Floods can come from multiple sources. Be it a hurricane, failed dam, or overflowing river, this disaster can move quickly and sometimes with little warning. It’s important to know how to keep your family and belongings safe during such an event. A little preparation and time spent now can put your mind at ease when a disaster is looming! Before we dive right in, here’s something you should know about flooding.
Types of Floods
A flood is simply an event where water overflows a natural area and covers normally dry places. In general, there are two types. Flash and River flooding. Flash floods are more common in dry areas where the soil can’t absorb a lot of moisture. The water then rapidly runs off the surface resulting in a torrent of rapidly moving water. River Flooding is simply when a river overflows its banks due to excessive water, a situation made worse if barriers such as a levee or dam break as well.
Flooding can also occur in coastal areas from weather such as hurricanes, extreme high tides, and storm surges. This means that flooding can occur both in the city and the rural areas. An example of this was during July 2021, where both China and Germany suffered devastating floods in urban and rural areas.
What Causes a Flood?
There can be many causes for a flood ranging from man-made to natural. A flood can be caused by heavy rain, severe weather (such as a hurricane), dam failure, geography (low-lying areas), and melting snow. Living next to a river, dam, on the coast, or in a low-lying area puts you at risk for flooding.
When is Flood Season?
There is no specific flood season. Generally, from spring to fall is considered a heightened risk for floods. Any time there is a large amount of rain in a short period, flooding can occur. Man-made and natural disasters can also cause flooding outside of those months. For example, the collapse of a dam or levee can cause a flood. A natural disaster, such as a tsunami, can also cause flooding on a massive and devastating scale.
Are Floods Predictable?
In general, floods are predictable in the short term. Using existing maps and examining low-lying areas, it can be determined where high-risk areas for flooding are and the size of certain floodplains. When there is a large amount of rainfall over a short time, flood warnings are sent out to general areas that could experience flooding.
Can Floods Be Prevented?
Floods can be prevented through a variety of mitigation methods. Creating adequate drainage systems, natural or artificial, can prevent a buildup of floodwater. Reinforcing the banks of rivers, creating dams, levees, and floodwalls can also either stop or redirect floodwaters. Sandbags are a widely-used emergency measure to create an impromptu wall to stop water from reaching an area.
What Is a 100-Year Flood?
A 100-year flood is a flood that, based on past data, occurs once every 100 years. That doesn’t mean it can’t occur multiple times in the same year. It simply means that a flood of that size has a 1% chance of happening this year. It’s a ‘best guess’ when dealing with larger floods such as 500-year floods, and so forth. While unlikely, it is possible to have three ‘100-year floods’ in one year.
What To Do If Living In a Flood Plain Or At-Risk Location?
Like other disasters, preparing for a flood requires having a basic gathering of supplies in case of an evacuation. A basic supply list is a good idea to be prepared for the unexpected, floods included.
For a flood, there are a few important steps to take:
- Be aware of your risk for a flood.
- Look into your local maps (available at https://msc.fema.gov/portal/home) tosee if your home is at risk for flooding from a nearby river. If you live next to a flowing river, or even a dried-up one, there’s a good chance you live in a floodplain (A floodplain is an area next to a river that is prone to flooding).
- Read through the FEMA flood map to understand the risk of a flood in your area.
*Tips: How to read a FEMA flood map?
The flood maps available on FEMA’s website (https://msc.fema.gov/portal/home) are color-coded to indicate the risk of a flood in your area. The legend on the map indicates areas that have a higher percentage (per year) of flooding due to rainfall, potential levee failure. Other pieces of information include distance of the at-risk locations, areas with reduced flood levels due to levees, and potential future flood conditions. You can type in your specific zip code or address to locate the flood map for your area.
2. Make sure you can access the roof of your house (if you have an attic, make sure it is not closed off. There needs to be accessibleto the roof to avoid being trapped.)
3. Have multiple evacuation routes
Other important steps include purchasing flood insurance, storing valuables in water-tight containers, and knowing the flood risk for your specific area. More specific are listed on the United States government website. (Ready.gov).
Your basic supply list will likely be similar to that of hurricane or wildfire preparedness:
Grab-and-go supplies include:
Three-day supply of non-perishable food and three gallons of water per person
Map marked with at least two evacuation routes including meet-up locations if separated
Prescriptions or special medications such as high cholesterol medication, anti-seizure prescriptions, insulin, or thyroid medication
Change of clothing
Extra eyeglasses or contact lenses
An extra set of car keys, credit cards, cash or traveler’s checks
First aid kit including cold compresses and burn cream
Battery-powered weather radio and extra batteries
Portable Jackery units such as the 240, 300, or 500 power station to charge both phones and radios.
Sanitation supplies including heavy gloves (for sorting items on returning)
Copies of important documents (house deeds, photos, birth certificates, passports, etc.)
What To Do During And After a Flood?
If a flood warning or alert is issued over phone or radio, seek shelter immediately! Only six inches of moving water can sweep a person off their feet, and a foot of water can lift a vehicle. Do not try to wade through the water or drive through it.
If you can take steps immediately before the flood, do the following.
- Put grab-and-go supplies into your car if evacuation is likely.
- Turn off power to your home if possible (and you aren’t standing in water to do so)
- Unplug ground-level appliances
When an evacuation is ordered, immediately leave.
If standing water is visibly rising and you can’t evacuate completely, immediately get to the highest point you can. Do not go into an attic unless there is access to a roof!
Stay cautious if your home has been flooded, only return home when authorities signal that it is safe to do so. Due to the damage, a flood can cause, there may be dangerous power lines down, raw sewage leaking, and no plumbing available for a time.
Keep the power turning off at your home before entering. Do not turn on the power until a licensed electrician can inspect your home and ensure it is safe. Wear heavy gloves when sorting through items. Any items that have been immersed in water are likely not able to be saved for this reason. Wearing respiratory protection is also advised, as there will likely be large amounts of mold and mildew. Children, along with individuals who have allergies or sensitivities should not spend a long time in areas that smell of mold and mildew.
Floods are destructive disasters to both man-made and natural areas. Floodwaters can destroy homes, roads, bridges, and essential infrastructure. It can also destroy local animal habitats in a variety of ways. The rapidly moving water can wash away soil and sediment, physically removing areas, trees as well as possessions, contaminate homes to make them unlivable. It is often heavily contaminated with sewage and chemicals, polluting existing rivers, low-lying areas which may cause a die-off of wildlife in the affected area, and drastically change the landscape.