Photo: Everett Collection

Hurricane season has been quiet this year—it’s deep into September, and we’re only on Hurricane Fred—but that’s small consolation to those on the eastern end of Long Island who have found that their homes now officially lie in a floodplain. It’s a designation that comes with mandatory insurance policies that can end up costing thousands of dollars a year.

Since 2003, FEMA has been modernizing its records, a handful of counties at a time, using GPS-like technology to update flood maps that in many cases were hand-drawn 50 years ago. The remapped floodplains of Nassau County went into effect September 11, and Suffolk’s will be implemented this Friday. (New York City’s new maps went into effect two years ago.) In Nassau, some 25,000 houses have found themselves remapped into an official floodplain. In Suffolk, more homes have been dropped from the rolls of the flood-prone than have been added, but in pockets—most notably the village of Sagaponack—the maps have been redrawn to add more residents.

Homeowners in any flood zone are required by their mortgage lenders to buy flood insurance; it’s underwritten by FEMA, and sold through insurance brokers. Those who want to insure their homes past the $250,000 FEMA cap can buy additional insurance on the excess market, where coverage can run into the tens of thousands of dollars annually, according to Toni Quaresima, a broker at the Morley Agency in Southampton.

Some homeowners have hired independent surveyors to contest their flood-zone status. Senator Chuck Schumer has gotten involved upstate, asking FEMA to remap parts of Sullivan and Monroe counties. But that’s a shortsighted view, says Walter Bundy, the storm-water manager for Southampton. He suggests that the maps are too conservative, and that FEMA faces political pressure to understate the risk. “The true flood risk is depicted not on the flood maps but on the hurricane-inundation maps, which FEMA also puts out,” he says. “The flood maps only represent 1 percent of the real, true flood-prone areas.” In other words, the real scandal here might not be the homeowner complaints and conspiracy theories (one New Jersey woman told the Times that she was convinced the new maps were an agency conspiracy to raise money in the wake of Hurricane Katrina) or standards inconsistencies (Thomas Downs, a meteorologist with the consultancy firm Weather 2000, says, “They are being extra-careful, and in certain areas people are getting screwed”), but the fact that the new maps might not be any more helpful than the ones they replaced.

The current Suffolk County map is based on data resulting from the so-called Great Hurricane of 1938. But just because a building has never flooded in the past doesn’t mean that it can’t flood in the future. “Floodplains are dynamic things,” admits Doug Bellomo, the director of FEMA’s risk-analysis division. “They change with time.”

Most surprising, while the new flood maps take into account rising population density and erosion, they ignore climate-change projections almost entirely. “It’s very sobering to look at the sea-level rise,” Bundy says. “Nobody can agree on the rate, but we’re being told that it could be up to a foot within ten years. Which is a lot: One foot can equate to maybe two feet of flooding. Right now, everyone’s sticking their heads in the sand.”

That hasn’t stopped people from building near the coastline. (Apollo Management president Joshua Harris’s new mansion is rising on a $45 million Gin Lane lot partially within the new flood zone.) But Quaresima, for one, says she would think twice about it. “The house would have to be really elevated,” she says. “But then you’re putting yourself out there for wind damage. Really, you have to have a lot of money. That’s the only way to live on the water.”

Have good intel? Send tips to