Ce travail de thèse a évalué les niveaux et les voies d'introduction de la contamination en micropolluants des eaux pluviales d'un petit bassin versant urbain, et mis en évidence les impacts de l'utilisation de techniques alternatives (TA) sur les flux d'eau et de contaminants. Quatre bassins versants à Noisy-le-Grand, homogènes par leur taille et leur occupation du sol (1 à 2 ha, résidentiel dense), et présentant une diversité de gestion des eaux pluviales (séparatif classique et différentes combinaisons de TA) ont été étudiés. La présence d'un certain nombre de substances prioritaires de la directive cadre européenne sur l'eau (HAP, alkylphénols, phtalates, diuron, isoproturon, atrazine, plomb) a été mise en évidence dans les eaux pluviales d'un bassin versant amont, à des niveaux de contamination globalement plus faibles qu'à l'aval des réseaux séparatifs. Cette contamination est tout de même significative pour certains paramètres qui ont été mesurés au dessus des normes de qualité. Pour le zinc, la contamination à l'amont est même plus élevée qu'à l'aval du fait de l'émission par des matériaux de couverture.Ce travail a montré que les TA diminuent les volumes d'eau rejetés vers l'aval d'environ 50% et réduisent les masses de contaminants émises de 20 à 80% (MES, DCO, PCB, HAP, alkylphénols, métaux traces). Cette réduction de masse est essentiellement liée à la diminution de volume, l'effet épuratoire sur les concentrations n'étant pas systématiquement mis en évidence. L'amplitude de ces effets varie suivant l'importance de la pluie, mais surtout en fonction du type d'ouvrage mis en place.La gestion à l'amont des eaux pluviales est donc à favoriser car elle évite la sur-contamination liée aux processus en réseau (mauvais branchements, érosion...). Elle permet de séparer les eaux peu chargées (infiltration ou rejet au milieu) des effluents contaminés qui pourront être traités localement ou à l'aval. Dans un objectif de réduction des flux polluants la conception des TA devra prendre en compte les pluies courantes et non pas seulement les événements exceptionnels / This thesis aimed at evaluating the contamination of urban stormwater from an upstream watershed by micropollutants and their introduction pathways, and estimating the hydrological effects and the pollutant removal performances of Sustainable Urban Drainage Systems (SUDS). Four watersheds located in Noisy-le-Grand were studied. They had comparable sizes (1 to 2 ha) and land use patterns (dense residential), but one was drained by a classical separate sewers system, and the other was managed by SUDS.We showed that stormwater from an upstream watershed is contaminated by some priority substances of the Water Framework Directive (PAHs, alkylphenols, phtalates, diuron, isoproturon, atrazine, lead), but at lower levels than the downstream. The concentrations of some parameters still excede the quality standards. Zinc concentrations are even higher than downstream, as a result of emissions from metallic materials from roong.SUDS reduce the volume of surface water discharged by 50 %. The mass of contaminants also decreases by 20 to 80 % (SS, COS, PCB, PAH, alkylphenol, metals). The discharge reduction is mainly due to water losses, whereas removal performances on concentrations are not systematically highlighted. These effects vary with rainfall and particularly with the type of SUDS.The upstream management of stormwater should be encouraged to avoid over contamination due to processes in sewer systems (erosion, bad connections...). Lightly contaminated effluents (infiltration or discharge to middle) can be separated from strongly contaminated ones that can be treated locally or downstream. In order to integrate depollution goals, the design of SUDS, currently based on exceptional events, should also rely on frequent events

Os sistemas relacionados à gestão e manejo dos recursos hídricos são concebidos e operados em todo o mundo considerando, dentre outras, a hipótese da estacionariedade da precipitação. Sob a hipótese da não estacionariedade, o possível aumento na magnitude e frequência de eventos extremos pode reduzir o nível de proteção das obras hidráulicas e acarretar em prejuízos econômicos, sociais e ambientais significativos. Em metrópoles como São Paulo, onde as bacias hidrográficas sofreram grandes transformações, o aumento da vulnerabilidade da infraestrutura hídrica, como os sistemas de drenagem, pode representar um risco ainda maior. Inserido neste contexto, esta pesquisa possui o objetivo de verificar se a precipitação na cidade de São Paulo apresenta um comportamento não estacionário e quais seriam as suas implicações sobre estudos hidrológicos, projetos de engenharia e custo de obras. Os testes não paramétricos de Mann-Kendall e Mann-Whitney foram aplicados para a detecção de mudanças graduais e abruptas respectivamente. A distribuição generalizada de valores extremos foi ajustada para identificação e