Search Results (45)

In cold climatic zones, highway transportation routes are significant contributors to sediment-accumulated chloride ions (Cl⁻). Bioswale projects are designed to slow and treat roadway runoff and thereby meter the release of salts, but bioswale function is compromised over time as sediments become saturated with pollutants. This two-year project sought to test innovative practices to improve the function of Illinois Tollway (hereafter, Tollway) bioswales by investigating the effect of biochar addition (20 T/ha) and invasive plant harvesting on: (1) invasive cattail (Typha) dominance, (2) bioswale sediment chloride retention, and (3) harvestable chloride ions associated with living-green Typha tissues across a two-year field study in northeastern Illinois. We found that a single 20 T/ha biochar application resulted in significant increases in Typha [Dry Mass (g/m²) and Stem Count (count/m²), p ≤ 0.05] and sediment chloride concentration (ppm) [p ≤ 0.05]. Harvest did not significantly influence Typha standing stocks (p > 0.05) but did lead to a significant increase in harvestable chloride associated with living-green Typha tissues over the two-year study. This research demonstrates that a single 20 T/ha biochar application coupled with harvest of aboveground Typha biomass is a pathway for scalable management strategies to remove chloride and invasive standing stocks. Full article

The development of urban areas and the proliferation of impervious surfaces have significantly altered natural hydrological cycles, resulting in an increase in stormwater runoff and substantial risks to groundwater quality. This review synthesizes current research on the transport mechanisms of stormwater contaminants, including toxic elements, nutrients, pathogens, and emerging pollutants such as microplastics and pharmaceuticals, into aquifers. This study analyzes the physicochemical and biological processes that affect pollutant mobility and retention in urban soils, emphasizing the vulnerability of groundwater systems, particularly in areas with permeable soils and shallow water tables. The article evaluates a range of green infrastructure (GI) and low-impact development (LID) strategies—including rain gardens, bioswales, infiltration basins, constructed wetlands, and urban forestry—to assess how effectively they can mitigate stormwater pollution and improve groundwater protection. Case studies from North America illustrate the practical implementation and performance of GI systems, emphasizing the importance of site-specific design, monitoring, and adaptive management. The review also discusses global policy frameworks and community engagement strategies that support sustainable stormwater management. Ultimately, it advocates for an integrated, multidisciplinary approach that combines engineering, ecological science, and public policy to safeguard groundwater resources in the face of climate variability and urban expansion. Full article

Over the past 30 years, the City of Portland, Oregon, USA, has emerged as a national leader in green stormwater infrastructure (GSI). The initial impetus for implementing sustainable stormwater infrastructure in Portland stemmed from concerns about flooding and water quality in the city’s two major rivers, the Columbia and the Willamette. Heavy rainfall often led to combined sewer overflows, significantly polluting these waterways. A partial solution was the construction of “The Big Pipe” project, a large-scale stormwater containment system designed to filter and regulate overflow. However, Portland has taken a more comprehensive and long-term approach by integrating sustainable stormwater management into urban planning. Over the past three decades, the city has successfully implemented GSI to mitigate these challenges. Low-impact development strategies, such as bioswales, green streets, and permeable surfaces, have been widely adopted in streetscapes, pathways, and parking areas, enhancing both environmental resilience and urban livability. This perspective highlights the history of the implementation of Portland’s GSI programs, current design and performance standards, and challenges and lessons learned throughout Portland’s recent history. Innovative approaches to managing runoff have not only improved stormwater control but also enhanced green spaces and contributed to the city’s overall climate resilience while addressing economic well-being and social equity. Portland’s success is a result of strong policy support, effective integration of green and gray infrastructure, and active community involvement. As climate change intensifies, cities need holistic, adaptive, and community-centered approaches to urban stormwater management. Portland’s experience offers valuable insights for cities seeking to expand their GSI amid growing concerns about climate resilience, equity, and aging infrastructure. Full article

