2011 Mississippi River Spring Floods

[CharlieK]

_ BK,
A couple of points for you to consider:

1) In '73 when the ORCS was flowing more than design capacity, it was no where near ultimate capacity. The opening was not fully submerged as you seem to indicate here. Several feet of freeboard existed at the Low Sill Structure. So much so that a barge with a dump truck on it were sucked through one of the openings. No water by-passed the structure (over, around, or under) and the "near-failure" that everyone remembers was actually on the river side of the structure and was a result of scour casued by eddies which had formed due to high velocities through the structure. The area of opening on the structure is considerably greater that what can be "safely" flowed through the structure.

2) Given that the area of opening was not completely flooded, an incremental increase in the head differential has a significant impact on the flow through the structure. In open channel weir flow equations the flow is the product of several terms including the head which is raised to the 3/2 power. So yes even a small increase in head (with tailwater remaining the same) has a significant impact on the flow through the structure. Similarly, if the upstream stage decerases by a foot and simultaneously the downstream stage (tailwater) decreases by a foot, it is possible that the same exact flow will be measured.

3) Finally, the ORCS of today is not what it was in '73. Since then, the auxillary structure has been built to distribute the flow between additional sturctures. If you look at a map or visit the facility, you can see that the orientation of the new structure is significantly different than the low sill structure. That is by design. In an instanteous snapshot, the low sill structure can flow a considerable amount of water, however the structure cannot maintain the stresses from that flow. In this configuration, water from the auxillary structure flows in a west/ nw direction. This orientation requires that the water flow "upstream" for a distance, which increases tailwater and decreases the flows and velocities through the structure. _

This is my favorite post so far, and says what I thought about a million times better than I did. Probably becuase it appears to have been written by a civil engineer who is an expert.

Cajun Civil, what is your take on the risk of the river changing course? (not necessarliy due to this event, but say if "project flood" ever actually happens)

[biged05]

No! It's not an indication of gates being closed. That's what I tried explaining to you about the morganza water not affecting Morgan city 9 hours after the gates were opened! The water from morganza doesn't touch the atch. River until at least south of sherbun if not south of BLR. It is impossible for you to see results from opening gates at morganza in morgancity 9 hrs later. Look at a map, ORC and morganza come into the basin at two different points and don't merge anywhere near simmsport. The only way simmsport, Melville, krotz springs and anything from BLR north gets affected is by the water getting slowed down south of BLR. I watched the water myself. The sat. It was opened the spillway was dry as a bone. The next day I saw it about a mile south of the structure creeping sliwly. The Tuesday after it was just south of the railroad that crosses into Melville. The next day it was just getting to hwy. 190. And so on. It just started merging with the atch. In the last couple of days! No do you understand the reason we doubt your theory of looking at those charts and making a determination that you've seen affects 9 hrs later?!


igeaux.mobi

[Bandwagon King]

_ No! It's not an indication of gates being closed. That's what I tried explaining to you about the morganza water not affecting Morgan city 9 hours after the gates were opened! The water from morganza doesn't touch the atch. River until at least south of sherbun if not south of BLR. It is impossible for you to see results from opening gates at morganza in morgancity 9 hrs later. Look at a map, ORC and morganza come into the basin at two different points and don't merge anywhere near simmsport. The only way simmsport, Melville, krotz springs and anything from BLR north gets affected is by the water getting slowed down south of BLR. I watched the water myself. The sat. It was opened the spillway was dry as a bone. The next day I saw it about a mile south of the structure creeping sliwly. The Tuesday after it was just south of the railroad that crosses into Melville. The next day it was just getting to hwy. 190. And so on. It just started merging with the atch. In the last couple of days! No do you understand the reason we doubt your theory of looking at those charts and making a determination that you've seen affects 9 hrs later?!


igeaux.mobi _

I am sorry to have upset you Big Ed. I uderstand that the water released in Morgaza does not mix with the river until it gets below the inner levees below I-10. There are channels that fill up along the way though & those channels were already full & backing up when the gates were open, weren't they? Is it not possible that before the water covered the ground between the East Atchafalaya levee & the outter east levee going down from Lavonia to Ramah that it was getting pushed down those channels at much higher speed rather than back filling from the River? Just saying. I won't bother you anymore about it though. Thanks for the job you do.

