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How do you prepare a city like New York for major floods?

The flooding on September 29 was bad. The future will be, too.

Two men attempt to clear deep flood water, which has risen past their ankles, from in front of a New York City laundromat.
New Yorkers attempt to clear storm drains in Brooklyn on September 29, 2023.
Michael M. Santiago/Getty Images
Ellen Ioanes covers breaking and general assignment news as the weekend reporter at Vox. She previously worked at Business Insider covering the military and global conflicts.

Apocalyptic flooding brought New York City to a standstill Friday, with subway service suspended and murky rainwater seeping into buses attempting to navigate the city’s flooded roads.

The city’s mayor, Eric Adams, did not directly address the public till nearly noon Friday, despite the fact that his administration knew about the potential for a major downpour and possible flooding on Thursday before the storm hit. Now, floodwaters remain in parts of the city — along with questions about its ability to mitigate the effects of climate change as storms like Friday’s become more frequent.

As major climate events — like dangerous, smoky haze from Canadian wildfires earlier this summer, as well as floodwater surge from Hurricane Sandy more than a decade ago — increasingly affect the city, the urgency of climate change mitigation policies and initiatives is clear, but whether the city has the capacity, funding, and political will to undertake such a monumental task is not. Although New York has undertaken ambitious study and planning projects, the effects of Friday’s storm indicate that mitigation projects aren’t happening quickly enough, and that the city won’t be prepared for the next storm when it inevitably happens.

Of course, New York City isn’t the only place that suffered from the storms; parts of the Northeast can expect heavy rainfall over the coming week, according to CNN. In fact, unusual rainfall has had an impact throughout the US this year, and flooding has devastated areas of Libya, Pakistan, and China over the past year.

“Everywhere is susceptible to these impacts,” University of Pennsylvania climate scientist Michael Mann previously told Vox’s Li Zhou. “The western, central, and eastern US, Europe, and Asia — with one of the best examples being the Pakistan floods last year which displaced more than 30 million people.”

The city does have political infrastructure to address climate change

New York Gov. Kathy Hochul warned New Yorkers about flash floods and “havoc throughout the downstate region” on Thursday; state transit officials held a news conference about the storm Thursday, too, as the New York Times reported. Hochul tweeted about the storm and appeared on local news stations warning about the severity of the storm in the day beforehand; city officials issued a travel advisory Thursday night.

City schools remained open, though some experienced flooding and ended up evacuating, causing confusion and frustration for parents and more criticism for Adams and New York City Department of Education Chancellor David Banks. Adams defended the decision, saying, “We should be clear that we have only a certain number of school days that we can utilize, and we must make sure we meet that.”

Adams’s delayed response to the situation mirrors his reaction to dangerous air quality in the city following wildfires in Canada this summer, and it’s not the first time a New York City mayor has failed to adequately address serious environmental threats to the city and its residents, as New York magazine pointed out.

Aside from the major issue of public communication, New York City does have a political infrastructure to address climate change and disaster mitigation, Timon McPhearson, professor of urban ecology and director of the Urban Systems Lab at The New School, told Vox in an interview.

“One of the most important things that happened after Hurricane Sandy,” the 2012 storm that destroyed homes along the coast, flooded downtown Manhattan, and killed 44 people, “was the establishment of the Mayor’s Office of Resiliency, which is now part of the Mayor’s Office of Climate and Environmental Justice,” said McPhearson, who works on adaptability and mitigation initiatives with the city. That office has the capacity to convene other city agencies to address major environmental challenges — a rarity in city governments, McPhearson added.

New York City commissioned a study of its own stormwater resiliency after seeing the devastating effects of Hurricane Harvey’s torrential rainfall on Houston, Texas, and it’s now working on a flood vulnerability study. But on the ground, the reality is that New York City’s infrastructure is nowhere near able to withstand the kind of rainfall it saw on Friday. The subway system is old and porous; the sewage system is, too.

Much of the city’s infrastructure needs to be rethought in order to deal with the kinds of climate vulnerabilities New York will face in the coming decade; sidewalks need to be raised to keep water from flooding from the roads into people’s homes, and subway grates need to be covered and pipes replaced. All of that takes monumental political will and effort — as well as billions of dollars, McPhearson said.

“This is at least a 10-year, if not a 20-year effort, to retrofit the city to increase its ability to absorb a lot more water. And it’s also anywhere between a $100 to $200 billion sewer system upgrade project,” McPhearson said. “Nobody knows where that money’s going to come from. Even with all the [Inflation Reduction Act] spending, there’s just no real source of the kinds of funding that would be required to make those kinds of upgrades; we’re only going to get that money from federal sources.”

Mitigation projects need to happen faster because it’s only going to get worse

As Vox’s Zhou pointed out, the impact of rainfall will be more intense as global temperatures increase:

“As the Earth gets warmer, the atmosphere is able to hold more water, leading to heavier precipitation when it rains, and a greater likelihood of flooding as a result. A 1 degree centigrade increase in the atmosphere’s temperature corresponds to a 7 percent increase in water vapor that it’s able to hold, according to the Center for Climate and Energy Solutions. And estimates suggest global temperatures could breach a 1.5 degree Celsius increase threshold sometime in the 2030s, meaning much more rain to come.”

Weather events like Friday’s are going to cause much more damage to places like New York City unless and until we learn to “live with water,” as McPhearson put it, which requires political, financial, and social mobilization on a significant scale.

Utilizing nature-based solutions, like infrastructure-supported soil and green space on the flat roofs of city buildings, for example, can help trap rainwater until it can be more safely and slowly released. And in cities like Rotterdam and Copenhagen, public space has been reimagined as part of a climate mitigation plan while still serving its original purpose. Copenhagen’s Enghaveparken — the “climate park” — was retrofitted to become a rainwater reservoir in case of a major rainfall event of the kind that hit the city in 2010 and 2011 and caused about $1 billion worth of damage.

But to be prepared for future storms requires a massive political, financial, and time investment, as well as the understanding that the “new abnormal,” as Mann put it, is happening right now.

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