An excerpt from the book "Wild in the City - Exploring The Intertwine."
The Pacific Northwest is considered a hot spot in the nation for green infrastructure implementation. Where we used to pave, pipe, and channel, we are now reclaiming permeability, planting trees, and restoring natural functions lost long ago to our urbanizing environments. We are creating spaces and places that are healthier, safer, and more livable for people. What's more, in the process we are providing habitat for wildlife, birds, pollinators, and amphibians.
This walking tour will give you a variety of examples of these green treasures in a place you might least expect to find them: the heart of Portland's downtown. Off we go....
Start at the south end of downtown at the western edge of Portland State University's campus at SW 12th Avenue and SW Montgomery Street.
Green Street Planters — SW 12th Avenue between Montgomery and Mill Streets: When it rains, street runoff that isn't properly managed carries dirt, oil, chemicals, and other pollutants into rivers and streams. Four infiltration planters on SW 12th show a more natural stormwater management approach. Stormwater flows along the curbs into the planters where vegetation and soil slow down and filter pollutants before the water soaks into the ground. Look for the interpretive sign that provides a diagram of how it functions. Next walk south along 12th Avenue, take a left at Montgomery, and go to the courtyard on the east side of PSU's Epler Hall.
Creative Downspout Disconnect, Stormwater Planter, and Reuse — Epler Hall, SW 12th Avenue and Montgomery Street: The plaza outside Stephen Epler Hall demonstrates an artful and interesting stormwater treatment. Roof runoff from the building flows to river-rock splash boxes, then into granite-block lined channels, conveying stormwater to a system of vegetated stormwater planters. Instead of being piped underground and out of sight, the water is visible and celebrated. These "runnels" also collect runoff from surrounding downspouts and pavement. The soil and plants in the planters filter water before it collects in a storage vault for additional filtering before the water is pumped into the building to flush toilets — saving some one hundred thousand gallons of potable water each year. See the interpretive sign for more detail, then simply turn around to see the ecoroof on PSU's bike garage.
Ecoroof Bike Garage — West of SW 12th Avenue on Montgomery Street: This ecoroof keeps stormwater from a 1,120-square-foot surface from ending up in the sewer. Overflow trickles into the planter before going to the drain. Now walk east for half a block and take a right (south) at SW 11th Avenue, a pedestrian-only street. Go half a block and take a left through the Walk of the Heroines, one block south of Montgomery Street. Continue one more block to the South Park Blocks.
Mature Canopy Trees — PSU Park Blocks: These are the oldest park blocks in Portland, with over three hundred trees including poplars and elms which contribute an estimated $3.4 million in aesthetic and environmental value to the city. Research has shown that a mature tree, such as one of the elms found here, can absorb up to 550 gallons of stormwater a year. Next walk left, diagonally back to SW Montgomery Street.
Montgomery Green Street — PSU North Plaza between SW Park Avenue and Broadway Street: The Montgomery Green Street project is an example of one of Portland's first Green Street connectors. Green streets provide facilities for stormwater management as well as safe and pleasant routes to encourage people to walk and bike whenever possible. The site is graded so that water flows into the landscaped planters to be filtered and managed. The vegetation and trees provide a respite from the hard surrounding pavement. Now cross SW Broadway, continue walking east on SW Montgomery under the sky bridge, and cross SW 6th Avenue to Montgomery Plaza.
Stormwater Fountain Planters — Urban Center Plaza between SW 6th and 5th Avenues: The Urban Plaza block was a retrofit of an existing plaza. The fountains were in need of repair, and so the opportunity was seized to cut away some of the existing impervious bricked area, inserting the green infiltrating facilities that now manage runoff from portions of the plaza. This is an excellent example of being able to capitalize on redevelopment opportunities to integrate a green element. It is said that a city redevelops every forty years. Bit by bit, we can reclaim our urban spaces to realize greater benefits for people and the environment. Continue east on SW Montgomery, then cross 4th Avenue and turn left (south). Walk three blocks to SW College Street.
Green Street Curb Extension — SW 4th Avenue and College Street: Operating much like the 12th Street planters, this facility is different in that it extends into the street, replacing pavement. Considered the workhorse of green street designs, vegetated curb extensions are often coupled with efforts by the city's bureau of transportation to slow traffic and create safer pedestrian and bicycle experiences. Search for where the water enters and exits the curb extension. Remember that water flows downhill.