Sustainable Drainage Systems Research Articles

Clog-Resistant Permeable Pavement: Methods of Performance Measurement

Permeable pavements are considered to be one of the effective measures for LID (i.e. Low Impact Development) and SUDS (i.e. Sustainable Urban Drainage System) globally. The major three types of permeable pavements are (a) pervious concrete (PC), (b) previous asphalt (PA), and (c) permeable interlocked concrete paver (PICP). The performance of all types of permeable is satisfactory at the start of the service life but greatly reduced if not maintained on time. Considering the long lengths of the pavements, measurement of permeability at different locations is a cumbersome and tedious task. Therefore, ease of performance and realistic results are of vital importance. In this study, ASTM C1701/C1701M—17a single ring infiltrometer, Stormwater Infiltration Field Test (SWIFT), and NCAT permeameter Methods are discussed in detail and examined for their relative ease of setting-up, versatility and performance. It is concluded that ASTM C1701/C1701M—17a single ring infiltrometer is the most versatile, easy to set up and produces accurate results.

Discharge coefficients formulae of grate inlets of complicated conditions for urban floods simulation and urban drainage systems design

With the acceleration of climate change and urbanization, all over the world is widely facing serious urban flooding problems. Grate inlets are key elements for the discharge exchange of surface flows and underground sewer flows in urban floods, so the accurate calculation of the overflow discharges of the grate inlets is related to the accurate simulation of the urban flood evolution process, which also plays an important role in the design of sustainable urban drainage systems. This study investigated the discharge coefficients of six types of grate inlets under different approaching discharges, transverse and longitudinal road slopes through 285 indoor 1:1 tests, mainly focusing on the supercritical flow conditions with less attention before. The experimental results show that: (1) With all other parameters being equal, as the interception discharge Q increases, the discharge coefficient increases. When the approaching Froude number increases, the discharge coefficient also decreases. The performance of parallel grate inlets in terms of discharge coefficients is not significantly different from that of vertical grate inlets. (2) Using Buckingham’s theorem of dimensional analysis, 12 groups of accurate grate inlets discharge coefficient calculation formulae were creatively proposed. The average relative errors of the 12 groups of formulae are 0.37% ∼ 5.41%, indicating that the calculated values of the formulae and the measured values are in good agreement. (3) The discharge coefficients of grate inlets were found to show a strong dependence on the Froude number of the approaching discharge, being in agreement with previous study result. But the relative error of individual data in this method is large, so the use of equations with more influencing parameters is recommended. A novel and effective method was also proposed to calculate the interception discharge of the grate inlets by iteration. This study can provide important references for the design and selection of grate inlets for urban drainage systems and also provide support for accurate simulation of urban floods.

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 %.

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.

A transdisciplinary approach for assessing the potential feasibility of Sustainable Urban Drainage Systems: case study, Bogotá, Colombia

ABSTRACT Rapid population growth and urban sprawl have expanded built-up areas, affecting flood patterns in cities. Sustainable urban drainage systems (SUDS) have gained significant attention by attempting to replicate natural pre-development drainage conditions. This paper presents a new transdisciplinary methodology for assessing the potential feasibility of 12 different SUDS typologies by considering physical restrictions and six types of contextual barriers. The approach integrates input from academic and non-academic actors, fuzzy logic, geographic information system tools, and multi-criteria decision analysis. A neighborhood in Bogotá, Colombia, was selected as the unit of analysis, framing a relevant case study for highly urbanized areas. The findings demonstrate the differential impact of local context constraints and emphasize the importance of comprehensive approaches to SUDS planning that consider criteria other than technical. The methodology is a tool to support architects, engineers, urban planners, and urban water decision-makers in the planning of sustainable and flood-resilient cities.

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.

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.

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.

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.

