Lessons Learned from Katrina: How Can Engineers Apply Them for the Future?

[Ivan Seeking]

Greg mentioned this in GD and it seems that there are innumerable lessons to be learned from this storm and the resulting devastation. While this is all fresh in everyone's minds, what have you seen that could have been done better or prevented altogether? What lessons are learned? How can or should engineers apply these lessons in future endeavors?

 

[russ_watters]

Eek - from an engineering standpoint, Greg's suggestion of abandoning the city is probably the most sound. The infrastructure (the levy system) was designed to withstand a cat3 hurricane and this storm was right at the limit of that. I suppose you could up the design criteria to a cat4 hurricane, but in the battle between the armor and the bullet, the bullet generally wins.

 

[Astronuc]

First of all, do not build dwelling and commercial structures in an area that is below the prevail water level. On the other hand, if one does, learn from the Dutch in the Netherlands - they seem to do it very well - but then they do not get Category 3 or 4 hurricanes.

People may remember the floods along the Mississippi many years ago. The several levees collapsed because they were undermined when they became water-logged. I suspect that was what happened here. So one of the big engineering question is - were the levees that broke properly maintained.

OK, assuming the levee can be breached - what is the backup? The pumps were not working. Why not? It might not have made a difference in the current situation though. Perhaps more pumps or pumps of greater capacity were needed.

Any engineer must understand the technology her or she is employing, and must also understand the environment in which the technology is applied.

The American Society of Civil Engineers gives a periodic report on the infrastructure in the US. It is generally poor, and has been getting poorer for some time.

Congested highways, overflowing sewers and corroding bridges are constant reminders of the looming crisis that jeopardizes our nation's prosperity and our quality of life. With new grades for the first time since 2001, our nation's infrastructure has shown little to no improvement since receiving a collective D+ in 2001, with some areas sliding toward failing grades. The American Society of Civil Engineers' 2005 Report Card for America's Infrastructure assessed the same 12 infrastructure categories as in 2001, and added three new categories. Access the complete Report Card with details on each infrastructure category and state infrastructure information.

- http://www.asce.org/reportcard/2005/index.cfm

The Army Corp of Engineers has suspended some important work because funds have been diverted to the war in Iraq - with huge profits going to Kellog, Brown and Root, a subsidiary of Halliburton. That kind of money could have been spent to upgrade the levees in New Orleans and many other domestic projects.

 

[hitssquad]

How can or should engineers apply these lessons in future endeavors?

www.monolithicdome.com

 

[faust9]

I tend to agree with the "Don't live were the water wants to be" philosophy. Man Vs Mother Nature has a time tested result---Mother Nature wins. We have very few successes when actually doing battle with the old gal. We do our best but just like the rumble in the jungle we are only punching at the better figher wearing ourselves down.

I remember a few years back when a developer somewhere along the Mighty Miss wanted the Army corp to build new levies and breaks to dry out a flood plane---key words being flood plane---to make way for a strip mall. That is just stupid IMHO because it's taking my good taxdollars to expand the economy in the form of Old Navy Jeans and booze at some remote location. More importantly, the project was slated to be placed on a FLOOD PLANE---it was doomed to fail at some point give historical precident. Live near a river---you get flooded from time to time.

Live 2 feet below sea level right next to the Gulf of Mexico then a major flood was all but enevitable. Build a wall for a Cat4 then along comes a cat5. Build for a cat5 then whoops here comes a tsunami or the wall fails(classis Zeppelin might I add). There is little we can do to prevent something like this except live where the water doesn't to begin with.


All of that aside the only solution is to throw another dollar at it. Obviously the Levies were subpar. Then need to be built stronger and higher. The pumps were not up to snuff. Then need to be larger and probably from the looks of things designed to keep the flood plane dry in the face of 1 failed levy. A city evacuation plane needs to be put into place. The one used was inadiquate from what I saw on the news. Long linens with zero vehicle movement is what we'd expect; however, that doesn't make it right. I'm sure if a nuclear reactor was in the area and alarms started going off then traffic jams would probably not have been as bad. The levies---if designed for a cat three with a cat3-4 storm rolling in should have been suspect from the beginning. The news and officials were too relieved when the storm pushed east at the last minute---wrong. I was sitting at home and said to my wife that the area should be evacuated COMPLETELY and all caution should have been taken instead of false hope immediatly after the storm passed. It was a poor poor decision to let anyone stay and an even worse decision to hail the victors 10 minutes after the storm passed if bit a few feet to the right.

 

[Ivan Seeking]

According to the mayor of NO, and I don't know exactly how this is measured, but he stated that the storm surge drops one foot for every acre of intervening wetlands.

