America's Achilles' heel: the Mississippi River's Old River Control Structure

By: Dr. Jeff Masters , 5:20 PM GMT on May 13, 2011

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America has an Achilles' heel. It lies on a quiet, unpopulated stretch of the Mississippi River in Louisiana, a few miles east of the tiny town of Simmesport. Rising up from the flat, wooded west flood plain of the Mississippi River tower four massive concrete and steel structures that would make a Pharaoh envious--the Army Corps' of Engineers greatest work, the billion-dollar Old River Control Structure. This marvel of modern civil engineering has, for fifty years, done what many thought impossible--impose man's will on the Mississippi River. Mark Twain, who captained a Mississippi river boat for many years, wrote in his book Life on the Mississippi, "ten thousand river commissions, with the mines of the world at their back, cannot tame that lawless stream, cannot curb it or define it, cannot say to it "Go here," or Go there, and make it obey; cannot save a shore which it has sentenced; cannot bar its path with an obstruction which it will not tear down, dance over, and laugh at." The great river wants to carve a new path to the Gulf of Mexico; only the Old River Control Structure keeps it at bay. Failure of the Old River Control Structure would be a severe blow to America's economy, interrupting a huge portion of our imports and exports that ship along the Mississippi River. Closure of the Mississippi to shipping would cost $295 million per day, said Gary LaGrange, executive director of the Port of New Orleans, during a news conference Thursday. The structure will receive its most severe test in its history in the coming two weeks, as the Mississippi River's greatest flood on record crests at a level never before seen.


Figure 1. Two views of the Mississippi River. Left: the meander paths of the Mississippi over time, as published in "Geological Investigation of the Alluvial Valley of the Lower Mississippi River" (Fisk, 1944). Right: The Army Corps of Engineers' view of Mississippi River peak flow rates during a maximum 1-in-500 year "Project Flood" (U.S. Army Corp of Engineers, 1958.) The places outlined in red are where the Corps has built flood control structures capable of diverting a portion of the Mississippi's flow.

A better path to the Gulf
The mighty Mississippi River keeps on rollin' along its final 300 miles to the Gulf of Mexico south of New Orleans--but unwillingly. There is a better way to the Gulf--150 miles shorter, and more than twice as steep. This path lies down the Atchafalaya River, which connects to the Mississippi at a point 45 miles north-northwest of Baton Rouge, 300 river miles from the Gulf of Mexico Delta. Each year, the path down the Atchafalaya grows more inviting. As the massive amounts of sediments the Mississippi carries--scoured from fully 41% of the U.S. land area--reach the Gulf of Mexico, the river's path grows longer. This forces it to dump large amounts of sediment hundreds of miles upstream, in order to build its bed higher and maintain the flow rates needed to flush such huge amounts of sediment to the sea. Thus the difference in elevation between the bed of the Mississippi and the Atchafalaya--currently 17 - 19 feet at typical flow rates of the rivers--grows ever steeper, and the path to the Gulf down the Atchafalaya more inviting. Floods like this year's great flood further increase the slope, as flood waters scour out the bed of the Atchafalaya. Without the Old River Control Structure, the Mississippi River would have carved a new path to the Gulf in the 1970s, leaving Baton Rouge and New Orleans stranded on a salt water estuary, with no fresh water to supply their people and industry.

History of the Old River Control Structure
The Mississippi River has been carving a path to the ocean since the time of the dinosaurs, always seeking the shortest and steepest route possible. Approximately once every 1000 years, the river jumps out of its banks and carves a new path. In John McPhee's fantastic essay, The Control of Nature, we learn:

The Mississippi's main channel of three thousand years ago is now the quiet water of Bayou Teche, which mimics the shape of the Mississippi. Along Bayou Teche, on the high ground of ancient natural levees, are Jeanerette, Breaux Bridge, Broussard, Olivier--arcuate strings of Cajun towns. Eight hundred years before the birth of Christ, the channel was captured from the east. It shifted abruptly and flowed in that direction for about a thousand years. In the second century a.d., it was captured again, and taken south, by the now unprepossessing Bayou Lafourche, which, by the year 1000, was losing its hegemony to the river's present course, through the region that would be known as Plaquemines. By the nineteen-fifties, the Mississippi River had advanced so far past New Orleans and out into the Gulf that it was about to shift again, and its offspring Atchafalaya was ready to receive it.

