A question about the levee break

[Don Claybrook]

It's my understanding that the levee system protecting NO from Lake Ponchatrain has given in 2 places. I saw that they were going to try to drop 3000 pound sandbags in an attempt to stem the flow. A later report suggested the sandbags weren't working.

Question: will these breaks not result in the water level equalizing between the lake and the city? In other words, unless they can repair the breaks somehow, is New Orleans under water for the forseeable future, until it can be slowly pumped out over time?

[KyndCulture]

1. the water is rising 6 inches per hour. 80% covered now.

The lady on WDSU is saying exactly this, it will eventually equalize and the city will become the lake.

[phusion]

4. And how far below sea level is the city?

Is the lake at sea level? If so, considering 80% of the city is something like 12-15 feet below sea level there will be 12-15 feet of water in the city.

How are they going to pump that out?

[jean]

13. here's that info from wikipedia

[KamaAina]

2. And another question

Why did the 17th St. Canal levee breach hours after the storm passed (and we all thought we were mostly out of the woods)?! Was it not properly maintained?

[lvx35]

6. CNN gave the impression that it was the volume of water, not the storm

that broke it. So after the storm was gone, but the rain was still coming down, the water level reached its highest level yet. But I'm not totally sure either.

[Jersey Devil]

8. Retired head of Army Corps of Engineers explained this

He said the levees are designed to hold back water that quickly recedes, but when they stay wet for too long they get undermined and that is when they give out. In this case they were wet for a long time, plus there were currents that you usually don't see from just a rise in water levels due to simple rainfall.

[phusion]

11. Why have something like that?

Why have something prone to being "undermined" protecting an entire city instead of building a good, solid dam or something similar?

I just don't get it...

[Jersey Devil]

14. Well, he also said that NO and LA have been warned for years

that the levee system was inadequate and that it had to be modernized with sturdy structures that could withstand a cat 5 hurricane. He said the levees in place were designed for no more than a cat 3 and that everyone in govt knew that for years and years but said they could not afford the tremendous cost of upgrading.

I guess they will include that in the bill now, huh?

[Eagle_Eye]

26. No problem pissing away 200 billion on a war in Iraq though

[Eloriel]

17. Earth is ultimately undermine-able. Concrete too wears away in time

and is probably a LOT more expensive than earth. I frankly don't know of any levees anywhere that were built of concrete -- just not done, and I grew up in the St. Louis area where there are lots and lots of levees.

[NorCalDem]

25. Because what else are you going to do?

People, it was a huge storm! Let's not blame the concrete levee's for breaking down, all the water puts A LOT of force onto those barriers, and there is nothing that anybody can really do about it. Water can exert tremendous forces when there is are millions of gallons of it, and the levees broke down.

If there weren't thousands of stranded people in the city, it wouldn't be such a problem (other than the total destruction of NO). Unfortunately for us, yet again, mother nature has proven herself to be quite the powerful adversary!

[Ready4Change]

33. Ultimately, the problem is the city location, not the levies.

Anyone who built a capital structure in that location now has evidence of their foolishness.

Any one who builds, or re-builds, there now has no excuse.

If I were an insurance company I would provide no funds unless the plan was to rebuild in an above sea level location.

Then again, I'm sitting comfortably at home, watching this all happen on TV.

[Ready4Change]

27. It's cheap, and works for 90% of the problems.

Thats a very pleasing answer for penny pinching bureaucrats viewing the numbers in good times.

Odds are the people who made the initial choices are now long out of office and not available to take blame.

[liberalpragmatist]

42. Also, the loss of wetlands hurts a lot too

Huge tracts of wetlands have been cleared and they were a natural protectant, absorbing much of the impact of storms.

Over the past couple centuries, the wetlands are gone and so is much of the natural protection.

[Ready4Change]

22. Like sand in a sandcastle.

Its firm until it becomes water logged. Then it flows.

Works fine for short term water problems, has problems with long term water presence.

[lvx35]

3. That is my understanding, yes.

The other big news is a good portion of the pumping capacity is gone because as of last night, at least some pump(s) where broken. My impression is that if it were working it would still take a long time to basically pump the lake out of the city. This whole thing might even end up altering NO permanently.

[Don Claybrook]

7. This brings up a very interesting question

Would it be responsible/sane/wise to rebuild in this bowl area?