Also, don't forget, NO is just one town involved in all of this. Even if we ignore the general interpretation of Global Climate Change, meteorologists are predicting decades of increased storm activity as compared to our current definitions of "normal" activity. Of course, to me it seems reasonable to begin incorporating GCC into our thinking.

 

[FredGarvin]

Honestly, I don't think there are many lessons learned from an engineering standpoint, basically because of what Faust has already stated. Nature will win no matter what. Water will go to where it wants to eventually. Even looking at Biloxi, MS there's nothing really that can be designed to keep 8 feet of water from destroying everything you own. Mostly I see lessons learned for preparedness, evacuation schemes and recovery plannings.

With the current methods of thinking, especially when it comes to business and money, upgrading things like levees are not on the radar, even if they did have the money. If something has worked up to this point, why would anyone throw money at it? It always takes an event like this to point out shortcomings.

 

[Clausius2]

What I don't really understand is why there are some stubborn people who keeps on building below sea level, knowing this is a zone prone to floods and hurricanes.

I think that to prevent this situation there is needed some of more money, but constructors usually don't want to think of it. The SuperDome almost didn't resist the wind, it is something unbelievable.

Anyway this kind of great disasters are almost unavoidable. The best thing one can do is to run away from the zone. Now, Bush and the insurance companies are going to practise a well known field of engineering: economics engineering.

 

[LURCH]

I don't think bigger pumps would help. The pumps they had were adequate for almost any amount of rainfall, and once the levy breaks, no pump would help (for one thing, where would you pump the water to?).

Reinforcing the levy would be possible, but probably expensive. The idea that immediately came to my mind was to sink a cement barrier from near the crest of the levy (just a little bit to the "wet" side) all the way down to bedrock. If water can't soak through and undermine the base of the levy, it will probably hold.

But I think what is really needed is a more effective means of repair. I saw News reel footage of a busted Dyke (in Japan, I think) and it just happened that this particular Dyke had a railway running across the top of it. The emergency workers coordinated with the railroad to drive boxcars filled with scrap iron and other heavy payloads off the end of the railway. They just kept throwing railroad cars at it until they plugged the whole. Counties in which populated areas depend on a levy to protect them from flooding should have some means of repairing the levy available and ready for quick deployment. Until the hole is patched the waters can't recede, rescue work is hindered, neither can permanent repairs to the levy get started.

 

[arildno]

I totally disagree with those who essentially say that N.O. ought to be evacuated.
The mere fact that in the French Quarter, for example, there are lots of buildings from the 18th-19th century still standing shows that on the whole, the risk of building there is minimal, considering events in a longer perspective.

Freak events do occur, it doesn't follow that one should let them rule our building practices.

 

[mezarashi]

Freak events do occur, it doesn't follow that one should let them rule our building practices.

Well, evacuation and abandonment are two different things. I think that complete evacuation would have been the best choice. There's nothing you can do about it by staying back, as staying back will not help prevent your house from being torn apart, flooded, etc. In addition, you need to make sure you and your family survive it through with food, water, etc.

On the other hand, although I would like to advocate not going up against mother nature, I understand that people have a way of life and attachment to a place, so let them live where they want. If our technology allowed, I guess there would be people who would want to live on the Moon. I understand however, that these people keep in mind the risks involved, that their houses and everything they've lived for can be swept away. It's a threat they must accept the same way we know we can die in a car accident yet we drive, the same way we know we can die of a terrorist attack, but we continue on with our lives. Of course we try the best we can, technologically, to prevent disaster, but technology has shown its limits time and again unfortunately.

 

[arildno]

But the fact is that if there had been a great risk living in the French Quarter of New Orleans, those houses would have been destroyed ages ago by similar events.
Since they're still standing, it shows that in a 200-year perspective, it is, in fact, quite safe to settle down in New Orleans.

 

[Astronuc]

But the fact is that if there had been a great risk living in the French Quarter of New Orleans, those houses would have been destroyed ages ago by similar events.
Since they're still standing, it shows that in a 200-year perspective, it is, in fact, quite safe to settle down in New Orleans.

This is somewhat true. But the boundary conditions have changed in 200 years.

The development in the region has changed the flow of the Mississippi delta. There used to be more places for water to run-off. Now many places are developed, so the water has to go either into the Mississippi River or Lake Ponchatrain, which can only take so much from other areas, or not at all if a strong hurricane and tidal surge come along.

Also, the infrastructure is older. One would expect a certain level of maintenance. The infrastructure is not being properly maintained. How can I say this? Well, the levees broke, when they should not have. Perhaps the design was/is inadequate - and that is an engineering matter.

The environment is what it is, and we can't quickly change it the way we want it.

I suspect there has been plans to improve (and perhaps maintain) the levees, but these were deferred (deferred maintenance has destroyed many industries in the US, e.g. railroads during the 1960's-1980's).

