levees

New levees plan won't protect SBP, Lower Ninth, N.O. East

The Army Corps of Engineers said the plan for improved levees that is being pushed by President George Bush is a good one for the areas where levees breached but will do nothing to protect the Lower Ninth Ward, New Orleans East or St. Bernard Parish.
...The plan calls for closing off the levees at the London Avenue, Orleans Avenue and 17th Street Canals by June 1, 2006...
In addition the levees will be built over with concrete and pumping stations would be positioned near Lake Pontchartrain within two years.
The plans are based on the standard of a true Category-3 and Congress used 100 miles per hour winds as their gauge for satisfactory flood protection in the short term.
The Corps has also been given two years to come up with a proposal for Category-5 protection...

source

Floodwalls seem to have been built to ACE specifications

Was the floodwall failure at the 17th Street Canal due to bad design by the Army Corps of Engineers, or bad construction by contractors?
They pulled eight sections of the steel sheets that were driven into the ground, and so far that seems to indicate that they were installed to the designated depth: "Engineers Reverse New Orleans Levee Finding".

...The steel had been sunk into the ground to prevent water from saturating the soil and destabilizing the flood walls. Initial testing by sonar had indicated the sheet pilings were driven to only about 10 feet below sea level, even though the design called for 17.5 feet below sea level...
...Brig. Gen. Robert Crear said the length of the sections pulled all exceeded 23 feet. About six feet of the sheet piling was above sea level, leaving a little more than 17 feet below sea level - in accordance with design specifications.
Engineers also plan to test the concrete and the reinforcing bars in the flood wall to ensure they were made properly.
Also, engineers must try to figure out why the sonar tests yielded bad results on how deep the sheet pilings were driven.

Brian Williams interviews George Bush

NBC's Brian Williams conducted a long interview with president Bush, and the section about Katrina has Bush:
- repeating his blame-taking for the weak federal response ("to the extent that the federal government was ineffective, I'm responsible")
- given the opportunity to blame Blanco, Nagin, or others, he said "we're beyond that"
- he was watching the TV reports from the Superdome...
- he "certainly hopes" that we won't lose New Orleans on his watch...
- Bush not only knows what the Ninth Ward is, he's familiar with the conspiracy theory about the government blowing up the levees...
- Bush has read about- or had someone tell him about - the blowing up of the levees that occured in the 20s...
And, there's this perhaps-not-entirely-accurate bit:

one of the things we've learned about the levees, Brian, is that they call the levees a certain category, but they weren't up to standards. And so we're now in the process of working with local folks to get the standards of the levees up to where they should have been prior to the storm and even better. And hopefully we'll have the capacity to announce that relatively quickly.

The levees and floodwalls might not have been designed correctly however.
Also:

I remember saying that, when I thanked those chopper drivers from the Coast Guard who performed brilliantly, they didn't lower those booms to pick up people saying, "What color skin do you have?" They said, "A fellow American's in jeopardy. And I'm going to do my best to rescue that person."

However, some far-lefties have speculated that shots fired at choppers were because they were being ignored because of triage.
Speaking about Brownie:

You know, Michael [Brown], resigned. And I, you know, I had worked with him during the four hurricanes that hit Florida. He got pretty good marks. And in this case, for whatever reason, the system overwhelmed the whole process. And Michael said, "I'm responsible." And he left.

Katrina, the "man-made disaster"

NOLA has a round-up of the latest evidence pointing to the flooding being caused not by the hurricane so much as "operator error": incorrect design decisions by the Army Corps of Engineers and others. Commentary here. Keep us informed if we ever learn who's right.

"Dredging could have contributed to levee failure"

From this:

When the New Orleans Sewerage and Water Board developed a plan in 1981 to improve street drainage by dredging the 17th Street canal to increase capacity for Pump Station No.¤6, residents across the city applauded. Increasingly heavy rains were not only flooding streets, but pushing water into homes. Action was needed. It seemed like a no-brainer.
Today forensic engineers investigating the levee breach that flooded much of city during Hurricane Katrina aren't so sure. The search for the cause of the failure keeps returning to that dredging project as the probable starting point for a series of mistakes they believe ultimately led to the breach...
Before the project, the canal formed a roughly symmetrical "U" shape common to most canals. In the sections that would later fail during Hurricane Katrina, its average depth was about 12 feet below sea level and, at normal water levels, the Orleans side had about a 20-foot buffer of mud between the water and what was then a bare steel flood wall. That wall of sheet piling ran through the center of the levee to a depth 9.8 feet below sea level.
After the dredging, the bottom was 18.5 feet below sea level, and the canal-side levee had been shaved so narrow, water now touched the wall on the Orleans side. The "U" was now lop-sided and the water in the canal had shorter paths to the outside of the levee.
A review of records maintained by the two levee districts hasn't yet revealed why more extensive dredging was done on the Orleans side of the canal than on the Jefferson side.
"I've never seen a canal profile unbalanced like that, and I can't account for why it was done that way," said Bob Bea, a University of California-Berkeley professor and member of the Science Foundation team...

Levee breach, flooding timeline: who knew what when?

