Long Island roads ill-equipped for heavy rains, experts say

Long Island’s roadways — many of which were designed nearly a century ago — are not equipped to handle the increasing frequency and severity of major rainstorms and rising sea levels, climate and infrastructure experts said.

But better maintenance of existing drainage systems could lessen the impact of flooding events, like the one that inundated portions of Suffolk County last month with more than 9 inches of rain, they said.

Long Island climatologists said transportation infrastructure built during a time when Nassau and Suffolk were far less developed and populated will struggle to keep up with modern weather events. Much of the "natural sponge" that once covered much of Long Island has been replaced with "impermeable surfaces that can’t take in water," such as paved roads and parking lots, said Jase Bernhardt, an assistant professor at Hofstra University and the director of the school’s graduate sustainability program.

"Many decades of development have really weakened our ability to take in water at the surface, and makes us so much more vulnerable to flash flooding," said Bernhardt.

Putting further strain on Long Island’s roadway network is a changing climate, according to Bernhardt, who pointed to federal data showing sharp increases in "extreme precipitation" events in the Northeast over the last 70 years.

According to the National Climate Assessment published last year, from 1958 to 2018, the number of days with 2 or more inches of precipitation increased by 49%; 3 or more inches, 62%; 4 or more inches, 84%; 5 or more, 103%.

Without closer inspection, upkeep and modernization of the decades-old basins, culverts, outfalls, manholes and drainage pipes relied upon to collect rainfall and divert it away from Long Island roads and properties, catastrophic flooding events will persist and worsen, experts said.

"It’s devastating," said Marc Herbst, executive director of the Long Island Contractors Association, standing near the jagged edge of what’s left of Harbor Road in Stony Brook, which was washed away in the Aug. 18-19 storm. "If you don’t ... make sure that everything is clear and working properly, then you’re going to run into these kind of issues. I’m not saying that’s the sole purpose of the collapse here, but it really contributes to it."

Herbst's construction trade group issued a report four years ago warning of the vulnerability of Long Island’s aging roadway drainage systems. The study laid out some of the broad impacts of flooding on Long Island, including property damage, delayed response time for emergencies, accelerated deterioration of infrastructure, damage to ecosystems and natural resources, and travel delays for commuters and goods.

The study raised several concerns about the adequacy of local roadway infrastructure, including 70-year-old catch basins that surpassed their life expectancy two decades ago, drainage conveyance systems in Nassau County designed "to handle rainfall events with a maximum intensity of 2½ inches per hour" — about 1½ inches less than what fell in some Long Island communities during last month’s storm — and some leaching basins along the Northern State Parkway that "have not been located or inspected in decades."

"Since most drainage features are underground and essentially ‘invisible,’ there is an ‘out-of-sight-out-of-mind’ philosophy which pervades [government] agencies," said the study, which urged increased investment in the inspection and modernization of drainage systems.

Spokespersons for the state Department of Transportation and for Nassau County Executive Bruce Blakeman did not respond to questions about what efforts are made to ensure road drainage systems are functioning properly ahead of storms, and about what plans, if any, they have to improve drainage systems to address changing climate standards.

Suffolk County officials said their road drainage efforts begin in the spring with the sweeping of county roads. Ahead of storms, county workers clean drains in low-lying and problematic areas with vacuum trucks, and install additional drains and pipes as necessary. During storms, county highway and engineering crews conduct "puddle surveys" of flood-prone areas that need to be addressed, according to county spokesperson Michael Martino.

Suffolk County Executive Edward P. Romaine, in a statement, said addressing the county's water and wastewater infrastructure is a "main focus" of his administration. He said the August storm "proves again that things have changed and extreme storms are becoming the norm." 

 Impacts on LIRR

In addition to impacting those traveling on Long Island by car, extreme precipitation events can also impact those traveling by rail. A Nissequogue River dam that broke in Blydenburgh County Park in Smithtown during the August storm caused severe flooding that extended into the Long Island Rail Road’s tracks, and forced a lengthy suspension of service on the Port Jefferson branch through the evening rush hour.

The LIRR’s low-lying Long Beach line has proved particularly vulnerable in recent years, leading the MTA to spend $120 million over the last decade to elevate and fortify much of its infrastructure along the branch. The Metropolitan Transportation Authority has signaled that protecting its system against weather will be a top priority in its next five-year Capital Program, which will be released later this month.

"We need to make huge investments to make our system more resilient to climate change," MTA chairman and CEO Janno Lieber said at a meeting with reporters at the LIRR's Jamaica headquarters Thursday.

Lieber noted that street flooding issues also impact Long Island commuters when they arrive in New York City. "Every time we have a torrential rainstorm and you see subway systems getting flooded, a lot of that has to do with the fact that the way things are designed above grade are not configured for the level of water we’re getting," he said.

Localized rainfall events

Some particularly catastrophic storms, like 2012’s Superstorm Sandy, an August 2014 storm that dumped more than a foot of water in three hours in Islip, and 2021’s Hurricane Ida, did help bring attention to the need to make local roadways more resilient. But Bernhardt said it’s the more frequent and localized rainfall events that public officials would get "more bang for the buck" protecting against.

"Last year it was Valley Stream. This year it’s Stony Brook. Next year, it’s probably somewhere else. But not all at once. And maybe it delays the necessary reaction, because for most of the area, it wasn’t all that extreme," Bernhardt said. "If we could put in the money now to have more robust infrastructure, it’ll pay off soon enough."

Kevin Reed, associate provost for climate and sustainability programming at Stony Brook University, said New York State has made strides in recent years to address climate change, including through the 2019 passage of the Climate Leadership & Community Protection Act, which he said helps "communities that are impacted the most become more resilient and adapt to a changing climate."

But he agreed that more must be done to make Long Island roads better able to withstand extreme weather. He called for exploring new technologies, like "green infrastructure that can handle the filtration of water," to help improve drainage in Long Island’s "most problematic areas" — including communities in eastern Suffolk that have little or no stormwater management apparatus. He also said that public planners should better use climate information and projections when designing and building new roadway projects.

More immediately, Reed said, public officials need to do a better job with upkeep of the "hodgepodge" methods of clearing Long Island’s roads of excess rain, including drains, retention ponds and rain gardens that, once built, often go neglected.

"We can always build better infrastructure, but I think one of the most overlooked parts is how you maintain that infrastructure," Reed said. "You can't just build a rain garden and leave it for 10 years. You actually have to maintain it."

By Alfonso A. Castillo

alfonso.castillo@newsday.com@alfonsoreports

Alfonso Castillo has been reporting for Newsday since 1999 and covering the transportation beat since 2008. He grew up in the Bronx and Queens and now lives in Valley Stream with his wife and two sons.