That's because we (and those who live on the ridge) live in the oldest part of the city and on the rim of the deep, wide soup bowl formed by the burbs.
I can be dry as a bone day after a storm that leaves 3-5 feet standing in homes out in Metairie, Jefferson or down in the Parish.
Threw a hissy fit when my cab took an hour to come day after a storm in '95 only to arrive downtown and realize I was one of three folks to show in our entire office. The burbs were under water.
This is not to say the dog and I won't be paddling to a friend's third floor warehouse studio if The Big One comes but that's the calculated chance you take ... as opposed to the sure-lose situation that is building or buying on a flood plain.