For the Mississippi to make such a change was completely natural, but in the interval since the last shift Europeans had settled beside the river, a nation had developed, and the nation could not afford nature. The consequences of the Atchafalaya's conquest of the Mississippi would include but not be limited to the demise of Baton Rouge and the virtual destruction of New Orleans. With its fresh water gone, its harbor a silt bar, its economy disconnected from inland commerce, New Orleans would turn into New Gomorrah. Moreover, there were so many big industries between the two cities that at night they made the river glow like a worm. As a result of settlement patterns, this reach of the Mississippi had long been known as "the German coast," and now, with B. F. Goodrich, E. I. du Pont, Union Carbide, Reynolds Metals, Shell, Mobil, Texaco, Exxon, Monsanto, Uniroyal, Georgia-Pacific, Hydrocarbon Industries, Vulcan Materials, Nalco Chemical, Freeport Chemical, Dow Chemical, Allied Chemical, Stauffer Chemical, Hooker Chemicals, Rubicon Chemicals, American Petrofina--with an infrastructural concentration equaled in few other places--it was often called "the American Ruhr." The industries were there because of the river. They had come for its navigational convenience and its fresh water. They would not, and could not, linger beside a tidal creek. For nature to take its course was simply unthinkable. The Sixth World War would do less damage to southern Louisiana. Nature, in this place, had become an enemy of the state.


The Atchafalaya steadily took more and more of the Mississippi's water to the Gulf of Mexico during the 20th Century, until by 1950, it had captured 30% of the great river's flow, becoming the 4th largest river in the U.S. by volume discharge. The Army Corps of Engineers stepped in, and in the late 1950s began construction of a massive structure that resembled a dam with gates to control the amount of water escaping from the Mississippi to the Atchafalaya. This "Low Sill Structure", completed in 1963, consisted of a dam with 11 gates, each 44 feet wide, that could be raised or lowered. The entire structure was 566 feet long. A companion "Overbank Structure" was built on dry land next to the Low Sill Structure, in order to control extreme water flows during major floods. The Overbank Structure had 73 bays, each 44 feet wide, and was 3,356 feet long. The total cost of the two structures: about $300 million.


Figure 2. Aerial view of the Mississippi River's Old River Control Structure, looking downstream (south.) Image credit: U.S. Army Corp of Engineers.

The flood of 1973: Old River Control Structure almost fails
For the first ten years after completion of the Old River Control Structure, no major floods tested it, leading the Army Corps to declare, "We harnessed it, straightened it, regularized it, shackled it." But in 1973, a series of heavy snowstorms in the Upper Midwest was followed by exceptionally heavy spring rains in the South. The Mighty Mississippi rose inexorably until the flow rate at the Old River Control Structure reached 2 million cubic feet per second--twenty times the flow of Niagara Falls--and stayed there for more almost three months. Turbulence from the unprecedented flows through the Low Sill Structure scoured the foundation and destroyed a 67-foot-high wing wall that guided water into the structure. Scour holes as big as a football field developed upstream, downstream, and underneath the structure, exposing 50 feet of the 90-foot long steel pilings supporting the structure. The structure began vibrating dangerously, so much so that it would slam open car doors of vehicles parking on top of Highway 15 that crosses over the top. Emergency repairs saved the structure, but it came every close to complete failure.

The flood of 1973 permanently damaged the Low Sill Structure, forcing the Corps to build additional structures to control future great floods. The first of these structures was the Auxilliary Control Structure. This 442-foot long structure, completed in 1986, consisted of six gates, each 62 feet wide, and cost $206 million to build. Joining the mix in the late 1980s was a 192-megawatt hydroelectric power plant, build at a cost of $520 million.


Figure 3. The flow of water in the Mississippi River as of Friday, May 13 (red line) has exceeded 2 million cubic feet per second, and was approaching the all-time record (dashed blue line.) Image credit: USACE.

