2011 Mississippi River Spring Floods

[Zeebart21]

_ Z,

I crossed the basin the first week it opened, which happened to coincide with the 1973 opening of Morganza. If this one is like that, you will not believe the water level.. _

Vo, if you look closely, you can still see the water stains on the pilings when you cross Henderson swamp. Never thought Id see it that high again... maybe we will?

Z

[moorecajun]

_ How do levees finally give in---there was talk of the ones around LSUBR being vulnerable from the stress or dampness/wetness???? Who makes the final decision as to whether to blow a portion of a levee and where----This is so interesting and your knowledge so great of the situation!!! Thanks for your time and effort---Had I not changed my major muchos tiempos and after spending 13 straight years in college ---NO MAS!!!! Nice way to make a living!!! _

But didn't all that time and major changing make you more diverse! lol

[biged05]

Helmut,

You're doing a great job explaining all this stuff. Keep up the great work. I still don't have time to write anything up often, but I at least read the posts.

[Boomer]

_ Helmut,

You're doing a great job explaining all this stuff. Keep up the great work. I still don't have time to write anything up often, but I at least read the posts. _

$$$$$$$$$-I think there is some 'GREEN" in your posting---Since the Softball stadium is done ---get Frenchie or any of our photo dudes to get some great FPS for you (Flood photos) Then you trace the snowfall and other factors that have led to this along with a brief history of flooding of the Mississippi and get that in print---Now just watch all the crap happen and record it!!!! If I still had my old job I could have printed it for you---If you want, get Dr. Fun to get some human side issues and Johnny Boy as your Miss. reporter!!! Of course you mention most money from book sales would go to TAF ---Later you say that you mis-spoke and meant RCAF!!!!!!

[cjr3888]

Any way to look up the mean sea level for certain areas?

[CajunMarine81]

Gotta be global warming and W's fault.

igeaux.mobi

[Bandwagon King]

_ The conditions that are expected are an "upstream control" not a "downstream control" event. The level of the water in these areas is mostly controlled tide. Since there is water in the channels already, the excess capacity is that area of conveyance ABOVE the current water levels. (If a glass is half full then the excess capacity of the glass is the top half of the glass). Since the water level upstream is higher already, the increased conveyance would happen at a higher level. So anything that is at or below the current channel bottom levels would have little affect on the conveyance. (making the channel deeper is not the answer making the channel wider is, make a half full glass wider at the top).

Also since the water surface, is higher the slope of the water surface is higher causing an increase in velocity. If there is any debris in the river I would suspect that it would soon be flushed out. Not to say that it would not be replaced by more debris from upstream.

The thing that controls water flow in an open channel is not necessarily the slope of the bottom of the channel but the slope of the top of the water. (more specifically the slope of the Hydraulic Grade Line HGL. don't ask me to explain that in a message board as it is a 400 level course in Civil Engineering schools).

Bottom line, once the water gets that close to the Gulf (water surface elevation of zero) the water will seek that level through the line of least resistance (water is lazy) which is tide dependent not channel bottom dependent at this location.

That's the best I can do maybe somebody else can make a stab at a better explaination. _

If the volume of water flowing down from a higher elevation to a lower elevation was allowed to be relieved earlier by allowing the hydraulic force of the lower elevation to become 0 in counterforce, wouldn't that go a long way in allowing the upper level hydraulic force to relieve it's stress sooner & thereby allow for an earlier lower crest in river levels? All I know is south of any levees & within 5 miles of the mouth of the Atchafalaya river at the GOM the river has risen some 4' above normal levels. This is not simply due to above normal tides. If you drain 6" of water down a 3" pipe & you continue to do this more than the 3" pipe can handle the 6" pipe will become backed up even if your draining it straight down. I know that the Atchafalaya is no more than 1-2' deep for almost the whole width of the river & has a very shallow narrow ship channel, although it is twice as wide below Bayou Shane, as it is above Bayou Shane. This is helping cause the Atchafalaya to rise in Berwick & Morgan City right now, even though the Atchafalaya is really meant to handle the watershed from the Red & Ouachita rivers.

If the river rises in Berwick until the hydraulic force up river causes it to flow hard enough to push that water out, it causes Bayou Shane to back flow into Amelia & even up to Stephensville, thereby exasterbating an already dangerous situation.

Please correct me if I am wrong. But if not so, why are they going to sink a giant barge across Bayou Shane to try to keep lower Terrebonne parish from flooding? I am just saying that if you add up all the little things that could be done together, they add up to possible avoidance of a huge freaking mess.

I really believe that someone has done cost analysis of letting this type of occurance happen avery 40 years & finds it to be more cost effective to allow several thousand people to be totally wiped out, than to take a completely comprehensive view of flood control & hurricane protection.

No offense to the parties opining here. I have great respect for the corps of engineers.

[CajunRed]

When I first saw the Corps' Inundation Map, I thought I was misinterpreting what it was saying...as it was showing up to 15 feet in Henderson Lake ABOVE current levels.

Unfortunately, my interpretation was correct. The Corps' latest prediction for Butte la Rose is 29 feet...which will top the small interior levees that follow along the river. That means water levels in Henderson Lake will be only 4 or 5 feet below I-10. And many homes and camps along eithe road to Butte la Rose will be well under water. Even the rest stop facilities at I-10 will be flooded.

Guys...that is downright scary.

Thanks for the map. If I am reading correctly, it is showing Henderson Lake in "green"...which is 10 to 15 feet above current levels. Ouch! That would be very scary.

igeaux.mobi

igeaux.mobi

[HelmutVII]

_
I really believe that someone has done cost analysis of letting this type of occurance happen avery 40 years & finds it to be more cost effective to allow several thousand people to be totally wiped out, than to take a completely comprehensive view of flood control & hurricane protection.

No offense to the parties opining here. I have great respect for the corps of engineers.

Since a picture is worth 1000 words I will need to shoot some photographs to show you how it works. I will try to do that by tomorrow. Once you see the photos I think you will understand. Once I post the photos, I will then be able to explain a "thought experiment" to you.

[Boomer]

_ Since a picture is worth 1000 words I will need to shoot some photographs to show you how it works. I will try to do that by tomorrow. Once you see the photos I think you will understand. Once I post the photos, I will then be able to explain a "thought experiment" to you. _

How is the book coming along---I am serious!!!!!!! Make sure that T-Bine keeps all these forcasts --etc!!!!

[HelmutVII]

_ How is the book coming along---I am serious!!!!!!! Make sure that T-Bine keeps all these forcasts --etc!!!! _

I don't know about a book, but I'm thinking Randy Newman might be writing another song.

[cjr3888]

These are pictures I took at the Bayou Benoit Landing from the top of the levee. First picture is Sunday (low tide) and the next two are Wednesday (high tide). If we get the amount of water projected, it might reach the top but probably won't. I saw government trucks (USGS) parked out there today, which is never a good sign. At least they parks on the other side of the levee so the fisherman could park at the landing.