Yves here. This New York City study examines what not just global warming water rises but also increased periodic flood damage means for entire neighborhoods, not just residences and commercial properties but also critical infrastructure like subway lines and electrical substations. After Hurricane Sandy, Manhattan had a blackout zone that started just below 34th Street. And unlike where I live, where power outages are common enough that elevators have backup generators, I knew of only one person, the famed Nathan Tankus, who lived in a complex with backup power.
The big point is that this look at New York City’s future is indicative of what is in store for many other global cities.
By Samantha Maldonado, a senior reporter for THE CITY, where she covers climate, resiliency, housing and development. Originally published at THE CITY on April 1, 2026
Peering at New York City’s landscape more than 400 years in the past — when the marshes, ponds and streams crisscrossed our string of islands — can help planners and policymakers better understand the city’s flooding future.
Researchers at the New York Botanical Garden looked at where water used to be, where there’s water now and where — thanks to climate change — water will be in the coming years. Those places are called Blue Zones.
The five boroughs contain more than 500 of them, according to a new paper published Wednesday in the Annals of the New York Academy of Sciences, the first comprehensive analysis of its kind. The Blue Zones cover more than one-fifth of New York’s land.
“Everybody was startled, including us, that it’s more than 20% of the city,” said Eric Sanderson, vice president of urban conservation at the New York Botanical Garden and an author of the paper. “That combination, you can’t really argue with it — places that were wet, are wet and will be wet in the future.”
Lucinda Royte, lead author of the paper and manager of urban conservation, data tools and outreach at the New York Botanical Garden, said the Blue Zones indicate where it’s most pressing to address flood risks and increase resiliency.
“It can be a pretty good guide about where we’ll see flooding in the future as a result of coastal flooding from storm surge and sea level rise, and inland flooding from rainfall events,” Royte said. “It can help us plan a little bit better about where we need to make some infrastructural changes in the city before a flooding crisis happens.”
About 1.2 million people (about 12% of the city’s population) and 11% of buildings are in Blue Zones. With the report, the Botanical Garden launched a digital tool that shows block-by-block information about historical ecology, current flood vulnerability and future flood risks.
Both LaGuardia Airport and JFK Airport are located in Blue Zones, on former salt marshes and marine ecosystems that were filled in. About a third of public housing developments, home to some of the poorest New Yorkers, are in Blue Zones, too.
Royte herself lives in a Blue Zone: Gowanus, Brooklyn, which was historically a salt marsh with Gowanus Creek flowing through. The concept of Blue Zones hit home for her when Hurricane Ida brought floodwaters to her neighborhood.
“My entire block was underwater,” she said. “I saw ponds and streams and wetlands return.”
Notably, the paper notes that some of the Blue Zones will become inhabitable in the future, which points to the urgent need to build more housing, transit and other services elsewhere in the city — a conclusion other studies have made.
‘Water Doesn’t Care’
Blue Zones raise a red flag about the scale of the flood problem New York City faces, and will face, thanks to climate change, which promises to bring higher seas, more intense storms and more rainfall in the coming years.
“It shows how large scale this is and it lets you look at the city as a landscape,” Royte said. “We currently view the city through its political boundaries. We care about neighborhoods and zip codes, but water doesn’t care about those boundaries.”
Of the Blue Zones, nearly two-thirds of the land area is at risk of coastal flooding from storm surge and sea level rise. About 5% of the Blue Zone land is at risk of flooding from rainfall, and 36% could see both coastal and rainfall flooding.
Much of the land in the Blue Zones is public, with government entities owning about two-thirds and the Department of Parks and Recreation specifically overseeing half of that.
“It’s so obvious that investing in parks will save lives and livelihoods,” said Amy Chester, director of Rebuild By Design, who reviewed the Blue Zones paper. Her organization last year released an analysis showing a majority of city parks will be at risk of flooding.
The Parks Department — whose proposed budget falls short of what Mayor Zohran Mamdani had promised — acknowledged its role in flood management.
“By working together and integrating the latest data and best practices into our planning process, we can create a stronger, more equitable park system that protects both people and nature for generations to come,” Parks spokesperson Judd Faulkner said in a statement.
