2011 Mississippi River Spring Floods

[HelmutVII]

If you go here

http://www.stream.fs.fed.us/fishxing...s_Equation.htm

It will give you a brief description of Mannings Equation.

However, the fine print at the bottom says

"Under the assumption of uniform flow conditions the bottom slope is the same as the slope of the energy grade line and the water surface slope."

This is a BIG assumption and is not the flow conditions in the Mississippi at this time (nor at any time for that matter)

Also if you are familiar with applying the equation --"A", "R", and "n" are VARIABLE for any given cross section and engineering judgement must be used in applying the equation to a given station in a river. That's right "A" (area) is a variable because of scour.

If you go here

http://earthobservatory.nasa.gov/Nat...w.php?id=50690

you will see in the top image lots of deep blue along the Mississippi river basin. That deep blue is water. Compare that to the bottom image you can see that there is a ______ load of water STILL between Cairo Illinois and Memphis Tenn. Anybody want to guess where that water is going? The caption for those images is "lingering floods along the Mississippi". I would suspect that once that water decides to move there won't be much to stop it.

Anybody want to guess what kept that water up there? How about high water down stream (the crest). High water that is getting lower because we have crested down here. Because we have crested and the water is getting lower the energy grade (down here) is lower resulting in an increase in the slope of the energy grade line (The "S" in the Mannings equation). from here to up there. When "S" gets bigger so does "Q". "Q" can get higher without an corresponding increase in "A" (stage) if "S" gets high enough. Guess what ---"Q" is the determining factor in the operation of the Morganza spillway.

Because this is a hydrodynamic event we could be looking at fluctuating between an upstream control event to a downstream control event depending upon where you are along the river.

[Bandwagon King]

_ 9 hrs later? Sorry but you did not see the results on a chart from morganza in Morgan city nine hrs later. You are not seeing the results of morganza in Morgan city now. Or at most you started seeing that sometime today. Is that why you made the assumption that the atch. River and calumet were handling everything? Sorry but you're way off if that's the case.

That's not from any formulas or any education I have received, or any charts. that is pure fact.


igeaux.mobi _

That's not what I'm saying Big Ed. What I am saying is you can look at those charts & see distinct rises in the levels just like opening a choke on well on one platform & watching the rate go up on another platform 10 miles away 10 minutes later. I guarantee you I could show it to you & your mind would be blown. I can show you how an inch of rain that would fall in Missouri would make its way felt in Mississippi in less than 24 hours. The thing people need to realise is water is noncompressible & can send messages for miles down stream. These charts are unbelievable in what they can tell you. This is a fact.

I respect your work, but please don't tell me it's not so until you have taken the time to review them with someone who can read them.

[Boomer]

_ That's not what I'm saying Big Ed. What I am saying is you can look at those charts & see distinct rises in the levels just like opening a choke on well on one platform & watching the rate go up on another platform 10 miles away 10 minutes later. I guarantee you I could show it to you & your mind would be blown. I can show you how an inch of rain that would fall in Missouri would make its way felt in Mississippi in less than 24 hours. The thing people need to realise is water is noncompressible & can send messages for miles down stream. These charts are unbelievable in what they can tell you. This is a fact.

I respect your work, but please don't tell me it's not so until you have taken the time to review them with someone who can read them. _

Ya'll this is how GREAT inventions come about--the mingling of knowledge from different areas and then the combining of these to create something totally new and "MONEY MAKING"------Get together and check it our leaving the egos outside the meeting place!!!!!

[HelmutVII]

So why do they go through all the trouble to get gage readings in the river? Well I'll tell you.

1) You can't get a cross sectional area - "A" of the river without it. Something that is necessary in Mannings equation. Once you have the elevation of the water you can relate it to the bottom cross section and calculate "A".

2) The gage reading is used to measure potential energy. Once you adjust the gage reading to NAVD88 you can determine the difference in elevation from one station to the other. Each station is at a known river mile, so you know the distance between the stations. Knowing the elevation of the water combined with measuring the velocity of the river at the stations allows the calculation of the total energy (potential and kinetic) at each station. We can now determine the difference of these two values and knowing the distance between the stations allows us to calculate the energy slope "S" in Mannings equation.

3) The gage readings are published for maritime interests along the river. They need this for two main reasons---1 to see if there is enough water for them not to ground their vessel (not the case now) and --- 2 for them to determine how much horsepower they need for the weight of their tow. (they are lifting the weight of their tow upstream the difference in water surface elevation). That, in addition to the added velocity of the river, is why the Coast Guard required an increase in horsepower for tugs along the river.

