It’s become a regular occurrence here in New York City: A powerful rainstorm overwhelms the city’s infrastructure, causing flood damage and sometimes deaths — all because of an antiquated sewer system that was never designed to hold so much water at once.

But what if the rainfall had somewhere else to go?

“This water is actually being held underneath the park,” said Amy Chester, explaining the concept behind Southwest Park in Hoboken, N.J.

It’s one of a series of new parks that can cumulatively hold more than 4 million gallons of rain, in part using underground pumps that bring the stormwater to huge storage tanks below ground.

The water is then slowly released into the city’s sewer system.

“It’s not that our sewers don’t work [in New York],” Chester said. “It’s that they don’t work for the massive amount of rain that we get all at the same time. So this spreads it out over time.”

Chester is the director of Rebuild by Design, an NYU-based organization formed after Hurricane Sandy that helped develop a comprehensive resiliency plan for Hoboken.

The new parks also feature permeable pavement and other infrastructure that keeps athletic fields and other areas dry during heavy rain. At Northwest Resiliency Park, water is directed to low-lying areas, including a basketball court that actually acts as a catch basin.

During heavy rainfall, the court “actually stores the water,” she said. “It’s supposed to flood.”

Parkgoers may be unaware these parks provide more than just green space; they can also save lives.

“You can start thinking about how these parks could play double, triple, quadruple duty,” Chester said. “It’s social infrastructure, and it’s physical infrastructure that is keeping the surrounding neighborhood dry.”

“What’s been done in Hoboken is a great model,” said Queens City Councilman Shekar Krishnan, chair of the Council’s parks committee. He says the city needs these types of big, bold ideas — regardless of the price tag.

“For me, the question of, ‘Is it feasible?’ ‘Is it not?’ — the amount of money will it take — that’s not a question,” he said. “It’s a necessity.”

Rebuild by Design found almost 70% of the city’s parks will be in a flood zone by the year 2100, up from 38% currently.

“Yes, it will cost billions,” to follow this model in the five boroughs, Chester said. “But we’re going to be spending billions of dollars on our flood infrastructure no matter what. But there’s a question: Do we want to do it through hard infrastructure and seawalls? Or would you want to do it through reimagining our neighborhoods to be places that we want to live and work and play?”