Urbanization and the expansion of impervious surfaces have increased stormwater runoff volumes, altered runoff timing, and degraded water quality and aquatic ecosystems. Runoff from urban areas carries pollutants such as nitrogen, phosphorus, sediments, and heavy metals, which can adversely impact the physical characteristics of receiving waterbodies. Stormwater management programs aim to mitigate these effects using Best Management Practices (BMPs) to retain and treat stormwater on-site. However, in densely developed areas, space constraints and high costs often make traditional BMPs impractical. This study assessed the effectiveness of expanded shale, an engineered material, as a filtration medium in bioswales, a type of linear BMP commonly used in transportation infrastructure. Thirty scenarios were tested in a 16 ft (4.9 m) long plexiglass flume using expanded shale mixed with sandy clay soil. Due to the limited scope of this study, it focused on assessing the effectiveness of expanded shale in removing suspended sediments and reducing turbidity. Results showed that expanded shale achieved removal efficiencies ranging from 20% to 82% for total suspended solids (TSS) and −4% to 61% for turbidity under different conditions. It outperformed conventional filtration materials such as sand and gravel, requiring less channel length. Remarkably, even in a small-scale laboratory setting, expanded shale met the suspended sediment removal standard of 80%, demonstrating its potential as a highly effective filtration material alternative for urban stormwater management. Full article

The increasing pressure on urban systems and buildings in South Africa caused by rapid urbanization and climate change necessitates innovative approaches, including Nature-based Solutions (NbSs), to address environmental and societal challenges. As such, this study aimed to determine the dynamic role of NbSs in shaping the sustainability of South Africa’s built environment. Using a quantitative approach, the data were collected via a questionnaire survey, which targeted built environment professionals. Data analysis involved reliability testing, confirmatory factor analysis, and Spearman rank order correlation. The survey showed that green roofs, rainwater harvesting, cool roofing and pavements, as well as living walls, have received above-average attention in the country, while agricultural byproducts from concrete construction, bioswales, rain gardens, and algae-based materials are yet to be explored in the delivery of green buildings and sustainable urban areas. Overall, deploying NbSs promises positive environmental, societal, and economic impacts. The findings emphasize the need for stronger policies and regulations that promote the adoption of underutilized NbSs within the South African built environment. Theoretically, this study contributes to the existing discourse on sustainable development in South Africa. As the nation grapples with diverse environmental and social issues, this study becomes timely, as it provides crucial insights into how NbSs can address some of these challenges. Full article

Green stormwater infrastructure (GSI) is increasingly implemented worldwide to address stormwater issues while providing co-benefits such as habitat provision. However, research on public perceptions of GSI’s ecosystem benefits is limited, and barriers such as perception and maintenance hinder biodiversity promotion in GSI. Through an online survey (n = 781), we explored how residents in four Northeast US urban areas—Prince George’s County and Montgomery County, MD, New York City, and Philadelphia, PA—perceived the benefits and concerns regarding two types of bioswales (biodiverse and turf). Biodiverse swales feature various plants to promote biodiversity, whereas turf swales are primarily grass-covered. Our analyses included paired-samples t-tests, independent t-tests, one-way repeated measures ANOVA tests, and one-way ANOVA tests to compare perceptions across bioswale types, aspects of benefit/concern, and locations. Both bioswale types were recognized for enhancing green spaces and neighborhood aesthetics. Residents perceived greater environmental and social benefits from biodiverse swales than turf swales, particularly for habitat provision. While overall concerns for both bioswale types were low, potential issues like pest cultivation and the unappealing appearance of biodiverse swales remain significant barriers. Notably, implementing biodiverse swales alleviated initial concerns, especially about pests, suggesting familiarity can enhance acceptance. Location-specific differences in perception were observed, with New York City showing higher perceived benefits and concerns and Montgomery County exhibiting the lowest concerns. This variance is likely due to distinct urban environments, levels of environmental awareness, and demographic profiles. Full article

