Types of flooding

There are different types of flooding which can occur almost anywhere - not just near to rivers and coasts.

River flooding (fluvial flooding)

This is the most well known type of flooding. It happens when the volume of water in a river exceeds its capacity, causing it to overflow onto low-lying adjacent land. This adjacent land is often referred to as a flood plain, and is the most likely area to flood.

Thankfully, river levels are closely monitored therefore this type of flooding can often be forecasted. However, sudden and intense rainfall can often cause flash flooding, meaning little warning is given, so you should always respond quickly to any flood warnings issued.

The Environment Agency and other partners are working together to reduce flood risk, secure the local economy and enhance the River Thames through a proposed programme of projects and investment known as the River Thames Scheme.

Groundwater flooding

Groundwater flooding occurs when the earth becomes completely saturated with water. Rainfall naturally soaks into the ground and travels through soil and rock pores to reach rivers, however prolonged heavy rainfall can cause the groundwater level to rise and eventually reach the surface.

Groundwater can usually first be identified in buildings with basements and cellars.

Surface water flooding

Surface water flooding happens when heavy rainfall is unable to soak into the earth. This could be because the earth is fully saturated, or because the surface is impermeable, such as concrete or tarmac roads and car parks.

Man-made surfaces are designed to drain water away but heavy rainfall can overwhelm these drains, causing surface water flooding. This often affects roads and can cause flooding in nearby properties.

Surface water flooding can be triggered by a recently blocked drain or sudden intense rainfall, so this type of flooding is extremely difficult to predict. It can occur almost anywhere, which is why all homeowners should protect themselves and prepare for any potential flooding.