Extreme sea level events are more likely to occur more frequently in the future due to climate change. Therefore, new approaches to flood risk management must be explored. Instead of following a solely defence-dominated engineering approach, improving resilience has become increasingly popular and more desirable. Nature-based solutions (NBS) are actions inspired by, supported by or copied from nature that simultaneously help societies address environmental, social and economic challenges. Therefore, they have the potential to contribute to a more resilient Flood Risk Governance (FRG). However, implementing new perspectives will inevitably widen the scope and increase the number of stakeholders involved in the decision-making process. The idea of more collaborative and participatory governance has gained increased interest among researchers. Nevertheless, influential stakeholders often prefer solutions that cost less and hold fewer management complications and risks, even if other, more multi-functional solutions might be more beneficial for the other stakeholders and society. To further contribute to the knowledge of FRG and the implementation of NBS, this thesis aims to explore how the current FRG can be enhanced for the implementation of nature-based flood defence systems.

The chosen approach is a qualitative study. In addition to reviewing related literature, a first round of interviews explores the current FRG. Furthermore, a multiple-case study was selected as a research method. Data was gathered through interviews and document review in a thematic analysis. Both barriers and enablers for the design and implementation of NBS were identified. Ultimately, the research discovered that barriers and enablers are deeply interconnected, which was depicted in a framework. Moreover, the framework was categorised into three levels of governance. From there, recommendations are given to relevant stakeholders.

The Netherlands can reflect on a long history of living with water, leading to a well-defined FRG with clearly divided responsibilities. Nevertheless, this historical and cultural background also made the system somewhat rigid, making the integration of novel approaches, such as NBS, rather difficult. Several barriers and enablers for wider NBS implementation have been identified within the case studies. Moreover, potential solutions were extracted.

Based on the framework, the study provides a set of policy recommendations targeted at Rijkswaterstaat and other stakeholders of the Dutch FRG. These recommendations focus on enhancing governance flexibility, fostering interdependencies, and creating incentives to overcome risk aversion and promote nature-based approaches. Additionally, the study suggests revising existing legislation to accommodate adaptive management practices better and integrating long-term monitoring and evaluation to support continuous learning and improvement.

The study concludes that better integration of NBS in FRG requires addressing distinct areas of responsibilities, encouraging adaptive and flexible governance arrangements, and promoting collaborative approaches to policymaking. By enhancing stakeholder engagement and providing adequate financial and regulatory support, the Netherlands can improve the resilience of its flood protection system while harnessing the multiple benefits offered by NBS.

Many Dutch infrastructure assets were constructed in the first half of the 20th century and by considering an average design life time of roughly 100 years, a lot of these structures will reach the end of their designed life in the upcoming decades. This results in a large replacement and renovation challenge in the nearby future. Assessing the end of life of individual critical hydraulic structures (case studies) and prolonging their lifetime by suggesting adaptive measures is of importance to better define and solve this challenge. In this research, the Haringvliet sluices are used as a case study.

The focus of this research is to apply two existing methods, the framework of Vader et al. (2023) and the Adaptation Pathway Approach of Haasnoot (2013), to the Haringvliet sluices, to make an estimate of the remaining life time and to propose suitable measures to elongate it. Next to this, this research aims to connect both methods mentioned above to create a new integral method. This full method aims to qualitatively and quantitatively analyse hydraulic structures and map out possible paths to elongate its remaining life time. The results of this thesis provide valuable insights in assessing the remaining lifetime of different hydraulic structures in the future. The Haringvliet sluices are an interesting candidate for this research due to the many functions it has to fulfil and the complexity of its interactions within the water system.

