Overview

New York’s Sea Level Has Risen 9” Since 1950

And It's Costing Over $4 Billion

The sea level off New York’s coast is up to 9 inches higher than it was in 1950.1 This increase is mostly due to the slowing of the Gulf Stream and New York’s sinking land, and it’s causing major issues. In places like New York City, solutions can be complex because of the city’s unique location, vast network of underground railroads, and proximity to other large coastal cities. With nearly half of the state’s residents living in marine counties, sea level rise puts New York’s people, resources, and economy at risk.2 There are already over 30,000 properties at risk from frequent tidal flooding in New York.3 The state is planning over $4 billion in sea level rise solutions, which include raising roads, fixing drainage, and building seawalls.

Sea level rise is speeding up

The sea level around Battery, New York, has risen by nearly 9 inches since 1950. Its speed of rise has accelerated over the last ten years and it’s now rising by 1 inch every 7-8 years.1 Scientists know this because the sea level is measured every 6 minutes using equipment like satellites, floating buoys off the coast, and tidal gauges to accurately measure the local sea level as it accelerates and changes.4

Created with Highcharts 6.1.3Sea Level Change in Inches19501960197019801990200020102016024681012

SEA LEVEL MEASUREMENT FROM BATTERY AREA TIDE GAUGE SINCE 1950

Causes & Complications

Why Are Sea Levels Rising?

While there are four causes of sea level rise in New York, the slowing of the gulf stream5 and land sinkage6 are the largest contributors. Because the Gulf Stream has slowed down, it leaves more water on the East Coast. This, combined with sinking land, makes New York particularly vulnerable to an increased rate of sea level rise in the future. Click here to learn more about these causes.

Gulf Stream
How Slowing of the Gulf Stream Increases Sea Level Rise
How Land Sinkage Increases Sea Level Rise

Most flooding happens in the winter

The highest tides in New York occur during nor’easters. These wintertime storms push more water to the coast, raising high tides even higher, especially when combined with an increased gravitational pull from the moon. In places like Battery, these tides are typically over a foot and a half higher than normal high tides.1 Add that to the 9 inches of sea level rise since 1950 and you end up with flooding even on sunny days.

Solutions aren’t simple

In New York the sea level is rising more rapidly than some coastal areas because as the ocean water is rising, the land is sinking. In places like New York City, solutions can be complex because of the city’s unique location, vast network of underground railroads, and nearby cities such as Jersey City and Hoboken, which can be affected by mitigation projects in New York.7

Forecast

What's the Future of Sea Level Rise?

In the last decade, the speed at which New York’s sea level is rising has increased and is now rising by as much as 1 inch every 7-8 years.1 Around Battery Park, it took the sea level 48 years to rise by 6 inches.1 Scientists forecast that in just the next 14 years, the sea level will have risen by another 6 inches.8

Scientists are not certain how fast the ocean will warm and ice will melt. They expect water levels to continue to rise faster, but are not sure just how fast. Therefore scientists from the National Oceanic and Atmospheric Administration (NOAA) and the US Army Corps of Engineers (USACE) have made predictions based on ranges from low to high.

Below you can see the range of the NOAA and USACE high and intermediate forecasts for various locations around New York.9 Currently, the USACE high forecast, seen as the darkest red line, is the most likely projection.

SLR speeding up - New York English
SLR speeding up - New York English
Montauk
Created with Highcharts 6.1.3Montauk Sea Level Rise Forecasts

Flooding

Why Are Floods More Frequent?

When the ocean rises high enough, high tides cause flooding even on sunny days. Even though the sea level has only risen by nearly 2 inches, tidal flooding has increased by 247% in some areas of New York since 2000.10

Flooding
How sea level rise affects New York

Flooding even when there’s no rain

Drainage systems are designed to channel excess rainwater from the streets and drain it into the sea. But with the pressure from rising sea levels and higher tides, seawater can get pushed into these pipes and spill out into the streets. This causes flooding even on days without rain.

Drain A
Drainage Under Normal Tidal Conditions
Drainage With High Tide / Sea Level Rise

Increased storm surge flooding

Unfortunately, slightly higher sea levels make hurricanes even more damaging. Just a few more inches of sea level rise allow a hurricane to push more water onto the land, even if the hurricane itself doesn’t make landfall.

Hurricane Sandy, 2012

Higher sea levels create a higher launching point for storm surge. These small changes in sea level rise are enough to turn what were 100-year storm surges into much more frequent events. In fact, in a third of 55 coastal sites studied throughout the US, 100-year storm surges will be 10-year or more frequent events by 2050.11

This means that in many coastal cities, if you bought a house with a 30-year mortgage today, by the time you paid off your mortgage you could be experiencing extreme 100-year storm surges ten times more frequently due to sea level rise alone. This does not include the added risk of more intense storms resulting from warmer water and a warmer atmosphere, which could further increase storm surge damage.

In 2012, Hurricane Sandy made landfall and caused $50 billion in damages to the state.12 Without sea level rise, Hurricane Sandy’s 9.5 foot storm surge would have been lower.13

Hurricane Sandy, 2012

Costs

What's at Risk in New York?

Sea level rise and flooding pose a significant risk to New York’s people, resources, and economy. The state’s marine counties are home to nearly half of the state’s residents2 and New York City alone houses 1 million workers at over 200,000 small businesses.14 With stronger storm surge brought on by high sea levels, all of New York City’s infrastructure faces serious risk, as major flooding has the ability to not only shut down parts of the city, but cause billions of dollars worth of damage.

Homes & Cars
Homes & Cars

Storm surges or flooding can damage the underside of your car or the first level of your home.

Businesses
Businesses

Flooding can shut down businesses and impact sales. It can fill first-level floors of shops, damaging the interior and merchandise.

Public Transportation
Public Transportation

Flooding can inundate underground tunnels and low lying roads for days, leaving train and bus routes impossible to operate.

In New York City there are 5,592 residential properties already at risk from repeated tidal flooding, by 2033 that number will increase to 8,194 as sea levels rise. In Freeport, 2,294 properties at risk will turn into 2,666 within 15 years. In Oceanside, there are 1,160 properties at risk, which will become 1,917. And in Long Beach, there are 498 properties at risk, which will increase to 1,159 by 2033. Click here to explore other coastal areas in New York that are at risk at FloodiQ.com.

New York is spending over $4 billion

Some cities have sufficient resources to deal with this problem while others do not. New York will need solutions at the individual, local, state, and federal levels to protect its coastal communities.

New York City
New York City

New York City has a $3.7 billion plan to deal with sea level rise and flooding.15

Nassau County
Nassau County

Towns in Nassau County have planned for $360 million in projects from seawalls to raised roads to drainage.16

Suffolk County
Suffolk County

Suffolk County is spending $388 million to upgrade their sewer system to withstand flooding and storms.15

What can you do?

Individuals, mayors, legislators, governors, and Congress can work together to build protections before flooding, to build back stronger after flooding, and to create plans that future-proof our communities. Click here to see what solutions can help protect your home or what your community can do.