Sustainable Solutions for Urban Water Security

Water is of vital and critical importance to ecosystems and human societies. Issues like urbanization, population growth, socioeconomic change, evolving energy needs and climate change have put unprecedented pressure on utilization of freshwater resources. It is argued that achieving water security is the key to sustainable development. The focal point of water security evolves from ensuring reliable access of enough safe water for every person at an affordable price to lead a healthy and productive life along with maintaining the water-related ecosystem services for future generations. Although total water demand at global scale is well within available water resources, the shortages prevail at spatial and temporal scales. The constraints on water availability and water quality threaten secure access to water resources for different uses. Despite recent progress in developing new strategies, practices and technologies for water resource management, their dissemination and implementation have been limited. The chapter focuses on urban water security and their connections with practical issues dealing with real-world situations. This chapter sets the stage to understand the evolution of urban water security, its challenges and ways to achieve sustainable water management. A comprehensive sustainable approach to address water security challenges requires connecting social, economic and environmental systems at multiple scales. This chapter strives to capture the persistently changing dimensions and new paradigms of water security providing a holistic view including wide range of sustainable solutions to address the water challenges.

Water security is a new concept for the sustainable water management. Rapid urbanization and climate change have become a burden for water security managers. It is important to understand and investigate various challenges and impacts of global environment changes for managing water-related problems like frequent urban floods; groundwater water depletion; surface and groundwater pollution; land subsidence and aquatic ecosystems. Urbanization leads to more impervious surface causing increased storm runoff and decreased groundwater recharge resulting in greater floods and groundwater table depletion. Similarly, climate change is reported for alteration of rainfall pattern with more extreme rainfall events and longer dry days resulting in greater floods and lower groundwater table. Therefore, haphazard urbanization, climate change, population growth and change in lifestyle have badly affected urban water environment. In many cases, urbanization rate is quite higher in comparison to capacity of local government which is mainly engaged in development and construction of water infrastructures like water supply and sanitation system, stormwater drainage and flood management system. This chapter is focused on various global environmental changes with focus on urbanization and climate change and their implications on urban water security. Case studies have been included for better illustrations.

The urban water providers are confronted with the multiple challenges of limited water availability, inadequate water quality and rising living standards, resulting in growing water demands. The inefficient water supply systems and negative impacts of changing climate are threatening local water resource availability and increasing risks of water-related disasters in developing countries. Therefore, providing adequate quantity and quality of potable water presents a complex challenge for urban water providers. In developing countries, coping with the growing water demand is based on conventional water supply-driven approaches. The traditional methods of augmenting water supply using engineering practices are considered short-term solutions. In this background, the chapter argued in favor of the transition from supply-oriented management toward demand-oriented management. Urban water demand management emphasizes the ‘demand over supply’ approach and effectively manages the demand determinants. The strategies defined as classified as supply-side and demand-side solutions to reduce water demands. With the help of a case study (Kathmandu Valley, Nepal), the effectiveness of urban water management strategies is evaluated. The result showed that the strategies effectively reduce water demand, conserve local sources and increase water availability. It also plays a significant role in the transitioning of the conventional water supply system to an effective water management system.

Achieving water security through availability of sufficient water with good quality for all is the main agenda of the United Nation Sustainable Development Goals by the year 2030. The constraints on water availability and deteriorating water quality through global changes threaten secure access to water resources for different uses. Main drivers among these global changes, which are responsible for changes in hydrological cycle, are rapid urbanization, economic development, population burst, land use/land cover changes and climate changes. Effects of theses global changes can be easily seen through the impacts that water bodies bring to the society in the form of flooding and draught, and most important polluted water bodies result in unhygienic environment/ecosystem and health risks due to emerging pollutants. Henceforth, sustainable water resource management is necessary to achieve the goal of water secure future. Despite recent progress in developing new strategies, practices and technologies for water resource management, their dissemination and implementation have been limited. A comprehensive sustainable approach to address water security challenges requires connecting social, economic and environmental systems at multiple scales. This chapter aims to first depict the current situation about water and wastewater especially in Asian countries, followed by brief sketch about outreach and challenges of the existing technologies and policy intervention to achieve sustainable water resource management. Finally, with some successful case studies, this chapter tries to highlight the importance of transdisciplinary research activities, which can bring overhaul changes in policy interventions necessary ingredient for achieving water security.

Water security in urban areas is a highly challenging issue. Urban areas have caused dramatic changes in the freshwater environments by activities such as damming, channel modification, increase in impervious surfaces, disconnected waterways and increasing pollutants. Accordingly, this chapter argues for a landscape-based approach for water security through better human–nature connections with areas that are related with better urban water security. It is argued that wise management of urban water landscapes can enhance conditions that support water supply, habitat provision, natural sewage treatment and spaces for recreations and cognitive interactions among others. The chapter brings case studies from Japan, India and the Philippines for exemplifying key human–nature interactions that can ensure urban water environments through ecosystem-based land-use practices.

