Wild Read: Building Green Cities
Author: Mike Houck, Wild Read
Posted: May 8, 2012

Read the full story at Wild Read.

Today, standing on an impervious sea of concrete on Sandy Boulevard in northeast Portland it's unimaginable how the urban landscape could possibly be connected to or influence the Willamette River, flowing two miles to the west.  From where I stand the urban water cycle is out of sight, out of mind.  It's been engineered out of our daily lives. Every street's lined with a mind-numbing number of mini-dams—curbs—that channel rainwater into the nearest storm drain.  From there it's a long circuitous, piped journey to the nearest stream, river, or wetland.

In winter this tsumani of urban stormwater, which would otherwise have replenished the groundwater, is instead discharged via underground conduits to nearby streams and wetlands—wreaking havoc on native plant communities and eroding stream channels.  Conversely, during hot summer months cool groundwater that would otherwise have supported salmon and other temperature sensitive aquatic life has long since made its way to the Pacific Ocean, leaving local aquatic systems high and dry.  And, the really bad news is these winter and summer extremes are likely to increase with climate change.

Fortunately, the concepts of green infrastructure and ecosystem services have slowly begun to filter into urban planning and becoming embedded in local and regional watershed management policies.  Sewerage agencies have morphed into watershed health bureaus. The Tualatin River basin's Unified Sewerage Agency is now Clean Water Services and Portland's having changed its mission, logo (Great Blue Heron) and name, is now the Bureau of Environmental Services.

The Portland Experience—Grey to Green
Portland is using green roofs, green streets, disconnected downspouts, bioswales, rain gardens, and expanding the city's urban forest canopy to complement, and in some cases replace, highly engineered, expensive grey infrastructure (pipes, concrete, streets) with cheaper, greener, smarter methods of managing urban stormwater.  One long term goal is at least 33% city-wide canopy coverage.       

Formerly, stormwater was treated as a nuisance to be gotten rid of as quickly as possible, put a maze of underground conduits.  Now, stormwater is  recognized in Portland's Watershed Management Plan as a precious natural resource to be managed on site if possible, and reintegrated into the city's expanding green fabric.  Former city commissioner and currently Portland's Mayor Sam Adams committed $55 million in 2008 to the city's new grey to green initiative which called for planting over 80,000 trees, constructing 43 acres of ecoroofs, removing culverts to provide more salmon habitat, replacing invasive plants with native vegetation, constructing 900 green street projects, and acquiring more than 400 acres of the city's most sensitive fish and wildlife habitats.

Green Infrastructure
The Conservation Fund pioneered the concept of green infrastructure which they define both as "as a network of natural areas and open spaces—woodlands, wetlands, trails and parks—that conserves ecosystems, helps sustain clean air and water and provides many other benefits to people and wildlife."  But, they also view green infrastructure as a process, a way to identify the best lands  for development and for conservation and as a framework for local and regional planning. 

Portland's Bureau of Environmental Services' Tom Liptan, who is probably better known in London and Chicago than his hometown, has championed the use of ecoroofs to manage stormwater for a couple decades.  According to Liptan, ecoroofs started in Europe in the 1960s to mitigate economic and environmental problems caused by conventional roofing. The result was the creation of affordable, self-sustaining, living vegetative systems—extensive greenroofs (ecoroofs).  While these early roofs are still simple sedum-dominated roofs, there are efforts afoot in Switzerland and England to focus more attention of potential wildlife benefits to increase biodiversity in the city.

Ecosystem Services
The Intertwine Alliance's Regional Conservation Strategy defines Ecosystem Services as the benefits that nature provides to people. Healthy ecosystems provide provisioning” services in the form of food, timber, and water, and regulating services such as carbon sequestration and water storage in forests, wetlands, and floodplains. Open spaces provide cultural services such as places to play and relax. And complete ecosystems support pollination, biodiversity, nutrient cycling, and the other fundamental building blocks of life—generally referred to as supporting services.

