Original builders designed New York City’s infrastructure for a climate that no longer exists. When Hurricane Ida struck in September 2021, the city’s sewers could not handle the intense rainfall.
City planners designed the sewers to manage 1.75 inches of rain per hour, but Hurricane Ida delivered over 3 inches in just 60 minutes. This event marked the city’s first-ever flash flood emergency. The flooding killed eleven people in basement apartments—the only housing that poor immigrants could afford.
Their exits were blocked, and water rose too quickly for them to escape. Climate scientists and city planners now warn that Hurricane Ida may have been just a preview of even more severe storms to come.
Storms Getting Stronger, Natural Defences Disappearing
Atlantic hurricanes are becoming more dangerous every year. Between 2019 and 2023, approximately 80% of Atlantic hurricanes intensified more than scientists had expected.
These storms increased their wind speeds by an average of 18 miles per hour. In 2024, every single tropical storm gained extra power from warming ocean waters. Some storms increased their intensity by 10 to 14 miles per hour on top of their baseline strength.
These are not small changes—they transform weak storms into major threats for cities packed with millions of people. Meanwhile, New York City itself has lost nearly all of its natural protections. The city destroyed 99% of its freshwater wetlands and 86% of its coastal wetlands over the past two centuries.
These ecosystems once absorbed floodwater and filtered storm surge. Today, water floods streets, basements, and subway tunnels with almost no resistance. High-tide flooding in lower Manhattan has more than doubled since 2000, occurring 10 to 15 times every year now.
Sea levels have risen over one foot since 1900, and scientists project another 14 to 19 inches of rise by the 2050s. Heavy rainfall is becoming more extreme. Experts predict the share of rainfall from severe storms will increase from 41% to 47% by mid-century. These problems feed into each other, creating a cascading vulnerability that makes the city increasingly fragile.
The Race Against Time: Solutions Falling Far Behind
In November 2025, First Street Foundation released a climate risk model showing what a worst-case hurricane could do to New York City. Imagine a Category 1 hurricane striking New Jersey at high tide, bringing 4 inches of rain per hour and a 16-foot storm surge.
This scenario would flood 25% of the city and trap over 2 million people in Brooklyn, Staten Island, and Queens. Damage could exceed $20 billion. The MTA operates 13 of 24 subway yards that are prone to flooding during storms. Hurricane Ida flooded 45 subway stations and shut down 11 lines, resulting in millions of dollars in cleanup costs.
The problem is structural: subway drains connect to city sewers. When heavy rain fills the sewers, water backs up into tunnels faster than pumps can drain it. Today, only 6% of the city’s 472 stations have flood protection measures in place. The city is working to address these issues.
The MTA is spending $700 million over five years to protect subways by raising station entrances, upgrading 250 pump stations, and reinforcing walls. Mayor Adams announced a $390 million plan for Brooklyn’s Bushwick neighbourhood, which will replace three miles of old sewers and boost drain capacity by 850% in that zone.
But these efforts are tiny compared to the need. New York spends approximately $1 billion annually on its sewer and storm drain systems. Full upgrades would cost $30 billion. At the current pace, the work will not finish until 2055.
NYC’s environmental chief, Commissioner Rohit Aggarwala, stated bluntly: “We have an infrastructure that was designed for an environment we no longer live in. It’s as if New York City moved 500 miles south.” Dr Jeremy Porter, who leads First Street’s climate work, warns that the worst-case hurricane scenario will become increasingly common as our climate evolves.
Sources
New York Times, November 25, 2025
First Street Foundation Climate Risk Assessment, 2024
AM NY, July 22, 2025
Real Estate Climate Impact Report, 2025
ENR, July 21, 2025
Smart Water Magazine, March 2, 2025