A SUDS Planning Decision Support Tool to Maximize Ecosystem Services

How can we make sustainable urban drainage systems (SUDS) smart? SUDS help us to manage surface water runoff from urban environments but they are capable of delivering much more. This paper looks beyond the water quantity and quality improvement functions of SUDS and investigates the multiple benefits that can be gained by implementing smart SUDS solutions. This work provides a new perspective, using methodologies not normally associated with SUDS research, to determine multiple benefits. The outputs of the work can potentially assist decision-makers, designer and planners in recognising the potential for multiple benefits that can be delivered by SUDS. The ecosystem services (ES) associated with a large redevelopment in Dundee, Scotland, UK, are identified and a public perception study together with public participatory geographical information system (PPGIS) methods was used to confirm the goods and benefits of the SUDS. The paper presents findings on the public perception of SUDS as they provide cultural benefits such as recreation, aesthetics and biodiversity. The results show that greenspace is important when choosing a location, and willingness to pay for greenspace is high in this area. This paper concludes that SUDS provide multi-functional benefits in relation to the ES, thereby justifying the cachet of being termed Smart SUDS.

Despite being widely implemented, sustainable urban drainage systems (SUDS) do not always function flawlessly. While SUDS have been tested extensively and seem to perform well on a laboratory or pilot scale, practitioners' experience is different: failures in SUDS occur regularly in practice, resulting in malfunctioning systems, water nuisance and high costs. To anticipate their malfunctioning, and thus to improve their performance, a better understanding of failures occurring in SUDS and their underlying causes is needed. Based on an explorative case-study approach, consisting of site visits and semi-structured interviews with urban water professionals, this study presents an inventory of technical failures in SUDS and an analysis of their root causes. In total, 70 cases in 11 Dutch municipalities have been documented. The results show that the interfaces between SUDS and other urban systems are prominent failure locations. In addition, we found that failures originate from the entire development process of SUDS, i.e., from the design, construction and user/maintenance phase. With respect to the causes underlying these failures, our results show that these are mainly socio-institutional in nature. These are valuable insights for both practitioners and scholars, contributing to a renewed socio-technical urban water system with more sustainable water management practices.

The use of decentralised, sustainable urban drainage systems (SUDS) for the treatment of stormwater runoff is becoming increasingly prevalent in Germany. Decentralised SUDS can offer a viable and attractive alternative to end of pipe treatment systems for stormwater runoff from urban areas. However, there is still some uncertainty regarding the long-term performance of SUDS, and the general legislative requirements for SUDS approval and testing. Whilst the allowable pollution levels in stormwater runoff that infiltrate into ground and/or water table are regulated across Germany by the Federal Soil Protection Law, there is presently no federal law addressing the discharge requirements for surface water runoff. The lack of clear guidance can make it difficult for planners and designers to implement these innovative and sustainable stormwater treatment systems. This study clarifies the current understanding of urban stormwater treatment requirements and new technical approval guidelines for decentralised SUDS devices in Germany. The study findings should assist researchers, designers and asset managers to better anticipate and understand the performance, effective life-spans, and the planning and maintenance requirements for decentralised SUDS systems. This should help promote even greater use of these systems in the future.

Sustainable urban drainage systems (SUDS), or urban green infrastructure for stormwater control, emerged for more sustainable management of runoff in cities and provide other benefits such as urban mitigation and adaptation to climate change. Research in Spain began a little over twenty years ago, which was later than in other European countries, and it began in a heterogeneous way, both in the SUDS typology and spatially within the peninsular geography. The main objective of this work has been to know through bibliographic review the state of the art of scientific research of these systems and their relationship with the different types of climates in the country. These structures have a complex and sensitive dependence on the climate, which in the Iberian Peninsula is mostly type B and C (according to the Köppen classification). This means little water availability for the vegetation of some SUDS, which can affect the performance of the technique. To date, for this work, research has focused mainly on green roofs, their capabilities as a sustainable construction tool, and the performance of different plant species used in these systems in arid climates. The next technique with the most real cases analyzed is permeable pavements in temperate climates, proving to be effective in reducing flows and runoff volumes. Other specific investigations have focused on the economic feasibility of installing rainwater harvesting systems for the laundry and the hydraulic performance of retention systems located specifically in the northeast of the Iberian Peninsula. On the contrary, few scientific articles have appeared that describe other SUDS with vegetation such as bioretention systems or green ditches, which are characteristic of sustainable cities, on which the weather can be a very limiting factor for their development.

Urbanisation has led to numerous challenges in terms of stormwater management and environmental impact. Sustainable Urban Drainage Systems (SUDS) have emerged as a promising approach to mitigate these challenges by mimicking natural processes and providing environmentally sound water disposal systems. This review paper provides a comprehensive overview of the status of SUDS on a global scale, focusing on their development, challenges, and environmental benefits. This review paper discusses various SUDS techniques, including permeable paving, green infrastructure, and detention ponds, and highlights their effectiveness in reducing stormwater runoff, improving water quality, and enhancing ecological services. The paper also identifies the challenges faced in implementing SUDS, including technical complexity, lack of common platforms for SUDS models, limited operational experience, and institutional barriers. Additionally, the paper presents potential solutions to overcome these challenges, such as promoting research and development, providing training and capacity-building programs, and establishing guidelines and standards for SUDS design. The findings and recommendations presented in this paper contribute to the development of sustainable urban environments and the enhancement of overall environmental conditions.

