December 21, 2005

By JOHN SCHWARTZ

NEW ORLEANS, Dec. 16 - It was the canals that betrayed this city, but they never left the scene of the crime. The fingers of water that overflowed sit there like open wounds, and many residents and engineers would prefer never to see them again.

"Those canals are like knife cuts into a person," Ivor van Heerden, deputy director of the Hurricane Center at Louisiana State University, said. "They're just waiting to fester."

The Bush administration agreed last week to pay for gates to cut off the three main drainage canals from Lake Pontchartrain, the source of the storm water that pushed into the canals and then into thousands of houses.

Many here say the gates will be inadequate as long as the canals remain. Either way, it is clear that repairing the canals has become a linchpin of any plan to move the city forward.

The flood protection system failed in many places and in many ways, with water overflowing miles of levees along Lake Borgne to the east and a deadly surge funneling up the Mississippi River Gulf Outlet, a navigational shortcut that many in the state have long wanted to close.

But it is the three breaches on the 17th Street and London Avenue Canals that draw an almost obsessive interest here, because they failed even though the water levels in the storm remained well below the tops of the floodwalls.

That the canals are still there at all is in many ways a victory of complacency over common sense, as they remained virtually unchanged while the world around them was transformed by growth and new technology. They were originally built in the 19th century to carry rainwater and sewage from the city past marshland northward into the lake.

But by the 20th century, even as the canals were enhanced with powerful pumping stations and higher floodwalls, they remained open ditches that moved water through neighborhoods of houses and businesses.

Local engineers had long known the possibility of a storm surge from the lake. More than a decade ago, the Army Corps of Engineers proposed gates at the mouths of the canals as a way to strengthen the levee system. The New Orleans Sewerage and Water Board and the Orleans and Jefferson Parish levee boards killed that plan. The argument was that closed gates without adequate pumping could cause flooding in hurricanes.

After that proposal failed, the corps suggested the current system of concrete floodwalls to raise the level of the earthen levees. Now gates seem more likely to be built.

Last week, the White House announced that it would ask Congress for $1.5 billion, on top of the already requested $1.6 billion, to deal with the problems of the drainage canals.

Rainwater going the other direction would be pumped past the barriers into the lake by new pumping stations. Depending on the ultimate design, the gates might be closed permanently or be able to be closed quickly in the face of an approaching storm.

At a news conference announcing the new request, the coordinator of the federal response to Hurricanes Katrina and Rita, Donald E. Powell, said, "The levee system will be better and stronger than it ever has been in the history of New Orleans."

Is "stronger" strong enough?

Artie Folse, who lives in the Lakeview neighborhood a few blocks from the 17th Street Canal, has watched the corps repair the 465-foot breach in the canal wall with high-quality sheet piles and improved earthwork to resist the water pressure.

But, Mr. Folse said, his eyes widening, "What about the rest of it?"

The untouched levee stretches, he said, could just be another breach waiting to occur.

"It's like welding," he said. "The weakest spot is next to the weld."

Although the administration plan, if well executed, could offer greater protection for the drainage canals - and Artie Folse's neighborhood - it is unclear the extent to which they will raise protection levels at the eastern end of the city, where so many miles of levee were destroyed by the rushing waters of Hurricane Katrina.

Water is still likely to course over the tops of the eastern levees if a storm as strong as Hurricane Katrina hits New Orleans directly, instead of passing to the east as Hurricane Katrina did, engineers say.

"The thing that scares me about open water channels is your inability to control them," said Robert G. Bea, a professor in the department of civil and environmental engineering at the University of California, Berkeley, who has studied the system and favors replacing the canals with enormous underground culverts.

"Cover the suckers," Professor Bea said. "Turn this into something we can control, manage and maintain, and let that part of the world get on with its life."

Dan Hitchings, director of Task Force Hope, the Hurricane Katrina relief effort of the Army Corps of Engineers, said the planned repairs and upgrades would give New Orleans greater protection, but would still be a far cry from the Category 5 storm protection that many residents have demanded. More likely, Mr. Hitchings said, the work would protect against the 100-mile-an-hour winds of a Category 2 hurricane and the low barometric pressure - a contributor to storm surges - of a Category 3 or weak Category 4 storm.

Additional protection can be installed after that work has been completed, he said.

The White House proposals have little to do with the damage caused when storm waters destroyed levees at the Mississippi River Gulf Outlet, a channel east of New Orleans in St. Bernard Parish that allows ships a shorter route between the river and the Gulf of Mexico.

Locally, many elected officials have reached a consensus that this channel, known familiarly by the acronym Mr. Go, should be closed. For years it has been little used, and it serves as a conduit for destructive saltwater into freshwater wetlands.

"I think this event has proved how dangerous and deadly a hurricane alley Mr. Go is," Senator David Vitter, Republican of Louisiana, said.

Officials at the Port of New Orleans disagree, and want the outlet preserved. For now, the corps has announced that it will not dredge Mr. Go next year, waiting for its future to be determined.

The port has struck an accord with St. Bernard Parish that calls for a floodgate and the eventual closing of the channel to "deep draft" vessels, so long as the businesses along it are moved and a new lock can be built.

Back in Lakeview, Mr. Folse said he hoped to bring his family home, but only after the corps addressed the canal problem. He favors closing the canals and said he expected the work to be carried out.

"Politically, nobody can afford to let this happen again," he said.

He was both optimistic and fatalistic. If there are no hurricanes before the safety upgrades are in place, he said, "we'll be O.K."

Then he added: "What else we going to do? Everything we have is tied up in this."