Mississippi River flooding in New Orleans area could be massive if Morganza spillway stays closed

The Times-Picayune ^ | 5.11.11 | Mark Schleifstein

[trumandogz]

If the Morganza Floodway is not opened to funnel 300,000 cubic feet per second of water from the Mississippi River into the Atchafalaya River basin, the additional water could cause levees to fail along the river from Morganza to Plaquemines Parish, including all of the New Orleans area, resulting in as much as 25 feet of floodwater, according to a map provided to state officials by the Army Corps of Engineers on Tuesday.

[muawiyah]

There are lots of other folks in the lower Delta living out around all over the place. They'll tell you blowing up levees in Missouri helps just Cairo, but it also protects the entire agricultural area in the Illinois part of the Delta.

One more time, the Delta is the main fancy bean growing area in the world. Mexico has a contract on about 90% of the bean crop there. This is their meat.

By protecting the Delta Bean Crop we keep 35 million Mexicans in Mexico and I think that is an excellent idea, don't you?!

[DManA]

You have obviously thought about this much more thoroughly than I have. Many trade offs to be considered.

[Jeff Chandler]

how hard is it to control something like water?

I can't believe you posted that.

[ßuddaßudd]

Does she have an album release soon?

[EGPWS]

The mayor is Mitch Landrieu, baby brother to Mary.

Oh, a Louisiana co-owner.

I just wondered if that "whip crack" Ray Nagin was still there.

[dfwgator]

Louisiana - Half under water, the other half under indictment.

[Charles Martel]

It sounds hard hearted I know, but, you either let the towns flood and it affects them more or less alone. Or you flood farm land and it affects everyone. With the possibility of a food shortages.

In the context of this thread, it's not just cities like New Orleans that have to be weighed against farmland. You have to factor in the majority of the Lower Mississippi River Industrial Corridor (including the Shell Norco refinery) as well.

[ErnBatavia]

Cairo is two-thirds black. End of case.

[CajunConservative]

Nagin has been busy writing his memoirs.

http://www.nola.com/politics/index.ssf/2011/05/former_new_orleans_mayor_ray_n_3.html

[MsLady]

Why? You missed the context and my point of what I said. They are trying to control the flow of water. It's impossible.

I suppose but, how hard is it to control something like water? The end results can be good or bad.

[Senator Pardek]

Speak for yourself. Like anyplace - some whine and some contribute. P.S. - did I show you my back tattoos?

[tbw2]

Wouldn’t that solve a lot of New Orleans’ problems with flooding if the river isn’t there?

[HereInTheHeartland]

“The will have to open the Morganza. “

I haven't followed this closely.
What happens when this is opened?

Thanks

[trumandogz]

Some water will be diverted from the river down into the Atchafalaya which would raise the water level is a great deal of swamp land and flood some farms and a few small towns.

If you do not open the Morganza water will top or breach the Mississippi River levees at or around New Orleans.

[centurion316]

Without the river, a great deal of the commerce that keeps NO going would be gone. The French Quarter isn’t enough to sustain the city.

[Paul R.]

I happened to check the report for Paducah a little while ago: There are STILL about 1.1 million cfs flowing past Paducah (Ohio River) alone. The flow and levels are starting to drop fairly quickly now, though. Local news this evening reported 1 million gallons per second being released from KY Dam (gallons per sec. is of course a “bigger” sounding number.)

In the 1927 flood, the Mississippi below Memphis was 60 miles wide. 145 levees broke. I suspect that flood was worse than this 2011 flood, from the standpoint of water in the system, but it spread out more. If it had been “contained” in 1927 the way it is in 2011, the levels would have been even higher.

[Paul R.]

An awful lot of places in the Paducah / Western KY / Southern IL area flooded this time, and quite a bit more would have if that Birds Point levee had not been blown... Paducah came very close to having their new Convention and Expo Centers flood, among many other things. Downtown Paducah is “safer” from the river than Cairo primarily because they have a better floodwall, and more $$ to keep it in good shape. Before that floodwall was built, Paducah was nearly wiped out by the 1937 flood:

http://en.wikipedia.org/wiki/Ohio_River_flood_of_1937

Paducah IS for the most part a thriving small city, but that’s not because it’s inherently safer from the river. It’s been better run than Cairo, among other things, and I do NOT mean that as a racial comment: The “better run” easily goes back to a time when Cairo was run by whites.

[Paul R.]

That’s not actually true, in the case of the Birds Point levee that was blown. If you look at the maps provided by the Corps of Engineers, an enormous area, much bigger than the New Madrid Floodway, including a big chunk of SEMO farmland, was at risk, if that floodway was not operated. Many other towns / parts of towns in Western KY and Southern IL were also at risk. The MEDIA, to make it a jucier story, turned it into a bogus “Cairo vs. the farmers” issue.

Now, that said, operating the floodway in MO is a pipsqueak (except for the actual levee blasts!), compared to opening up the Morganza. I am not sure how much farmland floods if the Morganza Floodway is not operated — probably quite a bit — but intentionally flooding an area with (I read somewhere) 25,000 people in it... Morgan City alone is 12,000 residents. Wow, what a decision to have to make...

Keep in mind though that again, this is not just a “Floodway area” vs. one city issue. Much more than New Orleans is at risk, and that risk includes the “Old River Control Structure” that presently prevents the Mississippi River from changing course, as others here have discussed.

Wikipedia has some fairly good info.:

http://en.wikipedia.org/wiki/Morganza_Floodway

http://en.wikipedia.org/wiki/Old_River_Control_Structure

(Note: Both the above links also have a link to an article on the current flood, which article contains a significant amount of erronious and contradictory information.)

[Paul R.]

THIS article says 2500 residents (not 25,000) and 18,000 acres of crops would be affected by opening up the Morganza.

http://www.nola.com/weather/index.ssf/2011/05/mississippi_river_floodway_ope.html

Dang news media — hard to get accurate info., as usual...

[deport]

The spillway will be opened gradually as the River reaches the max point of flow. They will open gates as needed to keep it at the max point.

from the article:
Corps Maj. Gen. Michael Walsh, president of the Mississippi River Commission and commander of all corps districts along the river, has strongly hinted that he will approve opening the Morganza Floodway sometime between Friday and Tuesday. That’s when the rate of water moving past Red River Landing, across from the Louisiana State Prison at Angola, will reach 1.5 million cubic feet per second, which is the official trigger for opening the spillway.