Urban runoff frequently carries elevated concentrations of heavy metals such as nickel (Ni), posing significant environmental and public-health risks. Sustainable Urban Drainage Systems (SUDS) offer a promising pathway to mitigate these impacts, particularly through the use of filter media that enhance water decontamination. This study evaluates Filtralite, a lightweight expanded clay aggregate, as a filtration medium for Ni removal, with special emphasis on the evolution of pH under prolonged operational conditions and on the influence of particle size on the material’s treatment capacity.The research was based on an 80-day experiment designed to simulate an accelerated weathering process similar to what occurs under real operating conditions when SUDS interact with rainfall. Four granulometric fractions (2 mm, 1 mm, 0.5 mm, and 0.25 mm) were tested under controlled, repeated washing cycles carried out statically: the Filtralite was kept submerged in beakers, and its water was replaced on an approximately daily basis throughout the 80-day period. The pH values of the effluent were systematically recorded and interpreted as a proxy for the material’s alkalinity-generating capacity—an essential driver of Ni removal from the contaminated solution.Results demonstrate a consistent granulometry-dependent pattern in pH evolution. Coarser fractions (2 and 1 mm) experienced a more rapid decline in alkalinity than finer ones: although initial effluent pH values exceeded 10, they dropped below the threshold required for efficient Ni precipitation (≈8.5–9) after only a few litres of cumulative washing. The 2 mm fraction dropped to pH 8–8.5 after approximately 8–10 L of equivalent runoff, suggesting a short effective lifespan in real SUDS applications. The 1 mm fraction exhibited a slower decline, maintaining pH > 9 for a longer period, but ultimately converging toward circumneutral values at extended washing volumes. In contrast, finer fractions (0.5 and 0.25 mm) preserved alkaline conditions throughout most of the experiment. The 0.5 mm material sustained pH values in the range 9–10 for the majority of the test, indicating a more stable and gradual release of alkaline species. The finest fraction (0.25 mm) provided the most robust performance: effluent pH consistently remained between 9.5 and 10 even under high cumulative washing volumes, reflecting the strong buffering capacity associated with its larger specific surface area.Overall, the findings confirm that Filtralite is an effective and sustainable medium for Ni removal in SUDS, although its long-term performance is highly sensitive to granulometry. Fine fractions provide a prolonged alkaline environment that enhances precipitation-driven removal. These results suggest that finer Filtralite may offer favourable characteristics for potential field applications, supporting more stable and efficient metal removal over extended periods. However, the reduced particle size also implies lower hydraulic conductivity compared to coarser fractions, which could limit infiltration performance in practical implementations. Validation under real operating conditions is therefore still required.

Nature-based Solution (NBS) is an umbrella for ecosystem-based approaches to prevent or mitigate the impacts of hydro-meteorological hazards. The increasing hydro-meteorological disaster occurrence such as floods in Bandung City because of both climate change phenomenon and rapid growth of Bandung City has caused a big impact on people live in slums and high-density settlement. Realizing this risk, Bandung City has implemented strategies to reduce flood risk, including the Sustainable Urban Drainage System (SUDS) as stated on the Bandung City Spatial Plan (RTRW) 2011-2031. However, this measure had not effectively reduced flood risk in Bandung City. Therefore, this research focuses to analyse the implementation of SUDS and how it can capture the concept of NBS, with the study case Cibadak Administrative Village, one of the poor and high-density urban settlements in Bandung City. The result was developed using a mixed method consisting of a descriptive quantitative approach, spatial analysis for satellite imagery, and content analysis technique to analyse each challenge of SUDS implementation. The result indicates the lack of capacity in scale, budget, natural characteristic, and social demographic for SUDS implementation in poor and high-density urban settlement in Bandung, which aligns with the challenge of NBS implementation in the global south.

Climate change is pervasive, bringing about heat and floods. To address these hazards, better coping, adaptation and resilience are needed. Cities all over the world suffer from heat and flood disasters that account for significant losses. This paper examines the incidence of heat and flood occurrence in urban areas, and examines how sustainable urban drainage systems (SUDS) is used to combat them. The methodology is based on historical event analysis, literature review and secondary data. Results indicate that heat and flood hazards in cities can be effectively reduced by using SUD systems which incorporate vegetated surfaces that absorbs and retains rain water, purifies stormwater and transfers heat. Results show that SUD system reduces flood peaks and heat, thereby reducing the incidence of flash floods and heat islands. SUD system is recommended as a viable method of heat and flood control in cities as cities using SUDS were found to cope very well with heat and floods. Overall, technical measures of flood management such as SUDS are found to be effective, affordable, aesthetically pleasing and socially acceptable. A holistic strategy combing technical SUDSs and non-technical human aspects of coping and resilience is the key towards effective management of floods in cities.

