Must be true, it's all the talk at DU.
Water flows downhill due to gravity. The low-lying neighborhoods are located right next to the levees so they would naturally fill with water first when a levee breaks. Eventually if the leak goes on long enough, the water level rises until the higher neighborhoods begin taking on water too.
It's called gravity. Obviously a concept that DU and the race warlords cannot grasp. No one ever pumped water into any neighborhood...duh. All pump outlets go into the canals.