[lvx35]

10. Great question. I think the aswer is no.

Given this report:
http://www.sciencedaily.com/releases/2000/01/000121071306.htm
Which basically says that NO has been naturally sinking for years, plus raised ocean line due to global warming, I think the future is bleak, even if they do rebuild.

[Jersey Devil]

15. Good question - practical answer is no imo

The place ought to be leveled and the people relocated. No one should be living on beaches, barrier islands and swampland under sea level.

[markus]

29. Absolutely. Let's also evacuate California and the desert cities of the SW

We should also evacuate DC and New York, since they're just terrorist magenets.

In fact, DC is wll in the flood plain on reclaimed land. We should just close all the monuments and move the government.

It's your idea, so I'm sure you'll subscribe to a special surtax to pay for it.

Frankly, if the government decides not to rebuild New Orleans, I think Louisiana should decide to stop pumping oil and loading ships for you until you change your mind.

It will kinda suck paying $10 a gallon to go buy that $10 loaf of bread, but what do you care?

[Name removed]

35. Deleted message

Message removed by moderator. Click here to review the message board rules.

[markus]

39. And what, Sir, makes you so testy?

Are you watching your natal place destroyed in a slow motion disaster of epic proportions?

And what makes you so wise to decide what shall happen and what shall not.

If one of my analogies struck close to home, then, bullseye.

[Don Claybrook]

41. ...

No, I'm not watching my home be destroyed. And if you are, I'm very sorry for you. Nevertheless, this doesn't give you any right to start verbally attacking, such as you did.

Moreover, how in the fuck has your understanding of reading comprehension brought you to the conslusion that I think I'll decide what should or shouldn't happen. I asked an opinion question about the reoccupation of New Orleans. ASKED, get it, sport? I had a question in my mind and asked it. What is your particular problem with that question?

Good luck to you, but stop with the attack stuff.

[lvx35]

43. Its just money, all ideas aside.

The fact that DC is on a flood plain has nothing to do with the situation in NO. Its different because according to reports, (see link above) NO is slowly deteriorating, unlike DC. If it becomes increasingly costly to keep water out of NO as it sinks then eventually people won't do it, it just won't be profitable for those funding reconstruction for the city as it was.

I wouldn't worry about the future of NO though, I understand this is just a section...And it wouldn't be the first time a city has begun to sink, sections of Venice, Italy had a similar fate, but people didn't abandon it! Venice goes to show how resilient the spirit of a city can be against this sort of thing, and I think it will be no different in NO, even if it really is that bad.

[NorCalDem]

28. How are you going to pump

without electricity??

[proud patriot]

5. That is my understanding of the situtation

the pumps are old also . $70 million in NO
flood protection funds were cut . I think the may
have updated the pumps with those funds .

[El Supremo]

9. The pumps can only pump out 1" per hour.

When thay all are working. So how deep will the water be?

[Walt Starr]

12. Um, where the heck do you think they pump the water?

Lake Pontchartain, which is the lake the levees were protecting the city from.

so they can't start pumping the water with the circa 1913 pumps until the levee is fixed...

[LynzM]

16. I was going to post that

There's no point in pumping the water back into the same reservoir that's flooding into the city :(

[Walt Starr]

19. Yep, if FEMA was worth its salt, they'd be working on getting some

more modern pumps transported down so that WEHN they cna actually pump the city out, they aren't depedning on 1913 relics.

[markus]

21. Engineers travel from all over the world to study "those 1913 relics"

so they can reproduce them.

[Walt Starr]

34. Yes, they do

but they are nowhere near well enough equipped to handle the current situation.

[markus]

38. How well equipped was Manhatten for the Twin Towers?

How well equiped is Califonia for The Big One?

When the pumps start, they will move 1" of rain's worth of water an hour and 1/2" an hour thereafter until the water is gone. I can't imagine the city wouldn't be dry in a week once the water levels outside the level return to normal tidal levels and the pumps are back online.

The real catastrophe is, even if the levees are old and built only to a Cat 3/4 storm standard, is some dumb ass contractor probably undermined the levee when the new "hurricane proof" bridge was built at the site.

The very idea that you could build a "hurricane proof" brige on the south short of Lake Pontchartrain is a pretty clear indication of incipient idiocy. Or corruption.

Louisiana has it's fair share of both, and maybe a little more.

