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Flooded Basement Help in Southold, NY
Connect with a local specialist now.
Water coming up through the basement floor or walls? Groundwater stays under most Southold basements, averaging about 15 ft down, but 1,171 addresses are mapped within 10 ft of it. Call and we'll connect you with a local specialist. Acting fast limits the damage.
- You call Tell us what you're seeing
- We connect you With a local specialist covering Southold
- They arrange A visit with you
- Water table ~15 ft on averagewithin 10 ft at 1,171 addresses
- Rain and roof runoff reach the wallsgutters, downspouts, grading
- Gets in at window wells and crackssurface water on most streets
Southold at a glanceWhat drives basement flooding here
Flood risk: High- water table depth
- 15ft
- of developed area in FEMA zone AE
- 16.4%
- of homes built before 1970
- 49%
Why basement flooding happens in Southold
The 15 ft average in Southold leaves most slabs clear of groundwater, and the first things to check are gutters, grading and window wells. Not at the 1,171 address points mapped within 10 ft of it.
At roughly 14 ft of elevation, there is not much fall available in Southold to move water away from a house by gravity alone.
Because Southold's soil is well drained, water that lands on the property normally leaves before it reaches the wall. A basement taking water on ground like this is worth investigating as a routing problem rather than a waterproofing one.
About 16.4% of the developed land in Southold is mapped inside the FEMA AE (100-yr floodplain) zone — worth separating from the groundwater question, because insurance treats them differently.
If the water has any smell to it, stop treating it as seepage. Southold is mostly unsewered, and a failed system against a 15 ft water table is a wastewater problem wearing a basement problem's clothes.
Seasonal housing accounts for about 30% of Southold. A humidity sensor or a monitored water alarm is worth more than a bigger pump in a house nobody is standing in.
For context on flood damage in the area: since 1978, ZIP 11971 has recorded 345 NFIP flood insurance claims, with $3,828,225 paid. That figure covers the whole ZIP code, not Southold alone (why we report it that way), and NFIP policies do not cover groundwater seepage or a failed sump pump.
More local measurements for Southold
- Soil drainage
- Well drained
- Ground elevation
- 14 ft
- Hurricane Sandy high-water mark
- 6.9 ft The highest of 2 marks USGS surveyed in Southold after the 2012 storm, in feet above the NAVD88 datum. Southold's ground elevation on this page uses the same datum, so the two can be compared directly.
- Home heating fuel
- 54% fuel oil Fuel oil heats 54% of occupied homes in Southold and utility gas 27%, by Census estimate (oil within 10 points). Where a basement holds an oil tank, floodwater can float or tip it and spill oil. New York's DEC says to remove the oil before pumping out the water, and never to pump it into the yard.
- Nearest fire department
- Southold Fire Department
Southold's land area
- FEMA coastal wave zone (VE)
- FEMA 100-year floodplain (AE, AO)
- The flood-zone figure above says how much of the land these zones cover.
Sources: FEMA NFHL / NOAA SLOSH, US Census ACS, USDA SSURGO, Suffolk County sewer districts — measured over developed land only. Verified 2026-10-18. How we measured this. Check them at source: FEMA flood map for Southold · Census profile for Southold · Permitted wastewater facilities in ZIP 11971
Streets wholly inside the flood zone
The flood map puts 420 of Southold's 4,640 address points inside a special flood hazard area: 313 in zone AE, 89 in zone VE and 18 in zone AO. On 5 streets every address is inside it:
- N Sea Dr — all 45 addresses
- Leeton Dr — all 34 addresses
- Carole Rd — all 9 addresses
- Old Cove Blvd — all 5 addresses
- Takaposa Rd — all 5 addresses
Streets with the most addresses in the zone · How streets are counted
How Southold compares nearby
On the measurements behind basement water, Southold tracks the 5 areas around it closely: 16.4% of developed land in a flood zone here, 10.5% on average across them.
| Area | Water table | In flood zone | Built pre-1970 |
|---|---|---|---|
| Southold | 15 ft | 16.4% | 49% |
| Cutchogue | 27 ft | 9.8% | 49% |
| Greenport | 11 ft | 9.6% | 73% |
| Greenport West | 18 ft | 10.4% | 41% |
| Peconic | 15 ft | 11.2% | 44% |
Neighbors are the nearest areas. How we measured this.
Basement Flooding help near Long Island Sound, Hashamomuck Pond and Corey Creek
Groundwater under Southold averages 15 ft deep and rises within reach of a basement floor on some streets, so a wet basement there may be coming from below. Southold has no public sewer to speak of: homes run on cesspools and septic tanks, and a full or failing one pushes sewage back into the house.
When you call, we connect you with a local water damage specialist who will extract standing water, establish how far it traveled into walls and insulation, and dry the structure to a measured moisture content.
This page covers Southold, ZIP 11971.
Signs you need basement flooding help now
- Water seeping through your floor drain or walls
- Visible standing water on the basement floor
- A strong musty or sewage smell
- Damp walls or white mineral deposits (efflorescence)
- Sump pump running constantly or failing
Who to call for a flooded basement in Southold
(631) 440-4144Tell us what you are seeing. We connect you with a local specialist covering Southold who handles basement flooding.
Frequently asked questions about basement flooding in Southold
Why do basements flood in Southold?
On most streets, not from groundwater: the water table under Southold averages about 15 ft down, below a basement floor. But the USGS depth-to-water map puts it within 10 ft of the surface at 1,173 of 4,640 address points, and there it can press on the slab. Elsewhere, water reaching a basement came from the surface: roof discharge against the wall, ground falling back toward the house, a window well or a hatchway.
Is Southold in a flood zone?
Southold's FEMA-mapped zone is AE (100-yr floodplain), covering about 16.4% of the developed area, per FEMA's flood map (NFHL). Note that the flood zone describes surface flooding — groundwater seepage into a basement can happen well outside it.
Are older homes in Southold more at risk?
49% of Southold's housing predates 1970 and the average home is about 55 years old. Foundations from that period generally predate exterior waterproofing membranes, so seepage tends to show up there first.