The Old River Control Structure's greatest test: the flood of 2011
Flow rates of the Mississippi at the latitude of the Old River Control Structure are expected to exceed the all-time record on Saturday, giving the Old River Control Structure its greatest test since the flood of 1973. Since there are now four structures to control the flooding instead of just the two that existed in 1973, the Old River Control Structure should be able to handle a much greater flow of water. The flood of 2011 is not as large as the maximum 1-in-500 year "Project Flood" that the Old River Control Structure was designed to handle, and the Army Corps of Engineers has expressed confidence that the structure can handle the current flood. However, the system has never been tested in these conditions before. This is a dangerous flood, and very high water levels are expected for many weeks. Unexpected flaws in the design of the Old River Control Structure may give it a few percent chance of failure under these sorts of unprecedented conditions. While I expect that the Old River Control Structure will indeed hold back the great flood of 2011, we also need to be concerned about the levees on either side of the structure. The levees near Old River Control Structure range from 71 - 74 feet high, and the flood is expected to crest at 65.5 feet on May 22. This is, in theory, plenty of levee to handle such a flood, but levees subjected to long periods of pressure can and do fail sometimes, and the Corps has to be super-careful to keep all the levees under constant surveillance and quickly move to repair sand boils or piping problems that might develop. Any failure of a levee on the west bank of the Mississippi could allow the river to jump its banks permanently and carve a new path to the Gulf of Mexico. I'll say more about the potential costs of such an event in a future post.

According to the latest information from the Army Corps the Old River Control Structure is currently passing 624,000 cubic feet per second of water, which is 1% beyond what is intended in a maximum "Project Flood." The flow rate of the Mississippi at New Orleans is at 100% of the maximum Project Flood. These are dangerous flow rates, and makes it likely that the Army Corps will open the Morganza Spillway in the next few days to take pressure off of the Old River Control Structure and New Orleans levees. Neither can be allowed to fail. In theory, the Old River Control Structure can be operated at 140% of a Project Flood, since there are now four control structures instead of just the two that existed in 1973 (flows rates of 300,000 cfs, 350,000 cfs, 320,000 cfs, and 170,000 cfs can go through the Low Sill, Auxiliary, Overbank, and Hydroelectric structures, respectively.) Apparently, the Corps is considering this, as evidenced by their Scenario #3 images they posted yesterday. This is a risky proposition, as the Old River Control Structure would be pushed to its absolute limit in this scenario. It would seem a lower risk proposition to open the Morganza spillway to divert up to 600,000 cfs, unless there are concerns the Corps has they aren't telling us about.


Figure 4. Kayaking, anyone? The stilling basin downstream of the Low Sill Structure of the Old River Control Structure, as seen during major flood stage of the Mississippi River on May 10, 2011. The flow rate is 2 - 3 times that of Niagara Falls here. Video by Lee Alessi.

Recommended reading
John McPhee's fantastic essay, The Control of Nature

Jeff Masters

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The 30 day SOI index has tumbled bigtime as it was around positive 30 by mid April and now is down to positive 6.7. This is a sign that La Nina is almost gone.

Member Since: April 29, 2009 Posts: 75 Comments: 14321
It's Steve BTW... :) Didn't really think about my username, kinda funny.

Quoting aquak9:
wow charlotte-(poor thing, we know you're a guy now but we gotta call you charlotte) I could see all those dents in your car, that's a shame. I hope they can repair all that. Man that's rough.

Plaza- let's not talk total destruction, ok? :(
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wow charlotte-(poor thing, we know you're a guy now but we gotta call you charlotte) I could see all those dents in your car, that's a shame. I hope they can repair all that. Man that's rough.

Plaza- let's not talk total destruction, ok? :(
Member Since: August 13, 2005 Posts: 166 Comments: 26050
Quoting aquak9:
plaza- heh heh heh- your sense of humor is about as messed up as mine!


We haven't even got started yet on what we will have to say when some of this stuff comes to fruition!!

Keep that photo of the guy with the digger by the pool cos it will be interesting to compare the 'before,' and 'after' photos if they open that floodgate. I saw boulders 3 foot across washed miles downstream when the water only came up 12 feet. The current is unbelievable if it gets a run start.

The big problem as I said earlier is if the back eddies get hold of the banks they can rip them to bits in minutes,from downstream,up, even on the plains as the water rises to the center of the flow and can be feet higher than the edges, amazing to watch. Destruction Total.
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154. Skyepony (Mod)
More flood inspired music. I was surprised by the lyrics being 1927.

