Oh don't get me wrong, restoring the natural flooding cycle of the floodplain would be hugely beneficial to long term crop production from the area.

What the thread has been referring to is a summer where flooding ruins crop production for that year and how devastating that would be to our food supplies. It only takes 1 winter for people without food to starve.

Okay, gotcha. But even in '93 farmers managed to grow a crop on the floodplain. Taking out the levees & allowing snowmelt to renew the floodplain might preclude winter wheat and delay working the fields some years, but it wouldn't eliminate an entire growing season's crop. The occasional short-term detriment to agriculture would be enormously offset by the long-term benefit.