Next generation street trees live in swales

Street swales, like this one on Southeast Division, have been going in for several years all over Portland. (sierraclub.org)
Street swales, like this one on Southeast Division, have been going in for several years all over Portland. (sierraclub.org)

It has been a few years now and Portland continues to develop its infrastructure of street swales and curb extensions.

The Bureau of Environmental Services (BES) developed and is implementing these runoff-collecting tools along Portland’s streets in an effort to keep the Willamette River cleaner.

Runoff collects in a swale in the Hollywood District. (The Oregonian)
Runoff collects in a swale in the Hollywood District. (The Oregonian)

Street swales and curb extensions are also the next generation of street tree planters, combining both the tree-planting and storm water initiatives of the city’s Grey to Green (G2G) initiative.

On Southeast Ankeny Street—the popular east-west bike avenue—BES is about to finish the Oak B Sewer Project, which saw Queen Elizabeth Hedge Maples, American Hornbeams and Black Tupelos planted in the next generation planters.

The bureau works off of an approved tree list when planting in swales or extensions, but everything’s on a trial basis, said Jeremy Person of BES who worked on the sewer project.

“We’ve been doing sewer pipes for 100 years now,” said Person, “We’ve been doing swales—big time—for maybe two, three years now.”

What types of trees do you think would be best for Portland urban street swales or curb extensions?

–Toshio Suzuki