Enjoying the view up here

It´s an idea that´s just crazy enough to work.

Green roofs. We´re not talking about decorations for St. Patrick´s Day. It´s even more than a label for environmentally friendly construction. We´re talking about the green that you water and fertilize, and where you take the mower for a spin.

The concept of grass and plants and soil on the tops of buildings is gaining favor as a means to control stormwater. Proponents claim it could free up substantial municipal stormwater capacity, store lots of rainwater, reduce runoff, cut sewer overflows and improve air quality. The cost of green roofs initially is twice as high, but proponents claim they last more than twice as long. It´s finding use in cites such as Washington, Chicago and Portland, Ore. There was 81 percent more green roofing in 2005 than in 2004.

It´s an intriguing answer to a problem that goes largely unrecognized but is critical. The sewer infrastructure in the United States is badly in disrepair. Increased green roof applications would ameliorate the problem, lightening the burden on aging pipes.

More broadly, it´s a great example of environmental ingenuity. Rooftops are estimated to make up one quarter of the urban landscape in some settings. It could amount to a significant environmentally beneficial use of a previously unused area. I don´t know how someone comes up with an idea like that. But that kind of imaginative, out-of-the-box thinking is key to solving problems where the options and financial resources are limited. One proponent even jokes about the roofs generating additional revenue through tea plants and honey generated from bees pollinating the rooftop garden. But that, too, isn´t totally nuts.

Expecting billions of dollars to neatly fall from government coffers to repair the country´s sewer system -- now that´s nuts. Coming up with solutions like green roofs that address at least part of the problem actually is a much less crazy idea.

Allan Gerlat is editor of Waste News. Past installments of this column are collected in the Inbox archive.

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