Green streets are small rain gardens that collect stormwater runoff from streets, slow its flow and allow water to soak into the ground as soil and vegetation filter pollutants. Green streets keep stormwater out of the sewer system and local streams, replenish groundwater supplies, and create urban green spaces. Green streets are a cost effective way to manage stormwater. To learn more go to www.portlandoregon.gov/bes/greenstreets.
Green street construction typically involves the following steps:
- Saw cut and remove pavement (this area is much larger than what you'll see in the end to allow for the concrete forms)
- Excavate and place concrete forms for curbs and walls
- Pour concrete and let it set
- Remove concrete forms and excavate to final depth
- Add and level soil
- Add protective matting or fabric, if needed
- Plant vegetation (typically in spring or fall)
Constructing green streets typically requires several specialized contractors to complete each step. There are often periods of inactivity between each step, most notably between completion of the physical green street and planting vegetation which occurs in fall or spring.