I think you will see that most flood evacuation boats used by Fire/Rescue Services tend to be of the Jon/flat bottom style. They are stable, can operate with a low HP outboard engine (or even be paddled) can be used to load and transport family members/friends (think kids, older folks and pets) and limited supplies/home valuables with fewer issues then an inflatable, canoe or kayak. Since many flooding conditions result in contaminated water (sewage, petroleum, pesticides, etc.) using a stable flat bottom boat decreases your chances of having to enter the water, whether due to capsizing or simply loading the boat.

Keep in mind, we are talking flooding conditions not swiftwater and unless you have the training and proper equipment, never attempt to enter (swimming, fording or in a boat) water that is moving.

Pete