10 Facts About Floods
Author: Donna Conneely
Floods are defined as the sudden covering of normally dry land with water, usually from melting snow, burst dams, storm surge, or heavy rains. Floods can occur in any of the 50 states of the United States, and are the most common reason for a Declaration of Emergency announced by the President. Hurricanes almost always result in flooding disasters, and climate scientists believe that these massive storms will become more frequent and more destructive over the coming decades. As flooding becomes more frequent and more widespread, there will be floods in places that have rarely suffered this fate in the past. Today we take a look at some facts about floods, including a few that may be quite surprising.
Flood damage is rarely included in home or property insurance policies. Unfortunately, this very often comes as a surprise to the homeowner. To be covered for flooding, a special flood insurance policy must be purchased. In some areas, this policy can be prohibitively expensive or even not available at all!
Kingfisher, OK, August 19, 2007 — This red car was washed off the highway and it occupants had to be rescued when Tropical Storm Erin flooded the area. Marvin Nauman/FEMA photo
It does not take much water to carry off a vehicle. Even a bus can be swept away by as little as two feet of water! Every year drivers who are attempting to flee floods make the deadly decision to drive through shallow but fast-moving floodwater, only to be caught up in the flood with no control over the vehicle.
Floods can happen in places where not a drop of rain is falling. The most common scenario is a placid river that suddenly becomes a death trap when a flash flood appears from unseen heavy rain upstream. These flash floods can present a wall of water up to 20’ high, with absolutely no warning!
Natural flooding is essential for farming. We all learned in grade school about the Fertile Triangle and the cradle of civilization, and that this annual flooding from the Tigris and Euphrates was necessary for the deposit of rich new soil for agriculture. Today farmers around the world still depend on floods for the same reason, and have adopted seasonal migrations to avoid the damage while reaping the benefits of this regular flooding.
The world’s most deadly flooding took place in the year 1931, along the Yellow River in China. Between 1-4 million people lost their lives during a series of floods that year.
The most common source of flooding is a river that overflows its banks during heavy snowmelt or rainfall. People who live or own businesses near rivers or estuaries must be prepared for flood damage year after year.
Wetlands are extremely important as flood mitigation agents. Wetlands act as a natural sponge to absorb extra water safely. Communities that preserve natural wetlands or even create new ones are likely to fare better during heavy rainfall or storm surges. Conversely, communities that destroy or develop wetlands are likely to experience destructive ‘areal flooding’ which occurs when there is no place for the water to go. Areal flooding occurs when wetlands are not available, and the land surface is saturated or non-permeable, such as concrete.
A full 17% of urban land resides within the 100-year flood plain. This is very bad news for these areas, as we have seen these so-called 100-year floods happening with increasing frequency- much more often than every 100 years!
Floods can happen even in a desert. As our climate changes and weather patterns shift, heavy rainfall can occur in places that were formerly reliably dry. Deserts, with arid soil and little vegetation, cannot absorb water quickly, leading to flooding.
Flood prevention measures return almost $5 for every $1 invested. With floods becoming more common every year, those who own homes or other properties must now race to invest in flood panels and other mitigation methods before heavy losses are incurred.
