There is a gap in the discourse between urban designers and civil engineers, within the field of urban water management. The gap is caused by the different educational background, perspective, approach and language used in the respective fields. It causes multidisciplinary projects like the redevelopment of Schieoevers Noord in Delft to be unnecessarily difficult or inefficient.

This thesis studied the effect of the gap in discourse on the redevelopment plans of Schieoevers Noord, with the aim of bridging the gap and making the plans more water inclusive. To achieve that, the area and plans were thoroughly analysed and research was done into the principles behind healthy surface water systems in the Netherlands and climate adaptation measures. Using the data from these analysis five evaluation criteria were set up.

Next using the principles of water management and the climate analysis of Schieoevers Noord, four strategies for an improved water system in the area were made. The evaluation criteria helped define the strengths and weaknesses of these strategies. This made it possible to take the strong points and combine them into a final proposal for the water system in Schieoevers Noord. The proposal was also tested using the evaluation criteria and the results showed that it held up really well in all categories.    

The lessons learned from going through this process for Schieoevers Noord, are that bridging the gap between urban designers and civil engineers within urban water management is achievable. But it requires effort from both parties to go back and forth between the two fields, while using existing tools to ease communication. A very useful tool for this would be the Climate Resilient Cities Toolbox. With some further research into quantifying design goals this toolbox can be improved even more, and therefore become a great tool for bridging the gap between the two fields.

Another important lesson learned from this research is the importance of thinking about the water system in a very early stage of the planning process. Surface water systems are often complex and adding to them will take up a large amount of space. However, a healthy surface water system is more efficient than only using climate adaptation measure, when combatting the negative externalities of climate change. Because the effects of climate change are rapidly increasing, it is imperative that developers, municipalities and other stakeholders prioritise healthy water systems in their development plans.

Climate change is affecting the urban environment in the Netherlands, which increases the risks of droughts, floods, waterlogging, and heatwaves. Consequently, the cities we build many years ago are not resilient to climate change in the long run. In response the national government created the Delta Plan on Spatial Adaptation (DPRA) to adapt to the new situation and achieve a climate-proof and water robust urban environment. Climate change adaptation requires a local approach as the climate change effects can differ per neighbourhood. Therefore, local governments are in charge to implement the DPRA. Since the urban environment consists of both public and private space, the involved stakeholders will have to collaborate to ensure a climate-proof environment. Meaning they have to agree on their roles and responsibilities to adapt. Yet, in reality this is not always the case. In this research, the Q methodology is used to find the different perspectives of sixteen public and private stakeholders in two neighbourhoods of The Hague. Next, stakeholders with different perspectives are invited to participate in a risk dialogue (the second ambition of the DPRA). Using the constructive conflict methodology, the effect of the dialogue is analysed. This research did not bring the perspectives closer together, which entails that public stakeholders might have to limit their expectations to increase the perceived responsibility of private stakeholders using the risk dialogue. However, public stakeholders can apply the method of this study to improve their knowledge of the differences in perspectives during the dialogue, their preparation of arguments, and analyse the effect of the dialogue.

Due to the predicted impacts of climate change on the frequency of storm events, water managers are challenged to improve and adapt the current urban infrastructure. Cities need to be able to deal with the adverse effects due to more frequent and heavier rainfall. This implies the need for sustainable urban drainage systems (SUDS) that can deal with these challenges. SUDS can be seen as designs that can improve both, the quantitative as well as qualitative characteristics of stormwater. The study area in the south of Amsterdam will be equipped with a SUDS, namely a SediSubstrator L by Fränkische Rohrwerke. The objective is to remove particles from stormwater discharge to prevent clogging of the infiltration facility (AquaBASE) installed in sequence. Additionally, it can remove harmful pollutants which are adsorbed to the fine particles.
This research aims to investigate the characteristics of the sediments in stormwater in theory and develop an appropriate sampling strategy to monitor the relevant parameters in the field. The long-term objective hereby is to determine the removal efficiency of the SediSubstrator L using a finite amount of parameters. To do so, a threefold approach composed by a detailed literature review, stormwater sediment sampling as well as a model simulation was used.
Based on the identified parameters to be assessed, a specific monitoring and sampling setup is proposed to determine the removal efficiency of stormwater sediments in the study area. Along with the efficiency, the volume of sediments that are caught by the facility can be approximated. The latter needs to be removed once the entire storage volume of the sedimentation facility is filled. It is recommended that Waternet uses measured stormwater data to improve the model, while monitoring the efficiency under field conditions. Once the results of the model and the actual field measurements match, the model can be used to simulate the sediment removal for long time series. In this way the cleaning intervals can be predicted, while avoiding expensive long-term measurements to do so.

