# Katrina: Why did the levies fail? **URL:** \ **Category:** Great Debates\ **Created:** [September 13, 2005, 1:03am UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367 "2005-09-13T01:03:14Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![smiling\_bandit](https://avatars.discourse-cdn.com/v4/letter/s/e9a140/32.png) [@smiling\_bandit](https://boards.straightdope.com/u/smiling_bandit)\ **Post date:** [September 13, 2005, 6:56pm UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/21 "2005-09-13T18:56:43Z")
> [@](#): > > One guy said flat out that it was Bush’s fault, that taking money from the ACoE to fix the levies was the direct cause of the collapse. Several people said this was bullshit, that there were 2000 miles of levies and that even if they were completely up to snuff they were only rated for a CAT 3 storm…and it wouldn’t have made a difference. One guy said that unless the proposed $14 Billion was spent, nothing would have saved the city. Even being a Bush supporter, I wish that I could just blame on one man, even him. Basically, though, the levees were a bad idea as constructed, they were not nearly strong enough because of widespread lack of foresight, and needed years of work. Plus, Louisiana was spending vast amounts of money which should have gone to levies on crap makework to bring home the pork. The problem here has little to do with Bush (or any national agency). It’s mostly a problem with the kind of pork spending in COngress, a lack of realistic thinking at the state level, and bureaucratic incompetence. Note that overtopping was expected and not really a problem. This is distinct from the breach, which occured at the worst possible time. The major tourist-loved part of NO is intact. Mostly the neighborhoods which grew up around it got flooded. If nothing elkse, we may as well allow the river to move as it wishes (IIRC, to the west) and rebuild there. And no more of this levee stuff. Use public planning offices to force the residences to stay well back from the docks. Let the river flood as it needs, depositing silt all over to replenish the landscape. ---
**Author:** ![Mtgman](https://avatars.discourse-cdn.com/v4/letter/m/b5a626/32.png) [@Mtgman](https://boards.straightdope.com/u/Mtgman)\ **Post date:** [September 13, 2005, 7:03pm UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/22 "2005-09-13T19:03:41Z")
Abdication of responsibility for/interest in the levee situation in New Orleans by citizens of California, or Texas, or damn near everywhere but New Orleans(where they knew and cared about it) is not only to be expected, it is damn near required by the socio-political system we live under in the US. Responsibility for tracking and dealing with these sorts of issues is exactly why we have vested so much power in our governments(local, state, federal). I, or you, didn’t NEED to care PERSONALLY, we had paid our taxes and elected our officials to provide those services on our behalf. Americans pay billions of dollars a year to the government and maintain a bureacracy of thousands upon thousands of full-time government employees so we don’t have to worry about the levees in New Orleans, the parks in Yellowstone, the storm sewers running under our driveways. I see nothing out of the ordinary in this aspect of the situation. The sheer amount of stuff, sometimes even important stuff like the levees which keep us alive when it floods, we have turned over to the government is mind-boggling. Rational Ignorance rules the day, as is almost necessary. Thanks, Steven ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [September 13, 2005, 9:12pm UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/23 "2005-09-13T21:12:36Z")
> [@Scylla](#): > > The thesis of the book is that disasters are inavoidable when we start working with complexity and large forces. These, and these alone are the two main components to disaster. > … > > … > Generally after a disaster, safety systems are installed to protect against that type of disaster. The safety system adds complexity. Typically something else fails and they build another safety system to protect against **that.** > > You reach a point where the complexity has grown geometrically because of all the safety systems and at that point it is usually the failure of a safety system or a malfunction in it that causes that disaster. > > A case in point is made about airplanes. Almost nobody has an accident with an open prop plane. It is clearly dangerous to be near that prop, and so people mind it and stay away. When turbines started being used they were encased. They no longer appeared as dangerous and people did not mind them as much, and now people fall into them all the time. Not exactly. When I was studying civil engineering, not surprisingly the topic of failure of complex systems comes up extensively. By your books logic, a 747 with it’s complexity should be much more dangerous than a Cesna or WWI biplane. They are, in fact, much safer. What matters is “factor of safety”. Basically it is how close we push the envelope with any type of structure or system. The difference between a 747 and a space