[CharlieK]

_ Ok Big Ed. I could see distinctly on every chart that I looked at down stream, whether it was either reading in Morgan City or the wax lake outlet at Calumet within 9 hours of gates being open the water rise at those gates & the effect of the opening of those gates. Now I read what you have written about the water not reaching Morgan City from Morganza, but I can tell you the signal & the rise would start within 9 hours. The water may not be travelling that fast but the hydraulic effect of what you are doing is. I can prove it by the charts.

Now I could theorize why this happens, but I won't I am simply stating that these charts are giving me all kinds of information of what is going on upstream. Otherwise, how would I know this stuff? I have been looking at these charts a grand total of a week in my life & I have pretty much been able to predict with 100% accuracy what is about to happen.When you get a chance, go back & look at this very thread & see when I called the crest up & down the river I was within like 10 minutes of it cresting in Knox landing & ahead of the crest in Natchez. That's when I knew yall had control of the river was Wednesday night. I'm not a self appointed soothsayer for goodness sake. I can read these things & I'm telling you they are sending radfio signals days ahead of what the river is actually doing. That is why the river may be cresting ahead of preditions & lower than predicted.

Now please listen to me. I have put up with an awful lot of abuse on here because this is very important to me. You know what that level means in Butte Larose much better than I. I am telling you the Corps has total control of this thing & doesn't need to put 24' of water in Butte Larose to get this river down where they want it. They already got it. I really don't want to see the damage done to the wildlife that will be done by letting this thing get over 23'. They could start closing gates now, but I aint trying to tell you how to do your job, I am just asking you, please look at the charts really really good & they will tell you that you've had control of this thing since Wednesday night. You can open & close gates at will & throttle this river down & look like heros in the process. _

Ya'll realize how he has positioned himself here, right? If his GUESS is correct that no more gates have to be opened, he will be "right" and if his GUESS is not correct and more gates do have to be opened then he will claim they didn't need to be, which cannot be proven once they are open.

He is an evil genius.

[biged05]

_ I am sorry to have upset you Big Ed. I uderstand that the water released in Morgaza does not mix with the river until it gets below the inner levees below I-10. There are channels that fill up along the way though & those channels were already full & backing up when the gates were open, weren't they? Is it not possible that before the water covered the ground between the East Atchafalaya levee & the outter east levee going down from Lavonia to Ramah that it was getting pushed down those channels at much higher speed rather than back filling from the River? Just saying. I won't bother you anymore about it though. Thanks for the job you do. _

Well I apologize for getting upset, but this is not a job I take lightly. Sometimes I do get a little too worked up over a job (as some people may see it), but I am very proud of who I work for and the job I do here, especially in times like this. (and there are a few people on here who can vouch for that) I've been known to give a piece of my mind to my own family members about the basin. (Even my wife went off on her family about the same time we opened morganza). I grew up just outside the basin, and spent a lot of time over my life time in there, so I hate to see this happen just as much as anyone else, but it is what it is.

As far as getting down the canals faster, no. it was the job of myself along with other co-workers here in my office to track where the water was as it was coming down for as long as possible, and that meant seeing where it was from the levees and drive down as far as you could into the basin to try and find it in canals or whereever it was. At some point in time, yes it got into canals and borrow pits that already had water in them and were connected, but in the upper part of the Spillway, the canals were just as dry as the fields so you could clearly see where the leading edge of the water was in the beginning. We could see it that way until somewhere south of 190. You could actually walk up to the leading edge of the water and touch it. One of my co-workers put said it all got into perspective when he was watching the water come down the field and there was one of those big black ants inches in front of the leading edge of the water just hauling @$$ as fast as it could, yet within the next few days we knew there would be 3 or more feet of water in that very spot.

I don't mind anyone asking me questions. You're not bothering me. I came here to educate anyone who wants to listen as best as I can, and if I don't have the answer I'll go find it (if I have time) or just say I don't know. At the same time, some things are just not as simple as they seem.

[Bandwagon King]

_ Ya'll realize how he has positioned himself here, right? If his GUESS is correct that no more gates have to be opened, he will be "right" and if his GUESS is not correct and more gates do have to be opened then he will claim they didn't need to be, which cannot be proven once they are open.