THE TERRIBLE MISSISSIPPI FLOOD by Arthur Fields 1927
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Right over that Huge Loop Current Warm Pool




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Hello all I now have windows phone HTC great little device trickky to type on
Member Since: July 15, 2006 Posts: 174 Comments: 54360
Quoting Ivanhater:
18z GFS

That would be a scary set up for Florida if it was October.
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Hey Guys! I wanted to repost the hail video from yesterday. Made the actual video just a touch wider, and I'm also posting a damage video. Mostly minor stuff, but for anyone who is interested.

HAIL VIDEO:



DAMAGE VIDEO:

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plaza- heh heh heh- your sense of humor is about as messed up as mine!
Member Since: August 13, 2005 Posts: 166 Comments: 26050
Hey y'all with you tonight keeping an eye on things.
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DAVID GRUNFELD / THE TIMES-PICAYUNE With the Atchafalaya River in the background, Maxiam Doucet builds a levee around his house on River Ridge Road in Butte LaRose, LA. Wednesday May 11, 2011 in preparation for the onslaught of water from the Morganza Spillway. If the spillway is opened, the small community can expect water ranging from 5 to 25 feet.
Member Since: August 13, 2005 Posts: 166 Comments: 26050
Quoting:-141. aquak9

Its going to be a long summer on the east coast of Japan, by the time they get into their paper suits they will have run out of their time allocation and so will have to be rushed out of the area by the swat squad to be hosed down.
assuming the swat squad can get in and out in 30 seconds they will only be able to do 6 shifts in the year before they need to be replaced, the suited guys will of course never get to build the walls as they will always be waiting for their next years allocation of 3 minutes.
Meanwhile the fairly regular 6/7+ quakes will be causing all sorts of problems to the reactor containment vessels which now of course have become sieves. Back in the 'experts,' quarters the top brains will also have to think of what to do with the assorted debris that is glowing green and probably still littering the zone.
Maybe they should go the whole hog!! and nuke the place?
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I found it, pat - -Did not realize a barge would run aground a'fore hitting a levee, suppose that is some consolation.

three feet to the top, eh? man that is scary-looking.
Member Since: August 13, 2005 Posts: 166 Comments: 26050
Quoting xcool:
18z GFS showing tropical storm but w'e need more model support ;0


I only want to see the ECMWF join GFS and that is sufficient for me to believe something may develop.
Member Since: April 29, 2009 Posts: 75 Comments: 14321
Member Since: July 15, 2006 Posts: 174 Comments: 54360
ok pat, I've seen that guy before, big player for levees dot org. If he feels comfy, well then I suppose that's a little reassuring.

Lost the cam link- can't find it, ya wanna post that cam link again?

Nea- how long you think it'll take to build this (joke of) a protection system at fukushima, with workers only working 2-3 minute shifts? I'm gonna need some WD-40 for m'eyeballs, they rollin' so hard...
Member Since: August 13, 2005 Posts: 166 Comments: 26050
Member Since: July 15, 2006 Posts: 174 Comments: 54360
Just to interject after the 6.0 quake in Costa Rica we now have just got a 6.2 on the coast of Japan about where the nuclear mess is. USGS
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Quoting xcool:
18z GFS showing tropical storm but w'e need more model support ;0


I've seen it. Not only that, it's bringing some decent precip into Cuba and parts of Extreme S FL (1-2 inches near Homestead, almost 3 in parts of Cuba). So I guess 'Arlene' may wind up a drought-buster for Florida if the model plays out. We will see.
Member Since: May 15, 2009 Posts: 419 Comments: 679
I hope this Guy is NOT proved wrong aquak9
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Quoting CenLaGal:


The MS River does not drain the West Coast or the Rockies. The major concerns being ignored are the Arkansas, White and Ohio River systems. The White River is incredibly backed up and flooding parts of I-40 across central Arkansas.

Well, much of the eastern slope of the Rockies between central Colorado and the Canadian border drains into the Missouri, which in turn drains into the Mississippi. But I think the question he was asking was whether an early monsoonal flow was a harbinger of heavier rains elsewhere. At least that's how I interpreted it....
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Looks that way from the High angle,but it is 3 ft from most of the top there.

Spookie still.

The Levees Are Way Wide and a Barge would ride up usually,,now a Large Tanker is more Likely,,but still may run aground before breeching a Levee.

That was the specific questions answered on one Local Network here @ 6pm news
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134. xcool
Hurrykane welcome..
Member Since: September 26, 2009 Posts: 2 Comments: 15684
pat- if you're still here- I'm looking at the cam you posted on the first page, WAY back on the blog. Ok, that thing is like a bathtub about to pour over the edges.

