Flood is a natural event when water overflows its banks into normally dry land. Depending on the cause and duration, it can have different impacts on communities and the environment.
When flooding occurs, people are put at risk of losing or damaging their homes and personal belongings. This can lead to stress, financial loss and emotional trauma. In addition, floodwaters may carry sewage and other chemicals that pose a health risk and increase the likelihood of waterborne diseases. Flooding can also interrupt public services like electricity, wastewater and telecommunications. It can also contaminate drinking water which is especially dangerous for those on private wells.
People are at risk of drowning when caught in flood waters. Just 6 inches of rushing floodwater can knock over an adult, and 1-2 feet of water can carry away most cars. Other risks include being swept away by fast-flowing currents, sand, debris or falling trees and power lines. Wild or stray animals may be stranded and present dangers of disease or bites.
The environment can be affected by floods as well, including soil erosion, habitat destruction and disease proliferation. Invasive weeds can take hold and compete with native vegetation for space, and sedimentation can affect water quality and habitats. Animals can be displaced or killed, such as when the floods of 2012 swamped Kaziranga National Park in India, killing hundreds of one-horned rhinos (Rhinoceros unicornis).
People living in areas that are prone to flooding can prepare for disasters by taking steps to protect their homes, businesses and property. They can also improve the condition of their local drainage systems and reduce the amount of impervious surfaces in their streets and buildings through the use of green infrastructure, such as water retention ponds, porous pavement and wetlands.