Release it where? Where do you put it that doesn't drain back into the Mississippi accept at the Morganza Spillway to the Atchafalaya Basin?
Actually, releasing the water into the Morganza is a “lesser of two evils” plan, but it is the best option. Were it not, the levee system between Baton Rouge and New Orleans could be compromised, threatening many refineries and other petro-chem facilities - perhaps more than $100 billion in infrastructure.
The value of the infrastructure in the Atachafalaya Floodway is considerably less than the value of that along the river between Baton Rouge and New Orleans.
As far as opening the Morganza early, that would have little impact. In fact up until a couple of weeks ago, the water wasn’t even high enough in front of the spillway cause water flow.
The Old River Control complex already was flowing water from the Mississippi into the Atchafalaya.
And, IIRC, the Corps of Engineers can only operate the floodways until certain conditions are met, and those conditions are set by law and have been for many years.
The other spot is the Bonnet Carre spillway. The river flows into Lake Pontchartrain and then into the Gulf through the Rigolets.