E-MAIL THIS LINK
To: 

New Orleans Flood protection long an issue of dispute
The 17th Street levee that gave way and led to the flooding of New Orleans was part of an intricate, aging system of barriers and pumps that was so chronically underfinanced that senior regional officials of the Army Corps of Engineers complained about it publicly for years.

Often leading the chorus was Alfred C. Naomi, a senior project manager for the corps and a 30-year veteran of efforts to waterproof a city built on slowly sinking mud, surrounded by water and periodically a target of great storms.

Mr. Naomi grew particularly frustrated this year as the Gulf Coast braced for what forecasters said would be an intense hurricane season and a nearly simultaneous $71 million cut was announced in the New Orleans district budget to guard against such storms.

He called the cut drastic in an article in New Orleans CityBusiness.

In an interview last night, Mr. Naomi said the cuts had made it impossible to complete contracts for vital upgrades that were part of the long-term plan to renovate the system.

This week, amid news of the widening breach in the 17th Street Canal, he realized that the decadeslong string of near misses had ended.

"A breach under these conditions was ultimately not surprising," he said last night. "I had hoped that we had overdesigned it to a point that it would not fail. But you can overdesign only so much, and then a failure has to come."

No one expected that weak spot to be on a canal that, if anything, had received more attention and shoring up than many other spots in the region. It did not have broad berms, but it did have strong concrete walls.

Shea Penland, director of the Pontchartrain Institute for Environmental Studies at the University of New Orleans, said that was particularly surprising because the break was "along a section that was just upgraded."

"It did not have an earthen levee," Dr. Penland said. "It had a vertical concrete wall several feel thick."

Now the corps is scrambling. After failing to close a 300-foot break in the canal through which most of the floodwater entered the city, federal engineers decided last night to take the battle with Lake Pontchartrain to the lakefront.

Starting today, they will prepare to drive corrugated vertical steel plates, called sheet pile, into the mud near where the narrow canal meets the lake, sealing it off so that the big breach farther in can be more methodically attacked, Mr. Naomi said.

The decision was made after a day of fruitless efforts to figure how to drop concrete highway barriers or huge sandbags into the torrent. For the most part, the water between the lake and the filled bowl of the city leveled off as of last night, officials said.

Weaknesses in the levee system were foreshadowed in a report in May on the hurricane protection plan for the region and the budget gap.

The district headquarters said, "The current funding shortfalls in fiscal year 2005 and fiscal year 2006 will prevent the Corps from addressing these pressing needs."

They also meant that there was far too little money to study thoroughly an upgrade of the protections from the existing standard, enough to hold back a hurricane at Category 3 on the five-step intensity scale, to a level to withstand floods and winds from a Category 5 storm.

Hurricane Katrina was on the high end of Category 4 and, despite the extreme flooding, is still seen by many hurricane experts as a near miss for New Orleans.

Since 2001, the Louisiana Congressional delegation had pushed for far more money for storm protection than the Bush administration has accepted. Now, Mr. Naomi said, all the quibbling over the storm budget, or even over full Category 5 protection, which would cost several billion dollars, seemed tragically absurd.

"It would take $2.5 billion to build a Category 5 protection system, and we're talking about tens of billions in losses, all that lost productivity, and so many lost lives and injuries and personal trauma you'll never get over," Mr. Naomi said. "People will be scarred for life by this event."

He said there were still no clear hints why the main breach in the flood barriers occurred along the 17th Street Canal, normally a conduit for vast streams of water pumped out of the perpetually waterlogged city each day and which did not take the main force of the waves roiling the lake. He said that a low spot marked on survey charts of the levees near the spot that ruptured was unrelated and that the depression was where a new bridge crossed the narrow canal near the lakefront.

Some experts studying flood prevention with the corps and other agencies speculated that any dip in the retaining levee or walls there might have allowed water to slop over and start the collapse.

Mr. Naomi said that as the power of the hurricane grew clear over the weekend, he and others who had worked to make the system as strong as it could be, given the design limits, could only hope that it would hold.

But, he said, he knew that the chances were high that the rising waters and crashing waves would find a fatal weak spot in the 350 miles of levees and walls.

As often occurs after a storm, Lake Pontchartrain is sloshing back and forth, sending pulses of water into the city and potentially complicating repairs, Dr. Penland said.

"It's like you have a bowl of water and you shake it, and it sloshes back and forth," he said, describing a phenomenon that geologists call a seiche (pronounced sesh). "Mississippi Sound and Pontchartrain are real prone to seiches when big storms come through. We are seeing the slosh. Water is being flushed through the gaps in the levees."

He said scientists at the United States Geological Survey estimated that the sloshing would gradually diminish in a few days.

Until then, the city will be subject not just to normal variation in the lake, where water levels change about a foot between high and low tide, but also to the variations of the seiche. "You have not just the one-foot tide, you probably have three to four feet of water," Dr. Penland said. "Once we get to an ordinary tidal regime, when it plays out, that will be our opportunity to close those breaks in the levees and start pumping."
Posted by: Dan Darling 2005-09-02
http://www.rantburg.com/poparticle.php?ID=128417