shuttle is not in it’s complexity but in how forgiving the environment is that each operates in. A 747 can tolerate a lot more going wrong than a space shuttle. Redundant systems increase our factor of safety and reduce the probability of a catastrophic failure (everythings about probability) PROVIDED the systems are independent enough that the failure of system doesn’t create a cascade effect (like the entire computer crashes if one sensor fails). Usually when something complex fails, it is usually due to either a failure in a manner not expected or multiple systems failing simultaneously, the failure of any one or several not enough to cause a total catastrophic failure. A levee is not a particularly complex system. It is essentially just a big wall. But big enough waves crashing against it could cause one to fail in any number of ways - impacting some heavy object like a barge against it, eroding the foundation, or simply just knocking it over. ---
**Author:** ![jshore](https://avatars.discourse-cdn.com/v4/letter/j/b5e925/32.png) [@jshore](https://boards.straightdope.com/u/jshore)\ **Post date:** [September 14, 2005, 12:47am UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/24 "2005-09-14T00:47:22Z")
> [@smiling bandit](#): > > Note that overtopping was expected and not really a problem. Well, this prescient description from a [url=]National Geographic article from October 2004, describing an imaginary scenario very similar to what occurred except with overtopping rather than breaching, makes it sound otherwise: > [@](#): > > As the whirling maelstrom approached the coast, more than a million people evacuated to higher ground. Some 200,000 remained, however—the car-less, the homeless, the aged and infirm, and those die-hard New Orleanians who look for any excuse to throw a party. > > The storm hit Breton Sound with the fury of a nuclear warhead, pushing a deadly storm surge into Lake Pontchartrain. The water crept to the top of the massive berm that holds back the lake and then spilled over. Nearly 80 percent of New Orleans lies below sea level—more than eight feet below in places—so the water poured in. A liquid brown wall washed over the brick ranch homes of Gentilly, over the clapboard houses of the Ninth Ward, over the white-columned porches of the Garden District, until it raced through the bars and strip joints on Bourbon Street like the pale rider of the Apocalypse. As it reached 25 feet (eight meters) over parts of the city, people climbed onto roofs to escape it. > > Thousands drowned in the murky brew that was soon contaminated by sewage and industrial waste. Thousands more who survived the flood later perished from dehydration and disease as they waited to be rescued. It took two months to pump the city dry, and by then the Big Easy was buried under a blanket of putrid sediment, a million people were homeless, and 50,000 were dead. It was the worst natural disaster in the history of the United States. > > When did this calamity happen? It hasn’t—yet. But the doomsday scenario is not far-fetched. ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [September 14, 2005, 12:50am UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/25 "2005-09-14T00:50:54Z")
I guess it COULD have been a lot worse then. 50,000 dead? Yikes! :eek: -XT ---
**Author:** ![Hentor\_the\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/h/8edcca/32.png) [@Hentor\_the\_Barbarian](https://boards.straightdope.com/u/Hentor_the_Barbarian)\ **Post date:** [September 14, 2005, 1:34am UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/26 "2005-09-14T01:34:04Z")
> [@John Mace](#): > > Just FYI, this is the jist of the article: Does that strike you as a logical argument, **John Mace**? Really? I would just follow up on **Mtgman’s** point and ask you, did you worry about the Three Mile Island nuclear facility\* today? If there was a core breach there today, and someone told you, “Hey, nobody anticipated that the core could melt down,” and you found out that funding for upkeep of the containment system had been cut, wouldn’t you have questions about how wise that was? Or would such criticism be unfair since you haven’t really been giving any particular thought to Three Mile Island recently? \*Feel free to substitute in any place or signficant safety risk in the US for the sake of argument. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [September 14, 2005, 3:54am UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/27 "2005-09-14T03:54:50Z")
> [@Hentor the Barbarian](#): > > … did you worry about the Three Mile Island nuclear facility\* today? If there was a core breach there today, and someone told you, “Hey, nobody anticipated that the core could melt down,” and you found out that funding for upkeep of the containment system had been cut, wouldn’t you have questions about how wise that was? Much as I think Bush is incompetent I don’t agree that the levee’s broke because his administration cut funding for upkeep. The funding was cut because that’s the way people do things. Routine maintainance and modernization of the public infrastructure is always cut, delayed or posponed indefinitely. Plenty of past federal executives had ample opportunity to upgrade the levee system to withstand bigger storms and also didn’t do it. No politician who wants to be reelected is going to spend the money of today’s taxpayers on things that might only benefit that taxpayers grandchildren, if then. ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [September 14, 2005, 5:10am UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/28 "2005-09-14T05:10:44Z")
