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.
Developers 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!