Today's expansion and densification of cities, where more space is being impermeably surfaced by grey infrastructure, means an increased risk of flooding. An urban space with reduced green areas is less resilient to increased temperatures. In dealing with this, research has pointed to the complementarity of Nature-based Solutions (NBS) in contributing to more resilient and cost-efficient flood management. NBS do not only serve to reduce risk for flooding and drought, they also provide additional sustainability values, such as strengthening ecosystem services through increased biodiversity and recreation opportunities. In many circumstances, combining this NBS with traditional grey infrastructure can provide next generation solutions that enhance system performance and better protect communities. The study has focussed on subjects argued as central to provide a business value for upstream landowners to perform NBS measures. Results of the Workshop on Nature Based Solutions for flood and drought prevention organized in May 2019 in Gothenburg substantially contributed this study. The main objective of the study is to propose developments that can lead to business models and financial instruments that support the adoption of upstream water retention through Nature-based Solutions based primarily on research from the Västra Götaland region of Sweden.