By Anna Patterson, Project Director, UNC Environmental Finance Center and Amanda Peele, Project Analyst, UNC Environmental Finance Center
Climate change is increasing the severity and frequency of extreme weather events, which may cause flooding, drought, coastal damage, heat waves, and worsening water and air quality issues. These climate change impacts threaten the health and livelihoods of people in communities throughout the United States by disrupting essential social systems and damaging vital infrastructure and ecosystems. As this trend continues, communities will find it more challenging to prepare for and recover from the impacts of climate change.
Disadvantaged communities have historically been or are currently underserved and disproportionately burdened by environmental risks and hazards. These communities, especially communities of color, children, older adults, tribes, and indigenous people, are particularly vulnerable to climate change impacts, which exacerbate existing environmental injustices.
Climate resilience is the ability of a community to anticipate, plan for, and recover from climate-related hazards such as flooding, drought, coastal damage, and extreme heat, both now and in the future. By conducting a climate risk assessment, communities may understand potential climate impacts in their region and identify challenges they will likely face due to projected changes in precipitation, temperature, and sea level rise. Using this information, decision-makers may devise strategies to plan for climate-related risks that will likely affect their community. In doing so, communities can mitigate climate change impacts and bounce back better and faster from natural disasters.
The Case for Green Infrastructure
Green infrastructure (GI) installations improve climate resilience by managing stormwater, mitigating the effects of climate change, increasing biodiversity, and enhancing quality of life as public amenities. Many types of green infrastructure also cool their environment by reducing the urban heat island effect. They also reduce the impacts of flash flooding by trapping stormwater runoff during a rainstorm and releasing it slowly once the storm is over. Below are ten examples of green infrastructure:
- Bioswales are gently sloped channels that direct stormwater across vegetation, rocks, and dirt. The slowed movement of stormwater allows for filtration and reduced flooding while also providing habitat for animals.
- Rain Gardens are shallow areas, planted with native plants, that collect stormwater runoff, allowing water to filter into the ground slowly. The slow filtration of stormwater allows pollution to settle out of the water, improving water quality. Rain gardens are designed to dry within 48 hours so birds and pollinators can enjoy the garden, but mosquitos can’t breed.
- Permeable Pavement is made of permeable pavers, porous asphalt, or pervious concrete that catches, stores, and filters stormwater right where it lands.
- Rainwater Harvesting through rain barrels, cisterns, pits, aquifers, and nets allows for the capture of rain, dew, and fog for later reuse.
- Urban Forests and Urban Trees create green space in urban settings. Trees absorb rainwater, improve air quality, and reduce urban heat islands.
- Constructed Wetlands are engineered landscapes that mimic natural wetlands. They capture and store stormwater runoff and groundwater, slowing their release while trapping and storing pollutants like heavy metals, agricultural waste, and other industrial waste.
- Living Shorelines incorporate nature-based solutions to coastal erosion. Marshes, reefs, and mangroves stabilize shorelines, protect inland areas against storms, and increase biodiversity.
- Green Roofs are vegetated installations on building rooftops. They insulate buildings, which can decrease energy use, absorb rainwater, mitigate the urban heat island effect, and provide habitat for birds and insects.
- Green Streets and Alleys incorporate green infrastructure into pedestrian and vehicular infrastructure design, such as rain gardens, permeable pavement, and urban trees.
- Community Gardens are shared spaces where people cultivate fruits, vegetables, flowers, herbs, and other plants. They create a space for community building, education, increased food security, and urban green spaces.
Green Infrastructure as a Resilience Tool
People everywhere are feeling the impacts of climate change, from flooding to drought to increased temperatures, and many communities are looking to build resilience. Green infrastructure is one of the tools in the resiliency toolkit for several reasons.
GI can reduce flash flooding by capturing runoff and holding it until the storm has passed. This also allows water to infiltrate the ground slowly, filtering out pollution and recharging the water table. A recent study of city plans for green infrastructure in 20 cities showed that nearly 60% of cities defined green infrastructure by its hydrological benefits and focused on types of GI that manage stormwater as it falls.
