"We've got to keep the water out, because there is no downhill for water to run from here," said Baylor Lansden, the managing director of the Orleans Parish Levee District, the government agency that maintains a 131-mile wall around this city.

As Hurricane Andrew came calling with sheets of driving rain yesterday, the onslaught was met by flood walls and earthen mounds that towered as much as 20 feet above the surrounding neighborhoods.

"If you live here, you just don't think too much about living below sea level," said Lansden, who paused and added: "Well, on days like this, you do."

Lansden yesterday stood in the Levee District's headquarters on the Pontchartrain lakefront as leaden skies whipped up the waves outside the windows. Engineers snacked on cold hamburgers from a grease-stained box and watched computers tracking Hurricane Andrew's course. The levee watchers had a long night ahead.

"We're here for the duration," said Lansden.

Since the earliest French settlers built New Orleans at the mouth of the Mississippi to control access to the river, the inhabitants of this city have debated the wisdom of living in a saucer surrounded by swamps.

"Some people have said that the founder of the city was a damn fine real estate salesman, but not a very good engineer," said Lansden.

On average, New Orleans lies five feet below sea level - homeowners here know precisely the level at which their houses lie because their flood insurance depends on it.

With sea level at eye level of the average New Orleans resident, then the Mississippi River, which lumbers through the city behind massive levees, is higher still - well above the surrounding landscape.

"You don't go down to the river here, you go up," said Lansden.

In most cities, rainfall runs into sewers and then drains into rivers. Not in New Orleans. Any water that spills on the streets eventually must be pumped up and over a levee. The pumps operate on generators so they can continue working during power failures.

The soil beneath New Orleans is so saturated that the dead are interred in crypts above ground. But the flood control system of pumps and canals has effectively drained the city so that the soil is subsiding and the city is sinking even farther below sea level.

"The soil has shrunk, in effect," said Walter Judlin, a project manager for the U.S. Army Corps of Engineers who has overseen the construction of hurricane levees that protect the parishes around Lake Pontchartrain.

Yesterday, workers closed the last of 111 massive steel gates that form the openings through which streets and railroads breach the levees when the weather is dry. Closing the gates virtually shuts down rail traffic in the city.

The walls have literally become a part of the fabric of the city. They comprise parks or form the foundations for scenic drives. In some cases, the levee district built 10-inch-thick concrete walls where it could not fit an earthen mound. In one case, it incorporated a flood wall into the side of a factory.

Engineers are concerned that all that planning would be for naught if a massive storm surge sent Lake Pontchartrain over its walls, overwhelming the ability of the pumps to drain the city.

But they say such a flood would require a storm surge of at least 12 feet, a threat only if Andrew scored a direct hit on New Orleans.

Lansden pulled a map from his pocket that had Andrew's projected path skirting New Orleans by a wide margin.

"You might be able to plot a ship or an airplane in a straight line like that, but not a hurricane," he said.

As Judlin noted, preventative measures can go only so far.

"When the storm the size of Andrew hits the Louisiana coast, somebody is going to get hurt," he said. "That's part of living down here.