I’m guessing that now, after the shock of Katrina, money will be allocated for a heavier duty levee system…maybe even one that will go up to CAT 5. Its always in hindsight that we do these kinds of things. I guess we dodged a bullet here though, at least from a human deaths perspective. If it COULD have been 50,000 deaths then we were damn lucky that it wasn’t. Maybe the government at all levels didn’t screw the pooch quite as bad as we thought…or maybe we WERE just lucky. -XT ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [September 14, 2005, 1:21pm UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/29 "2005-09-14T13:21:22Z")
> [@xtisme](#): > > I’m guessing that now, after the shock of Katrina, money will be allocated for a heavier duty levee system…maybe even one that will go up to CAT 5. Its always in hindsight that we do these kinds of things. > > I guess we dodged a bullet here though, at least from a human deaths perspective. If it COULD have been 50,000 deaths then we were damn lucky that it wasn’t. Maybe the government at all levels didn’t screw the pooch quite as bad as we thought…or maybe we WERE just lucky. > > -XT Probably so because of the drama of the event. But we tolerate that number of deaths in autos every couple of years while driving recklessly and the industry digs in its heels against vehicle safety improvements. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [September 14, 2005, 3:30pm UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/30 "2005-09-14T15:30:20Z")
> [@xtisme](#): > > I’m guessing that now, after the shock of Katrina, money will be allocated for a heavier duty levee system…maybe even one that will go up to CAT 5. Its always in hindsight that we do these kinds of things. Let’s wait until we see what the bill (in $$) will be to do so, first. And keep in mind that it’s more complicated than just builildng bigger levees. The bigger they are, the heavier they are, and the levees themselves are sinking (like the rest of the city). And guess which sinks faster-- bigger leveees or smaller one. Today’s “Cat 5” levees could be “Cat 4” within a decade or so. Add to that the uncertainty of knowing what a Cat 5 levee is in the first place, and how long it will take to reach that point (I’ve heard estimates of up to 20 years) and there’s plenty of room for politics to take over again. ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [September 14, 2005, 3:34pm UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/31 "2005-09-14T15:34:11Z")
> [@John Mace](#): > > Let’s wait until we see what the bill (in $$) will be to do so, first. And keep in mind that it’s more complicated than just builildng bigger levees. The bigger they are, the heavier they are, and the levees themselves are sinking (like the rest of the city). And guess which sinks faster-- bigger leveees or smaller one. Today’s “Cat 5” levees could be “Cat 4” within a decade or so. Add to that the uncertainty of knowing what a Cat 5 levee is in the first place, and how long it will take to reach that point (I’ve heard estimates of up to 20 years) and there’s plenty of room for politics to take over again. I agree. I’m not advocating (necessarily…certainly not without study) that this is what we SHOULD do…I’m stating that this is most likely what we WILL attempt to do. Simply pour money at the problem and build ‘bigger levees’ as you say. Its the normal hindsight reaction to an event like this…attempting to close the barn door after the horse got away. -XT ---
**Author:** ![CBCD](https://avatars.discourse-cdn.com/v4/letter/c/9fc348/32.png) [@CBCD](https://boards.straightdope.com/u/CBCD)\ **Post date:** [September 14, 2005, 7:17pm UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/32 "2005-09-14T19:17:01Z")
It might be interesting to learn a bit about who decides what projects the Army Corp of Engineers should work on, i.e., where to spend the money. [This](http://www.washingtonpost.com/wp-dyn/content/article/2005/09/07/AR2005090702462.html) article in the Washington Posts suggests that Louisiana itself did not choose to spend all Army Corps resources on the levees. Also see ‘Senators in Deep Shit,’ and ‘Sen. Mary Landrieu (D-La.)’ for more information. In Katrina’s wake, Louisiana politicians and other critics have complained about paltry funding for the Army Corps in general and Louisiana projects in particular. But over the five years of President Bush’s administration, Louisiana has received far more money for Corps civil works projects than any other state, about $1.9 billion; California was a distant second with less than $1.4 billion, even though its population is more than seven