Oh, the Portland rain. Though people here like to complain about it, it IS what help keeps our cityscape so lush and green. Of course, lots of places actually get much more rain than we do — Atlanta, Miami, Chicago, even New York – but what makes our climate special is not how much rain we get but how long the rainy season lasts. Yes, the gentle mist and gray starts in October and doesn’t end until late June, when we have our Rose Festival. The Rose Festival takes place Downtown, along the Willamette River waterfront to celebrate both the end of the long rain and the rose bounty it provided.
Our rain, our river, and our factory are all combined through our city’s combined storm and sanitary sewer. In other words, in many parts of Portland our storm water and our sanitary sewer share a pipe system with limited capacity. Unfortunately, when it rains sewage can be discharged into the Willamette river. Not so nice.
To solve this unpleasant problem, Portland has invested in something called the Big Pipe. This is basically a ________________________________________. Thanks to the Big Pipe initiative, Rejuvenation received an EPA Innovative Wet Weather Program grant to help manage storm water runoff from our factory.
Our main factory building is approximately 60,000 sq. feet. With our 38 inches of rain annually that makes 190,200 cubic inches of water off our building alone. That translates to 1,422,696 gallons of water that lands on our heads, or more importantly in the river. When capacity is taken up by storm water the capacity for sanitary sewage is diminished.
So, we went about trying to divert and slow down water from our roof. We came up with a plan that would divert about 12.5% of our roof run-off into movable, modular planting structures than then flow through, and into the combined sewer.
We slow down almost 178,000 gallons of water annually and the water that we release to storm has been filtered by plants and grasses living in the planters. At the time when rain is actually falling, 12.5% of the water off the building is slowing down to be filtered, then naturally metered into the system, leaving more room for sanitary sewage.
We developed the system in conjunction with Portland Bureau of Environmental Services with support of the EPA. The planters work pretty well, look pretty cool and we would love to share the info if it can help others manage storm water.