Green Stormwater Infrastructure Research Articles

Assessing Watershed-Scale Stormwater Green Infrastructure Response to Climate Change in Clarksburg, Maryland

AbstractStormwater green infrastructure (GI) practices are implemented in urban watersheds to control stormwater runoff, reduce pollution, and adapt to climate change. This study evaluated the robu...

Urban stormwater characterization, control, and treatment

This review summarizes over 250 studies published in 2018 related to the characterization, control, and management of urban stormwater runoff. The review covers three broad themes: (a) quantity and quality characterization of stormwater, (b) control and treatment of stormwater runoff, and (c) implementation and assessment of watershed-scale green stormwater infrastructure (GSI). Each section provides an overview of the 2018 literature, common themes, and future work. Several themes emerged from the 2018 literature including exploration of contaminants of emerging concern within stormwater systems, characterization and incorporation of vegetation-driven dynamics in stormwater control measures, and the need for interdisciplinary perspectives on the implementation and assessment of GSI. PRACTITIONER POINTS: Over 250 studies were published in 2018 related to thecharacterization, control, and treatment of stormwater. Studies covergeneral stormwater characteristics, control and treatment systems, and watershed-scale assessments. Trends in 2018 include treatment trains, vegetation dynamics,and interdisciplinaryperspectives.

Preferences for green infrastructure and green stormwater infrastructure in urban landscapes: Differences between designers and laypeople

Many cities in the US have implemented Green Stormwater Infrastructure (GSI) to manage stormwater. Because several types of GSI are relatively new, we do not know how people perceive GSI or the extent to which they prefer various configurations of GSI. We also do not know the extent to which laypeople perceive GSI differently from designers. This lack of knowledge costs us: we risk creating GSI that people find unappealing, and if they do not like it, they may not want to spend time in or near it, they may not maintain it, and they may not reap health benefits from it. In this study, 497 laypeople and 117 designers provided preference ratings of 55 photographs of GSI. We used factor analysis to identify the categories of GSI that people perceive. We found that landscapes with any GSI are significantly more preferred than landscapes with no GSI, and that the messiness of GSI impacted preference. Designers’ preferences were similar to those of laypeople, except that designers had a greater dislike for images consisting of lawns and retention ponds compared to laypeople, and designers had a slightly greater preference for newer forms of GSI, such as green roofs and bio-retentions. Designers can use these results to create preferred landscapes that manage stormwater while promoting the wellbeing of the people they serve.

Eco-efficiency Model for Outdoor Environmental Design of the Mixed-use Real Estate Development in Bangkok, Thailand

Nowadays, the dramatically of urban land developments affect to various of environmental problems, especially in urban heat and the reduction of natural porosity surfaces, then increasing of outdoor temperature and surface water runoff problems. These problems relate to urban residents outdoor living, especially in the large mixed-use real estate developments in Bangkok; the capital city of Thailand. Therefore, the development concerned on mitigating such problems by applying the eco-efficiency modeling to use as a sustainable design guideline for the new project development. The term of eco-efficiency is defined as the ratio of improvement cost per unit of the environmental impacts. This study formulates the eco-efficiency model by using the change of construction cost of outdoor environmental and their impacts which refer to the Physiological Equivalent Temperature (PET) as indicator for thermal comfort index of humans and stormwater runoff. The cost is calculated by simple cost estimation technique. Meanwhile, the microclimate model ENVI-met BioMet (V4) was used for predicting the effect different design options on outdoor thermal comfort using PET, and the Stormwater Runoff Test (SRT) is also calculated by the academic Green Stormwater Infrastructure (GSI) for Autodesk Infraworks 360 software. The results present as the prediction function of the eco-efficiency of the outdoor environmental design. Research suggests that pervious paving materials are broadly capable of lowering temperatures and improving human thermal comfort, and when integrated with trees have potential to meet eco-efficiency objectives. Moreover, the models can be used as the useful guideline for outdoor environmental design to toward the eco-friendly for urban residents’ outdoor living of mixed-use real estate development in Bangkok, Thailand. KeywordsEco-efficiencyWater SensitiveOutdoor Thermal ComfortPhysiological Equivalent Temperature (PET)Stormwater RunoffSimulation

A systematic review of the human health and social well-being outcomes of green infrastructure for stormwater and flood management.

