Losses In Water Distribution Networks

This is a best practice manual for addressing water losses in water distribution networks worldwide. Systems and methodologies are presented for improving water loss and leakage management in a range of networks, from systems with a well-developed infrastructure to those in developing countries where the network may need to be upgraded. The key feature of the manual is a diagnostic approach to develop a water loss strategy - using the appropriate tools to find the right solutions - which can be applied to any network. The methods of assessing the scale and volume of water loss are outlined, together with the procedures for setting up leakage monitoring and detection systems. As well as real losses (leakage) procedures for addressing apparent losses, by introducing regulatory and customer metering policies are explained. Suggestions are made for demand management and water conservation programmes, to complement the water loss strategy. Recommendations are made for training workshops and operation and maintenance programmes to ensure skills transfer and sustainability. The manual is illustrated throughout with case studies. Losses in Water Distribution Networks will appeal to a wide range of practitioners responsible for designing and managing a water loss strategy. These include consultants, operations managers, engineers, technicians and operational staff. It will also be a valuable reference for senior managers and decision makers, who may require an overview of the principles and procedures for controlling losses. The book will also be suitable as a source document for courses in Water Engineering, Resource Management and Environmental Management.

Water utilities worldwide lose 128 billion cubic meters annually, causing annual monetary losses estimated at USD 40 billion. Most of these losses occur in developing countries (74%). This calls for rethinking the challenges facing water utilities in developing countries, foremost of which is the assessment of water losses in intermittent supply networks. Water loss assessment methods were originally developed in continuous supply systems, and their application in intermittently operated networks (in developing countries) is hindered by the widespread use of household water tanks and unauthorised consumption. This study provides an extensive review of existing methods and (software) tools for water loss assessment. In addition, several new methods were developed, which offer improved water loss assessment in intermittent supply. As the volume of water loss varies monthly and annually according to the amount of supplied water, this study proposes procedures to normalise the volume of water loss in order to enable water utilities to monitor and benchmark their performance on water loss management. The study also developed a novel method of estimating apparent losses using routine data of WWTP inflows, enabling future real-time monitoring of losses in networks. Different methods have also been suggested to estimate the unauthorised consumption in networks. This study found that minimum night flow analysis can still be applied in intermittent supply if an area of the network is supplied for several days. Furthermore, this study concluded that water meter performance is enhanced in intermittent supply conditions. However, continuous supply in the presence of float-valves significantly reduces the accuracy of water meters. Finally, this study provides guidance and highlights several knowledge gaps in order to improve the accuracy of water loss assessment in intermittent supply. Accurate assessment of water loss is a prerequisite for reliable leakage modelling and minimisation as well as planning for, and monitoring of water loss management in distribution networks.

Knowing how to manage the losses from water supply networks and how to get to the next level in bettering your system is a major problem and one that is most common in the majority of water companies worldwide. Sometimes water companies set their sights too high and cannot deliver due to non-realistic targets setting. Of course this is considered or seen as a failure within the company or country when it is really just exceeding expectations of what can be delivered. The aim of System Losses from Water Supply Networks is to assist water companies to identify where they are on the ‘water loss ladder’ and what is required to move to the next level. The book will provide an understanding of what the water companies need to achieve and where they should be aiming for in their efforts to reduce water losses. The book provides useful and practical information on non-revenue water (NRW) issues and solutions enriched with relevant case studies.

Protecting and maintaining water distributions systems is crucial to ensuring high quality drinking water. Distribution systems-consisting of pipes, pumps, valves, storage tanks, reservoirs, meters, fittings, and other hydraulic appurtenances-carry drinking water from a centralized treatment plant or well supplies to consumers' taps. Spanning almost 1 million miles in the United States, distribution systems represent the vast majority of physical infrastructure for water supplies, and thus constitute the primary management challenge from both an operational and public health standpoint. Recent data on waterborne disease outbreaks suggest that distribution systems remain a source of contamination that has yet to be fully addressed. This report evaluates approaches for risk characterization and recent data, and it identifies a variety of strategies that could be considered to reduce the risks posed by water-quality deteriorating events in distribution systems. Particular attention is given to backflow events via cross connections, the potential for contamination of the distribution system during construction and repair activities, maintenance of storage facilities, and the role of premise plumbing in public health risk. The report also identifies advances in detection, monitoring and modeling, analytical methods, and research and development opportunities that will enable the water supply industry to further reduce risks associated with drinking water distribution systems.

The book provides a scientific approach into appraising Intermittent Water Supply (IWS) on a global scale through the analysis of available information and data based on a structured methodology for estimating the population affected by IWS worldwide both by country and by geographical regions. The root causes and the implications of IWS are dealt with in a concise manner providing a detailed account of the reasons for resistance to change towards 24x7 supply. A major contribution of the book is in providing an understanding of water losses in the context of IWS as well as the related difficulties in leakage detection and metering under such conditions. A methodology is presented for transitioning from IWS to continuous supply covering technical, social and communication issues which are considered of paramount importance for a successful transition. Relevant case studies from across the globe are included in the book to provide evidence based information and data relating to the many and diverse challenges faced daily by water utilities operating their networks under IWS.

Remote sensing has been used for water management purposes over the years. This book describes the combination of satellite imagery, in-situ spectroradiometric data and radar techniques for the identification of water leakages in the water supply network in both rural and urban areas in Cyprus. This book presents a holistic approach combining new technologies for a complete system of water distribution network leakage detection management, by combining Global Navigation Satellite Systems (GNSS), Geographical Information Systems (GIS), Satellite Remote Sensing techniques as well Geophysical surveys such as ground penetrating radar (GPR), Unmanned Aerial Vehicles (UAV) and spectro-radiometric measurements, which can be used to effectively identify and monitor water leakages.