In a statement, DEP spokesperson Doug Auer called the Blue Zones analysis “a useful tool in our collaborative stormwater planning efforts,” and pointed to work the agency is doing with other agencies to “identify where public lands can serve double duty for stormwater management and help restore natural urban drainage corridors.”
Many of the initiatives to make neighborhoods more resilient to flooding — including permanently moving people away from risks, adding storm drains and building rain gardens — are in the works, prompted by disastrous flooding after 2012’s Hurricane Sandy and 2021’s Hurricane Ida.
“We found, coincidentally, when you look at places that flooded during Hurricane Sandy or Hurricane Ida, they line up pretty closely with historical hydrology,” Royte said.
The storm surge of Sandy flooded areas that had been beaches and tidal marshes, while Ida’s deluge flooded places that had been ancient ponds, wetlands and streams.
Residents of Hollis, Queens, dealt with devastating flooding during Ida as well as during many other rainstorms, and learned their lowlying neighborhood was built atop a former pond.
The Hole, a neighborhood on the border of Queens and Brooklyn that sits below sea level, has continuously taken on water that can remain days after it rains. The city is now offering possible buyouts to residents there.
In The Bronx, the city is also working to unearth Tibbetts Brook in order to bring the subterranean waterway above ground, as it was over a century ago. That way, the brook can once again channel water, preventing it from hitting the sewer system and surrounding areas.
But Sanderson said more must be done: “I don’t think there’s any choice but to scale up. The climate is going to force our hand, and we’re already seeing that,” he said.
“You can use planning and ecosystems to help return some of that water to the sky and some to the ground and not assume all has to go through the wastewater treatment plants.”
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Not even bringing in the federal level, the relationship between the upstate-downsate, tri-state local/state governments are so dysfunctional (eg, MTA), there is no hope of any preventative measures or regional disaster readiness. IMO.
NYC definitely going to slam into the wall at full speed on this one. Don’t count on the cavalry to rescue you in the first 24 hours of a flooding event.
Not sure where Mr. Tankus lived, but there were buildings on 27th and Tenth that had power. It is a protected and controlled co-op with a waiting list to get in because it was built by unions designed for lower incomes and houses retirees as well as other working class people. It had generators that kicked in. (Still waiting for a possible unit after applying well over a decade ago. )
I’m going to have to check the new maps. Pretty sure I am fine (even if my neighborhood was the last Manhattan one to get power back after Sandy). The place where I work…that’s iffier.
Correct. It’s an entire complex, with a VERY long waiting list which sells the units at some sort of controlled prices and comparatively low down payments.
It is a lovely model for affordable living. And it should be looked at far more often than it is. But it won’t be because it doesn’t provide enough profit for most of the profit sector in public profit financing.
It’s Penn South you’re talking about, no?
It was built by the garment workers union as non-profit cooperatives for working people, since it’s set just south of what was once the city’s largest employer, the garment industry.
Interestingly, and to the great credit of the residents, a referendum to turn the complex into market-rate coops was defeated years ago, so it remains home to many middle income New Yorkers. Also, and partially as a result of its wonderful location and affordability, it has become a NORC (Naturally Occurring Retirement Community).
We have similar issues here in the San Francisco bay area where some 30 to 40 percent of the bay has been filled in and built up.
Where I live, a significant portion of our primarily residential island city of Alameda off the coast of Oakland also consists of landfill.
Alameda does have an unfortunate history of race based redlining as well as successful voter opposition to new construction. The latter being motivated by what could be termed quality of life issues. Specifically, before voters largely put an end to it, there was a time when Victorians, Craftsman and other older single family dwellings were being demolished and replaced by “little boxes made of ticky-tacky
and they all look just the same.”
This changed a number of years ago when the state essentially strongarmed Alameda and other local jurisdictions into greenlighting significant residential construction projects in order to address the greater bay area’s unmet housing needs.
Given that here in Alameda, the new housing was being constructed on low-lying shoreline landfill sites, some of us accused the government, in collusion with developers, of selling “quicksand futures.”
