The Regional Plan Association is calling on the city to rapidly upgrade its plans to trap stormwater runoff, in part by seizing street parking spots to build out more green infrastructure.

In a report released Monday morning, RPA planners made a series of recommendations to stave off the worst effects of future storms in a vulnerable section of Queens that was pummeled during the aftermath of Hurricane Ida. They estimated if the city boosted the types of green infrastructure and permeable surfaces that trap excess rainwater on publicly owned land by 40 times, it could prevent the type of damaging flooding that inundated thousands of homes and killed 11 basement tenants last September.

Part of the fix calls for usurping parts of public roadways and parking spots to convert them into additional types of green infrastructure — such as rain gardens, green streets that break up paved roads with verdant medians, and permeable pavement — to trap excess rainwater.

“We need to just challenge that prioritization of vehicles,” said Marcel Negret, a senior planner at the RPA, who co-authored the report. “Most of this space is taken up by cars and it's free parking … If we want to prioritize our needs for climate adaptation, we need to be more creative in using this very important space.”

Most of this space is taken up by cars and it's free parking … If we want to prioritize our needs for climate adaptation, we need to be more creative in using this very important space.

Marcel Negret, senior planner at the RPA

The report looked at parts of central Queens, including the neighborhoods of Jackson Heights, Corona, Elmhurst, East Elmhurst and Rego Park, where raw sewage and rainwater all flow to the Bowery Bay Water Treatment Plant and where some of the worst flooding occurred during Ida. The group identified 718 acres of sidewalks and 1,600 acres of roadways, throughout which existing and forthcoming green infrastructure accounts for just 3 acres of land, or less than 2% of the entire area.

If the city increased this by 40 times, up to 120 acres, or 5% of the total area, it might have avoided the kind of catastrophic flooding that caused tens of millions of dollars of damage, the report suggests.

Edward Timbers, a spokesperson for the Department of Environmental Protection, threw cold water on some of the RPA’s findings, saying locating new spots for green infrastructure is complicated due to existing components of the roadway like bus stops, fire hydrants and street lights, as well as underground water, gas, electric and sewer lines. The city has already fallen behind in its existing timeline for creation of new green infrastructure due to problems finding appropriate locations, Timbers said.

At last count, the city was about 30% of the way toward its goal of being able to capture 1.7 billion gallons of rain a year by 2030. It should have surpassed 40% two years ago, according to a timeline laid out in 2010.

Despite the delay, Timbers pointed to the more than 11,000 pieces of green infrastructure built or planned in recent years.

“RPA has put together a thoughtful report and we are encouraged that they and many others are getting behind our Green Infrastructure Program that is already the largest and most aggressive in the country,” Timbers said in an emailed statement. “We look forward to sharing ideas as we continue to advance a multilayered approach to stormwater management in NYC.”

But RPA planners say all of that green infrastructure is based on an outdated goal set more than a decade ago. The 2010 plan, crafted under the Bloomberg administration, called for the creation of enough green infrastructure to capture the first inch of rainfall from 10% of the city’s impervious surfaces by 2030, or the capacity to trap 1.7 billion gallons a year. That goal isn’t enough to keep up given the more severe storms expected as the climate warms. Ida, for example, dumped a record-breaking 3.15 inches of rain on the city in a single hour.

“We have to be more ambitious,” Negret said. “[We] should be handling much more than just the first inch of water.”

Timbers said the city was in the process of revising its stormwater goals and added that green infrastructure is just one way the city is managing it. He pointed to a recent rule change earlier this year that requires new developments to trap larger amounts of stormwater on their properties, and the city’s recently published Rainfall Ready NYC Action Plan, which outlines emergency preparedness for heavy downpours.