Portland’s Greenstreets add plants and reduce river pollution

Portland, Oregon is redesigning its streetscapes to create hundreds of new sidewalk plantings that capture stormwater runoff. As you can see in the photo from Portland’s Bureau of Environmental Strategy, these greenstreet projects not only relieve the burden on the sewer system from heavy rainfall, but also add plant life to public spaces, make streets more pedestrian and bicycle friendly, and provide habitat through native plant selection.

In addition to an excellent article on SF Streetsblog, the Portland city government does a great job of explaining the benefits of greenstreets:

When it rains, stormwater runoff that isn’t properly managed can flow over impervious surfaces picking up pollutants along the way and washing them into rivers and streams. Stormwater runoff can also cause flooding and erosion, destroy habitat and contribute to combined sewer overflows (CSOs).

Stormwater management systems that mimic nature by integrating stormwater into building and site development can reduce the damaging effects of urbanization on rivers and streams. Disconnecting the flow from storm sewers and directing runoff to natural systems like landscaped planters, swales and rain gardens or implementing an ecoroof reduces and filters stormwater runoff.