On Wednesday, New Yorker Kaye Blegvad was stymied in her attempt to board the G train at Broadway Station in Williamsburg.
The entrance and stairs to the subway platform at the corner of Broadway and Union Avenue were completely underwater, and there wasn’t a rain cloud in sight.
“The other subway entrances were dry and normal and nobody seemed to be freaking out, so I just got on the train,” Blegvad told Quartz. “Only once I was on the train did I start thinking, wait, that really was quite insane.”
Later that afternoon, she posted a picture of her curious subway encounter on Twitter and asked the NYC Metropolitan Transit Authority (MTA) to “explain themselves.”
The NYCT Subway Twitter account, which provides 24/7 live updates about MTA service, clapped back: “we’re pivoting to submarines.”
All joking aside, the MTA quickly followed up with another tweet that indicated it had purposefully flooded the station for four hours to test the installation of a new flex gate — a type of barrier that can hold back 14 feet of water in the event of a flood or rising waters during a superstorm or hurricane.
“We’re doing this because climate change is real,” the MTA said.
In October 2012, storm surge from Superstorm Sandy completely flooded nine subway tubes with saltwater and submerged two Long Island Rail Road tubes linking Manhattan with Queens.
The damages from Sandy are still being repaired, even as the MTA tries to prepare for future storms to the tune of $5 billion.
Preparing for the next superstorm
Seven years ago, Hurricane Sandy spawned over the north Atlantic and hit Category 3 status, with winds reaching 130 mph. By the time it made landfall in New York and New Jersey, it had weakened to a superstorm that spanned 1,000 miles across.
With Sandy, it wasn’t hurricane-force winds that wreaked havoc in the Big Apple, but the resulting storm surge. The sea level rose far above the tide line, and floodwaters reached nearly 8 feet in parts of the Jersey Shore and 6.5 feet around New York City. It readily swamped underground subway platforms and tunnels.
At the time, the MTA could only bring sandbags and plywood to shore-up vulnerable subway openings.
“We’ve learned our lesson … won’t happen again,” former MTA Chairman Joe Lhota said in an interview after the superstorm.
In the year since Sandy, the MTA has put several solutions in place to prepare for the next superstorm.
These protections include 3,000-pound, vault-like doors that can board up stations closest to the waterline, like those at Whitehall Street and South Ferry in downtown Manhattan. The MTA also has a system of interlocking flood logs that can be stacked at subway entrances and heavy fabric curtains that can block water. More than 2,000 covers are in place to shore-up subway grates.
The flex gates, like the one being tested at Broadway Station in Williamsburg, are made of Kevlar. They’re light enough so that a single person can install the flood barrier in minutes. 65 of them have been installed in the city so far.
The MTA tweeted that the gates are designed to fully “seal off a subway entrance.” The organization also told The Verge there will be more “flood tests” like the one that took place Wednesday in the future.
“We’re investing in capital projects around the system to prepare for the impacts of a changing climate,” the account tweeted.
Hurricanes are becoming stronger, wetter, and more destructive
And the MTA isn’t kidding itself about what the future will bring to New York.
Its website notes that “with intense weather events like Superstorm Sandy expected to occur more often, we need to act now to protect this vital part of our system, so we can keep trains running safely.”
According to a recent study, extremely destructive storms like Sandy and Katrina have gotten far more common in the US relative to their less damaging counterparts.
“We estimate that there has been a tripling in the rate of the most damaging storms over the last century,” Aslak Grinsted, the lead author of that study, previously told Business Insider.
While scientists can’t directly link individuals storms like Sandy to climate change, warming overall makes such storms and hurricanes more frequent and stronger than they would otherwise be.
That’s because oceans absorb 93% of the extra heat that greenhouse gases trap in the atmosphere, and hurricanes use warm water as fuel. So a 1-degree Fahrenheit rise in ocean temperature can increase a storm’s wind speed by 15 to 20 miles per hour, according to Yale Climate Connections.
Plus, rising water temperatures lead to sea-level rise, which increases the risk of flooding during high tides and in the event of storm surges. Warmer air also holds more atmospheric water vapor, which enables tropical storms to strengthen and unleash more precipitation.
Generally, a stronger storm brings a higher storm surge. This resulting wall of water can flood coastal cities, as Sandy did in 2012. If a storm’s winds are blowing directly toward the shore and the tide is high, storm surges can force water levels to rise as rapidly as a few feet per minute.
But deployment tests like the one Blegvad saw in Williamsburg this week may ensure that future storm surges don’t cause the same level of damage as they did during Sandy.
“I am confident that the MTA is more prepared than ever to face storms even stronger than Sandy,” Lhota said in a recent MTA press release.