As asphalt- and concrete-covered surfaces expand and open spaces disappear at the edges of our metropolitan areas, it takes less rain to flood communities as water running over the pavement collects quickly and easily disrupts storm drain systems. Floods, once purely known as "acts of God" are being rapidly enhanced by the works of humans.
Those areas which are most at risk for floods include low-lying areas, coastal regions, and communities on rivers downstream from dams. Flood waters are extremely dangerous; a mere six inches of swiftly moving water can knock people off their feet. The safest thing to do during a flood is to evacuate and seek shelter on higher ground. It is important to know the safest route to a safe location.
In some regions of the world, flooding is caused by excessive rainfall, such as monsoons, while in other parts of the world, flooding can be caused outside of the rainy season when snow and ice being to melt in the mountains. That meltwater flows downstream, which can cause flooding.
Flooding is caused downstream from dams when reservoirs, which normally help to prevent downstream areas of rivers from flooding, are opened due to unusually high levels of precipitation to prevent the reservoir from overflowing the dam. Dam breaks are also a cause of catastrophic flooding.
Flood Zone Designations
Floods are often given designations as a "hundred year flood" or "twenty year flood," etc. The larger the "year," the larger the flood. But don't let these terms fool you, a "hundred year flood" does not mean that such a flood occurs once every 100 years; instead it means that there is a one in one-hundred (or 1%) chance of such a flood occurring in a given year. Two "one-hundred year floods" could occur a year apart or even a month apart -- it all depends on how much rain is falling or how quickly the snow melts. A "twenty-year flood" has a one in twenty (or 5%) chance of occurring in a particular year. A "five-hundred-year flood" has a one in 500 chance (0.2%) of occurring in any given year.
Flood Preparedness
In the United States, homeowners insurance does not cover flood damage. If you live in a flood zone or any low-lying area, you should consider purchasing insurance through the National Flood Insurance Program. Contact your local insurance agent for more details.You can be prepared for flooding and other disasters by assembling a disaster supplies kit. Take this kit with you if evacuating:
- A portable, battery-operated radio and extra batteries (know the appropriate radio station to listen to during a disaster).
- Flashlights and extra batteries.
- First aid kit and manual.
- Emergency food and water.
- Nonelectric can opener
- Essential and prescription medications.
- Cash and credit cards.
- Sturdy shoes.
- Extra clothes and bedding.
- Food and supplies for pets.