Mapping Public-Planner Conflicts in SUDS Implementation Using Cultural Dimensions—A Case Study

The timely implementation of climate adaptation measures for the urban environment is essential to the creation of robust cities. Within Norway, these adaptation measures are undertaken at the municipal level. Unfortunately, the implementation of adaptation measures has lagged behind expectations, partially due to public resistance to local projects. City planners seek tools to provide insight into the priorities of residents to build consensus and public support. This study follows up on two previous case studies of Sustainable Urban Drainage System (SUDS) implementation in Trondheim, Norway, where the prioritization of urban space is often a source of conflict. The Hofstede Cultural Compass is a tool that maps six cultural dimensions used in research and practice to inform users about cultural norms and cross-cultural divergences. This study seeks to test and verify this tool for use in building public consensus and support. Municipal managers responsible for project implementation took the Cultural Compass survey, and the results were collectively mapped and compared to the public at large. The Cultural Compass found notable divergences between the municipality and the Norwegian public within the areas of “Long-term Orientation”, “Uncertainty Avoidance”, and “Masculinity vs. Femininity”. These findings were cross-referenced with thematically analyzed interviews of residents regarding their perceptions of a municipal SUDS project. Together, these case studies give greater insight into the issues of diverging priorities and perspectives experienced in the implementation of SUDS. Recommendations are presented to aid the understanding of intercultural divergences between planning offices and public priorities in an effort to better engage the public and build consensus.

Hydrologic-hydraulic assessment of SUDS control capacity using different modeling approaches: a case study in Bogotá, Colombia.

Urban flooding has increased in response to impervious surface intensification, the loss of green areas, and high-intensity rainfall associated with climate change. Sustainable urban drainage systems (SUDS) are an appealing option for stormwater management; however, their hydraulic control capabilities have received little attention. We developed a comparative model-based approach with 24 scenarios to contrast the hydrologic and hydraulic response of a highly discretized (HD) 1D model and a coupled 1D-2D model, considering the impact of rainwater harvesting systems and tree pits. An additional scenario was modeled including attenuation storage tanks, green roofs, and pervious pavements. A heavily urbanized flood-prone catchment with severe land-use constraints in Bogotá, Colombia, was selected for analysis. The findings revealed that SUDS can contribute to reducing the number of flooded junctions, overloaded conduits' length, overloading time, nodal inundation depth, and waterlogging extent. Furthermore, the HD 1D model can reproduce the coupled 1D-2D model results in terms of hydrologic response and some hydraulic control indicators. Further research is needed for an accurate description of the internal hydraulic mechanisms of SUDS interacting with overland flow. The key findings of this study provide model-based evidence to support urban stormwater management decision-making in data-scarce environments.

Nature-based solutions for urban stormwater management: an overview

The coupled effect of urbanization and climate change led to several environmental and socioeconomic impacts, such as the impoverishment of ecosystems, flooding risk, water quality deterioration, air pollution, urban heat island effect, and other socio-environmental. From a hydraulic perspective, the constant loss of natural areas was reflected in a drastic alteration of the hydrological cycle that, combined with the growth of extreme rainfall frequency, increased the city’s vulnerability to flooding risk, highlighting the inadequacy of traditional urban drainage systems. In this context, a transition towards sustainable and resilient urban drainage systems becomes essential. Thus, this paper aims to present an overview of Nature-based solutions, which, due to their capacity to reduce surface runoff and increase evapotranspiration and infiltration rates, represent valuable options for stormwater management and hydrological cycle restoration in urban areas. In this regard, the paper is conceived and structured by considering first a general introduction to nature-based solutions. The general design features of some nature-based solutions (green roofs, green walls, rain gardens, and permeable pavements) are shown, and finally, the hydrological effectiveness of these systems is discussed by considering the results found in the literature.

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.

A contemporary approach on water sensitive urban design for sustainable urban development

There are a number of irreversible environmental impacts associated with urbanization, such as soil degradation, a reduction in biodiversity, and temperature rises. Run-off flows are rising as a result, and sanitary networks are having issues, which leads to spills and floods. They are a collection of water management methods and infrastructural elements, as opposed to the traditional practise of letting water drain into rivers. By planning our streets and public areas, we can improve both the environment and the quality of life in our communities. Sustainable Urban Drainage Systems (SUDS) have frequently been put into place with the primary goal of mitigating drainage issues brought on by poor landscaping. For better integrating water cycles, urban planning, and landscaping in urban areas, a set of criteria for WSUD (Water Sensitive Urban Design) is recommended.