The increase in frequency and intensity of urban flooding is a global challenge. Flooding directly impacts residents of industrialized cities with aging combined sewer systems, as well as cities with less centralized infrastructure to manage stormwater, fecal sludge, and wastewater. Green infrastructure is growing in popularity as a sustainable strategy to mimic nature-based flood management. Although its technical performance has been extensively studied, little is known about the effects of green stormwater infrastructure on human health and social well-being. We conducted a multidisciplinary systematic review of peer-reviewed and gray literature on the effects of green infrastructure for stormwater and flood management on individuals', households', and communities' a) physical health; b) mental health; c) economic well-being; and d) flood resilience and social acceptance of green infrastructure. We systematically searched databases such as PubMed, Web of Science, and Scopus; the first 300 results in Google Scholar; and websites of key organizations including the United States Environmental Protection Agency. Study quality and strength of evidence was assessed for included studies, and descriptive data were extracted for a narrative summary. Out of 21,213 initial results, only 18 studies reported health or social well-being outcomes. Seven of these studies used primary data, and none allowed for causal inference. No studies connected green infrastructure for stormwater and flood management to mental or physical health outcomes. Thirteen studies were identified on economic outcomes, largely reporting a positive association between green infrastructure and property values. Five studies assessed changes in perceptions about green infrastructure, but with mixed results. Nearly half of all included studies were from Portland, Oregon. This global systematic review highlights the minimal evidence on human health and social well-being relating to green infrastructure for stormwater and flood management. To enable scale-up of this type of infrastructure to reduce flooding and improve ecological and human well-being, widespread acceptance of green infrastructure will be essential. Policymakers and planners need evidence on the full range of benefits from different contexts to enable financing and implementation of instfrastructure options, especially in highly urbanized, flood-prone settings around the world. Therefore, experts in social science, public health, and program evaluation must be integrated into interdisciplinary green infrastructure research to better relate infrastructure design to tangible human outcomes.

Towards the implementation of green stormwater infrastructure: perspectives from municipal managers in the Pacific Northwest

To mitigate the harmful effects of stormwater runoff, many cities in the United States are constructing green stormwater infrastructure (GSI), yet the varied perceptions of GSI by local municipal managers can make or break the implementation of GSI in any given city. We conducted a series of focus groups with municipal managers from two adjacent regions in the Pacific Northwest (US) – Portland, Oregon and Clark County, Washington – where many of the earliest and most extensive applications of urban GSI have occurred. We aimed to understand the extent to which municipal managers fundamentally differ in their considerations of GSI, even within one metropolitan region. Results indicate that Portland respondents were optimistic about GSI implementation emphasizing stakeholder buy-in and regulatory systems. Alternatively, in Clark County, an unfunded state mandate, public concern, and uncertainties about facility performance culminated in a cautionary approach to GSI. The variation in findings has many implications for implementing GSI.

Identifying Key Factors for Implementation and Maintenance of Green Stormwater Infrastructure

Construction and maintenance can have major implications on the long-term functioning of green stormwater infrastructure (GSI) facilities. The GSI facilities investigated were bioretention, permeable pavement, sand filters, infiltration trenches, and vegetated swales. This study first highlights the most important construction and maintenance items based on relevant studies and state stormwater manuals from the United States. Fairfax County, Virginia, was used as a case study to evaluate the County’s current stormwater program and illuminate common maintenance issues found for each GSI type. The data analysis showed that deficiencies found can vary between public and private facilities, depending most likely on site conditions and frequency of routine maintenance. Sediment accumulation was found to be the most common maintenance issue (27.8% of inspections), supporting the importance of adequate pretreatment and good housekeeping when implementing GSI. Current postconstruction inspections performed by the County were found to be failing to detect inadequacies in bioretention facilities due to improper construction. It is recommended that municipal separate storm sewer systems (MS4s) thoroughly record and track construction and postconstruction inspection items to improve the longevity of its facilities and better inform future decision making regarding GSI.

