Severe flooding can contaminate local water supplies, and prolonged power outages can interfere with the city's water purification and pumping systems. Thus, having bottled drinking water is a wise precaution. Some people even suggest filling your bathtub with fresh water for washing and flushing the toilet if the city water supply is threatened. Flashlights with fresh batteries. In case of a power outage.
Candles also can be useful.
Radio with fresh batteries. This will allow you to hear any emergency announcements during a power loss. Very high winds can break windows. Some Houston residents recommend putting strips of tape over large windows to minimize the spread of broken glass should the window blow in. Driving can be very dangerous when streets are flooded.