Shanghai is one of the numerous megacities worldwide that experience severe flood events triggered by torrential rainfall. To deal with the undesirable consequences of these events and mitigate the flood hazard, the research of flood reduction measures is necessary. In this effort, the hydrodynamic modelling is a useful tool.
In this master thesis a 2D model was developed for the simulation of urban flood events in Jingan District in the downtown of Shanghai. The main objectives of the thesis were the production of the flood hazard maps for numerous rainfall events and the assessment of the proposed flood mitigation measures. Delft3D Flexible Mesh was used as a tool to produce the inundation maps. Also, several data were considered regarding the grid for the numerical calculation, the surface elevation, the local drainage system and the rainfall events. SOBEK was used for the set up and the preprocessing of the sewer system. For the simulations, data from three historical rainfall events were used: August 2005, August 1997 and September 2013 and five rainfall events with return periods of 1, 3, 5, 10 and 50 years were generated by using the Chicago hydrograph.
For the validation of the model, the rainfall event of August 2005 was used. Although the validation of the model was not proven due to the simplifications that were made in the input data and the lack of data, the model showed that some processes can be simulated, and inundation maps can be produced. By comparing the results that occur with and without the inclusion of the drainage system, it was concluded that the local drainage system should be included in the analysis for the assessment of the flood hazard in an urban area, since its presence plays an important role in the flood reduction. The results showed that the maximum inundation depth can decrease by around 45%. As flood reduction measures, the creation of water storage areas and the increase of the drainage capacity were considered. The water storage areas covered around 10%, or less, of the block areas with available space, leading to a water depth reduction that depends on the location in the map. For the increase of the drainage capacity, the value of 1 m3/s was assigned in a single and in multiple locations in a specific area of investigation. The results showed a percentage of water depth reduction around 15.9% and 45.5%, respectively. For the same location the percentage of water depth reduction due to the water storage areas was 22.5%.
Finally, uncertainties were introduced in the model due to the assumptions and the simplifications that were made in the input data. However, this model can work as a base for future researches to accomplish more realistic results, by improving the current model and adding more updated and precise data.

Biofilters are increasingly being implemented in urban environments to treat stormwater but knowledge on their pathogen removal capacity at field scale is limited. Adequate pathogen removal is, however, needed if treated water is reused. This research evaluates the fate of Escherichia coli, enterococci and Campylobacter in a field scale biofilter in Rotterdam. This biofilter is part of the Urban Waterbuffer Spangen that combines biofiltration with Aquifer Storage and Recovery (ASR) to provide irrigation water for Sparta’s sports field. Microbiological water quality was analysed to assess the removal capacity of the biofilter. To identify factors causing adverse treatment performance, system construction, and operation were investigated, water flows in the biofilter were assessed, and hydraulic conductivity was measured. Lastly, model simulations were used to investigate how short-circuiting and event frequency and duration affect microbiological outflow concentrations. Results showed leaching of enterococci and Campylobacter and minimal retention of Escherichia coli. Leaching is likely caused by secondary contamination with bird faeces and multiple design and operational choices lead to low microbial retention. Coarse filter media results in high hydraulic conductivity, and consequently, short hydraulic retention times. Electrical conductivity measurements revealed short-circuiting pathways between the inlet and outlet. Lastly, uneven distribution of feed water presumably reduced the effective reactor volume. It is recommended to upgrade biofilter design by incorporating small particles in the filter media and maximizing the distance between the inlet and outlet. Additionally, reintroduce a ponding zone and rearranging event frequency and duration to lower microbial outflow loads is advised. Model simulations suggest that short, frequent events are beneficial to control microbial loads. However, further work to clarify microbial decay rates is recommended. To conclude, results imply that the biofilter is currently unable to improve the microbiological water quality but can become a treatment barrier if design and operation are upgraded to tackle encountered problems.