If I were the guy who built that bridge, I would plan on not coming back. There will be a few hundred thousand people he would not want to run into once they get that thought in their heads.

[MissB]

23. Truly vicious cycle

plus add in the potential for some flood waters from the Mississippi that normally get dumped into the Lake.

[Don Claybrook]

24. Point taken

I hadn't even considered that.

Thanks.

[ChairmanAgnostic]

18. there are always pumps working in NO

unless something catastrophic has occured. Like now. Some of the walls and pumps are 100 yrs old. They work fine to keep the water below the street level, but once there is a huge flood, they are unworkable. (Once the level of water is above the pumps, these styled pumps do not work.) bringing in huge replacement pumps big enough to deal with this lake of water has never been done on this scale.

Second problem. Foundation damage. Once the water has flooded out the inside of the retaining walls (the inside, dry part) there is erosion, structural damage and a great possibility of total failure. The levee systems are now weakened and potentially at risk of further collapse.

Third problem. The huge amount of water now in the city will become stagnant, disease ridden and swampy. Many of the structures will be weakened, even permanently damaged by water. I once read an estimate that if a NO levee broke, more than 65% of all residences would become unfit for humans and would have to be razed. You are talking about several hundred thousand people who have been forcibly displaced. Never to return. All belongings, books, paintings, furniture, keepsakes, valuables, every single thing - gone.

Fourth Problem
Economic disaster. most urban areas employ, feed and support the local population. That engine has been turned off here, probably for good. Multiply the adverse impact by a factor of 3. Add to that the total lack of tourism (their biggest money maker) and you get just a hint of how catastrophic this loss has been.

I suspect that in the decade that it takes them to rebuild, they will eventually decide to raise the level of the city above sea level. Chicago did that successfully. (about 10 feet from the original lake-swamp level) So have other urban centers.

The alternative to scrapping it, or raising the "ground" would be to allow the water in permanently and create and american Venice.

[madokie]

20. If its water as far as you can see in each direction

how will they be able to fix the levee. Without repairing the levee no way you could pump all the water out, looks to me like. Just wondering

[Don Claybrook]

30. Thanks for all the answers. Conclusion: MSM Failed Miserably

And they continue to do so.

This should be the front-page, 72 point, above-the-fold. New Orleans is slowly drowning and utterly uninhabitable for the forseeable future.

[spuddonna]

45. Absolutely...

I think the biggest problem is that big news outlets like CNN have become 'just anchors' who report AP wire stories. There are few real reporters out there, on the ground covering the story from CNN...

That's why the real info coming out continues to show up hours earlier at places like WWL and WDSU, or from the blogs...

[DistressedAmerican]

31. A Related Issue. the Pumps Just Put Water Back In The Lake.

According to the mayor, pumping right now does nothing but slow the total accumulating in the city. They have to patch the breech. Otherwise, they are just recirculating.

[Ready4Change]

37. Yep.

Dependng on the size of the breach, they may be able to keep water levels down until it can be repaired.

However, if the breach is large enough there may be no way to repair in in the water flow. They may have to allow the city to flood fully, repair the breach in stilled waters, then pump things out.

I've no idea what kind of flows repairs can be effected in.

[Tin Man]

32. May be necessary to first allow city to flood

until water levels inside levee equalizes with level outside. Then repair levee, repair pumps, and begin pumping like mad. Probably take several days just to get to the point where pumping can begin, then many more days of pumping to empty the city.

I honestly expect it'll take a couple weeks before the city is dry again. Probably many months before services are restored. In the meanwhile, it'll be like some kind of third-world refugee camp, unless they decide to forcably evacuate everyone from the city (whereto, I dunno) until services can be restored - that might actually be the smartest move.

[TorchTheWitch]

36. pumped out where?

It's my understanding that the water gets pumped back into Lake Ponchatrain... which in this case would be stupid until (or unless) the levee is fixed and the lake water recedes.

Until this hurricane, I had no idea that New Orleans was a basin below sea level and practically surrounded by large bodies of water... seems to me that building a city there in the first place was the stupidest idea ever conceived.

[markus]

40. Back into the lake from whenceit came

*after* the breech is repaired and/or the lake levels receed to their normal tidal selves.

[htuttle]

44. I don't know whether New Orleans can be reclaimed and rebuilt or not

But I do know that there will be many more cities lost to the ocean in the coming decades.

This may, or may not, be the first of those. Too soon to tell.