quantificação das mudanças na magnitude e frequência da precipitação. A partir dos registros de precipitação em seis postos pluviométricos localizados na cidade de São Paulo, o comportamento não estacionário foi identificado em três séries de precipitação total anual e em duas séries de precipitação máxima diária anual. Para um aumento na precipitação de 9,5% entre 1997 e 2012, o aumento do escoamento superficial é superior a 28% para os tempos de retorno entre 10 e 100 anos. Esta mudança na precipitação pode acarretar em um aumento dos custos das obras de sistemas de micro e macrodrenagem entre 6% e 11%. / Water resources systems are planned and managed under rainfall stationarity hypothesis. Under non-stationarity, possible extreme precipitation magnitude and frequency increase may reduce water structures risk protection and cause several significant economic, social and environmental damage. In metropolises such as São Paulo, water infrastructure vulnerability increase may represent an even important risk, especially of flooding. In this context, this paper aims to verify in the city of São Paulo, if rainfall time series follow a non-stationary behavior and what would be its implications of hydrologic studies, engineering projects and work costs. Mann-Kendall and Mann-Whitney non-parametric tests were performed to detect changes gradually and in moments respectively. GEV distribution was fitted to identify and quantify changes in rainfall magnitude and frequency. From six rainfall series recorded in rain gauges in São Paulo city, non-stationarity was identified in three series of annual total and two of annual maximum daily precipitation. For an observed increase of total precipitation of 9.5% between 1997 and 2012, runoff increases in more than 28% for return periods between 10 and 100 years. This change of rainfall may increase work cost of minor and major drainage systems between 6% to 11%.

Os sistemas relacionados à gestão e manejo dos recursos hídricos são concebidos e operados em todo o mundo considerando, dentre outras, a hipótese da estacionariedade da precipitação. Sob a hipótese da não estacionariedade, o possível aumento na magnitude e frequência de eventos extremos pode reduzir o nível de proteção das obras hidráulicas e acarretar em prejuízos econômicos, sociais e ambientais significativos. Em metrópoles como São Paulo, onde as bacias hidrográficas sofreram grandes transformações, o aumento da vulnerabilidade da infraestrutura hídrica, como os sistemas de drenagem, pode representar um risco ainda maior. Inserido neste contexto, esta pesquisa possui o objetivo de verificar se a precipitação na cidade de São Paulo apresenta um comportamento não estacionário e quais seriam as suas implicações sobre estudos hidrológicos, projetos de engenharia e custo de obras. Os testes não paramétricos de Mann-Kendall e Mann-Whitney foram aplicados para a detecção de mudanças graduais e abruptas respectivamente. A distribuição generalizada de valores extremos foi ajustada para identificação e quantificação das mudanças na magnitude e frequência da precipitação. A partir dos registros de precipitação em seis postos pluviométricos localizados na cidade de São Paulo, o comportamento não estacionário foi identificado em três séries de precipitação total anual e em duas séries de precipitação máxima diária anual. Para um aumento na precipitação de 9,5% entre 1997 e 2012, o aumento do escoamento superficial é superior a 28% para os tempos de retorno entre 10 e 100 anos. Esta mudança na precipitação pode acarretar em um aumento dos custos das obras de sistemas de micro e macrodrenagem entre 6% e 11%. / Water resources systems are planned and managed under rainfall stationarity hypothesis. Under non-stationarity, possible extreme precipitation magnitude and frequency increase may reduce water structures risk protection and cause several significant economic, social and environmental damage. In metropolises such as São Paulo, water infrastructure vulnerability increase may represent an even important risk, especially of flooding. In this context, this paper aims to verify in the city of São Paulo, if rainfall time series follow a non-stationary behavior and what would be its implications of hydrologic studies, engineering projects and work costs. Mann-Kendall and Mann-Whitney non-parametric tests were performed to detect changes gradually and in moments respectively. GEV distribution was fitted to identify and quantify changes in rainfall magnitude and frequency. From six rainfall series recorded in rain gauges in São Paulo city, non-stationarity was identified in three series of annual total and two of annual maximum daily precipitation. For an observed increase of total precipitation of 9.5% between 1997 and 2012, runoff increases in more than 28% for return periods between 10 and 100 years. This change of rainfall may increase work cost of minor and major drainage systems between 6% to 11%.

