Flooding like this is very rare; but there are many narrow steep-sided valleys in Dorset where, after very heavy rainfall, water levels can increase very quickly.
Flash flooding is caused by intense rainfall. Flash floods are rare but can be incredibly destructive. There are two types of flash flooding:
Localised flooding – this is where the drainage is not able to cope with the intense rainfall and so the rain water runs down the streets and into buildings. This often happens in urban areas
Severe flash flooding – this is when heavy rainfall runs off the land and quickly swells rivers and streams. It happens in mainly steep-sided valleys which act as a funnel for the rainwater. This is the most destructive form of flooding, moving rocks, tearing out trees, sweeping away vehicles and destroying buildings, walls and bridges.
The Environment Agency give four simple steps that will help you stay safe if you are involved in a flood.
Step 1 – Be aware
Listen for weather warnings and flood alerts on Wessex FM 96 and 97.2 FM
Step 2 – Move to a safe place
Try to seek shelter in a safe place. If there are no buildings to shelter in, and it is safe to do so, move to higher ground away from the flow of water.
Step 3 –Do not walk or drive through floodwater
Most injuries and deaths are caused during a flood happen when people try to cross a watercourse on foot or in a vehicle.
It takes only 15cm (6 inches) of fast flowing water to knock over an adult
There may be other dangers in the water including rubble, vegetation and exposed drains
It takes less than 60cm (2 feet) of water to lift and wash away a 4x4 car
Step 4 – Stay safe
Be patient and try to stay dry, warm and calm.
The Environment Agency are working with communities and Parish Councils Nationally to raise awareness and give advice on how to stay safe in floods.
For more information on preparing for flooding please visit www.environment-agency.gov.uk