Policy design tool for managing indoor residential water demand in water-scarce regions

In view of population growth; climate change; and economic evolution, water resources in numerous parts of the world have reached their natural capacities. Consequently, the ability of many countries to grow; meet the basic needs of inhabitants; and protect the environment will be endangered like never before unless water resources are smartly handled and managed. In the past few decades, many developed and developing countries have suffered from water scarcity, and more are certain to follow. The water security dilemma is much more challenging in developing countries. Water utilities have had to follow regulatory plans to manage demand on water resources. Not surprisingly, demand on residential water is deemed to be the most critical sector over other competing sectors. Despite the vast amount of research on residential water demand management, little is known about the willingness of consumers to participate in demand management plans. This has been attributed to the complex nature of modelling consumers’ participatory actions, leaving policy makers with unexpected outcomes from their demand management plans. In order to overcome this challenge and enable policy makers to understand the complex interactions between water consumers, a comprehensive tool is needed to account for the heterogeneity of water consumers without compromising the complex nature of water systems. The development and application of the comprehensive tool is demonstrated using Amman, the capital city of the Kingdom of Jordan as a case study. This research addresses water supply and demand from a complex adaptive systems’ perspective. The primary objectives of this investigation are to: (1) develop a model for consumer’s awareness of water conservation that is capable of addressing the role of individual attributes in participating in demand management policies; (2) develop a complex adaptive systems framework for residential water supply and demand to capture the interactions between consumers and policy makers; and (3) develop a model to capture the possible impacts of the non-piped water source on efforts to manage water consumption. First, an econometric model is constructed that explains the extent to which consumers’ attributes affect their participation in demand management activities. Participation in water conservation plans can be achieved through installation of efficient plumbing fixtures and the adoption of conservative water-use habits. Thus, correlation between efficient fixtures and habits should be considered. Second, a complex adaptive systems framework is developed to facilitate the application of different demand management policies on residential water consumers. The framework is capable of capturing the complex interactions between consumers themselves and the policy maker (the entity in charge of applying demand management policies while supplying piped water), while explicitly considering their heterogeneity. This bottom-up approach can forecast the diffusion of efficient fixtures and conservative habits. Third, a system dynamics model is built to investigate the feedbacks between different sources of supply and demand management efforts. This model will examine the possible interactions between water availability and consumers’ participation in demand management by predicting the compensatory actions taken by consumers to reduce their water shortage. The primary research developments presented in this work hold strong potential to advance current tools of residential water demand management through: (1) improving the understanding of what lies behind consumers’ participation in demand management policies; (2) explicit accounting for the correlation between the adoption of water-saving fixtures and conservative water use habits; (3) addressing the heterogeneity of water consumers and thus capturing the complexity of demand management; and (4) reducing uncertainty in estimating the effectiveness of different demand management policies by capturing the influence of mixed sources of supply on water demand