Lo and behold, now just a few years later, while the developers have come and gone, taking their profits with them, it would appear that tax payers are going to be on the hook for protecting homes that many of us feel should not have been built in the first place.
Water Siege in Alameda: Island City Braces for Floods From Above and Below hoodline
Check out Boston. Prolly way more reclaimed land then NYC.
houston sits in a swamp.with a giant water-collecting prairie to the west.and the bays, galveston and trinity, act as funnels for storm surges…leading right into downtown, and right through a buncha industrial and logistics stuff east of town.
my brother and cousins live on the outer northern edge of all that urbia.
and where i grew up, between magnolia and conroe, used to be just woods and small farms…now is unrecogniseable. whole subdivisions built in the Lake Creek watershed(ahem, its called ‘lake creek” for good reason).
all the smaller cities along the texas coast are just as bad, of course…just smaller and with far fewer people.
decades ago, i was on the seawall in galveston for a hurricane party…dude i knew owned a bar, and i went down to help board it up, etc…and stayed with them and a buncha others during what turned out to be a mere tropical storm. wild coupla days, there,lol.
ive also been in algiers and west lake charles and houma and morgan city , in louisiana, during tropical storms…never a hurricane.
the problem there is what the corps have done over the last century,lol….with priorrity laser focused on industrial infrastructure protection..as well as what the oil people have done to the once protective barriers of estuaries and marsh and swamp. in the atchafalaya basin, 35 years ago, there were like watery highways cut through the cypress and tupelo jungle, straight as an arrow. my swamp people friends would rail about these, because they funneled wind and water to where it never used to go. same with that spillway north ow new orleans, which dumps excess mississippi water right into the basin(river used to flow there, long ago)
This all reminds me of Kim Stanley Robinson’s book “New York 2140” where in that time lower Manhattan is under water and much of the rest is like present day Venice, complete with Gondalas moving up and down 5th Avenue. It is also well worth reading
I lived on the Upper West from 2008 to 2024.
For those who are not familiar, when you move uptown along Manhattan’s West Side, initially the terrain is fairly flat. But by the 50s-60s (street-wise), you get this pronounced rise, where 10th Avenue sits uphill of 11th Avenue, with the vertical distance at least 50 feet in places. Consequently, West Side Highway to 11th Avenue has always been an “orange” flood zone, while 10th Avenue and areas east are not.
Whether for this or for some other reasons, back in the 1980s and 1990s when they were developing Upper West, they built the new buildings east of 10th Avenue. I lived in two of those, both 1980s vintage. And when I’d moved into Building 1, which looked out West towards the Hudson, between here and there, i.e. past 10th, there were only a few 20-30-ish story high rises and the rest mostly old, pre-war or 1960s type buildings.
Within a decade, that entire landscape had changed, to the point where I did not have anything resembling a view of the Hudson anymore. Reams, sheafs, metric megatons of 50+ story modern skyscrapers, primarily residential (!!), with more on the way. High priced housing, I stress this, being built out from 11th Avenue westward towards West Side Highway. It’s not just up there, something similar has been happening to the area around Javitz more recently (west 30s), half the old prewar low-rise buildings are gone and new (high priced) construction almost runs up to the river.
I was joking back then that all it would take is one good flood to drop the property or rental prices to where mere mortals like myself could actually afford it. To be sure, during Sandy (2012) the surge did not get there, I could see traffic on 11th Avenue from my window the whole time. But my broader point is that a big part of Manhattan development over the past now 20 years has been putting, I underscore, high priced appartments by the thousands in previously “poor-ish” areas, many of which just happen to have already been designated “orange” or “red” flood risk zones. But since we haven’t actually had a flood of any consequence in Manhattan (Sandy devastated mostly Staten Island and the southern edge of Brooklyn and Queens), no-one knows, no-one cares.
I don’t care much either – not my problem, especially now that I’ve been squeezed out of Manhattan (and my neighborhood should, for the most part, be safe, though there are some former gulleys nearby that could take a hit). But my point is someone is going to be in for a rude awakening, either through a catastrophic event, or, also possible, a decade or two worth of gradual escalation of the problem (e.g. through the sea level rise).