Sustainable Drainage Research Articles

Reduction in pollution load to an urban estuary using a sustainable drainage system treatment train

Rapid urbanisation and industrialisation have placed increased pressure on the ecosystem health of urban estuaries. Sustainable drainage systems (SuDS) are globally accepted practices for managing the water quality of stormwater and effluent discharged into urban systems. The Swartkops Estuary in South Africa is a heavily urbanized estuary that has a long history of pollution, specifically trace metal contamination, originating from industrial sources and urban wastewater. Using a novel SuDS treatment train, the physical characteristics (total suspended solids), macronutrients (orthophosphates, nitrate, ammonium), trace metals (As, Cd, Hg, Fe, Pb, Cu), and E. coli concentrations were measured monthly for one year, both before and after the treatment train. The treatment train consisted of five interconnected 500 L plastic tanks for sedimentation, filtration (sand and stone), biodegradation and floating wetlands. Results indicate that the SuDS treatment train provided an efficient method in reducing the pollution load to this urban estuary, by reducing macronutrient concentrations by 76 %, trace elements concentrations by 74 % and faecal bacteria counts (E. coli) by 80 %.

Adapting drainage networks to the urban development: An assessment of different integrated approach alternatives for a sustainable flood risk mitigation in Northern Italy

Political bodies, planners and the scientific community agree on the need for making cities and communities resilient and sustainable in the near future. Urban infrastructures generate too often negative impacts on the surrounding environment. Hence, it is considered today an absolute priority implementing actions able to generate an optimal relationship between citizens and the environment. Even in the field of hydraulic constructions and urban hydrology, it is therefore essential to develop water management strategies able to contribute to the definition of this new paradigm of city. With regard to flood management, integrated strategies including the combined implementation of Stormwater Detention Tanks and Sustainable Drainage Strategies (SuDS) seem successful solutions but additional studies are required to define their potential. This research aims at assessing and comparing different integrated drainage alternatives involving the single or combined implementation of two categories of SuDS in Sesto Ulteriano (Northern Italy): Green Infrastructures (GI) and flood control areas. The Hydraulic Risk Mitigation Index (HRMI), is here proposed to account for different hydraulic parameters in the performance assessment of an integrated drainage strategy. Results highlighted the importance of HRMI as decision support measure and the effectiveness of SuDS strategies, especially those involving GI, at reducing urban flooding.

Study of Continuous Simulation Supporting Multiple Design Criteria for Sustainable Drainage Systems

Study of Continuous Simulation Supporting Multiple Design Criteria for Sustainable Drainage Systems

Flow Characteristics in Perforated Subsurface Drain of Drainage System Application: Case Study of Gate Fully Open with Longitudinal Slope 1/500

Subsurface drainage is part of a sustainable drainage system's components. This component represents the infiltration of stormwater into the subsurface drainage system for flow attenuation purposes. This study examines the flow parameters of subsurface drainage components. The laboratory validation of perforated subsurface drains was conducted at a longitudinal slope gradient of 1/500 with the Gate Fully Open. The manning, n data obtained in these experiments varies with several hydraulic parameters. Therefore, the experimental relationship between the flow characteristics of these subsurface drain components has been investigated. The relationship between flow behavior has been determined. The sub-critical and supercritical, and turbulence flow has occurred in this study.

SuDS as a climate change adaptation strategy: Scenario-based analysis for an urban catchment in northern Italy

Urbanization and climate change effects on precipitation are the leading cause of flood risk increase in urban settlements. Sustainable Drainage Systems (SuDS) are effective strategies to improve city resilience toward flooding but usually they are designed to meet performance standards based on historical climate settings. The reported modeling scenario-analysis strives for investigating the potential of SuDS as adaptation strategy to a projected medium-term climate change affecting Sesto Ulteriano (Milan, Northern Italy). Two drainage models, a benchmark scenario reproducing the drainage network current configuration and a designed scenario involving SuDS retrofitting, were tested under historical (observed) and expected future precipitation extremes (projected) to assess and compare hydrological and hydraulic variables essential for the definition of a Precipitation Variability Adaptation Index (PVAI), which measures the adaptation strategy performance. Results indicate that even though SuDS were confirmed as effective flood control measures, their adaptability potential is affected by changes in rainfall severity indeed. In particular, the multi-variable PVAI, a global index able to take into account the effects of different determinants for an overall assessment of SuDS potential as adaptation strategies to climate changes, decreases when rainfall frequency decreases, among the same climate scenario, or when rainfall intensity increases due to climate changes.