Dagens dagvattenhantering i urbana områden är inte hållbar vilket resulterar i översvämningar, förfallav naturen och hälsoproblem. Fortsatt urbanisering och klimatförändringar påverkar systemet negativtoch kräver en brådskande förändring. Ett alternativ till traditionell dagvattenhantering är naturligalösningar, NBS, definierat som inspiration och användandet av naturen för att hanterasamhällsproblem. Det kan ge resilienta och adaptiva lösningar som främjar biologisk mångfald,människors välbefinnande, ett lovande alternativ för att tackla de här problemen. NBS är dock förenatmed osäkerheter såsom kunskapsbrister kring prestanda, underhåll och möjliga negativakonsekvenser. Även om NBS kan anses vara en hållbar lösning är den inte frekvent implementerad iurbana områden. Den här uppsatsen använder fallstudien Årstafältet för att samla och analysera föroch nackdelar av NBS och traditionella dagvattenlösningar. Med hjälp av intervjuer med inblandadeaktörer, plandokument, regleringar och en litteraturstudie visar resultatet att NBS kan ge ett resilient,flexibelt och kostnads-effektivt system med multipla fördelar vilket kan uppfylla t.ex. vattendirektivet(WFD), hållbarhetsmålen (SDGs) och miljömålen. Det traditionella systemet är en oelastisk lösninginkapabel att förebygga miljöförändringarna och med frekvent breddning av smutsigt dag- ochavloppsvatten. Systemet är sett som oförmögen att uppfylla mål kring biologisk mångfald, miljömåloch reningskrav och därav en ohållbar lösning. Existerande infrastruktur och ett välarbetat arbetssättgör att det traditionella systemet dock fortfarande förlitas på. Problem som identifierades med NBSvar kunskapsbrister, en ny process för att hantera dagvatten som inkluderar en omfattande inblandningav aktörer, övergångsbarriärer, oklarheter gällande ansvarsfördelning, brist på deltagande frånallmänheten, avsaknad av tekniskt vägledning, bristen och behovet av att kontrollera och mätalösningar samt beroendet av entusiastiska aktörer. / The current stormwater management in urban areas is not sustainable, resulting in frequent floodingevents, degeneration of the environment and human health issues. Increased urbanization and climatechange negatively impact the outcome and calls for an urgent change. An alternative to traditionalstormwater management is nature-based solution, NBS, broadly defined as the usage or inspiration ofnature to address societal challenges. It can provide resilient, adaptive solutions which promotebiodiversity and human well-being, a solution to address these challenges. NBS is however unitedwith uncertainties such as knowledge gaps of performance, maintenance, efficiency and potentialtradeoffs. Although NBS can be considered a sustainable solution, it is not widely adopted andimplemented in urban areas. This thesis uses the case study of Årstafältet project to identify andanalyze opportunities and challenges of NBS and conventional drainage system. Based on interviewswith involved actors, plans, regulation and a conceptual framework, the result shows that NBS canprovide a resilient, flexible and cost-effective system with multiple benefits which addresses allaspects of sustainability. It is widely supported by laws and policies, addressing the EU WaterFramework Directive (WFD), the Sustainable Development Goals (SDGs) and the EnvironmentalObjectives for example. The conventional drainage system is an inflexible system unable to mitigateclimate change, with frequent overflows (CSOs) of dirty storm and sewage water. It is unable toachieve biodiversity goals, environmental objectives and water quality targets and thus recognized asan unsustainable solution. With an existing infrastructure and an established way of managing theconventional drainage system, it is however still relied on. Identified challenges of NBS areknowledge gaps, a new management process with extensive stakeholder involvement, transitionbarriers, unclear division of responsibilities, lack of public participation and technical guidance, lackof and the need to monitor solutions and the dependence on enthusiastic actors.

