Skip to comments.Did Loose Barge Cause Levee Break? (Vanity).
Posted on 09/17/2005 1:02:44 PM PDT by Mike Darancette
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While I'm here, two other points, regarding the Industrial Canal Breach caused by the barge.
One, the barge is south of the hole, and the most likely surge came from the north, whether the Lake, the Intercoastal Waterway or both.
Two, the debris piles, in the second image in this thread, are lodged at chokepoints oriented radially away from the breach caused by the barge. That tells me that the great majority of the water in this area initially came from the breach that the barge caused. However, the picture clearly shows that the water is in fact flowing in the opposite direction, out of the breach and back into the hole.
Since water doesn't flow uphill, this may seem like a contradiction, but there is an explanation and I expect it to arrive with the revelations noted in my previous post. Probably late Monday or early Tuesday.
Do you mean into the canal? If so, yes it does. And it it did. The Lake level, and thus that in the canal went down after the storm surge had passed, leaving the water in the city higher than the water in the Lake/Canal. So the water in the city naturally flowed back through the breeches in the levees and into the canals and the Lake, until they were at the same level.
The barge slipping it mooring is an act of God only if He is the one who tied it up.
Something for the lawyers to argue about.
Before you run too far with this, if you are looking for culprits, give it a day or so. I have this feeling that some.....revelations....are inbound.
But you're such a tease too. :)
"Probably water coming up out of storm drains.) "
Water from storm drains in the city could not possibly fill these canals. Only a pump can raise water to a higher level. Water simply cannot flow from a lower to a higher and back to a lower topo region.
I'm not teasing ayone, scouts honor. After a storm like this, it takes several days for enough anecdotal evidence to build up to even begin asking the right questions. Then you start searching (meanwhile more data is coming in, so you have to keep up with that too), and the search process starts with viewing and discarding a great deal of chaff before you ever start getting to the meatier issues.
Then comes the point in time when you find the motherlode, a database, raw information, no spin included. It takes a little bit of time to spool up, to understand and organize what you've been given, and then begins the long process of hauling it in, plugging it into the big picture, and working your way around the...perimeter...of the problem.
At some point you have gained enough of the big picture to realize that you are on the downhill side of the slope, that more of the project has been completed than what remains. Then you can take a chance on predicting when you might be able to disseminate the collated data, and the conclusions drawn from it.
However, even once on the downhill slope, certain things have become obvious, and if, at that point in time, you see misconceptions being bandied around....well, you let it be known that this or that POV probably doesn't fit the data at hand, without jumping the gun and spreading false information based on a partial assessment yourself.
The water in Lake Pontchartrain dropped very slowly. On Flood Monday, the Lake was around 5 feet above normal, which put it at 6 feet above sea level. By the time the water equalized, achieved the same levels inside the breaches as outside, the Lake had only dropped to 3 feet above normal, 4 feet above sea level.
Even though I pointedly haven't mentioned the Industrial Canal levels in this post, I will say that the description of why the water was flowing out of the 9th ward breach would greatly benefit from the inclusion of an additional body of data which hasn't really made the mainstream media yet.
For starters, take a look at post 40 from this thread:
and then scan this one start to finish:
The first link includes an anecdotal timeline, and the broad picture of the dynamics of the storm's hydraulics, what water moved from where to where, when. The second begins to ask the questions I'm working on answering definitively now. Since both will need to have been assimilated to utilize what is coming, and since you asked for more info, this kills two birds with one stone and gets you a jump on what is yet to come.
Having stood at the foot of a nearly topped levee, augmented by about five feet of sandbags, maybe 25 feet below water level, on a mostly dry street, watching the entire wall "breath" with the flow of the water on the other side, I can tell you for a certainty that water does somehow find a way to rocket out of the storm drains down on your level, to the extent that the folks in charge had erected a three foot wall of sandbags around the "fountain", not to stop the water coming from the drains (if you tried the pipes would simply rupture elsewhere in an uncontrollable manner) but to allow it to trickle down the street instead of making a surge which would wreck most everything it came in contact with.
