New Orleans Worst Case?

[yowzayowzayowza]

I keep encountering the worst case from Katrina being New Orleans flooded for months, but I'm thinkin it could be a whole lot worse. If the levy breaks AND the Mississippi River flow gravitates to the deeper area, downtown New Orleans, pumping out the water may be the least of the problem. The Army Corps might have to deal with re-constraining the river banks before they can even begin to pump out the city.

Have I mist sumthin? Anyone encountered a discussion of this possibility?

[Maple]

1. I saw something awhile ago

calling it 'Atlantis'

I'd say that was the worse case scenario.

[Endangered Specie]

2. two things... 1) It is highly unlikely that the levee would break

2) in the absolute worst case... they might wish it WOULD BREAK, because if it completely floods over, the levee will act to HOLD WATER IN new orleans (levees work both ways).

[expatriot]

6. whether the sea will rise above the levee is NOT in question...

What is in question is HOW MANY multi-level buildings within the city will collapse due to the surge.

[Endangered Specie]

9. That and the winds wont help either.

The tallest buildings are more in danger due to winds (remeber, the winds are worse the higher up you go) rather than floods which will get the low to med rise buildings.

[earthside]

11. Why?

Why is it highly unlikely that the levee would break?

Of what are they constructed?

[Endangered Specie]

13. Well this may not sound scientific but...

There has been pretty much no discussion of levees breaking, the main worry is levees not being high enough. AFAIK they are basically huge mounds of earth with some artifical materials thrown in.

[yowzayowzayowza]

24. Disagree.

In this scenario the storm surge allows the river to flow OVER the levy for sufficient time to undercut it from behind weakening it sufficiently to leave the river flowing thru downtown after the storm surge.

[swag]

3. A Scientific American article from around 4 years ago posits your case

Title: Drowning New Orleans.
Authors: Fischetti, Mark
Source: Scientific American; Oct2001, Vol. 285 Issue 4, p76, 10p,

(via shamus and ogre at omni_bb - a linux shell bulletin board).

There's also this:

http://americanradioworks.publicradio.org/features/wetlands/hurricane_print.html

Do you expect this kind of hurricane—this kind of flooding—will hit New Orleans in our lifetime?

"Well I would say the probability is yes," says Suyahada. "In terms of past experience, we've had three storms that were near misses—that could have done at least something close to this."

Basically, the part of New Orleans that most Americans—most people around the world—think is New Orleans, would disappear.

Suyhayda agrees, "It would, that's right."

[yowzayowzayowza]

8. Didn't see a discussion in that article...

of the river bed running directly thru the city.

Anywaze, this could get really ugly really quick.

[swag]

10. Well, like most folks, I hope it doesn't.

But the hurricane is bearing down.

[Spinzonner]

4. Well, they could add an earthquake on the New Madrid fault

:-(

[kbm8795]

31. Nooooooooo!!!

I live near that faultline. . .

[Chichiri]

5. Worst case: New Orleans will cease to exist.

Except maybe for archaeologists and scuba divers.

[chookie]

7. Hail, Atlantis

This storm may also change the course of the Mississippi River, which is on a very unstable delta.

Barring a miracle -- and I hate to say this -- the scenario you envision is likely. We're all going to be grieving soon....

[yowzayowzayowza]

12. Other than being a bit bigger...

the only thing I can think of that could be worse is if Katrina were headed directly at NO from the SE rather than due S, thus driving a storm surge along the coast line and focusing the wave in the NO area.

[Silverhair]

19. I saw a Cray computer model of that in the mid'80s.

It was called a "Project Storm" and is the very worst case scenario. The wave does get focused and the winds push the lake into New Orleans.

[TahitiNut]

14. Katrina is going to give the French Quarter a blow-job. Ironic.

Why couldn't the GOP be having a convention there -- with an airline strike? :evilgrin:

[lonestarnot]

21. Yeah, probably had my last praline from there!

[TahitiNut]

29. No more Hurricanes at Pat O'Brien's, either.

No more brunches at the Court of the Three Sisters. (sigh)

[Zhade]

39. Court of the Three Sisters!

How I remember it...

I'm very afraid for those who can't afford to leave. Too bad I don't believe in any gods to which I could supplicate.

[havocmom]

30. you bad

and dats why we loves ya

[applegrove]

15. The city floods and to kill off the pestulance the Navy blasts holes in

the remaining sea wall to allow clean sea-water to rush in. Gasoline and chemicals leach into the Gulf of Mexico.

Whatever happens ... solong as as few people as possible die..that is the most important thing.

[wli]

16. Francis Bacon had something else in mind in "The New Atlantis." n/t

[Sgent]

17. The levy breaking

if the storm surges over it isn't a problem -- that's why no one's talking about it.

In fact, during Betsy -- the last major hurricane, they actually planted dynamite along the levy's and blew them up so they could drain most of the water. They have locks now so hopefully they can avoid that.