Permeable Pavement Systems: Technical Considerations

Permeable pavement systems are Green Stormwater Infrastructure practices that can reduce runoff while supporting vehicle and pedestrian traffic. This new 8-page document provides technical details of permeable pavement systems, such as application, system elements, design, installation, operation, maintenance, crediting, and costs, in order to inform planners, engineers, landscape architects, local government officials, and other professionals in the built environment about the considerations for implementing and maintaining permeable pavements. Written by E. Bean, M. Clark, and B. Larson, and published by the UF/IFAS Department of Agricultural and Biological Engineering, April 2019. https://edis.ifas.ufl.edu/ae530

Utilizing SWMM and GIS to identify total suspended solids hotspots to implement green infrastructure in Lucas County, OH

AbstractThis research demonstrates that modeling approaches can be used to identify priority areas to implement green stormwater infrastructure (GSI) resulting in improved water quality outcomes. The total suspended solids (TSS) washoff loading from watersheds in Lucas County, Ohio due the municipal separate storm sewer system (MS4) was reported based on 2015 rain data. The highest TSS loading was experienced in the winter season in 80% of the watersheds. Subcatchments with the highest predicted TSS washoff loadings were identified as priority areas or hotspots. In subsequent simulations, GSI implementation in hotspots improved water quality by more than twofold as compared to indiscriminate implementation of GSI. These hotspot maps are being used by regional stormwater stakeholders to focus their urban water quality efforts and to identify site characteristics that may be used to inform environmental policy.

Remediation of Stormwater Pollutants by Porous Asphalt Pavement

Porous Asphalt (PA) pavements are an increasingly adopted tool in the green stormwater infrastructure toolbox to manage stormwater in urbanized watersheds across the United States. This technology has seen particular interest in western Washington State, where permeable pavements are recognized as an approved best management practice per the National Pollutant Discharge Elimination System (NPDES) municipal stormwater permit. Stormwater effluent concentrations from six PA cells were compared with runoff concentrations from three standard impervious asphalt cells to quantify pollutant removal efficiencies by porous asphalt systems. Additionally, the effects of maintenance and pavement age on pollutant removal efficiencies were examined. Twelve natural and artificial storms were examined over a five-year period. Street dirt and pollutant spikes were added to the pavements prior to some storm events to simulate high loading conditions. Results from this work show that porous asphalt pavements are highly efficient at removing particulate pollutants, specifically coarse sediments (98.7%), total Pb ( 98.4%), total Zn (97.8%), and total suspended solids (93.4%). Dissolved metals and Polycyclic Aromatic Hydrocarbons (PAH) were not significantly removed. Removal efficiencies for total Pb, total Zn, motor oil, and diesel H. improved with the age of the system. Annual maintenance of the pavements with a regenerative air street sweeper did not yield significant pollutant removal efficiency differences between maintained and unmaintained PA cells.

Evaluating Green Stormwater Infrastructure strategies efficiencies in a rapidly urbanizing catchment using SWMM-based TOPSIS

The dramatic changes in Land-Use and Land-Cover (LULC) in urbanizing areas have led to problems such as urban flooding and water pollution. Green Stormwater Infrastructure (GSI) has become a new approach to mitigate these problems. The comprehensive assessment of GSI strategies and their combinations is the foundation for decision making regarding GSI implementation. Using the rapidly developing Western New City of Zhuhai in China as an example, this study applies Storm Water Management Model (SWMM) to evaluate Single and Combined GSI strategies. Four indicators—runoff volume control, peak flow reduction, pollutant removal, and economic cost—are selected to conduct a Multi-Criteria Decision Analysis with the use of Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS). The performance evaluation of Single and Combined GSIs suggests that: (i) there may exist linear or nonlinear relation between the efficiency of a Single GSI and the size of its implementation. (ii) the optimal LULC-cost effective range may be identified for certain GSI, and (iii) Distributed-Centralized Combined GSIs are superior to other strategies in regard to reduction of runoff, TSS and peak flow. The TOPSIS assessment indicates that the cost weight (wc) has significant impact on the multi-criteria decision-making, and all strategies may be classified into three categories: effectiveness, cost, and stability. The results of TOPSIS show that the Distributed-Centralized Combined GSIs (scenarios S3, S5) are the best options if wc is not an important factor, while the Centralized Single GSI (S6) is the best option if wc becomes more important. Furthermore, this study can provide the well-informed alternative stormwater management plans and GSI decisions for local planners and water resource managers in the rapidly urbanizing sponge cities.

