This is Street Wars, a weekly series on the battle for space on New York’s streets and sidewalks.

It was a sunny day in Borough Park, Brooklyn, and city officials were standing in the street, staring at the pavement.

A man in a hard hat and yellow vest turned on a hose, and water flowed out onto the street. Most streets are covered in standard asphalt, a hard surface that water pools on top of. But in this case, the water disappeared, seeping through the pavement before it reached the curb.

This was permeable pavement, and it might already be on a street near you: In the last fiscal year, New York City’s Department of Design and Construction has installed about four miles’ worth of the porous material.

You might not even recognize it if you see it, because aside from its slightly lighter color, it looks and feels like any other pavement. Your car could be parked on it right now.

Many New York City neighborhoods are prone to flooding — and climate change means the problem is only getting worse. In order to understand why, I reached out to Bernice Rosenzweig, a professor of environmental science at Sarah Lawrence College and a contributor to a new report on flooding in New York City.