Adapting urban water systems to climate change : a handbook for decision makers at the local level

ICLEI, UNESCO-IHE and IWA have authored, as part of the ‘SWITCH – Managing Water for the City of the Future’ project, a handbook on adapting urban water systems to climate change. The handbook aims to fill a gap in the adaptation field: while a lot of information is available about various adaptation topics, there is a lack of guidance for decision makers at the local level working on urban water who wish to proactively prepare for and adapt to climate change. The handbook first examines some of the key areas of vulnerability to climate change within urban water systems. Urban water systems  can be affected by most of the predicted climatic changes; for example, droughts can affect water supply directly and indirectly (when vegetation regrowth after wildfires reduces catchment yields), higher temperatures can lead to the deterioration of wastewater pipes and increased heavy rainfall can cause combined sewer overflows. The handbook also proposes flexible and future-oriented urban water planning as a means to address climate change and implement adaptation actions. This can be achieved through strategic planning, which is a continuous, regularly evaluated process with ongoing choices designed to cope with changing circumstances. Adaptation-specific steps such as a vulnerability assessment can easily be fitted into such a process. Finally, the handbook presents case studies of cities throughout the world that have already planned for adaptation or implemented specific actions aiming at increasing their resilience to climate change. [authors abstract]