Louisiana’s Levees Held Up to Less Than Expected Impact of Hurricane Gustav

Mon September 08, 2008 - National Edition
Giles Lambertson




Hurricane Gustav didn’t disappoint anyone Labor Day weekend when its assault upon the environs of New Orleans proved less disastrous than the epic destruction of Hurricane Katrina three years ago.

Yet even its diminished strength was enough to uproot 2 million people, turn off the power to thousands more and send wind-whipped waters surging up and over levees and flood walls throughout the region.

Of even more significance, the hurricane was sufficiently ferocious to test all the new flood-control structures rebuilt and strengthened since Katrina.

“I think it was a good test,” said Villere Cross, project manager of the Gulf division of Manson Construction Co., two days after the storm came on land. “But then, every hurricane is a good test of walls and levees.”

The morning of Sept. 3, a day after Gustav blustered northwest and left behind blue skies and a gentle breeze, Cross and other Manson Gulf employees were beginning to reclaim their disrupted work routine. Manson’s fleet of barges and derrick and hopper dredges seemed none the worse for riding wind-tossed waters. The storm did drop trees and rip off some roofing and siding in the shop area of the Manson complex in Houma, La., 30 mi. southwest of New Orleans.

Houma and a community a little farther north, Thibodaux, were in the direct path of Gustav. Houma was still without power Sept. 3 — part of a widespread outage that had Louisiana officials fuming at Entergy New Orleans, the major power company serving the area. Gov. Bobby Jindal declared there was “no excuse” for such lingering power failure, though Entergy president Rod West seemed to offer a pretty good one: All but one of 14 high-voltage electrical transmission lines were knocked offline by the storm.

Power lines were possibly the biggest infrastructure losers across the broad path of the hurricane. Unlike in 2005, wind seemed to have caused more damage than floodwaters, though Cross and U.S. Army Corps of Engineers officials were equally cautious about assessing damage so soon after the storm.

“I’m in Thibodaux as we speak,” Cross said during a phone interview, “but I understand that all of the levees on the west bank [of Lake Cataouatche] didn’t suffer near the damage or the high water that they were expecting. Basically, what I can say at this point is that as far as I know the levees held.”

The Cataouatche levee is part of a $17 million levee enlargement project awarded Manson in early 2007. Manson’s section of the project is nearing completion and has been raised about 3 ft. (0.9 m). The company ultimately will move more than a half million cu. yd. (380,000 cu m) of granular material, compact some 230,000 cu. yd. (176,000 cu m) of clay material and distribute more than 400,000 cu. yd. (306,000 cu m) of uncompacted clay. All of the clay is being scooped up by draglines on the levee right of way.

Southeast of Cataouatche in Plaquemines Parish, which meanders for miles down each side of the Mississippi River, high water threatened a private levee. A breach developed Sept. 1 in the levee in Braithwaite and two days later was still in the process of being plugged using an estimated 350 sand bags.

North of the Mississippi in uptown New Orleans, Corps of Engineers officials also were cautiously optimistic the day after Gustav struck the city. Levees, flood gates and pump stations that were painstakingly buttressed and reconfigured after Katrina seemed to have done their job, though “seemed” was the key word. A final judgment awaited closer inspection.

“Well, you know, we are going to start some assessments on overflights and make sure everything is OK,” said Amanda Jones, public affairs specialist for the Corps. “We are going to assess every portion of the system and once we know our system is OK, we will feel relief. We do know that we survived this.”

Jones and most of the Corps staff in the New Orleans District office retreated from uptown New Orleans as the storm approached; on Sept. 2 they still were working from the Vicksburg, Miss., district office. To some extent, they were relying for their analyses on some of the same video coverage viewed by the rest of the country, such as scenes of water spraying and splashing over floodwalls on the Inner Harbor Navigation Canal.

The flooding was “very minor,” Jones tentatively concluded, certainly not enough to flood homes and inundate parishes as in 2005. “The new levee system isn’t complete yet, so we expected some minor overtopping and we did have some,” Jones said. “The system performed just as we expected it to perform.”

Jones said that though Gustav fell short of predictions, it still was “somewhat of a test” for the system and for the Corps, which immediately after Katrina had its reputation sullied by congressional inquiries. The Corps was alleged to have designed and let contractors build deficient flood control structures, which resulted in damage to 169 mi. (272 km) of the 350-mi. (563 km) hurricane flood-control system.

In June 2006, the Corps commander acknowledged “catastrophic failure” in levee design and construction. “Words alone will not restore trust in the Corps,” said Lt. Gen. Carl Strock. The scent of failure never completely evaporated in the ensuing years, which made this recent storm of special significance to the engineers.

When London Avenue and 17th Street Canal walls collapsed in 2005, much of eastern New Orleans was flooded. In early 2007, an $85 million design-build contract was awarded to Weston Solutions to increase the temporary pumping capacity at the canals. The goal was to relieve storm surge pressure on the canals’ walls from Lake Pontchartrain by pumping water around closed floodgates. The new pumps transfer water at the rate of thousands of cubic feet per second.

In May, the gates were closed on those two canals and two others and the new pumps were tested in full-scale operation. The walls, gates and pumps were deemed ready for the real thing. Gustav was the real thing.

