New study says more than 27,000 LI businesses could suffer economic loss from flooding

A new first of its kind study shows that more than 27,000 businesses in Nassau and Suffolk counties could risk economic losses due to flooding, with risk levels ranging from moderate to high to extreme.

The Islandwide study mined data from Federal Emergency Management Agency flood zones, "anecdotal zones" along the South Shore and New York State's "downstate coastal risk areas" that helped determine flooding risk on the North Shore. It developed detailed maps showing the flood risk jurisdictions where many businesses are located, said Richard Annitto, vice president of GIS at LiRo-Hill. The group conducted the study in collaboration with the Long Island Regional Planning Council, which financed it.

During a presentation of the "Islandwide Economic Flood Risk Study" at a council meeting this week on Zoom, Annitto told council members it was "believed to be the first study of its kind because a lot of these flood studies focus on residential properties." But this study, he said, "interfaced data from a company called Data Axle, and we focused on blue economy businesses to try to determine the value, and also what potentially could be at risk." Blue economy businesses operate in or are related in some way to the ocean or coastal areas. 

According to the study, there were 1,824 businesses Islandwide considered in "extreme risk" of economic loss due to flooding, or 6.7%; 5,114 at high risk, or 18.8%; and 20,300 at moderate risk, or 74.5%, for a total of 27,238 businesses, whose total annual sales volume was $42.6 billion. Those businesses had more than 206,000 employees, the study said. 

"This turned out to be a very successful database," Annitto said, adding it could be used for development planning and for economic studies. It focused on 177 jurisdictions that had business data in risk areas. The flood risk study can be found on the council's website at lirpc.org.

Annitto said community profiles also were available on the maps, "So someone can go to their town ... their city or their village and determine, 'OK, what's at risk?'"

The planning council's chairman John Cameron, said in a statement: "As we have seen several times in just the last 18 months alone, the devastation from severe flooding brought about by heavy rainfall presents the potential for severe economic loss along our coastal communities. This important study provides a tool for all levels of government and the private sector to develop strategies to minimize the risk."

When broken out by county, Nassau had 17,395 businesses at risk of flood damage across the three risk categories of moderate (72%), high (21.7%) and extreme (6.3%). The total annual sales volume of those businesses for Nassau was $27.5 billion. The study said those businesses had a total of 131,522 employees.

For Suffolk, the total number of businesses facing flood risk was 9,843, with an annual sales volume of $15.2 billion and 74,800 employees, with 79.1% of businesses at moderate risk of loss; 13.5% with high risk and 7.4% with extreme risk of economic loss, according to the study.

While Suffolk is the largest county geographically and has a higher population, Annitto cited Nassau's density as a factor in the higher total of businesses facing flooding risk. "What you see Islandwide is, about 6.7% of the businesses are in an extremist zone. ... What's interesting is, of 1,824, [a] substantial number are in Nassau County (1,094), which actually makes some sense because of the density of Nassau County, the density of businesses and number of employees," he said.

The study also looked at the impact of severe rainfall in its risk assessment, citing the powerful thunderstorm overnight on Aug. 18-19, 2024, that flooded parts of the North Shore in Suffolk, wiped out Harbor Road in Stony Brook, for example, and damaged homes and businesses at an estimated cost of $41 million.

By Olivia Winslow

olivia.winslow@newsday.com@newsollie