As the superstorm rolled ashore along the Gulf Coast, more than 6,000 persons lost their lives in the monster hurricane s storm surge and wind. Ninety percent of the people killed in hurricanes drown as flood waters rise quickly from the storm surge and heavy rains. Flash floods from intense thunderstorms are also deadly. The fact sheet diagrams the usually fatal consequence of driving through floodwaters. Water only one foot deep flowing over a road can exert more than 500 pounds of lateral force, which sweeps an automobile into the much deeper water along the roadside, Perry said.
Floods are also the most costly of all natural disasters in the United States.
More than 55,000 homes were damaged or destroyed and 532 counties received federal disaster aid. The USGS maintains more than 7,000 gaging stations throughout the United States, Puerto Rico and the Virgin Islands to monitor streamflow. Real-time streamflow information for most of these stations can be accessed through the World Wide Web, providing flood warning for those in harm s way. These gages can also be connected directly to warning devices in flash-flood prone areas. All streamflow information is provided by the USGS to various federal, state and local cooperating agencies as well as the general public.