Great Kills Flood Exposure · NYC DEP Separate Storm Sewer Area
Great Kills, Staten Island - MS4 Area
Properties here drain through separate storm sewers: rain runs in its own pipes straight to Great Kills Harbor, 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 Great Kills, Staten Island specifically.
4,118 properties in Great Kills, Staten Island drain through separate storm sewers to Great Kills Harbor. Flood Form rates 35% of them Moderate or High for stormwater, 14% for sewer backup, 7% for groundwater, and 17% for coastal flooding. 93% of lots have yard area that legally qualifies for on-site infiltration. Ground elevation varies widely here: the land drops from about 74 ft to 12 ft, sloping down toward the southeast. Rain that falls uphill runs down the streets toward the low end, so properties there take on water from the blocks above as well as their own, and are the first to see ponding and sewer backups when the pipes fill. Properties higher up shed water downhill and pond less, so where a lot sits on the slope matters more here than any average for the area. The median building dates to 1970. 3% of parcels sit over a historic stream or pond. Their runoff reaches the water through 8 NYC DEP storm sewer outfalls.
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Flood exposure in Great Kills (Great Kills Harbor)
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.
35%
Stormwater exposure: Moderate or High
14%
Sewer Backup exposure: Moderate or High
7%
Groundwater exposure: Moderate or High
17%
Coastal exposure: Moderate or High
What sets Great Kills (Great Kills Harbor) apart
The three figures on which this area differs most from the rest of NYC’s separate storm sewer areas.
93%
Legally eligible for on-site infiltration
Higher than 85% of NYC's separate storm sewer areas. More yards here have room to soak stormwater in.
62%
Average impervious cover per lot
Lower than 80% of NYC's separate storm sewer areas. More open ground to absorb rain.
7%
Properties with Moderate or High groundwater exposure
Lower than 80% of NYC's separate storm sewer areas. Few lots show signs of a shallow water table.
Stats computed from Flood Form’s NYC parcel data as of October 28, 2026
Where Great Kills’s storm sewers drain
The waters NYC DEP maps this area’s storm sewer outfalls to, by number of properties.
2,536
Great Kills Harbor
1,111
Great Kills Creek Harbor
443
Great Kills
28
Great Kills Creek/Harbor
Common solutions for Great Kills 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
Modular Drywell System
An NDS Flo-Well modular drywell system lets water soak into the ground on-site.
Complexity: Moderate · 1–3 weeks
Rain Garden
A shallow planted depression that collects runoff from roofs and paved areas and lets it soak into the ground over a day or two.
Complexity: Low · 1–3 weeks
Area Drain
A yard area drain — a surface inlet at the lowest point in the yard — provides a direct outlet for stormwater that pools on the site.
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
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 Great Kills (Great Kills Harbor)
What does it mean that Great Kills has separate storm sewers?
This part of Great Kills, Staten Island 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 Great Kills Harbor, 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 Great Kills (Great Kills Harbor)?
The most widespread exposure in Great Kills is stormwater: Flood Form rates 35% of properties Moderate or High for it. The share is 14% for sewer backup, 7% for groundwater and 17% for coastal flooding. These figures describe the whole area, and exposure varies lot by lot within it.
Can properties in Great Kills (Great Kills Harbor) manage stormwater on site?
93% of lots in Great Kills 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 Great Kills matter for Great Kills Harbor?
Storm sewers here discharge runoff without treatment, so what washes off streets, roofs and yards ends up in Great Kills Harbor. 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 Great Kills (Great Kills Harbor)?
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
- Fresh Kills & Richmond CreekEltingville & New Springville20,698 properties · 28% with Moderate or High stormwater exposure
- Raritan BayTottenville & Huguenot14,780 properties · 32% with Moderate or High stormwater exposure
- Lower New York BaySouth Beach & New Dorp17,690 properties · 43% with Moderate or High stormwater exposure
- Lemon CreekPrince's Bay & Annadale7,858 properties · 19% with Moderate or High stormwater exposure
- Arthur KillRossville & Charleston4,448 properties · 23% 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