Now, what about the barges? I mean, it's gotta be hard to control those barges with all the extra water. What are the chances of one of those barges getting away, and hitting a levee? Seems like I read an article on nola dotcom a coupla days ago, nola has laws about errant barges ("we sink'm") but I don't see much mention of the dangers of the continued barge traffic under such dangerous water heights.

anyone?
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130. xcool
18z GFS showing tropical storm but w'e need more model support ;0
Member Since: September 26, 2009 Posts: 2 Comments: 15684
.
Member Since: August 21, 2008 Posts: 0 Comments: 7574
Quoting RastaSteve:


You should these storms building here in C FL. We have a juiced up skyline right now.


Yeah I was in the Orlando area for much of today, I drove through one of those cells. The rain was very heavy and lots and lots of lighting. Good old Florida sea breeze storms!

The NWS said the PWAT would only be around 1.3 today and continuing that low into tomorrow but they should know better because the meso analysis shows PW's between 1.6 and 1.9 across Florida with locally around 2 inches or so near the sea breeze convergence. It also appears that should continue this weekend with decent coverage of scattered sea breeze activity.

They always downplay sea breeze storms in May just because its May and its usually dry. But just because that's true, they shouldn't be afraid to forecast higher chances of storms when there needs to be.

The forecast for low chances of storms this weekend I believe will be wrong. I'm not saying there will be numerous storms but I do expect decent coverage of scattered heavy storms, a few of which could be severe due to s strong LI, high cape and steep lapse rates. Moisture will be higher than forecast this weekend I expect just like today.


Even though the moisture will be higher than expected, we still won't be seeing the classic widespread 2 inch plus PWAT that we see with our classic sea breeze soaker pattern. But still enough to produce some scattered storms with the sea breeze moisture convergence and high instability.
Member Since: August 21, 2008 Posts: 0 Comments: 7574
Quoting iahishome:
Hmm, a little surprise to me... Monsoonal moisture started to flare for the first time this year in the Mountains and Deserts of Southern California today...

I think it's a little early though I haven't checked the history... Does this have any implications for the gulf and/or Mississippi Valley?


The MS River does not drain the West Coast or the Rockies. The major concerns being ignored are the Arkansas, White and Ohio River systems. The White River is incredibly backed up and flooding parts of I-40 across central Arkansas.
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Quoting BahaHurican:
Afternoon all...

Is this the latest forecast map?????



Just wanted to remind all that hurricane season starts in either 2 or 18 days, depending on ur basin.... LOL


Love the 'Illinois has it too easy storm'. The other paths may actually have some close historic basis to them. My kind of humor...thanks.
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Magnitude 6.0 - COSTA RICA
2011 May 13 22:47:55 UTC



* Details
* Maps

Earthquake Details

* This event has been reviewed by a seismologist.

Magnitude 6.0
Date-Time

* Friday, May 13, 2011 at 22:47:55 UTC
* Friday, May 13, 2011 at 04:47:55 PM at epicenter

Location 10.105°N, 84.261°W
Depth 70 km (43.5 miles)
Region COSTA RICA
Distances

* 25 km (16 miles) WNW (303°) from SAN JOSE, Costa Rica
* 126 km (78 miles) SSE (153°) from San Carlos, Nicaragua
* 137 km (85 miles) W (275°) from Limon, Costa Rica

Location Uncertainty horizontal +/- 16.5 km (10.3 miles); depth +/- 8.8 km (5.5 miles)
Parameters NST=376, Nph=381, Dmin=20 km, Rmss=1.23 sec, Gp=115°,
M-type=regional moment magnitude (Mw), Version=9
Source

* U.S. Geological Survey, National Earthquake Information Center:
World Data Center for Seismology, Denver

Event ID usc0003et0
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Costa Rica just got a 6.0 quake acording to USGS.

No more info at the moment.
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18z GFS

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Quoting:-80. Neapolitan

So in that drawl which we are so accustomed too:-
''It never rains but it pours,''
Thanks Neo for you comments on the Japanese real world as the rest of the world sees it.What a hell of a mess they have got themselves into this time round, 50 feet down will no doubt be below see level, bed rock! might be interesting to run a few tests on the effects of seismic shocks on all that lot if they ever get it built. highly improbable anyway.