Increasing urbanization and the associated sealing of areas and the use of storm sewer systems for drainage not only increase the risk of flooding but also reduce water quality in streams into which stormwater is discharged. Green infrastructure (GI) measures are applied with the aim of managing this stormwater sustainably and reducing the associated risks. To this end, a quantitative–qualitative approach was developed to simulate GI—namely, rain gardens, bioretention cells, and vegetative bioswales—at the urban catchment scale. The findings highlight the potential of applying GI measures to managing stormwater more effectively in urban environments and mitigating its negative pollution-related impacts. For the housing estate analyzed, a simulated implementation of GI resulted in a reduction in pollution, measured as total nitrogen (N; 9–52%), nitrate-N (5–30%), total phosphorus (11–59%), chemical oxygen demand (8–46%), total suspended solids (13–73%), copper (12–64%), zinc (Zn; 16–87%), polycyclic aromatic hydrocarbons (16–91%), and the hydrocarbon oil index (HOI; 15–85%). Reducing the concentrations of pollutants minimizes the risk to human health determined via the HOI from a low-risk level to zero risk and reduces the ecological risk in terms of Zn pollution from a significant risk to a low risk of adverse effects. The modeling conducted clearly shows that the GI solutions implemented facilitated a quantitative reduction and a qualitative improvement in stormwater, which is crucial from an environmental perspective and ensures a sustainable approach to stormwater management. Lowering the levels of stormwater pollution through the implementation of GI will consequently lower the environmental burden of pollutants in urban areas. Full article

Urban nature-based solutions (NBSs) are widely implemented to collect, store, and infiltrate stormwater. This study addressed infiltration rate as a measure of the performance of bioretention solutions. Quick scan research was conducted, starting with mapping over 25 locations of implemented green infrastructure in Riga, Latvia. Basic information, such as location, characteristics, as well as photos and videos, has been uploaded to the open-source database ClimateScan. From this, eight bioswales installed in the period 2017–2022 were selected for hydraulic testing, measuring the infiltration capacity of bio-retention solutions. The results show a high temporal and spatial variation of infiltration rate for the bioswales, even those developed with similar designs: 0.1 to 7.7 m/d, mean 2.0 m/d, coefficient of variation 1.0. The infiltration capacity decreased after saturation: a 30% to 58% decrease in infiltration rate after refilling storage volume. The variation in infiltration rate as well as infiltration rate decrease on saturation is similar to other full-scale studies done internationally. The infiltration rate of most bioswales falls within the range specified by international guidelines, all swales empty within 48 h. Most bioswales empty several times within one day, questioning the effectiveness of water retention and water availability for dry periods. The results are of importance for stakeholders involved in the implementation of NBS and will be used to set up Latvian guidelines for design, construction, and maintenance. Full article

Processes driving nutrient retention in stormwater green infrastructure (SGI) are not well quantified in water-limited biomes. We examined the role of plant diversity and physiochemistry as drivers of microbial community physiology and soil N dynamics post precipitation pulses in a semi-arid region experiencing drought. We conducted our study in bioswales receiving experimental water additions and a montane meadow intercepting natural rainfall. Pulses of water generally elevated soil moisture and pH, stimulated ecoenzyme activity (EEA), and increased the concentration of organic matter, proteins, and N pools in both bioswale and meadow soils. Microbial community growth was static, and N assimilation into biomass was limited across pulse events. Unvegetated plots had greater soil moisture than vegetated plots at the bioswale site, yet we detected no clear effect of plant diversity on microbial C:N ratios, EEAs, organic matter content, and N pools. Differences in soil N concentrations in bioswales and the meadow were most directly correlated to changes in organic matter content mediated by ecoenzyme expression and the balance of C, N, and P resources available to microbial communities. Our results add to growing evidence that SGI ecological function is largely comparable to neighboring natural vegetated systems, particularly when soil media and water availability are similar. Full article

