NYC flood zones are one of two kinds of map New Yorkers are told to check, and mixing them up is common. The city puts the difference in one line: “flood zones use letters to determine risk and evacuation zones use numbers to help you know when to evacuate.” This guide explains both, what the letters mean, which flood map applies in New York City, and where to look up an address.
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Flood Restoration NYC is an independent referral service, not a restoration company, and it publishes no maps of its own. The official finders are named below.
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Flood zones: FEMA’s letters
Flood zones come from FEMA’s Flood Insurance Rate Maps, or FIRMs. FEMA calls the high-risk areas on them Special Flood Hazard Areas (SFHA): the area that will be flooded by the flood event having a 1-percent chance of happening in any year. That event, FEMA says, is “also referred to as the base flood or 100-year flood.”
| Label | What FEMA calls it |
|---|---|
| A, AO, AH, A1-A30, AE, A99, AR | Special Flood Hazard Area (high risk) |
| V, VE, V1-V30 | Special Flood Hazard Area (high risk) |
| B or X (shaded) | Moderate flood hazard: between the 100-year and the 500-year flood limits |
| C or X (unshaded) | Minimal flood hazard, outside the SFHA |
NYC Flood Maps translates the high-risk zone into terms a homeowner feels: it “has a one percent chance of flooding in any given year, and a twenty-six percent chance of flooding over the life of a thirty-year mortgage.” A “100-year flood”, in other words, does not mean once a century: over a 30-year mortgage the chance is about one in four.
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Evacuation zones: the city’s numbers
Evacuation zones are a separate map from NYC Emergency Management. “New York City’s hurricane contingency plans are based on six evacuation zones,” ranked by the risk of storm surge, with zone 1 the most likely to flood. The number is there, in the city’s words, to help you know when to evacuate. NYC Emergency Management is clear that hurricane evacuation zones “should not be confused with flood insurance risk zones,” which come from FEMA.
| Flood zone | Evacuation zone | |
|---|---|---|
| Written as | Letters (AE, VE, X…) | Numbers (1 to 6) |
| Made by | FEMA (Flood Insurance Rate Maps) | NYC Emergency Management |
| Used for | Flood risk, insurance and building rules | Knowing when to leave before a hurricane |
| Look it up | NYC Flood Maps | The Hurricane Evacuation Zone Finder, or 311 |
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Which flood map applies in NYC
This is where New York gets complicated. NYC Flood Maps says the city received its first FEMA FIRMs in 1983, and they were not significantly updated until FEMA released Preliminary FIRMs in December 2013. FEMA released Preliminary FIRMs in January 2015; the city filed a technical appeal in June 2015, finding that FEMA’s modeling overestimated Base Flood Elevations by 1 to 2.5 feet across the city. In October 2016 FEMA agreed with the city’s findings and said it would work with the city to revise the 2015 Preliminary FIRMs.
Meanwhile, the city says, the “New York City Building Code will continue to require new and substantially improved buildings to use the Preliminary FIRMs until a new map is created and adopted by the City.” So the map that matters can depend on what you are doing: building or substantially improving, or buying insurance. The city’s timeline page also notes that property owners in the updated 100-year floodplain with a mortgage from a federally backed lender will be required to buy flood insurance once maps are finalized. When that will be is not something this site can say; check NYC Flood Maps for the current status.
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How to check an address
- Go to NYC Flood Maps on nyc.gov for FEMA’s flood maps as they apply in the city.
- Look up the evacuation zone with NYC Emergency Management’s Hurricane Evacuation Zone Finder, or call 311.
- Write down both: the flood zone letter and the evacuation zone number.
- If you are buying, renting or renovating, ask an insurance agent what the flood zone means for a policy, and an architect or engineer what it means for the work.
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Outside the zones is not outside the risk
The flood zones do not tell the whole story. NYC Health stresses that rainfall flooding “can happen anywhere in the city,” and Hurricane Ida’s deaths in 2021 came mostly in basement apartments flooded by rain, not surge. A home in Zone X can still take water through the basement drain when the sewers overflow. The basement flooding and sewage cleanup guides cover that kind of flood.
For what flood insurance is and how the National Flood Insurance Program works in general, read flood insurance basics. For the steps after water has already come in, see flood cleanup in NYC.
Already flooded? Send the form with your borough and what happened, and an independent local flood restoration provider can contact you.
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Questions people ask
Am I in a flood zone in NYC?
Look up the address on NYC Flood Maps. A letter A or V zone is FEMA’s high-risk Special Flood Hazard Area; B or shaded X is moderate; C or unshaded X is minimal.
What is the difference between a flood zone and an evacuation zone?
Flood zones use letters and come from FEMA’s Flood Insurance Rate Maps; evacuation zones use numbers, 1 to 6, and come from NYC Emergency Management. They are different maps for different purposes.
What does a 100-year flood mean?
A flood with a 1-percent chance of happening in any year. NYC Flood Maps notes that this works out to a 26% chance over a 30-year mortgage.
Which FEMA flood map does NYC use?
For new and substantially improved buildings, the NYC Building Code requires the Preliminary FIRMs until a new map is adopted. Check NYC Flood Maps for the current status of the maps for insurance.
NowWater in the building?
Tell us where and what happened, and an independent local provider can contact you.