[Robert A Cook PE]

Yes, apparently the Red River and Atch. were "joined" by the early Corps of Engineers flood-control/shipping improvement changes so they could get the Red River open to shipping traffic towards Ark and East Texas.

That changed the Atch. flow, and helped the (previously minor) Atch. combine with/drain off the Missip's flow in a short cut around NOLA>

Then, to fix that shortcut, the Corps built extra dikes/locks to re-divert the Missip back towards NOLA. It's kind of confusing, but the net effect was to try to "cut off"/undivert the "natural" movement of the Missp. It really doesn't want to go in that big bend towards Lake P. any more.

[oceanagirl]

Thank you for the information. It is very, very interesting.

And thanks to all of you providing information on the flood situation in New Orleans and environs.