This handbook on adaptation of urban water systems to climate change will provide local governments and utilities with up-to-date information as well as access to resources and good practice examples. This will enable them to increase their awareness of how the potential impacts of climate change will affect their urban water systems and to build their capacity to develop a long-term strategy for adaptation in the water sector. The handbook aims to distil the most relevant aspects of adapting to climate change for urban water management. For example, the handbook details the main anticipated impacts of projected climatic variations on urban water systems and services, but does not go into scientific explanations about the causes of climate change. This handbook is aimed at local governments and utilities in cities of all sizes in both developed and developing countries. Certainly, much of its content has been drawn from the experiences of larger developed country cities, due to their greater familiarity with adaptation planning and implementation. However, the methods and concepts laid out in this handbook are applicable at all scales and levels of economic development, since adaptation is not merely a matter of available finances but also of knowledge and sound planning. A lot can also be achieved through the accumulation of individual adaptive actions. The handbook will be most useful for mid-level managers and strategic planners within utilities or relevant local government departments who are responsible for making decisions in the area of urban water management. Indeed, such managers and planners possess the necessary background both to understand the wider implications of climate change and to grasp the practical realities of adapting to it, and are thus able to initiate real change but also to wield influence at the political level.