The first part of the analysis on the Haringvliet sluices describes the functional analysis as well as the technical decomposition performed on the Haringvliet sluices. The goal of the functional analysis is to define requirements for each of the functions. The goal of the structural decomposition is to identify the most important deterioration mechanisms of the structural elements, which in turn are important in estimating the remaining technical life. The next step in the analysis aims to either qualitatively or quantitatively describe the external drivers which influence the functional performance and technical state of the Haringvliet sluices. The external drivers to consider for the Haringvliet sluices, or hydraulic structures in general, can be subdivided into physical external drivers and economic, political and societal drivers. From this analysis, the drivers which are expected to have the most severe influence on the Haringvliet sluices are defined. For the Tipping Point analysis in the next part of the analysis, existing models are evaluated and used to quantify Tipping Points due to the expected most dominant driver and function combination. A Tipping Point is reached if the system fails to meets its technical or functional requirements due to changes caused by the external drivers. The dominant combination investigated in the analysis is the effect of sea level rise on the flood protection function. The Tipping Point analysis shows that there is a large dependence of the Tipping Points on the evaluation criteria. The analysis gives insight in how other evaluation criteria, like accepting more overflow discharge over a dike section, could impact the Tipping Point. Even though Tipping Points are sensitive to decisions on evaluation criteria and chosen climate scenarios, it does provide valuable insights in the response of the system to sea level rise when investigating different decision criteria. In the last part of the analysis an Adaptation Pathway for the remaining lifetime of the Haringvliet sluices is presented by proposing life elongating measures. Life elongating measures for the Haringvliet sluices can be split into two different categories: Strategies for the bigger water system, i.e. future visions for the Dutch Delta, which could have either a positive or negative effect on the remaining life and life elongating measures focussed on the object or direct system. It is chosen to only investigate mitigation measures focused on the Haringvliet sluices and its direct system.

Each sub-analysis in the total research design has its individual results and therefore its individual assumptions, limitations and critical remarks. The assumptions and limitations of previous steps could have a significant impact on other steps in the analysis. One of the biggest uncertainties in the results of the remaining life time of the Haringvliet sluices is that there is a possibility that other critical combinations found from the driver analysis would reach a potential Tipping Point sooner than the one investigated in this research. Also, the impact of the proposed mitigation actions for the Adaptive Pathways needs to be revaluated on their impact on other function or technical requirements, i.e. an extra feedback loop is needed. The full analysis must be run through several times to create a more complete overview of the most critical ways a structure could reach its end of life and to indicate which measures could be best applied at what time.

By applying the methodology proposed by this research to other case studies and by conducting more research on assessing the remaining life time of critical hydraulic structures, key insights can be found in how to manage our critical hydraulic infrastructure in an adaptive way to elongate their life time.

Being both a low-lying delta and having one of the most significant mortgage-to-debt-to-GDP ratios in the world, the Dutch economy is vulnerable to damages to real estate due to floods as this could lead to large-scale householder default and ultimately destabilize their economy. Notwithstanding, a generic and widely adopted tool to assess flood risks and their subsequent effect on real estate values in practice is yet to be constructed. This research aimed to understand the potential impact of flood vulnerability on real estate values, the economic models guiding the assessment, and the subsequent role of stakeholders in maintaining the stability of the values.

A combination of quantitative and qualitative methods was employed throughout this study to answer the primary research question. First, state-of-the-art models for examining the effect of floods were explained through a literature review. Second, a framework was constructed to define flood vulnerability, including socio-economic status, disaster-bearing capabilities, and flood exposure. This enabled the quantification of flood vulnerability levels of neighborhoods in the case study. Third, qualitative methods in the form of a literature review and exploratory semi-structured interviews with stakeholders were utilized to understand their barriers, drivers, and enablers and the ensuing opportunities to contribute to maintaining the stability of real estate values.

The results indicated that the definition and usage of the parameters are vital to assess the effects of flood risks on residential real estate values. In addition, the results showed significant effects on flood vulnerability when including a subset of indicators besides flood exposure. When constructing a more accessible tool for all stakeholders, employing a more integral definition of flood vulnerability may thus be more socially just. Stakeholders may contribute to the stability of real estate values by actively adapting and incentivizing each other to similar behavior.

In addition, organized irresponsibility (i.e., stakeholders contributing to an issue without wanting to take responsibility for the caused risks) and pillarization appear to be embedded within the system in the Netherlands. Through cooperation, division of responsibilities, and taking ownership, devaluation risks may be diminished and the phenomenon of organized irresponsibility reduced. Moreover, by prolonged engagement of initiating stakeholders, a shift from short-term profit to long-term real estate values may be stimulated, potentially contributing to the prevention of enlarged social injustice due to flood risks. Within the shift towards organized responsibility, this research hints towards a vital role for both the government and insurers.