Planning Interventions to Develop Blue Green Infrastructure on the Verge of Water Sensitivity: A Case of Lucknow, Uttar Pradesh

This abstract emphasises the significance of planning interventions to construct blue-green infrastructure in Lucknow, Uttar Pradesh, on the border of water sensitivity. Blue-green infrastructure is a sustainable method that blends natural and engineered systems to manage water resources, boost urban resilience, and improve the quality of life in metropolitan environments. Due to urbanisation and climate change, Lucknow, the capital of Uttar Pradesh, is confronted with considerable water sensitivity challenges. Through the deployment of blue-green infrastructure, this research aims to provide planning strategies that successfully solve the water sensitivity concerns in Lucknow. The interventions emphasise the integration of green areas, water management systems, and sustainable drainage systems in order to reduce floods, improve water quality, and boost ecosystem services. The findings of this study contribute to the expanding body of information about the construction of blue-green infrastructure in water-sensitive metropolitan regions. The recommended planning interventions offer policymakers, urban planners, and local authorities with a road map for promoting resilience and sustainable development in Lucknow.

An exploratory methodology based on high resolution remote sensing techniques for soil moisture determination with prospective applications in vegetative SuDS

ABSTRACT Sustainable Drainage Systems (SuDS) monitoring is very often intrusive and need onsite personnel to be carried out. The application of remote sensing in SuDS still is an area for further development, especially in vegetation-based techniques, representing a gap in the field. This research proposes an exploratory method combining Synthetic Aperture Radar (SAR) images data and onsite measurements to develop models of performance. Linear regression models were obtained for the computing of the soil moisture using the following variables: backscatter coefficient (σ°), temperature, normalized difference vegetation index (NDVI) and topographic wetness index (TWI), reaching medium to high values for its predictive capacity, ranging from 0.53 and 0.66 using σ° and temperature. The most influential variable was found to be the temperature. This investigation opens the path for future research in the use of remote sensing tools in vegetation-based SuDS monitoring with homogeneous plant species, highlighting the need for further research.

Understanding the stakeholder knowledge about, the mindset of and the power for the sustainability transformation of urban stormwater systems: An empirical analysis of three European urban districts

The implementation of Sustainable Drainage Systems (SuDS) is believed to have the potential to bring about extensive change in stormwater management. This includes change in the crucial but still relatively little researched institutional context (prevailing mindset, etc.) shaping practice. This paper contributes to the further understanding of the institutional context surrounding SuDS deployment. Stakeholder knowledge, mindset, and power (both perceived and exercised) are explored, embracing divergences between district types (districts with SuDS and districts without SuDS), stakeholder groups (residents and various professionals), and two European socio-ecological contexts (Austria and Southern France). Results show increasing support for SuDS implementation and ambitious approaches to stormwater management, although the latter in particular rarely has any effect in practice. A sharp dichotomy persists between residents and professionals in terms of knowledge and exercised power. Daily experience with SuDS rarely has any influence on residents' knowledge and mindset, regardless of their demographic, social and geographical characteristics. Stakeholders appear motivated but tend to feel incapable of contributing to change. Information campaigns and the provision of empowerment tools to those individuals who feel motivated, but unaware of their capabilities, need to be developed in order to enable further change.

Experiences from a School–University Partnership Climate and Sustainability Education Project in England: The Value of Citizen Science and Practical STEM Approaches

Extracurricular citizen science and hands-on STEM (science, technology, engineering, and maths) projects can ensure that climate and sustainability education is not just superficial but truly transformative. Through working under the guidance of academic partners, young people can develop a deep appreciation for climate science and, most importantly, become aware of the real-world sustainable solutions being developed to address the consequences of our changing climate. We present the experiences of four stakeholders from one case study involving middle school students (9–13 years) and their teachers working on a climate change and sustainable drainage system (SuDS) project with academics from Newcastle University and the Schools Engagement programme of the Royal Society. We found that all stakeholders considered it to be a successful project with significant benefits, including engaging learning in the pupils, a challenge for the teachers, and meaningful data collection for the academic team. The funding organisation thought the positive interactions that they try to encourage between students and STEM partners were evidenced in this project perfectly. Young people are future decision makers; this type of project can enable them to develop essential skills and an understanding of a range of STEM careers. Subsequent developments may include refining the way similar projects are run.