Urban drainage systems are influenced by several future drivers that affect the performance as well as the costs of the systems. The uncertainties associated with future drivers and their impact creates difficulties in designing urban drainage systems sustainably. A review of the different future drivers for urban drainage systems illustrates that no sufficient future predictions for the long operational life spans of the systems are possible. This dissertation contends that to deal with future uncertainties, flexibility in urban drainage systems is necessary. At present, profound insights about defining, measuring, and generating flexible urban drainage systems do not exist. This research systematically approaches these issues. First, a clear definition of flexibility and an approach for the measurement and optimization of flexibility is operationalized. Based on the generic definitions of flexibility used in other disciplines, a definition tailored for urban drainage systems is generated. As such, flexibility in sustainable urban drainage systems is defined as `the ability of urban drainage systems to use their active capacity to act and respond to relevant alterations during operation in a performance-efficient, timely, and cost-effective way'. Next, a method for measuring flexibility is provided based on the developed definition of flexibility including the metrics, 'range of change', 'life-cycle performance' and 'effort of change'. These metrics are integrated into a framework for the measurement of flexibility based on a comparison of performance and effort in different alternative solution with respect to different future states. In addition the metrics are the core components for optimizing flexible design of urban drainage system. The measurement method is successfully applied in two case studies in Tuttle Hill, UK and Hamburg-Wilhelmsburg, Germany. Using the developed definition and method for the measurement of flexibility, this dissertation illustrates that a transfer of the general theoretical background of flexibility to the field of urban drainage is possible. It is currently unclear how the flexible design of urban drainage systems can be executed. Based on a review, this research identifies nine potential principles of flexible design, described by the indicators of modularity, platform design, flexible elements, cost efficiency, decentralized design, real time control, low degree of specialization, scalability, and a combination of these principles. A case study of Hamburg-Boberg is then presented to analyze which of these principles of flexible design can be verified. For each alternative solution in the sample, the indicators for the different potential principles of flexible design as well as the flexibility provided by the design are calculated. Testing is done to determine if there is a significant correlation between the potential principles of flexible design and the measured flexibility using a chi-square-test and F-test. Two principles are verified with a high degree of confidence, 'platform design' and `flexible elements'. The `platform design' principle provides high flexibility, in which urban drainage system elements with high change costs are designed robustly with huge tolerance margins, whereas elements with low change costs are designed with flexibility options. The 'flexible elements' principle aims to include as many component elements as possible, which provides high individual flexibility in the design of the urban drainage system. These design principles and associated static indicators enable a quick screening of huge number alternative solutions and provide guidance for the development and optimization of flexible urban drainage system. Within the framework for optimization of flexibility, the design principles can help identify the most promising alternative solutions for the design of urban drainage systems. The optimization framework includes the following steps: identification of the required flexibility, generation of alternative solutions for the design of urban drainage systems, screening of the most promising alternative solutions, detailed measurement of flexibility provided by the alternative solutions; and selection of optimal solution. Hence out of a sample of different design approaches, the solutions with the highest flexibility could be identified. The successful application of flexible design in three case studies illustrates that the concept provides a suitable strategy for dealing with the challenges associated with future uncertainties. For urban drainage systems, flexible design guarantees high levels of performance in uncertain future states while reducing the effort required to adapt the system to changing future conditions. This study contends that flexibility allows for profound decision making for urban drainage design despite future uncertainties.

