Water May Linger for Months

Draining the billions of gallons of water that have inundated New Orleans could take three to six months, substantially longer than some experts have expected, the Army Corps of Engineers said late Wednesday.

Col. Richard Wagenaar, the corps’ senior official in New Orleans, said that the estimate was based on planning done as Hurricane Katrina approached and that it remained the corps’ best estimate. He is directing the agency’s recovery efforts.

The estimate depends on favorable weather. Additional rain or other problems could cause more delays, Wagenaar warned.

“There is a lot of water here,” he said. “The news cameras do not do it justice. And I’m worried the worst is yet to come.”

Public officials, meanwhile, were furious over the corps’ delays. Mayor C. Ray Nagin blistered officials on television for what he called their inaction. Gov. Kathleen Babineaux Blanco scowled in irritation, saying, “I’m extremely upset about it.”

Walter Baumy, a chief engineer, said that the corps was confronted by riverbeds clogged with loose barges and debris and that it could not find contractors able to maneuver heavy equipment into the flood zone. Blanco acknowledged that officials were also struggling with faulty communication. After a disheartening aerial tour of the flooded city, Blanco said she was able to reach White House officials on a satellite phone but could not connect with Army and other officials in nearby Baton Rouge.

“Part of our problem is we’re not getting information delivered quickly enough,” she said.

Wagenaar said the evaluations Wednesday were sobering, leading him to believe that city officials’ horrific death estimates given could be accurate.

The water is 30 feet deep or more in some parts of the city, covering homes. In the city’s 9th Ward, homes have shifted and floated away, leaving nothing that resembled the city grid before the storm, Wagenaar said after a helicopter tour.

New Orleans’ lakes and rivers are bordered by a system of earthen levees, concrete seawalls and steel doors that are supposed to protect homes and businesses during heavy rains or hurricanes.

The city’s 22 pumping stations are not operating, and most are underwater. Not until the city naturally drains a little can the corps begin restoring pumping capacity, Wagenaar said.

He said the corps planned to punch holes in levees around the city to hasten the drainage now occurring through the main breach that swamped the city after the hurricane. Levees on the Mississippi River, Lake Pontchartrain and an inner coastal waterway are to be broken open in coming days, though “we haven’t decided yet how.”

The pumps, which the corps will repair when it can, are a key part of the sophisticated drainage system that is supposed to keep the city dry. But they run on electricity, which is out in the city, and the pump stations’ emergency power supplies may also need repair.

The first task, though, is fixing the main breach, on the 17th Street Canal, which leads from the city center to Lake Pontchartrain. The corps started to drop massive sandbags from military helicopters Wednesday.

The corps is also trying to build a road above the water to the breach, which is estimated to be 200 to 300 feet wide, and it is shutting off the 17th Street Canal to prevent any further water from flowing into the city, Wagenaar added. A contractor will use sheet piling to shut off the canal.

Corps officials think water rose over the top of the canal wall and cascaded down to its base, scouring a hole that undermined the foundation, said Al Naomi, the corps’ senior project engineer in New Orleans.

“It exceeded the design surge,” he said. “It just blew out the wall.”

The dirt levees and reinforced concrete flood walls are designed to hold back an 11 1/2 -foot storm surge, not including waves spilling over the top. The Katrina surge is believed to have been significantly higher than that.

The flood walls and levees are 13 to 19 feet above sea level, depending on how vulnerable the area is.

The 17th Street Canal pumping station is the largest single drainage pump in the world, able to move 10,000 cubic feet of water per second. That’s roughly how fast the Colorado River flows below Hoover Dam.

Although the Army Corps of Engineers builds and maintains the area’s levees and flood walls, parishes and cities control the pumping stations.

The water level in Lake Pontchartrain, which was unusually high after the storm, dropped 2 feet in a 24-hour period Tuesday, said Dana Newsome of the state Department of Transportation and Development. “Obviously that means the water did go somewhere.”

The corps began preparing Wednesday to fix the walls by dropping massive sandbags from Chinook helicopters, but nobody is sure the unprecedented plan to drop 500 bags will work.

New Orleans relies on the complex plumbing and flood control system to protect a city that is as much as 10 feet below sea level but surrounded by two lakes and a massive coastal flood plain as well as bisected by North America’s largest river. In much of the city, the Mississippi River flows in an elevated levee above the city and above Lake Pontchartrain.

The city has two major levee systems, one that controls periodic flooding of the Mississippi River and a second to protect against storm surges.

The river levees are nearly 100 years old, and corps officials are confident they could handle any flood the Midwest could send its way. But the hurricane barriers are another matter.

The storm wall system was begun in earnest 40 years ago, after Hurricane Betsy pummeled New Orleans. After that storm, Congress passed the Flood Control Act of 1965 and provided funds to increase the height of levees. But the work was based on hurricane surge estimates created by the National Weather Service. In recent years, it has become increasingly clear those calculations vastly underestimated the city’s vulnerability.

A mathematical model on storm surges pioneered by Notre Dame University professor Joannes Westerink increased concern that the levee system was exposing New Orleans to a major catastrophe in the case of any storm bigger than a Category 3.

“In a slow-moving Category 5 hurricane, the levees are not going to hold,” Westerink said.

As Katrina demonstrated, a Category 4 storm would also cause a massive public works failure. And the problems facing the Louisiana coast are growing more serious.

The levees and channels built to control the Mississippi River have diverted sediments that would normally replenish the Mississippi Delta and allow the region to slowly recover. At the same time, ocean levels are rising each year, making the area more vulnerable to storm surges.

The vast coastal wetlands that once protected New Orleans have also undergone development and environmental degradation.

The Bush administration last year downscaled a Louisiana request to upgrade its storm protection system.

Naomi said the corps could build a system that would protect the entire city without any natural barriers against even a Category 5 storm.

A $2-billion levee system, currently under study, could protect the coastline east to the Mississippi state line, Naomi said. Depending on the rate of spending, the system could take 30 years to build.

“We have far exceeded that amount of money in damages in just one storm surge,” he said.

Professor Joseph Suhayda, a Louisiana State University engineer, has in the past advocated building a haven in the core of New Orleans with a high wall to protect the central business district and key hospitals.

In this case, it would have given tens of thousands of residents access to a dry island in the flood.

Suhayda’s proposal was met with criticism.

Times staff writer Ellen Barry contributed to this report.