One sunny Wednesday recently, several dozen people gathered at a house in Northeast Portland to watch workers pour concrete.
Slow news day? Not quite. The wet stuff being poured was pervious concrete, a nature-friendly paving material that helps protect water quality and fish and wildlife habitat. The observers at the Oct 20 pour, who included design professionals, school district staff, a contractor and staff from nine cities and counties, were there to better understand the installation process and talk with experts.
Pervious concrete is rapidly increasing in popularity as a nature-friendly building practice. Porous surfaces, such as pervious pavement or pavers, allow rainwater to pass through them and soak into the ground instead of flowing into storm drains. Pervious pavement allows water to be filtered through natural microbes in the pavement and soil, allowing the microbes to "eat" hydrocarbons and clean the water. As water soaks through the soil it is also cooled, so when it reaches a stream it will not shock fish who are very sensitive to even small increase in temperature. The result: healthier urban waterways.
Metro partnered with Home Builders Association, Earth Advantage, City of Portland and Evolution Paving Resources to provide this behind-the-scenes workshop at the Water House, a demonstration project showcasing nature-friendly landscaping and residential green building practices. The Water House is currently under construction and will open in early 2011 to demonstrate what people can do to protect water quality and reduce water use at home.
The pervious concrete workshop was supported by Metro’s Nature in Neighborhoods initiative, which encourages habitat-friendly development practices without regulation. Such demonstrations help demystify nature-friendly building practices, providing experience and training to those involved in development and construction projects. With such high demand for demonstration opportunities, Metro and its partners have committed to providing more in the coming year.