As hurricane Katrina bore down on the French Quarter on Monday, engineers and a special force called the Levee Police kept a windy vigil on the ramparts that were supposed to keep New Orleans from sinking.
Most of those defenses worked - barely. Despite catastrophic predictions and with a few notable exceptions, levees held, pumps sputtered, stopped, and started again. As the storm suddenly veered to the east then moved northward, people began venturing out, finding a city swamped and battered but not defeated - a miracle of hydraulic intervention.
Katrina was a long-awaited test for one of the world's unique, though unfinished, public works. While it showed that the city could survive a major hurricane, it also exposed its vulnerability to flooding and the weaknesses of its pumping system. Those problems are renewing a debate over whether officials need a new strategy to beat back future storms and if it should require even stronger barricades of cement and steel or restoring wetlands to absorb water.
"The question over the next months will be: How did our efforts to mitigate this measure up?" says environmental sciences professor John Pine, who heads the Disaster Science and Management program at LSU. "It's quite a test, and building bigger seawalls may not be the only answer."
An American Venice, New Orleans first began fighting water with earth in 1807, under the French. Now 125 miles of levees and 126 storm gates ring the city, a project that from the start has been a dance with destruction and which gave the city part of its spooky charm.
Flanked to the south by the Mississippi River and to the north by Lake Ponchartrain, New Orleans is a major US port and oil refinery, a crucial national asset beyond po' boy sandwiches and smoky jazz. After each flood, and near-catastrophe, from the 1927 floods to hurricane Betsy in 1965, Category 3, the government has authorized more money to bolster the city's defenses. But through attempts to contain the mighty Mississippi, engineers also raised the stakes when they, in essence, "fixed" the Mississippi in place to keep it from meandering across the Delta. But now, when floods wrack the Midwest or hurricanes tear up through the Gulf, the city of New Orleans is faced with holding an angry snake by its tail.
"New Orleans is so physically vulnerable, and there have been attempts to mitigate that, but the vulnerability persists," says Jeanne Hurlbert, a Louisiana State University sociologist who has studied the effects of storms on the local populace.
Katrina has been the toughest test yet. At press time, Mayor C. Ray Nagin had issued a statement reporting 80 percent of the city was under water. The death toll in a neighboring Mississippi county could be as high as 80, according to Gov. Haley Barbour.
"They're getting hit with the storm that the Corps of Engineers designed the system for," says Rick Van Bruggen, a hydrology expert in Los Gatos, Calif., on the Russian River. "At the time you need it, you don't know where the weak points are, and you'll find out where some of these failures are."
The storm's slight hitch to the east largely spared the city, but the damage was still extensive as water poured through the streets. The main flooding, as predicted, came from a shipping canal in the east part of New Orleans, which resulted in problems in the 9th Ward, and damage to the St. Bernard Parish. The Levee Police, as well as Federal Emergency Management Agency and Corps personnel in oil-gear, stood sentry. Authorities also reported a levee breach in the western part of the city. A levee along the south shore of Lake Pontchartrain gave way forcing dozens of residents to flee or scramble to rooftops.
"The pumps are strategically placed to move the water back into canals, but when Ponchartrain gets so high, there's no where to put the water," says Mr. Pine.
New Orleans may take months to dry out.
While they can't do much if the levees break, dozens of electric and diesel pumps, both aging and new, are set up in the deepest hollows of the city, attached to a basin system. They are vitally important: When the 9th Ward pumps were disabled, some neighborhoods went under 10 feet of water as residents took to the rooftops. To critics, the rickety pump system shows how vulnerable the system is.
"When it comes to a storm like this, the pumps are mission impossible," says Ivor van Heerden, director of the Hurricane Center at Louisiana State University. "Number one, they aren't safe for the operators and the second thing is that you need very powerful systems with a very good electrical supply, but the more robust [a storm] is, the harder it is to operate [a pump]. As soon as you start that pump, every bit of trash that gets into the canal gets sucked into the pump. And as soon as buildings start coming apart, the level of debris shoots up dramatically."
Also raising the stakes is the fact that, for many in New Orleans, leaving is not an option: Some 50,000 households are without cars in the city, many of which made up the 9,000 people who fled to the Superdome to seek refuge from the storm.
"There's a strong perception in New Orleans that we don't leave," says Ms. Hurlbert, the LSU sociologist. "But it troubles me when I see reports of people who had no choice.... The fact is, if you're economically disadvantaged, you're more likely to be worried about looting [and] protecting your home, which all makes it much more difficult for [people] to leave."
But since 1992, federal improvements to the levee and canal system have yielded results. New pumping stations and canal improvements in Jefferson Parish, for example, seem to have helped thwart problems, even from a giant like Katrina.
At the same time, others say ramparts and pumps aren't enough. For one, New Orleans is slowly sinking, at a time when the region is annually losing 24 square miles of wetlands, which act as giant sponges to contain water during big storms. Katrina will likely yield more reinforcements, and may give further fuel to an idea to place enormous floodgates at the mouth of Lake Ponchartrain. Others envision an expensive Everglades-style project to restore thousands of acres of wetlands to absorb floods and surges. At any rate, the government, experts say, is slowly realizing the limits of the levee-and-canal system.
"The Corps has started to realize that, often at the call of the people and legislatures, they have done projects to tame rivers ... and not looking at them as dynamic environmental systems that can't be tamed," says Mr. Van Bruggen.
• Wire material was used in this report.