Flood Facts Sometimes a river receives a lot of extra water, either from lots of rain or other natural disasters. When this happens, the water overflows from its normal path in the river bed and possibly onto dry land. This is called a flood. See the fact file below for more information about floods. Floods occur because of heavy rains, a river overflowing, a dam or levy breaking, a tsunami, or melting snow. The word “flood” comes from an old English word that means “a flowing of water, river, or sea.” Floods occur even in the desert. Rapidly moving water can be dangerous. It is so powerful it can carry a car, house, tree, or person away. Two feet of water can float a large vehicle, even a bus. Some states makes citizens reimburse the cost of their rescue when they drive into flooded areas. Some places call these IDIOT laws. 66 percent of flood deaths occur in vehicles, and most happen when drivers make the fatal mistake of trying to navigate through flood waters. Just 6 inches of rapidly moving flood water has the strength to knock a person down. Flooding poses tremendous danger to both people and property. Since 1900, floods have taken more than 10,000 lives in the United States. The Big Thompson Flood in Colorado in 1976, killed 140 people . 95% of those killed in this flash flood tried to outrun the waters along their path rather than climbing rocks or going uphill to higher grounds. Floods can kill people, animals and destroy homes, businesses and even farmland. The great Mississippi River Flood of 1993 covered an area 500 miles long and 200 miles wide. More than 50,000 homes were damaged, and 12,000 miles of farmland was destroyed.