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.

Cities worldwide are faced with the challenge of adapting to the effects of climate change as well as acting against climate change, in order to keep the urban area liveable in the future. To facilitate climate adaptation and mitigation on a national level, the Netherlands drew up guidelines to induce the energy transition, as part of the ‘Climate Agreement’, and to guide urban areas to adapt to the effects of climate change, as part of the ‘Deltaplan of Spatial Adaptation’. Both the energy transition and climate adaptation require context-specific solutions and place large spatial claims on cities. To create understanding on what the effects of the energy transition are on the possibilities for climate adaptation, in this research an explorative case-study is conducted, based on multiple and diverse cases in Rotterdam. Rotterdam’s main climate adaptation goal with regard to water resilience is to make the water-storing capacity of public space sufficient to prevent damage in the event of heavy rainfall (70 mm of rainfall within one hour). In order to find an answer to the question of what the energy transition entails for this goal, five pilot areas in Rotterdam that switch to a gas-free network in the coming years were taken as study sites and were thoroughly analysed to select cases. Cases have been selected based on their criticality: locations that are prone to urban flooding, in addition to the implementation of energy measures. For each of the five selected cases, cross-sectional designs were created for three situations: the existing situation, the situation with energy measures (and sewer replacement, if applicable) and the situation with climate adaptation measures. These designs formed the basis to empirically gather information on the different types of systems integration (project-based, geographical, physical and informational) between the energy transition and climate adaptation. By analysing five different cases in Rotterdam, concrete examples have been collected of how the implementation and planning of energy measures affect climate adaptation and of what the energy transition ultimately entails for Rotterdam’s climate adaptation goals. In addition, policy dilemmas have been formulated for the municipality with regard to the rainwater storage to be achieved and the extra costs associated with measures. This research indicates the difficulties associated with implementing both the energy transition and climate adaptation in densely built areas and tries to provide suggestions for exploiting potential opportunities that the energy transition can create for climate adaptation.

Climate change adaptation is needed in response to the extreme weather events such as heat waves and rainfall-induced flooding in the Netherlands. There is a mandate from the national government to become climate- and water-proof by 2050, and the onus is on local governments to fulfill these goals. Local governments, in turn, need to activate stakeholders in their networks to become more climate adaptive. This research focuses on one group in particular, businesses located on business parks. Via the Q-methodology, fourteen businesses are interviewed and their perspectives with respect to the need and urgency for, as well as, the costs and benefits of climate adaptation are documented, analyzed, and interpreted, resulting in a typology of business perspectives on climate change adaptation. Specific recommendations for government are presented based on this more nuanced understanding of the motivations and barriers businesses face. Specifically, subsidy is largely rejected, the role of regulation remains important for some, and for all, the real risks and practical solutions are needed, which is viewed as the role of government to communicate.

In recent decades, sustainable urban drainage systems (SUDS) are more often seen as an addition to, or a replacement of, traditional piped urban drainage (UD) systems. Unfortunately, failures in SUDS still occur regularly, resulting in malfunctioning systems, water nuisance and high costs. To learn from past experiences and to ensure that SUDS in the future can function as a credible alternative to piped UD systems, these failures should be identified, and the underlying reasons more thoroughly understood. Therefore, the research objective of this study was to create a better understanding of technical failures in SUDS and identify their root causes. In creating this understanding, cases of technical failures in SUDS were collected and interviews were conducted to reveal information about their root causes. The observations showed that the implementation of SUDS in the urban environment present new interfaces between systems, disciplines and responsibilities. These interfaces between SUDS and subsystems were shown to be prominent failure locations. The interviews revealed that designers, constructors and operators often lack knowledge about these interactions and their impact on the performance of SUDS. Combining the results of technical failures and the underlying root causes showed that throughout the whole development process of SUDS (i.e. design phase, construction phase and user/maintenance phase) technical failures arise. In minimizing these technical failures, every project phase should focus on certain root causes behind technical failures. The classification of the 13 identified root causes revealed that root causes stem from uncertainties in technical, social and institutional systems and are located both within (internal) and between systems (interface). Previous research focused mainly on barriers in the socio-institutional system, this research however showed that we should just as much focus on the technical system. Moreover, previous research primary focused on the performance of SUDS in their context, this study revealed that interfaces between SUDS and other urban subsystems are critical and deserve extra attention in future projects. Further research is required to systematically keep record of the problems and failures occurring in SUDS.