Quick Dam: While this only works with lower levels of water, it could buy you precious time in your house during an evacuation or when trying to fortify your place. Have several yards of it ready to go as soon as the emergency horns sound.
Life Vests: Another important item that comes in many different forms. It's suggested you get the ones that have pockets and belts built in so you can store more safety items with you.
Radio: More storms could be coming and more dams could be breaking. You'll only know this if you have word from the outside world. Make sure your radio is waterproof, like this submarine radio, and pack extra batteries.
Pick Axe: A must have. It can help you clear rubble to a possible escape, be used for climbing to safety and can fight off cave zombies. Those guys are no joke.