It’s raining (again) in Portland today. When I’m not staffing an information desk at Central Library, I have a cubicle on Central’s fourth floor, directly under a skylight, and right now I can hear the rain pitter-pattering (actually it’s a little more than a pitter-patter at the moment) on the skylight. When I hear the rain, I think of Central’s eco-roof (also directly overhead) and the hard work that it is doing on a day like this.
Our eco-roof has a very important job: Instead of the rainwater running off the building and joining all the other runoff in a mad, gravity-inspired dash to the Willamette River – a dash that on very rainy days can overwhelm the wastewater-treatment system and cause nasty things to enter the Willamette without being treated – the Central eco-roof absorbs the rain in its planting pallets, reducing runoff by up to 70%. On top of that, it just looks nice!
Consider taking a tour of the eco-roof, viewing it from the windows of Central’s fifth floor. Just click here, or type eco-roof tour into the search box on the home page. Come more than once … it changes with the seasons.
The City of Portland’s Green Streets projects (pictured) operate in a similar way to our eco-roof. The rainwater runoff enters the plant-filled bioswales and collects there. Instead of racing into the sewer system, the water slowly filters into the soil, replenishing the groundwater. The plants themselves – like the plants on the eco-roof – filter many pollutants from the air and water. Plus – it bears repeating -- they look nice!
Read more about green streets, eco-roofs, and the way cities are altering their built environments in the books on these lists. Green cities celebrate Earth Day every day.