Flooding is dangerous and can be a frightening and stressful situation. There are 5.2 million homes in the UK which are at risk of flooding through different issues and 60% of those in flood risk areas have now taken precautions to protect their properties. Yet there are still millions who have not and need to put a plan in place.
Whilst those living outside known flood risk areas may not feel they need to be concerned about the possibility of water entering their home, they could still suffer from flooding in extreme cases and endure the cost of a clear up in the aftermath of water ingress just as much as those who are at a higher risk.
These are the different kinds of flooding which can affect those in the UK.
There are 2.4 million properties at risk from coastal flooding. This is caused by the sea or rivers. Issues arise with tidal changes or inclement weather and these can often be sudden and have a ferocity which is unpredictable. This is a temperamental situation people live with all year round and have to be well prepared when a flood does strike.
Storm surges can cause coastal flooding and these are often a natural event. However, human intervention on the coastal environment over the centuries has exacerbated the problem.
Groundwater flooding takes place when there have been excessive amounts of rain and the ground becomes waterlogged. The soil simply cannot hold the water and it rises to the surface and as time passes by becomes deeper.
Groundwater flooding will most likely to take place in low-lying areas. When there are abnormal amounts of water in underground springs, it rises up through the layers of permeable rock and usually from higher areas into lower land areas. Groundwater flooding can be extensive when it occurs because large regions of land may have a substrata of chalk or sandstone which allow water from excessive rainfall to easily rise through these types of minerals.
Urban areas are often the worst affected by flash flooding. Ancient drainage systems are unable to cope with a sudden and heavy rainfall and surface water is the result. Of all homes in the UK susceptible to flooding, half fall into the category of surface water issues due to flash flooding occurring. The situation has been exacerbated due to the growing number of gardens which have been concreted over rather than being left as soil or lawn.
Flash flooding can give people time to prepare as they typically take six hours from the beginning of the event to then culminate in the start of a flood. They can be very dangerous; water moving at 2.7 metres per second – the average speed for this kind of floodwater – can move rocks weighing 45 kg. They also create a great amount of debris which can easily injure anyone trying to travel through the waters.
Also known as overbank flooding, this type of disaster takes place when a river overflows and the banks break. This takes place after large amounts of rain, snow or ice and the natural watercourse cannot take any more water.
The effect of fluvial flooding is that the water will spread across the surrounding land. If the land is wide and flat, the spread can be large and once the water levels have settled they will not travel with any great speed and will dissipate very slowly. If it is a hilly area, the danger is the speed of the moving water which can be very destructive in a short space of time.
Precautions to take
As anyone can be affected by flooding, it’s wise to give thought to what you can do should there be a risk of flooding. For those by a water course such as a river, self-maintenance of river beds and banks are important and there should be no obstructions put in place which stop the natural water flow during non-flood periods.
For anyone who does not live near a coastal area, it’s still wise to be aware. Keep the telephone numbers of the local water authority and highways department close to hand and look to deploy flood protection as soon as there is a warning of an impending problem.