The impact of climate change isincreasingly important for the design, construction, andmaintenance of water sector infrastructure. Average globaltemperatures are on the rise, causing cycles of extremeweather: droughts and flooding are becoming common; seawaterlevels are rising; and many locations are considerablydrier, impacting water sources such as lakes and rivers.Groundwater supplies are under stress due to decreasingprecipitation rates and increasing extraction rates. Urbanwater systems must meet the demands of expanding industryneeds and rapid population growth. Pollution adds to thegrowing threats to water resources, increasing treatmentrequirements for providing safe water to city residents.With two-thirds of the world's megacities located inregions that are vulnerable to the impacts of climatechange, urban water utilities are facing an increasing needto improve the management of water resources and associatedinfrastructure. Diversifying sources of water supply willbecome increasingly important whether through theconstruction of new storage facilities, the appropriate andsustainable extraction of groundwater, water trading orconservation, or the use of recycled or desalinated water.This water note, based on the input of 20 large utilitiesaround the world presents the perceptions, experiences, andapproaches to addressing climate related challenges of urbanareas in developing, middle income, and developed countries.