Syfte: I dagens läge byggs nya dagvattendammar för att magasinera dagvatten som överbelastar dagvattenledningssystemen och de befintliga dagvattendammarna förblir utan översyn. Eftersom klimatförändringar bidrar till att femårsregn kommer i en högre frekvens ökar flödet av dagvatten och orsakar att allt fler dagvattendammar kommer att bli underdimensionerade. För att bevara samhällsfunktioner utreds en generell arbetsprocess hur kommuner kan undersöka och bevara befintliga dagvattendammar. Metod: Metoderna som används är intervju, fallstudie och litteraturstudie. Intervju bidrar till att lösningar och förslag av undersökningsmetoder och åtgärdsförslag samlas in. Fallstudien utfördes på tre olika dagvattendammar och undersöker vilka undersökningsmetoder som kan användas. Att samla empiri i ett praktiskt fall bör bidra till att utredningens trovärdighet förstärks. De metoderna som användes i fallstudien är beräkningar, sedimentprovtagning och dokumentanalys från underlag av befintliga dagvattendammar. Med hjälp av litteraturstudie analyseras utredningens empiri med andra källor för att kontrollera empirins tillförlitlighet. Resultat: Ett flertal undersökningsmetoder och åtgärdsförslag analyserades. Tre undersökningsmetoder som passade en generell arbetsprocess var: flödesproportionell provtagning, sedimentprovtagning och dagvattenberäkningar med dagvattenmodellen Stormtac. Åtgärdsförslag som passade var: byggnation av en vall runt dammen för att utöka magasineringen, plantering av växter som tar upp näringsämnen och tungmetaller bundna i dagvattnet, utnyttja dagvattendammens form där dagvattendammens hydrauliska effektivitet utnyttjas maximalt samt anlägga fördamm med en makadamvall med vattenlevande växter. Konsekvenser: Flödesproportionell provtagning var tillförlitlig undersökningsmetod enligt intervju och litteraturstudie. Sedimentprovtagning av sediment i botten av inoch utlopp går att nyttjas i en generell arbetsprocess, men vissa föroreningshalter kan vara missvisande beroende på hur detaljerat sedimentprovtagningen görs. Dagvattenmodellen Stormtac och dess beräkningar kan nyttjas i en generell arbetsprocess eftersom Svenskt Vatten P110 (2016) bekräftar modellens beräkningar. Åtgärdsförslagen testades inte i verkliga fall, men effekten bekräftades i intervjun och litteraturstudien. Ett förslag på generell arbetsprocess kunde sammanställas. Stickprovstagning passar sämre in i en generell arbetsprocess. Begränsningar: Fallstudien har begränsats genom att utreda två metoder, varav den ena är dagvattenmodellen Stormtac och den andra är sedimentprovtagning. Utvalda föroreningar som tungmetaller, olja, kväve och fosfor analyseras. Studien avgränsas från att analysera hur recipienter påverkas av de befintliga dagvattendammar som studerats. / Purpose: At present are new stormwater ponds constructed to store stormwater which overloads stormwater pipe systems while existing stormwater ponds remains without overhaul. Since climate changes contributes to five-year rain in a higher frequency, which increases the flow of stormwater and causing more stormwater ponds to be undersized. In order to preserve social functions, are a general work process investigated of how municipalities can investigate and preserve their existing stormwater ponds. Method: The methods that are used are interviews, case study and literature study. The interviews contribute to solutions and proposals of investigation methods and proposals for action. The case study were performed in three stormwater ponds and examines the investigation methods that can be used. Collecting empirical data in a practical case, should increase the investigation’s credibility. The methods used in the case study are calculations, sediment sampling and document analysis of the basis of existing stormwater. Using literature study are the empirical data of the investigation analyzed with other sources to check the reliability of the empirical data. Findings: Several methods of investigations and action proposals were analyzed. Three investigation methods which fit a general work process were: flow proportional sampling, sediment sampling and stormwater calculations through the stormwater model Stormtac. The proposals for action which suited a general work process were: construction of a trench around the pond to expand the storage area, planting plants that take up nutrients and heavy metals tied up in stormwater, exploit the stormwater ponds shape where the hydraulic efficiency are exploited flat out by placing the inlet and outlet on opposite ends, and building trenches with a gravel embankment with aquatic plants. Implications: Flow proportional sampling were a reliable investigation method according to interview and literature study. Sediment sampling of sediment in bottom of in- and outlet can be used in a general work process, but certain contamination levels can be misleading depending on how detailed sediment samplings are done. Stormwater model Stormtac and its calculations can be used in a general workprocess because publication Svenskt Vatten P110 (2016) are confirming the models calculations. The proposals for action were not tested in real cases, but the effect was confirmed in the interview and literature study. Limitations: The case study was limited by investigating two methods, one of which is stormwater model Stormtac and sediment sampling. Selected contaminants such as heavy metals, oil, nitrogen and phosphorus are analysed. The study is delimitated by analyzing how recipients are affected by the studied existing stormwater ponds.

