Study details coastal perils

Rising sea level could bring catastrophic damage to area

GALVESTON — In just 80 years, with sea levels expected to be nearly 2.5 feet higher than today, a storm similar to Hurricane Ike would cause catastrophic damage with a head-on hit to Galveston Bay, bringing an extra 10 feet of water or more into the area at landfall, according to new research.

The number of people displaced by the storm would be 65 percent higher than today, and five times more buildings would be damaged, scientists concluded.

The study, conducted by Texas A&M University-Corpus Christi’s Harte Research Institute for Gulf of Mexico Studies,

was presented Thursday at the National Association of Counties’ Gulf States Counties and Parishes Caucus Meeting in Galveston.

“Based on this study, the storm surge reaches further inland with the increase in sea level rise and it also increases the vulnerability of coastal communities,” said Mukesh Subedee, a scientist at the institute’s Coastal and Marine Lab and one of the investigators on the study.

Subedee presented the findings Thursday at the meeting, which drew county and parish elected officials from Texas, Louisiana, Alabama, Florida and Mississippi — areas that still are recovering from Hurricanes Harvey and Irma in 2017.

The next step, Subedee said, is to model the entire Texas coast for the impacts of sea level rise.

“The Texas coast is flat and low-lying, and so it’s sensitive to sea level rise,” Subedee said. “The Texas coast is prone to hurricanes, so we wanted to investigate the socio-economic impacts of a storm surge increase.”

More than 60 percent of the Gulf Coast and most bay shorelines are retreating and 25 percent of Texas’ population is living in these areas, Subedee said.

The study assumes that the sea level will have risen 2.4 feet by the year 2100. Using that assumption, researchers looked at how a storm like Hurricane Ike — which bore down on Texas and the Gulf Coast in 2008 and caused billions of dollars in damage — would impact communities now and in 2100 in Brazoria, Chambers, Liberty, Harris and Galveston counties.

The study found that the 2100 sea level rise would result in up to 10 feet of water inundating the area 12 hours prior to the hurricane’s landfall, and that flooding would worsen after the storm comes ashore.

The study showed that about 650,000 people would be displaced in 2100, compared to just under 400,000 who would be displaced today by a comparable storm.

And about 80,000 buildings would likely be damaged in 2100 compared to fewer than 20,000 today, with about 540 schools at risk compared to the 320 at risk in the current scenario, according to the study.

The result would mean billions of dollars more in damage. The study found that presentday devastation would cost about $42.3 billion. In 2100, this devastation would increase costs to $69.7 billion, Subedee said. All numbers are based on 2010 U.S. Census Bureau data and dollar values.

Sea levels have been rising around the world for more than 100 years, and the Upper Texas Coast is “particularly vulnerable” because the land is sinking through subsidence, according to the institute’s web site.

“For this low-lying coastal zone, the costs, both economic and ecologic, could be substantial,” according to the site. “Climate change, including sea level rise, will result in increased frequency, duration, and depth of storm surge flooding.”

The Houston region will experience the highest rate of sea level rise in Texas — and among the highest in the world — because of subsidence, according to the website.

To help combat the problem, the state is trying to work with the National Oceanic and Atmosphere Administration to develop Living Shorelines along the coast, said David Green, the state General Land Office’s deputy director of coastal resources, who also attended Thursday’s meeting.

The shorelines are protected, stabilized coastal edges made of plants, sand, rock or other natural materials. They provide wildlife habitats, as well as “natural resilience,” according to NOAA.

The shorelines serve to purify water, buffer floods, reduce erosion, store carbon, and attract wildlife to habitat, according to NOAA.

But that might not be enough to stop a significant storm surge, Subedee said.

“During landfall, there were 110 mph winds from Ike and that was able to move water inland,” he said, “but in the future, when water surface elevation has increased, the water will move even further inland.”