Groundwater flooding: Are you at risk?

November 24, 2021
2 min read

Groundwater flooding

Floods can happen anywhere and at anytime.

The most common sources of flooding are:

river flooding.
coastal flooding
surface water flooding
reservoir flooding
flooding from groundwater

Flooding from groundwater can happen when the level of water within the rock or soil that makes up the land surface (known as the water table) rises. The level of the water table changes with the seasons due to variations in long term rainfall and water abstraction.

When the water table rises and reaches ground level, water starts to emerge on the surface and flooding can happen.

Key features of flooding from groundwater:

Flooding will usually occur days or even weeks after heavy or prolonged rainfall.
Flooding may occur for a long time, often lasting several weeks.
The water doesn’t always appear where you would expect it to (i.e. valley bottoms). It may also emerge on hillsides.
Water may rise up through floors rather than coming in through doors.

Flooding from groundwater is most common in areas where the underlying bed rock is chalk, but it can also happen in locations with sand and gravel in the river valleys. If you live in an area that could be affected by flooding from groundwater then this guide is for you. It contains useful information to help you reduce the impact of groundwater flooding to your property.

Are you at risk of groundwater flooding?

Mapping the risk of flooding from groundwater is complex and is currently not possible.

There are no flood risk maps for groundwater. If you want to find out if your property could be at risk of flooding from groundwater or may have flooded in the past you should contact your Lead Local Flood Authority.

Lead Local Flood Authorities (LLFAs) have powers to carry out risk management activities associated with flooding from groundwater. Your LLFA is either the unitary authority or the county council for your area. LLFAs work with other organisations, including the Environment Agency, to manage this risk.

It they do not have any information on flooding from groundwater in your area you may find it helpful to contact one of the following:

Your local Environment Agency office.
Your parish or town council
The Highways Authority
Any flood wardens or Flood Action Groups in your area.

If you are still unsure whether your home is at risk you may wish to carry out a flood risk assessment. To do this, you will need to contact a professional such as a consulting engineer or chartered surveyor.

The Environment Agency is responsible for providing warnings for flooding from rivers and the sea. In some areas they also provide messages about flooding from groundwater.

Their free service can send you messages by phone, email, text message or fax when a flood is expected in your area.

Floodline can also give you practical flooding advice and a Quickdial number to help you easily access information on flooding in your area.