Kudos to Derek Ortt and Daniel Stern for recognizing Katrina

[Margie]

Margi, the article on the 17th street levee is wrong. The sheet pilings were the correct depth when a few were pulled out.

A team of well-respected experts has proven otherwise. What are you basing your statement on?

[Tri-State_1925]

I thought from initial reports that this was already being called a 3 at landfall. Oh well...now it's offically a 3. No surprise.

[wxman57]

I wonder what the author considers a "slow-moving" storm? Katrina was moving at around 16 kts at landfall and accelerating. That's definitely NOT slow-moving, and it's one reason that it carried the strong winds well inland into northern MS.

[wxman57]

Margi, the article on the 17th street levee is wrong. The sheet pilings were the correct depth when a few were pulled out.

A team of well-respected experts has proven otherwise. What are you basing your statement on?

Margie, I saw the news report on the pilings as well. It looked like they may have been too short using sonar, but when the pilings were actually pulled out they were the correct 17ft depth.

[Pearl River]

From the New Orleans Times-Picayune

The measurements taken Tuesday support the corps' long-standing contention that the sheet pilings supporting the floodwall were driven to 17.5 feet below sea level, and cast doubt on seismic testing done by the corps and an investigative team working for the state that indicated the pilings were driven only to 10 feet below sea level.

What they are looking at now is the problem may have been that the canal was dredged too deep.

[terstorm1012]

Are they planning on closing off the Gulf Outlet?


Oh--------good work to Derek and his fellow collegue....you stuck by your story even when most of us were like "you're crazy, dude."

[Pearl River]

They are playing around with the idae of closing it, but I don't think they have made that decision as of yet.

[Pearl River]

Derek, you were right. My apologies to you sir.

[terstorm1012]

That Katrina report was still sad to read ... 4,000 still missing? oh my goodness...

[Pearl River]

terstorm1012 said

That Katrina report was still sad to read ... 4,000 still missing? oh my goodness...

Whats even sadder. Alot of those missing are children.

[terstorm1012]

terstorm1012 said

That Katrina report was still sad to read ... 4,000 still missing? oh my goodness...

Whats even sadder. Alot of those missing are children.

That is truely heartbreaking!

[Jam151]

I depends on who you believe.....Ivor van Heerden was the one all emergency management planners laughed when he made suggestions for "Big One" planning.

LSU expert defends piling tests
Corps' findings no absolution, he says

http://www.nola.com/printer/printer.ssf ... 141790.xml

[Zackiedawg]

what this tells us is... actually design the levees to withstand a category 3 hurricane, and the region will be many times safer. We had levees that failed in cat 1 conditions

Question: How long would it take for the storm surge 'bulge', along with wind-formed waves, to recede after the hurricane drops its winds to a lower category?

I've wondered if there is any accurate way to estimate this, as a storm like Katrina brings the problems to light. Katrina was at one point a strong Cat 5 storm, and during much of her approach to land was still a strong Cat 4 storm. So over the several days that she churned through the gulf at Cat 5 or 4, and considering the large size of the storm's hurricane windfield, she built up a high cat 4 to cat 5 storm surge.

So if hours before landfall, the hurricane's winds were measured at Cat 3 strength, meaning she downgraded just before hitting land, would it not take much more time for the seas ahead of her to 'calm' to a level more appropriate to a smaller storm?

It seems like Katrina downgraded her windspeed before striking land, but her surge was still at Cat 4 level or more as it pushed up on shore. Combined with the shallow ramp up on the gulf coast and the high tide, the surge seemed to be equal to a Cat 4 or 5 storm.

And though New Orleans experienced no more than Cat 1 winds, wouldn't they too have been fecing the effects of a far stronger surge? A ripple travelling across a pond does not greatly diminish in height as it travels...the degredation of strength, speed and height is much slower in water than in air. So despite Katrina's Cat 3 deintensification, it would seem logical to conclude that much of the Mississippi coast received high cat 4 or cat 5 surge, and New Orleans' lakes and canals were bulged by surge of at least Cat 3.

Any opinion?

[f5]

Katrina was odd,very odd her winds might have been weaker but guess what she kick Camille's butt as far as storm surge go.she took alway Andrew's pride as far as being the costliest

[MGC]

The water in the 17th street canal reached 14 feet. The levees failed around 11 feet. Since when is 14 feet a Cat-1 surge?....MGC

[Derek Ortt]

for a shallow place like Lake Ponchartrain, that is not unreasonable. Apalachee Bay had 10 feet from tropical storm conditions with Dennis

it matters not what the intensity is in the open ocean... there is no open ocean surge, except that due to the abrometric pressure. The surge does not pile up until the hurricane moves onto the shelf. What remains though are the waves generated while at sea

[Pearl River]

Lake Pontchartrain is indeed a shallow lake abt 12-14 ft deep, deeper in some dredged areas. A strong east wind for a couple of days, depending on tidal height, will raise the lake a couple of feet. Even though the pilings in the 17th street canal were at 17.5 ft, some areas of the canal were dredged to 18.5 ft. The thinking now is the water undermined the pilings.

[HurricaneBill]

Lake Pontchartrain is indeed a shallow lake abt 12-14 ft deep, deeper in some dredged areas. A strong east wind for a couple of days, depending on tidal height, will raise the lake a couple of feet. Even though the pilings in the 17th street canal were at 17.5 ft, some areas of the canal were dredged to 18.5 ft. The thinking now is the water undermined the pilings.

Wow, considering how large it is, that seems like a very shallow lake.

Same with Lake Okeechobee. That lake is only about 20 feet deep.

[HurricaneBill]

Here you go, Derek!

[Stormcenter]

when a cat 4 or 5 hits land, it means that total destruction can be caused by wind alone,. Charley produced less surge than TS Gabrielle did, its winds were powerful enough to devastate everything

I want anyone who still lives in New orleans or is planning to go back to know this. The city did NOT experience a major hurricane. Please do not be lulled asleep into thinking katrina was as bad as it gets. if a 4 moves into the city, vertical evacuation is not possible as the winds will destroy anything above the surge

I think everyone along the LA, MS, & AL got the message this time around. By the way I don't believe ANYONE in along the LA. & MS. believes it can get any worse when they've lost EVERYTHING due to Katrina's flood causing storm surge. Derek how can you tell these folks it can get any worse? It just can't. I've seen it first hand. They don't have anything. To them it can't any worse than what Katrina did. In "their" eyes Katrina was and always be as bad as it can get.