If you go here

http://www.srh.noaa.gov/lmrfc/?n=lmr...oriverforecast

Look at the DIFFERENCE in water levels between Red River Landing at 66.2 and Baton Rouge at 44.2 or a 22 foot drop in a relatively short length of the river. I would suspect that the velocities and eddy currents in that stretch of the river are pretty high. Anybody want to guess why there have been TWO barge accidents at that location of the River in the last week? To not consider the affects of Kinetic energy on the river at this time is a big mistake.


While we are looking a gage readings go here again

http://www.srh.noaa.gov/lmrfc/?n=lmr...oriverforecast

and look at the 24 hour difference at Cape Girardeau and Thebes. Is that not an increase of 0.3' foot and 0.2 foot respectively? Could it be that the flood plains upstream of there are starting to release their water? Could we be having a mini crest coming down the river?

The plot thickens as we move to a different chapter of this story. .

[biged05]

_ That's not what I'm saying Big Ed. What I am saying is you can look at those charts & see distinct rises in the levels just like opening a choke on well on one platform & watching the rate go up on another platform 10 miles away 10 minutes later. I guarantee you I could show it to you & your mind would be blown. I can show you how an inch of rain that would fall in Missouri would make its way felt in Mississippi in less than 24 hours. The thing people need to realise is water is noncompressible & can send messages for miles down stream. These charts are unbelievable in what they can tell you. This is a fact.

I respect your work, but please don't tell me it's not so until you have taken the time to review them with someone who can read them. _

Then please clarify this statement..."I can tell you this. Every time they opened a gate in Morganza I could see it on the charts in Morgan City nine hours later like clock work. Now if those things aren't useful for gleening information I don't know what is."

There's no doubt in my mind when you open a choke you can see the result 10 miles away in 10 min. But please tell me the chart that you're looking at that shows indications of opening Morganza in Morgan city in 9 hrs, or tell me what you meant by that statement.

Again I appreciate your compliment on the work I do, but I can read charts and understand them, I just don't know of any that can show you what you're stating. Tell me what chart(s) you're looking at specifically, and I can go pull them up and compare them to what times the gates were opened. I have access to the exact times every gate was open and closed. (And just to clarify, gates are opened and closed on a daily basis while keeping the number that they need open. They distribute the flow thru the structure differently daily, but keep the same number of gates open)

[Bandwagon King]

_ Then please clarify this statement..."I can tell you this. Every time they opened a gate in Morganza I could see it on the charts in Morgan City nine hours later like clock work. Now if those things aren't useful for gleening information I don't know what is."

There's no doubt in my mind when you open a choke you can see the result 10 miles away in 10 min. But please tell me the chart that you're looking at that shows indications of opening Morganza in Morgan city in 9 hrs, or tell me what you meant by that statement.

Again I appreciate your compliment on the work I do, but I can read charts and understand them, I just don't know of any that can show you what you're stating. Tell me what chart(s) you're looking at specifically, and I can go pull them up and compare them to what times the gates were opened. I have access to the exact times every gate was open and closed. (And just to clarify, gates are opened and closed on a daily basis while keeping the number that they need open. They distribute the flow thru the structure differently daily, but keep the same number of gates open) _

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.

[jumboragncajun]

What I am saying is you can look at those charts & see distinct rises in the levels just like opening a choke on well on one platform & watching the rate go up on another platform 10 miles away 10 minutes later.

Open Channel is gravity driven. Not driven by pressure as the readings on a platform. This is not a platform as someone stated already. I thought we went through this.

I can show you how an inch of rain that would fall in Missouri would make its way felt in Mississippi in less than 24 hours.

That is simply 'Velocity'. Once you follow the lessons of HelumutVII and are familiar with the basic formula, you can manipulate the left side of it determine the average velocity.

I respect your work, but please don't tell me it's not so until you have taken the time to review them with someone who can read them. _

You have repeatedly stated how well the Corps is doing their job. repeatedly. Probably a dozen times or so. And I agree with you. So NOW, you saying that a professionally licensed engineer for the corps can't read a chart?

Do you honestly wonder why people insult you "95 ways till Sunday"?

[Bandwagon King]

_ So why do they go through all the trouble to get gage readings in the river? Well I'll tell you.

1) You can't get a cross sectional area - "A" of the river without it. Something that is necessary in Mannings equation. Once you have the elevation of the water you can relate it to the bottom cross section and calculate "A".

2) The gage reading is used to measure potential energy. Once you adjust the gage reading to NAVD88 you can determine the difference in elevation from one station to the other. Each station is at a known river mile, so you know the distance between the stations. Knowing the elevation of the water combined with measuring the velocity of the river at the stations allows the calculation of the total energy (potential and kinetic) at each station. We can now determine the difference of these two values and knowing the distance between the stations allows us to calculate the energy slope "S" in Mannings equation.

