The city of New Orleans can be rebuilt at its present location, and safely withstand future floods and hurricanes, if it follows special building codes for its homes and commercial buildings — and rebuilds its levees using steel pilings as many engineers have long suggested.
That’s the conclusion from interviews with building code leaders by Construction Equipment Guide.
“New Orleans is way behind in any kind of [building] code, code enforcement and levee protection” said Herbert Saffir, a consulting engineer in Coral Gables, FL, who played a leading role in developing the South Florida Building Code, one of the most advanced codes in the United States.
Saffir said the future city “could be made flood-proof; it could absolutely be adequate by improving the levees.”
“They absolutely have to put in steel sheet pilings,” he said. “The pilings would be driven down, perhaps with concrete encasements. The levees did not break because of wave action; they breached because of pressure from the buildup of water.”
Example of Lake Okeechobee
Saffir said New Orleans could be ringed with successful levees as in Holland and as was done after a hurricane caused Lake Okeechobee to overflow in 1928, drowning 2,000 people. Located west of Palm Beach, FL, Okeechobee is the largest natural lake in the United States.
“The Army Corps of Engineers put a very strong and adequate levee around the lake and they haven’t had any flooding since,” he said. “The levee system in New Orleans is really set up for flooding from the Mississippi River, not from hurricanes. Any kind of even Category 3 hurricane could cause tremendous damage, but they haven’t planned for it; they haven’t thought about it; they’ve written about it, but that’s as far as it goes.
“I think all of that flooding [after Hurricane Katrina] could have been prevented. They didn’t improve the levees even though an article in Civil Engineering Magazine, published by the American Society of Civil Engineers, said two years ago that, in a Category 3 hurricane, the city would be flooded and could have approximately 20 ft. of water. The emphasis has to start locally and local people haven’t pushed for it too much.”
Updated or New Building Codes Necessary
As it rebuilds, protected by new levees, employing an army of all types of contractors, New Orleans will now have to follow building codes that mandate new, life-saving, flood and wind protection, experts said.
“It’s absolutely necessary that they follow a tough code and code enforcement,” Saffir said.
“One of the criteria for obtaining Federal Emergency Management Agency funds for reconstruction after a natural disaster is that the codes and standards that apply to the reconstruction have to be up to the [latest] national standards,” said Richard Bukowski, senior engineer of the Building and Fire Research Laboratory of the National Institute of Standards and Technology in Gaithersburg, MD.
“It would certainly be somewhat foolish to not adopt the latest, most contemporary, code in the rebuilding effort,” said Paul Myers, president of the International Building Code Foundation (IBCF) in Cincinnati, OH. A subsidiary of the International Code Council (ICC) in Falls Church, VA, IBCF is dedicated to reducing and changing the devastating effects of natural disasters by encouraging better construction methods.
“New building codes include updated criteria for just about every natural disaster, from earthquakes to high winds, airborne debris and flooding,” Myers said. “If you are in a hurricane zone, there are certain requirements for your structure that may be more stringent than a less-active zone.”
Contractors building new homes in New Orleans would thus have to meet stringent specifications for everything from foundations, rooftop tie-downs minimizing the “uplift” effect from winds, to floodproofing, fasteners, hurricane shutters and high-impact glass.
“New codes incorporate flood-proofing methods that you can build into your structure if you are in a flood plain,” Myers said. “They allow water to flow through the building, or you have to build them higher so water doesn’t do any damage. Electrical and mechanical systems, for instance, would not be in the basement. They would perhaps be placed in the attic, or second or third floor, depending on the structure.”
The code in coastal areas of Florida subject to flooding or tidal surges requires the finished floor to be above the flood level and this provision, too, could be part of the code for New Orleans.
“I really don’t think they have much choice about where to rebuild,” said Gene Corley, senior vice president of the CTL Group in Skokie, IL, who served as a principal investigator for the ASCE on both the World Trade Center and Oklahoma City attacks. “I think they can build levees that can hold back the water. Once they do that, there’s really no reason to not build back on those low-lying areas.”
Did Not Follow 2000 Residential Code
Jennifer Gibson, a spokesperson of ICC in Chicago, IL, said that New Orleans does not use the 2000 International Residential Code (IRC), with its updated flood and wind protection provisions. The IRC, a separate, standalone, code, covers one- or two-story dwellings or townhouses.
