August 29, 2005

As the eye of Hurricane Katrina passed over New Orleans during the morning of Aug. 29, officials had closed all major routes, including the 32-mile causeway and the twin spans of Interstate 10 across Lake Ponchartrain, says a Louisiana Dept. of Transportation and Development. Reports of 4-ft-high flooding on U.S. 90 and 3 ft of flooding in some canals were expected, says Mark Lambert, LADOTD spokesman, speaking by cell phone and without electricity. "The storm is at this moment getting closer," he said at about 10:30 a.m. "It's very hard to assess anything right now."

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While most of the highways are built to withstand major hurricanes, the possibility of flying debris causing damage is a big concern, and several old moveable bridges may be at risk, he adds. The biggest transportation item of concern right now is an old nine-mile connector of LA 1 to Port Fourchon. The connector carries 18% of the nation's oil and gas supply. Moreover, the connector links to Grand Isle's Barrier Island, which is inhabited. "We are almost certain that the whole connector may be underwater," says Lambert. Ironically, the LADOTD was in the middle of conducting a report to investigate why two bids this July to replace—and elevate—the connector came in $100 million over engineers' estimate of $154 million (ENR 7/18, p. 13). The new connector would be 22.5 ft high.

Winds, estimated at 150 miles per hour, ripped two holes in the roof of the Superdome early Monday. By midday, ground-level witnesses counted up to 60 gaps in the ceiling. The vast structure, with 77,000 seats, is New Orleans' main storm shelter, currently home to 8,000 to 9,000 residents who were unable or unwilling to heed the mandatory evacuation order.

An engineer who inspected the roof at the request of Gov. Kathleen Blanco (D) declared it sound, according to news reports.

Strips of metal began peeling away from the roof early on the morning of Aug. 29, and numerous other leaks were reported as well. But damage appears to be limited so far to the roofing material.

Designed by Curtis and Davis Architects and Planners and built in 1973 by Huber Hunt and Nichols, now part of Phoenix-based Hunt Group, the Superdome was roofed with steel framing covered with polyurethane. The roof's sprayed-on Hypalon membrane was damaged in 1980 by a freak hailstorm. By the time a decision was made to proceed with repair, the original estimate of $450,000 had ballooned to $4.5 million, in part because of subsequent corrosion of the steel members (Engineering News-Record 8/5/82 p. 11).

The state and the building's insurer, Reliance Insurance Co., Philadelphia, reached a settlement in 1987 for $2.7 million to repair the roof (Engineering News-Record 2/12/87 p. 16). An architectural firm that recently studied the Superdome's interior, but not its roof, says that the roof may have been replaced two or three years ago.

The U.S. Army Corps of Engineers New Orleans District instructed its personnel to evacuate the city on Saturday. Many of the 1,500 employees headed for the Corps Mississippi Valley headquarters in Vicksburg, Miss. On Monday morning the Corps was establishing a hurricane command center there and coordinating recovery operations and monitoring operations of the Mississippi River levee system. Water was overtopping the Industrial Canal lock walls on the East Bank of the city, reported John Hall, Corps public affairs officer, “But so far the structure is holding,” he said.

The Industrial Canal Lock, which spills water from Lake Ponchartrain when necessary, is one of the busiest in the world. The busy trade link connects the Mississippi River, the Gulf Intracoastal Waterway, the Mississippi River-Gulf Outlet, the Inner Harbor Navigation Canal and Lake Ponchartrain. Congestion is common; barge strings often wait up to 36 hours to pass through the lock, which measures 75 ft x 640 ft x 31.5 ft. Plans are under way to expand the dimensions to 110 ft x 1200 f x 36 ft, but concerns about wetlands loss and displacement of residents have delayed the project.

New Orleans Mayor Ray Nagin, in an interview with NBC about 11:30 a.m. Monday, says it looks like the levees are holding, although water has come over the top in the 9th Ward, in southeast part of New Orleans. There is substantial flooding in that area. He also reported one pumping station has stopped operating, but for the most part the flood control system is holding.

Further east, Mississippi officials say there are reports of inundations of numerous portions of Interstate 10 paralleling the Gulf coast.

The New Orleans airport was closed and calls to the Port of New Orleans could not be completed due to busy circuits.

The list of counties and parishes eligible for Federal disaster assistance is growing as Hurricane Katrina passes through. Added Monday to 38 parishes in Louisiana declared eligible even before the storm came ashore were 11 counties in Mississippi and six counties in Alabama, as well as two heavily populated counties in South Florida, Broward and Miami ­ Dade, that were hit Aug. 24.

Michael D. Brown, Under Secretary of Homeland Security for Emergency Preparedness and Response, says the federal funding is available to state and eligible local governments and certain private nonprofit organizations on a cost-sharing basis for debris removal and emergency measures.

For a period of up to 72 hours, federal funding is available at 100 per cent of the total eligible costs for emergency protective measures, excluding debris removal. After the initial period, federal funds are available for public safety debris removal and emergency protective measures at 75 percent of approved costs.

Brown said the declaration also makes cost-shared funding available for approved projects that reduce future disaster risks. FEMA is mobilizing equipment and resources to assist law enforcement with evacuations, establishing shelters, and meeting other emergency needs.

ENR team coverage

Related Links:

Katrina's Worst May Not Hit New Orleans posted Aug. 29, 2005
Superdome Roof Peels Off posted August 29, 2005
Katrina Collapses Miami Overpass Under Construction 08/26/2005