times as large. Much of that Louisiana money was spent to try to keep low-lying New Orleans dry. But hundreds of millions of dollars have gone to unrelated water projects demanded by the state’s congressional delegation and approved by the Corps, often after economic analyses that turned out to be inaccurate. Despite a series of independent investigations criticizing Army Corps construction projects as wasteful pork-barrel spending, Louisiana’s representatives have kept bringing home the bacon… In fact, more than any other federal agency, the Corps is controlled by Congress; its $4.7 billion civil works budget consists almost entirely of “earmarks” inserted by individual legislators. The Corps must determine that the economic benefits of its projects exceed the costs, but marginal projects such as the Port of Iberia deepening – which squeaked by with a 1.03 benefit-cost ratio – are as eligible for funding as the New Orleans levees . ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [September 15, 2005, 6:00pm UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/33 "2005-09-15T18:00:55Z")
I was struck by the Army Corps apparent passivity in actually _defending_ the levees of New Orleans (see post#9). The Chief of Engineers now suggests that [this was an error:](http://www.washingtonpost.com/wp-dyn/content/article/2005/09/15/AR2005091501131.html) > [@](#): > > The government should have pre-positioned more sandbags and helicopters in the New Orleans area before Hurricane Katrina struck so that repairs to broken levees could have started sooner, the commander of the Army Corps of Engineers said Thursday. > > “In retrospect I would say yes, we could have, we should have, in anticipation of this,” Lt. Gen. Carl Strock told a Pentagon news conference. > … > “The people who would normally be up on the levees looking for weak spots and respond immediately were gone from the city,” he said. “So that is one of the things that made it difficult for us to respond here.” The conference transcript isn’t up at the pentagon yet. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [September 15, 2005, 6:50pm UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/34 "2005-09-15T18:50:18Z")
Times Picayune this AM: Mystery surrounds floodwall breaches Could a structural flaw be to blame? > [@](#): > > One of the central mysteries emerging in the Hurricane Katrina disaster is why concrete floodwalls in three canals breached during the storm, causing much of the catastrophic flooding, while earthen hurricane levees surrounding the city remained intact. > … > Suhayda said that his inspection of the debris from the 17th Street Canal breach suggests the wall simply gave way. “It looks to have been laterally pushed, not scoured in back with dirt being removed in pieces,” he said. “You can see levee material, some distance pushed inside the floodwall area, like a bulldozer pushed it.” > > He suggested that because the walls failed in a few spots, the flaw may not be in the design but in the construction or materials. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [September 16, 2005, 1:08am UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/35 "2005-09-16T01:08:17Z")
> [@xtisme](#): > > I’m guessing that now, after the shock of Katrina, money will be allocated for a heavier duty levee system…maybe even one that will go up to CAT 5. Its always in hindsight that we do these kinds of things. > > I guess we dodged a bullet here though, at least from a human deaths perspective. If it COULD have been 50,000 deaths then we were damn lucky that it wasn’t. Maybe the government at all levels didn’t screw the pooch quite as bad as we thought…or maybe we WERE just lucky. > > -XT It wouldn’t matter if they made the levees out of stainless steel. A cat-5 storm would go over the top of them. Storm surges create a forward moving body of water that will move up a hill. In the case of NO, the passing hurricane would dump water North of the city which would then run back into Lake Ponchetrain. Thus hitting the city again with a gravity fed storm surge. What I have been curious about from day one is what type of control structures (if any) exist at the ends of each canal. I can’t tell from looking at [satellite photo’s](http://www.flickr.com/photos/jomatt/38669580/in/photostream) what the structure is (at the head of the 17th St Canal) but it doesn’t look substantial. A good floodgate would seal off the canal from the lake. Any damage from a canal levee breech would be limited to the water in the canal. The city pumps could easily handle this. FYI - there are a number of good before/after images at the site link and you can click on the magnifying glass in the upper left of the picture and download a larger version. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [September 16, 2005, 1:17am UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/36 "2005-09-16T01:17:01Z")
