Coastal development invites hurricane damage.

• Author: Baker, Earl J.

As more and more homes are being built along the shoreline, their vulnerability to nature's fury becomes a problem with which legislation must deal.

HURRICANE ANDREW struck south of Miami, Fla., on Aug. 24,1992, and caused $20-30,000,000,000 in property damage, making it the costliest natural disaster in the history of the U.S. Andrew was a strong, but compact, hurricane and could have caused much more destruction had its track been a few miles farther north. The damage and human misery caused by Andrew raised questions about the type of development society should allow in hurricane-prone regions.

In 1900, when Galveston, Tex., was devastated by a hurricane, the government response was to construct a massive seawall along the front of all of the city and much of the entire island. In 1983, Hurricane Alicia struck Galveston and caused hundreds of millions of dollars in damage. This time, the city issued a temporary moratorium on building permits for substantial repairs and reconstruction and hired additional inspectors to ensure that rebuilt structures would not be as susceptible to damage as they were before the storm. Erosion caused by the storm moved the coastal vegetation line farther inland, thereby moving the state-owned property line inland, and the state laid claim to the newly situated property, even though a number of private structures were located seaward of the new line. In nearby Baytown on Galveston Bay, almost all of the 300 homes in a housing subdivision that had a recurrent flooding problem caused by subsidence were purchased under a Federal program, and the land was given to the local government to be maintained as open space.

These policies reflect a shift over the years in attitudes toward the occupation of coastal areas. Today, there is less willingness to allow inherently vulnerable development to be placed in harm's way, reduced emphasis upon modifying hurricane-prone areas to make them more amenable to development, and more effort to require that growth in these areas be modified to mitigate the effects of the hazards indigenous to the ocean shore.

Wind is the component of hurricanes that affects the largest number of coastal residents because it extends farthest inland. Winds in Hurricane Hugo, for example, resulted in severe damage in Charlotte, N.C., almost 200 miles from the coast. The vast majority of the damage from Andrew was caused by wind in communities away from the open coast in south Florida. Housing and other buildings can be constructed affordably to withstand wind in most hurricanes, and about half the Gulf and Atlantic states either have statewide building codes addressing wind resistance in hurricanes or require communities to adopt one of three model codes developed by organizations that specialize in that activity. Although there is professional disagreement as to the adequacy of particular codes, the majority of engineers agree that most hurricane wind damage occurs due to lack of compliance with codes already in place. South Florida has one of the strongest and most enforceable building codes in the nation, but much of Andrew's damage occurred in homes that did not comply with it.

Mobile homes create a special problem. They experience major damage even in moderate hurricanes, and their windblown debris causes further destruction to other structures. After Andrew, at least one community in south Florida imposed a moratorium on new mobile homes until its policy on them could be reviewed. Many communities require that mobile home parks have a...