How To Build Hurricane-Proof Cities

In the age of climate change, the only way to protect the American coastal metropolis is to rethink it entirely.

John Bazemore / AP

Almost exactly 117 years ago, a Category 4 hurricane made landfall on the barrier-island city of Galveston, Texas, with the storm surge and winds destroying at least half of the residential areas and killing at least 6,000 people. The September 8, 1900 catastrophe was one of the most destructive and costly natural disasters in American history, and even generations later it’s the watch word of sorts for what nature is capable of, and how seriously humans need to take it.

One of the reasons Galveston—which suffered damage from Hurricane Harvey in late August—is still around today is because the surviving residents rebuilt around the memory of destruction. Authorities at the federal, state, and local levels joined in building a massive 10-mile-long seawall to guard the city from the brunt of storm-driven waves. Galveston residents also changed the governing structure of the municipality in order to begin work on a most ambitious engineering effort: a project to raise the entire city above flood level, which required lifting buildings by as much as 16 feet and filling in foundations with millions of tons of sand.

Turn-of-the-century Galveston might seem a poor example for some of the challenges modern cities face from hurricanes. Miami, Florida, which endured a powerful—but not direct—blow from Hurricane Irma on Sunday, is the center of a metropolitan area of 5.5 million people, several orders of magnitude larger than Galveston’s 37,000 in 1900. Ditto for Greater Houston, which is the fourth-largest metropolitan area in the country, and which dwarfs the land area of even present-day Galveston, which has also grown larger and harder to protect than its previous iteration. Other coastal metropolises with the highest risks from tropical weather, flooding, and sea-level rise are also large, sprawling and increasingly complicated. The task of guarding them and of creating plans to deal with powerful storms in the future is almost too big to fathom.

But fathom it those cities must, if they want to survive yearly hurricane seasons that appear to be worsening. In Miami, dramatic action might be necessary the soonest. The city, which some experts predict could be mostly underwater as sea levels rise in the next century, is perhaps the most ill-equipped to deal with a direct hit from a hurricane, although surprisingly considering its location, it rarely has to.

At least in one domain, Miami and other Floridian cities are much better positioned to withstand hurricanes than they used to be. When Hurricane Andrew destroyed whole neighborhoods in cities across the state in 1992, one key factor in its destructiveness was the flimsiness of Florida homes. Then, a shoddy set of building codes in different municipalities led to thousands of homes whose builders made the kinds of decisions—roofing staples instead of nails, particle board instead of wood, and leaving mobile homes completely unmoored—that might not even have passed muster inland, let alone in a peninsula intersecting the Gulf of Mexico and the Caribbean.

But since then, Florida’s buildings have gotten their act together. In 2002, legislators passed a statewide building code that requires buildings to at least be able to withstand winds of up to 111 mph, and requires homes in “high velocity hurricane zones,” like Miami-Dade, to meet requirements of up to 130 mph. Evidence shows that those new building codes have helped, as insurance claims have dropped both in number and dollar amount since their implementation. Outside of Florida, the implementation of hurricane-resistant building codes has been pursued to minimize the destruction of hurricane-force winds, from the Outer Banks of North Carolina to the United States Virgin Islands.

The integrity of homes and buildings are only one part of the equation, just as wind is only part of the equation with hurricanes. As construction in the United States has evolved to withstand more extreme winds, the threats from storm surge and floods have increased. And saving the city might mean thinking similarly to Galveston way back when. As outlined in a 2013 article in Rolling Stone, the 20-year-plan to keep the city from sinking includes overhauling city drainage systems, adding more stormwater pumps, and elevating new roads and homes. Greater feats of engineering, like building a seawall and maybe even lifting the entire city, are also in the realm of possibility.

But Miami’s example, where the city’s plan to deal with hurricanes requires taking the Galveston model and scaling up to ever-more-complicated and grandiose construction projects, might not be sustainable, and ultimately doesn’t address one of the reasons why flooding is so bad: the design of cities themselves.  “The approach is to engineer the problem away,” says Philip Berke, a professor of land use and environmental planning at Texas A&M University. “So what's exposed in the floodplains from hurricanes and floods is just dramatically increasing from one year and one decade to the next.”

