Construction map for the bioswale project. COURTESY ENVIRONMENTAL SERVICES BUREAU

Construction map for the bioswale project.

The Columbia Slough, 31 miles of waterway adjacent to the Columbia River, has long been one of Portland’s most polluted bodies of water. Since its use in the early 20th century for waste runoff, the slough has not improved its situation tremendously over the ensuing century due to pollution coming from street drains in neighborhoods like Argay Terrace. Now a joint project from Oregon’s Department of Environmental Quality (DEQ) and Portland’s Environmental Services bureau will see the installation of 53 “green street planters,” as well as 32 stormwater inlets, in the Argay Terrace neighborhood.

Set to break ground in September, construction was delayed until November due to a hold-up at purchasing, said Construction Manager Debbie Caselton, who does community outreach for the city’s Environmental Services bureau, in an email. Construction is forecasted to be complete by Oct. 31, 2018.

The green streets are small gardens, or bioswales, meant to filter water that runs off from the streets and sidewalks into the drains. A bioswale is any landscape piece that acts as a filter of silt or pollution for runoff water. Without them, Portland’s robust rainfall carries all the nasty pollutants from cars, homes and businesses from the streets and sidewalks straight to the Columbia Slough. We use wells next to the slough as a drinking water reserve, and the fish that swim in it carry that pollution, as do other area wildlife. A natural, low-maintenance way to filter all that pollution before it goes into our food and water is a highly coveted solution.

Legal settlements with 14 nearby businesses deemed responsible for much of the pollution in the slough has given DEQ and Environmental Services a war chest from which to wage their campaign.

Diagram of how green street planters work. Courtesy of Portland Bureau of Environmental Services

Diagram of how green street planters work.
Courtesy of Portland Bureau of Environmental Services

“There are a lot of green streets going in on Shaver, but also on [Northeast] 133rd, 125th, Prescott, and others between 122nd and 141st [avenues], that whole area right there,” says Caselton of the ambitious project. The green streets will consist mostly of rushes and sedges (grassy ornamental plants), highlighted by a selection of flowers (daffodils, camas and irises) chosen by the nearby residents from a list provided by Environmental Services.

Caselton continues, “There’s also going to be ADA [Americans with Disabilities Act] ramps put in, some inlet work and moving of some water lines. So there will be a lot of activity there, but the thing with green streets is that [their construction is] pretty phased.” Caselton stresses that the phasing of work should help lower the overall impact on residents.

The Memo also spoke with Diane Dulken at Environmental Services about what neighbors can expect.

“We work to minimize traffic impact,” says Dulken. “In this area, it’s enough of a grid that no streets will be closed. So really, the traffic impacts will be minimal, though there will be a lot of activity.”

“We have an agreement [with DEQ] that we will work on improving the sediment quality in the Columbia Slough,” says Caselton. “This neighborhood [Argay Terrace] has a particularly high volume of pollutants, so we identified this area to install the green streets to filter the pollutants. We’re also working on one in the Portsmouth area, and eventually all along the slough in the future there will be this kind of pollutant filter project.”

“They are rain gardens, and they are something that actually adds beauty to the neighborhood,” says Dulken, “so we’re working with nature to remove pollutants.”

“There are many types of green streets,” says Caselton. “These ones curve out into where you would normally park a car.” She goes on to note that this will also provide “traffic calming,” as it narrows the street a bit. This is also where local concerns regarding the project emerge.

Doug Cook, chair of the Argay Terrace Neighborhood Association, weighed in on the project. He noted that Environmental Services reached out to the community for input, though he wasn’t entirely sure the concerns they received got quite the airing they deserved.

“We’re also concerned about the environment, and we want to do our part to protect the Slough—it benefits everybody,” says Cook. “It did strike some that 53 (the number of bioswales being put in) might be a little high.” There were the obvious complaints about a loss of parking, especially with the new Luuwit View park set to open, which is anticipated to cause an increase in neighborhood traffic.

But the chief worry Cook heard was the fear of a lack of maintenance once the gardens are installed. “The bioswale at Northeast Fremont and 131st Place has four-foot thistle bushes throughout it that have been there for months. We would not call that the level of maintenance we would like to see.”

Environmental Services says the green streets will be maintained. According to a factsheet available on their website (, each garden will get up to 10 visits per year from the city to ensure they are alive and healthy and to remove invasive weeds for the “first couple of years.” After that window, the city will come by on only a seasonal basis, which might explain the seeming overgrowth on the Fremont Street bioswale.

The project doesn’t have an exact start date yet, and Dulken noted there was a possibility it could be pushed back to a later start. But the major thing the city wants residents to be aware of as the construction begins is safety.

The city’s fact sheet on the project says, “You can help keep the area safe by staying clear of all construction activities and keeping children, pets and vehicles out of construction areas,” and advises that a city inspector will be on hand during work hours to field concerns. The other main things to look out for are going to be vibrations, noise and dust from the construction work and the traffic delays and parking restrictions on the streets where the planters are going in, as well as equipment storage on residential streets. The city also warns that due to the phased nature of the building, there might be long periods of inactivity during the installation, as well as between completion and the first planting of actual gardens, due to the season in which work may reach completion.

“Green streets are a proven technique that Environmental Services has used for a long time, “says Dulken, noting there are over 2,000 such bioswales across the city.

“They can be an eyesore if not maintained,” says Cook, noting that that’s just with one. “They become a negative, and the more the city puts in, the harder it will be to maintain them. What happens when we have 54?”

Questions? Call Caselton at 503-823-2831 or e-mail her at

Information regarding the Argay Green Street Project can be found online at

Updates can be found at

Argay Terrace
In the late 1950s, homebuilders Art Simonson and Gerhardt (Gay) Stabney created the residential development Argay Terrace. Naming it after themselves and the land’s sloping nature, Argay Terrace is a distinct neighborhood within Parkrose. It lies between Northeast 122nd and 148th avenues and from Sandy Boulevard to the I-84 freeway. Development continued into the ’70s, which resulted in a mix of spacious, better-quality homes on larger lots. In addition, condominiums, apartments and adjacent businesses were added. With no through streets bisecting the neighborhood, its wide and curving low-traffic avenues give Argay Terrace an open feeling and provides many homes with stunning mountain and river views.

Argay Terrace is a well-maintained, family-oriented neighborhood of more than 6,000 people occupying more than 1,600 homes and condominiums and more than 500 apartments. Home prices range from about $250,000 to $500,000 or more.