[applegrove]

18. Do the lochs work when they are under 20 feet of water? I hope so.

also the water will not drain out if NO is under sea level. They will have to go much lower in the levy to drain. Anyway - as long as there isn't an epidemic of illness - heard somewhere that they bury the dead above ground in new orleans because of the sea-level problem. Those people have not been evacuated. What happens to those bodies? I hope they were all cremated.

[Endangered Specie]

25. good question...

I doubt they will, unless they got some very fancy mechanical system.

Yes, everyone is buried above sea level in coffins... its quite a sight. In fact theres usually one coffin for each family, you essentially DO get creamated in these things. After a year of being exposed to new orleans heat in an air tight concrete coffin it might as well be an oven. Cause, after a year or so, the only thing left is bones, and when the time comes they will reopen it, stuff the remains into the back, and put the next family member in, and repeat the process. So in a way, the whole family will all be with each other again posthomously.

As far as blowing the levees, yes they are below sea level but with the levee open it will at least drain the water that the levee is directly holding in above sea level!

[applegrove]

32. So - would they blow them up - going lower to get sea water to mix in with

the pestulance filled bathtup? To count on the tide to take some of it out? Sewer water..deat critters..rotten stuff..chemicals..what a horid soup. Worst case scenario. Would they do that?

[Endangered Specie]

33. I dont think many of them have thought about what they would do

who would make such a decision anyway? I mean worst case it becomes a gigantic pool of toxic poison (toxic gumbo, as I heard on the tv) you cant just release that, but at the same time you cant just let it stay there. Damned either way.

[zulchzulu]

20. There's "worst case" and then "Worst Case"

Eventually with the way global warming is continuing, New Orleans will be like Venive, Italy in 30 years.

This storm may jumpstart the eventuality.

The levees will be able to get rid of all the main water damage in a couple of days, but the damage will be great.

Fortunately, many buildings in the Quarter are over 200 years old and will survive. It's the ones in other parts of the city like the Garden District that will be horribly damaged.

I may make a trip down there to help out, being that I lived there and find it one of the most amazing cities in the US.

[Emperor_Norton_II]

23. New Orleans hasn't been hit by a storm like this *ever*

It doesn't matter that the Quarter's 200 years old, the buildings there were not intended to stand up against 170mph winds and a storm surge that will completely immerse most of the damn city. NOLA officials are expecting that the pumps will take weeks, not days to clear the basin. Assuming they're still capable of functioning, that is.

[orleans]

22. bushie was against "nation building" and look at iraq

how does the prick feel about "city building" when it comes to this type of emergency?

that s.o.b. has a guilty conscience after cutting the f.e.m.a. program that worked to help places withstand disasters --and the fact that LA didn't get any funding for it in 2004 or 2003 even though it was dubbed the floodplain of the nation. did they get some funding in 2005? i guess they will now, huh?

damn--i'm just sick about this --so worried for those people down there.

[swag]

26. One more "worst case" article that doesn't include your river

http://www.colorado.edu/hazards/o/nov04/nov04c.html

The Aftermath
In this hypothetical storm scenario, it is estimated that it would take nine weeks to pump the water out of the city, and only then could assessments begin to determine what buildings were habitable or salvageable. Sewer, water, and the extensive forced drainage pumping systems would be damaged. National authorities would be scrambling to build tent cities to house the hundreds of thousands of refugees unable to return to their homes and without other relocation options. In the aftermath of such a disaster, New Orleans would be dramatically different, and likely extremely diminished, from what it is today. Unlike the posthurricane development surges that have occurred in coastal beach communities, the cost of rebuilding the city of New Orleans’ dramatically damaged infrastructure would reduce the likelihood of a similar economic recovery. And, the unique culture of this American original that contributed jazz and so much more to the American culture would be lost.

Accepting the Reality
Should this disaster become a reality, it would undoubtedly be one of the greatest disasters, if not the greatest, to hit the United States, with estimated costs exceeding 100 billion dollars. According to the American Red Cross, such an event could be even more devastating than a major earthquake in California. Survivors would have to endure conditions never before experienced in a North American disaster.

Loss of the coastal marshes that dampened earlier storm surges puts the city at increasing risk to hurricanes. Eighty years of substantial river leveeing has prevented spring flood deposition of new layers of sediment into the marshes, and a similarly lengthy period of marsh excavation activities related to oil and gas exploration and transportation canals for the petrochemical industry have threatened marsh integrity. Sea level rise is expected to further accelerate the loss of these valuable coastal wetlands, the loss of which jeopardizes the fabric of Louisiana communities by threatening the harvesting of natural resources, an integral part of coastal culture. Concerted efforts by state and federal agencies are underway to develop appropriate restoration technologies and adequate funding to implement them.

. . .

[Lenore]

27. 25,000 to 100,000 dead...

