What is a Green Street?
A green street is a stormwater management approach that incorporates vegetation (perennials, shrubs, trees), soil, and engineered systems (e.g., permeable pavements) to slow, filter, and cleanse stormwater runoff from impervious surfaces (e.g., streets, sidewalks). Green streets are designed to capture rainwater at its source, where rain falls. Whereas, a traditional street is designed to direct stormwater runoff from impervious surfaces into storm sewer systems (gutters, drains, pipes) that discharge directly into surface waters, rivers, and streams.
The EPA's Green Streets: The Road to Clean Water video highlights green streets as a technique for managing stormwater and providing other economic and community benefits. Shown are examples of green streets in localities that have worked with EPA and other partners to incorporate green streets as part of their stormwater management plans. Green features shown include permeable pavement, rain gardens, vegetative curb areas, and sidewalk trees.
Anatomy of a Green Street
Green streets incorporate a wide variety of design elements including street trees, permeable pavements, bioretention, and swales. Successful application of green techniques will encourage soil and vegetation contact and infiltration and retention of stormwater. Although the design and appearance of green streets will vary, the functional goals are the same:
- provide source control of stormwater to limit the transport of pollutants to stormwater conveyance and collection systems,
- restore predevelopment hydrology to the extent possible, and
- create roadways that help protect the environment and local water quality.
Why a Green Street?
Green streets protect water quality in waterways by removing up to 90% of pollutants. They replenish groundwater supplies, absorb carbon, improve air quality and neighborhood aesthetics, and provide green connections between parks and open space. Vegetated curb extensions improve pedestrian and bicycle safety, and calm traffic.
Green streets can be used to:
- Minimize stormwater impacts on the surrounding area through a natural system approach that incorporates a variety of water quality, energy-efficiency, and other environmental best practices;
- Integrate green stormwater management features to increase infiltration and/or filtration of runoff, reduce flows, and enhance watershed health;
- Reduce the amount of water that is piped and discharged directly to streams and rivers;
- Make the best use of the street tree canopy for stormwater interception, as well as temperature mitigation and air quality improvement;
- Mitigate or prevent localized flooding;
- Encourage pedestrian and/or bicycle access;
- Improve the aesthetics of a community; and,
- Increases a community’s livability.
Green Street Resources