Bioswales in Portland

If you’re like me, you don’t know what the heck a bioswale is. I couldn’t even spell it 90 seconds ago. My friend Jordan, who is going into the 8th grade at the Metropolitan Learning Center, has been working on a project to build a bioswale at his school. He told me all about the project and his efforts, which were pretty impressive, which will continue when he starts up school again next Wednesday.

According to Wikipedia, “Bioswales are landscape elements designed to remove silt and pollution from surface runoff water. They consist of a swaled drainage course with gently sloped sides (less than six percent) and filled with vegetation, compost and/or riprap. The water’s flow path, along with the wide and shallow ditch, are designed to maximize the time water spends in the swale, which aids the trapping of pollutants and silt. Depending upon the geometry of land available, a bioswale may have a meandering or almost straight channel alignment. Biological factors also contribute to the breakdown of certain pollutants.” Now do you know what a bioswale is? I’ve seen a few but didn’t really know what they were about.

In Portland they’re important because essentially bioswales capture rainwater runoff rather than fill sewers, which pour out into the Willamette River allong with all the pollution it picks up along the way. There’s one downtown near PSU on 12th Avenue, which won a prestigious national award last year.

The bioswale project at Metropolitan Learning Center is expensive to implement, and Jordan has had a hand in developing the budget and getting donations. He’s even written grants for the project. I’ll be sure to follow up on his project through the fall as it keeps moving.