Sustainable Stormwater Research Articles

Toward sustainable stormwater management: Understanding public appreciation and recognition of urban Low Impact Development (LID) in the San Francisco Bay Area

In the United States, regulators, planners, and designers have promoted Low Impact Development (LID) as a landscape-based approach to better manage urban stormwater for ecological benefits. However, the projects have often failed to achieve positive public responses due to their unattractive and unkempt appearances. This study provides empirical insights into public perception of urban LID practices by studying user reactions to 16 sites located in the San Francisco Bay Area—eight with LID design and eight with conventional landscape design. Most of the 502 respondents, although expressing some misconceptions and limited stormwater knowledge, showed their appreciation and recognition of the LID landscapes. This finding implies that the implementation of new LID facilities can be continued and expanded without serious concern about strong public resistance, and suggests that the design of these existing LID sites can serve as models for the future projects in the San Francisco Bay Area, along with other urban areas. The study confirms the important role of picturesque beauty, naturalness, and neatness in satisfying public expectations, especially for aesthetic and ecological landscapes. Interestingly, interpretive signs appeared to be the preferable means for motivating stormwater education and the powerful means for producing positive public reactions to LID sites, suggesting the potential of urban LID projects as the venues for public education and outreach. The study not only emphasizes the alignment of aesthetics and ecology to enhance public satisfaction, but also promotes the aesthetic qualities and didactic opportunities as the essential components of LID implementation.

Impact of antecedent dry-weather period and rainfall magnitude on the performance of low impact development practices in urban flooding and non-point pollution mitigation

The potential of low impact development (LID) practices in stormwater management has received increasing attention. However, the impacts of antecedent dry-weather periods (ADP) and rainfall magnitude on LID performance in the mitigation of urban flooding and non-point pollution remain largely unexplored. In this study, the LID performance under different ADP and rainfall patterns was investigated using a hybrid hydraulic and water quality modeling approach with consideration of uncertainty and sensitivity. The results showed that LID practices mitigated the runoff volume, peak flow, and non-point pollutant loads by a maximum of 57.16%, 52.46%, and 76.27%, respectively. An increase in the length of the ADP improved the LID performance by 43.98%–77.25%, while an increase in rainfall magnitude weakened the LID performance by 29.55%–73.43%. The uncertainty in the model caused a relatively greater impact on LID water quality performance than on LID hydraulic performance, and the uncertainty slightly increased with an increase in ADP length and rainfall magnitude. The ADP length had a positive impact on LID performance, and the rainfall magnitude had a negative impact on LID performance. In addition, the LID performance was heterogeneously distributed in space, and the spatial heterogeneity was exacerbated by both a decrease in ADP length and an increase in rainfall magnitude. The methods and findings presented in this study provide an additional reference for sustainable stormwater management by investigating the LID performance and influencing factors.

Storm Water Management

Over the past years, rapid growth due to urbanization and industrialization, the changes in Land over and land use patterns have resulted in permanent environmental pollution to the hydrological processes. The hydrological cycle in cities is seriously affected due to increasing impervious areas as a result of urban development which has enhanced the risk of urban flooding. The increase in the impermeable area decreases infiltration, increases the runoff and reduces the time of concentration. Hence, for a given amount of rainfall, greater flooding is generated. Understanding the scope and limitation of sustainable stormwater management techniques detailed literature review is carried out. Site suitability is based on spatial analysis of data like geomorphology, slope, recharge condition, landuse and Landover map. Then analyzing local site conditions possible techniques that could be used to manage stormwater runoff are recommended and conclusions are drawn on the same.

