Area guideSmithtown
Water Damage Restoration Help in Smithtown, NY
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The hamlet of Smithtown · Town of Smithtown
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 Smithtown, 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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Only 5 of the 8,518 addresses in Smithtown are in FEMA's flood zone, so the water that damages homes here usually comes from their own pipes and drains, not from a flood.
This page is about the hamlet of Smithtown — population 27,531. If you meant the Town of Smithtown, which also covers Commack, Hauppauge, Kings Park, Nesconset and 6 more, start from the list of every area we cover. The measurements on this page are for the hamlet of Smithtown, not the whole town.
Smithtown at a glanceTap a figure to see it on the map
Flood zone AEFlood zone. 5 of the 8,518 addresses here are inside FEMA's mapped flood zone. 24 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 750 ft across. Color shows how many of its addresses are mapped inside the zone:
- Fewer than half
- Half or more
Groundwater. At 887 of the 8,518 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. At the other 7,631, water in a basement usually comes in from above.
Each square is about 750 ft across. Color shows the typical depth under its addresses (USGS map, spring 2013):
- Within 10 ft317
- 10 to 14 ft570
- 14 to 25 ft1,220
- Deeper than 25 ft6,411
Sewer. 125 of the 8,518 addresses in Smithtown have a county sewer main mapped past them. That does not mean every house is connected.
At the other 8,393, a backup means a cesspool or septic tank, and a pumping company. On a main, it means a plumber, or the sewer district if the main is blocked.
Each square is about 750 ft across. Color shows how many of its addresses have a mapped main:
- Fewer than half
- Half or more
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 Smithtown homes
Smithtown sits almost entirely outside FEMA's flood zone (less than 1% of its built-up land is in it). What damages homes here is closer to home: a full or failing cesspool, a wet basement, pipes bursting in the cold and an aging pipe giving way.
- Sewage coming up a drain. Keep children and pets away from sewage, and stop running water in the house until the line is clear, because every flush adds to what comes up. Of the 8,518 addresses in Smithtown, 8,393 have no sewer main mapped past them and rely on a cesspool or septic tank; when a system backs up, the first sign is often sewage in a floor drain, a basement toilet or a shower. Cesspool Overflow help in Smithtown
- Water in the basement. Homeowners policies usually exclude groundwater seeping in, so photograph the damage and read your policy before the cleanup starts. The 49 ft average hides a spread: on some Smithtown streets groundwater comes close enough to a basement floor to seep in after a wet spell. Basement Flooding help in Smithtown
- 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. About 52% of Smithtown's homes heat with fuel oil, and a tank that runs dry in a cold snap takes the heat with it; pipes in outside walls and crawlspaces freeze first. Frozen Pipe Burst help in Smithtown
- 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. About 60% of Smithtown's homes were built before 1970, and pipes from that era, galvanized steel and cast iron, corrode from the inside until a joint or a section gives way. 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 Smithtown
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.
412 streets, from county address records. Nothing you type is sent anywhere.
Streets with a mapped sewer main
County records map an active sewer main past 125 of 8,518 address points in Smithtown. On 4 streets nearly every address has one; the largest:
- Gazebo Ln — 43 addresses
- Smithtown Cres — 25 addresses
- Graystone Ln — 12 addresses
- Cindy St — 11 addresses
Quick facts — Smithtown
Flood and storm
- FEMA flood zone
- AE (100-yr floodplain)A small area, with 5 addresses mapped inside it.
- Hurricane Sandy high-water mark
- 8.6 ft The one mark USGS surveyed in Smithtown after the 2012 storm, in feet above the NAVD88 datum — a reading at one point, not a level across all of Smithtown. Ground elevation here averages 85 ft on the same datum.
- Water nearby
-
Long Island Sound to the south-east, Stump Pond to the south and New Millpond to the south.
Each direction is to its nearest point, from the center of Smithtown.
All 10 named water features
- North-east: Nissequogue River
- South-east: Long Island Sound, Phillips Millpond, Northeast Branch
- South: Stump Pond, New Millpond, Blydenburgh Park Pond
- South-west: Willow Pond, Webster Pond, Vail Pond
Smithtown's land area
- FEMA 100-year floodplain (AE)
- The flood-zone figure above says how much of the land these zones cover.
Homes here
- Sewer status
- Unsewered (Cesspool/Septic)
- Home heating fuel
- 52% fuel oil Utility gas heats 38% of occupied homes in Smithtown. Census estimates; the oil figure is within 6 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 38% of Smithtown'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
- Smithtown Fire Department
- Nearest emergency shelter
- Hauppauge High 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
- 11787
Sources: FEMA NFHL / NOAA SLOSH, US Census ACS, USDA SSURGO, Suffolk County records. Verified 2026-10-18. How we measured this.
Smithtown and nearby areas
3 of the other 5 areas compared here have a larger mapped floodplain share than Smithtown.
- Nissequogue 11.0%
- Kings Park 1.7%
- Head of the Harbor 1.1%
- Smithtown 0.8%
- Nesconset 0.0%
- Saint James 0.0%
- San Remo —
Share of developed area inside FEMA's mapped floodplain, largest first. No figure is shown for San Remo: it has no boundary of its own to measure.
Smithtown has the shallowest average groundwater of the 6 areas compared here.
- Smithtown 49 ft
- Nesconset 50 ft
- Saint James 82 ft
- Kings Park 85 ft
- Nissequogue 88 ft
- Head of the Harbor 111 ft
- San Remo —
Average depth to groundwater, shallowest first. No figure is shown for San Remo: it has no boundary of its own to measure.
Smithtown has the lowest average ground of the 6 areas compared here.
- Smithtown 85 ft
- Nissequogue 94 ft
- Nesconset 109 ft
- Kings Park 121 ft
- Head of the Harbor 131 ft
- Saint James 132 ft
- San Remo —
Average height above sea level, lowest first. No figure is shown for San Remo: it has no boundary of its own to measure.
Smithtown's water table is 49 ft, against an 85 ft average across the 6 areas around it. Groundwater sits shallower under Smithtown than under the areas around it. The second gap is ground elevation: 85 ft against 118 ft next door. Smithtown sits on lower ground than the areas around it.
Compared with the areas around Smithtown. How we measured them.
Frequently asked questions about Smithtown
Is Smithtown in a flood zone?
Smithtown's FEMA-mapped flood zone is AE (100-yr floodplain), covering about 0.8% of the developed area, per FEMA's flood map (NFHL).
Does Smithtown have public sewer, or cesspools?
Smithtown is unsewered — nearly every property runs on its own cesspool or septic system.
How deep is the water table in Smithtown?
The measured water table runs about 49 ft below the surface on average across Smithtown. It is mapped within 10 ft at 317 of 8,518 addresses and within 25 ft at 2,107.
How old are homes in Smithtown?
The average home in Smithtown is about 59 years old, and 60% of the housing stock predates 1970 — older plumbing and unwaterproofed foundations are a common factor in local water damage.
About the figures for Smithtown
Check them at the source
Who to call for water damage in Smithtown
(631) 440-4144Tell us what is happening. We connect you with a local specialist who covers Smithtown.