In the aftermath of Harvey, Houston has faced severe criticism for a lack of zoning, planning, and for a pattern of development that only emphasized flood hazards. It’s become a common refrain that Houston’s low-density sprawl, the extreme rate of concrete and asphalt-pouring in the suburbs, and the degradation of wetlands by developers create the conditions that led to multiple 100-year floods even before Harvey, and the need for dramatic projects to save the city. Those projects are inspired by the same mega-engineering logic that moved Galveston residents: Plans to make massive expansions to the Galveston seawall with the creation of an “Ike Dike” and floodgates, proposals for new levee systems, and even movements to raise the elevation of houses have come about as solutions.

But those solutions have also been criticized as short-sighted fixes that won’t be able to keep pace with increased flooding attributable to development. “Here in Texas, the market-driven economy, private property rights, and short-term financial gain are the approach, at the expense of thinking in the longer term and of the broader social costs,” Berke says.

Houston’s new forward-looking identity as “the city with no limits” in essence conflicts with its old identity as “The Bayou City.” The metropolitan area sits in the heart of a web of waterways and wetlands that serve as natural storm reservoirs for water during heavy rainfall, and are one of the few sources of drainage in the region, since its hard clay soils don’t allow rain to penetrate. As a consequence of its elevation and its very proximity to the ocean and those wetlands, Houston has always had frequent floods, but as it has grown, it has grown out instead of up, chewing up more and more of the wetland and replacing it with roads and parking lots that are impervious to water. As a result, the floodwaters often just sit there with nowhere  to go, and get progressively higher and more destructive over the years.

While Houston has received special scrutiny over the course of Harvey and its ensuing floods, the city appears to be something akin to the rule as opposed to an exception, especially in the areas most vulnerable to both hurricanes and sea-level rise. Southern metropolises tend to sprawl and replace miles of land with impervious sources, and wetlands are regularly drained and developed in watersheds across the country. Miami is a relatively compact city, but other major coastal metropolitan areas in Florida, including Jacksonville and Tampa, are monuments to sprawl, wetland degradation, and to future risk of hurricane damage. And through Monday morning, Jacksonville faced record floods from Irma.

For land-use planners, the only feasible long-term way to make coastal cities resilient is to rethink them. According to Danielle Spurlock, a frequent co-author of Berke’s and a professor at the University of North Carolina at Chapel Hill, city planners and other officials have so far been able to ignore any kind of meaningful reckoning with nature. “Although the magnitude of hurricane damage is huge, it's intermittent enough to where people have been able to avoid proactive money-spending to fix it, until now,” Spurlock says. “More frequent events are putting that kind of prioritization into question.”

One solution of course is to simply stop draining wetlands. But cities will also have to find out ways to reverse the existing degradation of wetlands, and to scale back roads and suburbs that are already built. Perhaps the latter goal is not feasible, but cities can use better planning to create more purposeful density inside their built boundaries and slow geographic growth, while at the same time restoring wetlands and even encouraging their growth and incorporation within existing areas.

At any rate, American cities will have to be built in a way that goes against what appears to be their nature, using the fullness of human ingenuity not to trample the earth and replace natural with the artificial, but to engineer both nature and the city in a way that emphasizes their codependence. Planners will have to look ahead to climate threats generations in the future, a prospect that seems bleak in the most vulnerable cities in the South, where leaders have either mostly ignored long-term considerations of climate change, as has Texas Governor Greg Abbott, or who, like Florida Governor Rick Scott, have actively suppressed discussion of the concept.

Still, Galveston provides an example of how disasters move policy, perhaps more quickly than anything else. Already, such a dynamic is playing out in Louisiana, where after Katrina state and federal authorities have embarked on a mission of reshaping the environment with “green infrastructure” aided by walls, pumps, and levees. Perhaps Harvey and Irma will also be landmark events that promote intellectual and financial investment in more resilient cities.