Have you ever walked down the street and noticed a blossoming garden between the curb and sidewalk? You may have thought this bioswale brightened up the block, but beneath its flourishing exterior it also works to absorb, slow, and filter stormwater flows. In other words, it is a form of green infrastructure.
What is green infrastructure? Think of it like a toolbox of approaches to manage stormwater, reduce heat island effects, and increase ecology and biodiversity. Using natural systems, green infrastructure can help mitigate climate change effects such as increased frequency and intensity in rainfall, flooding, and storms as well as rising temperatures and sea levels.
The WEDG® (Waterfront Edge Design Guidelines) program recognizes that green infrastructure can have multi-faceted purposes that improve the resilience and ecology of a waterfront project. The use of green infrastructure practices can be found throughout Category 4, Natural Resources of the WEDG Manual:
- Under Credit 4.9, Reduce and Manage Stormwater Quantity, green infrastructure can be used to clean freshwater discharge when excess stormwater primarily drains off the land. Green infrastructure can also improve stormwater discharge quality under Credit 4.10 by reducing the Total Suspended Solids (TSS) and other particles from the existing conditions.
- Projects can earn a point for using green infrastructure to treat at least 20 percent of wastewater under Credit 4.11, Reduce Water Use. Example design solutions include advanced hydroponic reactors, constructed filtration wetlands, algal turf scrubbers, and the use of living machines.
- Under Credit 4.12, green infrastructure can be used to reduce contribution to urban heat. Example design strategies include green roofs, pervious pavement, maximizing planting and canopy cover, using green walls and structures and reducing heat loading on vertical walls.
- Multiple credits reward projects that include nature-based design features such as wetlands, mangroves, berms, and reefs, which protect against flooding, wave damage, and shoreline erosion. In addition, points are available for nature-based design features that promote aquatic habitats and ecology of the site.
It is also important to note that in order for green infrastructure to be most effective, it must be maintained over the long term. WEDG also asks that projects include maintenance and adaptive management plans throughout these credits to ensure ongoing performance and longevity of these features.
Green infrastructure has been used in a wide range of ways on WEDG Verified projects, yielding flood protection, stormwater management, and urban heat mitigation.
A Natural Drainage System
In Brooklyn Bridge Park, green infrastructure is built into the park’s sustainable stormwater management. Passing through the park, users may notice an abundance of greenery, including rain gardens, water-absorbing lawns, and planted areas which are used to absorb rainwater into the ground. In specific areas, excess stormwater is treated by above-ground landscape elements and captured into underground storage tanks. The stormwater is then recycled through naturalized water features and used to supply the park’s irrigation needs. Simultaneously, the native plants also create multiple habitats which support the ecology of the park. The result is a natural drainage system, using vegetated swales, filter strips, constructed wetlands, and other strategies.
Restored Wetlands
Located in the South Bronx, Oak Point / McInnis Cement was once home to New York City’s largest illegal landfill but is now host to both maritime industry and three acres of restored wetlands. Through an innovative pathway, the site sends cement through pipes under wetlands to the waterside terminal. The wetlands provide significant flood protection and act as natural sponges that can absorb and slow the release of rainfall and other collected water. Besides providing water storage, wetlands are also ecologically rich, natural water filters, reduce shoreline erosion, and can even store carbon within their plants and soil rather than releasing carbon dioxide into the atmosphere. Oak Point went a step further and demolished deteriorating wooden piers to build a stone wave attenuator, which now helps to reduce the impact of storm surge on the wetland area.
A Natural Barrier
The anchor to New York City’s curbside recycling program, Sunset Park Materials Recovery Facility in Brooklyn utilizes natural barriers to protect its shoreline. Using material dredged from the Kill van Kull, three breakwater reefs were built near the shore of this industrial site. These reefs help reduce wave energy toward the shoreline, providing stabilization and protection from erosion. Simultaneously, these natural breakwaters also support in fostering marine habitat.
Permeable Pavement
To be completed in 2026, Jose Marti Park in Miami, Florida will be mostly pervious – comprising about 87 percent of the total site area. The site’s permeable pavement will reduce and treat stormwater runoff. Underground stormwater retention areas including a stone filter bed and biosorption activated media (BAM) layer will filter and remove TSS, improving stormwater discharge. In addition to providing stormwater management, the site’s permeable pavers will reduce the absorbed temperature of the ground and because of their density and color, less heat will be released from the ground throughout the night. The project will also increase tree canopy coverage across the park, which will help to cool the area rather than contribute to urban heat island effect.
As climate change impacts continue to intensify and become more unpredictable, green infrastructure can provide adaptable and resilient solutions for waterfront sites as well as complement existing grey infrastructure. Under Credit 2.1, Provide Quality Public Access Areas on the Waterfront, the WEDG Manual outlines how green infrastructure can help raise awareness among public users of the design connections to natural systems. That is, incorporating a rain garden or bioswale on a project site not only helps to create an enjoyable and functional green space but also acts as a reminder to the public that when it comes to resilience, nature and design are interconnected.
The Functionality of Green Infrastructure
August 10th, 2023
August 10th, 2023
Via The Waterfront Alliance, a report on green infrastructure:
This entry was posted on Thursday, August 10th, 2023 at 5:52 am and is filed under Green Design, Resilient Infrastructure. You can follow any responses to this entry through the RSS 2.0 feed.
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'Black Swans' are highly improbable events that come as a surprise, have major disruptive effects, and that are often rationalized after the fact as if they had been predictable to begin with. In our rapidly warming world, such events are occurring ever more frequently and include wildfires, floods, extreme heat, and drought.
'Green Shoots' is a term used to describe signs of economic recovery or positive data during a downturn. It references a period of growth and recovery, when plants start to show signs of health and life, and, therefore, has been employed as a metaphor for a recovering economy.
It is my hope that Black Swans / Green Shoots will help readers understand both climate-activated risk and opportunity so that you may invest in, advise, or lead organizations in the context of increasing pressures of global urbanization, resource scarcity, and perils relating to climate change. I believe that the tools of business and finance can help individuals, businesses, and global society make informed choices about who and what to protect, and I hope that this blog provides some insight into the policy and private sector tools used to assess investments in resilient reinforcement, response, or recovery.