The Potential of Stormwater Management in Addressing the Urban Heat Island Effect: An Economic Valuation

Urban green infrastructure (UGI) within sustainable stormwater management provides numerous benefits to urban residents, including urban heat island (UHI) mitigation. Cost–benefit analyses (CBA) for UGI have been conducted at neighborhood level with a focus on stormwater management, but valuations of reductions in heat-related hospitalizations and mortality are lacking. These benefits create significant social value; the quantification thereof is essential for urban planning in providing a scientific foundation for the inclusion of UGI in UHI mitigation strategies. This study assesses the potential of three UGI scenarios developed for an urban neighborhood in Berlin, Germany. First, climate data analyses were conducted to determine the cooling effects of tree drains, facade greening, and green roofs. Second, a CBA was performed for each scenario to value UHI mitigation by estimating the damage costs avoided in reduced heat-related hospitalizations and fatalities, using the net present value (NPV) and benefit–cost ratio (BCR) as indicators of economic feasibility. The results indicate heat mitigation capabilities of all three UGI types, with tree drains achieving the strongest cooling effects. Regarding economic feasibility, all scenarios achieve positive NPVs and BCRs above one. The findings confirm the potential of stormwater management in mitigating UHI and generating substantial social value.

Sustainable stormwater management using rain gardens in urban areas

Stormwater runoff and combined sewer overflows in urban areas are the leading causes of flood and water quality degradation. Green infrastructures (GI) were introduced to treat stormwater runoff onsite to reduce these effects. A project was conducted in St. Louis, Missouri, US to assess the impact of installing one type of GIs (rain gardens) on the volume reduction of stormwater runoff from urban streets served by a combined sewer system. The rain gardens were installed in a six-block area between late 2013 to early 2014. After separating stormwater runoff flow from base flow in the sewer system, rain gardens efficiency was evaluated based on comparing the pre-installation condition in 2011/2012 and the post-installation condition in 2014. A reduction in the volume of stormwater runoff by installing the rain gardens was significant only at two sites. However, analysis was hampered by the high variability of the flow data and the difficulty in measuring flows in the sewers. For this type of field experiment, it is important to develop advanced flow measurement devices to overcome the problems of high variation in data and pay high attention to selecting the proper statistical tests to evaluate the stormwater runoff reduction.

A Monitoring and Control System for Stormwater Management of Urban Green Infrastructure

Urban green infrastructure (UGI) can be used as a sustainable stormwater management approach. UGI can bring numerous ecological benefits to cities, including increased urban resilience, increased availability of water resources, and optimization of habitats. This paper used empirical research methods to describe an Internet of things (IoT)-based UGI monitoring and control system for stormwater management (MCSSWM). Using a Xuzhou-based practical project in China as a case study, we introduce the construction process, method, and monitoring results of the system. The results showed that the MCSSWM could be beneficial for UGI ecological performance evaluation and management.

Addressing the adaptive challenges of alternative stormwater planning

ABSTRACT Municipal water sectors shift from building traditional grey stormwater infrastructure to ambitious plans for holistic blue–green infrastructure due to climate vulnerability. The shift requires new ways of thinking, working, and collaborating, and we need to understand and address the new planning challenges the shift creates. While existing stormwater literature explores a range of technical, institutional, and financial barriers to alternative stormwater implementation, we hold the shift requires a deeper understanding of holistic and flexible stormwater management approaches. In this context, we investigate adaptive challenges like norms, practices, uncertainty, and new ways of collaborating across sectors in alternative stormwater planning in Norway. The studied planning processes exemplify how the need for making stormwater measures legally binding in municipal planning changes work practices in municipal water sectors. A novelty of the paper is that it shows how water departments take leadership of formal planning processes and adopt the planning department's language and working methods. We find that the studied municipalities promote cross-sectoral collaborative approaches that create space for professional negotiation and mediation and invite a deeper understanding of other's interests and views. We hold that such approaches could contribute to more holistic and flexible planning approaches, securing long-term sustainable stormwater management.

