blow the dikes move the buildings up away from the rivers and plant the bottom lands after the river lays fresh fertile soil on top of last years mulch. basically the way they used to treat the major rivers until we go the notion we could build walls to keep them in their channels
Yep, move the people out of the floodlands and let the river be wild. Restore the entire Mississippi watershed (get rid of most plow agriculture and use permaculture instead). Restore gallery forests (forests bordering the river).