This book has been written specifically for practitioners involved in the operation, maintenance and management of piped water distribution systems in urban areas of developing countries. These practitioners include engineers, planners, managers, and water professionals involved in the monitoring, control and rehabilitation of water distribution networks. The book explains in detail how to evaluate the risk of deterioration of the water distribution network of a water supply system. It begins with the conceptualization of risk evaluation and its three different components (hazard, vulnerability and risk). The book further elaborates on each of these three components, explains the methodologies used to estimate the components, and presents the background to the mathematical models. Finally, the book explains how these components are integrated to form a GIS-based decision support system for risk evaluation. The book is designed to help practitioners understand the concept of risk evaluation and supports the manual of the IRA-WDS software, a GIS-based decision support system for risk evaluation.

The objective of this study is to assist public authorities to identify and address the future challenges of urban water supply, sanitation, and flood management in cities. In order to do that, this report uses the conceptual framework of Integrated Urban Water Management (IUWM) as a holistic set of planning and management tools incorporating all components of the urban water cycle to help develop efficient and flexible urban water systems in the future. The future of water in African cities: why waste water? argues that a new approach to urban water management is needed in Africa. Due to their rapid urbanization, cities in Sub-Saharan Africa will face increasing challenges in order to provide water supply to the growing population. Future water supply for cities will also depend on the potential to sustain water resources of good quality in the river basin and to manage competing uses within the watershed. The complexity of these challenges coupled with future uncertainty due to climate change will require a more sustainable, integrated and adaptive water management approach. Reviewing a series of case studies in Uganda, Kenya and Cameroon, and having conducted a diagnostic of 31 cities in Sub-Saharan Africa, this report suggests that the challenges faced by cities in Africa cannot be solved by the traditional approach of one source, one system, and one discharge. The 4 cases studies of this report illustrate the combination of existing technology and surface water with new sources (e.g. groundwater and greywater recycling) within the river basin that will increase water security for cities. In some cases, planning decentralized and modular solutions will bring more flexibility and adaptation to expanding cities. The future of water in African cities: why waste water? is aimed at urban planners, water managers, policy makers, development agencies and stakeholders interested in innovative solutions to urban water management challenges. IUWM will help policymakers in African cities consider a wider range of solutions, understand water s interaction with other sectors, and secure resilience under a range of future conditions."