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NYC Flood Map  ·  Brooklyn

Brooklyn Flood Map

Stormwater is the most widespread flood exposure in Brooklyn: 44% of its 275,697 lots rate Moderate or High. Next is sewer backup, at 21%. Below, what drives each kind of flooding here, from city and federal sources and Flood Form's parcel data.

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Bay Ridge (OH-017): 36% Moderate or High for stormwaterBay Ridge (OH-018): 35% Moderate or High for stormwaterBay Ridge (OH-019): 44% Moderate or High for stormwaterBedford-Stuyvesant (NCB-014): 40% Moderate or High for stormwaterBedford-Stuyvesant (RH-005): 44% Moderate or High for stormwaterBensonhurst (OH-015): 37% Moderate or High for stormwaterBorough Park (OH-002): 35% Moderate or High for stormwaterBrooklyn Heights (RH-011): 29% Moderate or High for stormwaterBrooklyn Heights (RH-012): 34% Moderate or High for stormwaterBrooklyn Heights (RH-014): 21% Moderate or High for stormwaterBrownsville (26W-003): 42% Moderate or High for stormwaterBushwick (NCB-015): 39% Moderate or High for stormwaterCarroll Gardens (RH-030): 46% Moderate or High for stormwaterCarroll Gardens (RH-031): 39% Moderate or High for stormwaterCarroll Gardens (RH-035): 25% Moderate or High for stormwaterCobble Hill (RH-016): 18% Moderate or High for stormwaterCobble Hill (RH-018): 33% Moderate or High for stormwaterCobble Hill (RH-019): 25% Moderate or High for stormwaterCypress Hills (26W-005): 51% Moderate or High for stormwaterEast Flatbush (CI-005): 53% Moderate or High for stormwaterEast Williamsburg (NCB-006): 45% Moderate or High for stormwaterEast Williamsburg (NCB-012): 49% Moderate or High for stormwaterFlatlands (CI-004): 47% Moderate or High for stormwaterFlatlands (CI-006): 43% Moderate or High for stormwaterGowanus (OH-005): 81% Moderate or High for stormwaterGravesend (OH-021): 44% Moderate or High for stormwaterGreenpoint (NCB-004): 16% Moderate or High for stormwaterGreenpoint (NCB-022): 39% Moderate or High for stormwaterGreenpoint (NCB-027): 59% Moderate or High for stormwaterNew Lots (26W-004): 46% Moderate or High for stormwaterPark Slope (OH-006): 27% Moderate or High for stormwaterPark Slope (OH-007): 24% Moderate or High for stormwaterProspect Heights (RH-034): 38% Moderate or High for stormwaterRed Hook (RH-028): 50% Moderate or High for stormwaterSouth Williamsburg (NCB-013): 29% Moderate or High for stormwaterSunset Park (OH-003): 22% Moderate or High for stormwaterSunset Park (OH-004): 22% Moderate or High for stormwaterWilliamsburg (NCB-007): 62% Moderate or High for stormwaterWilliamsburg (NCB-008): 56% Moderate or High for stormwater
Stormwater, Moderate or High0–15%15–30%30–45%45–60%60%+

Shaded areas are the combined-sewer sewersheds with their own page; select one to open it. Unshaded parts of Brooklyn still get a lot-by-lot rating in every Flood Form report.

Flood alerts and conditions in Brooklyn today

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Flood exposure across Brooklyn

The share of 275,697 lots Flood Form rates Moderate or High for each type of flooding, on the same Minimal to High scale as an individual report.

44%

Stormwater exposure: Moderate or High

21%

Sewer Backup exposure: Moderate or High

19%

Groundwater exposure: Moderate or High

12%

Coastal exposure: Moderate or High

2.7%

Lots in FEMA's 1% annual-chance floodplain

12.6%

Lots inside the 2012 Hurricane Sandy flood area

80.7%

Lots draining to a combined-sewer outfall

1.66%

Lots with a DEP-confirmed sewer backup on record

Computed from Flood Form’s NYC parcel data as of October 19, 2026

Why Brooklyn floods

Stormwater

In Flood Form's data, 44% of lots in Brooklyn rate Moderate or High for stormwater.

Brooklyn took about 27% of the city's Ida damage, concentrated in Canarsie and Flatlands, with clusters in Bushwick. In September 2023 the most intense rain, over 3 inches an hour, fell on central and northern Brooklyn.[1][2]

City sewers are built to drain roughly 1.75 inches of rain an hour, and some older ones less: before 1977 each borough set its own standard.[3]

Hurricane Ida brought 3.15 inches in a single hour to Central Park in 2021. More than half of the damage it caused fell outside both FEMA floodplains and the City's own stormwater flood scenarios.[3][1]

Flooding doesn't always follow the heaviest rain: in the September 2023 storm, parts of southern Queens and coastal Staten Island flooded badly with little intense rainfall, which the Comptroller tied to gaps in drainage.[2]

Sewer backup

In Flood Form's data, 21% of lots in Brooklyn rate Moderate or High for sewer backup, and 81% drain to a combined-sewer outfall.

