This book is a successor to and replacement for the highly respected manual and handbook on the benefits of flood and coastal risk management, produced by the Flood Hazard Research Centre at Middlesex University, UK, with support from Defra and the Environment Agency. It builds upon a previous book known as the "multi-coloured manual" (2005), which itself was a synthesis of the blue (1977), red (1987) and yellow manuals (1992). As such it expands and updates this work, to provide a manual of assessment techniques of flood risk management benefits, indirect benefits, and coastal erosion risk management benefits. It has three key aims. First it provides methods and data which can be used for the practical assessment of schemes and policies. Secondly it describes new research to update the data and improve techniques. Thirdly it explains the limitations and complications of Benefit-Cost Analysis, to guide decision-making on investment in river and coastal risk management schemes.