Permeable Pavement Holds Promise, And Some Doubts

"Used in Europe for decades, so-called permeable pavement allows rainwater to pass through instead of running off into rivers or lakes. Made of either porous asphalt and concrete or paving stones shaped to leave gaps at the corners, the surfaces are just starting to catch on in the area as part of the movement toward "green building," which seeks to lessen the environmental impact of development."

"Some questions remain about whether the pavement will become clogged over time and how well it will stand up to northern freezes, but environmentalists are generally enthusiastic."

"Chicago has used permeable pavement as part of a 'green alleys' program and plans to use it in streets in the next year or two, said Department of Transportation spokesman Brian Steele."