3) The gage readings are published for maritime interests along the river. They need this for two main reasons---1 to see if there is enough water for them not to ground their vessel (not the case now) and --- 2 for them to determine how much horsepower they need for the weight of their tow. (they are lifting the weight of their tow upstream the difference in water surface elevation). That, in addition to the added velocity of the river, is why the Coast Guard required an increase in horsepower for tugs along the river.

If you go here

http://www.srh.noaa.gov/lmrfc/?n=lmr...oriverforecast

Look at the DIFFERENCE in water levels between Red River Landing at 66.2 and Baton Rouge at 44.2 or a 22 foot drop in a relatively short length of the river. I would suspect that the velocities and eddy currents in that stretch of the river are pretty high. Anybody want to guess why there have been TWO barge accidents at that location of the River in the last week? To not consider the affects of Kinetic energy on the river at this time is a big mistake.


While we are looking a gage readings go here again

http://www.srh.noaa.gov/lmrfc/?n=lmr...oriverforecast

and look at the 24 hour difference at Cape Girardeau and Thebes. Is that not an increase of 0.3' foot and 0.2 foot respectively? Could it be that the flood plains upstream of there are starting to release their water? Could we be having a mini crest coming down the river?

The plot thickens as we move to a different chapter of this story. . _

If you are talking about what is going on way up river that is the result of rainfall this weekend. It will have an affect on levels, but by then I am suspecting the river down here will have told its own story. I understand you are a very smart man. I understand you have a brilliant mind. I am saying from the reception I have gotten here, considering I haven't been wrong, is pretty harsh. I am saying that I must be seeing something. Yet I have been laughed to scorn & this leads me to believe that the maximum amount of info in these charts is not being utilized. Most people would have told you guys to get screwed & signed off by now. This is real. It is a treasure trove of information. What if what I'm saying about the river sending signals days ahead of time is true ? I can prove what I'm talking about is true.

What if the hydraulic effect of the water difference is travelling faster than the water itself? What if you could take the signals that the river is sending downstream & use it refine your equations to the point that you could possibly predict within a couple of minutes & a couple of hundreths of a foot the exact levels of the crests down stream 500 miles & be at least 99% accurate?

Just think of the possibilities that are there. These charts are not just gauge level readings. They are story tellers & their story is non fiction.

[NewsCopy]

NEW ORLEANS – The Mississippi River's fickle flooding is testing the patience of residents, some of whom were returning to their homes after being driven away by the threat of rising water, while others are still being kept away as inspectors try to ...

The rest of the story

[Bandwagon King]

_ If you are talking about what is going on way up river that is the result of rainfall this weekend. It will have an affect on levels, but by then I am suspecting the river down here will have told its own story. I understand you are a very smart man. I understand you have a brilliant mind. I am saying from the reception I have gotten here, considering I haven't been wrong, is pretty harsh. I am saying that I must be seeing something. Yet I have been laughed to scorn & this leads me to believe that the maximum amount of info in these charts is not being utilized. Most people would have told you guys to get screwed & signed off by now. This is real. It is a treasure trove of information. What if what I'm saying about the river sending signals days ahead of time is true ? I can prove what I'm talking about is true.

What if the hydraulic effect of the water difference is travelling faster than the water itself? What if you could take the signals that the river is sending downstream & use it refine your equations to the point that you could possibly predict within a couple of minutes & a couple of hundreths of a foot the exact levels of the crests down stream 500 miles & be at least 99% accurate?

Just think of the possibilities that are there. These charts are not just gauge level readings. They are story tellers & their story is non fiction. _

At the risk of being a pain in the neck can someone tell me why the Atchafalaya appears to have crested in Simmsport & Melville & appears to be cresting in Krots Springs as I write?

Is that a possible indicator that the gates can start being closed at the Morganza?

[cajun_civil]

_ If it was flowing more than its design capacity, then the water was either going under over or around the calculated opening of the gates of the structure. I understand that you are saying that the calculated flow rates were above what it was designed to handle, however the given area of flow will only allow so much water through it. This will change slightly based upon the hydrostatic, hydraulic, or hydrodynamic head, "slightly", but once you are putting 10'X10' or 1000' X 1000' of solid fluid through a structure at a certain point you can't put anymore. That's it, cetu' fine'. I can't say I have seen the ORCS, although I have seen the power plant at Simmsport. I can say that structure is set up so that no more than a certain amount of water can flow through it no matter what. It appears as though it is about 30' thick of concrete & reenforced steel as I recall. _

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.

[Bandwagon King]

_ 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. _

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.