The Meuse is a river in West-Europe which rises at the Langres Plateau and flows from France through Belgium and the Netherlands. The river has always been an important shipping route, even though its navigability has been problematic in the Netherlands. To solve this problem seven weirs were constructed in the Dutch part of the Meuse. They are located at Borgharen, Linne, Roermond, Belfeld, Sambeek, Grave and Lith. Weirs are hydraulic structures and mainly control the upstream water level to allow for sufficient depth for shipping. Structures such as weirs generally have a technical life span of 100 years, and because the Meuse weirs were built 100 years ago they are up for replacement. Rijkswaterstaat wishes to have uniformity in the designs of the next Meuse weirs. This decreases the amount of unique components which in turn leads to the reduction of repair and maintenance costs.

The main objective of this thesis is to determine the most cost-efficient maintenance strategy for the next generation Meuse weirs. Part of the objective of this study is also to determine the influence of ship collisions on the availability and costs of weirs. In this thesis a case study is used to set up the analysis. The case study consists of two weir alternatives that were proposed as the replacement for the weir in Grave.

Based on the results for both the availability and costs of both maintenance strategies in this report it seems that the preventive maintenance strategy performs better than the corrective maintenance strategy for both weir alternatives. The availability under preventive maintenance is higher and the total costs (maintenance costs and repair costs) are lower under preventive maintenance. The availability of the weirs are mostly influenced by the failure mechanism of ship collision and the weir component “hydraulic aggregates”. The largest contributor to the maintenance costs are the hydraulic cylinders and for the repair costs the most significant contributor are the hydraulic aggregates. Ship collisions seem to influence the availability greatly, but has limited influence on the repair costs of the weirs.

In the upcoming years in the Netherlands, the Dutch government will be focusing on renovating infrastructure assets. Moreover, a shift from organizing each project individually to a more program-oriented approach has been observed in renovating infrastructure, whereby synergy a prominent feature is. In addition, it is becoming increasingly apparent that non-functional goals that focus on adding value (secondary goals) are outlined for construction programs besides functional goals. However, minor studies have been conducted to examine how achieving diverse program goals can be controlled and how a synergy can be optimally utilized in infrastructure renovation programs (IRP). The method used to improve utilizing this full potential is twofold, it consists of a literature study followed by empirical research, which consists of conducting three case studies and their synthesis. The proposed solution to gain control over both the primary and secondary goals of IRP is to shift the focus of control on performance this in turn would take control of the process. Regarding obtaining interpretable information, careful and constant attention to the connection between which content is essential and how this is acquired is critical. Considering the program organization, firstly, stimulating a collaborative working environment when executing tasks and creating awareness of the beneficial collective program management approach is essential. Secondly, implementing a change management procedure has been suggested. Lastly, the program management team should prioritize what needs to be coordinated on program level and what should be organized for all projects individually. The empirical research performed has generated in new synergy benefits that have not been described in scientific literature previously. Those new synergies found are the opportunity of empowering political urgency, removing obstacles that are in the way of performing research, decision-making based upon broad knowledge and a comprehensive overview of risks. To utilize all forms of synergy, the equilibrium between making the program manageable and utilizing synergy should be found by a combination of working in departments on tasks and practicing an integral way of working. To utilize the advantages of conducting research collectively, the focus should be directed upon the developments of the application-oriented innovation by associating the innovation directly to the program goals and involve knowledge institutions in the process. In order to utilize the program’s potential, it is recommended to program managers to notice and understand the forms of synergy accessible. Also, it is recommended for program managers to be aware of the tension between project and program management. Besides, a recommendation to program managers is to focus on the attitude of the program team towards the collective program approach. Furthermore, it is recommended that program managers reflect on their program to find out what barriers occur in their problem. Hence, the program manager can use this research to concretize actions on how to achieve improvements of their program. In addition, enabling the power of the iterative process is recommended. Lastly, structuring the improvements in the light of the program management cycle gives footing.

The Hollandsche IJssel storm surge barrier is expected to last another 40 years, but replacement or renovation may be needed sooner than anticipated due to factors such as climate change and societal developments. Yet, there is relatively little known about what factors and how these factors influence the remaining life, and methods that can be used to estimate the remaining life of the barrier are lacking. This thesis aims to identify the dominant factors and associated uncertainties affecting the remaining life and to provide a method for the estimation of the remaining life of the Hollandsche IJssel storm surge barrier. The focus of the study is on the functional and technical life of the barrier.