The expansion of urban centers and peri-urban zones significantly impacts both the natural world and human well-being, leading to issues such as increased air pollution, the formation of urban heat islands, and challenges in water management. The concept of multifunctional greening serves as a cornerstone, emphasizing the interconnectedness of ecological, social, and health-related factors. This study aimed to identify potential locations for three specific types of blue-green infrastructure (BGI): bioswales, infiltration trenches, and green bus stops. Leveraging geospatial datasets, Geographic Information System (GIS) technology, and remote sensing methodologies, this study conducted a comprehensive analysis and modeling of spatial information. Initial cartographic representations were developed to identify specific locations within Olsztyn, a city in Poland, deemed appropriate for the implementation of the designated blue-green infrastructure (BGI) components. Following this, these models were combined with two additional models created by the researchers: a surface urban heat island (SUHI) model and a demographic model that outlined the age structure of the city’s population. This synergistic approach resulted in the development of a detailed map, which identified potential locations for the implementation of blue-green infrastructure. This was achieved by utilizing vector data acquired with a precision of 1 m. The high level of detail on the map allows for an extremely accurate representation of geographical features and infrastructure layouts, which are essential for precise planning and implementation. This infrastructure is identified as a key strategy for strengthening ecosystem resilience, improving urban livability, and promoting public health and well-being. Full article

High population growth, a lack of wastewater treatment plants and poor wastewater management are major challenges in wastewater management in Timor-Leste (East Timor). One of the approaches of the government of Timor-Leste is to separate wastewater into greywater and blackwater from domestic, commercial, residential, and industrial areas. Three methods were applied to obtain insight into the locations and discharge of grey- and blackwater to develop a cost-effective wastewater strategy: a field survey and data collection, interviews with over 130 participants from local authorities and communities, and the open-source mapping of locations of wastewater discharge. This research concluded that 47.7% of the grey wastewater is discharged into open sewers connected directly to the sea. Most communities discharge their wastewater directly due to the absence of wastewater management, policies and regulations, and lack of communities’ understanding of the possible health impacts of wastewater. The impact of poor wastewater management showed that most of the children in these communities have suffered from diarrhea (73.8%), and in the rainy season, there is a high possibility of infection with waterborne diseases. The literature review, field mapping, and interviews show that there is high demand for a cost-effective wastewater strategy for health improvement. Low-cost nature-based solutions such as constructed wetlands and bioswales can be implemented with local skills and materials to improve the wastewater situation and address other challenges such as biodiversity loss, heat stress, drought, and floodings. These installations are easier to rebuild than large-scale grey infrastructure given the multiple hazards that occur in Timor-Leste: landslides, earthquakes, strong wind, and pluvial and fluvial floodings, and they can serve as coastal protection. Full article

Sustainable urban drainage systems (SuDS) or nature-based solutions (NBSs) are widely implemented to collect, store and infiltrate stormwater. The buildup of pollutants is expected in NBSs, and Dutch guidelines advise monitoring the topsoil of bio-swales every 5 years. In the Netherlands, almost every municipality has implemented bio-swales. Some municipalities have over 300 bio-swales, and monitoring all their NBSs is challenging due to cost and capacity. In this study, 20 locations where bio-swales with ages ranging between 10 and 20 years old were selected for a field investigation to answer the following question: is the soil quality of bio-swales after 10 years still acceptable? Portable XRF instruments were used to detect potential toxic elements (PTEs) for in situ measurements. The results showed that for copper (Cu), zinc (Zn) and lead (Pb), 30%, 40% and 25% of the locations show values above the threshold and 5%, 20% and 0% above the intervention threshold, meaning immediate action should be taken. The results are of importance for stakeholders in (inter)national cities that implement, maintain, and monitor NBS. Knowledge of stormwater and soil quality related to long-term health risks from NBS enables urban planners to implement the most appropriate stormwater management strategies. With these research results, the Dutch guidelines for design, construction, and maintenance can be updated, and stakeholders are reminded that the monitoring of green infrastructure should be planned and executed every 5 years. Full article

