Identifying groundwater flood risk

Groundwater flooding occurs when the water table, the water level below ground, rises above the ground surface.

During periods of heavy rainfall, the water level in the ground may rise to such an extent that it floods basements, or the emergence of groundwater at the surface may cause damage to properties and infrastructure.

In simple terms, groundwater flooding is caused by the soil and bedrock below reaching and exceeding its water holding capacity.

It is not the gathering of water on paved surfaces or the runoff of surface water down slopes, and it is largely unrelated to a location's distance from a watercourse. Further information on groundwater flooding can be found on the British Geological Survey's website (opens in a new window).

Unfortunately, unlike fluvial (river) flooding and surface water flooding, there are no freely available groundwater flood risk maps.

The British Geological Survey has recently produced the first national hazard data set for groundwater flooding which is available at a cost directly from The BGS (accessible here (opens in a new window)).

More generally however, groundwater flooding is most likely to occur in areas with underlying permeable rocks, called aquifers. These can be regional in scale, such as large areas of chalk or sandstone, or more local scale aquifers. To find out if your property or workplace is located on an aquifer, follow this link to the Environment Agency's database (opens in a new window).

We have a data set which has records of previous flood events that we have been informed about, including incidences of groundwater flooding. Please contact us for queries of this dataset for specific areas.