On Friday, the New York Department of Environmental Protection (DEP) held an informational roundtable with the public to promote awareness regarding hurricanes and flood prevention. New York is increasingly under threat from heavier rainfall, as the National Oceanic and Atmospheric Administration has reclassified New York City as being in a “humid subtropical” climate. In just the last 3 years, the city has experienced multiple storms with unusually intense downpours. Hurricanes Henri and Ida in 2021 peaked at 1.94 and 3.15 inches of rain per hour respectively. To put that in perspective, an inch of rain amounts to roughly 10 inches of snow, and our sewer system can handle up to around 1.5 to 1.75 inches per hour. Hurricane Ida killed 46 people across the region, 13 of them in New York City. In the wake of the catastrophic hurricane Helene, which so far has claimed more than 200 lives across the southeast, NYC officials are getting the word out about what people can do to be as prepared as possible as the season continues.
Beth DeFalco, deputy commissioner for public affairs of the DEP, tells participants that the City is expecting “the worst hurricane season we’ve ever seen.” She notes the particular danger of storm surges coinciding with high tide, and urges her audience to take steps to plan for intense storms before they arrive in a variety of ways: downloading the NOAA app to keep up-to-date on how high the tide is at any given moment and see the current rate of inches of rain per hour; using the Notify NYC app to keep up to date information on the local situation, including the location of evacuation centers; buying flood sensors (“a fire alarm for water”) and placing them on the floor in the basement to be instantly alerted as soon as flooding starts; using sump pumps to remove water coming up from under a basement (City officials have distributing these at events); using flood barriers (basically sand bags but filled with water) and placing them outside of entryways where water could get in.
DeFalco also strongly discourages creating living spaces in basements, let alone whole dwellings. New York City’s sky-high rents and demand mean that many do resort to living in such spaces, and were indeed a large proportion of those killed by hurricane Ida.
For its part, the city is making what structural changes are possible in the context of an especially dense urban environment with its own particular challenges. Replacing or upgrading sewer systems is very time consuming and expensive, leaving officials to seek other options, like porous pavement, which allows water to seep through it and absorb into the ground below. Even this is no panacea though, as Manhattan sits on bedrock that would not allow for the water to absorb in most places on the island. DEP officials have also deployed 500 floodnet sensors across the city at a cost of around $7 million, which use lasers to measure flood depth in real time. The agency has also begun implementing “bluebelts,” a drainage system which, according to their website, “preserves natural drainage corridors including streams, ponds, and wetlands, and enhances them to perform their functions of conveying, storing, and filtering runoff precipitation or stormwater.”
The proactive stance from DEP officials is perhaps reassuring, but in a city that continues to attract more people and is already facing a housing crisis, there may be tougher choices ahead. Rit Aggarwal, NYC’s chief climate officer and Commissioner of the DEP, explains that as floods become more common and certain areas reveal themselves as more vulnerable than others, a voluntary buyout program “may make sense […] particularly to protect surrounding areas.” He understands the gravity of such a decision and insists that it is “an absolute last resort,” though also admitting that the option is being considered over the long run for “80 odd locations [that are] most flood prone.”
At the time of this writing, hurricane Kirk, a category 4 storm, is gathering strength in the Atlantic, where it is luckily expected to remain before dying out.