A new framework for distributed storage tanks placement based on a resilience characteristic metric and reduced modelling

In recent years, urban flooding has been a frequent occurrence, and seriously threatens the safety of lives and properties. Rational placement of distributed storage tanks is one of the effective ways to solve urban flooding, addressing stormwater management and rainwater reuse. However, existing optimization methods (such as genetic algorithm (GA) and other evolutionary algorithms) for determining the placement of storage tanks typically have a high computational burden; as such, they can be very time-consuming, and are not conducive to energy saving, carbon reduction and work efficiency improvements. In this study, a new approach and framework based on a resilience characteristic metric (RCM) and reduced modelling requirements are proposed. In this framework, the resilience characteristic metric, which is based on the linear superposition principle of system resilience metadata, is introduced, and a small number of simulations based on a coupling of MATLAB with SWMM are used to obtain the final placement scheme of storage tanks. The framework is demonstrated and verified with two cases in Beijing and Chizhou, China, and compared with a GA. The GA requires 2000 simulations for two cases (considering the placement of 2 and 6 tanks respectively), while the proposed method needs 44 simulations for the Beijing case and 89 simulations for the Chizhou case. The results show that the proposed approach is feasible and effective, and cannot only obtain a relative better placement scheme, but also considerably reduce computational time and energy consumption. It significantly improves the efficiency of determining the placement scheme of storage tanks. This method provides a new approach for the determining better storage tank placement schemes, and is useful for informing device placement in sustainable drainage systems.

Accuracy Assessment of Surveying Strategies for the Characterization of Microtopographic Features That Influence Surface Water Flooding

With the increase in rainfall intensity, population, and urbanised areas, surface water flooding (SWF) is an increasing concern impacting properties, businesses, and human lives. Previous studies have shown that microtopography significantly influences flow paths, flow direction, and velocity, impacting flood extent and depth, particularly for the shallow flow associated with urban SWF. This study compares two survey strategies commonly used by flood practitioners, S1 (using Unmanned Aerial Systems-based RGB data) and S2 (using manned aircraft with LiDAR scanners), to develop guidelines on where to use each strategy to better characterise microtopography for a range of flood features. The difference between S1 and S2 in elevation and their accuracies were assessed using both traditional and robust statistical measures. The results showed that the difference in elevation between S1 and S2 varies between 11 cm and 37 cm on different land use and microtopographic flood features. Similarly, the accuracy of S1 ranges between 3 cm and 70 cm, and the accuracy of S2 ranges between 3.8 cm and 30.3 cm on different microtopographic flood features. Thus, this study suggests that the flood features of interest in any given flood study would be key to select the most suitable survey strategy. A decision framework was developed to inform data collection and integration of the two surveying strategies to better characterise microtopographic features. The findings from this study will help improve the microtopographic representation of flood features in flood models and, thus, increase the ability to identify high flood-risk prompt areas accurately. It would also help manage and maintain drainage assets, spatial planning of sustainable drainage systems, and property level flood resilience and insurance to better adapt to the effects of climate change. This study is another step towards standardising flood extent and impact surveying strategies.

Evaluation of bioswale efficiency in consideration of climate and design features: A case study in Hong Kong

Sustainable drainage systems (SuDSs) have been increasingly implemented to mitigate the stress of urbanisation, climate change, and water scarcity. However, SuDS construction in densely populated metropolitan cities with a subtropical monsoon climate such as that of Hong Kong may encounter challenging field conditions and site constraints. This fieldscale study aimed to verify the performance of bioswale for flood resilience and water quality improvement under various simulated rainfall scenarios with different intermittency and intensity. In the six simulated rainfall events, the results showed that metal removal and flow attenuation were excellent under minor and moderate rainfall events, while the system performance was compromised during intensive rainfall events. The removal of turbidity and nutrients from the runoff was moderate owing to the low contaminant levels in the synthetic stormwater. The dry state of soil media led to more fluctuating results for water quality control. To further enhance the treatment capability under practical site constraints, the addition of appropriate soil amendments and the integrated use of different SuDS measures are recommended in order to achieve sustainable development goals and resilient water management.

Evaluation of bioswale efficiency in consideration of climate and design features: A case study in Hong Kong

Sustainable drainage systems (SuDSs) have been increasingly implemented to mitigate the stress of urbanisation, climate change, and water scarcity. However, SuDS construction in densely populated metropolitan cities with a subtropical monsoon climate such as that of Hong Kong may encounter challenging field conditions and site constraints. This fieldscale study aimed to verify the performance of bioswale for flood resilience and water quality improvement under various simulated rainfall scenarios with different intermittency and intensity. In the six simulated rainfall events, the results showed that metal removal and flow attenuation were excellent under minor and moderate rainfall events, while the system performance was compromised during intensive rainfall events. The removal of turbidity and nutrients from the runoff was moderate owing to the low contaminant levels in the synthetic stormwater. The dry state of soil media led to more fluctuating results for water quality control. To further enhance the treatment capability under practical site constraints, the addition of appropriate soil amendments and the integrated use of different SuDS measures are recommended in order to achieve sustainable development goals and resilient water management.

