PROJECT TYPE

  • Urban
  • Street
  • Parking

Environmental Benefits

  • Captures Water
  • Circulates Water
  • Cleans Water
  • Conserves Water
  • Ecologically Manages Stormwater
  • Reintroduces Native Plants
  • Sequesters C02

Links

NE Siskiyou Green Street

Portland, Oregon, U.S.A.
  • NE Siskiyou Green Street
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    NE Siskiyou Green Street transformed the way a 80-year-old street manages stormwater. The street retrofit project exemplifies how stormwater can be managed sustainably, instead of being allowed to overflow into already inundated local water and sewage systems.

    ASLA Honor Award Recipient, NE Siskiyou Green Street by Kevin Robert Perry, ASLA (Photo: Kevin Robert Perry)

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  • NE Siskiyou Green Street
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    The green street uses curb extensions to capture street runoff. Conventional curb extensions are often used for traffic calming and pedestrian safety. The curb extensions at NE Siskiyou Street share many of the same benefits of conventional curb extensions. However, they are different in that they are also designed to elegantly capture, slow, cleanse, and infiltrate street runoff.

    ASLA Honor Award Recipient, NE Siskiyou Green Street by Kevin Robert Perry, ASLA (Photo: Kevin Robert Perry)

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  • NE Siskiyou Green Street
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    Stormwater runoff from 10,000 square feet of NE Siskiyou Street and neighboring driveways flows downhill along the existing curb until it reaches the seven-foot wide, 50-foot long curb extensions. An 18-inch wide curb cut allows this water to enter each curb extension.

    ASLA Honor Award Recipient, NE Siskiyou Green Street by Kevin Robert Perry, ASLA (Photo: Kevin Robert Perry)

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    Once water is within the landscape area, the water is retained to a depth of seven inches by a series of checkdams. Depending on the intensity of a rain event, water will cascade from one "cell" to another until plants and soil absorb the runoff or until the curb extensions reach their storage capacity.

    ASLA Honor Award Recipient, NE Siskiyou Green Street by Kevin Robert Perry, ASLA (Photo: Kevin Robert Perry)

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  • NE Siskiyou Green Street
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    Street runoff flowing into the curb extensions is slowed, cleansed, and filtered by a variety of plant species. One plant species, Juncus Patens, has an upright growth structure that slows down water flow and captures pollutants. Juncus Paten’s deep penetrating roots are good water absorbers.

    ASLA Honor Award Recipient, NE Siskiyou Green Street by Kevin Robert Perry, ASLA (Photo: Kevin Robert Perry)

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  • NE Siskiyou Green Street
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    Nearly all of NE Siskiyou’s annual street runoff, estimated at 225,000 gallons, is now managed by its landscape system. Multiple simulated flow tests have shown that the curb extensions at NE Siskiyou Street have the ability to reduce the runoff intensity of a typical 25-year storm event by 85 percent.

    ASLA Honor Award Recipient, NE Siskiyou Green Street by Kevin Robert Perry, ASLA (Photo: Kevin Robert Perry)

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  • NE Siskiyou Green Street
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    Portland has a waiting list of residents who want similar sustainable stormwater facilities for their own streets. Using stormwater checkdams made out of packed earth covered with river rock is one example of a simple, attractive, and environmentally sustainable design element that costs very little to install. Cost-effective solutions such as these allowed the project to be built for under $20,000.

    ASLA Honor Award Recipient, NE Siskiyou Green Street by Kevin Robert Perry, ASLA (Photo: Kevin Robert Perry)

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Project Facts

  • The NE Siskiyou Green Street curb extensions include a series of mini-dams.
  • Water cascades from one “cell” to another within the dams until the curb extensions reach storage capacity.
  • The Green Street can manage 225,000 gallons of stormwater runoff per year.
  • The curb extensions converted 590 square feet of pavement into green landscape.
  • Similar green streets can be built for under $20,000.
  • Seattle Green Living Expo 2006 was hosted by High Point.