Flooding occurs naturally along every river and coastal areas. Flood waters can carry nutrient-rich sediments which contribute to a fertile environment for vegetation. Floodplains are beneficial for wildlife by creating a variety of habitats for fish and other animals.

Floodplains can be small, large, and at times huge. They often create good agricultural land as they get sediment carrying floodwaters that enrich the soil. In fact, floodplains are lands built up from soil left by floods. Floodplains provide the space for rivers to spread their waters.

Flood plains are naturally very fertile due to the river sediment which is deposited there. This sediment is good for growing plants on the flood plain.

Flood plains are formed when a meander erodes side ways as it travels down stream. when a river breaks it’s banks, it leaves behind layers of alluvium (silt) These are gradually build up to create the floor of the plain.

Levees occur in the lower course of a river when there is an increase in the volume of water flowing downstream and flooding occurs. When the river floods, the sediment spreads out across the floodplain. When a flood occurs, the river loses energy.

(iv) How are flood plains formed? Answer: When a river overflows its banks, it results in the flooding of the area surrounding it. When it floods, it deposits a layer of fine soil and other material called sediments. Thus, forming a fertile layer of soil called flood plains.

A flood plain is a flat area on the edge of a river, where the ground consists of soil, sand, and rock left by the river when it floods.

Most floodplains are formed by deposition on the inside of river meanders and by overbank flow. Wherever the river meanders, the flowing water erodes the river bank on the outside of the meander, while sediments are simultaneously deposited in a point bar on the inside of the meander.

A flood zone is a geographic area that the Federal Emergency Management Agency (FEMA) has defined according to flood risk. FEMA has designated several flood zones, including moderate- to low-risk areas, high-risk areas and undetermined risk areas.

If you want to build a new home in a floodplain area you need to make special plans to ensure that it will not suffer flood damage. It is just as important to make sure that it is properly removed from the floodplain. If the house is in a flood plain then the bank is required to make the borrower have flood insurance.

The land can no longer absorb rainfall if it is built over; instead, water runs off impermeable surfaces into drains which can become overwhelmed, and into rivers, increasing the flood risk in multiple areas.

When deforestation takes place, the top layer of soil can be dislodged – this is also known as soil erosion. When the top layer of soil is unstable, it is unable to retain any of the water that falls on it, resulting in increased surface run-off, which, in turn, increases the risk of flooding.

Flood risk occurs in low lying areas of land such as: flood plains….Minimising the risk

• ensuring the building is located on the highest section of the site.
• building away from natural drainage paths or channels.
• making the finished floor level of the lowest floor well above (600 mm minimum) the maximum flood level.

The Environment Agency provides live maps which give information about long-term flood risk to properties. Its online postcode search will enable you to find out if the area you are in is in danger of being flooded.

Do not walk, swim or drive through flood waters. Turn Around, Don’t Drown!

• Evacuate if told to do so.
• Move to higher ground or a higher floor.
• Stay where you are.

The duration of floods can last from several hours to months at a time. The period of a flood is dependent on factors including rainfall rate time span, soil and ground conditions, and topography. There are four general types of flooding: river, coastal, urban and flash floods.