In fact, the top of the "fountain" is almost certainly equal to the water level on the "canal" side of the levee, minus "pipe friction".
This is consistent with the 0300 anecdotal language in the reports. Water problems, but not quite general flooding, not yet, not at that point in time.
Oh yes, almost forgot. This whole topic is sort of like an elephant in the living room. There are a lot of people with a lot more schooling in the subject, with a lot more hands on experience with this set of levees and this flood, or with much better access to data than I have, or various combinations of the above.
I'd guess that they mostly fall into one or more of three categories.
1. People who know what went wrong but choose not to distribute this information.
2. People who have a gut feel for what happened but choose not to distribute this information.
3. People who either know or have a gut feel for what happened but who are prohibited from distributing the information.
The first two groups may have valid or less valid reasons for choosing not to distribute the info. They might be busy unwatering the city. They might not feel qualified to offer an opinion. They might be in the middle of the same process I am, not wanting to spread false information until an overall assessment has been completed.
There is at least one circumstance where the third group is...defensible, primarily reporters who know what happened but who do not have enough hard data to satisfy their managing editors, who in turn have to keep the lawyers happy.
Fortunately, I am under no such restrictions, and have no compunctions about discussing my opinions and letting the chips fall where they may. Which brings me to the critical point.
I have not claimed any "truth" yet, and I probably will not. I have presented data, and have tied that data together with my OPINION of what it means. Opinions can be wrong, and I make no guarantees, express or implied, to any person living or dead, yada, yada, yada...
I don't post raw speculation though. I know how to classify information, bit by bit as it comes in, as to relevence and credibility, and I put my logical process out where they can be examined, assessed, discussed, and then either accepted or rejected by the individual viewer.
Two conclusions then, one I may be wrong, and two, I am far from the center of those who are "in the know" on this subject. They just aren't talking for the record yet.
"In fact, the top of the "fountain" is almost certainly equal to the water level on the "canal" side of the levee, minus "pipe friction". "
Apparently I misunderstood your original post. I understood it to say that your "fountains" were reversed. That is, storm drains 15 feet below sea level dumping water over a levee 15 feet above sea level for a total rise of 30 feet.
If that is the case all of the writings of Stokes, Navier and Bernoulli concerning fluid dynamics will have to be altered due to Katrina.
Being an E.E. makes me as far from an M.E. or C.E. as a fisherman, but 35 years ago all engineers were exposed to fluid dynamics.
Thanks, good pictures. I have to admit that a bardge is there.
Ok, I've got you. No, the leaking drains were letting water "through" the levee with the water coming up on the inside. Yes, we would have significant revision at hand if the reverse were true.
I'm not sure what the mechanism for the storm sewer leaks is, because they are below the level of the water outside the levee all the time but only leaked when the river ( in the case I cited) was at flood stage. Some sort of flowcock failure but I don't have any details there.
OT but memorable, for some reason standing under the levee was not nearly as intimidating as standing atop the levee and feeling it sway underneath me. It might have been being able to see the water, lapping near my feet on the river side, less than a foot from the top of the emergency sandbags, and looking down on the rooftops on the other.
Interesting story there. They let the kids out of high school because the city was "doomed" and the kids saved the city, moving something like more than three quarters of the necessary sandbags.
A friend and I, left with nothing to do after the pubs closed locally, made the three hour roadtrip for a visual inspection. Our engineering criteria were met, and we managed to escape with both our lives and a commemorative sandbag.
You are quite right, it takes a lot of time and energy to research and prove/disprove the many theories.
But I was.
I doubt it. New Orleans is no Kingdom! ;-)
Yes, we were, in addition to statics, dynamics, and thermodynamics. Strangely the only EE course the ME's, and I think CE's had to take was a two semester "intro to EE", whereas we were taking the same fundamental engineering mechanics, fluids and thermo as they were. But of course we got better grades in their courses than they did. :)
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