A new analytical tool for a more deliberate implementation of Sustainable Drainage Systems

This paper presents a new analytical tool for a more deliberate qualitative assessment of and guidance for the way Sustainable Drainage Systems (SuDS) are governed and technically implemented. It is the result of a combination of concepts from various alternative “sustainability” approaches and provides for the first time a set of detailed but not exhaustive aspects and sub-aspects that are critical for holistic implementation. A wide range of topics relevant for the attainment of radical change are embraced that had been rarely simultaneously considered in practice and research until now. Analyses at neighbourhood level in the solarCity (Linz, Austria) and Monges-Croix du Sud (Cornebarrieu, France), where SuDS have been comprehensively deployed, demonstrate the suitability of the tool for the provision of a more holistic perspective and direction for further change. Both projects represent the accomplishment of important steps towards sustainable stormwater management, but wider perspectives are required if the positive effects achieved are to be extended. Efforts have been made to understand the bio-physical traits of place prior to design and subsequently fulfil some technical demands, but reticence remains to: a) explore “closer to nature” solutions and transformative social considerations, and b) enter a continuous cycle of co-evolution.

Rainwater Management in Urban Areas

Rising levels of impervious surfaces in densely populated cities and climate change-related weather extremes such as heavy rain events or long dry weather periods provide us with new challenges for sustainable stormwater management in urban areas. The Special Issue consists of nine articles and a review and focuses on a range of relevant issues: different aspects and findings of stormwater runoff quantity and quality, including strategies and techniques to mitigate the negative effects of such climate change impacts hydraulically, as well as lab-scale and long-term experience with pollutants from urban runoff and the efficiency of stormwater quality improvement devices (SQIDs) in removing them. Testing procedures and protocols for SQIDs are also considered. One paper analyses the clogging of porous media in the use of stormwater for managed aquifer recharge. The Special Issue demonstrates the importance and timeliness of the topic of sustainable rainwater management, especially with regard to growing cities and the challenges posed by climate change.

The Efficacy of Whole Oyster Shells for Removing Copper, Zinc, Chromium, and Cadmium Heavy Metal Ions from Stormwater

This research investigates the use of a common food waste product for removing four different types of metals typically found in stormwater. Whole, unprocessed oyster shells are explored for use in stormwater management infrastructure that addresses water quality concerns. The role of the shells’ surface area, exposure time, and the solution’s initial concentration on the removal efficiency were examined. Beaker scale experimental results demonstrated very good efficiency by the oyster shells for removing copper ions (80–95%), cadmium ions (50–90%), and zinc ions (30–80%) but the shells were not as effective in removing hexavalent chromium (20–60%). There was a positive relationship between initial concentration and removal efficiency for copper and zinc ions, a negative relationship for hexavalent chromium, and no relationship was found for cadmium ions. There was also a positive relationship between surface area and removal efficiency, and exposure time and removal efficiency. However, after a certain exposure time, the increase in removal efficiency was negligible and desorption was occasionally observed. A mid-scale experiment to mimic real-world conditions was conducted in which continuous inflow based on a 6-h design storm was applied to 2.7 kg of whole, unprocessed oyster shells. The shells provided an 86% and an 84% removal efficiency of cadmium and copper ions, respectively, in one day of hydraulic retention time. No removal was observed for hexavalent chromium, and zinc ion removal was only observed after initial leaching. This work has significant implications for sustainable stormwater infrastructure design using a material commonly found in municipal food waste.

Advanced Graphical–Analytical Method of Pipe Tank Design Integrated with Sensitivity Analysis for Sustainable Stormwater Management in Urbanized Catchments

Pipe tanks represent important runoff retention elements of urban stormwater systems. They enable us to reduce and retain runoff as well as to mitigate peak flows in the network. Pipe tanks are often taken into account while designing the spatial plan of urban catchment areas. Hence, there is a need to develop a relatively quick and accurate method for pipe tank dimensioning. A graphical–analytical method of designing a pipe tank is presented in the paper. In the assumed methodology, the possibility of employing machine learning for obtaining a more precise error prediction of the proposed pipe tank design method (compared with the tank volume simulations using the storm water management model (SWMM)) are considered. Thus far, this aspect has not been discussed in the literature. In the adopted calculation methodology, sensitivity analysis constitutes an important element, enabling us to assess the influence of the input data assumed for tank design on the dimensions of the outflow devices and the length of the retention chamber.

