The city administration asked people on Friday to stay home if possible – many subways were no longer running or experiencing long delays. Governor Kathy Hochul declared a state of emergency.
Deep varnish has formed on many streets and sidewalks among Manhattan’s urban canyons, as well as in Brooklyn and Queens. Videos also showed buses being flooded while driving, and underpasses on bridges such as those in Central Park were also impassable. Many New Yorkers remembered the heavy rains that flooded the city two years ago as a result of Hurricane Ida.
At that time, at least eleven people died because their basement apartments were full. Hochul also called the extreme weather a “life-threatening event.” A persistent area of low pressure that emerged from Tropical Storm Ophelia was responsible for the masses of water. But the metropolis’ infrastructure also played a role, according to reports in the “New York Times” (“NYT”).
Climate extremes and climate crisis
While individual extreme events cannot be directly attributed to a specific cause, one thing is clear, according to the current IPCC report: the climate crisis is making extreme weather events such as floods, storms and heat more frequent and more intense. This means that precipitation and storms are getting stronger, heat waves are getting hotter, and droughts are getting drier.
Infrastructure cannot keep up with climate change
All drainage systems would have their limits – and New York City’s has 4.45 centimeters of rain per hour. The storm that hit the region on Friday brought more than 12 centimeters of rain. In just a few hours it rained more than usual in a month.
Most likely, this will not be the last flood in the city, which is expected to accompany climate change. “The sad reality is that our climate is changing faster than our infrastructure can respond,” said the NYT, citing Rohit Aggarwala, commissioner of the New York City Department of Environmental Protection.
The torrential rain, which occurred during rush hour on Friday, overwhelmed the nearly 12,000 kilometers of pipes that carry stormwater and sewage under the city to wastewater treatment plants or the nearest rivers and bays, according to the NYT. Sewage reportedly accumulated in the streets and subsequently caused flooding, submerging cars and entering basements and subway stations in Brooklyn and Queens.
AP/Jake Offenhartz Flooding occurred in New York City as a result of heavy rain
Delays as a result
“We are in a new zone where we are experiencing higher intensity rainfall like this,” said former climate policy advisor to the mayor of Columbia University, Daniel A. Zarrilli, according to the NYT. “When the capacity of the sewers is exceeded, these backflows occur. If the pipes can’t handle this, backflow occurs.”
About 60% of New York City has a sewer system that combines stormwater and wastewater in the same pipes. If the flow through these pipes is more than twice what wastewater treatment plants can handle, the excess would flow directly into local waterways such as Brooklyn’s Gowanus Canal, the East River and Jamaica Bay.
picturedesk.com/EPA/Justin Lane A New York sewage treatment plant
But when the sewer system comes back online, some of the raw sewage ends up in the basements of homes and businesses across the city, according to the operator of a water maintenance service in Queens. “That’s when normal people start to have water coming out of the sewers or basement toilets.” On Friday, his company received “a lot of calls” from desperate homeowners that he couldn’t do anything for.
Hurricane “Sandy” as a scandalous warning sign
Hurricane Sandy, in October 2012, should have been a warning to New York authorities about climate and meteorological risks, writes the North American news agency NBC. “Sandy” caused a catastrophic storm off the coast of New York and New Jersey.
The storm left two million New Yorkers without power, killed 43 residents and damaged or destroyed nearly 70,000 homes. The extreme weather phenomenon caused damage worth around 19 billion dollars (17.9 billion euros) in New York City.
Since then, not enough progress has been made in protecting New York City from climate risks, according to the city controller’s office. “Nearly a decade after Superstorm Sandy and six months after Hurricane Ida, we have not done enough to prepare for future storms,” Auditor General Louise Yeung told the City Council in April 2022. “Meanwhile, our decades-old infrastructure of existence continues to age.”