With the infrastructure to manage stormwater threats in cities becoming increasingly expensive to build or repair, planners and landscapers need to look at alternative approaches. Ground-level mitigation measures such as raingardens, bioswales and rain water harvesting are becoming increasingly relevant, but very little work has been done to assess the potential benefits of green roofs as part of a holistic urban water management system for larger urban areas. This book demonstrates the tools to measure and evaluate the effectiveness of green roofs for cities in different climates to manage urban runoff. Planned and implemented properly, a green roof strategy can reduce pressure on ageing infrastructure, protect streams and lakes, and ultimately save the huge costs associated with stormwater control.