He is an evil genius. _

That's just wrong dude. I only want what's best for everybody like everyone else does. I know if they open any more gates it will only be because they had to. I hope Helmut isn't right, but I understand there's a good chance he is. It looks like the river levels are about to confirm whether he's right or not.

[jumboragncajun]

_ Well I apologize for getting upset, but this is not a job I take lightly. Sometimes I do get a little too worked up over a job (as some people may see it), but I am very proud of who I work for and the job I do here, especially in times like this. (and there are a few people on here who can vouch for that) I've been known to give a piece of my mind to my own family members about the basin. (Even my wife went off on her family about the same time we opened morganza). I grew up just outside the basin, and spent a lot of time over my life time in there, so I hate to see this happen just as much as anyone else, but it is what it is.

As far as getting down the canals faster, no. it was the job of myself along with other co-workers here in my office to track where the water was as it was coming down for as long as possible, and that meant seeing where it was from the levees and drive down as far as you could into the basin to try and find it in canals or whereever it was. At some point in time, yes it got into canals and borrow pits that already had water in them and were connected, but in the upper part of the Spillway, the canals were just as dry as the fields so you could clearly see where the leading edge of the water was in the beginning. We could see it that way until somewhere south of 190. You could actually walk up to the leading edge of the water and touch it. One of my co-workers put said it all got into perspective when he was watching the water come down the field and there was one of those big black ants inches in front of the leading edge of the water just hauling @$$ as fast as it could, yet within the next few days we knew there would be 3 or more feet of water in that very spot.

I don't mind anyone asking me questions. You're not bothering me. I came here to educate anyone who wants to listen as best as I can, and if I don't have the answer I'll go find it (if I have time) or just say I don't know. At the same time, some things are just not as simple as they seem. _

Thank You BigEd, that was a classy response.
I appreciate all the info.

[CharlieK]

_ That's just wrong dude. I only want what's best for everybody like everyone else does. I know if they open any more gates it will only be because they had to. I hope Helmut isn't right, but I understand there's a good chance he is. It looks like the river levels are about to confirm whether he's right or not. _

Don't worry, just kidding.



You aren't any kind of genius. (couldn't resist)


You are persistant though. However far persistance can take you though, it still doesn't make you correct. This isn't politics where if you keep saying the same lie over and over it becomes the accepted fact. (not that you are lying, just wrong).

Read the report thugh, it is hair raising. ORCS has been improved and hopefully it conintues to work as designed. Otherwise Katrina will look like Mardi Gras.

[Bandwagon King]

_ Don't worry, just kidding.



You aren't any kind of genius. (couldn't resist)


You are persistant though. However far persistance can take you though, it still doesn't make you correct. This isn't politics where if you keep saying the same lie over and over it becomes the accepted fact. (not that you are lying, just wrong).

Read the report thugh, it is hair raising. ORCS has been improved and hopefully it conintues to work as designed. Otherwise Katrina will look like Mardi Gras. _

Hahaha, hahaha, ha ha aha. That was funny...... I get it.

So you ready for round three? What does the Atchafalaya cresting today & tonight mean in all of this? are both rivers going to be in perfect haromony draining ever so slightly together? Does the Mississippi still dump an extra load into the basin that the basin will hold onto until further notice? Can the Mississippi even dump anymore water into the basin at present levels? What will be the threshhold for opening more gates & will it do any good?
What will be the threshhold for closing gates?

[Boomer]

_ Ya'll realize how he has positioned himself here, right? If his GUESS is correct that no more gates have to be opened, he will be "right" and if his GUESS is not correct and more gates do have to be opened then he will claim they didn't need to be, which cannot be proven once they are open.

He is an evil genius. _

As I read the C of Ds again-----Ignatius!!!! having said that Igie is a very smart dude---now his application?????

[LsuULfan]

_ Well I apologize for getting upset, but this is not a job I take lightly. Sometimes I do get a little too worked up over a job (as some people may see it), but I am very proud of who I work for and the job I do here, especially in times like this. (and there are a few people on here who can vouch for that) I've been known to give a piece of my mind to my own family members about the basin. (Even my wife went off on her family about the same time we opened morganza). I grew up just outside the basin, and spent a lot of time over my life time in there, so I hate to see this happen just as much as anyone else, but it is what it is.