Trees and vegetation incorporated into GI also mitigate the effects of climate change by sequestering air pollution and carbon emissions, improving air quality. Greenery also reduces urban heat island effects by providing shade and reflecting solar radiation that buildings, roads, and parking lots would otherwise absorb. This also equals financial savings since buildings need to use less energy for heating and cooling.
Green Infrastructure as a Public Amenity: Caution Against Green Displacement
Green infrastructure is often lovely, even park-like. Trees are available for lounging under, and community gardens can provide communal spaces that reduce food insecurity. Planners can use GI as a tool to build resiliency or meet municipal separate storm sewer system (MS4) permit requirements. Incorporating local voices into the planning process is key to developing GI that community members genuinely want.
Green infrastructure installations are on the rise nationwide, and with them can come a desire for housing located nearby. What might begin as stormwater management may have unintended consequences because when GI adds value to neighborhoods, property taxes, rents, and home ownership costs rise with it, and vulnerable populations may be displaced.
A recent study found that only 11% of green infrastructure plans in surveyed cities defined equity, and only 14% defined justice. Cities may find that incorporating equity and justice into GI will lead to more holistic plans and less community pushback.
Equitable Green Spaces
Green infrastructure can play an important role in climate resiliency, particularly in marginalized and disadvantaged communities. Innovative, equitable, green solutions can help these communities adapt to climate change by mitigating environmental hazards like flash flooding and excessive heat while fostering social cohesion and economic empowerment—as long as their voices are incorporated into the process. Below are some successful green infrastructure projects that have incorporated historically marginalized and disadvantaged groups into the narrative.
Proctor Creek Watershed – Atlanta, Georgia
In 2019, the Department of Watershed Management (DWM) in Atlanta announced the first publicly issued Environmental Impact Bond (EIB) would finance $14 million worth of green infrastructure in disadvantaged communities throughout the city. These neighborhoods, once the heart of the Civil Rights Movement, have become burdened with economic hardship and pervasive flooding and water quality issues in recent years. These projects, including roadside planter bump-outs, habitat restoration, bioretention features, and constructed wetlands, will manage stormwater, reduce flood risk, improve water quality, and provide public green space for the enjoyment of people living within the Proctor Creek Watershed. DWM estimates these projects will reduce 55 million gallons of stormwater runoff each year.
Lumberton Community Floodprint – Lumberton, North Carolina
Lumberton is situated along the Lumber River, which shaped the city’s economy and cultural identity. However, the river has become increasingly prone to flooding, especially in the wake of extreme weather. Torrential rains from Hurricane Matthew in 2016 and Hurricane Florence in 2018 flooded the Lumber River, causing widespread devastation to homes, businesses, and community infrastructure. As part of ongoing efforts to recover from these storms, a team of design and planning experts led by the Coastal Dynamics Design Lab at the North Carolina State University College of Design proposed land-use strategies for areas of the city that were severely damaged or vacated during the hurricanes or at significant risk of repetitive flooding. Transforming this land for public use, particularly as greenways, parks, and wetlands, may reduce flood risk by restoring the function of the natural habitat to absorb stormwater and expand opportunities for recreation and community gathering.
Walnut Creek Wetland Park & Biltmore Hills Park – Raleigh, North Carolina
Since the mid-1990s, the community-led Partners for Environmental Justice (PEJ) have advocated for investment from the city and the meaningful inclusion of disadvantaged communities in southeast Raleigh in projects to reduce flooding by restoring wetlands, address dumping to improve water quality, and provide space for environmental education and observation. In 2003, their efforts culminated in establishing the Walnut Creek Wetland Park and Nature Center. Since then, the park has expanded to incorporate more land, connect communities, and include green infrastructure. PEJ and other community groups continue to advocate for this expansion’s equitable distribution of funds and benefits. In 2023, the city began constructing green infrastructure, including bioretention areas and bioswales, in the nearby Biltmore Hills Park to reduce stormwater runoff and improve water quality in the historic Black community of Rochester Heights, which lies downstream in the flood plain of Walnut Creek near the Wetland Park.
As cities develop climate resiliency plans that include green infrastructure, they are also encouraged to involve the community in the process from start to finish. Green infrastructure has the potential to bring multifaceted benefits to the public, so let’s work towards a future where it is accessible to all.
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