Sustainable Drainage Technologies Under the Sustainability Tripod Perspective

The management of drainage and urban rainwater management in Brazil and in the world faces numerous challenges in order to be sustainable. When dealing with sustainability, it is important to relate the aspects: of social, environmental and economic, known as the sustainability tripod. Compensatory urban drainage techniques, through infiltration or detention and increasing the evapotranspiration rate, have the potential to reduce: the amount of rainwater runoff; flow peaks; vulnerability of urban areas to flooding; contamination of water courses. It is important that, even with all these benefits, such technologies are associated with such aspects. In this context, this systematic review article (SR) was developed, which aimed to identify trends in the use of sustainable drainage technologies adopted in Brazil and in the world, relating them to aspects of sustainability. For that, a systematic review (SR) was carried out in which the following were identified: trends in the adoption of technologies for sustainable drainage in the world and in Brazil; and the terms used and related to technologies for sustainable drainage. It was also observed, both in Brazil and in the world, that the approach to the theme begins with the technological aspect involving the implementation, life cycle and maintenance of sustainable technologies and, in sequence, the environmental, economic and social aspects unfold in this order, but which are not done in an integral way. It was possible to characterize an important knowledge gap.

Research and Experience Reference on London’s Response to Climate Change in the Twenty-first Century

London’s approaches to tackling climate change after the 21st century are multifaceted and relatively systematic. The aim of this research paper is to analyse London’s actions in response to climate change and to draw out what valuable lessons London has for the world in terms of its response to climate change. This paper provides an in depth analysis of London’s policies and actions on climate mitigation in the areas of “greenhouse gas emissions” and “energy infrastructure”, and climate adaptation actions in the areas of “city green belt and urban afforestation”, “UHI and thermal crisis management” and “water supply infrastructure and sustainable drainage”. It then examines the positive aspects of these actions to determine what London has to say about climate change to the rest of the world and other cities. This paper also discovers that to effectively mitigate and adapt to climate change, London has not only established carbon reduction targets, but also created a large academic research network, represented by the LCCP. At the same time, London has developed a scientific climate change adaptation planning framework (P2R2) that focuses on four key areas: Economic, environmental, health, and infrastructure sectors, and three types of risks: Flooding, heat, and water supply, and emphasizes the dynamics and flexibility of each adaptation strategy

Unmanaged vegetated roofs hydrological performance in subtropical areas: An investigation in São Paulo, Brazil

Extensive vegetated roofs are Nature-based Solution with the ability to manage rainwater runoff in densely built spaces. Despite the large amount of research demonstrating its water management abilities, its performance is poorly quantified under subtropical climates and when using unmanaged vegetation. The present work aims at characterizing the runoff retention and detention of vegetated roofs under the climate of São Paulo, Brazil, accepting the growth of spontaneous species. By using real scale prototypes under natural rain, a vegetated roof hydrological performance was compared with a ceramic tiled roof. By using models with different substrate depths under artificial rain, changes in the hydrological performance were monitored for different antecedent soil moisture contents. Results from the prototypes showed that the (i) extensive roof attenuated from 30 % up to 100 % the peak rainfall runoff; (ii) delayed the peak runoff from 14 up to 37 min and (iii) retained from 34 % up to 100 % the total rainfall. Furthermore, results from the testbeds indicated that (iv) when comparing two rainfalls with same depths, the one with longer duration can saturate more the vegetated roof and thus undermine more its ability to retain water; and (v) when not managing the vegetation, the vegetated roof's soil moisture content loses correlation with the substrate depth, as plants will also develop more and will more effectively restore the substrate retention capacity. Conclusions point to extensive vegetated roofs as a relevant sustainable drainage system in subtropical areas, but demonstrate that its performance is highly dependent on structural factors, weather factors and level of maintenance. Such findings are expected to be useful for practitioners dimensioning these roofs as well as for policy makers towards a more accurate standardization of vegetated roofs in subtropical regions and Latin American developing countries.