Stormwater runoff from urban and urbanizing areas poses a serious threat to water quality, and unless managed properly will impede efforts to restore the Chesapeake Bay.Water quantity, as well as quality, must be considered, and Low Impact Development(LID) is an innovative stormwater management approach that addresses both. LID seeks to mimic a site's predevelopment hydrologic regime by retaining and treating stormwater at the lot level using small, cost-effective landscape features.The purpose for this study was to identify and rank impediments to the implementation of LID in the Virginia portion of the Chesapeake Bay watershed. This was accomplished by going to LID workshops and distributing a survey to stakeholders in attendance. The survey asked respondents to rank the following impediments to the implementation of LID: site-specific & non-structural, property owner acceptance, pollutant removal benefit, development rules, lack of education, maintenance considerations, flooding problems, and cost. Lack of education was ranked as the most important impediment, with development rules following close behind. Pollutant removal benefit was ranked the least important impediment. A second purpose was to assess whether there is a relationship between a county's growth rate and adoption of Better Site Design principles (BSD) and LID. A Code and Ordinance Worksheet was used to evaluate the development rules of 13 counties (6 high growth, 3 medium growth and 4 low growth) within Virginia's portion of the Chesapeake Bay Watershed. The scores from the worksheets were used to determine if the amount of growth pressure experienced by a county influenced the degree to which they incorporated BSD and LID in their local development codes. Statistical testing revealed that the relationship between growth pressure and score on the Code and Ordinance Worksheet was moderate, at best.

Syfte: Fokus på dagvattenhantering är viktigt eftersom översvämnings- och föroreningsrisker blir allt mer förekommande på grund av klimatförändringar och urbanisering med en ökad andel hårdgjorda ytor. Vid exploatering vill kommuner utnyttja befintliga diken istället för att bygga nya ledningssystem, därmed kan de behöva samverka med markavvattningsföretag. Syftet med studien är att underlätta samarbetet mellan markavvattningsföretag och kommuner för att undvika översvämningar och föroreningar som förändring av stad och klimat kan medföra. Målet är att identifiera faktorer som kan förbättra samverkan mellan markavvattnings-företag och kommuner. Metod: Studien utgår ifrån en fallstudie som består av kommuner som har samverkat med markavvattningsföretag. De datainsamlingsmetoder som använts för att besvara frågeställningarna är litteraturstudier och semistrukturerade intervjuer med kommuner som har erfarenhet av sådana samverkansprocesser; Linköping och Norrköping. Resultat: De faktorer som kan förbättra samverkan är framförallt kommunikationen mellan parterna för att finna ömsesidiga nyttor och att uppdatera registren över markavvattningsföretag. Fallstudien har visat att förbättring av samverkan kan uppnås genom rådgivningsstöd från en transparent aktör. Norrköpings kommun önskar bland annat en enkel handbok som är framtagen av någon myndighet för att få det transparent och som är anpassad för aktörer med mindre kännedom kring processen. Fallstudien har även påvisat att markavvattningsföretag är en intressent som har hög angelägenhet att påverka projekt samtidigt som de har makt att styra projektets tidsaspekt. Dessa är projektets nyckelintressenter som är viktiga aktörer för projektets helhet och som måste prioriteras, hållas informerade och nöjda för att underlätta samverkan. För att upprätthålla en hållbar stadsutveckling behöver översvämnings- och föroreningsrisker minskas för att skydda naturresurser och bevara den biologiska mångfalden. Öppna diken mildrar belastningen på avloppssystemen som i sin tur minskar risker för översvämningar och främjar biologisk mångfald. Konsekvenser: Kännedom om betydelse av användandet av öppna diken är nödvändigt för att upprätthålla hållbar stadsutveckling. Det saknas uppgifter i registren över markavvattningsföretag eftersom de inte är uppdaterade. Det kan därmed bli ett detektivarbete för kommuner att komma fram till rätt person. Denna problematik medför även att en del markavvattningsföretag saknar kännedom om dess roll i projekten. Det finns dessutom ingen myndighet att rådfråga i dessa samverkansprojekt. Begränsningar: Det var endast kommuner med erfarenheter av dessa projekt som inkluderades i undersökningen eftersom frågeställningarna krävde viss kännedom om markavvattningsföretag. Det var även lämpligt att endast ta hänsyn till faktorer som berör samverkansprocessen, utan att studera övriga påverkande aspekter såsom jordens permeabilitet eller växters vattenupptag eftersom detta inte påverkar studiens utfall. / Purpose: Focus on stormwater management is important because water pollution and flood risks are increasingly anticipated effects of climate change and urbanization. In case of urban growth areas, municipalities want to exploit the existing ditches rather than install new pipes. Here cooperation with agricultural drainage organizations may be required. This study contains exposition of key factors to facilitate such cooperation’s to support sustainable urban development. The purpose of this study is to facilitate the cooperation between agricultural drainage organizations and municipalities in order to avoid flooding and pollution which urbanization and climate change can result in. The objective is to identify factors that can help improve cooperation between agricultural drainage organizations and municipalities. Method: The study was carried out as a case study of municipal cooperation with agricultural drainage organizations. Data was collected from literature studies and semi-structured interviews with municipalities with previous such experiences; Linköping and Norrköping. Findings: The factors that can improve cooperation are foremost communication between both parties in order to find mutual benefits and to keep the registers over agricultural drainage organizations updated. This case study has shown that improvement of collaboration can be achieved through counseling support from a transparent actor. Norrköping Municipality wishes for a simple handbook accessible even to actors with little to no prior knowledge about the process. The case study has also shown that agricultural drainage organizations are stakeholders who have a high interest in influencing projects while also having the power to control the project's time aspect. These are the key stakeholders of the project, who are important players for the project as a whole and who must be prioritized, kept informed and satisfied to facilitate collaboration. To maintain sustainable urban development the risks of flooding and water pollution need to be minimized to protect biodiversity. Open ditches mitigate the load on drainage systems which reduces the risk of flooding and support biodiversity. Implications: Knowledge of the importance in using open ditches is necessary to maintain sustainable urban development. There is data missing in the registers over agricultural drainage organizations since they are not updated. This results in difficulties for municipalities when trying to reach the correct person. This problem also results in some agricultural drainage organizations missing knowledge of their part in projects. There is also no authority to consult in these cooperative projects. Limitations: The study does not consider other aspects beside the cooperation between municipalities and agricultural drainage organizations. Only municipalities with prior experience of working with agricultural drainage organizations were questioned as the questions required certain knowledge about these processes. It was also appropriate to only consider factors that affect the cooperative process without studying other affecting aspects like the permeability or water uptake of plants since this does not affect the results of the study.