In the Netherlands, the Delta Programme aspires to adjust spatial planning climate-proof and water-resilient, in order to be prepared for extreme weather in 2050. To achieve this ambition, municipalities, provinces, regional water authorities and central governments conduct stress tests to map out the vulnerabilities in their areas of authority by no later than 2019. The stress tests comprise four themes: pluvial flooding, drought, heat and floods. In addition, the Delta Programme 2019 acknowledges the mitigation of and adaptation to land subsidence as an important tasking. The municipality of Rotterdam faces the challenge of adding land subsidence as stress test theme and assessing its influence on pluvial flooding. Contrary to the stress test pluvial flooding, no consended methodology exist on how to map out vulnerabilities concerning land subsidence. In addition, only few studies have numerically investigated the spatial-temporal effect of land subsidence on pluvial flooding in urban areas. However, the advent of techniques to measure ground level (LiDAR) and land subsidence (InSAR) and advances in high resolution flood modelling (3Di) enable the numerical modelling of urban pluvial flooding influenced by land subsidence. This research explores the investigation of the influence of land subsidence on pluvial flooding in Rotterdam by supplementing the conducted stress test pluvial flooding with a land subsidence assessment. The conducted stress test pluvial flooding in Rotterdam is based on a 3Di-simulation of standardised rain events, based on a DEM 2016.

To asses the current influence of land subsidence on pluvial flooding, a Digital Elevation Model (DEM) that approximates the sub-neighbourhood Tuinenhoven at design level is created and used as 3Di-input. When comparing 3Di-results based on this design DEM to the stress test pluvial flooding, it becomes clear that the total volume of water during extreme rainfall stored on the streets is not affected by land subsidence. The bathymetry of the DEM does affect the water's distribution however. The Tuinenhoven case-study demonstrates that currently land subsidence increases the severity of the impact of pluvial flooding but that the main cause of pluvial flooding during extreme rainfall is the limited capacity of the drainage system.

Land subsidence in Rotterdam complex. The conducted land subsidence analysis based on an InSAR data-set supports this complexity. It illustrates that the subsidence behaviour of Rotterdam is influenced by foundation type, land use classification, the presence of dredge in the anthropogenic layer and top soil type. This respectively indicates the occurrence of pole rot and shallow foundations, anthropogenic compression and compaction of shallow soft layers caused by loading, landfill subsidence as a result of land fillings that contain dredging spoil and consolidation of the Holocene clay layer as a result of drainage. However, the land subsidence analysis failed to identify location-specific dominant land subsidence processes. This failure was primarily caused by the limitation to only one linear subsidence rate between 2009 and 2014 per point. To demonstrate how land subsidence can be translated to pluvial flooding based on a land subsidence analysis, land use classification was selected as the most dominant influencing factor and used in a linear land subsidence prognosis until 2030. The linear assumptions largely obstructs results to be interpreted location-specific.

The IJsselmonde case-study shows that land subsidence is expected to decrease the passability of roads and decrease the risk per building in the future. These decreases are caused by the fact that roads relatively subside fast and buildings relatively slow. The biggest influence on the risk per building classification is the assumed threshold value per building. Simulated road maintenance results in an increase of the passability of roads and an increase of buildings at risk of water nuisance. The loss of the water-storing function of the road after reconstruction increases the water levels in gardens and puts buildings at an increasing risk.

In conclusion, the most challenging part of investigating the influence of land subsidence on pluvial flooding is the crucial identification of the different occurring land subsidence processes. It is demonstrated that the possibilities with InSAR-data are promising, when used with sufficient competency, although the available InSAR data should be divided in shorter intervals to detect the subsidence rate trends. Land subsidence rate trends are crucial in the identification of land subsidence processes and assessing influences like groundwater variations and increased loading due to maintenance or construction works. When the land subsidence analysis is improved, so will the land subsidence and threshold height per building prognosis. When the relative prognosed decrease of the threshold value per building is improved, it can be quickly assessed whether buildings classified at risk in the stress test pluvial flooding are at future increasing risk during extreme rainfall, without conducting a full 3Di-simulation.

