Flooding: America’s #1 Disaster | Floods are the most common natural disasters and can be the most destructive. Any place on Earth where rain falls is vulnerable to flooding.
A flood occurs when water overflows or encapsulates land that’s normally dry. This can happen in many ways:
River flooding can occur at any time of the year.
The flooding occurs when water levels rise over the river banks. This is due to:
Coastal flooding is caused by:
This type of flooding is common in Charleston, SC, and Savannah, GA. They experience impacts from shallow coastal flooding several times a year because of coastal development and lower elevation.
A storm surge is an abnormal rise in water level in coastal areas. This is caused by forces generated from severe storm winds, waves, and low atmospheric pressure.
These types of storms are extremely dangerous, because it is capable of flooding large coastal areas.
Extreme flooding can occur in coastal areas particularly when storm surge coincides with normal high tide, resulting in storm tides reaching up to 20 feet or more in some cases.
A storm surge is often the greatest threat to life and property from a hurricane. Hurricane Katrina is a prime example of the damage and devastation that can be caused by surge. At least 1500 persons lost their lives during Katrina and many of those deaths occurred directly, or indirectly, as a result of storm surge.
Inland flooding occurs when:
Hurricane Floyd, aided by Tropical Storm Dennis, caused widespread severe flooding that caused the majority of the $3 to 6 billion in damage reported after those storms.
A flash flood is caused by heavy or excessive rainfall in a short period of time, generally less than six hours.
Flash floods are usually characterized by raging torrents after heavy rains that rip through river beds, urban streets, or mountain canyons sweeping everything before them. They can occur within minutes or a few hours of excessive rainfall. They can also occur even if no rain has fallen, for instance after a levee or dam has failed, or after a sudden release of water by a debris or ice jam.
Areas damaged by wildfires are known as burn scars and are particularly susceptible to flash floods and debris flows during rainstorms. Rainfall that is normally absorbed by vegetation can run off almost instantly, causing creeks and drainage areas to flood much earlier and with higher magnitude than normal.
Affected Area: Galveston, Texas Year: 1900 Fatalities: 8,000 Cost: $602.3 million
The National Weather Service predicted that the storm would land farther east. Warnings were ignored by many residents. There was to much destruction for the city to fully recover.
Affected Area: Lake Okeechobee, Florida Year: 1928 Fatalities: 2,500-3,000 Cost: $1.5 billion
Lake Okeechobee had a 5 ft mud dike that was constructed to hold back the lake. However, the structure gave way do to a tidal wave.
Affected Area: Johnstown, Pennsylvania Year: 1889 Fatalities: 2,209 Cost: $12.6 billion
After an extended period of heavy rain a dam burst. The flood was massive and marked as high as 89 feet above the river level. This was the first disaster that the American Red Cross was involved in.
According to National Geographic, in the United States, floods do about $6 billion worth of damage and kill about 140 people every year.
Contamination– Land and waters can contain hazardous materials such as: sharp debris, pesticides, fuel, and sewage. The water after a flood can become contaminated as well as contaminate the land by washing around and through soil.
Mold– Anywhere that moisture is or was present can cause mold to form. This causes another problem for property owners.
Power– Flooding can effect the power with some residents going without a power source for days.
Drinking Water– The drinking water supply could be contaminated. Therefore, if consumed could lead to leading to waterborne diseases like typhoid, hepatitis A, and cholera.
Destruction– Due to the strength of flood waters, peoples homes, businesses, and property can become damage or even destroyed. This leaves many people without a home as well as creates a huge financial burden.
There are many steps you and your family can take to help protect against a possible disaster. Check out our previous blog post, Prepare Before a Disaster Strikes to learn how to protect your home and your family.