Plans didn't account for area's subsidenceMay 1, 2006 | www.nola.com
As they completed sections of the New Orleans area's hurricane protection system in the 1980s and '90s, Army Corps of Engineers officials assured residents the structures had been raised to standards mandated by Congress.
That, however, was mostly a legal fiction, documents and interviews with current and former corps employees show.
The corps' levees and floodwalls might have met specifications in the plans, but the engineers involved knew the measuring stick being used was out of date.
In fact, many sections of the system were a foot or more below authorized heights because the local office of the corps made a decision in 1985 not to use updated elevation values for projects then under way.
Some engineers familiar with the history of the project, such as the former head of the office's survey section, Wayne Weiser, say the decision was a planned deception that left people unprotected.
Others, including J. David Rogers, a forensic engineer working with one of the independent investigations of the Hurricane Katrina disaster, say the corps probably did the best it could in dealing with a complicated and sprawling project.
But they agree the story highlights a critical problem that continues to bedevil the corps and stands in the way of adequate hurricane protection for New Orleans even today.
"When you look into this story," Rogers said, "you'll see a lot of things that should have been addressed a long time ago, but are still out there at the bottom of a lot of problems."
The story begins in 1985, when Frederick Chatry was in one of the hottest seats at the corps. He was chief of engineering for the New Orleans District, the man charged with using a set budget to raise permanent hurricane protection for a city built on a constantly sinking landscape.
The decision he faced that July was a classic example. The National Geodetic Survey, the government agency that establishes baseline elevations for the nation, had just issued a new set of values for its benchmarks in New Orleans. Most of them were lower than the values Chatry's office had been using to build about 300 miles of levees and floodwalls in the region since the project was authorized in 1965. That meant what had been 12 feet high before the National Geodetic Survey announcement might now be 11 feet or less.
What to do?
Chatry, who is deceased, tried a Solomonic approach. He told his office to use the new heights for any future projects but to stick with the original elevations on projects under way, which included the local hurricane protection work that was started in 1965 and was still many years from completion.
That decision is now the topic of heated debate, because although it allowed Chatry to complete large sections of the project, it also meant that most of it would be below the heights authorized by Congress.
In a memo to superiors at the corps' Vicksburg, Miss., office, which he would later lead, Chatry made clear that the reasons for his decisions were based in pragmatism. If he were to mandate use of the new levels on a project that was only partially completed, the corps would be faced with one of two problems: Either the new sections would be higher than those already completed, resulting in uneven levels of protection and spots where structures of two different heights would meet, creating weak spots in the design; or the corps would have to go back and raise the old sections to the newly established elevations, a process that would be both time-consuming and expensive, requiring more financing from Congress and local governments.
Also, he noted that since the National Geodetic Survey revision, local agencies had done their own releveling and had come up with figures that were even lower. Where does one stop?
So he decided.
"Modification of projects which have been completed will not be considered," Chatry wrote. "The level of precision in the current data and the practical difficulty and cost of changing such projects combine to mandate this course of action at least for the foreseeable future."
Furthermore, the hurricane protection projects still under construction would stick with the levels used when they were started in the 1970s.
'False sense of security'
To Weiser, the decision meant residents never got the protection ordered by Congress and assumed by the public.
"The public never got the protection they thought they were getting, it gave them a false sense of security, and it caught up with them last year," Weiser said.
The decision "ordered us to ignore the problems caused by subsidence. All the projects completed under that rule that were certified to be in compliance with the (congressionally) authorized heights were significantly inadequate."
Weiser, who worked for Chatry at the time, said he urged him to order an immediate releveling of all the benchmarks in the New Orleans district and point out the problems to Congress for financing to build the projects to the correct height.
"Never happened," he said. "It would have meant that 90 percent of the work that had been done was 'unfinished' and had to be completed. It was the correct thing to do, but you're talking millions of dollars.
"Well, Mr. Chatry was my boss he was as high as I could go. That was it."