Urbanization and increase of impervious areas impact stormwater runoff and can pollute receiving waters. Total suspended solids (TSS) are of particular concern as they can act as a transport agent for other pollutants. Moreover, the existence of the first flush phenomenon (FF), whereby the first stage of storm runoff is the most concentrated, can also have profound ecological effects on receiving waters. Understanding the various types of pollutants in watershed stormwater, their correlation with rainfall parameters (precipitation depth and previous dry days) and with TSS, and the existence of FF is crucial to the design of the most suitable structural best management practice (BMP) that can mitigate their harm. Personal Computer Storm Water Management Model (PCSWMM) is a well-known computer model that can simulate urban runoff quantity and quality and model BMPs. The use of PCSWMM to simulate the first flush phenomenon and to evaluate the effectiveness of structural BMPs has not been previously investigated for a large urban watershed with seriously polluted stormwater runoff. This research is concerned with the study of a framework for designing structural best management practices (BMPs) for stormwater management in a large watershed that is based on comprehensive analysis of pollutants of concern, rainfall parameters of influence, and the existence of FF. The framework was examined using the PCSWMM computer model in the St Anthony Park watershed, an urban watershed in St Paul, Minnesota with a large drainage area of 3,418 acres that discharges directly into the Mississippi River via a storm tunnel. A comprehensive study was undertaken to characterize the overall St. Anthony Park watershed stormwater quality trends for the period of record 2005-2013 for heavy metals, nutrients (ammonia and total phosphorus), sediment (TSS), and bacteria (E. coli). Stormwater was found to be highly contaminated as measured by exceedance of the Minnesota Pollution Control Agency (MPCA) water quality standards and as compared to data obtained from the National Stormwater Quality Database (NSQD). None of the examined parameters significantly correlated with precipitation depth. Concentrations of most heavy metals, total phosphorus and TSS positively correlated with previous dry days, and most pollutants correlated positively with TSS, which provided a strong rationale for using TSS as a representative pollutant in PCSWMM and in examining BMP efficiency. Moreover, BMPs that targeted the particulate fraction in stormwater would be the most efficient in reducing stormwater pollution. A PCSWMM model was built based on the existing drainage system of the watershed, which consisted of inlet structures, manholes, pipes and deep manholes that connect the network pipes to a deep drainage tunnel discharging directly into Mississippi River. The model was calibrated and validated using recorded storm and runoff data. FF was numerically investigated by simulating pollutant generation and washoff. Using three different numerical definitions of FF, the existence of FF could be simulated, and was subsequently reduced by simulating extended dry detention ponds in the watershed. Extended dry detention ponds (EDDPs) are basins whose outlets are designed to detain stormwater runoff for a calculated time that allows particles and associated pollutants to settle. Extended dry detention ponds are a potential BMP option that could efficiently control both water quantity (by diverting initial volumes of stormwater, thus addressing FF) and quality (by reducing suspending pollutants, thus addressing TSS and co-contaminants). Moreover, they are the least-expensive stormwater treatment practice on a cost per treated unit area. Two location-based designs were examined. The first was an EDDP at the main outfall (OFmain), while the second was a set of seven smaller EDDPs within the vicinity of deeper manholes of the deep tunnel (distributed EDDPs). Distributed EDDPs were similar to the OFmain EDDP at reducing peak stormwater flow (52-61%) but superior in reducing TSS loads (20-25% for small particles and 43-45% for larger particles based on the particle sedimentation rate removal constant k) and in reducing peak TSS loads (67-75%). These efficiencies were obtained using the dynamic and kinematic wave routing methods, indicating that they could be used interchangeably for this watershed. The steady state routing method produced unrealistic results and was subsequently excluded from FF analysis. Finally, distributed EDDPs were superior to OFmain EDDP at eliminating FF per the stringent fifth definition (Δ > 0.2). This was true for small values of k. However, larger values of k and other FF tests (above the 45º no-flush line and FF coefficient b < 1) showed that BMP implementation overall failed to completely eliminate FF. This suggested that the extended time required by EDDPs to efficiently remove pollutants from stormwater via settling would compromise their ability to completely eliminate FF. In conclusion, a comprehensive framework was applied so as to better design the most efficient BMPs by characterizing the overall St. Anthony Park watershed stormwater pollutants, their correlation with rainfall parameters and with TSS, and the magnitude of FF. A cost-effective, rapid, and accurate method to simulate FF and study the optimal BMP design was thus implemented for a large urban watershed through the PCSWMM model.