L'essor que connaît aujourd'hui la gestion intégrée des eaux pluviales s'accompagne d'un recours croissant à des techniques favorisant l'infiltration de l'eau “à la source”, disséminées sur des bassins versants urbains. Néanmoins, de telles pratiques suscitent des interrogations sur la capacité du sol à jouer le rôle de “filtre” vis-à-vis des polluants présents dans le ruissellement. Ces travaux de thèse s'intéressent à la contamination du sol par les métaux et les hydrocarbures aromatiques polycycliques (HAP) dans ces dispositifs, avec trois objectifs : (i) évaluer les niveaux et l'étendue spatiale de la contamination, (ii) mieux comprendre les mécanismes qui gouvernent le devenir de ces contaminants dans le sol des ouvrages, et (iii) proposer des recommandations sur la conception et la maintenance de ces installations, afin de leur assurer un fonctionnement épuratoire durable.La première partie du travail consiste en une série d'investigations expérimentales sur dix sites d'étude aux caractéristiques contrastées, en service depuis plus de dix ans. Cette phase donne lieu à des cartographies de la contamination superficielle en éléments traces métalliques, puis à des profils verticaux de métaux et HAP, accompagnés de différentes variables explicatives. La distribution spatiale des métaux en surface, qui est toujours structurée autour de la zone d'arrivée de l'eau, porte la signature du fonctionnement hydraulique réel des dispositifs, et révèle le caractère non-uniforme de l'infiltration lors des événements pluvieux courants, qui représentent la plus grande partie du flux polluant à l'échelle annuelle. Dans la zone la plus contaminée des ouvrages, métaux et HAP présentent un enrichissement significatif sur 10 à 40 centimètres de profondeur. La rétention des contaminants résulte de la combinaison de processus physico-chimiques (adsorption) et mécaniques (sédimentation et filtration) ; leur importance relative peut être quantifiée grâce au déficit de zirconium dans le sédiment urbain par rapport au bruit de fond géochimique local. La variabilité inter-sites des niveaux de contamination s'explique à la fois par les capacités de rétention du sol et par les flux de polluants issus du bassin versant d'apport. Bien que les teneurs de surface excèdent, sur certains sites, les seuils internationaux de remédiation du sol pour des espaces “multifonctionnels”, la zone concernée représente — latéralement et verticalement — une région assez limitée dans les ouvrages.La seconde partie de la thèse consiste en une approche de modélisation, dont la finalité est de décrire l'évolution à long terme de la contamination du sol, et d'évaluer l'incidence de différentes pratiques de conception ou de gestion. Une analyse de sensibilité est d'abord mise en œuvre afin d'identifier les “éléments-clés” dans la description du système, et d'orienter le choix du modèle. Les résultats montrent qu'une mauvaise estimation de la dispersivité ou de l'isotherme d'adsorption du sol est susceptible de biaiser significativement la prévision des profils de contamination. Dans la suite du travail, on propose une méthode visant à décrire l'infiltration non-uniforme et la filtration des polluants particulaires. Le modèle ainsi construit est validé via une comparaison entre mesures et simulations sur l'un des sites d'étude faisant l'objet d'une nouvelle caractérisation approfondie. Enfin, une analyse de scénarios illustre les bénéfices d'un amendement de l'horizon superficiel par un matériau adsorbant, ainsi que d'une répartition homogène des flux d'eau en surface, en matière de durée de vie des installations et de fréquence d'intervention. / Sustainable Urban Drainage Systems (SUDS) are increasingly used for stormwater management. However, the generalization of runoff infiltration in urban watersheds raises some concerns regarding the soil's ability to retain ubiquitous micropollutants. The present work addresses soil contamination by trace metals and polycyclic aromatic hydrocarbons (PAHs) in such infiltration devices, with the aims of: (i) appraising the levels and spatial extent of soil contamination, (ii) better understanding the mechanisms which govern the fate of contaminants in these systems, and (iii) identifying design and maintenance guidelines which may enhance long-term pollutant control through SUDS.The first part of the study consists in a series of experimental investigations in ten contrasting study sites, which have been in operation for more than ten years. The two-stage methodology successively leads to cartographies of metal contamination in the surface soil, and vertical profiles of metal and PAH concentrations, along with different explanatory variables. The spatial distribution of trace metals in the upper horizon displays a systematic structure with respect to the inflow area, and bears the time-integrated signature of the infiltration fluxes and flow pathways at the surface. In the most contaminated zone of the facilities, a significant enrichment of metals and PAHs is detectable until 10 to 40 cm depth. Contaminant retention results from the combination of different