Area guideIslip
Water Damage Restoration Help in Islip, NY
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The hamlet of Islip · Town of Islip
Water in the basement, a burst pipe, or sewage backing up into the house? Call and we'll connect you with a local specialist who covers Islip, even if you don't know the cause yet.
Water doesn't stay where it lands. It soaks into drywall, insulation and flooring, and mold can start within 24 to 48 hours.
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Since 1978, federal flood insurance has paid $13.8 million on 364 claims in ZIP 11751, which takes in Islip, so water has reached homes here before.
This page is about the hamlet of Islip — population 18,686. If you meant the Town of Islip, which also covers Brentwood, Central Islip, Bay Shore, Holbrook and 19 more, start from the list of every area we cover. The measurements on this page are for the hamlet of Islip, not the whole town.
Islip at a glanceTap a figure to see it on the map
Flood risk: MediumFlood zone. 41 of the 5,764 addresses here are inside FEMA's mapped flood zone. 239 more are within about 100 ft of its edge.
If your home is in it, most mortgage lenders must require flood insurance. That is a separate policy from homeowner's insurance, which usually covers a burst pipe or leaking appliance.
The percentage above counts all developed land, including lawns, parks and roads, not just homes.
Each square is about 600 ft across. Color shows how many of its addresses are mapped inside the zone:
- Fewer than half
- Half or more
- All
Groundwater. At 5,405 of the 5,762 addresses measured here, groundwater is within 14 ft of the surface, close enough to reach a basement floor.
In those basements, water can seep up through the floor and come back after pumping until the ground drains. The 357 measured deeper are the exception.
2 addresses fall where the groundwater map has no reading.
Each square is about 600 ft across. Color shows the typical depth under its addresses (USGS map, spring 2013):
- Within 10 ft4,803
- 10 to 14 ft602
- 14 to 25 ft357
Sewer. 5,159 of the 5,764 addresses in Islip have a county sewer main mapped past them. That does not mean every house is connected.
Where a house is connected, a backup is a blocked line. A plumber clears the pipe to the street. The sewer district clears the main.
Each square is about 600 ft across. Color shows how many of its addresses have a mapped main:
- Fewer than half
- Half or more
- All
What is happening at your home?
Other water emergencies we cover
Not sure which one fits? Call (631) 440-4144 and tell us what you see.
Why water gets into Islip homes
Islip has two kinds of water risk: flooding from outside, and inside the house, a sewer line backing up, groundwater coming up into the basement, pipes bursting in the cold and old plumbing leaking inside the walls.
- Water coming in from outside. If the water came in from outside, it is a flood claim: photograph the water line and every damaged item before cleanup starts, because the adjuster will ask for them. FEMA's flood zone covers about 4.4% of Islip's built-up land, and homes on those streets with a federally backed mortgage must carry flood insurance. Since 1978, ZIP 11751 has logged 364 federal flood insurance claims, so flood water has reached buildings in this ZIP before. Look up your street. Storm Damage Restoration help
- Sewage coming up a drain. Anything porous the sewage reaches, such as carpet or drywall, usually has to come out, and what stays has to be disinfected before it is dried. With Islip on public sewer, roots and grease in the line to the street are a common cause of a backup, and the first place it shows is a basement floor drain or a low toilet. Sewage Backup help in Islip
- Water in the basement. Groundwater in a basement returns after a pump-out unless a sump pump keeps up, so drying the walls and floor matters as much as removing the water. Islip's groundwater sits only about 9 ft down, within reach of a basement floor, which is why water can come up from below even when it is not raining. Basement Flooding help in Islip
- A burst pipe. A frozen pipe that has not split yet can be saved: open the tap and warm the line gently from the tap end back, never with a flame. Fuel oil heats about 38% of Islip's homes, so a missed delivery in a cold week can leave a house without heat long enough for a pipe to freeze and split. Frozen Pipe Burst help in Islip
- A leak in a wall or ceiling. A leak caught early is a drying job; one that has run for weeks inside a wall is a mold job, so have it opened up and dried properly. More than half of Islip's houses predate 1970, so many still have original supply and drain lines, where a slow leak can run behind a wall for weeks before it shows. Ceiling & Roof Leak Water Damage help
Insurance and safety guidance from FEMA FloodSmart, the CDC and the Red Cross. How we measured the figures.
Street by street in Islip
See how many of its addresses are mapped inside the FEMA flood zone, how deep groundwater is mapped under it, and whether a sewer main is mapped past it.
227 streets, from county address records. Nothing you type is sent anywhere.
