Senate hearing focuses on repairing levees in New Orleans

Nov 18, 2005

It is clear that there were multiple causes for the levee failures in New Orleans, but researchers need to gather more data to better understand what they were and how to rebuild properly after the devastation caused by Hurricane Katrina, according to testimony today before the U.S. Senate Committee on Environment and Public Works. Tom Zimmie, professor and acting chair of civil and environmental engineering at Rensselaer Polytechnic Institute, offered his perspective on the degree to which the preliminary findings on the failure of the Gulf Coast levees are being incorporated into the restoration of hurricane protection.

"There is not one simple answer as to why the levees failed," Zimmie said in a prepared statement. "Field observations indicated various causes: overtopping of the levees, erosion, failure in foundation soils underlying the levees, seepage through the soils under the levees causing piping failures, and this is not a complete list."

Zimmie spent a week in New Orleans as part of an expert team investigating levee failures in the aftermath of Hurricane Katrina. The team, which was funded by a special exploratory grant from the National Science Foundation, released their preliminary report Nov. 2 in a presentation to the Senate Committee on Homeland Security and Governmental Affairs.

Others at today's Environment and Public Works hearing echoed Zimmie's comments, noting that until all the physical evidence has been collected and analyzed, engineers will not have a complete picture of what happened.

"Hopefully the results of our study will lead to a clear appreciation of what happened in Katrina, and that the lessons learned from this event will lead to improved protection in the future, not just in the New Orleans area, but throughout the nation and around the world," Zimmie told the committee. "The emphasis today is New Orleans, but we really have thousands of miles of levees in the United States."

Regarding the preliminary report, questions from the committee focused on the peat layer found under some levee sections in New Orleans. It has been suggested that a soft, spongy layer of swamp peat underneath the 17th Street Canal floodwall caused this wall to breach, and that this same peat layer runs under other levee sections. Zimmie noted that it is too soon to draw final conclusions about the nature of the peat layer and its implications for the levee failures.

"How widespread is it? We can't really answer that question at this point," Zimmie responded. "That's a big concern. The other parts of the levee system haven't been tested. It's like a chain; you have one weak link in the chain and the whole chain has failed. So now you have another link further down. You fix one link and then the next link fails."

"Peat is very common in the New Orleans area. I don't think there's any question about that. . . . It's a swampy area, so of course there's peat," Zimmie continued. "So the question is, how much soil sampling do you do? I don't think we know the answer at this point in the game. . . . I think with the investigation -- securing soil samples, getting more information to do a proper design -- then we should be able to answer that."

Zimmie was joined at the hearing by several other panelists: Dan Hitchings, director of Task Force HOPE for the U.S. Army Corps of Engineers; Sherwood Gagliano, president of Coastal Environments, Inc.; Larry Roth, deputy executive director of the American Society of Civil Engineers; Joseph Suhayda, emeritus professor of engineering at Louisiana State University; and Robert Verchick, a professor at Loyola University Law School in New Orleans.

Sen. James Inhofe (R-Okla.) is chair of the Committee on Environment and Public Works, and Sen. James Jeffords (I-Vt.) is the ranking minority. Other committee members in attendance were Sen. David Vitter (R-La.), Sen. Christopher Bond (R-Mo.), Sen. John Thune (R-S.D.), Sen. Johnny Isakson (R-Ga.), and Sen. Thomas Carper (D-Del.).

Source: Rensselaer Polytechnic Institute

Explore further: Evidence for supernovas near Earth

add to favorites email to friend print save as pdf

Related Stories

Dinosaur footprints set for public display in Utah

3 hours ago

A dry wash full of 112-million-year-old dinosaur tracks that include an ankylosaurus, dromaeosaurus and a menacing ancestor of the Tyrannosaurus rex, is set to open to the public this fall in Utah.

Fitbit to Schumer: We don't sell personal data

3 hours ago

The maker of a popular line of wearable fitness-tracking devices says it has never sold personal data to advertisers, contrary to concerns raised by U.S. Sen. Charles Schumer.

Dead floppy drive: Kenya recycles global e-waste

3 hours ago

In an industrial area outside Kenya's capital city, workers in hard hats and white masks take shiny new power drills to computer parts. This assembly line is not assembling, though. It is dismantling some ...

Tissue regeneration using anti-inflammatory nanomolecules

4 hours ago

Anyone who has suffered an injury can probably remember the after-effects, including pain, swelling or redness. These are signs that the body is fighting back against the injury. When tissue in the body is damaged, biological ...

Recommended for you

Evidence for supernovas near Earth

25 minutes ago

Once every 50 years, more or less, a massive star explodes somewhere in the Milky Way. The resulting blast is terrifyingly powerful, pumping out more energy in a split second than the sun emits in a million ...

Local model better describes lunar gravity

2 hours ago

Two satellites orbiting the Moon as a part of NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission have been mapping its inner structure by measuring subtle shifts in the pull of gravity on the ...

What lit up the universe?

7 hours ago

New research from UCL shows we will soon uncover the origin of the ultraviolet light that bathes the cosmos, helping scientists understand how galaxies were built.

Eta Carinae: Our Neighboring Superstars

15 hours ago

(Phys.org) —The Eta Carinae star system does not lack for superlatives. Not only does it contain one of the biggest and brightest stars in our galaxy, weighing at least 90 times the mass of the Sun, it ...

User comments : 0