Green Infrastructure (GI) is rooted in ecology and cuts across multiple disciplines, including landscape architecture, environmental sciences, planning, policy, and engineering. Likewise, the definition of this concept also cuts across disciplines, which creates ambiguity around what GI is and what makes up GI in practice—for example, mistaking bioswales for regular tree planters or green space within communities in which they are installed. We undertook a systematic literature review of 38 peer-reviewed articles for this study using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) method to identify and synthesize the different disciplinary definitions of GI in the literature. This study also presents the types of GI systems mentioned in the peer-reviewed articles while identifying other benefits apart from the primary benefit of GI installation, which is stormwater management. The analysis revealed three clusters of GI definitions: (I) Interconnected natural areas and other open spaces, (II) Strategically planned natural and semi-natural areas, and (III) Decentralized systems and techniques. However, we got rid of the third cluster during the analysis because GI is known to be a decentralized system, and the definition region could not be tracked. These clusters represent a spectrum, one of which employs the structure of natural systems already in place to support human goals (bio-inclusivity). The other includes living systems as components within engineered solutions to achieve objectives (bio-integration). This review points to the need for an encompassing definition that cuts across disciplines with a consensus on the adoption and concise categorization of GI types and the multiple benefits they provide to humans and ecosystems. A consensus definition helps clear misconceptions and improve the understanding of GI, potentially improving receptivity towards these solutions within communities from a community member perspective. Full article

Bio-swales have gained significant attention as an effective means of stormwater management in urban areas, reducing the burden on conventional rainwater management systems. Despite this increasing interest, a comprehensive assessment of the status of bio-swale research is lacking. In response, this article employs two powerful information-visualizing software tools, the “Bibliometrix” R package and “CiteSpace”, to conduct a quantitative investigation of 323 English language sources published in the Web of Science prior to 2022. The objective is to provide a comprehensive examination of bio-swale research from multiple perspectives, shedding light on current advancements and future research trends. The findings reveal (1) a persistent annual increase in bio-swale-related publications and (2) the predominant focus on regulating services, such as hydrology, water quality, and biodiversity, with hot topics within these areas, including the influencing factors, climate, modeling, soil contaminants, and biodiversity at both macro and micro levels. Furthermore, our study concludes that future research necessitates interdisciplinary and interterritorial collaboration, a broader focus that encompasses the social, economic, ecological, and engineering aspects of bio-swales, and the adoption of diverse research methodologies. Given the currently limited research on biodiversity in bio-swales, this area holds the potential to become a future research hotspot. By harnessing the insights and findings of our study, researchers can gain a more profound understanding of the current state of bio-swale research and devise effective strategies to further propel this critical area of study. Full article

With the aim of being a part of global change and providing an example to other researchers throughout the world, this paper details how breeding goals of horticultural plants and their application have shifted in Novi Sad (Serbia) in the last 10–15 years. Contemporary cities/citizens strive to incorporate nature into all of their important life segments and activities, thus requiring an interdisciplinary approach to solving challenges that the 21st century brings. Early research in Novi Sad (Serbia) was focused on the basic genetic, physiological, biochemical and botanical aspects of plant functioning and development in a challenging and changing urban environment abundant in abiotic stressors, as well as biotic and abiotic stressors, that affect the production of horticultural plant in this field. Recently, research interest has shifted towards the sustainable usage of plant genetic resources (roses, autochthonous terrestrial orchids, sweet and sour cherry eco-types, and allochthonous oil-rich species), as well as sustainable practices and nature-based solutions (urban-derived biodiesel, rain gardens, green roofs, green walls, constructed wetlands, water ponds, bioswales and permeable surfaces on a different scale of urban planning). This case study aimed to illustrate how plant selection and breeding strategies can satisfy urban growth demands, whereas urban planning must include sustainable genetic resources suitable for urban ecosystems. Available ornamental plant genetic resources (with pronounced tolerance/resistance to abiotic and/or biotic stressors) associated with the novel approach of their application in green city infrastructure provide the opportunity to implement multiple nature-based solutions leading to numerous ecosystem services. Combined, these contribute to the globally defined goals for sustainable development. Full article