All about floods
Floods are one of the most common natural disasters causing loss of life. They occur in almost every corner of the Earth, and in many places they happen every year. In this text, we have gathered all the information you need to know about floods. We will talk about where and when to expect them, and what to do before, during, and after the water level rises.
H.V McKay Massey Harris, Factory Flood, Sunshine, Victoria, 1946. Photo: Museums Victoria / Unsplash
Causes of flooding
It’s important to know your enemy, and floods have several faces. Knowing the possible causes of rising waters will help you understand when you need to be alert and keep a close eye on the weather and the news. Here are the most common causes:
- Heavy or prolonged rainfall. Flooding occurs when rain doesn’t have time to soak into the ground, and lakes and riverbeds can’t accommodate the incoming water.
- Snowmelt. Flooding will occur if there is a lot of snow, or if it melts too quickly. And if the riverbed is blocked by ice floes and dense snow, ‘jams’ and ‘blockages’ will appear. In this case, the flooding will be even stronger and more rapid.
- Tsunami. This is a huge wave formed by underwater earthquakes and landslides. After hitting the shore, a tsunami does not recede like ordinary waves, but continues to move up to several kilometers inland.
- Wind surges. Strong and steady winds can create currents and move water. These currents ‘push’ water onto coastal areas, or ‘clog’ river channels in large bays.
- Dam and levee breaches. The rise of water can be rapid, and the flood will become a major destructive force.
Where to expect flooding
It is clear that a heavy downpour or snowmelt will not automatically lead to flooding in every situation or every place. To assess the risks, it is important to know the climate and topography of the place where you live or are planning to visit. Here is a rough list of the places most prone to flooding:
- Large or mountainous river valleys
- The shores of oceans and open seas
- Places where tropical cyclones make landfall
- Large and elongated bays
- Areas downstream from large dams
- Any areas that have been flooded in the past (this information can be easily found on the internet)
If you are in one of these places, or have them in the area where you live or are visiting, it is highly recommended that you take some time and read more detailed information on this topic. It can include: evacuation routes, property insurance, and special home layout options.
Emergency suitcase
If you live in an area with a high risk of flooding or other natural disasters, we recommend putting together a ‘go bag’. This is a small bag that you pack ahead of time, and store in an easily accessible place. In case of danger, you can grab it and evacuate without thinking about anything else. A ‘go bag’, or emergency suitcase, usually contains:
- Basic documents. If the original is always at home, you can keep it right in the suitcase. For other documents, put photocopies in the bag.
- A bank card linked to your main account, and some cash.
- Medicine that you need, and basic first aid supplies, including bandages, tourniquets, antiseptic ointment/spray, and so on. You can also add burn cream, antihistamines, remedies for intestinal disorders, and other medicines that may prove important in different situations.
- Copies of flat and car keys
- Personal hygiene products
- A supply of water and food for a day or two
- A notebook with a pencil
- A change of underwear, and a set of simple clothes
- A charged external battery or power bank for your phone or other electronics
In a flood, what you do depends on when you start to act. You may have received a warning and evacuation instructions before the water level started to rise. Or you could wake up to a siren blaring, and see water already flowing through the streets. Let’s look at some of the different potential cases.
Situation 1: Flooding is expected within a few hours
If you regularly check the weather forecast and local news, you will almost certainly know about the risk of flooding. And you’ll have plenty of time to get it right.
First of all, find out from the internet / radio / TV what actions the authorities recommend. Are you located in an area that could be flooded? Is it possible to leave by private transport? Are evacuations organized? Plan your route and pack the necessary items. Switch off the gas and electricity when you leave your home.
If you are evacuating on your own, your main goal is to get as high and as far away from the body of water as possible. If there is enough time before the flooding starts, contact relatives and other people close to you to see if they need help. But please don’t pile up a lot of things to do, and make sure you don’t have to run away from the rushing water like you see in disaster films. It is better to bide your time in a safe place than to risk your life.
Situation 2: Flooding is just beginning
In this case, you will do the same things as situation 1, but faster, and throw away everything unnecessary. If you can’t find something, don’t take it. If you can’t get evacuation information—act on your own. Throw away all the things that can slow you down. Thankfully, smartphones allow you to clarify the route, and call your loved ones when you are already on the go.
Situation 3: The water has already risen
In this case, the most important rule is to stay out of the water. Electricity can run through it, due to underwater damaged wires and power lines. Or you can underestimate its depth, and the speed of the current. Trying to cross or swim across rising water is like jumping out of a window during a fire. It is a last-ditch attempt to escape in a desperate situation that often ends badly.
Before entering the water on foot or in a vehicle, you must be 100 percent sure that it is safe. Photo: Saikiran Kesari / Unsplash
When you can no longer leave your home, climb to the upper floors, or if necessary, the roof. If you have time, board up windows and doors, and be sure to shut off the gas and water, and move valuables upstairs. Hang brightly colored cloth/clothes out of windows so you can be seen when it is time for you to evacuate.
Flooded house. Photo: Wes Warren / Unsplash
If you are outdoors and there are no buildings nearby, climb on any object that is more or less stable, which will keep you out of contact with the water. If you do find yourself in the water, don’t try to fight the current in an attempt to swim somewhere. Grab onto the nearest object that can keep you on the surface (a floating log or piece of wood, a barrel, whatever you can find) and wait for the water to recede. Your main goal is to stay upright for as long as possible.
After the flood
When the water starts to recede, it still pays to be on your guard. Here are the basic rules to follow after a flood:
- Do not return to your home until you have received permission from the authorities.
- When you return to your home, make sure it is not in a state of disrepair.
- Have damaged electricity, gas and water supplies repaired by someone who is a licensed professional.
- Minimize contact with items that have come into contact with water, and especially don’t eat dirty food. Chances are, many items that cannot be washed or have not maintained refrigeration/freezing temperatures will have to be thrown away.
- Contact the authorities and your insurance company to get information about payouts. Keep in mind that not all insurance covers all aspects of flooding.
We sincerely hope that you will not need this information, but we recommend that you take it seriously. If there is a risk of flooding in your area, take an evening and think about what you can do in advance and in case of danger. It could save your life one day.
Text: Eugenio Monti, a meteorologist and a climatologist
Cover photo: Wes Warren / Unsplash
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