I agree with others, no one should be building homes and business in areas that are prone to flooding. I know from example around Houston, Tx, where areas that were ostensibly in a 100-yr flood plain, began flooding several times per decade. This happened because stronger storms increased in frequency, the surrounding development reduced the capacity of the area to absorb water, and in some cases the ground actually subsided because of the huge amounts of water that have been removed from underground aquifers.

It is both a matter of public policy, as well as engineering, and engineers need to be heard in the public forum.

-----------------

It makes me ill and angry to see what has happened along the Gulf Coast, particularly in New Orleans, because much of it could have been avoided. All the death and destruction, and the economic cost, could have been prevented.

We can't bring back all those people who died.

 

[arildno]

Well, I don't know whether flooding is a recurring problem in the New Orleans area; if it is, then that certainly is relevant on its own "merit".
However, I am not that sure if that can be regarded as a lesson drawn from the Katrina event.

 

[ohwilleke]

The notable thing about Katrina is that it was not a surprise. Cat 4+ hurricanes happen, regularly. One was going to hit NO sometime or other.

One can engineer around some of these issues. In Okinawa, buildings are put above sea level and made out of reinforced concrete. They laugh at comparable storms. In Boston, they filled in the land until it was above sea level. Along Cherry Creek in Denver, where I live, near the flood plain, some of the newer apartment buildings sit atop parking garages, so that if the Creek does flood, it simply fills a parking garage with muck, and they turned flood plain itself into a park. Modern urban planning calls for using the areas most vulnerable to flooding as parks.

New Orleans can rebuild without being entirely stupid about it.

* Some neighborhoods, which are the furthest below sea level and least historic, should be razed and turned into parks that can double as drainage areas. Other less historic neighorhoods should be infilled before being rebuilt.
* Likewise, don't rebuild every single suburb -- NO needs wetland space surrounding it, to buffer rainfalls and storm surges. The metro area needs greenbelts.
* Every significant public building and apartment complex should have a back up power supply system and back up water supply system.
* New buildings should be built to withstand a Cat 5 hurricane with only minor damage.
* Mobile homes should be banned within 50 miles of the coast in every state within the hurricane zone.
* The electrical delivery system should be rebuilt in places where fallen wires won't do much harm.
* Don't put your primary shelter for people who don't have the means to evacuate, which was the Superdome in this case, in a flood plain with no high ground escape route attached to it. And, take extra care to insure that your primary emergency shelters can function even when the water, sewage, power grid collapses.
* Build attics with roof escapes. Mandate roof escapes in the building code.
* Pre-emptively shut down natural gas lines and the electrical system (or at least large segments of it) when facing a massive hurricane hit, in order to prevent fires and live wires in the aftermath.
* Reconsider rebuilding the most vulnerable bridges.
* Consider building a levee to segregate industrial areas like oil and gas facilities from urban/commercial areas, in the event of flooding.

 

[kdinser]

I'll agree 100%, Iraq, huge mistake. On the other hand, do you seriously think that if the money was not being spent on Iraq, it would have been spent to prevent this disaster? No chance, it would have been wasted and abused somewhere else.

The real enemy here is complacency. We dodged the bullet before, so of course, we will dodge it every time it comes. Sounds like a friend of mine who has just been arrested for DUI for the 5th time.

As far as rebuilding goes, of course they will rebuild. Then, when it happens again, people will actually stand and wonder what they have done to deserve this tragedy.

 

[russ_watters]

But the fact is that if there had been a great risk living in the French Quarter of New Orleans, those houses would have been destroyed ages ago by similar events.
Since they're still standing, it shows that in a 200-year perspective, it is, in fact, quite safe to settle down in New Orleans.

Well, I just read that the levee system in the Netherlands is built to withstand a 1250 year flood. 200 years (if that's the actual criteria) just isn't enough when you're talking about the damage that can be done to a modern city. They rolled the dice on, say, a $10 billion levee system and lost perhaps $100 billion due to the damage.

 

[faust9]

I'd like to add that arildno's point about the French Quarter is meaningless because the French chose that area for a city because it was the highest point in the entire flood plane. So, if the highest point STILL got flooded then the rest of the area REALLY got flooded(the 80% of NO underwater stat plays that out too).

 

[Ivan Seeking]

Here's an easy one that has come to my attention. Not really engineering so much as a disaster planning issue, but one problem cited often is that survivors don't know where the rescue centers and relief supplies are found. It seems seems that something as simple as a big white helium balloon with a bright red cross could be set aloft as a marker easily seen from miles around.

When the evacuation order was first given, it also seems that evacuation busses should have been rushed in for those who were unable to evacuate due to age, health, or other reasons.

 

[russ_watters]

When the evacuation order was first given, it also seems that evacuation busses should have been rushed in for those who were unable to evacuate due to age, health, or other reasons.

