Permeable Pavement Eases Flooding in New York City

Keeping Brooklyn’s streets dry after heavy rainfall just got a lot easier. That’s because this borough started installing seven  miles of porous pavement that can make a big difference in flood prevention.

Porous pavement helps to divert water from going into the already overwhelmed sewer system by allowing the water to go directly into the ground. This was necessitated by the increased rainfall the city has been experiencing, according to a news release on The NYC Environmental Protection website.

“Climate change is bringing with it rainstorms that can overwhelm our sewers and cause flooding across the five boroughs, which is why we are investing in tools that will divert rainwater away from the sewer system, such as porous pavement,” NYC Department of Environmental Protection Commissioner Rohit T. Aggarwala said in the news release.

“Brooklyn got hit particularly hard by Tropical Storm Ophelia last September and this new porous pavement will help to ease pressure on the sewer system and protect residents during future storms.”

Finding a solution
New York City’s five boroughs have 500 miles of sewers and 150,000 catch basins that are the backbone of its storm water collection. But this is no longer enough. That’s why the city is investing in new green technology to help intercept the water from storms before it goes into the sewers.

This technology includes using porous pavement that allows the water to be naturally absorbed into the ground unlike traditional asphalt roadways. Porous pavement is installed on the curbline of streets so the water doesn’t flow into catch basins located on corners.

“Roadways, as you know, are built with a crown… So we don’t need porous pavement everywhere. We need it on the sides because the water will naturally drain to the side and that’s where it’ll sink in,” Aggarwala said.

While the city has trialed the use of porous pavement, this will be the first time it is being widely implemented. But it cannot be used on every street due to sewer, water main, and private  infrastructure.

Where is the pavement being installed?
The city is installing the porous pavement in three neighborhoods in south Brooklyn, including Midwood, Sunset Park and Kensington, reported Brooklyn Paper. The city is also working to upgrade the sewer system in these flood vulnerable areas. When completed, this system is expected to keep 35 million gallons of stormwater out of the sewers.

Before installing the new pavement, the city is testing the soil to make sure it can absorb the stormwater. If confirmed, the city DEP crews will remove the existing asphalt, add additional drainage stones, and then install the new porous pavement.

But city officials stress that the permeable pavement is just one tool in the fight against flooding. New York City is working on additional green infrastructure to help mitigate flooding, including green roofs and rain gardens.

There are plans to install porous pavement in other neighborhoods in Brooklyn, Queens, and the Bronx. Keeping city streets safe from flooding will help improve the lives of city residents in a time of increased rain fall and storms due to climate change.