I’m really wondering how long it acually will take to build up the levees to be capable of withstanding a Cat 5 storm. If it’s 20 years (as one “expert” I head say), I would be concerned that the city might get rebuilt, and another Cat 5 storm hits before the levees are finished. Do we then rebuild the city _once again_ (assuming similar floods would ensue)? ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [September 16, 2005, 1:25am UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/37 "2005-09-16T01:25:17Z")
I guess its a matter for probability statistics then. What are the actual odds of a CAT 5 storm hitting the right zone to effect NO the way Katrina did? How often do such things happen. Anyone have any idea? -XT ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [September 16, 2005, 1:27am UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/38 "2005-09-16T01:27:30Z")
> [@John Mace](#): > > I’m really wondering how long it acually will take to build up the levees to be capable of withstanding a Cat 5 storm. If it’s 20 years (as one “expert” I head say), I would be concerned that the city might get rebuilt, and another Cat 5 storm hits before the levees are finished. Do we then rebuild the city _once again_ (assuming similar floods would ensue)? I think you missed my point. It doesn’t matter. Even if the levee’s hold, the water will physically move up and over them. Unless they raise them substantially higher nothing will help. BTW - I started going through the site I posted and found a [closeup](http://www.flickr.com/photos/jomatt/38658605/in/photostream/) of the breech area on the 17th St canal ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [September 16, 2005, 1:34am UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/39 "2005-09-16T01:34:39Z")
> [@John Mace](#): > > I’m really wondering how long it acually will take to build up the levees to be capable of withstanding a Cat 5 storm. If it’s 20 year… From [today’s briefing:](http://www.dod.mil/transcripts/2005/tr20050915-3905.html) > [@](#): > > Q And more to the future, there’s obviously been a decision to rebuild New Orleans, as much of the Gulf Coast would be done. Do you have any idea, any ballpark figure, in terms of cost and time, if the levee system has to be rebuilt or you decide to rebuild it or redo it, to protect the city from a storm like this in the future, a Category 4 or a Category 5 storm – any ballpark figure on what it might cost and how long it might take to do that, sir? > > ``` > GEN. STROCK: Sir, there's a ballpark figure out there. We have been doing a study of what it would take to provide Category 4 and 5 protection to the city. > > ``` > > … > The results of that reconnaissance study indicate that there is a federal interest and that we think we should move into the next formal stage of the study, which is going into the actual engineering, economics and environmental aspects of this in a deliberate way. So we’re right at that tipping point of going into the deliberate study. And the ballpark that I think I recall was about $2.5 billion to raise to [Category] 4 and 5, but if I’ve got that wrong, I’ll correct that. But it’s something along that order. Now, with this storm, the approach we take may change, and it may be a more costly activity than that, but I think it’s something along those lines that we talked about. > > ``` > Q Well, how long could that take, sir? > > GEN. STROCK: Well, the study could take actually -- just the study itself could take years, and the actual implementation of the study could take many more years. Just to put this in context, the current hurricane protection system around New Orleans was first authorized in 1965. It went through a series of litigations. It really only began in earnest, in a modified form in 1975, so we've been about 30 years building these levees to get to this level. > > When you build a levee, you have to understand that the soils in the area -- and in the area of New Orleans the soil's very compressible. So the way we do these levees is we lay a section of the levee on it, and they will compress the soils and you'll get settlement; the levee itself settles, and then we'll go back in and put another lift on there. We can't put it all down at one time because you can have catastrophic results in the foundation. So it's a very long process. Typically, four or five years we wait between each segment of levee, so these don't happen overnight. It takes a number of years to put these kind of things in place. > > ``` ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [September 16, 2005, 1:34am UTC](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367/40 "2005-09-16T01:34:45Z")
> [@Magiver](#): > > I think you missed my point. It doesn’t matter. Even if the levee’s hold, the water will physically move up and over them. Unless they raise them substantially higher nothing will help. Not every post is directed at you. 🙂 I was just expounding in general, not responding to your post. But of course I meant that they would be raised higher-- or any other thing that must be done to have them withstand a Cat 5 storm (assuming we even know for sure how to do that). [Previous page](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367.md?page=1) [Next page](https://boards.straightdope.com/t/katrina-why-did-the-levies-fail/321367.md?page=3)