NEW ORLEANS IS SINKING
BY JIM WILSON
Published on: September 11, 2001
They don't bury the dead in New Orleans. The highest point in the city is only 6 ft. above sea level, which makes for watery graves. Fearful that rotting corpses caused epidemics, the city limited ground burials in 1830. Mausoleums built on soggy cemetery grounds became the final resting place for generations. Beyond providing a macabre tourist attraction, these "cities of the dead" serve as a reminder of the Big Easy's vulnerability to flooding. The reason water rushes into graves is because New Orleans sits atop a delta made of unconsolidated material that has washed down the Mississippi River.
Think of the city as a chin jutting out, waiting for a one-two punch from Mother Nature. The first blow comes from the sky. Hurricanes plying the Gulf of Mexico push massive domes of water (storm surges) ahead of their swirling winds. After the surges hit, the second blow strikes from below. The same swampy delta ground that necessitates above-ground burials leaves water from the storm surge with no place to go but up.
The fact that New Orleans has not already sunk is a matter of luck. If slightly different paths had been followed by Hurricanes Camille, which struck in August 1969, Andrew in August 1992 or George in September 1998, today we might need scuba gear to tour the French Quarter.
"In New Orleans, you never get above sea level, so you're always going to be isolated during a strong hurricane," says Kay Wilkins of the southeast Louisiana chapter of the American Red Cross.
During a strong hurricane, the city could be inundated with water blocking all streets in and out for days, leaving people stranded without electricity and access to clean drinking water. Many also could die because the city has few buildings that could withstand the sustained 96- to 100-mph winds and 6- to 8-ft. storm surges of a Category 2 hurricane. Moving to higher elevations would be just as dangerous as staying on low ground. Had Camille, a Category 5 storm, made landfall at New Orleans, instead of losing her punch before arriving, her winds would have blown twice as hard and her storm surge would have been three times as high.
http://www.popularmechanics.com/science/research/1282151.html