Merging Green and Active Transportation Infrastructure towards an Equitable Accessibility to Green Areas: Barcelona Green Axes

The UN’s 2030 Sustainable Development Goals (SDGs) call for the provision of universal access to: (a) safe, inclusive, and accessible green and public spaces, and (b) safe, affordable, accessible, and sustainable transport systems for all. The Barcelona green axes plan aims to transform one third of the streets within its 19th century extension grid, increasing the tree cover and the vegetation, adopting sustainable urban drainage systems, limiting motor traffic, and providing a safer and more comfortable environment for pedestrians, cyclists, and other social activities in healthier environments. These transformations become even greater at the intersection of the axes, where former traffic junctions are becoming squares and urban gardens. This study gives an in-depth analysis of the origins of the superblocks plan, the rationale behind the transformation, and the implementation process. The GIS-based analysis shows how the green axes and the new square gardens (a) transform the city’s disconnected urban green areas into a more interconnected green infrastructure system, and (b) significantly increase accessibility to green areas. The study reveals this strategy’s potential to create a city of proximity, improve the well-being of the population, and build a more equitable city, which could be a useful tool for planning and decision making at both city and regional levels.

Sets of infiltration models for water infiltration in sustainable urban drainage systems

Infiltration is a crucial process in various fields such as hydrology, agriculture, urban soils, and particularly for Sustainable Urban Drainage Systems (SUDS) operation. Over the past century, the physics of infiltration has been extensively studied by developing models that estimate the dynamics of infiltration. In this study, three physically-based infiltration models (CH1, CH2, and CH3) have been developed as part of the Canoe Hydrobox (CH) platform, designed to simulate and evaluate the performance of SUDS. The three models rely on similar approaches to the Green-Ampt (GA) model by describing the water flux as the product of the equivalent hydraulic gradient and the equivalent hydraulic conductivity. The models differ in their ways of defining the hydraulic gradient and conductivity from the hydric conditions, soil parameters, and geometric features. The two first models (CH1 and CH2) consider an increase in the hydraulic conductivity with infiltrated water amount, whereas the last model (CH3) considers only the saturated hydraulic conductivity. For the hydraulic gradient, the first model considers the difference between the surface water pressure head and the height of infiltrated water. The other two models consider the difference between the surface water pressure head and the isostatic water pressure head at the surface in equilibrium with the height of infiltrated water. These models were applied to simulate water infiltration processes into dry, wet, and intermediate-wet soils. We compared these results with the numerical solution of the Richards equation using HYDRUS software. The comparison allowed the assessment of the capability of CH models to satisfy the critical principles of soil water infiltration. Subsequently we used the three models to invert six real experimental infiltration data to test their capability to work in inverse mode. The two models (CH1 and CH2) produced specific time-evolution of infiltration rates in disagreement with the physics of water infiltration under regular conditions (e.g., no water repellence). The third model (CH3) performed the best for both direct and indirect modes and is therefore considered as the best candidate. The CH3 model will be implemented in the new version of Canoe Hydrobox (CH) platform. This study provides a basis for further research into hydrological models for SUDS and their hydraulic performance.

A Deterioration Model for Sewer Pipes Using CCTV and Artificial Intelligence

Sewer pipeline failures pose significant threats to the environment and public health. To tackle these repercussions, many deterioration models have been developed to predict the conditions of sewer pipes, most of which are based on CCTV inspection reports. However, these reports are prone to errors due to their subjective nature and human involvement. More importantly, there are insufficient data to develop prudent deterioration models. To address these shortcomings, this paper aims to develop a CCTV-based deterioration model for sewer pipes using Artificial Intelligence (AI). The AI-based model relies on the integration of an unsupervised, multilinear regression technique and Weibull analysis. Findings derived from the Weibull deterioration curve indicate that the useful service life for concrete and vitrified clay pipes are 79 years and 48 years, respectively. The regression models show that the R2 value for vitrified clay sewer pipes, concrete sewer pipes, and ductile iron sewer pipes are 71.18%, 71.47%, and 81.51%, respectively, and 73.69% for concrete stormwater pipes. To illustrate the impact of various factors on sewer pipes, sensitivity analyses under different scenarios are conducted. These analyses indicate that pipe diameter has a significant influence on sewer pipe deterioration, with little impact on stormwater pipes. These findings would guide decision makers in identifying critical pipes and taking necessary precautionary measures. Further, this provides a sound basis for prioritizing maintenance actions, which would pave the way for designing sustainable urban drainage systems for cities.

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.