Per Civil Engineering Magazine's article that references a Red Cross study on this very scenario.

::snip::
In the 1990s, Suhayda began modeling category 4 and 5 storms hitting New Orleans from a variety of directions. His results were frightening enough that he shared them with emergency preparedness officials throughout Louisiana. If such a severe storm were to hit the city from the southwest, for instance, Suhayda’s data indicate that the water level of Lake Pontchartrain would rise by as much as 12 ft (3.7 m). As the storm’s counterclockwise winds battered the levees on the northern shore of the city, the water would easily top the embankments and fill the streets to a depth of 25 ft (7.6 m) or more.

Suhayda’s model is not the only one that describes such a catastrophe. A model called SLOSH (Sea, Lake, and Overland Surges from Hurricanes), which is used by the National Weather Service and local agencies concerned with emergency preparedness, portrays an equally grim outcome should a storm of category 5 hit New Orleans. The SLOSH model does not contain nearly as many computational nodes as does AdCirc, it does not use a finite-element grid to increase the resolution of the nodes on shore, and its boundary is much smaller. Even so, its results are disheartening.

“Suppose it’s wrong,” says Combe, the Corps modeler. “Suppose twenty-five feet is only fifteen feet. Fifteen feet still floods the whole city up to the height of the levees.”

Experts say a flood of this magnitude would probably shut down the city’s power plants and water and sewage treatment plants and might even take out its drainage system. The workhorse pumps would be clogged with debris, and the levees would suddenly be working to keep water in the city. Survivors of the storm—humans and animals alike—would be sharing space on the crests of levees until the Corps could dynamite holes in the structures to drain the area. In such a scenario, the American Red Cross estimates that between 25,000 and 100,000 people would die. (bold mine)
::end snip::

http://www.pubs.asce.org/ceonline/ceonline03/0603feat.html <~~indepth article detailing potential scenarios, one of which NO is now facing.

The article also discusses how the levees will retain water until they are blasted open....

[yowzayowzayowza]

34. Good article, but...

still does not discuss potential river flow changes caused by a storm surge.

Thx.

[Endangered Specie]

35. Apparently, when the last major hurricane came close to NO

it caused the Mississippi to flow in the WRONG direction in the NO area. That was quite a freaky sight I bet.

[yowzayowzayowza]

40. Makes sense; question is:

What if it doesn't fill the same riverbed when it turns 'round?

...time fer some zeds. Hope all goes well!!!!

[FloridaPat]

28. When the Mississippi overflowed a few years back near St. Louis

the levees broke. And yes, they did make it worse.

[Solon]

37. I remember that, the "Great Flood of '93"

is what it is called around here. Luckily, my parents lived near the top of a big hill just outside of St. Charles Missouri City limits, however, much of our country was completely flooded when the levees broke, many people lost their farms and homes in that flood, along with quite a few lives. Here's some pictures from my area during the flood.

Train Station, near Missouri riverfront, St. Charles:


Here's a better graphic, satellite image of my county and St. Louis country, before and after pictures.


Incase you wondered, St. Charles County is the one in between the rivers in the map, the county that is damn near gone in the picture. If you see the second picture, our house is located about one quarter a mile south of that deep dip in the flood plain in the western portion.

[FloridaPat]

41. Thanks for the pictures. It was amazing to see a river that wide on TV.

Hope you never see that again.

[tedoll78]

36. I thought it was supposed to turn by now??!?

The forecasters kept on going on and on about how it was going to turn to the northeast.. and yet Katrina's keeping that western element to her northerly movement. This is only going to make things worse.

[politicat]

38. The worst case depends on the oil industry in the area....

Between 30% and 40% of the imported oil in the US comes through the 3 NOLA ports. If those ports are closed or damaged, that oil will have to be rerouted, and there are only about 30 US ports that can handle crude tankers... and most of them can only handle a crude tanker a week, instead of 2 a day like NOLA-region. Further, most of those are on the East and West coasts, not on the Gulf Coast, meaning that the midwest is going to be in a lot of trouble.

If the NOLA port is closed, then most of our grain and ag products exports cease. We've shipped nearly everything from the midwest down the Mississippi, and if we have to truck or train that grain overland, the cost to ship it becomes prohibitively high. Since much of our ag exports are not to developed countries, our former buyers are likely look for other, cheaper suppliers.

About 30% of the US oil refinery capability is in and around the Mississippi Delta. If that is damaged, we've lost for at least a year a third of our oil refinery industry. We will probably have to ration gas; it may not be available for sale for under $6 a gallon in parts of the country. The industry may not recover. (I can hope.)

As Katrina moves inland, it will damage those same crops - you can't harvest wet grain or soybeans, and it's harvest time now. Further, you can't wait for them to dry out; the material deteriorates. So this year's grain and soy crop is probably at least 10% shot.

The worst case scenario is that every one in the nation and a lot of people around the world end up, if not starving, then hurting badly.