Coastal Crowding Places Millions in Hazard Areas

Population–and insurance–experts wish more Americans would heed the warning not to go near the water but clearly they aren’t listening. More than half of all Americans–153 million people–now live on or near a coast, an increase of 33 million since 1980. An additional 12 million are expected in the next decade.

While coastal counties include 53 percent of the population, they comprise just 17 percent of the nation’s land area.

This coastal population explosion poses a major evacuation worry in case of hurricanes or other natural disasters and also poses environmental and economic challenges to local governments, the National Oceanic and Atmospheric Administration noted in a recent report. Rising populations complicate evacuations and make emergency response more complex, according to the new publication, Population Trends Along the Coastal United States: 1980-2008, by the Special Projects Office of NOAA’s National Ocean Service. It considers a county coastal if it is on a coast or at least 15 percent of the county’s land area is in a coastal watershed. That includes 673 counties, some of them not directly on a coast.

Senior population
During the next two decades these areas will see a growing proportion of retirement age Americans, said Thomas Culliton, one of the report’s authors.

The new population data are likely to be used locally in zoning decisions, such as whether to allow single-family homes or larger condominiums to be built in a particular area, noted Richard Spinrad, director of NOAA’s National Ocean Service.

While tsunamis have drawn little public concern in the U.S., these waves are a hazard in some U.S. areas, especially in the West where a 1964 tsunami damaged much of the California coast. Crescent City was hardest hit with a 20-foot wave killing 11 people and wrecking the city’s waterfront business district. Hilo, in Hawaii, has also suffered serious tsunami damage.

The better-known threat to Eastern and Gulf coastal areas involves hurricanes. Last year hurricanes Charley, Frances, Ivan and Jeanne took turns battering Florida and other states, causing 152 deaths and billions in damage.

Vertical evacuations
One answer might be vertical evacuations that could send people fleeing upward in high-rise buildings rather than away from a stormy coast, according to these experts.

Vertical evacuation–moving people upstairs in taller structures–is a possibility in areas at risk of tsunamis, especially on the West Coast, Spinrad said. Going upstairs in a well-constructed building can be as effective as getting on the road and heading inland, he said.

Vertical evacuation has also been proposed in areas such as New Orleans where hurricanes or floods could threaten large urban areas with limited evacuation opportunities.

The NOAA study found: