Building Green Cities

      View selections from the book at the end of this post.

Moderator: 
Mike Houck  

[Discussion topic: Wild in the City: Exploring the Intertwine]


This past weekend I took a seven-mile stroll from my northwest Portland apartment to nearby Forest Park.  Half-way back I heard that shrill-high pitched call of a bald eagle.  Then, there were two, four and finally six bald eagles kettled high  above the forest canopy---the hot white light of the sun's glare making it impossible to tell young from adult.  Six bald eagles in a 5,000-acre forest, a ten minute walk from my home in the densest neighborhood in the Portland metropolitan region.  I'm tempted to use my last blog to recount similar encounters with the urban wild over the past forty-two years. 

Instead, I'm go to go all wonky on what some might consider the esoterica of green infrastructure and ecosystem services, without which I am convinced, ultimately, there would be no urban wildlife.  But to some, such as Lisa Jackson, Environmental Protection Agency administrator, green infrastructure has gone mainstream.  Just in town for a national rivers conference, Jackson spent her time visiting rain gardens, bioswales, and green roofs and proclaimed Portland a world class city when it comes to green infrastructure. 

 

If you have a copy of Wild in the City, A Guide to Portland's Natural Areas, which we published in 2000, you'll note the all new edition added a chapter devoted to exclusively to green infrastructure and stormwater management, a nod to the fact that in the intervening eleven years there have been exciting advances in integrating the built and natural environments through innovative green infrastructure programs. 

Twenty-odd years ago I took a phone call from a public policy professor at Portland State University.  Always the curmudgeon, he berated me over the phone for "wasting my time working with park and wildlife agencies."  He growled, "I've got three words for you-----Clean Water Act!"   If we were to create a truly green city and region, he insisted, we needed people and agencies with  some real "juice"----sewerage agencies!  Taking professor Churchill's advice, our 1990 Country In The City symposium was co-sponsored by the Tualatin River's Unified Sewerage Agency, Portland's Bureau of Environmental Services, and U S EPA's watershed program.  The theme for the symposium was "Restoration of Urban Stream and River Corridors and Wetlands."

Most cities have high rates of hard, 

impervious surfaces that collect 

stormwater and convey it to the 

nearest storm drain, short-

cutting natural hydrologic cycles.  

 Photo Mike Houck

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.

Patrick Condon, Univ. of British Columbia, 

urges us to  build "greener, lighter, smarter, 

cheaper" by reducing impervious 

surfaces and infiltration urban 

stormwater. Photo Mike Houck

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.        

L. Stormwater as art. This water feature collects water from a

rooftop and brings stormwater to the attention of passersby.

R. Curb extensions with attractive native plants not 

only infiltrate stormwater, but are an amenity 

to the neighborhood and calm traffic.  

Photo Mike Houck

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.

Ecoroofs attenuate stormwater by 

capturing and storing is during peak 

rain events, and can also be beautiful 

additions to the building

 

Bioswales like this one allow water 

to infiltrate into the groundwater.   

Photo Mike Houck

Green Infrastructure

Salmon Creek Greenway in Vancouver, Washington 

has been protected for multiple values, including 

flood reduction, water quality and fish and wildlife 

habitat as an element of Vancouver's green infrastructure.    

Photo Mike Houck

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.  

Ecoroofs

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. 

The next agenda for ecoroofs is 

to improve their habitat value for 

species like this male 

Anna's hummingbird.   

Photo Mike Houck

Tom Liptan, ecoroof expert, has had 

a huge impact on expansion 

of ecoroofs in Portland.   

Photo Mike Houck

Portland's ecoroof renaissance emerged in 1990 to manage rain to reduce stormwater runoff and reduce pollutant discharges. Research has demonstrated that ecoroofs  provide excellent stormwater management benefits. In fact, city zoning codes have been re-written to provide  incentives to developers to add more than six acres of ecoroof throughout the city.  Portland's Green Building Policy (‘GBP’) requires ecoroofs on all city-owned facilities.

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.

Before. 

 Half-mile Lane restoration in the 

Tualatin Basin.   

Courtesy Clean Water Services.

After

Restoration of 25 acres of wetlands and 

riparian areas along Roderick Creek and 

one-quarter mile of Gales Creek.   

Courtesy, Clean Water Services

Wapato Wetlands in the Tualatin Basin is the newest unit of the 

Tualatin River National Wildlife Refuge.  Photo Mike Houck

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. 

Portland projects a $63 million in savings over using piped solutions alone in constructing a new separated 

stormwater system in southeast Portland.  This was done by investing $11 million in green infrastructure solutions.   

The gray column represents grey infrastructure costs, green represents a mix of grey and green infrastructure.   

Courtesy, Portland Bureau of Environmental Services. 

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.

View selections from the book:

Gimme Shelter: In Praise of Portland's Urban Canopy
Who'll Catch the Rain?

Mr. Pish and the Horse Chesnut