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Stormwater runoff is a major environmental concern, particularly in urban environments. Trends in managing stormwater have evolved (and continue to evolve) from a quantity only approach into a sustainable approach, which integrates quantity, quality, the environment, and aesthetics. Best management practices (BMPs) and Low Impact Development (LID) are two well-documented techniques capable of managing to sustainable standards. There are a number of stormwater models available to design professionals today. However, there are few which integrate site-scale BMP/LID analysis in a simplified fashion. The purpose of this study is to determine if there is a demand in the design profession for simplified stormwater modeling tools to help designers make informed decisions about integrating BMP/LID strategies into site plans. A Web-based questionnaire was administered to a group of design professionals to determine their knowledge of BMPs and their technological needs and preferences in meeting stormwater goals and requirements.

Green roofs are increasingly being used in the United States to mitigate the negative effects of impervious surfaces on aquatic ecosystems. Though performance of these systems varies with climate, little research has been conducted in the Southeastern U.S., and no prior research has been conducted in Mississippi. An experiment was conducted to determine the effect of soil depth and roof slope on the stormwater retention of green roofs in Mississippi’s hot, humid climate. Simulated roof platforms were constructed to investigate two soil depths and two slopes, each replicated three times and planted with four species of Sedum. The green roof platforms significantly reduced runoff depth when compared with total rainfall depth. Soil depth and slope both significantly affected retention, with higher retention seen with increasing soil depth and lower retention seen with increasing slope. These results indicate that green roofs can be an effective tool to reduce runoff in Mississippi.

Urban stormwater management is evolving toward sustainable approaches which rely on dispersed small-scale bioretention BMPs. One such BMP is the flow-through planter, commonly applied in areas where infiltration into in situ soil is restricted or not possible. A project was developed to evaluate 18, vertically scaled flow-through mesocosms. Three replicates of six treatments, including four soil mixtures containing varied percentages of sand, compost and topsoil, were tested for orthophosphate and nitrate removal, volume reduction capabilities, and peak flow attenuation through the application of a synthetic solution over a simulated 2-inch, Type II storm event. Runoff volume was significantly (p < 0.05) reduced compared to controls. Nutrient levels observed along the hydrograph at different time-steps and flow rates revealed patterns not apparent in cumulative results. The observation of preferential flow patterns along with variability in nutrient removal across treatments highlights the need for design modifications of flow-through facilities.

Det råder idag en stor brist på information angående utvecklingen för gröna tak i Stockholms stad. Eftersom gröna tak har en stor potential att stödja stadens dagvattensystem, bidra till en ökad biologisk mångfald, minska buller samt förbättra luftkvalitet innebär att gröna tak stark kan kopplas till två av Sveriges miljömål nämligen god bebyggd miljö och ett rikt växt- och djurliv. På grund av denna potential vore det ofördelaktigt om gröna tak inte används fullt ut.  En inventering av gröna tak med hjälp av flygfoton har gjorts på en del av södra Stockholms stad för att avgöra hur mycket gröna tak som byggts de senaste nio åren jämfört med tidigare år. Området valdes på grund av stor åldersvariation i bebyggelsen för att kunna representera Stockholms stad som helhet bättre. Det har också genomförts 3 intervjuer, dels med representanter för Stockholms stad och dels från byggsektorn. Syftet med intervjuerna var att undersöka om det skett en ökning i byggandet samt orsaker till detta. Resultaten av inventeringen visar att det byggts lika många gröna tak de senaste nio åren som de byggts alla tidigare år i området. Intervjuerna visar på att det har skett en ökning av mängden byggda tak och att en av orsakerna till denna ökning har varit introduktionen av grönytefaktorn. Detta kan dock inte styrkas med någon befintligdata då sådan saknas för Stockholms stad som helhet. Utvecklingen för gröna tak utifrån denna studie framgår vara positiv dock för att helt kunna säkerställa gröna taks utveckling i Stockholm rekommenderas det att en mer utförlig inventering av hela Stockholms stads bestånd av gröna tak görs. / There is currently a great lack of information regarding the development of green roofs in Stockholm. Since green roofs have big potential to support the city's storm water system, contribute to increased biodiversity, reduce noise and improve air quality, green roofs can be strongly linked to two of Sweden's environmental goals, namely a good built environment and a rich plant and animal life. Because of this potential, it would be disadvantageous if green roofs were not fully used. An inventory of green roofs using aerial photos have been taken on a part of southern Stockholm to determine how much green roofs have been built over the past nine years compared to previous years. The area was chosen because of the large age variation in the buildings in order to better represent the city of Stockholm as a whole. There have also been 3 interviews conducted with representatives of the City of Stockholm and representatives from the construction sector. The purpose of the interviews was to investigate whether there has been an increase in construction and reasons for this. The results of the inventory show that as many green roofs have been built in the last nine years as has been built in the area all the previous years. The interviews show that there has been an increase in the amount of built roofs and that one of the reasons for this increase has been the introduction of the green area factor. However, this cannot be substantiated by any existing data, as such is missing for the City of Stockholm as a whole. The development for green roofs based on this study appears to be positive, however, in order to fully ensure the development of green roofs in Stockholm, it is recommended that a more detailed inventory of the entire Stockholm city stock of green roofs be made.

