Griffin said the buildings in the square follow all flood planning regulations. “Sure, there’s some risk, but [those moving to the area] don’t seem to worry about it,” he added.

Public officials in Clear Lake have taken a varied approach to addressing the risk of a storm like Mighty Ike. Ryan Edghill, emergency management coordinator for League City, said he’s worked on emergency drills for storm surges as high as 26 feet above sea level.

Nassau Bay’s city manager, Reynolds, was more skeptical of the scenario. “Is that like a doomsday calculation?” he asked.

Galloway, Nassau Bay’s emergency manager, said the region works hard to educate people about hurricane risk. But many probably aren’t aware of a Mighty Ike scenario “because we’ve had such an influx of population from folks from out of state,” he said.

If a storm like that hits, it’s not clear if everyone could evacuate soon enough. People could end up stranded on the road as the surge hits, and as the region’s population has grown since Ike, the growth in road capacity hasn’t caught up.

“There are a lot of these neighborhoods [in Clear Lake] where there’s one way in, one way out,” said Eldridge, of the local emergency planning committee. “And they don’t have a way to get out if a flood comes and then people are trapped.”

* * *

The tendency of Clear Lake-area communities to flood, and the unique risk people there face of storm surge from nearby Galveston Bay, has been a topic of public interest and study for decades.

According to many local area mayors and economic development advocates, the best way to protect the region is to build something originally dubbed the “Ike Dike” and later the “coastal spine.”

That proposal involves building a floodgate between Galveston Bay and the Gulf of Mexico to stop storm surge from entering the bay.

But almost eight years after the concept was suggested, no finalized proposal for a coastal spine exists. The delays have frustrated Mitchell, of the Bay Area Houston Economic Partnership.

“I’ll predict it right now: It will be built two years after the next hurricane hits,” Mitchell said.

Despite the lack of progress, Mitchell — whose own office is in Nassau Bay Town Square — doesn’t think it makes sense to stop or curb development in Clear Lake now. Such storms are too rare to justify slowing growth, he said.

Brody doesn’t want to slow growth either. But building codes could be more strict, elevation requirements could be higher and other flood defenses such as drainage systems could be strengthened, he said.

“We’re continuing to put more people in harm’s way,” Brody said. “And it makes sense, until some kind of disaster happens.”​​​​​​

* * *

By most accounts, Houston exists as it does today because of a hurricane that hit nearby Galveston. And because of its location, Galveston will always bear the bigger brunt of a storm than its larger neighbor.

In the years leading up to 1900, Galveston was Texas’ powerhouse maritime metropolis. The 27-mile-long barrier island—situated between Houston and the Gulf of Mexico—boasted the state’s busiest seaport and had a population roughly equal to Houston’s at the time. With more millionaires per capita than any place in the United States, Galveston was alternately called the “Ellis Island of the West” and the “Wall Street of the South.”

Houston, whose shipping lane was a narrow, muddy bayou, struggled to compete with Galveston’s natural, deepwater, and easy-to-access port.

But that September, a powerful hurricane engulfed the low-lying island, killing an estimated 6,000 people inside Galveston city limits and as many as 6,000 more outside it. The “Great Storm of 1900” still is the deadliest natural disaster in U.S. history and prompted the rapid construction of a 17-foot seawall along part of the island—considered a modern feat of engineering at the time. (The initial 3.3-mile segment was completed less than four years after the storm hit.)

Using millions of pounds of landfill, crews also boosted the city’s elevation by more than a dozen feet in some places—the Gulf-facing side in particular. Those measures have helped Galveston better cope in subsequent storms, although the island remains enormously vulnerable. When a hurricane hits the region, Galveston is the first point of contact for the storm surge coming in from the Gulf. It also gets hit by that storm surge again, from the backside, when that wall of water recedes from the mainland.

In the years that followed the 1900 storm, Houston steadily stole Galveston’s greatness.

The power shift was set in motion in large part by the efforts of a retired Houston congressman, Tom Ball, who helped persuade his former colleagues to split the cost of dredging the city’s shallow shipping bayou to accommodate larger ships. The result was the Houston Ship Channel, a 52-mile maritime waterway that connects the Port of Houston to the Gulf. It was completed in 1914 during the iconic Texas oil boom.

The waterway sits behind Galveston, which offers some storm protection to ships, tankers, barges and the facilities they serve. Shipping experts describe the geography as a big advantage over other ports that sit directly on the coast.

With its own deepwater port, Houston quickly gobbled up Galveston’s shipping activity, and its population boomed. Today, the city has nearly 50 times more people than it did 100 years ago.

Meanwhile, Galveston’s population is scarcely larger than it was back then, with less than 50,000 full-time residents today.

In the century since the Great Storm, the island has been walloped by eight more hurricanes that have killed hundreds of people, forcing Galveston into an almost constant state of repairing and rebuilding. The last time was in 2008, when Hurricane Ike nearly destroyed the city all over again.

Outsiders—even insiders—often talk about it as a city that shouldn’t exist. Of the 10 barrier islands and peninsulas on the Texas coast, it is the only one with a sizable population of permanent residents.

More than 23 percent of Galveston’s residents live at or below the poverty line. That is notably higher than the state’s overall poverty rate of 17.6 percent, though not much worse than Houston’s (22.9 percent).

While Galveston has slipped from prominence, it has become the state’s go-to summer getaway spot, and tourism is key to its economy.

While Houston, which sits about 50 miles inland, will never be as physically vulnerable to hurricanes as Galveston, several scientists and public officials say Houston is more at risk because it has much more to lose.

In recent years, Houston has seen major growth in low-lying areas like Clear Lake. Those areas would be hit hard in a major storm, as would the city’s industrial complex.

As officials mull whether to build something like a super seawall or gate system to protect the Houston region from storm surge, many have pointed to Galveston’s demise as a reason to do so.

“We saw what happened to Galveston at the turn of the century,” said Janiece Longoria, the chairwoman of the Port of Houston Authority, on the fifth anniversary of Ike. “We can’t afford to gamble with the future in Houston.”

This article appears courtesy of ProPublica, and was co-produced with The Texas Tribune. Additional design and software development by Ryan Murphy of The Texas Tribune and Sisi Wei of ProPublica. Additional GIS work by Jeremy W. Goldsmith.

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Neena Satija is an investigative reporter and radio producer for The Texas Tribune and Reveal, a public radio program from the Center for Investigative Reporting. Connect Twitter

Kiah Collier is a reporter for The Texas Tribune.

Al Shaw is a news application developer for ProPublica.