Valuing Green Infrastructure—Ecosystem Services
It's possible to put a dollar value on these services to bolster support for the protection and use of nature's services in both the urban and rural landscape.

Both Clean Water Services and Portland's Bureau of Environmental Services are working with Portland State University's Institute for Sustainable Solutions (ISS) and The Intertwine Alliance, and other partners, with support from Seattle's Bullitt Foundation, to better document the economic value of protecting the region's natural landscapes and using green infrastructure—their Ecosystem Services—locally and regionally.

Riparian Restoration for Carbon Sequestration and Temperature Control
The Tualatin Basin's Clean Water Services (CWS) was faced with the possibility of spending as much as $80 million to build artificial chillers to cool effluent from their water treatment plants and as much as another $50 annually to run the chillers.  Instead, CWS persuaded regulatory agencies to allow them to plant trees and shrubs along the Tualatin River and its tributaries.

Bottom line:  the total project will cost $6 million;  involve over 36 landowners;  and eventually cover 35 stream miles.  At project's end they will have planted more than 453,000 native plants.  Relying on refrigerators to chill the effluent—as high tech a solution as one can imagine and one that yields exactly one benefit—cooler water. Clean Water Services green infrastructure approach yields multiple benefits including creating local native green industries and absorption of over 100,000 metric tons of carbon, and improved fish and wildlife habitat—and a net ecosystem services benefit of $74 million in capital costs and $50,000 in annual operational costs.

Portland's Tabor to the River
Portland's Bureau of Environmental Services has also analyzed the efficacy of blending grey and green infrastructure in their Tabor to the River program. In June, 2000 the bureau looked at constructing a new separated stormwater collection system to replace the existing undersize pipes in the southeast Portland basin. The costs estimate using traditional grey infrastructure was $144 million.  The city then re-designed the project with a combination of grey and green infrastructure (ecosystem services benefits), resulting in a saving of $63 million dollars.

The re-designed project integrates hundreds of sewer, green stormwater management, tree planting and other watershed projects to improve sewer system reliability, eliminate sewer backups in basements and street flooding, control combined sewer overflows (CSOs) to the Willamette River, and restore watershed health.

In addition to the $63 million savings in the basin, reducing the inflow of stormwater into the piped system protects the $1.44 billion investment in the city's Big Pipe project which removed CSO's from the Willamette River.

Documenting Nature's Services
In addition to these on-the-ground efforts Portland State University's Institute for Sustainable Solutions (ISS) research will provide decision makers and the general public with both scientific and anecdotal information regarding nature’s benefits to people, urban ecosystems and the economy.

One of their most ambitious programs is an Interdisciplinary Graduate Education Research Traineeship PhD program $3 million National Science Foundation grant.  This program will train 25 PhD candidates to study ecosystem services for urbanizing regions.ISS is also the home of the Bullitt Foundation funded Cascadia Ecosystem Services Partnership, which provides strategic assistance for integrating projects, facilitating communication regarding ecosystem services work in the Cascadia region (Vancouver, BC to Eugene, Oregon), especially in Oregon and Washington. For example, the Partnership is supporting a public engagement and awareness campaign to convey the value of the Portland-Vancouver region’s ecosystem services and green infrastructure, a project spearheaded by The Intertwine Alliance.

Bringing Nature into the City's Heart
Wild in the City, Exploring The Intertwine's Wild Read has described the struggle to bring nature to the fore in urban planning and M J Cody's recounting our effort to describe our region's rich diversity of parks, trails, and natural areas through Wild in the City, A Guide to Portland's Natural Areas.  Next we provided a brief history of urban greenspace planning and how we intend to co-exist with wildlife in the urban environment.  Finally, we focus on the next frontier in planning for nature in the city, an effort to bring nature into the city's heart, into the fine-grained interstices, by designing green into streets and onto rooftops, by making urban green infrastructure an integral part of the city's capital expenditures.  Documenting and valuing green infrastructure—building green cities— is the next big challenge to integrating wild in the city at every scale, from the streetscape to large regional refuges.