NYC flood plan includes alert for basement dwellers — but not ‘til 2023
City officials were well aware of the death traps that basement apartments would become in the event of a flash-flood emergency like the one that drowned at least eight New Yorkers living below grade Wednesday night — yet they did nothing to warn them.
Mayor Bill de Blasio’s Stormwater Resiliency Plan, released in May, includes an initiative that would “develop notifications for basement dwellings to keep residents out of harm’s way.”
The plan required the Office of Emergency Management to “pre-draft messaging regarding potential dangers for residents living in basement dwellings to be used for outreach and notification in advance of forecasted extreme rain events.”
Completion date? 2023.
“There are multiple initiatives, all that are very pressing and important, that are currently underway,” City Hall spokesman Mitch Schwartz said.
The city’s Department of Environmental Protection is well aware of pervasive flooding problems.
“DEP’s Bureau of Water and Sewer Operations (BWSO) is responsible for maintaining NYC’s sewer networks in good working order and addressing problems as they arise,” the plan says.
“BWSO addresses hundreds of sewer-related 311 complaints each year and activated its flash flood emergency plan 35 times in 2020 alone,” it states.
The document unwittingly highlights a potential reason that catch basins aren’t well maintained, causing water to pool on streets and then pour into homes.
No fewer than four different agencies are responsible for keeping them clear — the Departments of Environmental Protection, Sanitation, Transportation and the Office of Emergency Management.
Schwartz said “it’s a big job and they have different areas of expertise.”
Still, the de Blasio administration didn’t begin its Stormwater Resiliency Study — “to gain a fuller understanding of how more frequent and extreme rain events will affect the city” — until 2017, three years into the mayor’s first term and a decade after a 2007 tempest flooded major streets, crippled public transit and knocked out electricity to thousands of customers.
In that 2007 storm, just 1.7 inches of rain fell in Central Park in an hour — compared to 3.15 inches in one hour last night.
The 24-page plan notes the city’s sewer system can only handle 1.75 inches of rain per hour and projected that amount would increase to just 2.15 inches per hour, but not until 2040 to 2069.
The remnants of Hurricane Ida that hit the city Wednesday swamped that projection by one inch — and at least 19 years.
Schwartz said the report uses an “average storm” for modeling performed by Cornell University climate experts, not an “extreme event like yesterday’s.”
The document does describe an “extreme stormwater flood scenario” where 3.5 inches of rain would fall in an hour. It’s also referred to as “the 100-year storm, with a 1 percent chance of occurrence in any given year.”
The “strategic changes” detailed in the plan to prepare for a 100-year storm are scheduled for completion between 2021 and 2027– most well after de Blasio leaves office at the end of this year.
The mayor has already blown a spring 2021 deadline to amend the Uniformed Stormwater Rule to require developers of new projects to do more to prevent water runoff on their sites.
An administration spokesman attributed the delay to the coronavirus pandemic, and said the amendment would come this fall.
