Well duh.... I think that virtually 100% of it came from Lake Pontchartrain, no? I say 'virtually 100%' (purely as a technicality) because with the storm surge occurring on the Gulf, I suppose that the direction of water may have been temporarily reversed going through the Rigolets so some of the water in Lake Pontchartrain could theoretically have come from the Gulf.... oh and of course some of the water came in the form of rainfall brought in by the hurricane itself.... there, I think that just about forms the total water from ALL sources that could have potentially flooded New Orleans, no? There is of course a question as to the degree of localized storm surge on Lake Pontchartrain...all one has to do is look at the storm path to see that New Orleans was significantly to the west of the eye ....http://en.wikipedia.org/wiki/Hurricane_Katrina
As for your second question, what is the relevance of that? What on earth could you have been smoking to read into my post a suggestion that the Corps of Engineers had any responsibility for evacuation? Sheeesh....it has absolutely nothing to do with the issue raised... which to remind you had to do with why and how New Orleans ended up under water. Which brings this to your turn.... what exactly do you believe the failure mechanism to have been that caused New Orleans to be flooded? What exactly do you disagree with in the link that I provided in Post 26?
I disagree with the idea that any of this debacle was the fault of the Corps of Engineers. Bloodsucking pols decided that pet projects were more important than a proper levee system, and bloodsucking pols are happy when people blame the Corps.