Area guideRiverhead
Water Damage Restoration Help in Riverhead, NY
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The hamlet of Riverhead · Town of Riverhead
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 Riverhead, 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 $9.7 million on 510 claims in ZIP 11901, which takes in Riverhead, so water has reached homes here before.
This page is about the hamlet of Riverhead — population 14,993. If you meant the Town of Riverhead, which also covers Manorville, Wading River, Calverton, Aquebogue and 5 more, start from the list of every area we cover. The measurements on this page are for the hamlet of Riverhead, not the whole town.
Riverhead at a glanceTap a figure to see it on the map
Flood risk: MediumFlood zone. 39 of the 5,443 addresses here are inside FEMA's mapped flood zone. 126 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 800 ft across. Color shows how many of its addresses are mapped inside the zone:
- Fewer than half
- All
Groundwater. At 1,729 of the 5,443 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 3,714, water in a basement usually comes in from above.
Each square is about 800 ft across. Color shows the typical depth under its addresses (USGS map, spring 2013):
- Within 10 ft976
- 10 to 14 ft753
- 14 to 25 ft2,084
- Deeper than 25 ft1,630
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 Riverhead homes
Riverhead's sewers cover the downtown area; properties outside it are on cesspools. Riverhead has two kinds of water risk: flooding from outside, and inside the house, a cesspool backing up, water getting into the basement and a failed hose or supply line.
- Water coming in from outside. A new flood policy usually takes 30 days to begin, so one bought after a storm is forecast will not cover that storm. A small part of Riverhead, about 2.3% of its built-up land, is in FEMA's flood zone; on those streets a home has at least a 1-in-100 chance of flooding in any year. Since 1978, ZIP 11901 has logged 510 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. Sewage in the house is contaminated water, so it needs a crew that cleans, disinfects and dries, not a mop and a fan. Riverhead is a mix of sewered streets and streets on cesspools, so the first question about a backup is which one the house has: a blocked line to the street, or a full system in the yard. Cesspool Overflow help in Riverhead
- Water in the basement. Homeowners policies usually exclude groundwater seeping in, so photograph the damage and read your policy before the cleanup starts. Riverhead's water table averages 30 ft, but on some streets it sits close enough to wet a basement floor, so whether seepage is a risk depends on the street. Basement Flooding help in Riverhead
- A leak or a burst pipe. If a pipe bursts, shut the main water valve first; a split supply line keeps running at full pressure until someone does. At about 42 years old on average, Riverhead's homes are younger than most in the county, so their plumbing is mostly modern and a sudden leak is worth tracing to a fixture or an appliance hose first. 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 Riverhead
See how many of its addresses are mapped inside the FEMA flood zone and how deep groundwater is mapped under it.
208 streets, from county address records. Nothing you type is sent anywhere.
Streets inside the FEMA flood zone
39 of 5,443 address points in Riverhead are mapped inside a FEMA special flood hazard area. These streets hold the most of them:
- E Main St — 9 of 205 addresses
- Mcdermott Ave — 8 of 9 addresses
- Peconic Ave — 7 of 9 addresses
- Riverview Dr — 5 of 19 addresses
- River Ave — 5 of 23 addresses
Quick facts — Riverhead
Flood and storm
- FEMA flood zone
- AE (100-yr floodplain)
- Hurricane Sandy high-water mark
- 8.1 ft The one mark USGS surveyed in Riverhead after the 2012 storm, in feet above the NAVD88 datum — a reading at one point, not a level across all of Riverhead. Ground elevation here averages 37 ft on the same datum.
- Water nearby
-
Long Island Sound to the north, Flanders Bay to the south-east and Merritts Pond to the south.
Each direction is to its nearest point, from the center of Riverhead.
All 6 named water features
- North: Long Island Sound
- South-east: Flanders Bay, Sawmill Creek, Terrys Creek
- South: Merritts Pond, Peconic River
Riverhead's land area
- FEMA coastal wave zone (VE)
- FEMA 100-year floodplain (A, AE, AO)
- The flood-zone figure above says how much of the land these zones cover.
Homes here
- Sewer status
- Partially Sewered
- Home heating fuel
- 34% fuel oil Utility gas heats 48% of occupied homes in Riverhead. Census estimates; the oil figure is within 8 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
- 2000s 28% of Riverhead's homes were built in the 2000s, more than in any other decade band. Census estimate, within 7 points. Homes from the 2000s are about 20 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
- Riverhead Fire Department
- Nearest emergency shelter
- Riverhead 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
- 11901
Sources: FEMA NFHL / NOAA SLOSH, US Census ACS, USDA SSURGO, Suffolk County records. Verified 2026-10-18. How we measured this.
Riverhead and nearby areas
4 of the other 6 areas compared here have a larger mapped floodplain share than Riverhead.
- Flanders 11.9%
- Aquebogue 10.0%
- Riverside 7.6%
- Northville 2.4%
- Riverhead 2.3%
- Calverton 0.8%
- Baiting Hollow 0.7%
Share of developed area inside FEMA's mapped floodplain, largest first.
4 of the other 6 areas compared here have shallower average groundwater than Riverhead.
- Riverside 9 ft
- Aquebogue 15 ft
- Calverton 25 ft
- Flanders 27 ft
- Riverhead 30 ft
- Northville 51 ft
- Baiting Hollow 93 ft
Average depth to groundwater, shallowest first.
3 of the other 6 areas compared here have lower average ground than Riverhead.
- Riverside 16 ft
- Aquebogue 21 ft
- Flanders 31 ft
- Riverhead 37 ft
- Calverton 53 ft
- Northville 59 ft
- Baiting Hollow 101 ft
Average height above sea level, lowest first.
Across the 6 areas around Riverhead the sewer coverage averages 3%. Here it is 37%. Riverhead is more sewered than the areas around it. Seasonal-housing share separates it as well — 0%, against an 11% neighborhood average. Fewer homes in Riverhead sit empty for part of the year than in the areas around it.
Compared with the areas around Riverhead. How we measured them.
Frequently asked questions about Riverhead
Is Riverhead in a flood zone?
Riverhead's FEMA-mapped flood zone is AE (100-yr floodplain), covering about 2.3% of the developed area, per FEMA's flood map (NFHL).
Does Riverhead have public sewer, or cesspools?
Riverhead is partially sewered: roughly 37% of developed land is inside an active sewer district, so whether you're on a cesspool depends on your street.
How deep is the water table in Riverhead?
The measured water table runs about 30 ft below the surface on average across Riverhead. It is mapped within 10 ft at 976 of 5,443 addresses and within 25 ft at 3,813.
How old are homes in Riverhead?
The average home in Riverhead is about 42 years old, and 38% of the housing stock predates 1970 — older plumbing and unwaterproofed foundations are a common factor in local water damage.
About the figures for Riverhead
Check them at the source
Who to call for water damage in Riverhead
(631) 440-4144Tell us what is happening. We connect you with a local specialist who covers Riverhead.