I have four 5-gallon water bladders filled and ready to go with the emergency gear. If we need to bug out they go in the car with the other stuff. I rotate it about once a year; it's never had any taste issues during that time. The water in my town is particularly good so I don't worry about bacterial contamination as long as the containers stay closed.

We have at least three or four cases of bottled water rotated regularly. I keep a case in each car as well. Finally there's the water heater.