Overview

Georgia’s Sea Level Is Rising

And Initial Solutions Will Cost Over $1 Billion

The sea level off Georgia’s coast is up to 11 inches higher than it was in 1950.1 This increase is mostly due to Georgia’s sinking land, and it’s causing major issues. There is 100 miles of coastline and 14 barrier islands on Georgia’s coast at risk from sea level rise, which are both not only home to wildlife and many communities, but protect inland communities from flooding events.2 Sea level rise around Georgia could cause the loss of not only important wetlands, but historic structures and communities. There are already over 13,000 properties at risk from frequent tidal flooding in Georgia.3 The state is planning over $1 billion in sea level rise solutions, which include dredging projects, building seawalls, and drainage improvements.

Sea level rise is speeding up

The sea level around Fort Pulaski, Georgia, has only risen by 11 inches since 1950. Its speed of rise has accelerated over the last ten years and it’s now rising by over an inch every 2 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 Fort Pulaski tide gauge since 1950

Causes & Complications

Why Are Sea Levels Rising?

While there are four causes of sea level rise in Georgia, land sinkage is the main contributor.5 Because the land is getting lower each year, due to a process called subsidence, Georgia is particularly vulnerable to an increased rate of sea level rise in the future. Click here to learn more about these causes.

How Land Sinkage Increases Sea Level Rise

Most flooding happens during the fall

King tides are unusually high tides that are created during months when the sun, moon, and earth align. The combined gravitational pull of the moon and the sun creates much higher tides, called king tides. In some places, king tides are brought on by changes in the weather and ocean patterns. In places like Fort Pulaski, king tides are typically over a foot and a half higher than normal.1 Add that to the 11 inches of sea level rise since 1950, and you end up with flooding even on sunny days.

Solutions aren’t simple

In Georgia the sea level is rising more rapidly than some coastal areas because as the ocean water is rising, the land is sinking and shorelines are eroding. With a complex coastal ecosystem and over 14 barrier islands, solutions for Georgia’s sea level rise aren’t simple, but they are necessary and urgent.

Already, we are seeing work days missed due to the inability of certain communities to access flooded routes to work. We are seeing saltwater intrusion into our drinking water supply. And we are seeing homeowners inundated with floodwaters on sunny days.

Megan Desrosiers, Executive Director, One Hundred Miles
Megan Desrosiers

Forecast

What's the Future of Sea Level Rise?

In the last decade, the speed at which Georgia’s sea level is rising has increased and is now rising by as much as 1 inch every 2 years.1 Around Fort Pulaski, it took about 20 years for sea levels to rise by 6 inches.1 Scientists now forecast that in just the next 14 years, the sea level will have risen by another 6 inches.6

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 Georgia.7 Currently, the USACE high forecast, seen as the darkest red line, is the most likely projection.

Georgia SLR comparison English
Georgia SLR comparison English
Created with Highcharts 6.1.3Fort Pulaski Sea Level Rise Forecasts

Data show that as seas rise, more regular events will become more extreme. Our lives will change. We must recognize this fact and work now to mitigate the future impacts.

Megan Desrosiers, Executive Director, One Hundred Miles
Megan Desrosiers

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 around 4 and a half inches, tidal flooding has increased by 100% in some areas of Georgia since 2000.8

Flooding
How sea level rise effects Georgia

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 King 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 Matthew, 2016

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 2050.9

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 2016, Hurricane Matthew hit Georgia, causing widespread flooding and $10 billion in damages.10 Without sea level rise, Hurricane Matthew’s storm surge of nearly 8 feet would have been lower.11

Hurricane Matthew, 2016

Costs

What's at Risk in Georgia?

Georgia, especially because the state has 100 miles of coastline that is host to a massive ecosystem which makes up one-third of the salt marshes remaining on the Eastern Seaboard.2 The barrier islands on Georgia’s coast are not only home to wildlife and many communities, but protect inland communities from flooding events.2 In addition to the loss of important coastal wetlands and habitats, sea level rise around Georgia could cause the loss of historic structures and communities, devastation of infrastructure, and contamination of ground wa­ter by saltwater intrusion.12

Beaches
Beaches

Rising seas increase the speed of beach erosion, pulling more sand from the beach into sea. Replacing the sand is possible, but expensive.

Coastal Wetlands
Coastal Wetlands

Sea level rise can disrupt coastal wetlands, which puts important ecosystems in danger, threatens habitats, and leaves communities exposed to dangerous storm surge.

Homes & Cars
Homes & Cars

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

In Tybee Island there are 632 residential properties already at risk from repeated tidal flooding, by 2033 that number will increase to 980 as sea levels rise. In Skidaway Island, 379 properties at risk will turn into 587 within 15 years. In Savannah there are 688 properties at risk, which will become 970. And in Wilmington Island, there are 624 properties at risk, which will increase to 761 by 2033. Click here to explore other coastal areas in Georgia that are at risk at FloodiQ.com.

Georgia is spending over $1 billion

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

Savannah Harbor
Savannah Harbor

The USACE is midway through a $973 million dredging project to deepen the Savannah Harbor.13

St. Marys
St. Marys

St. Marys has a flood resiliency project with projected costs up to $160 million, $34 million of which has already been adopted.14

Tybee Island
Tybee Island

Tybee Island has adopted an adaptation plan, which includes drainage solutions and building a seawall, that could cost well over $50 million to implement.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.