 and over 50% of the water footprint could be attributed to virtual water inflows which were mainly shaped by agriculture and light industry. The net virtual water inflow was 9.0 Gm3, indicating that virtual water trade alleviates the shortage of water resources in the region. At the city level, richer cities tended to have a higher water footprint by importing large amounts of virtual water to satisfy their higher requirements for the quality of life and larger household consumption. However, less developed water-abundant cities had more water footprint from infrastructure construction, and exported considerable virtual water to other cities, thereby exacerbating local water stress of these cities. The inter-city virtual water flows within the Yangtze River Delta were contributed by multiple industry sectors and the inequality of urban water scarcity among cities therein has been alleviated to a certain extent. Our results highlight the importance of simultaneously considering both the volume and the impact of water use in virtual water trade analyses. The present authors conclude that attention needs to urgently shift from supply-oriented water management to urban water demand management.

Systems Thinking for Planning Sustainable Desert Agriculture Systems with Saline Groundwater Irrigation: A Review

Agricultural land expansion is a solution to address global food security challenges in the context of climate change. However, the sustainability of expansion in arid countries is difficult because of scarce surface water resources, groundwater salinity, and the health of salt-affected soil. Developing expansion and sustainability plans for agriculture requires systems thinking, considering the complex feedback interactions between saline groundwater, salt-affected soil, plant growth, freshwater mixing with saline groundwater, irrigation systems, and the application of soil amendments to alleviate the salinity impacts. This study presents an extensive literature review on the effects of salinity on soil and plant health, the constraints and opportunities for sustainable agriculture in Egypt, and a systems thinking approach to the feedback interactions between saline water, salt-affected soil, and the application of soil amendments to achieve required crop yields. Insights and strategies are discussed, including a system-dynamics-based decision model, irrigation systems with diversified and decentralized water sources, urban water demand management, energy availability, smart irrigation systems, and active participation of stakeholders to achieve sustainable agriculture under climate and socioeconomic changes. The insights are expected to encourage stakeholders and academic communities in the water, agriculture, and related food security sectors to develop a quantitative and systematic decision-making framework for sustainable agriculture systems in arid regions.

Promoting the adoption of residential water conservation behaviors as a preventive policy to sustainable urban water management

As concerning with water insecurity driven by water scarcity threatens the lives and livelihoods of humanity worldwide, urban water demand management is focused on promoting residential water conservation behaviors (WCBs) as a critical policy response to water scarcity. However, urban water conservation initiatives cannot be successful unless households involve in residential WCBs voluntarily by adopting water curtailment and/or water-efficiency actions. Thus, understanding motivations and mechanisms underlying accepting these two types of WCBs and interpreting their distinctions are primary policy considerations to make sustainable water consumption behaviors. Hence, the purpose of this research was twofold: (1) To explore intentions to household adoption of water curtailment and water-efficiency actions, key corresponding determinants, and distinctions between them; and (2) To evaluate the capability and robustness of the Health Belief Model (HBM) to explain residential WCBs. The present research design was a cross-sectional survey conducted in Tehran, Iran. The outcomes from structural equation modeling indicated that: (1) Water curtailment intention was solely determined by self-efficacy and perceived benefits; (2) In addition to self-efficacy and perceived benefits, perceived severity, cues to action, and perceived barriers were significantly related to water-efficiency intention; (3) While only perceived susceptibility was not a significant determinant for water-efficiency intention, perceived susceptibility, perceived severity, perceived barriers, and cues to action could not significantly explain water curtailment intention; (4) Self-efficacy also emerged as the strongest predictive variable behind intentions to adopt both WCBs; (5) The perceived barriers had a negative significant relationship only with water-efficiency intention; and (6) The HBM could explain 72% and 61% of the variance in households’ intentions to adopt water curtailment and water-efficiency actions, respectively. These outcomes supported that the HBM could propose a reliable and practical heuristic theoretical framework to predict residential WCBs. Moreover, the findings confirmed significant differences among socio-psychological factors behind intentions to household adoption of both WCBs, which need to be addressed. The research results introduced numerous implications from theoretical and policy standpoints for improving residential WCBs.