The impervious surfaces of built landscapes create stormwater runoff that causes water quantity and quality problems downstream, upsetting natural hydrology and harming aquatic ecosystems. Green stormwater infrastructure (GSI) includes practices that reduce the amount of stormwater runoff and the pollutants it carries utilizing plants, soils, and other materials to capture, store, reuse, infiltrate, evapotranspire, and filter stormwater. GSI helps to restore developed landscapes, mimicking natural hydrologic processes and providing important water treatment functions as well as beneficial green spaces in urban areas. However, there are many challenges associated with the implementation and maintenance of GSI in our communities and cultures. This research explores the human side of implementing GSI, investigating current maintenance capacities in rural and urban settings, and exploring multifunctional benefits of GSI to provide both biophysical and cultural ecosystem services (CES). Research goals include characterizing the current state of GSI implementation and maintenance in municipalities in the State of Vermont (USA) and eliciting lessons that can inform GSI design practices and policies. Multifunctional GSI design objectives that provide and enhance CES are described, revealing opportunities to instill values and a sense of stewardship for the health wellbeing of people and ecosystems. The first chapter provides relevant topical background to set the stage for the latter two chapters. The second chapter analyzes results from a survey of municipal officials in Vermont that occurred as part of NSF-EPSCoR-funded Basin Resilience to Extreme Events project research on stormwater management. The survey included questions about GSI and maintenance practices in place and perceptions of visual appeal and ability to maintain bioretention systems shown in landscape visualizations. Results show that visual appeal and perceived maintainability of vegetated bioretention practices do not appear to be significant barriers to adoption and operation, but stormwater policy and funding are shown to be both significant barriers and solutions to implementing and maintaining GSI in Vermont municipalities. Additionally, urban and rural towns provide very different contexts for implementing and maintaining GSI in Vermont and characteristics of development patterns and maintenance capacity should be considered in policy, regulations, outreach, and education. The third chapter offers a literature review, guided by a CES framework, of design elements that can be included in GSI to create multifunctional urban green spaces. CES categories of aesthetic, recreation, education, sense of place, social capital, and stewardship benefits framed a set of design elements, principles, practices, and documented benefits to guide multifunctional design of GSI. Findings include the importance of participatory processes to elicit diverse landscape values, visible water pathways, biodiversity, spaces for creative use, accessibility, interaction with water, interpretive signage, and artful and biophilic design features to enhance feelings of preference, pleasure, relaxation, learning, connection, and inclusion. The health and wellbeing of water and people must be integrated into the design of GSI for cities to be ecologically functional and culturally meaningful to their populations.