DEP names Brooklyn, with the Bronx and Queens, among the boroughs where older combined sewers fall short of today's design standard.[4]

About 60% of the city's sewer system is combined, carrying both sewage and stormwater in one pipe. When intense rain exceeds pipe capacity, that mix can back up through basement drains and fixtures.[4]

DEP reports that rain-driven backups are now the most common kind, overtaking backups from grease and wipes, and that about 74,000 properties, most of them one- and two-family homes, are vulnerable in a storm of 1.75 inches per hour.[4]

Homes whose drains and fixtures sit below the nearby sewer, such as basements reached by a downward-sloping driveway, are the most likely to back up.[4]

Groundwater

In Flood Form's data, 19% of lots in Brooklyn rate Moderate or High for groundwater, and 8.8% sit near a buried historic stream or pond.

The City's plan lists eastern Brooklyn among the areas where groundwater flooding is a concern.[5]

The City's hazard mitigation plan names groundwater flooding a particular concern where neighborhoods were built while pumping held the water table down, and notes parts of Brooklyn and Queens where groundwater sits less than 10 feet below the surface. It adds that research on the problem is at an early stage.[5]

Coastal flooding

In Flood Form's data, 12% of lots in Brooklyn rate Moderate or High for coastal flooding. 2.7% fall in FEMA's 1% annual-chance floodplain, and 13% were inside the area Hurricane Sandy flooded in 2012.

The shoreline facing the Atlantic and Jamaica Bay is exposed to surge, with Coney Island, Sheepshead Bay and Gerritsen Beach singled out in the City's plan.[5]

Coastal flooding comes mainly from storm surge, while tidal flooding can happen on ordinary high tides without a storm.[5]

FEMA flood maps show coastal and river flooding, not the rainfall and sewer flooding behind most basement deaths in Ida.[6]

Neighborhoods in Brooklyn with the most stormwater exposure

Combined-sewer sewersheds in Brooklyn, ranked by the share of lots rated Moderate or High for stormwater.

All 39 Brooklyn sewersheds

Questions about flooding in Brooklyn

Is Brooklyn in a flood zone?

2.7% of lots in Brooklyn fall in FEMA's 1% annual-chance floodplain, the "flood zone" on federal maps, and 13% were inside the area Hurricane Sandy flooded. Federal maps cover coastal and river flooding, not rainfall: in Hurricane Ida, more than half of all damage fell outside FEMA floodplains and the City's stormwater scenarios. In Flood Form's data, 44% of lots here rate Moderate or High for stormwater.

Why does Brooklyn flood?

The most widespread exposure in Brooklyn is stormwater, with 44% of lots rated Moderate or High, followed by sewer backup at 21%. The remaining shares: groundwater 19%, coastal flooding 12%. Flash flooding happens when rain falls faster than the local sewers can drain it, and DEP reports that rain-driven backups are now the most common kind of sewer backup.

Which Brooklyn neighborhoods flood the most?

In Flood Form's data, the sewersheds in Brooklyn with the largest share of lots rated Moderate or High for stormwater are Gowanus (OH-005), Williamsburg (NCB-007) and Greenpoint (NCB-027). That ranking covers only the combined-sewer areas with their own page; every lot elsewhere is still rated in its own Flood Form report.

How can I check flooding at my Brooklyn address?

Enter your address for a free Flood Form. It rates the lot for stormwater, sewer backup, groundwater, and coastal flooding on a Minimal to High scale and recommends measures suited to it.

Sources

  1. [1] NYC Emergency Management, Record Rain in NYC: The Impacts of Post-Tropical Cyclone Ida (Damage Analysis Report) (2024).
  2. [2] NYC Comptroller, Is New York City Ready for Rain? An Investigation into the City's Flash Flood Preparedness (April 2024).
  3. [3] NYC Department of Environmental Protection, Increasing Stormwater Resilience in the Face of Climate Change: Our Long Term Vision (2022).
  4. [4] NYC Department of Environmental Protection, Protecting Your Home: Tools to Prevent Basement Sewer Backups and an Evaluation of Backwater Valves (December 2024).
  5. [5] NYC Emergency Management, NYC Hazard Mitigation Plan: Flooding Hazard Profile (current edition).
  6. [6] Scientific American, Deaths from Hurricane Ida Expose Flaws in FEMA Flood Maps (September 2021).

Bold sentences come from Flood Form’s parcel data and describe exposure across the borough, not the conditions at any one property. A Flood Form report rates an individual lot.

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