This thesis aims to understand if decision-making processes and institutional factors in Dutch municipalities hinder or enable the implementation of climate adaptation measures in urban drainage systems, and consequently climate adaptation efforts in the Netherlands. Interview findings showed that decision-making processes are evolving to incorporate climate adaptation efforts where possible. Implementation of climate adaptation measures was identified to occur when there was an opportunity to incorporate them into other necessary infrastructure projects, such as large-scale neighbourhood redevelopments, however taking advantage of these opportunities depended not only on their existence, but also on current institutional factors. Frequently identified hindering and enabling factors included the availability of financial resources, the current regulatory framework, fragmented roles and responsibilities within municipalities and the availability of sufficient and appropriately skilled personnel. Factors such as cultural/cognitive resistance and political incentive to action were also identified as hindering and enabling climate adaptation efforts. Interview findings also showed that in addition to the institutional factors, the actors involved in the decision-making process and the resources available to these actors played an important role in the decision-making processes. Four key actors were identified from the data: technical designers/ decision-makers, the local community, the municipal council and housing developers. The support or resistance of these actors strongly impacted the duration of the decision-making process and success implementing climate adaptive measures. Though the decision-making processes are evolving, the use of opportunity-based initiation tactics and ineffective bargaining tactics resulted in processes were often stalled or blocked prior to decision implementation. Improvements can be made to the decision-making tactics used by practitioners, however, the processes by themselves were not found to act as distinct hinderances. The institutional context within which these decisions are made has significant influence on the outcomes of the process and the institutional factors identified indicate that the current context is more hindering than enabling. Strategies to address some of these hindering factors can therefore also facilitate the decision-making processes and lead to an increase in implementation of climate adaptation in urban drainage systems.