Streets inside the FEMA flood zone
41 of 5,764 address points in Islip are mapped inside a FEMA special flood hazard area. These streets hold the most of them:
- Athasca Rd — 8 of 10 addresses
- Surf Ave — 7 of 8 addresses
- Smith Ave — 5 of 109 addresses
Streets with a mapped sewer main
County records map an active sewer main past 5,159 of 5,764 address points in Islip. On 192 streets nearly every address has one; the largest:
- Islip Ave — 145 addresses
- Main St — 122 addresses
- Moffitt Blvd — 113 addresses
- Nikia Dr — 111 addresses
- Ferndale Blvd — 109 addresses
- Smith Ave — 109 addresses
- Saxon Ave — 104 addresses
- Wilson Blvd — 101 addresses
Quick facts — Islip
Flood and storm
- FEMA flood zone
- AE (100-yr floodplain)
- Water nearby
-
Great South Bay to the south, Middle Bayberry Canal to the south and Pardees Ponds to the west.
Each direction is to its nearest point, from the center of Islip.
All 12 named water features
- North-east: Champlin Creek
- East: Knapps Lake, Upper Winganhauppauge Lake
- South-east: Lower Winganhauppauge Lake
- South: Great South Bay, Middle Bayberry Canal, West Bayberry Canal, East Bayberry Canal
- South-west: Orowoc Lake, Athasca Lake
- West: Pardees Ponds, Orowoc Creek
Islip's land area
- FEMA coastal wave zone (VE)
- FEMA 100-year floodplain (AE)
- The flood-zone figure above says how much of the land these zones cover.
Homes here
- Sewer status
- Sewered
- Home heating fuel
- 38% fuel oil Utility gas heats 50% of occupied homes in Islip. Census estimates; the oil figure is within 7 points. An oil tank can float or tip in a flood and spill. That is a separate cleanup from the water (NYS DEC). In a cold snap, an empty tank means no heat.
- When homes were built
- 1960s 30% of Islip's homes were built in the 1960s, more than in any other decade band. Census estimate, within 5 points. Homes from the 1960s are about 60 years old. Past 30 years, an insurance-industry study (IBHS) found supply and drain pipe problems three times as likely.
In an emergency
- Nearest fire department
- Islip Fire Department
- Nearest emergency shelter
- East Islip Middle SchoolNot every shelter opens for every storm, and the nearest may stay closed. Suffolk County announces which ones open; follow its alerts and local news before you go.
- ZIP code
- 11751
Sources: FEMA NFHL / NOAA SLOSH, US Census ACS, USDA SSURGO, Suffolk County records. Verified 2026-10-18. How we measured this.
Islip and nearby areas
1 of the other 6 areas compared here has a larger mapped floodplain share than Islip.
- Bay Shore 7.6%
- Islip 4.4%
- East Islip 4.0%
- North Great River 0.2%
- Central Islip 0.2%
- Islip Terrace 0.0%
- North Bay Shore 0.0%
Share of developed area inside FEMA's mapped floodplain, largest first.
None of the other 6 areas compared here has shallower average groundwater than Islip.
- East Islip 9 ft
- Islip 9 ft
- Islip Terrace 10 ft
- Bay Shore 12 ft
- North Great River 19 ft
- North Bay Shore 25 ft
- Central Islip 28 ft
Average depth to groundwater, shallowest first.
1 of the other 6 areas compared here has lower average ground than Islip.
- East Islip 17 ft
- Islip 25 ft
- Islip Terrace 30 ft
- Bay Shore 31 ft
- North Great River 40 ft
- North Bay Shore 62 ft
- Central Islip 64 ft
Average height above sea level, lowest first.
Across the 6 areas around Islip the sewer coverage averages 47%. Here it is 91%. Islip is more sewered than the areas around it.
Compared with the areas around Islip. How we measured them.
Frequently asked questions about Islip
Is Islip in a flood zone?
Islip's FEMA-mapped flood zone is AE (100-yr floodplain), covering about 4.4% of the developed area, per FEMA's flood map (NFHL).
Does Islip have public sewer, or cesspools?
Islip is on public sewer — about 91% of developed land sits inside an active sewer district, so backups here usually trace to the municipal main or your lateral.
Where is the nearest emergency shelter to Islip?
The closest Suffolk County emergency shelter to Islip is East Islip Middle School. Shelter openings vary by storm — confirm with Suffolk County OEM before traveling to one.
How deep is the water table in Islip?
The measured water table runs about 9 ft below the surface on average across Islip. It is mapped within 10 ft at 4,803 of 5,764 addresses and within 25 ft at 5,762.
About the figures for Islip
Check them at the source
Who to call for water damage in Islip
(631) 440-4144Tell us what is happening. We connect you with a local specialist who covers Islip.