What Is A Flash Flood?

Through the south of the USA, there are many natural disasters.

What Is A Flash Flood?

Although it is an absolutely beautiful land, it is just as prone to problematic weather as it is to sunny days. It just comes with the territory, unfortunately.

Some weather events are more common than others, like lightning storms and droughts, but there is one weather event that a lot of people around the south know very well and are rightly afraid of. These are flash floods.

There are some questions around flash floods though that people constantly ask, like: what is a flash flood? How is a flash flood different from a normal flood?

In this article, we seek to answer these questions and give you the lowdown on flash floods and how you can deal with them.

Flash Floods: What Are They?

A flash flood is an extreme weather event that occurs in or around low-lying regions or bodies of water, often near lakes, basins, rivers, streams, or washes.

It is the rapid rise of water into and around these areas that is incredibly disruptive and destructive to anything and anyone within these regions.

Another thing about flash floods is that they are incredibly quick, as this extreme level of flooding will happen within six hours of a significant rain-period.

They are usually caused by potent storms that unleash a heavy deluge of rainfall within a short period of time.

The difference between flash floods and normal floods is two-fold. The first is the timing, as normal floods can take days to reach their peak and are normally caused by moderate to heavy rainfall over a long period of time.

The second is that flash floods are far more physically dangerous in the moment to people, animals, objects, and vegetation.

Since a flash flood is more often a lot of water appearing in one go, it moves quickly and as one entity, often like a suddenly appearing river or lake.

This means that the fall weight of the water can push aside anything in its path, knock living things down and push them under the water for long periods, or simply reach a height so quickly that people are forced to swim for higher ground.

What Causes Flash Floods?

There are actually quite a few causes of flash floods in the modern day.

The most common one is – as we said earlier – intense rainfall over a short period of time, and this typically is most common after a period of no rain.

Storms can brew for some time if the conditions are right and no rain can mean that lots of rain is on the way, but it can also mean that the soil is completely dry (or is cement).

That means that when the rain does come, the soil may have become harder with a poor immediate absorption ability.

This will mean it cannot absorb the rainwater all at once and so the rain goes over the top, combining into a torrent that heads towards flat and low-lying land (basically down hill or into valleys).

If there continues to be dry, solid soil further along, then the water will continue to combine and pick up speed, thus becoming a flash flood.

What Is A Flash Flood?

Another cause of flash floods is actually the opposite to this, where there has been a lot of recent rain and the soil is completely saturated.

When an intense rainfall happens over a short time in this scenario, the soil cannot absorb any more water and so the water travels further along to low-lying land, creating the same torrent from different circumstances.

Finally, the last cause of flash floods is a man-made one.

When we build structures like dams and reservoirs, but do not check them regularly or build them properly, then that is an accident waiting to happen.

At some point, something will break and the structure holding a huge amount of water back will buckle under the pressure, eventually causing a massive flash flood.

How To Prepare For A Flash Flood

If you live in an area where floods or flash floods are common, then that is unfortunate, but again you can’t fight nature.

However, you can prepare yourself and your home for the potential of flooding. The first is to listen to weather reports regularly, especially during storm season.

Even though flash floods cannot be predicted, you can make an estimated guess based on the recent weather and the knowledge of your home region, whether a flood will come.

The second is to buy a couple of things. These are sandbags and some kind of boat, even an inflatable one.

Sandbags are one of the best flood defenses, and the hessian bag itself is really cheap. As such, you just have to buy the bag if you live near the beach or the bag and sand if you don’t.

Then, when you are worried about a flood, you can put them round your home to stop the water getting in.

You will need to buy a boat as well. It doesn’t have to be fancy or expensive, just sturdy – again, an inflatable will work.

The flood will likely be contaminated and there is always the possibility of an alligator or a dangerous river fish being in the water, and you do not want to deal with that if you need to flee.

Finally, you need a good supply of freshwater and an emergency Duffel bag full of food, medical supplies, a radio, extra clothes, a radio, batteries, and a survival blanket.

Water is always shut off during a flood and the waters are contaminated, while all the stores will be closed, and you may be stuck for days without any food.

As such, you need some equipment to last a few days, just in case.


Flash floods are one of the scariest natural disasters, because it is so hard to predict them.

However, with a little time and some general preparation, you can still make it easier when these waters come cascading into your life.

Tim Roth
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