First, the functions and structural components of the storm surge barrier were identified. For each function, requirements were formulated to support the evaluation of the impact of the external drivers. The physical decomposition of the storm surge barrier was needed to identify the dominant deterioration mechanisms. This analysis revealed that the technical life is not governing for the total remaining life of the barrier. Therefore, the focus should mainly be on the functional life of the storm surge barrier. Next, the impact of external drivers on the functional performance or technical state of the barrier was evaluated by a semi-quantitative analysis in which scenarios with the projected changes were used. The study identified sea level rise as the dominant (physical) driver affecting the remaining life of the storm surge barrier because of the potentially large future changes and far-reaching consequences.

By combining the required performance levels expressed as critical amounts of sea level rise with various sea level rise projections, estimates of the remaining life of the Hollandsche IJssel barrier were obtained. It was found that even for moderate sea level rise scenarios, there is a significant probability that the end of life of the barrier could be reached within 20 years. The estimates of the remaining life of the barrier are, however, uncertain, and a considerably longer lifespan cannot be ruled out. Accordingly, it is recommended to investigate possible measures to lengthen the lifespan and determine the best moment in time to implement these measures. The decision to implement specific measures will be dependent on the costs and benefits. Economic considerations should therefore be included as well. Furthermore, a more system-oriented approach is recommended for this kind of analysis since modifications to a certain object could impact other elements within the system, e.g. dike reinforcements affect the required closure reliability of the storm surge barrier. Finally, a more general recommendation is to perform similar studies for other critical structures as the remaining life of those structures may also be reached sooner than anticipated if, for example, functional aspects are taken into account.

Being one of the world’s largest waste generator, the construction industry is responsible for a train of events such as global warming, climate change, and depletion of natural resources. Materials are exhausted globally to a large extent and the waste produced in the process is not treated properly. A “take-make-dispose” or popularly known as linear economy is the process that is adopted to treat the waste currently, where large quantities of resources end up as waste after demolition of the building. This grabs our attention towards the concept of Circular Economy (CE) with the goal to potentially minimize the pending issues arising from the construction sector through recirculation of building materials. However, due to the unfamiliarity of its economic feasibility, many are still reluctant for investing in circularity as they believe circular construction to be more expensive. The main challenge is to overcome the lack of understanding of the available circular strategies and their effect on their business. Therefore, the objective of this research is to investigate how buildings can be made more circular. Furthermore, the aim is to compare the alternatives based on the life cycle costs and a circularity measure, so that stakeholders are in a better position to invest/favor circularity in general. Finally, the objective is to present a way to invest in circular projects by merging the methods used in this study.

Firstly, literature review was conducted to develop a better understanding of the most important concepts in relation to this research. It reveals the need for several methods to conduct the research, and hence three methods are further elaborated. An inventory of possible circular interventions was made and categorized based on strategies and layers of the building. The methods discussed were applied to a case study. The application of interventions on the base case intends to gradually increase the circularity of the building. This gradual increase in circularity calls for a comparison of a traditional building with its circular twin. Based on the analysis, it can be concluded that a comparison as such can help in a parallel tracking of both circularity level and life cycle costs of a building, which in turn aids in taking both the factors into account for decision making. Thus, both the costs and circularity of a building are quantified.

The main findings are: A building can be made more circular by searching for circular activities that can replace a non-circular activity by using a circular strategy framework- in this case, R-strategy was used. The application of circular activities or interventions can be categorized layer-wise to carefully examine the impact of the activity on the circulatory level and costs associated with the building. This can be done by diving the building into different layers- in this case, Stewart Brand layers was used. The circularity of the building is to be increased gradually. Further, several alternatives can be generated to analyze the best-case scenario that can justify both the circularity and cost of a building. This is done by using a circularity measure and life cycle costing- in this case, material circularity index and discounted cash flow analysis were used respectively. Finally, the results can be analyzed by quantifying both circularity and cost. This makes sure circularity in a building is not compromised for the costs associated with the building. This way, stakeholders are better aware of the opportunities and can make better decisions in selecting circular projects which could lead to enhance the acceptance of circularity within the building sector.