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.

In recent years, urban inundation modelling has been stimulated by technological advancements and an increase in data availability and quality. Diminution of modelling restrictions allowed for detailed methodologies, yet escalated the number of required parameters, leading to higher complexity and predictions’ uncertainty issues. In the present study, two state-of-the-art models with distinct numerical discretisation strategies, schematisation and rainfall runoff modules, namely MIKE FLOOD and D-Flow FM are evaluated in urban fluvial and pluvial inundation. The case study of Colombo Metropolitan region (Sri Lanka) is used. Dominant factors interpreting models’ differentiations are identified and further analysed. Results suggest that D-Flow FM concept is more realistic and sensitive to overland surface information but require higher detail and computational times compared to MIKE FLOOD methodology. The outcome of this research is anticipated to aid modellers in choosing the most appropriate model principle based on the data availability, desired accuracy and computational time.

Dit onderzoek is uitgevoerd om meer inzicht te verkrijgen over de de invloed van ondergrondse waterberging (owb) systemen op warmte- koudeopslag (wko) systemen. Meer specifiek is er onderzoek gedaan naar de situatie in Utrecht. In Utrecht zijn meerdere wko-systemen aanwezig en de Gemeente heeft plannen geformuleerd om in de buurt hiervan een plantsoen aan te leggen om hemelwater op te vangen en in de ondergrond te bergen. In deze studie is de invloed van deze owb op de omliggende wko-systemen onderzocht. Bij het bepalen van de invloed van een owb-systeem is zijn de neerslag- en ontwerp dimensies variabel.

Het onderzoek is gestart met de inventarisatie van de bodem in Utrecht. Hierbij is gekeken naar eigenschappen die van belang zijn voor de toepassing van beiden systemen. De bodem in Utrecht is opgebouwd uit twee verschillende typen lagen: de scheidende klei- en veenlagen en de watervoerende zandpakketten (aquifers). De dikte van de eerste scheidende laag is ca. 4 meter en de dikte van de eerste aquifer is ca. 40 meter. Met deze opbouw kan water in de aquifer worden geborgen zonder dat dit voor wateroverlast op het maaiveld (mv) zorgt.

De bodemenergiesystemen rondom het plantsoen betreffen die van de Jaarbeurs en de Rabobank. De omvang van de bron (het volume in de aquifer waar warme of koude wordt opgeslagen) is onderverdeeld in de thermische- en de hydraulische omvang en de vorm is cilindervormig beschouwd.
Alle bronnen hebben een filterlengte van 18 meter die begint op 8 meter -mv. De grootte van de type bronnen en de grondwaterstromingsrichting verschillen per seizoen door de warmte- en koude vraag en beschikbaarheid.

Voor de ondergrondse waterberging zijn de KNMI-neerslaggegevens van de Bilt sinds 2000 geanalyseerd en is het gemiddelde neerslag per meteorologisch seizoen bepaald. Het percentage hiervan dat beschikbaar komt voor owb is op basis van drie verschillende scenario’s bepaald met als variabelen het verharde oppervlakte en het percentage van de neerslag dat op verhard oppervlakte
valt én naar het owb-systeem wordt geleid. Voor iedere scenario is de minimale afstand tussen de owb-bron en de wko-systemen bepaald aan de hand van (1) de hydraulische straal, (2) de zuurstof spreiding en (3) de radiaal afgelegde afstand van het infiltratiewater. De afgelegde afstand van het infiltratiewater is bepaald op de tijd die nodig is voor de bodem om alle zuurstof om te zetten op 25 meter van de put. De grootste waarde van (1), (2) en (3) is maatgevend genomen.

Uit de resultaten van het onderzoek blijkt de hydraulische straal van de owb in geen enkel scenario te overlappen met de wko-bronnen. Dit geldt ook voor de zuurstofspreiding op basis van zowel een lineair- als een exponentieel verband tussen de zuurstofconcentratie en afstand van de owb-put.
Afhankelijk van de ontwerpdimensies en het scenario overlapt de radiale afstand afgelegd door het infiltratiewater wel met de wko-bronnen en wordt de installatie van een owb-systeem afgeraden.