“This is the first time we’ve ever had a need to close the gates at the mouth of London Avenue and 17th Street canals,” Jones said as Gustav headed away from the city. After a district commander made the call to close the gates, initial indications were that the strategy worked as designed.

“It is always going to depend on the size of the storm, but we have been working on this so much,” Jones said. “We knew that if we had to drop those gates and work those pumps, we were confident that our system was going to perform and it did.”

Private contractors are on call during emergencies, but they act only after Corps assessment of a situation. Because of the continuing Gulf storm crises and the ongoing canal work, the Army engineers have developed a relationship with some big companies.

Public affairs officer Maj. Tim Kurgan cited Boh Bros. Construction as a company that has done a “ton of work” for the Corps in recent years. The New Orleans-based firm is just shy of being 100 years old and has won hundreds of millions of dollars in contracts for repair work since Katrina, ranging from the 17th Street floodgate to Interstate 10 bridges. In July, the company was awarded a $62 million contract for a 1,100-ft. (335 m) section of a floodwall near Harvey Canal.

Several other sections of the same flood-control project were successfully bid by Cajun Industries, another big player in the region. In contrast to Boh Bros., the Baton Rouge, La., heavy construction company has been around only since 1973. Among its post-Katrina projects was a $6.6 million emergency contract to “unwater” New Orleans. In the following year, it won a $33 million bid to demolish and reconstruct 4,000 ft. (1,220 m) of floodwall. The company earned an Associated Builders and Contractors National Excellence in Construction award in 2006 for its repair of the floodwall along the Inner Harbor Navigational Canal.

There’s Still Work to Be Done

Boh and Cajun and several other firms will work together as subcontractors on a $695 million New Orleans floodgate project, the largest design-build civil works project in the history of the Corps. Shaw Environmental and Infrastructure Inc. is general contractor of the project, which is just beginning. The federally funded job will erect a gate-and-wall system southeast of metro New Orleans, generally between a major transportation artery called Paris Road and Lake Bourne to the east.

“We are going to build a barrier basically at the entrance to the industrial canal to stop a storm surge from ever getting into the canal,” Kurgan said. The barrier will contain “36-inch spuncast concrete piles driven into the ground side by side all the way across that area, 110 to 130 feet into the ground, sticking up out of the ground 21 feet.”

Steel columns will buttress the piling on the backside and a small inspections road will be built across the top of the barrier with a 5-ft. (1.5 m) wall protecting it, bringing the barrier’s full height to 26 ft. (7.9 m). Two gates will be built into the barrier to allow watercraft to ply the waters in that area — the smaller gate being about 75 ft. (23 m) wide and 8 ft. (2.4 m) high. That is half the size of the larger gate. When a surge is imminent, the gates will be closed.

The project is scheduled for completion in 2011. “But the key to this is that we are going to have an interim level of protection completed by hurricane season in 2009,” Kurgan explained. “We’ll have the spuncast piles in and the barge gate in by then and have protection of up to 20 feet in that area.”

Had the barrier — even the interim stage — been in place for Gustav, Kurgan said “you would not have had spillage over that Intercoastal Canal wall.”

The Corps of Engineers and private contractors have high profile roles in the ongoing flood-control work throughout the Mississippi delta region in and around New Orleans. Understandably, differences of opinion sometimes arise. Some arose, for example, in the levee project work at Lake Cataouatche.

Manson Gulf’s Villere Cross said that in meetings as recently as a week prior to Gustav’s arrival some contractors challenged the Corps’ required procedures in raising the height of the levee.

“The engineers typically require that we raise the levee in 5,000-ft. increments and that we not proceed on another increment until the first one is completed and grassed,” Cross said, a work chronology he called “ridiculous.”

“In a section 3 miles long, if you get two sections up to 15 feet and the rest are still at 12 feet, you really haven’t accomplished anything,” he said. “Whereas if you raise the entire 3-mile section 1 foot, well, 1 foot is better than no feet, and trust me the water is not going to go down where the levee starts to drop to a lower elevation.”

According to Cross, the topic was discussed thoroughly and contractors are hopeful that the work specifications will be changed for subsequent levee work.

Such workplace debates aside, the Corps of Engineers has by its own accounting overseen the moving of a lot of dirt in the last three years. More than 220 mi. (354 km) of levee structures were repaired or replaced in the nine months after Katrina struck. That and other work have cost almost $13 billion in federal money with Louisiana taxpayers contributing another $1.8 billion.

Some 45 construction projects are active throughout the district and another 23 are expected to be awarded in the next six months. Four key parishes — Orleans, Jefferson, St. Bernard and Plaquemines — contain 73 pump stations and 18 of the stations have been repaired in the last three years. Another 12 are under reconstruction. The total bill for just the pump stations is $67 million; still to come is storm-proofing of several of the stations.

The work to protect New Orleans and other low-lying communities in the delta is, if not endless, certainly without end in the foreseeable future. Nor do opportunities appear to be diminishing to test the higher and stronger flood-control barriers and more powerful discharge pumps. As Corps officials are well aware, hurricane season is young yet. Another test could boil up in the Atlantic any day. CEG