Flooding impacts peoples’ lives as well as properties. This can be due to damaging or losing valuable and sentimental items, being forced to leave a home, or temporarily having to close a business.
The average household insurance claim is around £32,000 and those affected can sometimes be out of their property for weeks, or months at a time often with daunting clean-up and repair work required. All of this can take a toll on people’s physical and emotional wellbeing.
In 2021, an estimated 5.2 million properties were reported to be at risk from flooding in England alone according to the Environment Agency. Realistically, flooding can happen anywhere and at any time. Unfortunately, flooding is likely to happen more often with climate change and urbanisation. Improving flood risk management and flood resilience in communities is essential.
Flooding can be categorised based on their source,
or their causes. These are:
Occurs when rivers overflow their banks, usually due to prolonged heavy rainfall upstream. These can also be called fluvial, or riverine flooding.
Coastal areas can experience flooding, where sea water floods coastal areas due to high tides and/or wind creating storm surges (abnormally high sea water).
Occurs when excessive rainfall overwhelms drainage systems or rain cannot soak into (infiltrate) the soil, leading to water accumulating on the surface and generating runoff. It often happens in urban areas with poor or inadequate drainage infrastructure. Flooding caused by rainfall and runoff exceeding the capacity of drains and sewers is often called pluvial flooding.
This is when surface water, sewage and wastewater surcharge or overflow into streets or homes (sometimes through toilets and drains) due to blockages or overloaded sewerage systems. This type of flooding usually occurs when heavy rainfall overwhelms drainage systems. Sewer flooding can lead to significant health hazards as it carries pathogens and contaminants.
Heavy and prolonged rainfall can saturate the ground, leading to a rise in the water table and water coming closer to the surface. This can result in water seeping into basements and low-lying areas, causing localised and often prolonged flooding.
Similarly to river or surface water, heavy rain can cause water to overflow slowly. Reservoir flooding can also happen if a dam fails or breaches, releasing a large amount of water downstream.
Understanding these different types of floods is helpful in preparing for flooding, as mitigation strategies can vary based on the type of flooding expected. For some of the flooding, like surface water or sewer flooding it’s difficult to monitor and predict the risks.