Evaluation of a Modular Filter Concept to Reduce Microplastics and Other Solids from Urban Stormwater Runoff

This paper describes an innovative Decentralized Technical Sustainable Drainage System (SuDS) concept, which is based on technical devices, such as sieves, sedimentation barriers, floating barriers and a magnetic module, which addresses, mainly, the fine matter. The SuDS is designed as a retrofit system so that no costly and time-consuming conversion measures are necessary. Due to the possibility of free configurability of individual modules in the three levels, road, gully and drain, a novel solution approach is presented, which is not available on the market, for a reduction in solids in general and microplastics in particular. The retention performance of selected modules and their combinations is demonstrated by means of bench tests according to the test procedure of the German Institute for Construction Engineering (DIBt) for the evaluation of decentralized treatment systems. Four different rain intensities, from light to medium up to heavy rain, are charged to the filter modules. Collected and fractionated road-deposited sediment (RDS) was selected as the test substance (10 kg). Additional tests with tyre powder, PE pellets, cigarette butts and candy wrappers helped to make clear the filter process of the particulate matter. The retention performance was determined by the mass balance between the defined dosage and at the outlet. For this purpose, the total volume flow of the effluent was passed over a stainless-steel sieve with a diameter of 600 mm and a mesh size of 20 µm. For the test substance, RDS retention rates up to 97% were measured. Very fine matter, particularly, was technically challenging to obtain; <63 µm up to 66% could be retained by the filter modules. Modules in the road space, such as porous asphalt or additional retention spaces, in the area of the curb as well as direct infiltration in the road drainage shaft are theoretically described and discussed. The outlook also addresses the potential of an intelligent network to reduce the input of pollution from urban stormwater runoff.

Assessment of the thermal properties for the geothermal use of a permeable pavement structure for pedestrian and cycle paths

Sustainable Drainage Systems (SuDS) have positioned themselves as one of the most widely applied Green Infrastructure (GI) techniques for sustainable stormwater management. In recent decades, new lines of research have emerged leading to the geothermal use of SuDS. The aim is to optimise available space in cities and minimise dependence on non-renewable energy sources. Previous research has focused on determining the feasibility of combining the two technologies, both in laboratory and field studies. Other aspects such as the influence of the surface geothermal system on the quality of the water present in the SuDS were also studied. This previous research has focused mainly on permeable pavements, positioning them as one of the SuDS techniques of reference in this line of research. This article attempts to give continuity to what has been established by other authors. It studies in depth the thermal properties of a complete section of permeable pavement under different hydraulic operating conditions. To this end, a complete section of a permeable pavement has been simulated in the laboratory using Hot-Box tests as set out in different international standards. With these tests, the values of thermal transmittance and equivalent thermal conductivity were determined. The aim of this research is to establish a test procedure for the thermal properties of permeable floorings, based on standardised equipment. The aim is to better understand the heat transfer procedures inside SuDS. In this way, it will be possible to optimise the design of these in combination with surface geothermal elements.

A review of the sustainable drainage technics suitable for paved roads in the tropical area: the case of Douala city

A review of the sustainable drainage technics suitable for paved roads in the tropical area: the case of Douala city

Technology prospection for sustainable drainage systems as a means to propose changes in the Master Plan of the Municipality of Frutal, Minas Gerais

RESUMO Sistemas de drenagem urbana sustentáveis (SUDS) são tecnologias que dispensam as tradicionais galerias pluviais e têm como premissa a sustentabilidade. Frutal, município do estado de Minas Gerais, sofre com problemas de drenagem pluvial e está em processo de atualização de seu plano diretor. O objetivo do trabalho é discutir, em termos teóricos, a aplicação dos SUDS nesse município, apresentando sugestões para seu plano diretor, bem como realizar a prospecção de tecnologias SUDS para fundamentar futuros estudos técnicos acerca da aplicação dessas tecnologias em Frutal, contribuindo com a literatura sobre SUDS. Para tanto, adotou como procedimentos metodológicos o estudo de caso, a revisão de literatura e o mapeamento de patentes. Como resultados, o trabalho identificou os pontos críticos de inundações e processos erosivos em Frutal, enfatizando os problemas de inundação nos bairros Centro, XV de Novembro, Princesa Isabel, Jardim das Laranjeiras, Progresso, Novo Horizonte e Caju, e de processos erosivos nos bairros Ipê Amarelo e Waldemar Marchi. Expôs uma série de diretrizes sobre os SUDS que poderão nortear eventuais mudanças no plano diretor e futuros projetos legislativos e técnicos, como incentivos econômicos e campanhas de conscientização acerca dessa tecnologia, e fornece exemplos de tecnologias patenteadas que poderão ser referência para posteriores ações de drenagem urbana, especialmente do tipo pavimentos permeáveis, sobretudo para áreas com elevado índice de ocupação do solo e com dificuldades para instalação de equipamentos superficiais de drenagem.