Overview

Texas' Sea Level Is Rising

And It's Costing Over $12 Billion

The sea level off the coast of Texas is up to 18 inches higher than it was in 1950.1 This increase is mostly due to the sinking land, due to the pumping of large volumes of groundwater from deep in the earth, and is causing major issues. Solutions to this are complicated and involve filling the voids that have been created underground. As the sea level rises, it makes existing coastal flooding more severe and it erodes beaches, eventually submerging both wetlands and dry land. Many types of birds and fish that the state is home to depend on tidal wetlands. There are already over 13,607 properties at risk from frequent tidal flooding in Texas.2 The state is planning over $12 billion in sea level rise solutions, which include storm surge protection, drainage and erosion control, and flood mitigation projects.

Sea level rise is speeding up

The sea level around Galveston, Texas, has risen by 18 inches since 1950. Its speed of rise has accelerated over the last ten years, and is now rising by nearly 1 inch every year.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.3

Created with Highcharts 6.1.3Sea Level Change in Inches19501960197019801990200020102016-1001020

SEA LEVEL MEASUREMENT FROM GALVESTON AREA TIDE GAUGE SINCE 1950

Causes & Complications

Why Are Sea Levels Rising?

While there are four causes of sea level rise in Texas, land sinkage is the main contributor.4 Because so much water is being pumped out of the ground, the ground is sinking to where the water used to be.5 This makes Texas 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 Galveston, king tides are typically over a foot higher than normal tides. Add that to the 18 inches of sea level rise since 1950, and you end up with flooding even on sunny days.1

Solutions aren’t simple

In Texas the sea level is rising more rapidly than some coastal areas because as the ocean water is rising, the land is sinking. The sinking land in Texas is due to the pumping of large volumes of groundwater from deep in the earth, which makes solutions to mitigate the sinkage complicated because the voids that have occurred underground must be filled.

Forecast

What's the Future of Sea Level Rise?

In the last decade, the speed at which Texas’s sea level is rising has increased and is now rising by as much as 1 inch every year.1 Around Port Isabel, it took about 20 years to rise by 6 inches.6 Scientists forecast that in just the next 14 years, the sea level will have risen by another 6 inches.7

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 Texas.8 Currently, the USACE high forecast, seen as the darkest red line, is the most likely projection.

SLR Speeding Up - Texas
SLR Speeding Up - Texas
Sabine Pass North
Created with Highcharts 6.1.3Sabine Pass North 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 10 inches, tidal flooding has increased by 490% in some areas of Texas since 2000.9

Flooding
How sea level rise affects Texas

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 Harvey, 2017

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 2050.10

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 2017, Hurricane Harvey made landfall near Rockport Texas, causing catastrophic flooding and $127.5 billion in damages.11 Without sea level rise, Hurricane Harvey’s 11 foot storm surge would have been lower.12

Hurricane Harvey, 2017

Costs

What's at Risk in Texas?

There’s a lot at risk from sea level rise and flooding in Texas. Rising sea level makes existing coastal flooding more severe and erodes beaches, and has the potential to completely submerge both wetlands and dry land. Many types of birds and fish that Texas is home to depend on tidal wetlands. Shore erosion can not only leave homes exposed to dangerous storm surge, but can prevent access to public beaches and parks.5

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 Bolivar Peninsula there are 3,540 residential properties already at risk from repeated tidal flooding, by 2033 that number will increase to 4,799 as sea levels rise. In Galveston, 1,445 properties at risk will turn into 3,712 within 15 years. In Surfside Beach there are 1,318 properties at risk, which will become 1,904. And in Port Arthur, there are 858 properties at risk, which will increase to 1,157 by 2033. Click here to explore other coastal areas in New Jersey that are at risk at FloodiQ.com.

Texas is spending over $12 billion

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

Gulf Coast
Gulf Coast

The Texas Gulf Coast has an $11.6 billion storm surge protection plan.13

Houston
Houston

Houston is midway through $64 million flood mitigation projects.14

Texas
Texas

Texas has a Coastal Resiliency Master Plan that includes $1.5 billion in strategies to mitigate beach erosion, protect wildlife, and fortify sea walls.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.