Green Streets Reduce Pollution, Enhance Pedestrian Safety

[Editor's Note: The following article was submitted to Patch by the San Mateo County Department of Environmental Health.]

Bay Area cities and towns are “greening” their transportation infrastructure—making roads and parking lots more environmentally friendly to reduce stormwater pollution.

The “Green Streets” design approach reduces stormwater pollution carried from roads and paved services while also creating a more beautiful—and often safer—environment for pedestrians and cyclists.

Paved roads and parking lots collect vehicle-related pollutants such as motor oil and brake pad dust, and other pollutants like litter, pesticides, and fertilizers that get washed into underground storm drain systems.

All of these pollutants are discharged directly into creeks, bays, and oceans, negatively impacting aquatic life and recreational activities.

Environmentally friendly green streets and parking lots, however, utilize “green infrastructure” to capture stormwater runoff before it flows into storm drains.

This filters out pollutants and reduces stormwater flows, which can help prevent flooding and erosion of creek channels.

Green streets and parking lots utilize landscaped rain gardens, swales, and infiltration planters with specially designed soil and plant mixtures that allow runoff to pond up and gradually soak into the ground, thereby removing pollutants while simultaneously creating attractive landscapes.

Strategic placement of these landscape features can also make streets and parking lots safer for pedestrians and cyclists, often providing a buffer between pedestrians and vehicles or increasing visibility at intersections.

San Mateo municipalities have been leaders in creating more sustainable transportation infrastructure.

In 2009, the San Mateo Countywide Water Pollution Prevention Program (Countywide Program) developed the award-winning San Mateo County Sustainable Green Streets and Parking Lots Design Guidebook to help municipalities, designers, and the public realize opportunities for incorporating Green Streets into transportation projects.

It has also funded multiple pilot demonstration Brisbane City Hall Rain Garden projects that provide a variety of examples of how green streets and parking lots can protect water quality and enhance communities.

These projects can be found in Burlingame on Donnely Avenue, at Brisbane’s City Hall parking lot, in Daly City at the Serramonte Library parking lot, on 3rd Avenue in San Bruno, and in San Carlos on Bransten Road.

“These projects have been a success,” said Matt Fabry, Countywide Program Coordinator. “We created the Guidebook and funded demonstration projects to help build acceptance and excitement about more sustainable ways to manage stormwater runoff, and are already seeing more projects developed throughout the County.” 

One example of this can be seen in the City of San Mateo where a new “Sustainable Street” was recently constructed on Delaware Street. Sustainable Streets combine “Complete Streets,” a program in which streets are designed to safely accommodate all modes of travel (including pedestrians, bicyclists, cars, and transit), with Green Streets.

The Delaware project reduced a four-lane roadway to two lanes in each direction with a center turn lane, allowing space for wider sidewalks, bike lanes, and stormwater treatment swales.

Integrated designs like this have proven that multiple benefits can be achieved for a community. San Mateo is demonstrating commitment to sustainable transportation infrastructure by creating a citywide Sustainable Streets Plan.

To learn more, visit Flowstobay.org/greenstreets.