A Billion dollars and a re-built Old River Control Structure says it won't happen anytime soon. It did almost happen about 30 years ago, but quick work saved the old Old River Control Structure from a washout.
There is also the Morganza spillway and the Bonnet Carre spillway to regulate the flow on the lower river.
Sounds good. Must be quite a system!!
Nature has a way of putting hubris on display.
They need to build the city on higher ground. There is such ground between the Mississippi and the Atchafalaya.
Start by moving the new city there - the surviving manufacturing and port facilities will still be close to the new metropolitan area.
Then, build a canal and an inland dredged port parallel to the Atchafalaya, and control structure to keep enough water coming down the existing channel for the canal, along with locks between the canal and the existing channel.
That way, when the river does jump, we'll be ready. It'll take 15 years, but IMO it's an insurance policy against the hazards that hang over the current locations and would ensure continued navigation up the Mississippi.