physicochemical and mechanical processes (resp. sorption and sedimentation/filtration), the contribution of which can be assessed via the zirconium deficit in urban sediment in comparison to the soil's geochemical background. The inter-site variability of contamination levels is attributable to (i) differences in the soil's retention capacities, and (ii) differences in pollutant loads from the watershed. Although surface contents may exceed intervention thresholds for “multi-functional” spaces in several study sites, the area which would require soil remediation is laterally and vertically limited.These experimental assessments are complemented by a modelling approach, to describe the long-term evolution of soil contamination, and to evaluate the effect of various SUDS designs and maintenance operations. A sensitivity analysis is first carried out so as to identify the “key elements” in the system description: the results show that a wrong estimation of the soil's dispersivity or sorption isotherm is likely to induce significant biases in the predicted contamination profiles. A method is then proposed to describe non-uniform water infiltration fluxes, and the filtration of particle-bound contaminants. The model is validated via a comparison between measured and predicted metal profiles in one of the study sites, where a comprehensive soil characterization is undertaken. Finally, a “scenario analysis” illustrates the benefits of (i) using soil enrichment products with enhanced sorption capacities, and (ii) facilitating water spreading at the surface, in terms of “lifespan” of the devices and maintenance requirements.

The overarching goal of this research is to establish a successful forum for a transition from the existing paradigm of managing wastewater infrastructure to a more sustainable paradigm that achieves a more efficient utilisation of wastewater assets. A transitioning approach to support a more efficient utilisation of surface water and wastewater assets and infrastructure is proposed and developed. The determined transitioning approach possesses key stages namely developing the arena, developing the agenda, case study, and monitoring. The case study stage investigates a drainage utility identifying their improvement drivers, the removal of surface water through detailed drainage modelling and the financial examination of the costs incurred under the various scenarios conducted. Understanding the implications of removing/attenuating surface water from the network is improved through obtaining data by detailed drainage modelling. Infoworks software is used to investigate and assess the current and future operational scenarios of a wastewater system operating over one calendar year. Modelling scenarios were conducted removing surface water from selected areas focusing on the volumes requiring pumping and durations of pumping station(s) operation prior to treatment during storm conditions. The financial implication of removing surface water in combined sewer systems is examined in three main components. Firstly the costs of electricity incurred at the single sewage pumping station (SPS) investigated during the various scenarios modelled require to be addressed. Secondly the costs to retrofit sustainable urban drainage system (SUDS) solutions needs to be identified. Thirdly the implications of removing surface water for the drainage utility at the national level and the potential saving for householder’s committing to a surface water disconnection rebate scheme. When addressed at the macro level i.e., with over 2,100 pumping stations, some operating in sequence and contained within one drainage utility annually treating 315,360 megalitres the significance of the same multiple quantifiable and intangible benefits becomes amplified. The research aims, objectives and findings are presented to the identified and convened stakeholders. The transitioning approach developed encourages positive discourse between stakeholders. The level of success of the transitioning approach determined is then tested using a quantitative methodology through the completion of questionnaires. From the questionnaires completed the respondents unanimously agreed that surface water flows should be removed as well as reduced from the combined sewer system. The respondents agreed that the removal of surface water from a typical combined sewer system is justified by applying a transitioning approach focusing on the energy consumption required to pump increased volumes during storm events. This response is significant based upon the economic evidence and is contrary to the respondents previous position that finance was their most influencing factor. When provided with other potentially available benefits the respondents were even more supportive of the justification to remove surface water from the combined sewer system. The combined findings of the work presented in this thesis provide further justification that the transitioning approach applied to the removal of surface water from a typical combined sewer system, as determined in this research has been successful.