Water resources in urban areas are either approaching or exceeding the limits of sustainable use at alarming rates. Depletion of groundwater and increasing floods has become a common issue in rapidly developing urban areas. Therefore, improvement of present water management systems for managing water quality, while at the same time reducing hydro-meteorological disasters, and preserving natural environment in a sustainable manner is a priority that urban water managers should tackle. Accordingly, this chapter presents an overview of stormwater runoff management to guide future optimal stormwater runoff measures and management policies. The study provides commentary to assist policymakers and researchers in the field of stormwater management planning to understand the significance and role of remote sensing and GIS in designing optimal capture measures under the threat of future extreme events including the ones related to climate change. Community attitudes, which are influenced by a range of factors, including knowledge of urban water problem, are also considered. Additionally, the chapter also focuses on effects of different onsite facilities, including those for water harvesting, reuse, ponds and infiltration, are explored to establish adaptation strategies that restore water cycle and reduce climate change-induced flood and water scarcity on a catchment scale. The study brings real-world examples through case studies on Japanese, Vietnamese and Thai stormwater runoff management policies and measures to manage water scarcity and achieve water resiliency.

Global change processes like increasing population, haphazard urbanization and climate change have resulted huge pressure on natural resources. In this context, it is natural to think of how water cycle will be altered by such global change processes. Currently, more than half of the global population resides in urban areas, and thus, urban water security is of great concern. Hydrologic simulation models enable to assess various implications of the global change processes on water resources variables. Various hydrologic models are available for simulating the water resources variables. Each of the hydrologic models has some specific features. The hydrologic models are largely used for investigating impacts of urbanization and climate change on water resources variables like runoff, groundwater recharge, etc. Hydrologic models are categorized into various ways. Based on length of simulation time, a model can be of continuous or event-based type. Hydrologic models are also popularly classified as empirical, conceptual and physical types. Hydrologic simulation models require various data and tools which are available with different agencies. It is important to have easy access to such data and tools for the sustainable water management. Hydrologic modeling requires various kinds of spatial and temporal data for the model setup and prediction of water resources variables. Collection, analysis and integration of such spatial and temporal data with a hydrologic model is complex job. Remote sensing data and geographic information system can be easily linked with a hydrologic model and enable hydrologic simulations easier and reliable. This chapter discusses numerical modeling and simulations for the water management with focus on their types, applications, data access and spatial analysis tools.

Ineffective water governance is a significant factor in causing water insecurity and hampering the goal of sustainable development in developing countries. The water resources in South Asia are under increasing pressure from population growth, urbanization and industrial growth along with socioeconomic water demand in the region. Urban water governance is pertinent in decision-making and policies designed based on the determinants of sustainability (society, economic and environmental). Due to the complexity of the decision-making system, fragmentation, poor coordination and lack of holistic planning, developing adaptive capacity in the developing region is underexplored. In this background, this chapter reviews the concept of urban water governance and its pathways to achieve adaptive water Governance in India. The main question here is which urban water governance pathway suits the Indian context and what are the barriers to implementing adaptive water governance in India. The analysis showed that water institutions' non-responsiveness, coordination/interaction issues, lack of collaboration, limited information access and communication between various levels of formal institutions and absence of capacity building and challenges to ensure fairness in distribution are the identified barriers. Furthermore, this chapter argues that the implementation of adaptive water governance through hybrid governance configuration is in the experimental phase in India and shows promising results. Evaluating the success of polycentric arrangement is too early now. Addressing the constraint herein, improving the dimension of the adaptive system mentioned in the section will enhance the strength of the urban water governance system to handle uncertainty in the future. The chapter contributes to the current discourse of the water governance pathways to achieve water security in developing countries in support of the water goal (SDG 6) of the United Nation's sustainable development goals.

The book began with multifaceted concept of urban water security in the context of global environmental changes. It was followed by discussion on emerging challenges such as climate change, urbanization, population and their implications on different dimensions of urban water security. Considering the inadequacy of current water management systems, there is a need of transition towards sustainable and innovative solutions, mainly in developing countries. The sustainable solutions presented in the various chapters are summarized here. It is shown in this chapter, how the arguments of this book bring different contours of urban water security. The chapter also argues that different solutions represented here deserve an equal weight when considering their application in real-world situations. Accordingly, a synthesis of key lessons is provided for better integration of the solutions for long-term urban water security in urban context.