Dynamic traffic management (DTM) plays an important role from Dutch policy perspective to prevent road congestion and has been developed from control strategies to services. Five traffic control centers, 22 different DTM systems with 35 functions and over 50,000 DTM components make up the national traffic management network in the Netherlands. The malfunctioning of the DTM systems is expected to create negative impacts to the traffic, proper maintenance planning is necessary to ensure their availabilities. However, there is less knowledge about the DTM malfunctions, which makes it difficult to monetize the malfunction effects and therefore to optimally deploy the maintenance budget. In this research, a macroscopic dynamic traffic assignment model “MARPLE” is used to evaluate the social costs of the DTM malfunctions according to the failure function, failure duration, and failure location.
The motorway network around Amsterdam is chosen as the study area in this research, and four DTM systems and measures were evaluated, including the rush hour lane (RHL), the motorway traffic management (MTM) system, the dynamic route information panels (DRIPs) and the ramp metering (RM) system. By conversing the DTM malfunctions into the motorway network, the introduced impacts to the traffic both in local and network levels are identified.
This research made the first attempt to modify DTM malfunctions in a macroscopic dynamic traffic assignment model, and a methodology was developed to calculate the malfunction costs both in traffic flow and safety aspects. The outcome of this research answered what-if questions with regarding to DTM malfunctions, it also proved the feasibility of the ambition to translate the DTM malfunction impacts at a network level into its social costs, according to which the maintenance strategy for the DTM systems can be better deployed. Overall, the initial goal of calculating the malfunction costs of the DTM systems with a newly developed methodology is met. Through the identified limitations and improvement strategies, the framework developed in this study could offer the possibility to refine the analysis, and/or easily be applied to other DTM systems and road parts.

Maturity model has proven to be helpful for an organization to identify its current capability, strength, and weaknesses through maturity levels. These levels are used to rank the various dimension or process of an organization. However, maturity levels only describe a general description of organization capability. The effect of different maturity levels towards the organizational outcomes is speculated in the basis of the description at each maturity levels. The use of the maturity levels is limited in the pre-determined description. This research is an attempt to foresee the effect of different management maturity towards asset cost and performance by using Dynamic Bayesian Network. The network is developed by using a semi-hypothetical case on grass revetment management. The network models the maintenance process which covers the asset degradation and the influence of different extent of management towards grass condition in time. The degradation probability was determined by using Cooke’s classical model expert judgment. We designed different network involving four management dimension that was translated as model scenarios. The result provides an insight into the potential gain or loss of different management maturity which is beneficial for organizations in evaluating different alternatives of management improvement.

Infrastructures have become important for the holistic growth of any country. With the number of such projects being constantly on the rise each year, its efficient maintenance has become a primary requirement for any asset owner. Among the many techniques available, FMECA is widely used for maintenance planning. In this method, different critical components are identified based on their likelihood of failure and impact on the infrastructure. Based on the inferences obtained, maintenance plans are developed where interventions are prioritized based on a component’s criticality within the system. FMECA uses risk matrices to assess criticalities semi-quantitatively. This lacks the required quantifiable information of a component in a system. A component by design can either be individual or exist as a subsystem comprising several components. To analyze criticalities accurately, quantitative information that can provide insights on a component’s state in the system is required. Hence, this thesis develops a new approach that could eliminate subjective errors in conventional criticality analysis. The new and conventional approach was applied to two infrastructures to observe and discuss the variations in results obtained. The comparative study showcased that the new approach provided better quantitative reasonings for criticalities obtained for each component. Using the unique implementation of the obtained quantitative data as done in the current research, developing realistic and accurate maintenance strategies is possible.

Internal and external uncertainties like structural integrity, load, demand, weather conditions and spatial planning have an impact on Infrastructure assets. Incorporating uncertainties and flexibility to decisions by means of more information becoming available, adds value to new investments, life time extended maintenance and replacements. The traditional way to evaluate such projects, the Life Cycle Cost Analysis (LCCA) based on traditional Net Present Value (NPV) techniques fails to incorporate flexibility, and hence ignores extra value from expected future information. Decision Tree Analysis (DTA) and Monte Carlo Analysis (MCA) can actually allow for valuing flexibility in investments.
If investments are subject to non-diversifiable uncertainties, investors should be compensated for associated risks by using time dependent risk adjusted discount rates for valuation practices. A discussion is taking place on difficulties that occur if this principle is applied to infrastructure investments. Conducted literature research shows that current techniques to correct for non-diversifiable cannot be applied directly to most engineering valuation problems.
A MCA on investment alternatives regarding to the replacement of a bridge in the municipality of Amsterdam demonstrates how expected investment values can be calculated taking along multiple uncertainties and flexibility. Although the value of flexibility is always equal or greater than zero, case study results show that incorporating uncertainty and flexibility in the analysis can also affect the NPV negatively.