Types of flooding

When considering flooding we often think of rising rivers and coastal inundation, however there are many different forms of flooding - some of which you may be vulnerable to, irrespective of your proximity to a body of water.

Fluvial (river) flooding

This is the most well known type of flooding, and is where 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 by definition is the most likely area to flood.

Thankfully, river levels are closely monitored therefore this type of flooding can often be forecasted - although sudden and intense rainfall can often cause flash flooding, severely limiting the length of any prior warning, which is why you should always respond quickly to any flood warnings issued.

Groundwater flooding

Less well known, but still extremely problematic, groundwater flooding occurs as a consequence of the earth becoming 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 overwhelm this process, causing 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 is another extremely problematic form of flooding, which forms as a result of heavy rainfall being unable to soak into the earth. This can occur for a number of reasons, such as the earth already being fully saturated, or due to the rain falling on an impermeable surface such as roads and car parks.

Whilst man-made surfaces are designed to drain any water away, heavy rainfall can overwhelm these drains and result in surface water flooding - often leaving roads impassible and flooding nearby properties.

As surface water flooding can be triggered by just a recently blocked drain or sudden intense rainfall, this type of flooding is extremely difficult to predict. It can also occur almost anywhere, which is why even those homeowners whose properties are not usually at risk should ensure they protect themselves and are prepared for any potential flooding.