4 - Biochar for sustainable drainage system

Many urban water quality and flooding problems may potentially be addressed by disconnecting stormwater from the formal drainage system and installing source control sustainable drainage systems (SuDS) instead. This approach is referred to as SuDS retrofit. This paper focuses on the construction costs associated with a range of SuDS devices likely to be implemented in a retrofit context. Three distinct types of costs have been prepared. The costs of construction per device are provided as unit costs. This approach does not, however, enable devices to be compared in terms of an area served. For this reason, schemes have been designed and costed according to representative contributory areas, such as a residential roof or a small car park. These contributory area-based cost comparisons are embodied within a decision-making framework for retrofit SuDS. A case study highlights how secondary costs need to be combined with device unit costs accurately to cost the construction of a whole scheme. The evaluation indicates that infiltration basins represent the cheapest form of SuDS to construct, followed by soakaways, ponds, infiltration trenches and porous pavements. This ranking does not, however, take account of land purchase or sterilisation costs, potential conflicts with requirements for high-density developments or other life-cycle costs—these could alter this preference ranking significantly.

The drainage system in the Kedungmundu Road area has several channels that can no longer accommodate the rainwater discharge, resulting in runoff of rainwater in the drainage channel, which causes flooding and puddles of rainwater in the Kedungmundu Road Area. Drainage in the Kedungmundu Road area has problems such as silting channels due to garbage, soil sedimentation, and insufficient channel dimensions. In the hydrological analysis, the rainfall intensity is 129,586 mm/hour. As the hydraulic analysis, the drainage channel is normalised by dredging sediment in the channel. If there is still rainwater runoff, additional channel dimensions are carried out, taking into account the existing conditions that only Karanggawang Lama road, H. Abdurochman road, and Kedungmundu Lama road changed. Channel dimensions, while for other channels, it is not possible to change the channel dimensions for that, it is necessary to apply SUDS. The Sustainable Urban Drainage System, or in SWMM 5.1 called Low Impact Development, is carried out using rainwater harvesting (Rain Barrel) and Permeable Pavement. The recapitulation of the application of the LID concept in the planning area is known to cover an area of 8.3 hectares of the total planning area of 54.48 hectares. This LID concept can reduce the total runoff value in each sub-catchment, thereby reducing the amount of rainwater discharge that enters the drainage channel with a percentage decrease in the average total runoff value of 19%. The Budget Plan needed to rehabilitate canals and dredging sediments and implement the Sustainable Urban Drainage System (SUDS) is around IDR 5,405,300,000.

Sustainable drainage systems (SuDS) design is predominantly based on expert opinion supported by descriptive guidance documents. The aim of this paper is to compare the novel Capacity Down Pipe SuDS technique in terms of its design, operation, maintenance, management and cost efficiency with other SuDS techniques. The assessment criteria are based on novel ecosystem service variables including those characterising flood and diffuse pollution control for fitting and retrofitting of key SuDS techniques particularly for the domestic housing market. The paper proposes the application of SuDS techniques that obtain high ecosystem service scores for a specific urban site. This approach contrasts with methods based on traditional civil engineering judgment linked to standard variables based on community and environment studies. For a case study area (Greater Manchester), a comparison with the traditional approach of determining community and environment variables indicates that soakaways and infiltration trenches are generally less preferred than capacity down pipes, ponds and filter strips. However, belowground storage tanks, swales and permeable pavements also received relatively high scores, because of their great potential impact in terms of flood volume control. The application of the proposed methodology will lead to changes of the sustainable drainage infrastructure in the urban landscape by promoting the novel capacity down pipe technology, which has a very low footprint and is inexpensive.

Origins and fate of polycyclic aromatic hydrocarbons (PAHs) in sustainable drainage systems (SuDS) in a Scottish urban area: Implications for groundwater systems.

Sustainable drainage systems (SUDS) offer many benefits that traditional solutions do not. Traditional approaches are unable to offer a solution to problems of flood management and water quality. Holistic consideration of the wide range of benefits from SUDS can result in advantages such as improved flood resilience and water quality enhancement through consideration of diffuse pollution sources. Using a geographical information system (GIS) approach, diffuse pollutant sources and opportunities for SUDS are easily identified. Consideration of potential SUDS locations results in source, site and regional controls, leading to improved water quality (to meet Water Framework Directive targets). The paper will discuss two different applications of the tool, the first of which is where the pollutant of interest is known. In this case the outputs of the tool highlight and isolate the areas contributing the pollutants and suggest the adequate SUDS measures to meet the required criteria. The second application is where the tool identifies likely pollutants at a receiving location, and SUDS measures are proposed to reduce pollution with assessed efficiencies.

Chapter 31 - Sustainable drainage system model