Floods and what to do when they occur
It is the rainy season; more lives may be lost due to flooding.
A flood is the overflow of a large amount of water beyond its normal confines, especially over what is normally dry land, may occur from water bodies such as rivers, lakes, dams or even oceans in which the water overflows or breaks banks, resulting in some of that water escaping its usual boundaries. Flooding may also occur due to an accumulation of rainwater on saturated ground.
Whenever flooding takes place, there is possibility of loss of life, hardship for people and extensive damage to property. Some floods occur abruptly and recede quickly whereas others take several days or even months to form and to recede because of various topographic factors.
Causes of flooding
• High rainfall intensity over a prolonged period
When infrastructure drainage systems to remove rainwater appropriately into reservoirs are overwhelmed and the water does not drain as quickly as it needs to, water will back up and rise into dwellings and other structures.
• Overflowing rivers
Not necessarily to have heavy downpours to experience flooding, more so people living upstream from rivers. Rivers with dams not managed effectively can contribute to flooding for those living upstream.
• Broken dams
Aging dam walls and water gates can fail to contain the rising water levels in the dam. Walls can unleash torrents of water to unsuspecting households.
• Storm surges and tsunamis
Storm surges related to hurricanes and other storms can lead to significant flooding, as can tsunamis that are caused by underwater earthquakes.
• Large paved areas
In large urban areas where large areas are paved and roads are tarred, the surface becomes impermeable, resulting in water being unable to sink into the ground. Subsequently flooding occurs even with a small amount of rain which could have been handled easily by unpaved areas.
• Clogged drainage systems
Uncontrolled littering results in drainage systems clogging and prevents rain water from draining quick enough through the system.
• Developments in a natural waterway
Water naturally flows from a high-level area to low-laying areas. Poor developments in low-laying areas will result in water damming and flooding the area.
Types of floods
• Flash floods
Generally causes greater loss of life and occur when runoffs from excessive rainfall cause a rapid rise in water heights of streams or normally dry channels.
• River floods
Generally causes greater loss of property.
Floods cause wide-scale devastation. It affects everyone negatively. It doesn’t differentiate between the rich and the poor, the young and the old. It damages bridges and washes away automobiles, crops and livestock, etc. Floods can also be caused by pollution.
Safety tips on flooding
Planning and preparation are of paramount importance before a flood because you can save lives.
• Have a family evacuation plan. Tornadoes, hurricanes and other natural disasters require people to have a plan on how to safely evacuate their homes.
• Have the essentials on hand. Keep at least three days of water, non-perishable food and any important medications on hand so it will be there when needed.
• Prepare your home and family. If you know a pending storm is likely to cause major flooding, have bags packed and ready in case you need to leave quickly.
• When evacuating, if possible, disconnect utilities and appliances before you leave to minimise the risk of fire and electrical hazards. Close and lock all windows and doors.
• Stay away from floodwaters. If you come upon a flowing stream where water is above your ankles, use an alternative route.
• When the flooding water covers the surface of the bridge, do not cross. The bridge might have been washed away or the water stream might be strong enough to wash your vehicle or yourself away. Even if you drive a heavy truck, do not take a chance.
• Be especially cautious at night when it’s harder to see flood danger.
• Keep children and pets out of the water. Water might be polluted and full of debris which might be dangerous to human life.
• Go to higher ground and avoid areas subject to flooding.
• Do not attempt to walk or drive through flowing streams or flooded roadways.
• Listen to the direction of local officials and stay updated by following local weather and news reports.
• If you come in contact with floodwaters, wash your hands with soap and disinfected water.
• After the floods, check for structural damage before entering your home to avoid being trapped in a building collapse.
• If your home was affected by flood water, keep power off until a qualified electrician has inspected your system for safety.
• Boil water for drinking and food preparation until authorities tell you that your water supply is safe.
• Prevent mounds by removing wet contents immediately.
• Wear gloves and boots to clean and disinfect.
For any life-threatening emergency call local the emergency and disaster management call centre on these numbers:
• 10177 – national toll-free number
• 112 – cellphone
• 011 458 0911 – life-threatening Ekurhuleni emergency line