Our planet stands before many great challenges, where climate change and urbanization are two of the major challenges. One of the challenges due to climate change is the increased amount of precipitation and of extreme rainfall, which creates a higher amount of stormwater within the urban areas and an increased risk of urban flooding. Urbanization and an increasing global population put pressure on the environment as more land is exploited and existing urban areas are further developed and densified. Urban areas are already under high pressure to handle the risks of climate change, therefore is climate change adaptation prominent to create more resilient and sustainable urban areas, where stormwater management is one of the challenges that need to be tackled. The aim of this study is to answers one main research question and three sub research question about enablers, barriers, and key factors regarding planning, designing, and implementing sustainable urban drainage systems in the built environment. The used methods are literature study research and multiple case study research. Five case study areas where studied to gather knowledge about areas that have implemented sustainable urban drainage systems. Lessons learned for each of the case study areas where gathered and connected to the literature and used to answer the research questions. The gathered knowledge from the literature and case studies where used to compile recommendations of how a sustainable urban drainage system could be planned and implemented at a pilot study area, which is Välsviken in Karlstad, Sweden. To be able to achieve a sustainable and resilient urban drainage system, that can handle the challenges of climate change and urbanization, it is important that the stormwater planning process is changing. It is crucial to implement facilities and systems that are sustainable, multifunctional, and flexible. The planning process needs to use planning and costing approaches that include flood mitigation and co-benefits, in the long-term and short-term simultaneously. Implementation of sustainable urban drainage systems also needs to be enabled in new areas or being retrofitted into already exploited areas. This could make it possible to create urban areas that are able to tackle the challenges of climate change and urbanization, and create multifunctional, sustainable, and flood mitigated urban areas. / Vår planet står inför många stora utmaningar, där klimatförändringar och urbanisering är två av dessa. En av utmaningarna med avseende på klimatförändringarna är den ökade mängden av nederbörd och extrema regntillfällen, vilka bidrar till större mängder dagvatten i urbana områden och en ökad risk för översvämningar. Urbaniseringen och det ökande antalet invånare globalt sätter press på miljön eftersom mer landyta exploateras och nuvarande urbana områden fortsätter att bebyggas och förtätas. De urbana områdena har redan stora utmaningar med att hantera riskerna med klimatförändringarna. Klimatanpassning är därför viktigt för att skapa mer resilienta och hållbara urbana områden, där dagvattenhanteringen är en av utmaningarna som behöver hanteras. Målet med denna studie är att besvara en övergripande forskningsfråga och tre underliggande forskningsfrågor om möjliggörare, barriärer och nyckelfaktorer gällande planering, design och implementering av hållbara urbana dagvattensystem i den bebyggda miljön.  Metoderna som användes var litteraturstudie och multipel fallstudie. Arbetet började med litteraturstudien och sedan genomfördes en fallstudie där fem områden som implementerat hållbara urbana dagvattensystem undersöktes. Lärdomar från varje område sammanställdes och kopplades samman med den andra litteraturen för att besvara forskningsfrågorna.  Utifrån litteraturen och fallstudierna sammanställdes rekommendationer för hur ett hållbart urbant dagvattensystem kan planeras och implementeras inom ett utvalt studieområde, vilket är Välsviken i Karlstad, Sverige.   