As far as getting down the canals faster, no. it was the job of myself along with other co-workers here in my office to track where the water was as it was coming down for as long as possible, and that meant seeing where it was from the levees and drive down as far as you could into the basin to try and find it in canals or whereever it was. At some point in time, yes it got into canals and borrow pits that already had water in them and were connected, but in the upper part of the Spillway, the canals were just as dry as the fields so you could clearly see where the leading edge of the water was in the beginning. We could see it that way until somewhere south of 190. You could actually walk up to the leading edge of the water and touch it. One of my co-workers put said it all got into perspective when he was watching the water come down the field and there was one of those big black ants inches in front of the leading edge of the water just hauling @$$ as fast as it could, yet within the next few days we knew there would be 3 or more feet of water in that very spot.

I don't mind anyone asking me questions. You're not bothering me. I came here to educate anyone who wants to listen as best as I can, and if I don't have the answer I'll go find it (if I have time) or just say I don't know. At the same time, some things are just not as simple as they seem. _

biged:

Thanks again for all of the info-very interesting. Thinking about taking a drive this weekend to see as much of this stuff as I can-like taking a loop-driving 190 from Opel-then going over the Morganza spillway, then to the Old River Control Structure, back down and over the new Audubon bridge-then back to Lafayette on I-10 over the basin. Any recommendations on areas to try to see that are open to the public or areas to avoid that are closed to the public?

[biged05]

All the main roads you mentioned are open, but we're not letting the general public put at any of the structures except maybe the auxiliary structure on Saturday bit I'm not real sure about that either.
The loop you have catches Everything I can think of

igeaux.mobi

[cajun_civil]

_ This is my favorite post so far, and says what I thought about a million times better than I did. Probably becuase it appears to have been written by a civil engineer who is an expert.

Cajun Civil, what is your take on the risk of the river changing course? (not necessarliy due to this event, but say if "project flood" ever actually happens) _

Charlie,
I am by no means an expert on the Mississippi River and it changing its course. I will say that in the micro view, man has controlled the mississippi. Will man always win? There is only one person I know who has the answer to that. In the interim, the men and women of my profession will continue the good fight using scientific data and sound engineering judgement.

BigEd, Jumbo, or Helmut your thoughts?

[cajun_civil]

_ Thanks for your post. I was just skimming through that report myself & according to page 6 I believe they do note that there was a scour hole that went down some 130' & passed from the upstream side of the structure to the down stream side of it. I may be misreading, but the guy I talked to said they pushing junk cars off barges to attempt to fill the sink holes below the structure. I am greatful that this has been addressed & it seems as though the ORCS is working fine. I am going to assume this based on the Atchafalaya cresting at Simmsport. I will read through this report & thank you for your comments & will welcome your corrections. The report is pretty long & I plan on downloading it to the computer for later reading.

I also thank Charlie for posting the info on the report. _

BK,
I just re-read the section of the report you are referring to. I agree that scour holes existed on each side of the structure, but I did not see where they were connected. I would anticipate that should a scour develop completley beneath the structure failure of the structure would likely occur.

You are correct in that cars and other debris were deposited in the area to help control the scour, i have no idea how effective those measures were.

I have seen solid boulders larger than pick-up trucks deposited in the Mississippi River during LOW FLOW conditions. In order to place the rock in the correct location, it was placed upstream of its final location.

The Mississippi is certainly more powerful and complex than most realize.

[Bandwagon King]

_ BK,
I just re-read the section of the report you are referring to. I agree that scour holes existed on each side of the structure, but I did not see where they were connected. I would anticipate that should a scour develop completley beneath the structure failure of the structure would likely occur.

You are correct in that cars and other debris were deposited in the area to help control the scour, i have no idea how effective those measures were.

I have seen solid boulders larger than pick-up trucks deposited in the Mississippi River during LOW FLOW conditions. In order to place the rock in the correct location, it was placed upstream of its final location.

The Mississippi is certainly more powerful and complex than most realize. _

Ok. I'm gonna ask another one of "those" questions. Why build a structure with an enormous total flow capacity when it can't be substained & can be undermined & destroyed ? Does anyone know why this structure was designed this way?