Ie, "mandatory evactuations" need to be a little more mandatory.

 

[Ivan Seeking]

Ie, "mandatory evactuations" need to be a little more mandatory.

But beyond that, many people simply didn't have the means to go anywhere.

 

[Ivan Seeking]

a related article

In the wake of Hurricane Katrina's devastation, some Americans--particularly Gulf Coast residents--may be wondering whether there are places in the U.S. that are safe from such natural disasters.

The short answer? No [continued]

http://www.forbes.com/realestate/2005/08/30/safestplaces-insurance-realestate-cx_sc_0830home_ls.html

 

[ohwilleke]

But beyond that, many people simply didn't have the means to go anywhere.

Indeed. Juxtapose this. In one part of New Orleans, a long line of school buses now submerged. In another part of New Orleans, tens of thousands of people in the Superdome because they lacked transportation to leave the city.

 

[ohwilleke]

Well, I just read that the levee system in the Netherlands is built to withstand a 1250 year flood. 200 years (if that's the actual criteria) just isn't enough when you're talking about the damage that can be done to a modern city. They rolled the dice on, say, a $10 billion levee system and lost perhaps $100 billion due to the damage.

In contrast, the New Orleans levees were built to handle a Category 3 Hurricane. Needless to say, that is not a 200 year event, or even a 1250 year event. (BTW, floods and hurricanes tend to have logorhythmic frequency-magnitude distributions, which is how 100 year and 500 year flood plains, e.g., are determined, if you know the frequency of low severity events you can usually make a best log fit approximation that is very accurate).

 

[arildno]

Well, from what I thought, N.O. has never experienced any thing like Katrina before.
Having that as a premise, I really can't see much reason for labeling life in N.O. as unsafe, UNLESS you have reason to believe that similar events like Katrina will occur more frequently in the future than they have done in the past.

If the premise is wrong, i.e, that N.O. is facing flodings and hurricans on a regular basis, that's a whole different story.

 

[FredGarvin]

There was a story on last night's news about a local guy who was stationed in Biloxi the last time it was destroyed by a hurricane ('64 I think). So it is not a one time event for Mississippi anyways.

Of all the footage I see on the news, it seems like there is a large percentage of people in N.O. that are even incapable of helping themselves. Perhaps it's just the clips I keep seeing, but it makes it seem like N.O. was populated by morbidly obese people that have respiratory problems. I would think it would take weeks of evacuation efforts to move them alone since they obviously can't move themselves. IMO that is a daunting task.

I would be very surprised if the levee system there is not going to be upgraded to handle exactly the level storm Katrina was.

I would tend to disagree with Ivan's Forbes link. Detroit, apart from the occasional snow storm, really doesn't get hit with natural disasters. The manmade disasters are much more frequent though!

 

[russ_watters]

Well, from what I thought, N.O. has never experienced any thing like Katrina before.
Having that as a premise, I really can't see much reason for labeling life in N.O. as unsafe, UNLESS you have reason to believe that similar events like Katrina will occur more frequently in the future than they have done in the past.

If the premise is wrong, i.e, that N.O. is facing flodings and hurricans on a regular basis, that's a whole different story.

I don't know if the exact conditions have been met before, but from http://www.nhc.noaa.gov/pastdead.html , I count 3 similar events and several near-misses in the past century.

What was a little unique about this one, as I understand it, is that while the hurricane backed-down from cat5, the storm surge remained on par with a cat5 storm.

 

[hitssquad]

What was a little unique about this one, as I understand it, is that while the hurricane backed-down from cat5, the storm surge remained on par with a cat5 storm.

Reportedly, the fact that it slowed down to 12 MPH helped it build up the surge. If it had come in faster, the surge would have been smaller.

 

[arildno]

I don't know if the exact conditions have been met before, but from http://www.nhc.noaa.gov/pastdead.html , I count 3 similar events and several near-misses in the past century.

What was a little unique about this one, as I understand it, is that while the hurricane backed-down from cat5, the storm surge remained on par with a cat5 storm.

Thanks for the links, russ.

 

[Astronuc]

I posted some links to US hurricane history here -

https://www.physicsforums.com/showthread.php?p=731458#post731458


What has happened has been predicted for sometime - and was emphasized in Aug 1992 with hurricane Andrew (also a Category 5).

Also - NOAA RAISES THE 2005 ATLANTIC HURRICANE SEASON OUTLOOK
Bulk of This Season's Storms Still to Come

http://www.noaanews.noaa.gov/stories2005/s2484.htm

The Atlantic has become steadily 'warmer' during the past few years, and is the warmest its been in a long time, which means the probability of Cat 4-5 hurricanes has increased.

What will happen when we have another Andrew/Katrina?