Al Naomi, senior project manager for the corps' New Orleans office, said it was the practical choice.
"I'm not saying I endorse his decision, but I'm saying he probably saw this as what he had to do to continue to finish the projects," Naomi said. "To apply the new levels would mean going back and correcting most of what you had done. And to do that, you would have had to ask for more funding not just from Congress, but from the local partners -- most of whom were already having trouble meeting their current obligations.
"This project was authorized in 1965, and it was already 1985, and it wasn't near finished. He was thinking, 'If we apply the (new levels), we could be waiting another 10 or 20 years to finish this thing, which means the people of New Orleans wait that long for protection.'
"And that wouldn't be the end of it. We all know this place subsides. So who's to say a new level won't be issued in another five years, and you're going back again?"
As the system was completed, most of the engineers involved knew the heights published were based on National Geodetic Survey levels that had been out of date for many years. That knowledge was shared by most private engineers and surveyors in the area, who rely on the corps to provide the latest survey levels for their own jobs.
"We're required by law to give out the latest levels published in the (National Geodetic Survey) book, and that's what we gave to anyone who called," Weiser said. "But those people knew any (corps) projects that dated before 1983 were using levels that were way out of date. They knew because they ran into them all the time."
A constant problem
They also knew because any surveying in Louisiana is a risky business because of the problem of constant subsidence. Even the latest National Geodetic Survey levels could be out of date within a year.
Roy Dokka, an LSU geologist who recently completed updating levels across the state for the National Geodetic Survey, said the lack of precise data in the state is so notorious is has become the source of black humor among surveyors. "The old joke goes, 'All the elevations in Louisiana were legal, but they were just wrong,' "Dokka said. "When you first read Chatry's letter, you're shocked until you know more about the background and the state.
"I'm not saying he made the right choice. I'm saying it's more understandable when you know the conditions here."
But until recently that reality was not recognized by the plans handed to the corps, Naomi and others said. The 1965 legislation authorizing the Lake Pontchartrain and Vicinity Hurricane Protection Project made no allowances for subsidence. There is no language or financing available for the constant repairs and raising that engineers working in New Orleans know will be required. That tradition was changed in 1986, when Congress authorized the West Bank Hurricane Protection Plan, which included allowances for subsidence.
Rogers, part of the independent levee investigation team financed by grants from the National Science Foundation and the University of California, Berkeley, said the various agencies working on future protection for south Louisiana must include similar allowances.
"Chatry's situation really highlights the problem the corps is facing down there trying to provide the level of protection people are expecting and assuming they have," he said. "Congress has never really addressed subsidence as a key issue. They give (the corps) a budget for building a project, and they think when they cut the ribbon it's over when it's not. Subsidence down there never stops, so you're never finished."
It is unclear how Chatry's decision affected protection during Katrina. The corps' ongoing investigation into the failures during Katrina already has reported many structures were below authorized heights when the storm hit. Those differences ranged from a few inches to as much as 2 feet on the Industrial Canal, where floodwalls that were on the books at 14 feet above sea level measured only 12 feet above sea level.
Naomi said the corps in 2001 surveyed all levees using the latest National Geodetic Survey levels, and found most were below design heights. But he said none that failed during Katrina were more than 1 foot lower than the authorized height. He said that since Katrina's surge was measured at up to 3 feet above those heights, the discrepancies played little or no part in the disaster. However, Weiser said levees that were overtopped but stayed intact could have stopped flooding earlier if they had been built and maintained at the authorized heights.
Either way, Naomi said, New Orleans' fate during Katrina was not written by Chatry in 1985, but by Congress 20 years earlier.
"This story was written when Congress decided on the level of protection for this city back in 1965," he said. "When they decided on the level of protection for flooding form the river, they spent billions. When they decided on a level of protection for hurricanes, they hundreds of millions.
"(Chatry's ) standards were the standards to what was authorized. Those standards did not protect against a storm like Katrina."