The Green Space Based Learning (GSBL) approach builds on a long-term partnership between a Research I university, surrounding community, and local school district, transforming underutilized community green space into an interactive educational tool to addresses national infrastructure and educational challenges. The GSBL approach is an educational platform for engaging K-12 and the local community in engineering design and construction of sustainable Green Infrastructure (GI) projects. GSBL was piloted as a part of a federally funded Research Experience for Teachers (RET) program in which teachers participated in two intensive 6-week summer research experiences and two consecutive academic year components. The summer experience focuses on the development of Science Technology Engineering and Mathematic (STEM) lessons and activities that meet Common Core and Next Generation Science Standards and the dissemination of the RET research experience. Approximately 400 K-12 students and teachers participated in both formal and informal educational activities that led to GSBL approach outputs throughout the academic year. These outputs included 4 Campus GI Challenge's for identifying areas of implementation and student driven GI design, the publication of 7 curricular products, the design and installation of 70 personal rain gardens and 8 bioretention cells (a type of GI), one of which was designed as a field scale research site within the Hillsborough County Public Schools (HCPS) district. The eight bioretention cells, seven of which are on three public school campuses and one located at a local community leader's house were designed and implemented as a result of university research, K-12 outreach, and community engagement. These sites were selected based on one or more hotspot factors (e.g. localized areas of flooding, access to site, presence of learning space, willingness to pay, property ownership, visibility of location) and designed to restore the hydrology and water quality to pre-development conditions. The bioretention cells were designed to capture a storm-event ranging from 1.27 cm to 2.54 cm and cost between $550 and $1,650 to construct depending on the design scope, scale, and installation methods. The installed bioretention systems route stormwater runoff to a ponding area sized approximately 2-5% of the total catchment area, are designed to capture between 31% and 67% of annual runoff (March 2010 - March 2015), and attenuate between 97,500 and 226,100 mg N annually. The educational sites were used to provide insight into hydraulic performance, maintenance requirements, and nutrient management impacts associated with bioretention design. Three of the bioretention cells (BR 1, BR 2, and BR 3) were used as a field research site for collecting bioretention plant performance data on 12 Florida native plant species, Coreopsis leavenworthii, Flaveria linearis, Salvia coccinea, Solidago fistulosa, Canna flaccida, Tradescantia ohiensis, Tripsacum dactyloides, Hymenocallis latifolia, Iris virginica, Sisyrinchium angustifolium, Spartina patens, and Equisetum hyemale. Mean baseline accumulated nitrogen concentration for tested species was 18.24 ± 5.76 mg N/g biomass. This compared to a harvested mean concentration rate of 12.28 ± 2.23 mg N/g biomass, a reduction of uptake capacity of nearly 33% after two growing seasons. This study found a similarity in mean total nitrogen concentration between baseline and harvested plant species for Flaveria linearis, Sisyrinchium angustifolium, Solidago fistulosa, Canna flaccida, Salvia coccinea, Spartina patens, and Coreopsis leavenworthii and a significant difference in means for Equisetum hyemale, Iris virginica, Salvia coccinea, and Tradescantia ohiensis. These harvested data were used to calculate mean total nitrogen concentration per square meter with Sisyrinchium angustifolium, Equisetum hyemale, Spartina patens, Solidago fistulosa, Salvia coccinea, Coreopsis leavenworthii, Iris virginica ranging from 286 mg N/m2 to 4,539 mg N/m2, and Canna flaccida, Flaveria linearis, Tradescantia ohiensis ranging from 12,428 mg N/m2 to 15,409 mg N/m2. Seven of the twelve species (Flaveria linearis, Equisetum hyemale, Iris virginica, Tripsacum dactyloides, Coreopsis leavenworthii, Salvia coccinea, Tradescantia ohiensis) displayed