The Color Green: Green Streets

I wrote a paper on green streets for a course I took at UF, I recently brought it back out and reworked it a bit to use as a writing sample for an application. However, looking through some of my old papers, I realized that they are exactly what I am trying to do through this blog, which is educate and spark interest. So I have many topics to (re)explore now! Here is my writing sample on green streets...

Traditional street layouts include impervious surfaces and curb and gutter systems, which increases stormwater runoff and pollutants in the water. Green streets, which are most commonly found in the Pacific Northwest, use vegetation to enhance both public and private streets. With the help of vegetation, stormwater is redirected from waste pipes into the ground, where the water is filtered and refuels the groundwater supply.

There are different types of green streets, depending how much space there is and if the area is urban or more rural. Stormwater curb extensions extend into the street, and often become a place for safe and convenient pedestrian crossing. Stormwater Street Planters exist between sidewalks and the curb and work well where there is limited place. Rain Gardens tend to go where there is plenty of space, and they are able to create safe crossings where awkward intersections existed. Simple Green Streets dig up an existing planting behind curbs and cut the curb, replacing them with appropriate landscaping and the ability to capture runoff.

Stormwater Curb Extension

Stormwater Street Planter

Rain Garden

Simple Green Street

Cost:

In Seattle, the SEA Streets initiative found that is saved 20 percent or more of the cost of conventional street drainage by installing green streets. They spent $280,000-$325,000 per block for a green street versus $425,000-$525,000 for a traditional block.

Benefits:

Among other things, Portland has found that green streets have helped to reduce polluted stormwater in the city’s streams and rivers, reduce impervious surface, and increase urban green space. Green streetscapes do enhance the aesthetics of a community, but they also provide a natural habitat, clean and cool the air, and reduce heat island effect.

A major selling point for green streets is their ability to improve pedestrian and bicycle access and safety along roadways. With narrower streets, local car speeds tend to decrease, which also lowers the likeliness of car accidents. With the increased area of vegetation along the roads, there is a much larger buffer between vehicle and pedestrian traffic.

Without curb and gutter systems, vegetation and soil is able to filter out the pollutants in the water before returning it to the ground or surface waterways. Reducing stormwater runoff results in fewer sewer backups, less street flooding and reduced combined sewer overflows (CSOs).