What are ecosystem services, what are the possibilities to use them as a solution to remediate environmental problems, and how can they be increased in an industrial area such as Rönnskärsverken? The aim of this master thesis was to investigate the potential and the incentive for increasing ecosystem services in Rönnskärsverken’s industrial area through green areas and nature based stormwater management solutions on the site.  Ecosystem services is a concept that was put on the political agenda in the UN in 2005 in order to create a common definition and valuation to raise awareness of the values that nature provides to human beings. In recent years it has become an important part when it comes to environmental work and sustainable development in many parts of the world. As cities grow and more areas are exploited it is important to acknowledge what's lost in its place, and find out how we can minimise our impact on the environment and help the ecosystems and biodiversity. The mining company Boliden AB has a smelter located outside Skellefteå in north of Sweden, on an island called Rönnskär. The industrial area has been expanded with artificial means since its inception in 1930 where the focus has then been on industrial function. This has led to few green areas and many impervious surfaces on the site, which in turn has led to problems with stormwater flows, diffuse dusting, noises from the industry, unfavourable wind conditions and a generally less pleasant environment. Boliden AB wants to investigate the possibilities of developing and benefiting ecosystem services of  the industrial site of Rönnskär, and wants knowledge about potential values and benefits. Information has been gathered and compilations and conclusions have been made through literature studies, a survey, a field visit and conversations with employees and expert staff. A digital GIS modelling was planned but not implemented, which is why there is a good basis with criteria in a table in the appendix for further investigation of placement of proposed solutions. In the report, 7 different environmental challenges are identified and addressed; stormwater management, diffuse dusting, noise, biodiversity, lack of green areas, outdoor environment and ground pollution. They have then been linked to 6 different measures using ecosystem services, whereupon stormwater management is further explored in a separate chapter (7). All proposals presented in the report are nature based to demonstrate the use of ecosystem services as tools and aids for the purpose.  The conclusion is that it is possible to use nature based solutions that benefit ecosystem services to remediate the environmental challenges Rönnskär is facing and at the same time also increase other aspects such as well-being, health and environment. For specific implementation further investigations need to be made. Close cooperation with the environmental department on Rönnskär is needed to investigate which measures are most important and to invest in first. Measures need to be taken, and it can clearly be seen that it would benefit the industrial site to invest in maintenance and expansion of green areas to reduce the environmental challenges they face. / Vad är ekosystemtjänster, hur ser möjligheterna ut för att använda dem som lösning för att åtgärda miljöproblem och hur kan de utökas i ett industriområde som Rönnskärsverken? Syftet med detta examensarbete var att undersöka potentialen och incitamentet för att öka ekosystemtjänsterna i Rönnskärsverkens industriområde genom grönområden och naturbaserade dagvattenhanteringslösningar på platsen. Ekosystemtjänster är ett begrepp som sattes upp på den politiska agendan i FN 2005 för att skapa en gemensam definition och värdering för att öka medvetenheten om de värden som naturen ger människor. På senare år har det blivit en viktig del när det gäller miljöarbete och hållbar utveckling på många håll i världen. När städer växer och fler områden exploateras är det viktigt att uppmärksamma vad som har gått förlorat i dess ställe, och ta reda på hur vi kan minimera vår påverkan på miljön, hjälpa ekosystemen och den biologiska mångfalden.  Gruvbolaget Boliden AB har ett smältverk beläget utanför Skellefteå i norra Sverige, på en ö som heter Rönnskär. Industriområdet har byggts ut med konstgjorda medel sedan starten 1930 där fokus legat på industriell funktion. Detta har lett till få grönområden och många ogenomträngliga ytor på platsen, vilket i sin tur lett till problem med dagvattenflöden, diffus damning, buller från industrin, ogynnsamma vindförhållanden och en generellt sett mindre behaglig miljö. Boliden AB vill undersöka möjligheterna att utveckla och dra nytta av ekosystemtjänsterna på industriområdet Rönnskär och vill ha kunskap om potentiella värden och nytta.  Information har samlats och sammanställningar samt slutsatser har gjorts genom litteraturstudier, en enkätundersökning, ett fältbesök och samtal med anställda och sakkunnig personal. En digital GIS-modellering var planerad men ej genomförd, varför det finns en god grund med kriterier i en tabell i appendix för vidare undersökning av placering av föreslagna lösningar.  I rapporten identifieras och behandlas 7 olika miljöutmaningar; dagvattenhantering, diffus damning, buller, biologisk mångfald, brist på grönområden, utemiljö och markföroreningar. De har sedan kopplats till 6 olika åtgärder med hjälp av ekosystemtjänster, varpå dagvattenhanteringen utforskas ytterligare i ett separat kapitel (7). Alla förslag som presenteras i rapporten är naturbaserade för att visa användningen av ekosystemtjänster som verktyg och hjälpmedel för ändamålet.  Slutsatsen är att det är möjligt att använda naturbaserade lösningar som gynnar ekosystemtjänster för att åtgärda de miljöutmaningar Rönnskär står inför och samtidigt också öka andra aspekter som välbefinnande, hälsa och miljö. För specifik implementering behöver ytterligare undersökningar göras. Det behövs ett nära samarbete med miljöavdelningen på Rönnskär för att utreda vilka åtgärder som är viktigast och att satsa på först. Åtgärder behöver vidtas och man kan tydligt se att det skulle gynna industriområdet att investera i underhåll och utbyggnad av grönområden för att minska de miljöutmaningar de står inför.

