EPA Promotes Green Infrastructure for Healthier Urban Environments

What is “green infrastructure”? Green infrastructure incorporates vegetation, soils, and natural processes to manage water and create healthier urban environments. When talking about an area the size of an entire city or county, green infrastructure refers to an assorted collection of natural areas that provide habitat, flood protection, cleaner air, and cleaner water. When referring to an individual neighborhood or smaller locale, green infrastructure refers to stormwater management systems that simulate nature by soaking up and storing water, which then can be redirected back into sustainable usage by those communities.

We are all becoming increasingly aware that climate change is affecting us, and it’s happening now. Different parts of the country are becoming wetter, drier, or hotter; green infrastructure can help improve community resiliency today and as we head into the future. The U.S. Environmental Protection Agency (EPA) considers green infrastructure to be the most “cost-effective and resilient approach to our water infrastructure needs.” EPA provides valuable information and useful resources to help community leaders and members become part of the “greenstream.” The following is a brief overview of some ways to support a green infrastructure system:

Manage Flooding

Heavy downpours have increased over the last 50 years, and are expected to become more frequent and intense as global temperatures continue to rise. Consequently, flood risk is likely to increase dramatically across the country. Among the types of flooding that will likely become more frequent are localized floods, when rainfall overwhelms the capacity of urban drainage systems, and riverine floods, when river flows exceed the capacity of the river channel. Rain gardens, underground infiltration trenches, underground storage and infiltration systems, and regional stormwater ponds are practices that complement other measures to lower flood risks.

Prepare for Drought

Drought is becoming a serious issue for many regions in the country; any water is precious and must be conserved. When rain falls on hard city surfaces it often runs directly into storm drains, directing water away. Locating infiltration-based green infrastructure practices in parking lots, along streets, and near buildings can provide an opportunity for rainwater to slowly soak into the ground, relieving stress on local water supplies and reducing the need to import potable water. Although some water will evaporate or be soaked up by plants, studies show that over time, green infrastructure can infiltrate enough rain to replenish groundwater reserves.

Reduce Urban Heat Islands

Urban heat islands are created by dense concentrations of pavement, buildings, and other city surfaces that absorb and retain heat. Planting trees and building green roofs help shade building surfaces, deflect radiation from the sun, and release moisture into the atmosphere to help to reduce the urban heat island effect. They also provide pockets of cool space for our more vulnerable citizens to find shelter from extreme temperatures.

Lower Building Energy Demands

Green infrastructure lessens the cooling and heating demand for buildings. Shading, windbreaks, and evapotranspiration created by trees and vegetative cover can lower ambient air temperatures in urban areas and lessen the need to turn up air conditioning in summer months. Rooftops are especially responsible for extensive heat loss in the winter and absorption of hot temperatures in the summer; green roofs can greatly reduce the amount of energy needed to keep the temperature of a building comfortable year round.

Spend Less Energy Managing Water

Treating and managing the movement of drinking water and wastewater requires a lot of energy and money. Green infrastructure can significantly lower municipal and domestic energy use by reducing the pumping and treatment demands by minimizing rainwater that flows into sewer systems, recharging aquifers, and conserving water.

Protect the Coast

Green infrastructure practices include retaining and supporting living shorelines, buffers, wetlands, and dunes, which help reduce coastal erosion and storm impacts on human health and property. Wetlands, for example, reduce wave heights and property damage. By comparison to hard structures like bulkheads and sea walls, vegetative shorelines provide multiple ecosystem benefits including improved water quality, aquatic habitat, and carbon sequestration.

Click here to access the “Green Infrastructure for Climate Resiliency” fact sheet.

To join “greenstream,” an EPA listserv featuring updates on green infrastructure publications, training, and funding opportunities, send an email to join-greenstream@lists.epa.gov.

To learn more about the relationship between green infrastructure and low impact development please click here for EPA’s Low Impact Development Page.

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