Urbanization of the Earth's population will have increased the Earth's urban population from less than one billion in 1950 to five billion by 2030. Managing water for this burgeoning urban population is one of the critical needs for humanity. This book uses a holistic, interdisciplinary approach to examine the urban water environment. Water has multiple roles: municipal water supply, aquatic habitat, landscape aesthetics and recreation. Increasingly, urban water is reused, serving multiple purposes. Humans alter the urban hydrologic cycle and the chemical and physical integrity of urban water systems and resources. Some of those changes are beneficial, and others harmful. Understanding those changes and impacts requires expertise and perspective from a wide range of disciplines. Chapter authors represent this diversity of expertise, with expertise in surface and groundwater hydrology, civil and environmental engineering, environmental policy, urban planning, law, geomorphology, and recreation management.