highly desirable results, ranking (>0.20x̅) when evaluated across 10 quantitative attributes and assessed for their applicability for the subtropical Tampa Bay area. This research developed a plant selection utility index (PSI) that allows for individual plant scoring based on qualitative and quantitative plant selection criteria. The qualitative PSI was used to evaluate 26 native and regionally friendly plant species commonly found within the subtropical Tampa Bay climate to provide an example and act as a template for selecting plant species. The qualitative PSI scores categorized the identified plant species as highly desirable (n=4, PSI ≥ 80), Flaveria linearis, Tripsacum dactyloides, Salvia coccinea, and Chamaecrista fasciculata; moderately desirable (n=15, 80 > PSI ≥65), Solidago fistulosa, Hymenocallis latifolia, Canna flaccida, Tradescantia ohiensis, Arachis glabrata, Mimosa strigillosa, Callicarpa Americana, Penta lanceolata, Monarda punctate, Muhlenbergia capillaris, Helianthus debilis, Glandularia tampensis, Silphium asteriscus, Stachytarpheta jamaicensis, and Coreopsis lanceolata; and least desirable (n=7, PSI < 65) Spartina patens, Equisetum hyemale, Sisyrinchium angustifolium, Iris virginica, Coreopsis leavenworthii, Myrcianthus fragrans, Zamia puila. The quantitative PSI was used to evaluate attributes of 11 of the 26 species within a 32.5 m2 field-scale bioretention system (BR 1, BR 2, and BR 3) ter two-growing seasons. The tested species scored as highly desirable (n=2, PSI ≥ 70) for Salvia coccinea, Tradescantia ohiensis; moderately desirable (n=5, 70 > PSI ≥ 50) for Equisetum hyemale, Sisyrinchium angustifolium, Solidago fistulosa, Iris virginica, Coreopsis leavenworthii, and least desirable (n=4, PSI < 50) for Spartina patens, Flaveria linearis, Canna flaccida, Hymenocallis latifolia. Both qualitative and quantitative scores were combined on a 0-200 scale to provide a list of recommended species based, ranking from high to low: Salvia coccinea (PSI=160), Tradescantia ohiensis (PSI = 148), Sisyrinchium angustifolium (PSI =127), Flaveria linearis (PSI = 125), Solidago fistulosa (PSI = 124), Iris virginica (PSI =121), Coreopsis leavenworthii (PSI = 117), Equisetum hyemale (PSI = 114), Canna flaccida (PSI = 104), Spartina patens (PSI = 103), Hymenocallis latifolia (PSI =90).

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.

There are several aspects which need to be considered while planning a building to achieve sustainable environment for people's well-being. One of the significant aspects is social sustainability which is largely about promoting everyone regardless of the circumstances. In a socially sustainable city, there should be access to meeting places to improve social life. The Park Paradiset and the Broparken in Vallastaden were designed to improve socializing between people. The parks in this work are examined based on social aspects; interaction and identity. In addition, a park should be designed based on different aspects to suit different people. This work considers aspects such as recreation/ leisure, cultural identity, accessibility and safety. Beyond these aspects, the stormwater management in the parks is also studied. These studies were conducted with systematic literature studies, site visits, survey and qualitative interviews. A site visit was in Vallastaden, where the authors explored the district and handed out survey to the resident. The interview for the Park Paradise was conducted with Ulrika Gunnman from White Arkitekter and the interview for the Broparken was conducted with Lina Moström from 02landskap. The result shows that the architects worked differently to achieve the social aspects. It can be concluded that Park Paradiset fulfills the aspects better than the Broparken based on survey results, site visits and the interviews. The results further show that the stormwater management for the parks consists of open systems. Open systems have even been current in the Park Paradiset. The open ditches in the park leads the water in the transverse dikes to a longitudinal dike. It can be concluded that the architects utilized stormwater management better in Broparken compared to the Park Paradiset, when the architects transformed the ordinary ditch into something attractive and gave the park a character.