För att åstadkomma ett hållbart och resilient urbant dagvattensystem, som kan hantera utmaningarna gällande klimatförändringar och urbanisering, är det viktigt att planeringsprocessen för dagvatten ändras. Det är viktigt att implementera anläggningar och system som är hållbara, multifunktionella och flexibla. Planeringsprocessen behöver använda planerings- och kostandsmetoder som inkluderar översvämningsanpassning och sidofördelar, både långsiktigt och kortsiktigt samtidigt. Man behöver också möjliggöra implementering av hållbara urbana dagvattensystem i nya områden eller anpassa områden som redan är bebyggda. Detta kan bidra till att skapa urbana områden som kan hantera klimatförändringarnas och urbaniseringens utmaningar, och skapa multifunktionella, hållbara och översvämningssäkrade områden.

Over the past decades, the fast-changing global climate poses a significant challenge to many cities around the world to embrace resilience concepts, whereby a safe-to-fail planning approach replaces traditional fail-safe practices. The change in perspectives has seen an increase in climate-adapted infrastructural projects being integrated with the new urban planning agendas across the world. The investigation conducted was designed to understand the process of how resilience concepts travel between different cities, by investigating the actors who move policy knowledge, their roles in it, as well as the knowledge transfer process mechanism that is responsible for the movement of such policies. The investigation took advantage of a scoping study technique to answer the research questions, using mostly secondary data and an interview to verify the secondary sources. The findings and the discussion provided insights on who is involved in resilience policies and how these policies are transferred from one place to another. The investigation uncovered the influence policy mobilizers has on the movement of policy knowledge, as well as how the mobilization of policy knowledge can both be beneficial or detrimental, depending on the way it was moved or implemented. / Under de senaste decennierna utgör det snabba föränderliga globala klimatet en betydande utmaning för många städer runt om i världen med att anamma motståndskraftskoncept, där en planeringsstrategi med säkerhet att misslyckas ersätter traditionella felsäkra metoder. Förändringen i perspektiv har ökat klimatanpassade infrastrukturprojekten som integrerats med nya stadsplaneringsagendorna över hela världen. Studien genomfördes för att få en förståelse av hur motståndskraftskonceptet färdas mellan olika städer och detta genomfördes genom att undersöka de aktörer som förflyttar politisk kunskap och deras roller i den samt den kunskapsöverföringsmekanism som är ansvarig för rörelsen av sådan politik. Studien utnyttjade en scoping-studieteknik för att få svar på forskningsfrågorna, med mestadels sekundär data och en intervju för att verifiera sekundärkällorna. Resultaten och diskussionen gav insikter om vem som är inblandad i motståndskraft och hur policy överförs från en plats till en annan. Studien avslöjade även inflytande av politiskt mobilisering och kunskap som både kan vara fördelaktig eller skadlig beroende på hur den flyttades eller genomfördes.

One of the main challenges in promoting rainwater management into practise is the fact that it was not recognized as an interdisciplinary issue. We should seek ways how to open the problem to other professions, specially for architects and urban planners, who are the key element of its farther development. This work analyzes the reasons of this unsatisfactory state of rainwater management in the Czech Republic and it defines the possible ways how to remedy this state and outlines scenarios of its further development. The default document of the work is czech technical standard "TNV 75 9010 Hospodaření se srážkovými vodami". The new methodological guide, which is part of this work, is based on it. The work extends the range of measures which are mentioned in the standard. It brings new ways for assessing the benefits of the various measures to streamline the application of rainwater management measures in urban space.