Water permits trading framework for urban water demand management based on smart metering

Water rights trading is commonly used as a means of water resources reallocation between different water use sectors or between different end-users within the same sector. No studies, however, were reported on water rights trading from residential water use to other sectors. The primary reasons include the ambiguous definition of residents’ water rights and lack of real-time information about water consumption. This study presents a domestic-industrial water permits trading framework for urban water demand management. The framework is applied to the case study of Dalian demonstrating its feasibility theoretically and technologically from the perspective of the whole city and typical demonstration areas. The finding obtained shows that the tradable water volume accounts for 13.72% of the total residential water use, brings a profit of 91.05 million yuan to the residents, and saves 56.67 million yuan of water resources costs for industry users. The increase in water prices for consumption through tiered pricing can raise the tradable volume to 16.10%. Furthermore, a trading platform based on WeChat is developed to completely materialize the entire water permits trading process according to the real-time water consumption data collected from smart water meters. This study shows that the water permits trading between urban domestic-industrial sectors is an effective means of redistributing urban water resources to improve economic benefits while ensuring urban water supply security.

How can socio-psychological factors be related to water-efficiency intention and behaviors among Iranian residential water consumers?

Water security while facing a growing water demand and decreasing supply has become a vital issue in urban areas, especially in arid and semi-arid regions. Considering households’ potential for significant water saving, residential water conservation has become the main component of the future sustainable water supply. To encourage households to engage in water conservation behaviors voluntarily, it is crucial to recognize and consider the socio-psychological factors influencing acceptance of such behaviors, including intention, normative aspects, and so on, because it can lead to the implementation of effective policies in urban water demand management. The main goal of the current research was to investigate the prerequisites and determinants of household water-efficiency intention and behaviors among Iranian citizens. To that end, the current research was based on the theory of planned behavior (TPB) and extended TPB by adding three new variables: moral norm, perceived risk, and familiarity to the theoretical framework. A questionnaire survey method (N = 820) was used to collect data from Tehran citizens. Structural equation modeling revealed that intention to adopt water-efficiency behaviors was predicted by attitude, perceived behavioral control (the most potent predictor), moral norm, perceived risk, and familiarity. Water-efficiency behaviors were predicted by intention, perceived behavioral control, and familiarity (the strongest determinant). Perceived risk was also a substantial determinant for attitude and moral norm. The findings indicated that both TPB and extended TPB frameworks are useful and practical tools for explaining the relationship between socio-psychological factors and water-efficiency intention and behaviors. Moreover, after the inclusion of the three new variables of moral norm, perceived risk, and familiarity in the original TPB, its predictive power for intention and behaviors increased up to 9% and 21%, respectively. According to the results, implications for improving and promoting water-efficiency intention and behaviors among households and suggestions for relevant future studies are proposed.

Response of residential water demand to dynamic pricing: Evidence from an online experiment

Abstract Urban water demand management is key to water supply sustainability in high-density, water-stressed areas throughout the world, and emerging technologies could transform it. In particular, smart metering could allow for conserving water by dynamically changing prices to reflect water scarcity and supply cost variability. Yet, little is known on end-users’ reaction to short-term price changes, an essential determinant of the effectiveness and acceptability of dynamic water pricing. This paper reports on the design and results of an online experiment that measures end-users’ water consumption decisions when confronted with time-varying prices, and investigates the interaction between pricing and water scarcity awareness. We design a series of treatments where players must indicate their shower length given different water prices, price variations, and scarcity scenarios. Beyond corroborating the theory that higher prices lower usage, the experiment finds evidence of a dynamic pricing effect: users respond more strongly to a given price if they have been exposed to a lower price before. This suggests short-term residential price increases could be effective at boosting water conservation.

Dynamic optimization of input production factors for urban industrial water supply and demand management

To help minimize urban industrial water consumption and realize the goal of a water-saving society, this paper develops a method for the dynamic optimization of the input production factors in an urban industrial water supply model. A negative exponential curve describes the urban industrial water consumption per Yuan of urban industrial value added, the latter being described by a Gompertz curve. The product of the two describes the urban industrial water demand. The production function of urban industrial water supply is expressed by the fixed substitution proportional production function. Taking investment and labor input as control variables, the system goal is to balance of industrial water supply and demand. The time-varying model can not only solve the stable state problem for infinite time horizon, but also the transient problem for finite time horizon. Taking Jiangsu province in eastern China as an example, the applicability of the method was investigated under different parameter combinations. The simulation results show its effectiveness in these cases. In the earlier period, meeting balance requirements is easier using the straight-line capital depreciation method. In the later period, the fixed rate on declining balance method allows to meet the requirements more easily. In general, it is easier to achieve the goal by choosing a smaller and feasible weight matrix coefficient of the control variables.

Estimation of dynamic water demand function: the case of Istanbul

This paper empirically examines the determinants of water demand in the megacity of Istanbul, Turkey, using a dynamic framework. An autoregressive distributed lag model is developed to estimate both short-run and long-run water price elasticities using aggregated monthly water consumption data. Empirical analysis reveals that a long-run stable demand relationship exists between water consumption and water price along with several non-price variables. Results indicate that water demand in Istanbul is price-inelastic with an estimated price elasticity of –0.15 in the short run, and around in the long run. Empirical results also suggest that the block increasing tariff regime is more effective in urban water demand management than the single volumetric price regime. Overall, the empirical findings of this study imply that price can potentially be used as an effective policy tool for water demand management in Istanbul.

