You are here

"16-Foot Storm Surges, 500 Miles Of Coastline Flooded" Here's What A Category 5 Hurricane Would Do To NYC

Luckily for residents of New Jersey, New York and New England, Hurricane Jose isn’t expected to pass close enough to the northeastern US coast during its journey north through the Atlantic to cause any real damage.  While the National Hurricane Center has warned that the category one storm is expected to cause “dangerous surf and rip currents” along the east coast for a few more days, the region will thankfully be spared the devastation of Sandy, which battered areas with comparatively tame 80 mph winds. By comparison, Irma battered Puerto Rico with gusts of up to 135 mph.

However, the narrow miss – particularly given the sheer destruction wrought by Hurricanes so early in the season – has prompted some to wonder: What would happen if New York City had to face the worst possible scenario: A category 5 storm making landfall in the city.

According to Bloomberg, it’s unlikely that a hurricane would be able to maintain category 5 status while traveling that far north, given sea temperatures and weather patterns. But as the boundaries of what’s scientifically possible are constantly in flux, this reality is not out of the question.

Indeed, rising sea waters are forcing meteorologists and emergency managers to consider scenarios they once believed were improbable. The water level around New York is 1.1 feet higher today than in 1900 and could increase as much as 2 feet more by 2050.

“With global warming and sea-level rise, what we’re seeing is the effects of these storms amplified,” Ernest Moniz, energy secretary for President Barack Obama, told Bloomberg TV.

According to Bloomberg, a category 5 storm could pummel New York City with as much as 50 inches of rain. Winds of just 100 mph could create a 16-foot tall storm surge that would deluge 500 miles of NYC coastline.

“Winds of 100 mph and 12 inches of rain at high tide push a 16-foot storm surge through the funnel-like entrance of New York Harbor. It wouldn’t take Irma’s killer gusts or Houston’s torrential 50 inches of rain to create a wall of water swamping 500 miles of New York City coastline. The Hudson and East rivers would cascade into Manhattan, overwhelming subways, sewers and roads. Corrosive seawater would fill the aging Lincoln and Holland tunnels to New Jersey, as well as the vulnerable railway tubes beneath the Hudson.”

The potentially unprecedented devastation that could be brought by the storm makes the risks of such a scenario occurring worth reviewing, however unlikely scientists believe it to be.

http://www.zerohedge.com/sites/default/files/images/user245717/imageroot/2017/09/18/2017.09.19nycfloodmap.JPG

Such a storm could force almost half a million people from their homes and possibly change the face of New York City forever.

“The potential risks, however remote for now, are enormous for the New York metro area. Sandy, which hit New Jersey as a “post-tropical” storm, flooded almost 90,000 buildings, with 443,000 New Yorkers living in inundated areas. In one part of Staten Island, floodwaters reached 14 feet.

 

Bridges reopened quickly, but close to 2 million people lost power, and cell service for more than 1 million people was reduced or lost. Rebuilding is still going on five years later.”

Though the number of victims forced from homes could well be higher. More than 3 million New Yorkers now live in one of the city’s evacuation zones after the city revised them following Sandy. Megan Pribram, assistant commissioner for planning and preparedness at the city’s Office of Emergency Management, told Bloomberg that for a storm on the scale of Harvey, the city would evacuate some low-lying coastal areas.

Rainfall on par with the record 51 inches that Harvey dropped on Texas would be unprecedented for the Northeast. The most serious flooding in recent memory occurred during 2011, when Hurricane Irene pummeled the state with 15 inches of pain, leaving parts of Vermont under water.  

Harvey-sized rains would be unprecedented in the US. Northeast, according to Allan Frei, chairman of the geography department at Hunter College in Manhattan. The most serious flooding in the region was Hurricane Irene in 2011, when 15 or so inches of rain left parts of Vermont underwater.

Among the last two “major” hurricanes to hit New York City (remember, Superstorm Sandy was classified as a post-tropical depression) was a category 3 storm with winds up to 129 mph that struck in 1938. The “Long Island Express” caused 18-foot storm surges in parts of the city. Another category 3 storm, Hurricane Hazel, produced 113 mph gusts in Battery Park in 1954.

Combining a storm surge with unprecedented rainfall would quickly overwhelm the city’s sewer system, according to Bloomberg.

“If a storm causes a big storm surge at the same time as it’s raining, and if it hits during high tide, that would be - I can’t even imagine,” Frei said. The sewer system would probably be blocked with debris, diminishing its capacity to drain the city, he said.

Fortunately, the city is updating preparedness plans to incorporate the lessons of Harvey, said Daniel Zarrilli, senior director of climate policy and chief resilience officer for Mayor Bill de Blasio.

And tens of billions of dollars in Hurricane Sandy relief spending were used to improve the city’s infrastructure.

Hospitals and public-housing complexes have been refitted to offer more flood protection at a U.S. Federal Emergency Management Agency expense of more than $10 billion. Utility Consolidated Edison Inc. has spent $1 billion for upgrades to its underground steam, electric and gas infrastructure. A $340 million boardwalk in the Rockaways has been redesigned as a sea wall protecting beaches and homes. The city has planted trees and other vegetation in flood-prone neighborhoods to soak up runoff and ease the burden on the city’s sewer system.”

Meanwhile, the NY-NJ Metropolitan Storm Surge Working Group is pushing the Army Corps of Engineers to approve a $30 billion system of retractable sea barriers at the mouth of New York Harbor and in the Throgs Neck narrows north of the East River. Similar engineering projects now protect cities including New Orleans; Rotterdam, Holland, and St. Petersburg, Russia.

But even with those reinforcements, the city would remain vulnerable.

“We in New York are far behind, and among the cities on Earth we have the most to lose,” Yaro said.

New Yorkers should keep this in mind before buying property in the city – particularly if it’s located inside one of the city’s evacuation zones. Just because it hasn’t happened before, doesn’t mean it can’t happen.