Well, the U.S. Army Corps of Engineers maintains the levee system for both the Atchafalaya and Mississippi Rivers. They are the same cats tasked with keeping New Orleans dry during torrential flooding rains and rising water (read Katrina).

They work pretty hard on maintaining this system over the last several decades and I'm not exactly sure who fumbled the ball during the hurricanes of 2005- I'm guessing everyone did in one way or another...

The government obviously has a keen interest in protecting the busiest port in the U.S.- the port of South Louisiana. If the Miss. river changes course (a matter of when and not if) New Orleans and Baton Rouge would cease to be major ports.

The Wetlands Research Center in Lafayette has indicated that a shift of the Miss. River to the Atchafalaya River would have a devastating economic impact on our state. I've heard some people indicate that once the shift occurred New Iberia would be the new New Orleans as a port city (well, what is left of New Iberia anyway...)