Water is the primary source of life and agriculture, and a vital component of travel and trade. Consequently, civilization developed around available sources of abundant water such as rivers, lakes, and, of course, oceans.
Even today, more than 90% of the world’s population lives within ten miles of a large body of water. In many areas, flooding is a regular occurrence, usually a result of seasonal storms or expected snowmelt.
These areas have generally adapted to flooding by placing buildings on raised supports or constructing levees, dikes, and other embankments. In other locations, however, where floods are not expected on a regular basis, they can be deadly.
Read on to find out how you can maximize your chances of surviving a flood.
What is a Flood?
The legal definition of a flood, used by disaster relief agencies and insurance companies, is “any water in contact with the ground that has risen higher than its normal level or grade.” Another important component is its movement.
A yard or street that has collected standing water from unusually heavy rains is not flooded, according to the legal definition. If that same yard or street is under water because a nearby dam burst and the waters rushed out to cover it, then it has been flooded.
It seems to be splitting hairs—after all, water damage is water damage if you’re a homeowner having to repair and replace belongings—but it is a distinction that makes it important to check with your insurance company about exactly what will be covered, and under which circumstances.
What Causes Flood?
Floods can manifest in a number of different ways, but they are all caused by the same mechanism: an unusually high volume of water is suddenly introduced into an area that cannot disperse it effectively.
The water may come from a storm, higher than average snowmelt, or the collapse of a natural or artificial embankment. The ground may be too saturated to absorb any extra water or may be too dry or hard-packed to allow water to penetrate.
Rivers can jump their banks when too much water is introduced upstream, and even underground waters can burst onto the surface if their volume exceeds their carrying capacity.
High winds can push walls of water in front of them (called a “storm surge”). This is most often seen in front of hurricanes, but can also happen along large lakes and big rivers.
Mountainous areas and deserts can experience “flash floods,” in which tall walls of water build up very quickly and move fast. Six-foot walls are not uncommon, and narrow canyons can force the water even higher.
As with earthquakes and tornadoes, the best preparation for a flash flood is to be ready well in advance, as you may only have minutes to get to safety.
How to Prepare for a Flood
Communities that experience regular, seasonal flooding build upwards to allow clearance, establish protective embankments, or both. On an individual level, homeowners should find out from their insurance company how likely a flood is for the area, and buy or build accordingly.
This may include raising the house up, extensive waterproofing of any area below expected water levels, building retaining walls, etc. For areas that are under threat of flash floods, sandbags are usually created (or stockpiled) to erect temporary embankments.
One of the dangers of floods is that if any defenses are breached upstream, it can cause a cascade of failures downstream. Not only are levees (for example) suddenly straining against even more water pressure, the debris carried by the flood acts as a battering ram, further weakening the structure.
This is one of the reasons the damage was so extensive in New Orleans during Hurricane Katrina.
How to Stay Safe During a Flood
In general, the best way to stay safe is to be aware of bad weather and have an evacuation plan in place. If a flood is expected, emergency bulletins will be issued.
Make sure your evacuation route is not within the affected area. Remember, the earlier you leave, the more you will be able to secure against damage.
Whether you are on foot or in a vehicle, if you come across a flooded area while evacuating, DO NOT try to cross it. One inch of moving water can knock an adult off of their feet, and it only takes four to six inches of water to move a car.
Statistically, almost half of all flood deaths are from occupied vehicles being taken by flood waters. If your car is trapped by flood waters, abandon it and head to higher ground as quickly as possible (don’t forget your survival kit!).
Even if you are a great swimmer, flood waters contain debris, may be contaminated by sewage or worse, and can have electrical hazards from ruptured power lines. They can even contain terrified animals such as rats, cats, or snakes that will attack and climb on you in their desperation to survive, so stay out of the water!
Tips on What to Do If You can’t Evacuate
If you are unable to leave the immediate area, your best chance is to get to an official shelter or climb to as high an altitude as possible in or on top of a solid structure.
Extra precautions may need to be taken in cases where the flooding is caused by a storm, and high winds are also a factor. If you are sheltering within your home, shut off the main power breaker (only if it is safe to do so!) to prevent shorts and fires.
How to face the aftermath of the Disaster
Surviving the initial rush of water is only half of the goal. Depending on the severity of the flood, recovery efforts can take weeks to months to years.
There are parts of New Orleans that are still damaged (if not abandoned entirely) after Katrina landed in 2005, such as this former amusement park.
Prepping for the long-term is the key, here. All of your stockpiled food should be canned or stored in waterproof containers.
Have manual can openers, as it may take a while to restore power in your area. Have lots of clean drinking water on hand, as well as multiple ways to treat large quantities of water. The biggest risk of post-flood is contamination.
Waters may be contaminated with sewage, medical or toxic waste, heavy metals, pesticides and other poisons, and corpses. If you sustain any injuries in the flood, get a tetanus shot as soon as possible.
Remove all damaged-beyond-repair items from the home, including drywall and insulation. Dry your home as quickly as possible to prevent mold and fungus from forming.
Any salvageable items that come into contact with flood waters must be cleaned and decontaminated before use (except fresh food, which must be discarded). A mild bleach solution and hot water is usually sufficient to kill bacteria and prevent mold and fungus.
Your local water company will also need to do extensive testing and maintenance before water service can be restored. If you get your water from a well, you may be personally responsible for having it tested.
Avoid using the electrical grid until cleared to do so, both broadly and within your own home, and be aware of the risk of ruptured gas mains. You may not be able to use open flames for cooking or heat.
We hope that you have found this post helpful. Come back tomorrow, when we will be discussing movies and television shows with a survival theme. We’ll see you then!