Back to the US main drainage system:-
To consider this kind of problem it really has to be got into perspective and that is the problem, as no member of the public has ever tried to get the redirection of the Mississippi into perspective before!
What we have seen in Japan and other regions is not even on the scale of what will happen when/if the Mississippi deviates from its present course? This is GRAVE if it happens and could affect the entire Western global economy, its taking out the entire industrial ribbon development of the central southern US, whats more it could happen at the worst possible time as the hurricane season might just play a bit of an encore to all this.
I sincerely hope they have got all their timings right on the relief gates and channels, you don't get 2 chances with 2,million+cubic feet a second!
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TP's Bob Marshall explains the good, bad and ugly for oysters

Posted on Thursday, May 12, 2011 4:42PM
The Times-Picayune's Outdoors editor Bob Marshall explains what it means for oysters with the opening of the Bonnet Carre spillway and the introduction of vast amounts of fresh water into Lakes Pontchartrain and Borgne and the marshes east of the Mississippi River.
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A quick note on the value of river traffic. A grain train car carries about 3 trucks worth of grain. State of Washington flyer on the grain train In a conversation I had this morning with a friend who transports wood chips, he stated that one barge is about 100 trucks. On the Columbia river there are often 9 barges per tug, or about 900 trucks or 300 train cars. Our current transportation system cannot handle the loss of transportation on either the Mississippi or Columbia rivers.

Edit - the average tow is 15 barges, but can be up to 40. Link This link says that one jumbo barge is about 15 train cars and 60 trucks.
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There's 350 Bays in Bonnet Carre and its 100% open.

The Lake and ecosystem is changed for a year or so,,then returns to brackish and a better State ,history has shown.


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Sorry 350....typo
Member Since: February 27, 2010 Posts: 0 Comments: 1125
Pat, I didn't think they were going to open all 30 bays? Won't that put a lil too much into the lake?
Member Since: February 27, 2010 Posts: 0 Comments: 1125
Quoting beell:
Some had some very strong suspicions well before that.



Indeed, now the pig comes down the poke slowly and Morganza holds the keys seems.

Save for a New Madrid Slip,,or a Yucatan Spinner Cat 2 style comes up da river with a Surge.


May 23 crest NOLA

Id watch the 10 day, as 2011 seems bent on being furst in a lotta ways already
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I hope i don't get any nasty storms.. but do need the rain in the panhandle of FL..
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112. beell
From Dr. Masters's blog post today.

According to the latest information from the Army Corps the Old River Control Structure is currently passing 624,000 cubic feet per second of water, which is 1% beyond what is intended in a maximum "Project Flood.

The 1958 Project Design Flood document for ORCS is 620,000 cfs. 140% over PDF is 868,000 cfs.

Dr. Masters continues:

In theory, the Old River Control Structure can be operated at 140% of a Project Flood, since there are now four control structures instead of just the two that existed in 1973 (flows rates of 300,000 cfs, 350,000 cfs, 320,000 cfs, and 170,000 cfs can go through the Low Sill, Auxiliary, Overbank, and Hydroelectric structures, respectively.

I assume this represents each structure at 140% capacity and the total flow through ORCS would be 1,140,000 cfs. If not, and these figures represent 100% for each structure, overall total would be 1,596,000 cfs.

868,000, 1,140,000, or 1,596,000 cfs?

Almost failure was around 2,000,000 cfs according to Dr. Masters.

...The Mighty Mississippi rose inexorably until the flow rate at the Old River Control Structure reached 2 million cubic feet per second...

Member Since: September 11, 2007 Posts: 143 Comments: 16729
Quoting IKE:
Come on rain...just a tad further east without dissipating and I'm in business....woohoo!




Fill er up. Based on where you are in relation to the heavier cells you may get as little as 1/4" or as much as 1" IMO
Member Since: March 8, 2011 Posts: 1 Comments: 804
110. beell
Some had some very strong suspicions well before that.
Member Since: September 11, 2007 Posts: 143 Comments: 16729
Well most knew dat since Weds night here.

Also Bonnet Carre Now 100% opened..all 350 bays

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Hmm, a little surprise to me... Monsoonal moisture started to flare for the first time this year in the Mountains and Deserts of Southern California today...

I think it's a little early though I haven't checked the history... Does this have any implications for the gulf and/or Mississippi Valley?
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.