Green Stormwater Infrastructure (GSI) for Stormwater Management in the City of Los Angeles: Avalon Green Alleys Network

Stormwater runoff creates flooding/pollution hazards in urban areas and Green Stormwater Infrastructure (GSI) provides modern technologies for prevention and mitigation. The Avalon Green Alley Network North and South GSI Demonstration Project (The GSIs) described in this article is a joint partnership between Los Angeles Sanitation (LASAN) and The Trust for Public Land (TPL). The GSIs is located in public alley right-of-way in a high-density neighborhood (residential, schools, parks, commercial building). The GSIs slows and infiltrates stormwater on site, capturing runoff from intersecting street catch basins, employing dry-well chambers, replacing impervious/conventional asphalt with permeable surfaces, percolating stormwater, and providing underground storage. The GSIs north section is closed to vehicular traffic after construction of a grassy swale to capture stormwater. Stormwater drains toward interlocking pavers and into underground infiltration trenches, with extra flows conveyed to a dry-well system. Monitoring includes groundwater monitoring wells, flow meters, and water-level loggers (measure water quality/quantity). Further benefits for the community includes of growing of vines/espalier trees, artistic paving, and mural artwork evoking artistic expression. The GSIs approach is setting a new trend for stormwater management in the City of Los Angeles in the untapped 1440 km of alleys, and serves as a model of community development through stormwater management to other cities.

Green Infrastructure and the Hidden Politics of Urban Stormwater Governance in a Postindustrial City

Infrastructure tells a material story of ongoing challenges in cities, reflecting the diverse, normative desires of different communities. In this article we examine the introduction of green infrastructure technologies into urban infrastructure systems to think critically about these challenges and desires. Green infrastructure is an intentionally designed, multifunctional technology that directly uses or mimics the ecological processes of soils and plants (e.g., green rooftops, rain gardens, and bioswales). Facing budget shortfalls as well as demands to mitigate hazards and green the city, urban leaders are looking at green infrastructure as a facility that can provide diverse cobenefits along with traditional services. A focus on stormwater-based metrics, however—effectively reframing green infrastructure as green stormwater infrastructure—discursively tamps down alternative politics and desires for the city. Through a case study of Pittsburgh’s stormwater governance, we argue that the work to (re)technologize green infrastructure as green stormwater infrastructure is an act of depoliticization that hinders needed conversations about just infrastructure outcomes. We draw on themes from qualitative interviews with community members engaged in urban water governance to suggest that these moments of transition provide an opportunity to illuminate previously obscured infrastructure politics and challenge the forms of knowledge that bind us to conventional routines of urban environmental governance. We see an opportunity to reframe the conversation in a way that opens up opportunities for historically disenfranchised communities to voice their needs beyond the technocratic problem of stormwater management.

Spatial analysis of landscape and sociodemographic factors associated with green stormwater infrastructure distribution in Baltimore, Maryland and Portland, Oregon

This study explores the spatial distribution of green stormwater infrastructure (GSI) relative to sociodemographic and landscape characteristics in Portland, OR, and Baltimore, MD, USA at census block group (CBG) and census tract scales. GSI density is clustered in Portland, while it is randomly distributed over space in Baltimore. Variables that exhibit relationships with GSI density are varied over space, as well as between cities. In Baltimore, GSI density is significantly associated with presence of green space (+), impervious surface coverage (+), and population density (−) at the CBG scale; though these relationships vary over space. At the census tract scale in Baltimore, a different combination of indicators explains GSI density, including elevation (+), population characteristics, and building characteristics. Spatial regression analysis in Portland indicates that GSI density at the CBG scale is associated with residents identifying as White (−) and well-draining hydrologic soil groups A and B (−). At both census tract and CBG scales, GSI density is associated with median income (−) and sewer pipe density (−). Hierarchical modelling of GSI density presents significant spatial dependence as well as group dependence implicit to Portland at the census tract scale. Significant results of this model retain income and sewer pipe density as explanatory variables, while introducing the relationship between GSI density and impervious surface coverage. Overall, this research offers decision-relevant information for urban resilience in multiple environments and could serve as a reminder for cities to consider who is inherently exposed to GSI benefits.

Integrating placemaking concepts into Green Stormwater Infrastructure design in the City of Philadelphia

Green Stormwater Infrastructure (GSI) is a sustainable way to manage urban stormwater. GSI projects are usually designed with little or no community involvement and provide mostly environmental and...