Ecosystem Service Impacts of Urban Water Supply and Demand Management

Utilities face the challenge of enhancing long-term water security while minimising undesirable economic, social and environmental impacts of supply and demand management options. This paper provides an example of how the ecosystem services concept can be used to enumerate and organise broad impacts of water supply options. A case study of Adelaide, South Australia, is used to examine costs and benefits associated with different sources of water and source-water mix scenarios. Ecosystem service impacts are estimated using estimates from the literature. Seven water supply and demand management options are considered for Adelaide: 1) the River Murray, 2) Mt. Lofty Ranges catchments, 3) wastewater reuse, 4) desalination, 5) stormwater harvesting, 6) groundwater and 7) water conservation. The largest costs are associated with sourcing water from conservation measures such as water restrictions on outdoor watering estimated at $1.87/kL. Salinity damage costs associated with residential uses are estimated at up to $1.54/kL. Salinity damage costs of wastewater reuse were estimated at $1.16/kL. The largest benefit is coastal amenity services associated with stormwater harvesting and treatment estimated at $1.03/kL. Results show that there is a trade-off between financial costs and ecosystem services impacts with source-water mix scenarios with the highest ecosystem services cost having the lowest financial O&M cost and vice versa. This highlights the importance of taking ecosystem services into account when evaluating water supply options.

Assessment of Sustainability of Urban Water Supply and Demand Management Options: A Comprehensive Approach

A comprehensive evaluation framework that can assess a wide range of water supply and demand management policy options in terms of economic, social, environmental, risk-based, and functional performance is crucial to ascertain their level of sustainability. However, such a detailed, generic, and holistic policy evaluation framework is not found in the literature. This paper reviews studies to evaluate water supply and/or demand management options conducted during 2000–2016. Primarily, the paper reviews the evaluation criteria used by different studies for decision making given their significant difference and the importance of a comprehensive set of criteria to complete a rigorous evaluation. In addition, a comprehensive set of water supply and demand management options are not considered together for a comparative assessment to prioritise best options for a certain area and time. Further, performance of these options needs to be evaluated for a range of uncertainties arising from changes of spatial and temporal variables of the system. While this paper highlights the important aspects that need to be included in a comprehensive policy evaluation framework, available studies collectively present a rich set of information to support it.

Intelligent autonomous system for residential water end use classification: Autoflow

Over half of the world's population will live in urban areas in the next decade, which will impose significant pressure on water security. The advanced management of water resources and their consumption is pivotal to maintaining a sustainable water future. To contribute to this goal, the aim of this study was to develop an autonomous and intelligent system for residential water end-use classification that could interface with customers and water business managers via a user-friendly web-based application. Water flow data collected directly from smart water metres connected to dwellings includes both single (e.g., a shower event occurring alone) and combined (i.e., an event that comprises several overlapping single events) water end use events. The authors recently developed an intelligent application called Autoflow which served as a prototype tool to solve the complex problem of autonomously categorising residential water consumption data into a registry of single and combined events. However, this first prototype application achieved overall recognition accuracy of 85%, which is not sufficient for a commercial application. To improve this accuracy level, a larger dataset consisting of over 82,000 events from over 500 homes in Melbourne and South-east Queensland, Australia, were employed to derive a new single event recognition method employing a hybrid combination of Hidden Markov Model (HMM), Artificial Neural Networks (ANN) and the Dynamic Time Warping (DTW) algorithm. The classified single event registry was then used as the foundations of a sophisticated hybrid ANN–HMM combined event disaggregation module, which was able to strip apart concurrently occurring end use events. The new hybrid model's recognition accuracy ranged from 85.9% to 96.1% for single events and 81.8–91.5% for combined event disaggregation, which was a 4.9% and 8.0% improvement, respectively, when compared to the first prototype model. The developed Autoflow tool has far-reaching implications for enhanced urban water demand planning and management, sustained customer behaviour change through more granular water conservation awareness, and better customer satisfaction with water utility providers.

