Generic image of New York City

Are New York's streets prepared to handle flash floods?

The city’s streets are flooding, and some zip codes are getting affected more than others

When Hurricane Ida hit the city last September, New Yorkers shared images and videos of flooded subway stations and streets on social media. Ida brought enough rain to make it the city's fifth wettest day since 1869. The flash flooding and rain killed at least 42 people — 13 in the city.

The 7.19 inches of rain that fell across the Central Park on September 1 is enough to almost completely confine the 305 foot-tall Statue of Liberty.

Queens resident Charlton D’souza recalls how the hurricane affected his neighborhood. “We were all afraid our houses were going to get damaged. Several of my neighbors lost their appliances and furniture due to flooding damage,” he said. “When buses were pulling up at the bus stops, it caused a tidal wave pushing more water into houses.”

In 2021, there were 10 flash-flood warnings issued for the city, according to data archived by Iowa State University. That’s the highest it’s been since 2006, the earliest available year in the dataset.

“We had fewer extreme weather events a decade or so ago — maybe one or two a year. Lately, it’s been five to six every year,” meteorologist John Davitt said. “Ida’s case wasn’t a failure of planning. It was a climate gone crazy situation. Ida was an eye opener … We didn’t think that type of flooding happened here,” Davitt said.”

Between January 1, 2020, and March 31, 2022, New Yorkers lodged over 67,000 street flooding-related complaints with the city government.

A recent study by researchers from The City College of New York at the NOAA Center for Earth System Sciences and Remote Sensing Technologies takes a residents’ eye approach to the problem.

The study, published in December 2021 in the Journal of Hydrology, looked at 311 complaints from 2010 to 2019 to map out, by zip code, which areas in the city get hit hardest by flooding.

Three-one-one is a residents’ hotline used to report non-urgent problems. For street flooding related issues, the complaints are routed to the Department of Environmental Protection.

For 2020, 2021 and the beginning of this year, data from the same source shows a different trend, with most complaints lodged by Queens residents, followed by Brooklynites. That said, broken down by zip codes, the highest number of complaints come from one particular zip code: Staten Island’s 10314 zipcode. Over 1700 complaints were reported from the zip code in just a year and a half.

In 2020, the city announced a $6 million infrastructure upgrade to tackle street flooding on Staten Island.

“The problem with urban flooding is that it’s hard to locate exactly where it’s happening,” Candace Agonafir, one of the study’s co-authors said.

For the study, the choice to break data down to zip code level was a strategic one, Devineni said. The inspiration behind the study was just that: a quest to find exactly where flooding occurs and potentially use the findings for future city planning.

While precipitation remained the biggest factor in predicting street flooding, the study found that for 21% of the city’s 197 zip codes manhole overflow complaints were significant to predicting street flooding.

While the findings didn’t particularly surprise Agonafir and Naresh Devineni, another co-author of the study, one conclusion did get their attention — that catch basins-related complaints are a predictor for street flooding complaints. The study found that these complaints predicted street flooding in 47 percent zip codes in the city. Catch basins are street gutters that open into sewers and are meant to prevent water clogging on streets.

The annual rainfall in New York City is about 1,270 millimeters, or 50 inches, according to the National Weather Service. The average number of days it rains in the city is 134, according to data cited in the study.

Davitt, whose meteorology career spans over two decades, gave historical context.

“Rainfall records for the city go back to the late 1800s ... This past summer, twice, we set records for the most amount of rain in a single hour,” he said.

Post Ida, in 2021, the then City Mayor Bill de Blasio announced a $2.1 billion funding plan for the city’s Department of Environmental Protection. The administration also announced the creation of a new position at the City Hall — an Extreme Weather Coordinator.

“The city is more proactive now in how they communicate,” Davitt said. “They put an emphasis on alerting the public as early as possible … The city seems to play catch up a lot.”

Manhattan

For his neighborhood, the easiest solution can really just be to pump water out regularly, D'souza said.

“Infrastructure is failing at a lower threshold now compared to a decade or so ago,” Davitt said.

D’souza agrees. While he thinks climate change is responsible for the flooding, he also places the onus on city planning, poor infrastructural upkeep and residents’ behavior for causing street flooding.

“On my block, we’ve always had flooding,” D'souza said. “I’m not even close to water.”

“We have old sewer systems … but with that in mind, we have to be careful with what we’re dumping down the drain,” he said, adding that people tend to be careless about proper waste disposal which leads to increases in drain pipes getting clogged.

City’s department of environmental protection could not be reached for comments.

“Manhattan is the new Miami,” Davitt said. “We have to future proof the city.”