Monday 8/29, early morning: hurricane strikes
Monday 8/29, later that morning: Fox might have broadcast news of the break(s)
Monday 8/29, early afternoon: breaches reported to NO authorities [1]
Monday 8/29, 6pm : confirmed in a summary distributed by the Louisiana Office of Homeland Security and Emergency Preparedness [1]
Monday 8/29, "later in the day" : Blanco finds out [1]
Tuesday 8/30, midnight to 1am: CNN broadcasts a live report on the breach(s) [2]
Tuesday 8/30, late morning: DHS head Michael Chertoff finds out about the issue [1]
[2]: two blog reports: here and here
[1]: "News of levee breach hit D.C. late":

Federal and state emergency officials knew by early evening on the day that Hurricane Katrina made landfall that New Orleans' levees had ruptured and that much of the city was inundated with water, documents turned over to congressional investigators by Gov. Kathleen Blanco's administration show.
But that critical information did not make it up the chain of command to the U.S. Department of Homeland Security until more than 15 hours later, a delay that some Louisiana officials believe compromised the effort to rescue people stranded by floodwaters.
The breach of the 17th Street Canal levee, which was reported to New Orleans authorities early on the afternoon of Aug. 29, was confirmed by the Louisiana Office of Homeland Security and Emergency Preparedness in a 6 p.m. summary distributed to state and federal emergency officials in Baton Rouge.
"No power, 911 system down, EOC (emergency operations center) on emergency power and cell phones," the summary said. "Entire city flooded, except French Quarter/West Bank/Business district."
Farther down, in bold type, the summary report notes three breaches in the New Orleans area, including the 17th Street Canal...
FEMA Director Michael Brown, who was in Baton Rouge that day, would have had access to the summary, as did other state and federal officials.
Mark Smith, a spokesman for the state Office of Homeland Security and Emergency Preparedness, said it would have been clear to anyone who had read the summary what was happening in New Orleans. "Her (Blanco's) staff and our staff and the FEMA staff on site . . . all know the implications of any levee in Louisiana going down," Smith said.
But Homeland Security Secretary Michael Chertoff did not find out about the flooding until late Tuesday morning. Russ Knocke, a spokesman for Chertoff, said he doesn't know why the information wasn't conveyed sooner.
"I can't speak for Michael Brown. I can't tell you what happened with that information when . . . it was presented to Mike," Knocke said. "I can just tell you that from our part in Washington, D.C. . . . it was an extraordinarily frustrating period because we simply lacked visibility. That was a result of inadequate information from the field."
Knocke declined to speculate on whether the federal response would have been quicker had Chertoff understood the gravity of the situation sooner. "That's like asking someone to go back and play armchair quarterback," he said...

New Orleans flooding caused by Army Corps of Engineers' bad design?

"Team Louisiana", the state-sponsored "forensic levee investigation team" with "six LSU professors and three independent engineers" says the floodwall on the 17th street canal was bound to fail due to improper design that didn't take into account weak soils below the levee.
And, they say that bad design should have been obvious to those responsible: the Army Corps of Engineers, Eustis Engineering (a local company) and Modjeski and Masters (national company).

That miscalculation was so obvious and fundamental, investigators said, they "could not fathom" how the design team of engineers from the corps, could have missed what is being termed the costliest engineering mistake in American history.
..."It's simply beyond me," said Billy Prochaska, a consulting engineer in the forensic group known as . "This wasn't a complicated problem. This is something the corps, Eustis, and Modjeski and Masters do all the time. Yet everyone missed it -- everyone from the local offices all the way up to Washington."

Reaction here and here.
Previously: "Floodwalls in Swampy New Orleans 'Like Putting Bricks on Jell-O'"

"New Orleans Levee Break(s) Before and After"

This 8/30 post has several pictures and maps showing the breaks. She also has a category with several other posts. (nofollowpolicy in effect).

Floodwall pilings seven feet shorter than Army Corps of Engineers said

From this:

Sheet piling supporting the failed floodwall on the 17th Street Canal extends just 10 feet below sea level, 7 feet shorter than the Corps of Engineers has maintained, a team of investigators said Wednesday [11/9], strengthening earlier findings that faulty design and construction played a role in the canal breaches that flooded much of New Orleans during Hurricane Katrina.
An LSU forensic engineering team, working in conjunction with the state attorney general's office, began examining the levee foundation with ground sonar Wednesday. The first reading was taken about 150 yards south of the break that allowed water from Lake Pontchartrain to inundate the city.
Independent engineers have questioned whether the pilings, even at the corps' stated depth, went down far enough to support the floodwalls and prevent storm surge from penetrating beneath the earthen levees and causing structural failure...

"Floodwalls in Swampy New Orleans 'Like Putting Bricks on Jell-O'"

From this:

When the Texas construction firm AquaTerra Contracting began work on an Army Corps of Engineers hurricane protection project on New Orleans' West Bank, it encountered a serious problem: Its floodwalls wouldn't stand up straight in the mushy soil.
AquaTerra workers tried driving steel sheet piling down to the 55-foot depth the design required for the walls' foundation, company CEO Clay Zollars said. But the piling began to lean inward.
Zollars said the corps decided to nearly double the depth of the steel foundation to 105 feet. That didn't work either.
"Before we completed the wall, it began to lean and sink also," Zollars said. "The pilings were inadequate. The corps corrected that by installing some additional reinforcing steel in the concrete, but the wall still is leaning."
The top of one section of the 10-foot wall is more than a foot off the vertical, he said. AquaTerra is seeking $5 million it says the corps owes it for the extra work on the $11.1 million contract. Corps officials won't comment on the case because of the dispute.
The problems illustrate one of the basic obstacles to building reliable levees -- or any heavy structure -- in south Louisiana: It's a swamp.

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