Water and the city: exploring links between urban growth and water demand management

Urban water management is currently understood as a socio-technical problem, including both technologies and engineering interventions as well as socioeconomic dimensions and contexts vis-à-vis both end users and institutions. In this framework, perhaps the most important driver of urban water demand, at the intersection between engineering, social and economic domains, is urban growth. This paper examines aspects of the interplay between the dynamics of urban growth and the urban water cycle. Specifically, a cellular automata urban growth model is re-engineered to provide growth patterns at the level of detail needed by an urban water cycle model. The resulting toolkit is able to simulate spatial changes in urban areas while simultaneously estimating their water demand impact under different water demand management scenarios, with an emphasis on distributed technologies whose applicability depends on urban form. The method and tools are tested in the case study of Mesogeia, Greece, and conclusions are drawn, regarding both the performance of the urban growth model and the effectiveness of different urban water management practices.

Analytical optimization of demand management strategies across all urban water use sectors

AbstractAn effective urban water demand management program can greatly influence both peak and average demand and therefore long‐term water supply and infrastructure planning. Although a theoretical framework for evaluating residential indoor demand management has been well established, little has been done to evaluate other water use sectors such as residential irrigation in a compatible manner for integrating these results into an overall solution. This paper presents a systematic procedure to evaluate the optimal blend of single family residential irrigation demand management strategies to achieve a specified goal based on performance functions derived from parcel level tax assessor's data linked to customer level monthly water billing data. This framework is then generalized to apply to any urban water sector, as exponential functions can be fit to all resulting cumulative water savings functions. Two alternative formulations are presented: maximize net benefits, or minimize total costs subject to satisfying a target water savings. Explicit analytical solutions are presented for both formulations based on appropriate exponential best fits of performance functions. A direct result of this solution is the dual variable which represents the marginal cost of water saved at a specified target water savings goal. A case study of 16,303 single family irrigators in Gainesville Regional Utilities utilizing high quality tax assessor and monthly billing data along with parcel level GIS data provide an illustrative example of these techniques. Spatial clustering of targeted homes can be easily performed in GIS to identify priority demand management areas.

Maintaining the Common Pool: Voluntary Water Conservation in Response to Varying Scarcity

Studies of voluntary conservation response to changing information about an environmental problem have traditionally been synonymous with studies of information campaign effectiveness. As such, they have not been able to capture the response to actual changes in the environment. This paper takes a novel approach to identifying voluntary conservation by studying the impact of changing storage levels on urban water usage in the context of a prolonged drought and a highly ’water aware’ community. Our results suggest that voluntary conservation increases substantially when water is scarce and the public value of the savings is greatest. We discuss the implications of these findings for our understanding of environmental information campaigns in general, and urban water demand management in particular.

Water demand management: review of literature and comparison in South-East Asia

The present paper reviews the literature on urban water demand management and compares practices in South-East Asia. Existing literature is mostly from developed economies and is concerned mainly with elasticity studies, which are not relevant to developing countries because their main problem is non-revenue water. Cities in South-East Asia employ both price and non-price mechanisms to regulate demand. Price mechanisms include increasing block tariffs, fixed, volumetric, raw water, and conservancy charges, rebates, cross-subsidies and periodic rebasing. Non-price mechanisms such as management, engineering and regulatory mechanisms, as well as public education and community involvement, play important roles. More studies are needed to establish their efficacy and cost-effectiveness.

Maintaining the Common Pool: Voluntary Water Conservation in Response to Increasing Scarcity

Studies of voluntary conservation response to changing information about an environmental problem have traditionally been synonymous with studies of information campaign effectiveness. As such, they have not been able to capture the response to actual changes in the environment. This paper takes a novel approach to identifying voluntary conservation by studying the impact of changing storage levels on urban water usage in the context of a prolonged drought and a highly ‘water aware’ community. Our results suggest that voluntary conservation increases substantially when water is scarce and the public value of the savings is greatest. We discuss the implications of these findings for our understanding of environmental information campaigns in general, and urban water demand management in particular.

An experimental test of voluntary strategies to promote urban water demand management

In light of the current and future threats to global water security the current research focuses on trialing interventions to promote urban water conservation. We report an experimental study designed to test the long-term impact of three different interventions on household water consumption in South East Queensland. Participants from 221 households were recruited and completed an initial survey, and their houses were fitted with smart water meters which measured total water usage at 5 s intervals. Households were allocated into one of four conditions: a control group and three interventions groups (water saving information alone, information plus a descriptive norm manipulation, and information plus tailored end-user feedback). The study is the first to use smart water metering technology as a tool for behaviour change as well as a way to test the effectiveness of demand management interventions. Growth curve modelling revealed that compared to the control, the three intervention groups all showed reduced levels of household consumption (an average reduction of 11.3 L per person per day) over the course of the interventions, and for some months afterwards. All interventions led to significant water savings, but long-term household usage data showed that in all cases, the reduction in water use resulting from the interventions eventually dissipated, with water consumption returning to pre-intervention levels after approximately 12 months. Implications for water demand management programs are discussed.