De aktuella klimatförändringarna skapar utmaningar för västkustens kommuner. Detta skapar möjligheter för den blå-gröna infrastrukturen att samspela med de traditionella dagvattenledningsystemen för att skapa en mer hållbar dagvattenhantering. Syftet med denna studie är därför att undersöka hur Kungsbacka, Halmstads och Varbergs kommun arbetar med hållbar dagvattenhantering i praktiken för att motverka framtida översvämningar samt att undersöka vilka faktorer som påverkar kommunernas arbete med blå-grön infrastruktur. Studien har en kvalitativ tillvägagångsmetod i form av dokumentanalys samt semistrukturerade intervjuer. Med utgångspunkt i hållbarhetsövergångsteorin Multi-level perspective har de framtagna dokumenten och intervjuerna analyserats vilket konstaterar att politikerna ofta försvårar utvecklingen av blå-grön infrastruktur. Även utmaningar som geotekniska förutsättningar och markbrist påverkar den blå-gröna infrastrukturens möjlighet att frodas. Den breda tolkningen som kommunerna har av begreppet hållbar dagvattenhantering bidrar till en vidareutveckling av den blå-gröna infrastrukturen. Även klimathändelser påverkar den blå-gröna infrastrukturens förutsättning för genomslag hos den traditionella dagvattenhanteringen. / Climate change is creating challenges for the municipalities on the West Coast. This provides opportunities for blue-green infrastructure to collaborate with traditional stormwater management systems to create more sustainable stormwater management. The purpose of this study is therefore to investigate how the municipalities of Kungsbacka, Halmstad, and Varberg are working with sustainable stormwater management to counteract future flooding, and to examine the factors that affect the municipalities' work with blue-green infrastructure. Based on the sustainability transition theory Multi-level perspective, the documents and interviews have been analyzed, which states that politicians often hinder the development of blue-green infrastructure. Challenges such as geotechnical conditions and land shortage also affect the blue-green infrastructure's ability to thrive. Municipalities' broad interpretation of sustainable stormwater management promotes the sustainable stormwater management and therefore blue-green infrastructure development. Climate events affect the conditions for breakthroughs in traditional stormwater management.