Engaging the Private Homeowner: Linking Climate Change and Green Stormwater Infrastructure

Current and projected climate change in the Minnesota Lake Superior Coastal Area indicates an increase in frequency and intensity of extreme rainfall. One key outcome of this change is a subsequent potential increase in stormwater runoff, a concern exacerbated by the region’s shallow, often clay soils and exposed bedrock, along with highly impervious urban surfaces. This situation, coupled with public perception of climate change that is increasingly inclusive of severe weather, highlights an opportunity to apply green infrastructure to the challenge of stormwater management, referred to as green stormwater infrastructure. In addition to coordinated public action at local, state, and national levels, there is a role for the private landowner to participate in this form of climate adaptation. Private citizens have an opportunity to both protect their home and property while contributing to overall stormwater management for the community in which they live. Focus group research was conducted to better understand outreach and involve local residents in the creation of a tool to assist private green stormwater infrastructure efforts. Results of the focus group sessions were analyzed, and key themes emerged from the data to guide this process and support private home/landowner action. It is recommended that a fifth domain be added to the typology for public and private roles in climate adaptation, i.e. private adaptation for public and private benefit.

A GIS-Based Framework Creating Green Stormwater Infrastructure Inventory Relevant to Surface Transportation Planning

The stormwater runoff that carries pollutants from the land adjacent to road transportation systems may impair the water environment and threaten the ecosystem and human health. A proper management approach like green stormwater infrastructure (GSI) can help control flooding and the runoff pollutants. One barrier for GSI analysis relevant to system-level surface transportation planning is the lack of the inventory of GSI in many U.S. cities. This study aims to develop a GIS-based framework for creating GSI inventory in a time and labor efficient way, different from the traditional survey-based method. The new proposed framework consists of three steps, including road categorization, GSI mapping, and GSI type identification using the GIS data, high-resolution land-cover image, and Google Earth street view pictures. The new approach was tested in Philadelphia, Pennsylvania and also applied in Tampa, Florida. The results showed that the new GIS-based framework can achieve similar accuracy to the survey-based method while saving time and labor. The GSI inventory created in the study demonstrated the usefulness of the proposed framework for analyzing the status of GSI implementation and identifying gaps for future planning in terms of potential locations and underrepresented GSI types.

Prioritizing Suitable Locations for Green Stormwater Infrastructure Based on Social Factors in Philadelphia

Municipalities across the United States are prioritizing green stormwater infrastructure (GSI) projects due to their potential to concurrently optimize the social, economic, and environmental benefits of the “triple bottom line”. While placement of these features is often based on biophysical variables regarding the natural and built environments, highly urbanized areas often exhibit either limited data or minimal variability in these characteristics. Using a case study of Philadelphia and building on previous work to prioritize GSI features in disadvantaged communities, this study addresses the dual concerns of the inequitable benefits of distribution and suitable site placement of GSI using a model to evaluate and integrate social variables to support decision making regarding GSI implementation. Results of this study indicate locations both suitable and optimal for the implementation of four types of GSI features: tree trenches, pervious pavement, rain gardens, and green roofs. Considerations of block-level site placement assets and liabilities are discussed, with recommendations for use of this analysis for future GSI programs.

Reliability-Based Approach to Investigating Long-Term Clogging in Green Stormwater Infrastructure

AbstractGreen stormwater infrastructure (GSI) is defined by the integration of natural processes into the built environment to provide important ecosystem services. While GSI has multiple benefits,...

Soil and microbial properties of green infrastructure stormwater management systems

Green infrastructure (GI) refers to environmental design features or engineered systems in an interconnected natural and urban space that provide multifunctional ecosystem services. However, there is great uncertainty and variation in the function of different GI features related to carbon and nitrogen cycling processes that are essential for sustained plant growth and water quality. The objective of this study was to evaluate the effects of GI designs (enhanced tree pits (ETP), street-side infiltration swales (SSIS), and vegetation swales (VS)), including surface area, and watershed area ratio (WAR), on the biogeochemical processes and properties (organic carbon (Corg), total nitrogen (Ntotal), pH, salts, total petroleum hydrocarbons (TPH), Pb, Zn, moisture content (MC), texture, microbial biomass carbon and nitrogen content, potential net nitrogen mineralization and nitrification, microbial respiration, and denitrification potential) of GI engineered soils. Results showed that GI sites did not have significant levels of contamination with metals or TPH and that GI with larger surface area had significantly lower TPH, Pb, and Zn. Microbial biomass and activity were positively correlated with Corg, Ntotal, pH, MC, TPH, and WAR. Denitrification potential was higher in the ETP and SSIS (3 mg N kg−1 h−1) compared to the VS (0.5 mg N kg−1 h−1). Microbial biomass carbon and nitrogen contents were significantly higher in ETP followed by SSIS then VS. These results suggest that relatively young (<10 years) GI sites provide significant levels of microbial biomass and activity that are important for carbon and nitrogen cycling.