Sustainable stormwater management under the impact of climate change and urban densification

The demand for living space is rising in growing cities. To restrict urban expansion in the outskirts, a common strategy is to densify existing neighbourhoods. Densification implies the increase of water impervious area which increases the vulnerability to flooding during extreme precipitation events. Sustainable urban drainage systems are considered as a strategy to handle stormwater runoff locally and thus relieve the sewage system. This study investigates the combined quantitative hydrological impact of densification and sustainable stormwater management measures in a residential neighbourhood in Munich, Germany. The living-lab approach pursues the application of nature-based solutions in a real planning case to achieve positive climate effects while densifying the neighbourhood. The study is based on single event simulations of three return periods with the physically based software PCSWMM. The events are implemented for both current and climate change precipitation intensities of the RCP 8.5 projection for 2040–2069. Three scenarios are implemented: a status quo, a business as usual scenario (additional buildings without compensation measures) and a best-case scenario (one additional floor with green roofs disconnected from the sewers in combination with rain gardens and porous pavements on the land parcels). The comparison between the different scenarios focuses on three main aspects of the water balance, namely, infiltration, runoff and storage. The results show that measures for sustainable stormwater management are crucial elements to cope with an increasing number of heavy precipitation events due to climate change. The best-case scenario significantly outperforms the other two concerning water infiltration, surface runoff and storage. Most notably is the impact of climate change projection rainfall intensities for 2040–2069. The outcomes for these intensities clearly show the positive impact of sustainable water-sensitive design. The results demonstrate that it is in fact possible to enhance the water balance and gain new living space simultaneously if a sustainable urban planning strategy is implemented that includes future-oriented stormwater management.

Multiscale watershed landscape infrastructure: Integrated system design for sponge city development

Conventional centralized drainage systems are not only expensive, but their mono-function to discharge surface runoff also imposes a negative effect on the local environment while compounding regional watershed dysfunction. Sponge city initiative promoted by the Chinese government is a broader sustainable stormwater management concept that aims to use more nature-based solutions, reduce urban flooding and runoff pollution, and increase rainwater resource usage. As part of decentralized and cost-effective solutions, green infrastructure (GI) is considered in the Sponge City development across China. Although GI has been successfully implemented through a range of small-scale projects, the GI approach has not been adopted widely, which is because the GI approach is micro-scale techniques and the local government is skeptical about the efficiency of GI to mitigate stormwater on a large scale. Although some researchers have explored the effectiveness of GI to reduce stormwater in small catchments, only a limited number of studies have examined the efficacy of GI at the watershed scale. Moreover, there is lack of a system and cross-scale approach in sponge city practices. To understand the effect of GI on the watershed scale, this paper proposed a comprehensive approach using ArcGIS and SWMM platforms to study the spatial configuration and implementation of multi-scale stormwater management. The approach is to apply a three-step sequence of catchments, sub-catchments, and micro-catchments for the urban watershed through designing interconnected network of landscape infrastructure (LI) systems. The design scenarios and performance of LI system-based approach with different combinations and sizes of the sponge facilities were analyzed based on the Old Town district of Hefei City, China. This study demonstrated that the inherent capacity of the landscape can act as the conduit for multifunctional, flexible, localized, and synergistic infrastructural systems, in which cross watershed holds promise to decrease both runoff volumes and peak flows while providing ecosystem services, such as enhancing neighborhood aesthetics and cultural/health benefits through shared public green spaces. Thus, Sponge City Development here as green concepts and techniques for nature-based solutions enhances the function and value of green infrastructure with benefits of ecological, economic and social significances, which presents a new approach for sustainable city making.