When precipitation increases as a result of climate change during certain periods, demands are placed on how cities can cope with the increased handling of stormwater, rainwater and meltwater runoff. Umeå is a city with the vision of reaching 200,000 inhabitants by the year 2050 and that growth must be managed with ecological, economic, social and cultural sustainability. In a growing city, it is therefore important to include stormwater management as a central part of planning. This study aims to describe and analyze how the municipality of Umeå works towards a sustainable stormwater management. This will be done with the methods of document analysis and field studies.

Developments that have been taking place on Cal Poly campus over the years have altered the natural hydrology of the area. Stormwater management practices could help reduce the impacts of these developments. Computer models can help to design effective and economical stormwater management solutions at a watershed scale. As such, the objective of this study was to develop a stormwater management model for Cal Poly campus. The model was developed based on the utility data obtained from the university and other watershed data available from open sources. Field surveys were conducted to address some anomalies in the utility data, and streamflow monitoring was performed. The model was calibrated using the streamflow data measured during this study. The calibration effort significantly improved the prediction accuracy of the model. The calibrated model was then used to analyze the hydrologic performance of implementing LID systems for two projects that Cal Poly plans to build. Permeable Pavements (PPs) and Bioretention Cells (BRCs) were the LID types examined. The LIDs were evaluated based on peak flow and runoff volume reductions they would achieve. The potential reductions were compared for current conditions and the proposed project if LIDs were implemented, and for inflows to the LIDs and outflows from the LIDs. The results indicate that implementing a PP system for the proposed student apartment at the current H-1 and R-1 parking lots and a BRC system for the proposed engineering project facilities at the current H-2 parking lots will significantly reduce peak flow and runoff volume. Overall, the developed model will help the university with the traditional stormwater management practices such as flood control and to identify effective LID practices for future developments. Limitations of the current model and recommendations on how to improve the model are also discussed.

Stormwater sewer infrastructure is at risk due to ageing, structural deterioration, population growth, and climate change. Since the consequences of the sewer system failure can adversely impact the community safety, environment and economy, a resilient infrastructure system is of essential importance. However, limited reinvestment budget and insufficient asset management practices impact the rehabilitation of urban sewerage systems. Therefore, an effective and efficient rehabilitation plan is needed to help proper investment decisions. An effective rehabilitation plan will maximize hydraulic performance while minimizing the overall failure risk within a limited budget. The current study aims to address this issue through designing a risk-informed methodology in three steps. First, the hydraulic risk index (obtained using the SWMM model) was combined with the ageing pipe index. The framework uses multi-objective optimization technique to generate solutions under specific sewerage conditions. We named this new framework as Hydraulics and Risk Combined Model (HRCM). Several scenarios including high hydraulic risk, high ageing risk, hydraulic risk and ageing risk (combined problems), and limited budget problems, are used to test the performance of the proposed methodology. The results show that the proposed model could provide a satisfactory solution. Then, in order to increase the calculation speed and improve the accuracy, sensitivity and cost-effectiveness analyses were also conducted for the proposed methodology with different algorithms. The results show that different algorithms offer various benefits. A new calculation method was offered by combining the advantages of the previous methods. Finally, a new optimization method named Phenotype Searching Method, which was enlightened by sexual selection processes, was offered. This method can enhance the selection processes to specific phenotypes (pipes) so that it can increase the convergence speed and increase the performance of the HRCM model.