Mississippi State University Weather

The Power of Water: Flash Floods & Flooding

When we think of water, it’s easy to picture a serene beach or an endless ocean. After all, most of our planet is covered with water. However, Mother Nature shows us its wrath when it comes to flash flooding and flooding events. In fact, based on a 30 year average, flooding has caused a higher number of fatalities per year compared to tornadoes and hurricanes. How much water does it take to cause harm? You might be surprised!

What is a Flood?

First and foremost, it’s important to know what exactly a flood is. According to the National Weather Service, a flood is any high flow, overflow, or inundation by water which causes or threatens damage. There aren’t specific criteria for defining a flood because it depends on the location where the flooding is a threat. Depending on nearby rivers, topography, and soil types, different amounts of rainfall or melted snowpack will cause flooding at different locations.

Flash flooding is a flood that occurs in an extremely short amount of time, usually within six hours of the initial event (rainfall, etc.). The National Weather Service defines it as a rapid or extreme flow of high water into a normally dry area, or a rapid water level rise in a stream or creek above a predetermined flood level. Both flash flood and flood watches and warnings can be issued when a flooding event is likely to take place. A watch is issued when conditions are favorable for a flood to develop with the given environment, while a warning indicates a flood or flash flood is imminent and immediate action should be taken to stay safe.

A Little Water Goes a Long Way

It doesn’t take much water to cause significant damage to structures or to simply threaten our safety which is one reason why flooding can be so devastating. Six inches of slow moving water is enough to not only sweep people off of their feet, but also cause people to lose control of their vehicles. Two feet of water can completely move some vehicles. Even sound structures, like houses, aren’t completely safe from flooding. This past summer, I traveled to Johnson County, KY where four inches of rain fell during the span of one hour. One home was literally swept off of its foundation, and several mobile homes were completely destroyed due to the rising water from a nearby creek. Tragically, four people passed away in the flood.flood1

Mobile home destruction in Johnson County, KY from flash flooding on July 13, 2015. Photo taken by Taylor Graham

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A truck swept away in flood waters in South Carolina on October 5, 2015. Portions of the state received over 20 inches of rain during the span of approximately three days. Photo courtesy of CNN. 

Preparation is the Best Medicine

Flash floods can strike with very little warning because they typically happen so quickly. Because they happen on such a short notice, being prepared before a flash flood strikes is the key to staying safe during an emergency situation. Here are a few tips to keep in mind when it comes to a flooding event.

  • Have an emergency kit prepared with bottled water, food, and a first aid kit. This is not only helpful for flooding events, but other emergencies as well.
  • Know your home insurance plan. Many insurance policies do not cover flooding.
  • Talk with your family about making an evacuation plan in case flooding occurs.
  • Be aware of nearby rivers and creeks that may quickly rise during heavy rain and snow melt.
  • NEVER drive through standing water or a flooded road. It’s difficult to know how deep the standing water is, and it’s extremely easy to lose control of your vehicle.
  • Seek higher ground if a flooding is an immediate threat to your home or safety.

Flooding approximately causes seven billion dollars in property damage each year in the United States. Moreover, it’s the second most common natural disaster in the United States, and it can happen in all 50 states. Don’t become a victim by underestimating the power of water!

-Taylor Graham

 

Citations

“Glossary – NOAA’s National Weather Service.” National Weather Service, 25 June 2009. Web. 05 Oct. 2015. <http://w1.weather.gov/glossary/index.php?letter=f>.

“NOAA Knows…Floods.” (2013): 1-2. National Oceanic Atmospheric Administration, Jan. 2013. Web. 5 Oct. 2015. <http://www.noaa.gov/factsheets/new%20version/floods_2.pdf>.

“Weather Fatalities.” Natural Hazard Statistics. National Weather Service, 3 Aug. 2015. Web. 5 Oct. 2015. <http://www.nws.noaa.gov/om/hazstats.shtml>.

Yan, Holly, and Ray Sanchez. “South Carolina Flooding: More Devastation Possible – CNN.com.” CNN. Cable News Network, 06 Oct. 2015. Web. 06 Oct. 2015. <http://www.cnn.com/2015/10/06/us/south-carolina-flooding/>.