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Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Avenue, Room 1000, Portland, OR 97204

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Portland's First Stormwater Green Wall


Flipping a green roof on end is a new way to catch stormwater runoff.

This week, Metro dedicated a stormwater green wall at the Portland Expo Center.  Environmental Services, Metro, and Greenworks worked together to design and construct the green wall.rain drips through planters on green wall

Many green walls are for aesthetics or to help cool the air.  The Expo Center green wall is different because it manages rainwater that runs off the roof.  Runoff flows by gravity through the green wall system, where native plants help filter and soak up the water.

dedication of green wallDevelopers have asked us if green walls can help meet Portland’s stormwater management requirements.  We will monitor the performance of the new Expo Center green wall to help answer that question.  The bureau will also use monitoring information to design future projects.

The 60-foot by 30-foot green wall took two years to design and construct. A $100,000 U.S. Environmental Protection Agency grant and contributions from Metro and Environmental Services funded the project.

Check out the wall if you're at the Fall Home and Garden Show this weekend!

Read more about the new green wall in this article from the Daily Journal of Commerce and on Metro's website


Alien Plant Invader: Tree-of-heaven


Don't let the name fool you...

It's been a while since we posted an invasive plant profile.  This one is about an invasive tree with some interesting characteristics.  We hope you'll help get it under control in Portland.

tree of heaven growing along curb

Sometimes referred to as ‘The Widowmaker’ and other more colorful language, tree-of-heaven (Ailanthus altissima) has made a good living filling in bad habitat like sidewalks and freeway sound walls, as well as yards, parks and other spots around the city. It’s well-known for using invasive roots and huge amounts of winged seed to clear a space for itself. 

In addition to these physical strategies, tree-of-heaven uses chemicals in its roots to kill off or limit the growth of neighboring plants. For all of these reasons, tree-of-heaven threatens a wide range of native plants and trees and reduces diversity in our urban forest. This rolls back the investment Portlanders have made in the healthy parks and natural areas that keep our water and air clean.

On top of its environmental impact, tree-of-heaven is hard on our homes and neighborhoods. The leaves of male trees smell terrible, like rancid peanuts or well-used gym socks. Because tree-of-heaven grows so fast, its wood is very brittle, leading to substantial branch drop. It doesn’t even take high winds for large limbs to fall on your car or roof (or head). Fast-growing trees can also become expensive to remove, so acting sooner, rather than later, is often the better choice. 

tree of heaven with fall colorsTree-of-heaven is a Class B invasive species in Portland (see the Portland Plant List). Fully-grown tree-of-heaven can be up to 60-70 feet tall. Trees flower in June or July, and form dense clusters of winged seeds by July or August. Leaves have 11 or more pointed leaflets, which are easily confused with those of black walnut leaves. Other tree-of-heaven look-alikes, such as ash and black locust, have rounded leaflets.

What can you do? Remove tree-of-heaven sprouts as soon as they emerge during the summer, though you may find that the “seedlings” are actually growing from the ends of the tree’s roots! This ability to sprout from roots makes tree-of-heaven hard to manage and difficult to remove, typically requiring an herbicide. But, if you keep at it, frequent repeated cuttings of sprouts and seedlings may exhaust the plant’s reserves and limit the re-growth. 

tree of heaven leavesIf the trunk is 12” or more across, or growing along the street, removal may require a permit. As a general rule, Portland Parks Urban Forestry regulates all street tree (as well as large tree) activities including permitting for planting, pruning, and removal. To obtain a permit, or for more information, please call 503-823-4489 or visit  

Property owners are welcome to contact Mitch Bixby at Environmental Services with non-permit questions.

The Plant Conservation Alliance also has an older, but helpful fact sheet at

Invasive species affect us all. They damage our forests, our streams and rivers, and our property. Nationwide, damages associated with invasive species are estimated to be $120 billion each year. In Oregon, the control of invasive weeds and the cost of the damages they create amounts to about $125 million each year. We know that it costs a lot less to control new invasive plants before they become infestations, but we need everyone’s help. Read more here about the problems caused by invasive species and why BES is particularly concerned about their impact on water quality.