Modeling a Bioretention Basin and Vegetated Swale with a Trapezoidal Cross Section using SWMM LID Controls

The Low Impact Development (LID) Control module is utilized in the United States Environmental Protection Agency’s Stormwater Management Model (USEPA SWMM) to predict the hydraulic performance of a variety of sustainable stormwater technologies. Data collected in 2019 from the monitoring of a pilot project in Montreal was used to verify the ability of the Bioretention LID Control (which assumes a rectangular cross-section) to accurately simulate outflow from a structure with a trapezoidal cross-section. Two types of LID facility were modeled: one releases captured inflow through a perforated underdrain below the soil layer (bioretention basin; BB); and the other is drained at the surface of the soil layer (vegetated swale; VS). Initially, the modeled LID structures were sized identically to the field surface areas. However, it was necessary to change their model representation to account for the non-rectangular shape of the soil layer. In addition, a sensitivity analysis was completed, and the most influential parameters were identified as the conductivity slope and seepage rate. Both the alteration of the LID structure representation and the parametric calibration greatly improved the simulated outflows from the vegetated swale resulting in an increase of the Nash–Sutcliffe efficiency (NSE) coefficient from −0.6 to 0.64 (NSE >0.5 is acceptable for hydrologic models according to the literature). The bioretention basin calibration did not prove as successful. The evaluated LID Control module presented better predictive capabilities for the basin with a simpler overall design (VS).

Determination of water quality in Universiti Malaysia Sabah (UMS), Kota Kinabalu: The effectiveness of stormwater management systems

Universiti Malaysia Sabah (UMS) campus in Kota Kinabalu consists of a large detention pond that stores the stormwater and limits the outflow rate into Likas' estuary. It is no doubt the detention pond has been designed per the Urban Stormwater Management Manual (USMM) requirement in terms of quantity control, however rapid development and changes in surrounding landscapes may affect the water quality. This study investigates the stormwater quality from the UMS detention pond and drainages within the campus. Water sampling was primarily taken during the dry period to justify worst-case scenarios without dilution from the rainfall season. Then the water quality parameters were tested using standard laboratory procedures mainly for Biochemical Oxygen Demand (BOD), Ammoniacal Nitrogen (AN), and Total Suspended Solids (TSS) with a minimum of a triplicate experimental run at the Environmental Laboratory, Faculty of Engineering, UMS. The determined water quality was compared with the National Water Quality Standards (NWQS) from the Department of Environment Malaysia. Overall the stormwater quality obtained for Dissolved Oxygen (DO), Chemical Oxygen Demand (COD), AN and pH is within Class II to III, which is slightly polluted. However, the TSS from ponds near to main road and construction areas exceeds Class IV, indicating polluted conditions. There is a slight increase for BOD and AN parameters when comparing samples between June 2020 (post-MCO) and January 2017, which was suspected briefly due to fertilizing work for the campus landscapes. Although the TSS value is low, the TSS volume would increase over a period, raising the temperature while reducing the DO concentration and endanger the aquatic species and the ecosystem. Hence, it is recommended for a future study to emphasize TSS value as it would contribute significantly in designing sustainable stormwater management, particularly for the stormwater treatment, such as when optimizing for the utilization of alternative filter media, which reduces the maintenance and increasing the lifespan of the system.

Assessment framework to select sustainable storm water management options for urban areas

Bhumi is published by the Town & Country Planning Research Institute of the University of Moratuwa, Sri Lanka and the La Trobe University, Australia.Bhumi serves a wide range of subject areas directly and indirectly related to Urban and Rural Planning, Economics, Development, Governance, Urban Management, Environmental Planning, Resource Management, Construction, Housing, Infrastructure, Urban Design, Politics, Technology etc.

