This chapter discusses the tensions of legitimacy in flood risk management resulting from the claim for more flood resilience. It also discusses the concept of legitimacy and explains the theoretical framework using an elaborated literature review. The chapter describes the erosion of legitimacy components in the resistance approach. Reference is made to empirical research conducted in the Netherlands in 2014. Eight water management experts of the water boards, Deltares and municipalities have been interviewed about issues of flood risk management and its legitimacy. Findings have been validated in reference to their professional experience with projects with issues of legitimacy. The interviews were thereby used to link theory and practice. The chapter proposes the claim for an extra form of legitimacy to extend the legitimacy of flood risk management. Dutch resistance-based flood protection rests on strong institutions and on their promise to defend citizens and their land from floods.