Wednesday, September 15, 2004
New Orleans may get 20-foot flood waters
By Brett Martel
The Associated Press
NEW ORLEANS - The worst-case scenario here - a direct strike by a full-strength Hurricane Ivan - could submerge much of this historic city treetop-deep in a stew of sewage, industrial chemicals and fire ants, and the inundation could last for weeks, experts say.
If the storm were strong enough, Ivan could drive water over the tops of the levees that protect the city from the Mississippi River and vast Lake Pontchartrain. And with the city sitting in a saucer-shaped depression that dips as much as 9 feet below sea level, there would be nowhere for all that water to drain.
Even in the best of times, New Orleans depends on a network of canals and huge pumps to keep water from accumulating inside the basin.
"Those folks who remain, should the city flood, would be exposed to all kinds of nightmares, from buildings falling apart to floating in the water having nowhere to go," Ivor van Heerden, director of Louisiana State University's Hurricane Public Health Center, said Tuesday.
LSU's hurricane experts have spent years developing computer models and taking surveys to predict what might happen.
The surveys predict that about 300,000 of the 1.6 million people living in the metropolitan area would risk staying.
The computer models show a hurricane with a wind speed of around 120 mph or more - hitting just west of New Orleans so its counterclockwise rotation could hurl the strongest surf and wind directly into the city - would push a storm surge from the Gulf of Mexico and Lake Pontchartrain over the city's levees. Ivan had sustained wind of 140 mph Tuesday.
New Orleans would be under about 20 feet of water, higher than the roofs of many of the city's homes. Besides collecting standard household and business garbage and chemicals, the flood would flow through chemical plants in the area, "so there's the potential of pretty severe contamination," van Heerden said.
Severe flooding in bayous also forces out wildlife, including poisonous snakes and stinging fire ants, which sometimes gather in floating balls carried by currents.
Much of the city would be under water for weeks. And even after the river and Lake Pontchartrain receded, the levees could trap water above sea level, meaning the Army Corps of Engineers would have to cut the levees to let the water out.
"The real big problem is the water from sea level on down because it will have to be pumped and restoring the pumps and getting them back into action could take a considerable amount of time," said John Hall, the Corps' spokesman in New Orleans.
Hall spoke from his home - 6 feet below sea level - as he prepared to flee the city. The Corps' local staff was being relocated 166 miles north to Vicksburg, Miss.
New Orleans was on the far western edge of the Gulf Coast region threatened by Ivan, and forecasters said the hurricane appeared to moving toward a track farther east, along the Mississippi coast.
If the eye came ashore east of the city, van Heerden said, New Orleans would be on the low side of the storm surge and would not likely have catastrophic flooding.
The worst storm in recent decades to hit New Orleans was Hurricane Betsy in 1965, which submerged parts of the city in water 7 feet deep and was blamed for 74 deaths in Louisiana, Mississippi and Florida. That storm was a Category 3, weaker than Ivan is expected to be.
Ivan's toll so far
Hurricane Ivan has killed at least 68 people: 15 in Jamaica, 39 in Grenada, five in Venezuela, one in Tobago, one in Barbados, four in the Dominican Republic and three in Haiti.