He guys, haven't been on in a while since i've been so busy. Someone told me there was a good thread here that is right up my ally. I'll throw in my $.02, and parden me if I restate some things b/c I just read 4+ pages of stuff, but I think there is some things that are not quite correct unless i'm mis-understanding what some of you are saying.
They will start opening Bonne Carre on Monday monring. It has not been officially decided if Morganza will be opened yet. That IS one huge decision, but that is what it was put there for. Morgan city is at a huge risk "if" they do, but there is a lot more protection than there was in 1973, and that actually goes for the whole system. The areas around Morgan City are what is really at risk. Once the water is past the protected areas, it starts flowing back up through the swamps and bayous through Stephensville and Amelia.
The reason it was opened in 1973 was to save the Low sill structure at Old River. It releived pressure on that structure. The Miss. will not try and re-route itself through the Atch. b/c of Morganza being opened, it actually is more of a risk if it isn't like in 1973. Morganza helps divert water away from Baton Rouge and New Orleans between the East Atch River levee and the East Atch. Basin protection levee. Then water will flow back up on the West side of the River once it gets past the river levees.
As far as blowing levees, everybody wants to jump on that rumor bandwagon and speculate where a levee will be blown, and lately i've heard some real off the wall places. This is how the system works, the Miss. flows through to the gulf from up north and 30% is diverted through the Atch. 70% staying in the Miss., if more than 1.25 Mill cfs (cubic feet per second) is flowing past Bonnet Carre than it is opened. Once there is more than 1.5 Mill cfs flowing past Morganza is when there needs to be a decision on opening it or not. It can divert about 600,000 cfs and the Old river system about 620,000 cfs. Once those levels are reached is when there is talk about blowing a levee, but not just anywhere and it woulnd't flood anything outside the West Protection levees, the levee that would be blown is a fuse plug levee that lies between the West Atch. River levee and West Atch. Basin Protection levee in Simmsport. In my personal opinion if that were needed, there would be a guy building a really big boat and loading animals on it somewhere!
I hope I Explained that clearly. I was typing fast and there is way too much stuff going through this head right now.