See my last post to Knitting_a_Conundrum.
If this guy is correct that is a huge problem. I've been assuming that many of the levees that protect the city are based on sea level assuming the Lake gets only so much higher (driven by storm surge).
If the River is allowed to backflow through the Industrial Canal then they have a real ongoing problem. Especially if the River comes up from Rita. MR GO is a relieve valve, I suppose. Time to go to the maps. My connection to the Maptech topo and chart server is down. Do you know levee heights besides the River ones?