Pervious concrete is a cheap and effective way to curb the harmful effects of stormwater runoff.
City leaders say spongier surfaces could be the solution to polluted stormwater runoff.
Whenever it rains hard, "It would flow right off the sewers, carrying nitrogren and phosphorous and heavy metals and pet waste and all the stuff you don’t want to get into your water," says Meredith Upchurch, a landscape architect with the D.C. Department of Transportation.
But she says there’s a solution -- right in your backyard, or really your back alley.
"We've got our first permeable alley here and when the water goes in, it soaks right through. It’s going into this eight-inch slab of pervious layer of concrete and going into a gravel layer below and infiltrating into the ground," she says.
The city is using stimulus money to construct the new alley in Northeast, D.C. and eight more are planned throughout the District.