Flooding means there is an excess of water on land that is normally dry. Floods can be caused by heavy rainfall, hurricanes, or a lack of proper drainage in urban areas where there is little open soil to absorb water. Floods can be prevented with proper planning and adoption of effective mitigation measures, particularly in areas prone to flooding.
Improving water drainage helps control floods by facilitating easy flow of excess water, especially in urban areas during flash floods. Drainage efficacy can be improved by rehabilitating and cleaning water drainage systems, including removing debris and solid waste from drainage systems like storm drains and French drains, de-silting trenches and underground water channels and building galleys. Effective drainage systems can ensure flood waters find a clear waterway, leading to non-risk areas.
Harvesting Rain Water
Harvesting rainwater involves collecting and storing rainwater and can not only prevent floods, it can also curb urban water scarcity. Harvested rain water can be cleaned for human consumption and distributed to people in rural areas, as well as urban areas in times of water scarcity. Rain water harvesting is carried out in different ways, including building ponds, storm drains, water retention basins and flood-control dams.
Building Dikes and Levees
Dykes and levees are flood-control structures built to fight river flooding and water surges. Dykes and levees restrain rivers during floods by providing artificial water channels that prevent runoffs from bursting floodplains. Floodplains are natural waterways that carry excess river water during heavy rainfall. Dyke engineers/constructors alter and develop floodplains by building dykes and levees to boost flood-prevention when floodplains well up.
Canals are artificial water channels that can be crucial to flood prevention. Canals facilitate control of water levels passing through, and form linear reservoirs and water locks. During flooding, excess water is channelled through canals to non-risk areas further downstream or to other areas with high demand for water, such as arid and semi-arid areas. Canals can also be used to lock excess flood waters in its linear reservoirs to prevent flooding and store water for future use.