Actually, it is best if you are near the river or the lake. The closer, the better. Because, you see, the city is on what is called an alluvial flood plain. Near the bodies of water that overflowed in geologic time frames, the land built up. So anything within a couple of blocks of the river or the lake shore fared reasonably well. It was the center of the city that took on a lot of water, and that was caused by poor levee construction, not anything else.
I believe that if you don't mind a long commute, your best bets north of Lake Ponchartrain are all north of Interstate 12. However, that makes your drive time a serious issue. With gas prices subject to heavy fluctuation, and with lots of water to cross or go around if you live north of the lake, you might do better to look on the south shore. Which gives you unincorporated Jefferson Parish on the east bank, plus the cities of Harahan and Kenner, and New Orleans itself.
East of the city was more badly flooded than the city itself. West and south of the city were hit-and-miss. Go find a flood map online. For starters, search www.nola.com, which is a pretty good site with lots of links to such things.