Water Supply And Demand

This book is the result of a joint research effort led by the U.S. National Academy of Sciences and involving the Royal Scientific Society of Jordan, the Israel Academy of Sciences and Humanities, and the Palestine Health Council. It discusses opportunities for enhancement of water supplies and avoidance of overexploitation of water resources in the Middle East. Based on the concept that ecosystem goods and services are essential to maintaining water quality and quantity, the book emphasizes conservation, improved use of current technologies, and water management approaches that are compatible with environmental quality.

Presents two alternative scenarios of water demand and supply for 118 countries over the 1990 to 2025 period and develops indicators of water scarcity for each country and for the world as a whole. This study is the first step in IWMI’s long-term research goal: to determine the extent and depth of water scarcity, its consequences for individual countries and what can be done about it.

A common characteristic of water demand in urban areas worldwide is its inexorable rise over many years; continued growth is projected over coming decades. The chief influencing factors are population growth and migration, together with changes in lifestyle, demographic structure and the possible effects of climate change (the detailed implications of climate change are not yet clear, and anyway will depend on global location, but must at least increase the uncertainty in security of supply). This is compounded by rapid development, creeping urbanization and, in some places, rising standards of living. Meeting this increasing demand from existing resources is self-evidently an uphill struggle, particularly in water stressed/scarce regions in the developed and developing world alike. There are typically two potential responses: either "supply-side" (meeting demand with new resources) or "demand-side" (managing consumptive demand itself to postpone or avoid the need to develop new resources). There is considerable pressure from the general public, regulatory agencies, and some governments to minimise the impacts of new supply projects (e.g. building new reservoirs or inter-regional transfer schemes), implying the emphasis should be shifted towards managing water demand by best utilising the water that is already available. Water Demand Management has been prepared by the academic, government and industry network WATERSAVE. The concept of the book is to assemble a comprehensive picture of demand management topics ranging from technical to social and legal aspects, through expert critical literature reviews. The depth and breadth of coverage is a unique contribution to the field and the book will be an invaluable information source for practitioners and researchers, including water utility engineers/planners, environmental regulators, equipment and service providers, and postgraduates. Contents Water consumption trends and demand forecasting techniques The technology, design and utility of rainwater catchment systems Understanding greywater treatment Water conservation products Water conservation and sewerage systems An introduction to life cycle and rebound effects in water systems Developing a strategy for managing losses in water distribution networks Demand management in developing countries Drivers and barriers for water conservation and reuse in the UK The economics of water demand management Legislation and regulation mandating and influencing the efficient use of water in England and Wales Consumer reactions to water conservation policy instruments Decision support tools for water demand management

This detailed study of the use of water at different price levels by residential consumers in the Toronto-centred region from Hamilton to Oshawa challenges the basis of our present urban water supply policy. Adoption of the recommendations presented would mean higher prices to householders, but a considerable saving of hundreds of millions of tax dollars over the next three decades. The present policy uses a 'requirement approach' in which future water needs are calculated by extrapolation of past trends and an assumption that demand is inelastic. This leads to excessive levels of water use and over-investment in water supply, sewage collection, and treatment systems. The resultant misallocation of resources can be corrected by adoption of a demand/management approach in which investment policy is guided by consumer demand and alternative pricing arrangements are used as a management tool. Dr. Grima examines several alternative choices for management, such as metering, increasing marginal prices, sewerage charges, seasonal charges, and an increasing price block schedule, and describes the results of each. Water managers in Canada are strongly challenged to begin a fundamental rethinking of their basic policies. (Department of Geography Research Publication 7)

In the last twenty years the problem of urban public water supples has become increasingly serious. Disparities between the effective supply of, and demand for, water has grown rapidly and now constitute a danger to public health. This study deals with the place of urban public water supplies in economic development and with the demand for such elements of the social infrastructure during the process of economic and social growth. Based on an examination of the existing water-use systems in two urban areas in India, this study provides valuable information in a field that is of growing concern to all the developing countries of the world.

Managing Water Demand provides a comprehensive account of the tools used to manage water demand in the MENA region. The vast arid and semi-arid regions of the Middle East and North Africa region (MENA) constitute 85% of the region's land area and are home to approximately 60% of the region's population. Limited water resources pose severe constraints on people's economic and social progress, testing their resilience and threatening their livelihoods. Rainfall is not only scarce and unpredictable, but the region is also subject to frequent and severe droughts. Available surface water is declining and the over-pumping of groundwater beyond natural recharge rates is occurring, lowering the water table and causing an increase in groundwater salinity and ecological degradation. Water Demand Management (WDM) is about governance and tools that motivate people and their activities to regulate the amount and manner in which they access, use and dispose of water to alleviate pressure on freshwater supplies. It is also about protecting water quality. The development and promotion of such WDM practices, primarily for governments in the Middle East and North Africa (MENA) region, have constituted the core objectives supported by Canada's International Development Research Centre (IDRC) and its partners through the Water Demand Management Forums. Managing Water Demand provides a comprehensive account of the tools used to manage water demand in the MENA region. A critical review is presented of the efficacy of WDM techniques in the areas of wastewater reuse, water valuation, public-private partnerships and decentralization, and participatory irrigation management. This book will provide some of the necessary knowledge required to further promote WDM in the MENA region, while providing insight into the work required for much needed change to improve water governance.