Increasing Sustainability of Residential Areas Using Rain Gardens to Improve Pollutant Capture, Biodiversity and Ecosystem Resilience

Abstract

Rain gardens have become a widespread stormwater practice in the United States, and their use is poised to continue expanding as they are an aesthetically pleasing way to improve the quality of stormwater runoff. The terms rain garden and bioretention, are now often used interchangeably to denote a landscape area that treats stormwater runoff. Rain gardens are an effective, attractive, and sustainable stormwater management solution for residential areas and urban green spaces. They can restore the hydrologic function of urban landscapes and capture stormwater runoff pollutants, such as phosphorus (P), a main pollutant in urban cities and residential neighborhoods. Although design considerations such as size, substrate depth, substrate type, and stormwater holding time have been rigorously tested, little research has been conducted on the living portion of rain gardens. This paper reviews two studies—one that evaluated the effects of flooding and drought tolerance on the physiological responses of native plant species recommended for use in rain gardens, and another that evaluated P removal in monoculture and polyculture rain garden plantings. In the second study, plants and substrate were evaluated for their ability to retain P, a typical water pollutant. Although plant growth across species was sometimes lower when exposed to repeated flooding, plant visual quality was generally not compromised. Although plant selection was limited to species native to the southeastern U.S., some findings may be translated regardless of region. Plant tissue P was higher than either leachate or substrate, indicating the critical role plants play in P accumulation and removal. Additionally, polyculture plantings had the lowest leachate P, suggesting a polyculture planting may be more effective in preventing excess P from entering waterways from bioretention gardens. The findings included that, although monoculture plantings are common in bioretention gardens, polyculture plantings can improve biodiversity, ecosystem resilience, and rain garden functionality.

Academic‐conservation partnership reveals trade‐offs in treatment method and frequency needed to restore invaded floodplain

“…River oats also produce high seed abundance per plant (Neill 2020). Practitioners chose river oats for restoration plantings due to their shade and flooding tolerance, perennial reproductive strategy, and nursery propagation potential (Morash et al 2019; Neill 2020).…”

Benefits, Inconveniences, and Facilities of the Application of Rain Gardens in Urban Spaces from the Perspective of Climate Change—A Review

“…Rain gardens are included in localized stormwater control measures (SCMs) [8]. One of the simpler definitions of a rain garden specifies it as a depressed area in a landscape with planted grass and flowering perennials that collect rainwater from roofs, driveways, or streets, allowing it to soak into the ground [9].…”

“…There are also definitions that primarily consider the purposes and benefits of using rain gardens, rather than their construction. Rain gardens are effective low impact development (LID) practices that are used in residential areas to capture stormwater runoff, to recharge groundwater by infiltration, and to remove pollutants from the water before it enters local streams [8]. Phosphorus is an example of a pollutant that is removed [8].…”

“…On the other hand, the authors of [20] count rain gardens as bioretention areas. They are also classified as localized SCMs [8]. Rain gardens are also referred to as LID facilities [16] or LID practices [8,16], as well as rainwater management practices [16].…”

Green Infrastructures and the Consideration of Their Soil-Related Ecosystem Services in Urban Areas—A Systematic Literature Review

“…Frosi et al [15] and Morash et al [65] found evidence for large volumes of runoff along streets in urban areas to have higher concentrations of contaminants, which affects the soil and the biogeochemical processes within the soil body. This can negatively affect tree growth due to the accumulation of contaminants, such as de-icing salt, in the soil layer [66].…”