What exactly is a “green street?” According to the City of Portland, a leader in green street design and implementation, a green street is a street that uses vegetated facilities to manage storm-water runoff. Such a system is used to compliment existing sewage systems. In one case, the Glencoe Rain Garden in Portland, Oregon has been able to retain 94% of runoff!
The advantages to such a system include(s):
- The replenishing of groundwater systems through infiltration
- The creation of attractive streetscapes that enhance neighborhood livability by: (1) traffic calming (2) creating park like atmosphere (3) creating barrier between sidewalk and street
- Less storm-water runoff going to treatment facilities thereby reducing the cost to treat storm-water runoff.
According to US EPA, facilities that filter storm-water through vegetation and soil have been shown to reduce total suspended solids (TSS) by 90%, organic pollutants/oils by 90% and heavy metals by more than 90%.
Types of Green Streets
- Stormwater Curb Extension
- Stormwater Street Planter
- Rain Gardens
- Simple Green Street
Stormwater Curb Extension
- transform curb lane into a landscape area
- creates curb extensions ideal for pedestrian crossings
- can be used as a tool in traffic calming
Stormwater Street Planter
- works well in areas of limited space
- still allow for adjacent street parking or travel
- creates buffer between pedestrians on sidewalks and automobiles on streets
- Requires larger amount of space, but is considered the ideal storm-water management technique.
- most adept at turning awkward intersections into safe pedestrian and bicycle crossing facilities.
Simple Green Street
- created by excavating an existing planting area behind a reinforced curb.
- curb cuts are made for inflow and outflow
- landscaping with appropriate vegetation is added
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