Impervious surfaces (such as driveways) limit the amount of stormwater capture and retention. During rain storms these surfaces (built from materials such as asphalt, cement and concrete) along with rooftops, carry polluted stormwater to storm drains, instead of allowing the water to percolate through the soil. This causes flooding as there is no absorption into the ground. Most municipal storm sewer systems discharge stormwater, untreated to streams, rivers, bays. In New York City, my understanding is that the overtaxed sewage system overflows into the East River.
So,…controlling the amount of stormwater runoff from urban homes is paramount in creating green infrastructure. The challenge is to allow the stormwater to percolate into the soil or ground, thereby reducing levels of urban runoff.
Thanks to a wonderful client of ours in Brooklyn, my partner Dinorah and I designed a sustainable solution to their problematic residential driveway in the midst of redesigning the entire property. The existing asphalt was cracking, pot-holed, consistently failing and flooding during rainstorms. As per local ordinances we could not repave + re-pitch the driveway to direct stormwater into the street. As we were demolishing the pressure treated wood deck in the rear, we chose to create a pea gravel driveway with secured wood boards from the demolished deck (which would then allow the stormwater to percolate down). The broken up asphalt driveway was then used to provide fill for the newly designed above grade stone deck. Only the pea gravel was trucked in, since we used material on-site to produce this. Best of all, the client reaped a tremendous cost savings through this solution!