Opinion: How Daylighting Can Allow NYC’s Streets to Fight Flooding

“In most U.S. states, parking within 20 feet of crosswalks is prohibited. Known as ‘universal daylighting,’ this is primarily a safety measure that increases visibility at intersections. It also creates hundreds of feet of empty, usable curb space at every intersection.”

In mid-July, New York City experienced the second-wettest hour ever recorded in the city when more than two inches of rain fell on Central Park in the span of one hour. In the days following, experts predicted that New York City will face increasingly severe rain storms as the effects of climate change worsen. Last week, torrential downpours and flooding again deluged the city.

This problem has a solution hiding in plain sight: New York must embrace universal daylighting to create a direct pathway to repurpose curb space as rain gardens at scale.

More than 70 percent of New York City is impermeable surfaces, preventing rainfall from being absorbed into the ground. City streets make up an astounding 32,000 acres of this, totaling almost 40 Central Parks worth of space. 

In a city well-known for its walkability and good transit options, dedicating such a large amount of space to roadways doesn’t provide New Yorkers with the benefits they need. More than half of households in New York City do not own personal vehicles, and a far higher percentage of individuals—nearly two thirds of New Yorkers—don’t rely on driving for daily commuting.

Repurposing just a small portion of these 32,000 acres holds enormous potential for flood mitigation. In 2016, Philadelphia “greened” a mere 837 acres of city land over five years, reducing stormwater and combined sewer overflow by more than 1.5 billion gallons of water annually. Hoboken achieved comparable outcomes with its initiative to build and expand rain garden usage across the city.

New York can replicate this success. In New York City, sidewalk rain gardens hold up to 2,500 gallons of water each, and there is ample space in the 32,000 acres of roadbed to build rain gardens at scale. The challenge lies in securing the space for this purpose. 

The answer is right in front of us. In most U.S. states, parking within 20 feet of crosswalks is prohibited. Known as “universal daylighting,” this is primarily a safety measure that increases visibility at intersections. It also creates hundreds of feet of empty, usable curb space at every intersection. 

However, New York City does not enjoy this benefit. While New York State is among those where universal daylighting is the law, a decades-old loophole allows New York City to exempt itself from this standard, preventing curb space from being repurposed for rain gardens and other uses.

This creates challenges for reforming how New Yorkers think about and use curb space. New York City has nearly 3 million on-street parking spaces, which is far more than any other U.S. city or comparable global cities. Despite being heavily populated with transit-riders and walkers, space in the street is cemented in the minds of New Yorkers, and in our infrastructure, as reserved for parking. To fix this, city laws governing curb space must change.

Intro. 1138, a City Council bill that removes New York City’s exemption from state daylighting laws, is the common-sense solution. A simple change closing the daylighting loophole unlocks curb space for rain gardens at every intersection.

Intro. 1138 is broadly popular, enjoying bipartisan support from a majority of Council members. With no end to extreme weather events in sight, Speaker Adrienne Adams must move to pass the bill and clear the way for New York City to build much-needed green infrastructure.

New York City cannot create new land for this infrastructure; it has to work with the space it already has. That means rethinking how streets are used and converting existing impermeable surfaces into green, permeable surfaces that make the city more resilient to climate-change-driven storms.

Without universal daylighting, New York City has no realistic way to build green infrastructure at scale, manage worsening rainstorms and protect New Yorkers from the flooding that is sure to come.

Sara Lind is the co-executive director of Open Plans; Alex Morano is a communications professional and street safety advocate.