“Generally speaking, there’s not a whole lot of code use in the New Orleans area,” she said.
Many of the homes and other buildings in New Orleans are older structures, which may have been built under an older “legacy” code, or no code. An estimated 150,000 properties were lost to the flood and the total economic toll of the disaster has been estimated at more than $100 billion.
New Orleans, along with the rest of Louisiana, did adopt the 2000 International Building Code (IBC), which is for commercial structures.
Established in 1994, the ICC develops and promulgates comprehensive national model construction codes that can be used throughout the nation. Some states have mandatory codes, which all jurisdictions must adopt. Others allow local jurisdictions to adopt what they wish, perhaps deciding against a code because it could add to the cost of construction. ICC published its first codes in 2000 and updates them every three years.
New Orleans did not suffer great damage from Hurricane Katrina’s winds. The city was on the west quadrant, the weakest side, of the hurricane.
“Though the Hyatt Hotel lost all its windows, this has been attributed to just poor, inadequate, design,” Saffir said.
Building codes for the new city will almost certainly include strong requirements protecting against even Category 5 hurricane winds.
Code provisions might follow the example of the South Florida Building Code, the uniform code, which Dade and Broward counties in Florida independently developed and adopted. Covering the counties and approximately 20 municipalities, this code is regarded as the most advanced in the United States for protection against hurricane winds.
More advanced than the building code, which the rest of Florida adopted Sept. 1, the South Florida Code requires hurricane resistance in the form of poured-concrete tie beams.
“Two Number 5 bars on the top and bottom give great rigidity and transfer strength to an ordinary one or two story building,” said Saffir, who wrote the code’s wind-load section. “Roof trusses and roof rafters are anchored into the tie beam so the whole structure is something of a monolithic frame, which puts wind force into the ground. The tie beam is anchored into the foundation, which is a continuous footing of a similar reinforced concrete.”
The code spells out specification-type requirements for one-story and two-story buildings — the concrete bar structures that are now prevalent in Miami, FL, and Fort Lauderdale, FL, and includes strong prescriptive requirements for what constitutes a concrete tie beam and concrete footing in a one-story building.
“We are permitted to go beyond the state code in certain respects,” Saffir said. “We pioneered also in setting up a product approval department, which has to approve different products like roofing, windows, glass or any kind of proprietary product.”
Saffir heads Herbert Saffir Consulting Engineers, specializing in structural work, in Coral Gables, FL.
“A lot more has to be done, absolutely, in adopting adequate building codes,” he said. “Most areas, especially in Florida, are weak in hurricane resistance.”
Out of Devastation - Better Structures
Past experience strongly suggests that a much-safer New Orleans will emerge from reconstruction.
“In Florida, after Hurricane Andrew in 1992, a lot of reconstruction was better than what had been there before because it had to be built to newer codes,” said NIST’s Bukowski. “When the next hurricane came along, these communities did very well. I suspect the same thing will happen along the Gulf now because, particularly if you’re using federal funds, you have to build to current state-of-the-art codes.”
The International Building Code Foundation’s Paul Myers commented, “We’ve analyzed the last season’s hurricanes in Florida, and, yes, structures with contemporary codes, both homes and commercial buildings, did withstand the storms far better than older structures. I’m sure that those hurricanes got everyone’s attention and additional work on codes was done. Now, the last meeting of the current code cycle [for new codes in 2006] will be Sept. 25 through Oct. 1 in Detroit, MI. They will finalize the next addition to the building code then and flood-proofing and high wind protection will be embedded in separate sections.”
Asked for lessons from Hurricane Katrina, Myers replied, “Disasters can certainly strike at a moment’s notice and we all need to be prepared. The way to be prepared is to build structures as strongly and faithfully as we possibly can. It’s always an economic fight to determine how you will spend your money. Spending it on something, which might happen is sometimes difficult, but eventually most owners, contractors and architects see the light and they will build stronger, safer communities.
“The people who do this kind of work are silent defenders of our nation. The fact is, with hurricane-resistant, seismic resistant, and even terrorist-resistant buildings, someone has to look out for the American public, and that’s our job.”
(Information on where ICC codes are being used is available on www.iccsafe.org). CEG