Analysis of Alternatives for Sustainable Stormwater Management in Small Developments of Polish Urban Catchments

Sustainable stormwater management approaches in accordance with the EU Water Framework Directive (WFD) allow a source control to handle the quality and quantity of the runoff at local level or near the source. The most popular technologies applied in Europe are green roofs, porous pavements, retention basins and bioswales/raingardens. In this article, two of these solutions (retention tank with reuse, and rain garden, respectively), applied to single dwelling case studies in a suburban area in the Silesia Region (Poland), are illustrated and analyzed. The selected cases consider technical and economic aspects as the most important factors for decision on the selection of onsite stormwater management approach. Both systems have been operational for approximately two years. The retention tank proved a good solution, reducing stormwater overflows and allowing local water reuse for lawn irrigation; however, investment and maintenance costs in this case are relatively higher. The raingarden proved to work efficiently in this small scale implementation and implied much lower initial investment and costs. The economic sustainability of these interventions at single dwelling scale was analyzed, showing interesting returns, with outcome depending on the degree of possible water reuse (lower water bills) and availability of fiscal or fee incentives. Introduction of financial incentive schemes will encourage homeowners and developers to implement stormwater control solutions, allowing rapid amortization of investment costs with additional benefits to the community, such as reduced environmental impact of stormwater overflows and possible economies in the construction and management of stormwater systems.

Low impact development strategies for a low-income settlement: Balancing flood protection and life cycle costs in Brazil

Due to economic, environmental, and other wider social issues, implementing sustainable urban drainage systems in developing countries is particularly complex. This study aimed to assess the adoption of low impact development (LID) strategies for a low-income settlement in São Carlos, Brazil, with the additional challenges presented by high-density, small lots, and social-economic constraints. A life cycle cost (LCC) analysis was conducted along with hydrological modeling for three scenarios. The business-as-usual (BAU) scenario: typical urban design and conventional drainage system (CDS). The infiltration well (IW) scenario: typical urban design and CDS associated with lots disconnection with IWs. The LID scenario: infiltration devices (swales and swale-trenches) associated with urban changes to achieve 100 % of runoff source control. A sensitivity analysis was carried out considering variations in the maintenance routine. The LCC revealed that the IW scenario had the higher overall costs: 15 % higher than BAU, and 5–22 % than LID. However, when the scenarios were assessed using a performance-based unit (costs/locally managed stormwater volume), the perspective changed: the LID scenario costs were the lowest (271–507 USD/m³), and BAU were the highest (926–1487 USD/m³). This joint assessment is expected to better assist the decision-making processes for sustainable stormwater management, balancing flood protection and costs.

A Novel Multicriteria Decision Making Model for Sustainable Stormwater Management

Precipitation not absorbed by the soil or local vegetation and remain on the surface leading to stormwater can cause soil erosion, flooding, property damage, and overflow to wastewater treatment facilities. This paper introduces a novel multicriteria decision-making model to choose among various sustainable solutions that can help in managing stormwater. This model is intended to help decision-makers in handling stormwater through proper utilization of precipitation while ensuring public safety and adhering to runoff regulations. The model also aims to present sustainable technologies that can help in reducing harmful stormwater overflows. As a way of constructing and validating the model, precipitation and other relevant data from the North-Eastern region of the United States were used. The model can be altered though to suit other regions in the world. The model was further validated by seeking the opinion of a group of experts on its constructs. Statistical analysis identified high item-to-total correlations for model constructs and a model Cronbach’s alpha value of 0.84 leading to conclude that the model is valid. Yet, green solutions presented in this study and the developed model should be considered as a first step in determining sustainable stormwater solutions and further research in this area is needed.

Middle-Term Evolution of Efficiency in Permeable Pavements: A Real Case Study in a Mediterranean climate.

Sustainable Drainage Systems (SuDS) are solutions used to reduce the effects of soil sealing and to contribute to sustainable storm water management. In recent years, many projects have been implemented in Europe, the United States, and Australia, but most of them have either not been monitored at all or have only been monitored in the short-term, so there is little information on the evolution of efficiency and clogging. Experiences in the Mediterranean are even rarer, so the main purpose of this research is to provide information about the long-term behavior of one kind of SuDS, the permeable pavements, in the middle-term under Mediterranean climatic conditions. This work shows the results of a real project developed in southern Spain, which has been monitored for five years. The evolution of efficiency in permeable pavements and their relationship with saturation are analyzed and discussed in this research. These results will help to manage and maintain permeable pavements in areas with a Mediterranean climatology.