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 24×7 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.