Yesterday’s New York Times article on the Green Alley project in Chicago is fascinating. With nearly 2,000 miles of alleys in the city, Chicago is moving to porous concrete and asphalt for repaving. From the article:
In a green alley, water is allowed to penetrate the soil through the pavement itself, which consists of the relatively new but little-used technology of permeable concrete or porous asphalt. Then the water, filtered through stone beds under the permeable surface layer, recharges the underground water table instead of ending up as polluted runoff in rivers and streams.
Some of that water may even end up back in Lake Michigan, from which Chicago takes a billion gallons a year.
The Times article also discusses the other sides of the story, however, and gives evenhanded criticism of the project as well. The Dirt would like to see the city move beyond porous concrete and think about bioswales, green walls, and more. But every little step helps!