Coney Island & Gravesend Flood Exposure · NYC DEP Separate Storm Sewer Area
Coney Island & Gravesend, Brooklyn - MS4 Area
Properties here drain through separate storm sewers: rain runs in its own pipes straight to Coney Island Creek and Gravesend Bay, apart from the sewage. When a storm drops rain faster than the catch basins can take it in, the water collects on streets and low lots instead. Here’s what that looks like for Coney Island & Gravesend, Brooklyn specifically.
7,412 properties in Coney Island & Gravesend, Brooklyn drain through separate storm sewers to Coney Island Creek and Gravesend Bay. Flood Form rates 62% of them Moderate or High for stormwater, 29% for sewer backup, 84% for groundwater, and 87% for coastal flooding. 82% of lots have yard area that legally qualifies for on-site infiltration. The ground is fairly level here, typically about 9 ft. The median building dates to 1950. 6% of parcels sit over a historic stream or pond. Their runoff reaches the water through 17 NYC DEP storm sewer outfalls.
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Flood exposure in Coney Island & Gravesend (Coney Island Creek & Gravesend Bay)
The share of properties Flood Form rates Moderate or High for each type of flooding, on the same Minimal to High scale as an individual report.
62%
Stormwater exposure: Moderate or High
29%
Sewer Backup exposure: Moderate or High
84%
Groundwater exposure: Moderate or High
87%
Coastal exposure: Moderate or High
What sets Coney Island & Gravesend (Coney Island Creek & Gravesend Bay) apart
The three figures on which this area differs most from the rest of NYC’s separate storm sewer areas.
62%
Properties with Moderate or High stormwater exposure
The highest of NYC's separate storm sewer areas. Heavy rain ponds on or flows across more lots here.
85%
Average impervious cover per lot
Higher than 90% of NYC's separate storm sewer areas. More paved and built-over ground, so more rain becomes runoff.
87%
Properties with Moderate or High coastal exposure
Higher than 90% of NYC's separate storm sewer areas. More lots here are within reach of tides and storm surge.
Stats computed from Flood Form’s NYC parcel data as of October 28, 2026
Where Coney Island & Gravesend’s storm sewers drain
The waters NYC DEP maps this area’s storm sewer outfalls to, by number of properties.
4,497
Coney Island Creek
2,595
Gravesend Bay
180
Lower New York Bay, Gravesend Bay
140
Lower New York Bay
Common solutions for Coney Island & Gravesend properties
The measures that most often suit conditions here. An individual Flood Form picks the exact set for one lot. See all flood prevention solutions.
Downspout Diversion
Redirect roof downspouts away from the sewer system toward permeable yard areas, planters, or a rain barrel.
Complexity: Low · 1–4 weeks
Raised Threshold
Raising a doorway threshold with a concrete step or raised sill keeps shallow surface water from entering at ground-level and below-grade doors.
Complexity: Low · 1–2 weeks
Window Well
A lined enclosure around a below-grade basement window holds back soil and keeps surface water off the glass.
Complexity: Low · 1–2 weeks
Foundation Waterproofing
Exterior membrane waterproofing, interior footing drains, or crystalline waterproofing compounds address hydrostatic pressure against the foundation, depending on construction type.
Complexity: High · 3–6 months
Sump Pump
A sump pump with battery backup actively removes water that accumulates in below-grade spaces during groundwater rise or sewer surcharge events.
Complexity: Low · 1–4 weeks
Modular Drywell System
An NDS Flo-Well modular drywell system lets water soak into the ground on-site.
Complexity: Moderate · 1–3 weeks
Which of these fit your lot?
Your Flood Form rates your property’s exposure and recommends the measures suited to it.
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Questions about flooding in Coney Island & Gravesend (Coney Island Creek & Gravesend Bay)
What does it mean that Coney Island & Gravesend has separate storm sewers?
This part of Coney Island & Gravesend, Brooklyn is served by a separate storm sewer system, which NYC DEP calls an MS4. Catch basins and roof drains carry rain in their own pipes straight to Coney Island Creek and Gravesend Bay, while wastewater flows in another pipe to a treatment plant. Because rain doesn't share a pipe with sewage here, a storm is less likely to push sewage back into basements than in combined-sewer neighborhoods, though a blocked or undersized house sewer line can still back up. Flooding here mostly comes from runoff the storm drains can't take in fast enough, and from groundwater and tides.
How exposed to flooding is Coney Island & Gravesend (Coney Island Creek & Gravesend Bay)?
The most widespread exposure in Coney Island & Gravesend is coastal flooding: Flood Form rates 87% of properties Moderate or High for it. The share is 62% for stormwater, 29% for sewer backup and 84% for groundwater. These figures describe the whole area, and exposure varies lot by lot within it.
Can properties in Coney Island & Gravesend (Coney Island Creek & Gravesend Bay) manage stormwater on site?
82% of lots in Coney Island & Gravesend have yard area that legally qualifies for on-site infiltration, such as a drywell or rain garden. A lot without that room can still hold runoff with a detention tank or a blue roof.
Why does runoff from Coney Island & Gravesend matter for Coney Island Creek and Gravesend Bay?
Storm sewers here discharge runoff without treatment, so what washes off streets, roofs and yards ends up in Coney Island Creek and Gravesend Bay. Holding roof runoff on site with a rain garden, drywell, or detention tank cuts flooding on the property and what reaches the water.
How do I check one property in Coney Island & Gravesend (Coney Island Creek & Gravesend Bay)?
Enter the address on this page to get its free Flood Form. The report rates that property for stormwater, sewer backup, groundwater, and coastal flooding, and recommends measures suited to the lot.
Nearby separate storm sewer areas
- Sheepshead Bay & Gerritsen CreekSheepshead Bay & Madison19,430 properties · 57% with Moderate or High stormwater exposure
- Mill BasinMarine Park & Mill Basin10,396 properties · 56% with Moderate or High stormwater exposure
- Paerdegat BasinCanarsie & Bergen Beach3,164 properties · 57% with Moderate or High stormwater exposure
- Lower New York BaySouth Beach & New Dorp17,690 properties · 43% with Moderate or High stormwater exposure
- Fresh Creek & Hendrix CreekEast Canarsie & Starrett City5,116 properties · 48% with Moderate or High stormwater exposure
- Kill Van Kull & Upper New York BayWesterleigh & West New Brighton17,898 properties · 30% with Moderate or High stormwater exposure