1/8/09 Creating Green Roofs

Creating Green Roofs. I'm Greg Martin with today's Line On Agriculture. When I saw my first "green roof," I was taken aback by the strangeness of it. Then I realized that our ancestors had already been there, done that to use a colloquialism. The "green roof" we are talking about is not the color but the style of using the roof of a building as a place to grow grasses and plants. It is becoming very popular here in the Northwest and is a great way to conserve energy and water. Recently, Secretary of the Interior Dirk Kempthorne unveiled a "green roof" on the 3rd wing of the Main Interior Building in Washington, D.C. KEMPTHORNE: For years the greening of this department has been underway so today is a very special day for those of you that have been so involved with this. I congratulate you on showing great insight on the need for a "green roof" here because with more than half of Washington DC covered with paved or constructed surfaces that do not allow water to infiltrate the ground, 75% of rainfall becomes runoff. That is one of the huge benefits. Instead of just running off the roof onto the ground, the water is captured and used by the plants. What runoff there is can then easily be collected. Runoff can create flooding problems and cause sewage to be discharged into frail ecosystems. KEMPTHORNE: To help solve this problem more than 7 years ago the National Business Center began investigating a "green roof" for the Interior Building intrigued by the "green roof" movement in Europe. Although sod roofs have been around for centuries, the modern "green roof" is a manufactured extension of the existing roof. Vegetation and soil are planted over some kind of a waterproofing drainage system. Kempthorne says we should start seeing a lot more "green roof's." KEMPTHORNE: "Green roofs" are being planned or built in several national parks and other areas under jurisdiction of the Interior Department as well as in city parks. The new visitor center in Denali National Park and the California Academy of Sciences in Golden Gate Park for example, both include "green roofs." He also says that these roofs become habitats for wild animal species. He applauded the work and encouraged more projects. KEMPTHORNE: We need to set an example for other buildings in Washington and other departmental facilities around the nation. Our "green roof" when fully planted will cover almost 6500 sq. ft. In addition to its ecological benefit, it is expected to last 50 years or longer. It will reduce our heating and cooling costs by increasing insulation, reducing wind losses and providing shade. That's today's Line On Agriculture. I'm Greg Martin on the Northwest Ag Information Network.