The research programme was relevant to urban planning and in particular to the design of stormwater management schemes that are more environmentally and socially acceptable. It examined social and perception issues relating to stormwater management techniques within residential areas, and in particular to the application of SUDS, mainly ponds, and river management schemes. The thesis arose from a project funded by the Environment Agency of England and Wales through SNIFFER under a programme titled “Social impacts o f stormwater management techniques including river management and SUDS”, SNIFFER Code: SUDS01. The public perception of construction is becoming a matter of increasing importance both in the UK and internationally since socio-economic parameters and public consultation both have to be taken into consideration in the planning and implementation of relevant projects. This research programme endeavoured to match the relevant legislative goals with society’s actual needs. The main aims of the research programme were to obtain an in-depth understanding and knowledge of the perceptions of popular stormwater management practices (SUDS and river management), and to evaluate these techniques from a social perspective. To satisfy these aims the following objectives were set: • To assess public awareness and perceptions of SUDS (particularly retention ponds) in the UK; • To assess professional perceptions of SUDS in the UK; • To assess perceptions of different stormwater management techniques, in three European cities; • To compare perceptions of different stormwater management techniques, SUDS and river management practices; • To link the research findings with trends in perceptions of nature and water. To meet the programme’s aims and to satisfy the objectives, the perceptions of SUDS in the UK (principally ponds) were investigated over a wide range of locations. In addition, the different river management approaches used in three heavily urbanised European cities, Glasgow, London, and Athens were investigated. The results of this research programme provide a means to understand perceptions of stormwater management and to appreciate what types of schemes will be more readily accepted by the public. The research has shown that members of the public hold strong views as to what they like or dislike about SUDS and water management installations in their local area, in spite of the fact that there were demonstrably low levels of public awareness of SUDS. The amenity, recreational value and aesthetics of new schemes seem to be of major importance for public acceptability, while function, efficiency, and maintenance are primarily important in areas facing flooding problems. Other key findings include the fact that there is a general preference for sustainable urban water management and for river restoration schemes compared with more conventional, ‘hard engineering’ approaches, such as culverting of rivers. This preference was expressed both by members of the public and by professionals involved in their planning and implementation. Another important result was that although unfamiliarity can produce negativity, education can influence attitudes positively even in sensitive issues such as safety, and can be used by authorities and planners as a means of enhancing the acceptability of new schemes. Consequently, the results of the surveys can be used as arguments towards the application of informative campaigns which should be taken into account prior to scheme implementation. This information can be utilised not only for stormwater management design, but also for other environmentally friendly constructions which the public may have a low level of awareness. Recommendations are made with respect to public and professional attitudes for improving the public acceptability of new and modified stormwater management systems. Recommendations and barriers to the uptake outlined in this thesis mainly refer to the appearance of schemes rather than technical issues. They are therefore of most use as guidance for improving aesthetics and increasing public acceptability. The outcomes of this research will be of use to policy makers, water companies, local authorities, environment agencies, planners, developers, consultants active in urban development, and researchers in applying wider-accepted practices for the assessment of public perception. Some findings from this research have been presented at several stakeholders’ meetings, at 4 conferences, and are published in the form of papers and reports, including the DTI SR 622 report titled “An Assessment of the Social Impacts of Sustainable Drainage Systems in the UK”, and the Environment Agency & SNIFFER report, SUDS01, 2005, titled “Social Impacts of stormwater management techniques including river management and SUDS”. This publication also constitutes Environment Agency R&D Technical report P2-258.

abstract: Vegetative filter strips (VFS) are an effective methodology used for storm water management particularly for large urban parking lots. An optimization model for the design of vegetative filter strips that minimizes the amount of land required for stormwater management using the VFS is developed in this study. The resulting optimization model is based upon the kinematic wave equation for overland sheet flow along with equations defining the cumulative infiltration and infiltration rate. In addition to the stormwater management function, Vegetative filter strips (VFS) are effective mechanisms for control of sediment flow and soil erosion from agricultural and urban lands. Erosion is a major problem associated with areas subjected to high runoffs or steep slopes across the globe. In order to effect economy in the design of grass filter strips as a mechanism for sediment control & stormwater management, an optimization model is required that minimizes the land requirements for the VFS. The optimization model presented in this study includes an intricate system of equations including the equations defining the sheet flow on the paved and grassed area combined with the equations defining the sediment transport over the vegetative filter strip using a non-linear programming optimization model. In this study, the optimization model has been applied using a sensitivity analysis of parameters such as different soil types, rainfall characteristics etc., performed to validate the model / Dissertation/Thesis / Masters Thesis Civil and Environmental Engineering 2015