April showers bring May flowers -- and floods

Over the years, torrential rains have resulted in dangerous flooding problems from Riverdale to Kingsbridge and beyond. In 2021, 2022 and 2024 heavy downpours left drivers stranded along the Major Deegan Expressway and problems that never plagued the streets of NYC -- like drowning deaths -- became a new concern.

As a result, city agencies and legislators began exploring solutions to protect residents during storms.

Introduced by Councilwoman Selvena N. Brooks-Powers in April 2024, Bill 807 was discussed at a City Council meeting earlier this year and sought to establish shelters before a flash flood event in at least 10 neighborhoods. Qualifications depend on the area’s history of flooding, the presence of vulnerable populations and the number of basement apartments and other subgrade dwellings. 

However, Heather Roiter, deputy commissioner of planning and resiliency at the New York City Emergency Management Department, warned about the “impracticality” of the program. 

“Advisories and flash flood warnings are issued only an hour or so in advance or in some cases, as the storm is ongoing,” she said. 

While weather forecasting models have made progressive strides in the past 30 years, capable of predicting where a storm will occur up to five to seven days in advance, the models for predicting how much water will fall, which neighborhoods will be affected and how it will be distributed throughout the city, are not yet advanced enough to say with certainty what neighborhoods will be safe, explained James F. Booth, deputy chair of the Earth and Atmospheric Sciences Department at the City University of New York.

“We’re moving in that direction, but for right now it’s not there,” he said.

Booth estimates around 10 years of data would be needed to capture a wide variety of storm types, which could help to optimize the city's Department of Environmental Protection flood models, improving flood predictions and management across the city. However, Booth is concerned about potential budget cuts to the program, especially given the broader reductions in science funding under the Trump’s administration.

Since 2020, NYC has partnered with researchers from CUNY and NYU in the FloodNet program, a network of real-time flood sensors. The system is designed to provide hyperlocal, real-time flood data to improve response efforts and inform long-term resilience planning.

According to Sherida E. Paulsen, chair of the board at the Riverdale Nature Preservancy, residents across the greater Riverdale area have raised concerns about flooding to the community board, citing the intersection at Kappock Street and Palisade Avenue as a concern.

“If we're getting more severe storms with faster, harder rainfall in a short period of time [floods will increase] and that's what we're seeing, stronger storms,” Paulsen told The Press.

It remains unclear whether Bill 807 will be approved or if Riverdale will be among the neighborhoods chosen to participate in the pilot program. Although the neighborhood has been repeatedly impacted by heavy rain flooding from backed up drains and pipes, causing property damage, there are boroughs, like those in Queens, that have seen more dire consequences.

“When it comes to weather events, it's all hands on deck.  That means addressing the immediate need with legislation like this with emergency shelters for those in physical danger,” Dinowitz added. 

In the meantime, the city’s Emergency Management Department has initiatives in place to protect residents in vulnerable neighborhoods, such as the Notify NYC program, the use of social media as an advanced warning system and flood alarms in basements. 

Booth cautioned that with measures that focus on being over-prepared, risk communication must be clear and balanced to maintain public trust in science. If a forecast predicts a significant impact from rainfall but the outcome is less severe, it doesn’t mean the science is unreliable or that future forecasts will be inaccurate. 

If the bill passes, it’s estimated to cost $36 million over four years starting in 2026. Moreover, it highlights the critical need to continue investing in the science of predictive models which would provide more detailed guidance, beyond the general information currently available, Booth explained. 

“The idea behind the bill is smart. It’s about resilience for a hazard,” Booth said. “The challenge is that we need a balance between setting up such resilience and the reality about what we have certainty and uncertainty about.”

A representative from FloodNet will speak at Riverdale Nature Preservancy’s annual meeting on April 29 hosted at the Riverdale Country School at 7:30 p.m. The meeting is open to the public and will discuss problem flood areas.