Flash Flood Safety
Flash floods are a weather-related event that can cause significant damage to property, as well as loss of life. Being aware of weather conditions is an important part of staying safe when out of doors.
What Are Flash Floods?
A flash flood is one which occurs within a short time following a major rainfall. A number of factors come into play to create the conditions which lead to this type of flooding, including:
- Intensity of the rainfall
- How long the rain lasts
- Soil conditions
- Type of ground cover in the area
In most cases, a flash flood is caused by heavy thunderstorm activity or repeated thunderstorms in the same geographic area. They can also be triggered by the heavy rains which accompany tropical storms and hurricanes.
A flash flood may occur a few minutes or several hours after the rainfall. During the event, water may suddenly rise 30 feet or more. The moving water can also trigger a mudslide. The flood has the potential to uproot trees, move boulders and damage or destroy bridges and buildings.
Power of Flood Waters
The waters of a flood are immensely powerful. A person who is on foot and trying to move through a flooded area can be swept off his or her feet in only six inches of water. Once the water rises to the two-foot level, it is high enough to float a vehicle.
Tips to Stay Safe During a Flash Flood
- Be aware of local weather conditions before you head out. If you are traveling over land, check the forecast for your route and your destination. A thunderstorm watch in effect indicates that conditions are favorable for severe weather. The National Weather Service's Storm Prediction Centertracks activity and advises the public when a storm watch is in effect.
- Heavy rain over several hours or steady rain over a few days may trigger a flash flood. The spring thaw may add enough water to an area to create flooding as well.
- When the water level in rivers and streams rises quickly, the buildup may cause flooding in low-lying areas. Children have a fascination with water and should be told not to play near streams, drainage ditches or storm drains.
- If you are driving and come to a part of the road that has been flooded, the best (and safest) course of action is to turn around and drive back in the other direction. There is no way to accurately predict how deep the water is, and a car can be taken and pulled along with the flood waters at a relatively low depth.
- According to the National Oceanic and Atmospheric Administration (NOAA), more than 50 percent of people killed in a flash flood are in cars. Once the vehicle starts to float, it is at the mercy of the flood waters and is at a high risk of being pushed along sideways. At that point, the car may roll over and trap the occupants inside.
- Leave a stalled car and seek higher ground immediately. In this situation, staying with the vehicle is not the safer choice, even if leaving means getting soaked.
- Do not attempt to outrun a flash flood; the water can move much quicker than you can. Instead, focus your attention on getting to higher ground.
- If a flash flood watch has been issued for your area, it means that heavy precipitation may cause flooding. A warning means that flooding is imminent or is in progress. Stay alert and be ready to move out of the area immediately if a warning is issued.
Educating yourself about flash flood safety issues before an event occurs will help you make good choices if you are faced with a sudden rush of water. The best way to avoid a catastrophe is to stay away from flooded areas and seek out higher ground right away in this type of emergency.