What is a flash flood?

Flash flooding happens when an exceptional amount of rain falls in a very short time. This type of flood happens very quickly and is particularly dangerous and extremely destructive, so being prepared could save lives and property.

Cartoon flooded house icon. Flood water is past the door level and the car is submerged.

Climate change
With our steep sided valleys and riverside communities Calderdale is more vulnerable to the effects of climate change. In recent years, the number and severity of flooding events in the borough has greatly increased. Our climate has change and Calderdale is flooding more frequently than at any time in history. Find out more at Climate emergency | Calderdale Council.

The most important thing you can do is take the risk of flash flooding seriously.
Flash flooding can happen very quickly, there is often no time to issue flood warnings beforehand. However, the free Floodline service will give you advance warning of flooding from rivers and the sea. You can sign up for free flood warnings here or by phoning Floodline on 0345 988 1188.

The best ways to protect yourself from these kind of events is to familiarise yourself with your local area. Are there streams, culverts, roads and drains which are vulnerable to downpours? If you are new to an area, talk to your neighbours or local flood group and find out if they’ve experienced flash flooding before.

If you live in an area specifically at risk of flash flooding, consider writing a personal flood plan and investing in property level protection. You could also install sustainable drainage systems to slow the flow of rainwater into drains, gutters and rivers.

Flash Flooding

Be aware and know the signs
It is important to know what signs to look for in your location so that you can ACT FAST.

Watch out for the following, and treat them as signs that a flash flood could be on its way:

heavy rain or severe weather reports.
rising water levels with churning dark water.
a build-up of debris in rivers or streams.

What to do if a flash flood happens
Take these quick and simple measures to minimise the impact on you and your property:

Listen to local radio and TV for warnings and advice.
Move furniture and valuables upstairs if you can.
Roll up carpets and rugs if possible and move them out of harm’s way.
Put plugs in downstairs sinks and baths and weigh them down.
Bring outdoor pets indoors and upstairs where possible.
Prepare a pack with essential items i.e. prescriptions, important documents, baby items etc.
Turn off the gas and electricity supply.
Evacuate if asked to do so by the emergency services.
Never walk or drive through floodwater, as there may be hidden dangers such as open manholes.
Keep yourself safe; dial 999 if your life or health is in danger.