Catch up on previous Alien Plant Invader posts:

Join the Weed Warriors to remove invasive plants at Mt. Tabor Park

The group will meet 9am-Noon on Saturday September 27th and Saturday October 25th

The Friends of Mt. Tabor Park (FMTP) Weed Warriors are key partners in the city's effort to remove invasive plants and restore native plants in the natural areas at Mt. Tabor Park (find out more at This reduces stormwater runoff to improve watershed health, enhances habitat for wildlife, and protects Mt. Tabor's forests. Photos and more information about Weed Warrior events are at

The efforts of friends and neighbors make many of our city's parks and natural areas safer and more beautiful. At Mt. Tabor Park, the FMTP Foot Patrol keeps the park safe and clean, FMTP volunteers staff the Visitor Center to inform visitors from around the globe about the park, and FMTP Weed Warriors restore natural areas by removing invasive vegetation and planting native plants.

Want a fun way to be active outside, meet friendly neighbors, and help improve Mt. Tabor Park? The Weed Warriors meet at Mt. Tabor Park from 9:00 a.m. to noon on the last Saturday of every month between April and October. The final opportunities this year are on Saturday, September 27 and Saturday, October 25. Meet at the kiosk next to the amphitheater parking lot. Go to for more information.

Fanno Creek Outfall Project Update


Improving our stormwater system to protect the stream.

construction crew replacing pipeConstruction is nearly complete on a project in southwest Portland to replace a deteriorating stormwater pipe.  This project will help improve water quality in Fanno Creek.

The pipe carries stormwater runoff from streets and other hard surfaces in parts of Hillsdale, and drains into Fanno Creek.  Stormwater runoff carries dirt, oil, and other urban pollutants that can impact water quality in rivers and streams.  Portions of the old 12-inch wide, 130-foot long pipe were badly corroded and failing. 

The project began construction this summer and is expected to be complete later in September.  Crews have finished installing the new pipe across Beaverton-Hillsdale Highway and repairing the outfall in Fanno Creek. The project includes closing a section of SW 21st to reduce sediment that flows to the creek, and to increase traffic safety. A section of pavement will be removed to create a swale with native plants to help capture stormwater pollutants. 

Crews have also stabilized the slope down into the creek and will be applying grass seed soon.  Re-vegetation staff are currently working to remove invasive species, and will be planting native plants on about one acre around the work areas this winter and next winter.

For more information visit our project website

Learn more about the Fanno Creek Watershed here, and at the Southwest Watershed Resource Center.

(post edited 9/23/14) 

Portland’s new Comprehensive Plan: Proposed draft is available for public review


There are several ways you can learn more and comment on the plan.

cover graphic from Comprehensive Plan draftThe Comprehensive Plan is Portland’s 20-year plan for handling growth, guiding development and providing infrastructure, such as streets, sewers and water. The State of Oregon requires that all cities in Oregon have a comprehensive plan. Since Portland’s Comprehensive Plan was first adopted in 1980, a lot has changed in our community, so it was time for an overhaul.

The Proposed Draft of the new plan is now available for public review and comment. The Bureau of Planning and Sustainability led technical work and collected community input over the last two years to create the plan. Environmental Services and other bureaus were part of that effort. The final plan will be adopted by City Council next year.

The proposed Comprehensive Plan builds on many other plans, including visionPDX, the Portland Plan, Climate Action Plan, and Portland Watershed Management Plan. It sets the stage for a healthy, prosperous, resilient city. There are four main parts:

  • Goals and Policies
  • The Comprehensive Plan Map, which serves as the basis for current and future zoning
  • A list of significant projects needed to support future growth
  • Portions of the Transportation System Plan (TSP)

There is also a supporting Citywide Systems Plan that details planned infrastructure investments, including sewer and stormwater projects.

Learn more about the Comprehensive Plan from the comfort of your couch through these helpful storyboards and videos.

green street facility Some of the new policies that reflect a shift in thinking since 1980 are about:

  • Considering the impacts of development on drainage and water quality
  • Managing stormwater based on the conditions in different parts of town
  • Restoring our rivers, streams and overall watershed health
  • Preparing for climate change
  • Using green infrastructure to keep our water and air clean
  • Cleaning up brownfields and using that land for new jobs



  • View changes and comment from your kitchen table with online Map App
  • Testify in person at one of these public hearings at the City’s Planning and Sustainability Commission:

September 23, 2014 at 5 p.m.
(Focus on Goals and Policies)
1900 SW 4th Avenue, Room 2500A

October 14, 2014 at 5 p.m.
(Focus on Maps)
Community location TBD, see

October 28, 2014 at 5 p.m.
(Focus on Maps)
Community location TBD, see

November 4, 2014 at 4 p.m.
(Focus on Citywide Systems Plan and
Transportation System Plan)
1900 SW 4th Avenue, Room 2500A