If you were going to actually 'blow' the levees, the levees couldn't be easily repaired with sandbags. You would have just plain blown them the h3ll away.
The French quarter is near the English Turn.......Let's remind ourselves of the 1814 defeat of the British, and previous defeat of the French, as well as of Ante-bellum homes. All that came about prior to the levees, i.e., on land above the water. Strategically, these positions were/are defensible. If they're of historic value now, or, happen to be White, I really couldn't say, as I have never been there. But this bit of exploding levees is the stuff of pure, fiction--and racism in and of itself. The positions have to do with geography and topology.
I'm not aware of the French being defeated at New Orleans. They gave New Orleans and the part of Louisiana west of the Mississippi to Spain in 1763 to compensate Spain for losing Florida to the British. (The British had captured Cuba and Spain traded Florida for Cuba.)